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Biochar and hydrochar have garnered widespread attention owing to their excellent performance in environmental remediation, carbon sequestration, and resource utilization from biowaste. Studies on the release potential of dissolved organic matter (DOM) have been limited, and the distinction between biochar and hydrochar remains unclear. In this study, pine sawdust was utilized as a model precursor with the aim of comparing the release quantity, components, and properties of DOM from biochar (BDOM) and hydrochar (HDOM) under various simulated conditions. The amount of DOM released by hydrochar (38.20-190.49 g/kg) was significantly greater than that released by biochar (0.57-11.96 g/kg), and more DOM was released at higher temperatures and pH values. BDOM consists of three categories of components, namely, humic-like, protein-like, and benzoic acid-like and tyrosine-like substances compounds, whereas HDOM consists of four categories of components, namely, two categories of humic-like compounds and two categories of protein-like compounds. By using ESI-FT-ICR-MS technology, 8586 compounds in BDOM and 6428 compounds in HDOM were identified. A total of 4665 unique compounds were found in BDOM, 1416 unique compounds were found in HDOM under alkaline release conditions, and HDOM contained more unique compounds than those found in other environments. CRAM/lignin-like compounds made up the majority of the released DOM and reached 31.01-65.35 % for BDOM and 54.79-73.05 % for HDOM. These findings revealed significant differences in the release potential of DOM from biochar and hydrochar, and further behavior research is needed to guide future applications of char materials in the environment and agriculture fields., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Mangroves are key components of productive ecosystems that provide a multitude of ecosystem goods and services. How these species will respond to future climates with more frequent and severe extreme temperatures has not received much attention. To understand how vulnerable mangroves are to future warming, we quantified photosynthetic heat tolerance and estimated thermal safety margins for thirteen mangrove species from the southwestern Indian coast. We quantified heat tolerance as temperatures that resulted in a 5 % (T 5 ) and 50 % (T 50 ) decline in photosystem II function, and thermal safety margins (TSM) as the difference between T 50 and maximum leaf temperatures. T 50 ranged from 48.9 °C in Avicennia Marina to 55.3 °C in Bruguiera gymnorhiza, with a mean of 53.3 °C for the thirteen species. Heat tolerance was higher for species with bigger leaves which experience higher leaf temperatures, but was not related to the other leaf traits examined. Heat tolerance was exceptionally high in these mangroves compared to other woody species. With their high tolerance and large safety margins these mangroves may be relatively less vulnerable to future climates with higher temperatures., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In recent years, the oak lace bug, Corythucha arcuata, has emerged as a significant threat to European oak forests. This species, native to North America, has in the last two decades rapidly extended its range in Europe, raising concerns about its potential impact on the continent's invaluable oak populations. To address this growing concern, we conducted an extensive study to assess the distribution, colonization patterns, and potential ecological niche of the oak lace bug in Europe. We gathered 1792 unique presence coordinates from 21 Eurasian countries, utilizing diverse sources such as research observations, citizen science initiatives, GBIF database, and social media reports. To delineate the realized niche and future distribution, we employed an ensemble species distribution modelling (SDM) framework. Two future greenhouse gas scenarios (RCP 4.5 and RCP 8.5) were considered across three-time intervals (2021-2040, 2061-2080, and 2081-2100) to project and evaluate the species' potential distribution in the future. Our analysis revealed that significant hotspots rich in host species occurrence for this invasive insect remain uninvaded so far, even within its suitable habitat. Furthermore, the native ranges of Turkey oak (Quercus cerris L.) and Hungarian oak (Quercus frainetto L.) species offer entirely suitable environments for the oak lace bug. In contrast, the pedunculate oak and sessile oak distribution ranges currently show only 40 % and 50 % suitability for colonization, respectively. However, our predictive models indicate a significant transformation in the habitat suitability of the oak lace bug, with suitability for these two oak species increasing by up to 90 %. This shift underlines an evolving landscape where the oak lace bug may exploit more of its available habitats than initially expected. It emphasises the pressing need for proactive measures to manage and stop its expanding presence, which may lead to a harmful impact on the oak population across the European landscape., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Climate change, particularly droughts and heat waves, significantly impacts global photosynthesis and forest ecosystem sustainability. To understand how trees respond to and recover from hydrological stress, we investigated the combined effects of soil moisture and atmospheric vapour pressure deficit (VPD) on seedlings of the two major European broadleaved tree species Fagus sylvatica (FS) and Quercus robur (QR). The experiment was conducted under natural forest gap conditions, while soil water availability was strictly manipulated. We monitored gas exchange (net photosynthesis, stomatal conductance and transpiration rates), nonstructural carbohydrates (NSC) concentration in roots and stomatal morphometry (size and density) during a drought period and recovery. Our comparative empirical study allowed us to distinguish and quantify the effects of soil drought and VPD on stomatal behavior, going beyond theoretical models. We found that QR conserved water more conservatively than FS by reducing transpiration and regulating stomatal conductance under drought. FS maintained higher stomatal conductance and transpiration at elevated VPD until soil moisture became critically low. QR showed higher intrinsic water use efficiency than FS. Stomata density and size also likely played a role in photosynthetic rate and speed of recovery, especially since QR with its seasonal adjustments in stomatal traits (smaller, more numerous stomata in summer leaves) responded and recovered faster compared to FS. Our focal species showed different responses in NSC content under drought stress and recovery, suggesting possible different evolutionary pathways in coping with stress. QR mobilized soluble sugars, while FS relied on starch mobilization to resist drought. Although our focal species often co-occur in mixed forests, our study showed that they have evolved different physiological, morphological and biochemical strategies to cope with drought stress. This suggests that ongoing climate change may alter their competitive ability and adaptive potential in favor of one of the species studied., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The climate change scenarios RCP 4.5 and RCP 8.5, with a representative concentration pathway for stabilization of radiative forcing of 4.5 W m -2 and 8.5 W m -2 by 2100, respectively, predict an increase in temperature of 1-4.5° Celsius for Europe and a simultaneous shift in precipitation patterns leading to increased drought frequency and severity. The negative consequences of such changes on tree growth on dry sites or at the dry end of a tree species distribution are well-known, but rarely quantified across large gradients. In this study, the growth of Quercus robur and Quercus petraea (Q. spp.) and Pinus sylvestris in pure and mixed stands was predicted for a historical scenario and the two climate change scenarios RCP 4.5 and RCP 8.5 using the individual tree growth model PrognAus. Predictions were made along an ecological gradient ranging from current mean annual temperatures of 5.5-11.4 °C and with mean annual precipitation sums of 586-929 mm. Initial data for the simulation consisted of 23 triplets established in pure and mixed stands of Q. spp. and P. sylvestris. After doing the simulations until 2100, we fitted a linear mixed model using the predicted volume in the year 2100 as response variable to describe the general trends in the simulation results. Productivity decreased for both Q. spp. and P. sylvestris with increasing temperature, and more so, for the warmer sites of the gradient. P. sylvestris is the more productive tree species in the current climate scenario, but the competitive advantage shifts to Q. spp., which is capable to endure very high negative water potentials, for the more severe climate change scenario. The Q. spp.-P. sylvestris mixture presents an intermediate resilience to increased scenario severity. Enrichment of P. sylvestris stands by creating mixtures with Q. spp., but not the opposite, might be a right silvicultural adaptive strategy, especially at lower latitudes. Tree species mixing can only partly compensate productivity losses due to climate change. This may, however, be possible in combination with other silvicultural adaptation strategies, such as thinning and uneven-aged management., Competing Interests: Declaration of competing interest We have no conflicts of interest to disclose., (Copyright © 2024. Published by Elsevier B.V.)

In situ measurement of the bioavailability of organic pollutants in soil is crucial for understanding their environmental behavior and assessing health risks. Due to the high heterogeneity of soil, microscale determination is crucial for achieving high accuracy, but few methods are available. In this study, microsized probes coated with polydimethylsiloxane (PDMS) were used to measure the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in soil in situ. The concentrations of PAHs enriched by the PDMS-coated probes correlated well with the results of bioassays using earthworms (R 2  = 0.92-0.99) and ryegrass roots (R 2  = 0.92-0.99). Compared with other chemical extraction methods, such as n-butanol extraction, the proposed method has advantages such as in situ operation, microvolume analysis, and negligible interference to the soil environment. In the soil rhizosphere zone, PAHs bioavailability decreased in the following order: rhizosphere > near-rhizosphere > far-rhizosphere. The bioavailability of PAHs in soil amended with biochar was also successfully characterized by the proposed method. Thus, this study developed an in situ and microscale method to predict the bioavailability of organic pollutants in contaminated soils and provides new insight into migration and transformation processes in rhizosphere soil., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Understanding how trees prioritize carbon gain at the cost of drought vulnerability under severe drought conditions is crucial for predicting which genetic groups and individuals will be resilient to future climate conditions. In this study, we investigated variations in growth, tree-ring anatomy as well as carbon and oxygen isotope ratios to assess the sensitivity and the xylem formation process in response to an episode of severe drought in 29 mature white spruce (Picea glauca [Moench] Voss) families grown in a common garden trial. During the drought episode, the majority of families displayed decreased growth and exhibited either sustained or increased intrinsic water-use efficiency (iWUE), which was largely influenced by reduced stomatal conductance as revealed by the dual carbon‑oxygen isotope approach. Different water-use strategies were detected within white spruce populations in response to drought conditions. Our results revealed intraspecific variation in the prevailing physiological mechanisms underlying drought response within and among populations of Picea glauca. The presence of different genetic groups reflecting diverse water-use strategies within this largely-distributed conifer is likely to lessen the negative effects of drought and decrease the overall forest ecosystems' sensitivity to it., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare that are relevant to the content of this article., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Plant functional attributes are subjected to environmental adjustments, which lead to modulations in forest processes under environmental changes. However, a comprehensive assessment of the relationships between plant traits and carbon stock remains subtle. The present study attempted to accomplish the gap of knowledge by examining the linkages between forest carbon with plant traits within the Banj Oak forest in the Garhwal Himalaya. Twelve individuals from three major species in the Banj Oak forest were randomly selected for trait measurements, and soil samples were collected randomly across the area for evaluation of soil nutrients and carbon. Forest biomass and soil carbon were estimated following standard protocols. A Structural Equation Model (SEM) was applied to establish the relationship between above ground carbon (AGC) and soil organic carbon (SOC) with leaf and stem traits, and soil nutrients. Stem traits were tree height and tree diameter; whereas leaf morphological traits were leaf area, specific leaf area, leaf dry matter content; leaf physiological traits were photosynthesis rate, stomatal conductance, and transpiration rate; and leaf biochemical traits were leaf carbon concentration, leaf nitrogen concentration, and leaf phosphorus concentration. Soil nutrients were available nitrogen, available phosphorus, and exchangeable potassium. Based on SEM results, AGC of the forest was positively correlated with stem traits and leaf physiological traits, while negatively correlated with leaf morphological traits. SOC was positively correlated with soil nutrients and leaf biochemical traits, whereas negatively correlated with stem traits. These findings may support for precise quantification of forest carbon and modeling of forest carbon stocks besides providing inputs to forest managers for devising effective forest management strategies., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

To enhance our understanding of forest carbon sequestration, climate change mitigation and drought impact on forest ecosystems, the availability of high-resolution annual forest growth maps based on tree-ring width (TRW) would provide a significant advancement to the field. Site-specific characteristics, which can be approximated by high-resolution Earth observation by satellites (EOS), emerge as crucial drivers of forest growth, influencing how climate translates into tree growth. EOS provides information on surface reflectance related to forest characteristics and thus can potentially improve the accuracy of forest growth models based on TRW. Through the modelling of TRW using EOS, climate and topography data, we showed that species-specific models can explain up to 52 % of model variance (Quercus petraea), while combining different species results in relatively poor model performance (R 2  = 13 %). The integration of EOS into models based solely on climate and elevation data improved the explained variance by 6 % on average. Leveraging these insights, we successfully generated a map of annual TRW for the year 2021. We employed the area of applicability (AOA) approach to delineate the range in which our models are deemed valid. The calculated AOA for the established forest-type models was 73 % of the study region, indicating robust spatial applicability. Notably, unreliable predictions predominantly occurred in the climate margins of our dataset. In conclusion, our large-scale assessment underscores the efficacy of combining climate, EOS and topographic data to develop robust models for mapping annual TRW. This research not only fills a critical void in the current understanding of forest growth dynamics but also highlights the potential of integrated data sources for comprehensive ecosystem assessments., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Biowaste-derived hydrochar is an emerging close-to-natural product and has shown promise for soil improvement and remediation, but the environmental behavior of the dissolved organic matter released from hydrochar (HDOM) is poorly understood. Focusing on the typical mulch film plasticizer diethyl phthalate (DEP), we investigated the effect of HDOM on the sorption behavior of DEP on soil. The relatively low concentration of HDOM (10 mg L -1 , 25 mg L -1 ) decreases the sorption quantity of DEP on soil, while it increases by a relatively high concentration, 50 mg L -1 . The transformation from multilayer to monolayer sorption of DEP on soil occurs as the concentration of HDOM increases. The tryptophan-like substance is the main component of HDOM sorbed to soil, reaching 49.82 %, and results in competition sorption with DEP. The soil pores are blocked by HDOM, which limits the pore filling and mass transfer of DEP, but partitioning is significantly enhanced. The surface functional groups in HDOM are similar to those in soil, and chemical sorption, mainly composed of hydrogen bonding, exists but is not significantly strengthened. We identified the specific impact of HDOM on the sorption of organic pollutants on soil and provide new insights into the understanding of the environmental behavior of hydrochar., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Many phenological studies have shown that spring geophytes are very sensitive to climate change, responding by shifting flowering and fruiting dates. However, there is a gap in knowledge about climatic drivers of their distributions and range shifts under climate change. Here we aimed to estimate climate niche shifts for four widely distributed and common geophytes of the nemoral zone of Europe (Anemone nemorosa, Anemone ranunculoides, Convallaria majalis and Maianthemum bifolium) and to assess the threat level under various climate change scenarios. Using MaxEnt species distribution models and future climate change scenarios we found that the precipitation of the warmest quarter was the most important factor shaping their ranges. All species studied will experience more loss in the 2061-2080 period than in 2041-2060, and under more pessimistic scenarios. M. bifolium will experience the highest loss, followed by A. nemorosa, A. ranunculoides, and the smallest for C. majalis. A. ranunculoides will gain the most, while M. bifolium will have the smallest potential range expansion. Studied species may respond differently to climate change despite similar current distributions and climatic variables affecting their potential distribution. Even slight differences in climatic niches could reduce the overlap of future ranges compared to present. We expect that due to high dependence on the warmest quarter precipitation, summer droughts in the future may be particularly severe for species that prefer moist soils. The lack of adaptation to long-distance migration and limited availability of appropriate soils may limit their migration and lead to a decline in biodiversity and changes in European forests., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Understanding how vegetation composition and diversity respond to global changes is crucial for effective ecosystem management and conservation. This study evaluated shifts in understory vegetation after 40 years of conservation within Drawa National Park (NW Poland), to check which plant communities changed the most, and whether vegetation shifts reflect global change symptoms (climate change and pollution) or natural forest dynamics. Using ordination and generalized mixed-effects linear models, we assessed changes in alpha diversity metrics, accounting for taxonomic, functional, and phylogenetic aspects within 170 quasi-permanent plots, surveyed in 1973-85 and resurveyed in 2015-19. We found an overall homogenization of forest vegetation and specific shift patterns in certain forest associations. In coniferous and nutrient-poor broadleaved forests, the overall number of species increased due to the replacement of functionally distinct or specialized species with more ubiquitous species that could exploit increased resource availability. In riparian forests and alder carrs we found either shifts from riparian forest to alder carrs or to mesic broadleaved forests. The most stable communities were fertile broadleaved forests. Our study quantified shifts in taxonomic, functional, and phylogenetic diversity after 40 years of conservation and provides important insights into the shifts in vegetation composition in temperate forest communities. In coniferous and nutrient-poor broadleaved forests we found an increase in species richness and replacement of functionally distinct or specialized species by ubiquitous species, indicating increased resource availability. Shifts between wet broadleaved forests and transition into mesic forests suggest water limitation, which can be related to climate change. The most stable were fertile broadleaved forests fluctuating due to natural stand dynamics. The findings highlight the need for ongoing monitoring and management of ecological systems to preserve their diversity and functionality in the face of global changes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Process-based models and empirical modelling techniques are frequently used to (i) explore the sensitivity of tree growth to environmental variables, and (ii) predict the future growth of trees and forest stands under climate change scenarios. However, modelling approaches substantially influence predictions of the sensitivity of trees to environmental factors. Here, we used tree-ring width (TRW) data from 1630 beech trees from a network of 70 plots established across European mountains to build empirical predictive growth models using various modelling approaches. In addition, we used 3-PG and Biome-BGCMuSo process-based models to compare growth predictions with derived empirical models. Results revealed similar prediction errors (RMSE) across models ranging between 3.71 and 7.54 cm 2 of basal area increment (BAI). The models explained most of the variability in BAI ranging from 54 % to 87 %. Selected explanatory variables (despite being statistically highly significant) and the pattern of the growth sensitivity differed between models substantially. We identified only five factors with the same effect and the same sensitivity pattern in all empirical models: tree DBH, competition index, elevation, Gini index of DBH, and soil silt content. However, the sensitivity to most of the climate variables was low and inconsistent among the empirical models. Both empirical and process-based models suggest that beech in European mountains will, on average, likely experience better growth conditions under both 4.5 and 8.5 RCP scenarios. The process-based models indicated that beech may grow better across European mountains by 1.05 to 1.4 times in warmer conditions. The empirical models identified several drivers of tree growth that are not included in the current process-based models (e.g., different nutrients) but may have a substantial effect on final results, particularly if they are limiting factors. Hence, future development of process-based models may build upon our findings to increase their ability to correctly capture ecosystem dynamics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Water scarcity is a highly complex, multifaceted and dynamic issue, which has become a severe global challenge. Water scarcity is a hyperconnected phenomenon and thus should be studied through nexus approach, however current water-energy-food (WEF) nexus underrepresents the impacts of land use change and climate change on water scarcity. Therefore, this study was investigated to expand the WEF nexus coverage of further systems, improving the accuracy of nexus models for decision-making and narrowing science-policy gap. Current study developed a water-energy-food-land-climate (WEFLC) nexus model to analyze the water scarcity. Modeling the complex behavior of water scarcity enables the analysis of the efficiency of some adaptation policies in addressing water scarcity and will provide suggestions for improving adaptation practices. The results showed that there is a substantial water supply-demand gap in study region, with an excess consumption of 62,361 million m 3 . Under baseline scenario, the gap between water supply and demand will enlarge, leading to water crisis in Iran as our study region. Climate change was found to be the prime cause of exacerbating water scarcity in Iran, raising evapotranspiration from 70 % to 85 % in 50 years, and considerably increasing the water demand in various sectors. In terms of policy/adaptation measure analysis, the results showed that neither supply-side nor demand-side scenarios could solely address water crisis, and mixed supply-demand side interventions can be the most effective policy to alleviate water crisis. Overall, the study suggests that water resource management practices and policies in Iran should be reevaluated to include a system thinking management approach. The results can be used as a decision support tool that can recommend suitable mitigation and adaptation strategies for water scarcity in the country., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Tropical primary forests are being destroyed at an alarming rate and converted for other land uses which is expected to greatly influence soil carbon (C) cycling. However, our understanding of how tropical forest conversions affect the accumulation of compounds in soil functional C pools remains unclear. Here, we collected soils from primary forests (PF), secondary forests (SF), oil-palm (OP), and rubber plantations (RP), and assessed the accumulation of plant- and microbial-derived compounds within soil organic carbon (SOC), particulate (POC) and mineral-associated (MAOC) organic C. PF conversion to RP greatly decreased SOC, POC, and MAOC concentrations, whereas conversion to SF increased POC concentrations and decreased MAOC concentrations, and conversion to OP only increased POC concentrations. PF conversion to RP decreased lignin concentrations and increased amino sugar concentrations in SOC pools which increased the stability of SOC, whereas conversion to SF only increased the lignin concentrations in POC, and conversion to OP just increased lignin concentrations in POC and decreased it in MAOC. We observed divergent dynamics of amino sugars (decrease) and lignin (increase) in SOC with increasing SOC. Only lignin concentrations increased in POC with increasing POC and amino sugars concentrations decreased in MAOC with increasing MAOC. Conversion to RP significantly decreased soil enzyme activities and microbial biomasses. Lignin accumulation was associated with microbial properties, whereas amino sugar accumulation was mainly associated with soil nutrients and stoichiometries. These results suggest that the divergent accumulation of plant- and microbial-derived C in SOC was delivered by the distribution and original composition of functional C pools under forest conversions. Forest conversions changed the formation and stabilization processes of SOC in the long run which was associated with converted plantations and management. The important roles of soil nutrients and stoichiometry also provide a natural-based solution to enhance SOC sequestration via nutrient management in tropical forests., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

The extensive radioactive fallout resulting from the 1986 Chornobyl accident caused tree death near the nuclear power plant and perturbed trees communities throughout the whole Chornobyl exclusion zone. Thirty years into the post-accident period, the radiation continues to exert its fatal effects on the surviving trees. However, to what extent the continuous multi-decadal radiation exposure has affected the radial tree growth and its sensitivity to climate variation remains unascertained. In this comparative study, we measure the Scots pine radial growth and quantify its response to climate at two sites along the western track of the nuclear fallout that received significantly different doses of radiation in 1986. The common features of the two sites allow us to disentangle and intercompare the effects of sub-lethal and moderate radiation doses on the pine's growth and climatic sensitivity. We extend the response function analysis by making the first use of the Full-Duration at Half-Maximum FDHM method in dendrochronology and apply the double-moving window approach to detect the main patterns of the growth-to-climate relationships and their temporal evolution. The stand exposed to sub-lethal radiation shows a significant radial growth reduction in 1986 with a deflection period of one year. The stand exposed to moderate radiation, in contrast, demonstrates no significant decrease in growth either in 1986 or in the following years. Beyond the radiation effects, the moving response function and FDHM enabled us to detect several mutual patterns in the growth-to-climate relationships, which are seemingly unrelated to the nuclear accident. To advance our predictive understanding of the response of forest ecosystems to a massive radioactive contamination, future studies should include quantitative wood anatomy techniques., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this study., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Cistus scrublands are pyrophytic ecosystems and occur widely across Mediterranean regions. Management of these scrublands is critical to prevent major disturbances, such as recurring wildfires. This is because management appears to compromise the synergies necessary for forest health and the provision of ecosystem services. Furthermore, it supports high microbial diversity, opening questions of how forest management practices impact belowground associated diversity as research related to this issue is scarce. This study aims to investigate the effects of different fire prevention treatments and site history on bacterial and fungi co-response and co-occurrence patterns over a fire-risky scrubland ecosystem. Two different site histories were studied by applying three different fire prevention treatments and samples were analyzed by amplification and sequencing of ITS2 and 16S rDNA for fungi and bacteria, respectively. The data revealed that site history, especially regarding fire occurrence, strongly influenced the microbial community. Young burnt areas tended to have a more homogeneous and lower microbial diversity, suggesting environmental filtering to a heat-resistant community. In comparison, young clearing history also showed a significant impact on the fungal community but not on the bacteria. Some bacteria genera were efficient predictors of fungal diversity and richness. For instance, Ktedonobacter and Desertibacter were a predictor of the presence of the edible mycorrhizal bolete Boletus edulis. These results demonstrate fungal and bacterial community co-response to fire prevention treatments and provide new tools for forecasting forest management impacts on microbial communities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Forest management integrating nature conservation aspects into timber production focuses increasingly on small-scale interventions. However, the ecological consequences of gap cuttings remain ambiguous in oak-dominated forests. In the Pilis Gap Experiment, we analyze how combinations of different gap shapes (circular and elongated), and gap sizes (150 m 2 and 300 m 2 ) affect the microclimate and biota of a mature sessile oak-hornbeam forest in Hungary. We first report the changes in direct and diffuse light, soil moisture, daily air and soil temperatures, and relative air humidity in the experimental cuttings in the vegetation season directly following their implementation. Diffuse light had a central maximum and a concentric pattern. Direct light was distributed along a north-south gradient, with maxima in northern gap parts. Soil moisture was determined by gap shape: it increased significantly in the center of circular gaps, with multiple local maxima in the southern-central parts of large circular gaps. Its pattern was negatively related to direct light, and larger spatial variability was present in circular than in elongated gaps. The daily mean air temperatures at 1.3 m increased in all, especially in large gaps. Soil and ground-level temperatures remained largely unchanged, reflecting on light and soil moisture conditions affecting evaporative cooling. Relative humidity remained unaltered. Even though the opening of experimental gaps changed microclimatic conditions immediately, effect sizes remained moderate. Gap size and gap shape were both important determinants of microclimate responses: gap size markedly affected irradiation increase, gap shape determined soil moisture surplus, while soil and air temperatures, and air humidity depended on both components of the gap design. We conclude that 150-300 m 2 sized management-created gaps can essentially maintain forest microclimate while theoretically providing enough light for oak regeneration; and that the manipulation of gap shape and gap size within this range are effective tools of adaptive management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Forests account for nearly 90 % of the world's terrestrial biomass in the form of carbon and they support 80 % of the global biodiversity. To understand the underlying forest dynamics, we need a long-term but also relatively high-frequency, networked monitoring system, as traditionally used in meteorology or hydrology. While there are numerous existing forest monitoring sites, particularly in temperate regions, the resulting data streams are rarely connected and do not provide information promptly, which hampers real-time assessments of forest responses to extreme climate events. The technology to build a better global forest monitoring network now exists. This white paper addresses the key structural components needed to achieve a novel meta-network. We propose to complement - rather than replace or unify - the existing heterogeneous infrastructure with standardized, quality-assured linking methods and interacting data processing centers to create an integrated forest monitoring network. These automated (research topic-dependent) linking methods in atmosphere, biosphere, and pedosphere play a key role in scaling site-specific results and processing them in a timely manner. To ensure broad participation from existing monitoring sites and to establish new sites, these linking methods must be as informative, reliable, affordable, and maintainable as possible, and should be supplemented by near real-time remote sensing data. The proposed novel meta-network will enable the detection of emergent patterns that would not be visible from isolated analyses of individual sites. In addition, the near real-time availability of data will facilitate predictions of current forest conditions (nowcasts), which are urgently needed for research and decision making in the face of rapid climate change. We call for international and interdisciplinary efforts in this direction., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Zweifel Roman reports financial support was provided by Federal Office for the Environment., (Copyright © 2023 Elsevier B.V. All rights reserved.)

In this study, a novel magnetic poly (tetrafluoroethylene, PTFE) (Fe@PTFE) piezoelectric catalytic material was successfully prepared by a simple ball milling treatment. The prepared piezoelectric catalytic material Fe@PTFE exhibited excellent catalytic performance under the activation of ultrasonic (US) and realized the efficient degradation of imidacloprid (IMI) at low concentrations in an aqueous environment. It was demonstrated by various characterization methods that Fe 0 was successfully loaded onto PTFE particles (1-15 μm) by ball milling. The US/Fe@PTFE system exhibited superior IMI degradation efficiency (99 %) and degradation rate (7.81× 10 -2 min -1 ) under ultrasonic polarization with high efficiences of IMI degradation after five cycles. In addition, the system maintained excellent removal efficiencies in the real water matrixes. The mechanism study demonstrated that Fe@PTFE generated a variety of reactive oxygen species ( • OH, 1 O 2 and O 2 •- ) and H 2 O 2 under the irradiation of US, and the production of H 2 O 2 provided the conditions for the continuation of the Fenton-like reaction. Furthermore, the presence of O 2 •- in the system enhanced the recycling efficiency of Fe(III) and Fe(II), which further enhanced the degradation efficiency of the Fenton-like process. This study provides a novel perspective on a PTFE-based ultrasonic piezoelectric catalytic system for the efficient removal of organic pollutants in the environmental field., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2022. Published by Elsevier B.V. All rights reserved.)

Land conversion from natural forests to plantations (e.g., oil palm) in Southeast Asia is one of the most intensive land-use changes occurring worldwide. To clarify the effects of oil palm plantations on water quality, we conducted multipoint river and stream water sampling in peninsular Malaysia at the end of the rainy season over a 3-year period (2013-2015). We measured the major dissolved ions and stable isotope ratios of water (δ 2 H-H 2 O and δ 18 O-H 2 O) and nitrate (δ 15 N-NO 3 - and δ 18 O-NO 3 - ) in water from the upper streams in mountainous forests to the midstream areas of two major rivers in peninsular Malaysia. The electrical conductivity increased, and the d-excess value (as an index of the degree of evaporation) decreased with increasing distance from the headwaters, suggesting the effect of evaporative enrichment and the addition of pollutants. We separated the sampling points into four groups (G1-G4) through cluster analysis of the water quality data. From the land use/land cover (LULC) classification maps developed from satellite images and local information, we found that G1 and G2 mainly consisted of sampling points in forested areas, while G3 and G4 were located in oil-palm-affected areas. The concentrations of major ions were higher in the oil palm areas, indicating the effects of fertilizer and limestone (i.e., pH adjustment) applications. The dissolved inorganic nitrogen concentration did not differ among the groups, but the dissolved organic carbon, total dissolved nitrogen, and δ 15 N-NO 3 - were higher in the oil palm area than in the forested area. Although the nitrogen concentration was low, even in the oil palm area, the significantly higher δ 15 N-NO 3 - in the oil palm area indicated substantial denitrification. This implies that denitrification contributed to the lowering of the NO 3 - concentration in rivers in the oil palm area, in addition to nutrient uptake by oil palm trees., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Masayuki Itoh reports financial support was provided by Japan Society for the Promotion of Science. Masayuki Itoh reports financial support was provided by Research Institute for Humanity and Nature. Ken'ichi Osaka reports financial support was provided by Japan Society for the Promotion of Science. Yoshiko Kosugi reports financial support was provided by Japan Society for the Promotion of Science. Satomi Shiodera reports financial support was provided by Japan Society for the Promotion of Science., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Severe drought events negatively affect tree growth and often cause legacy effects, expressed by smaller tree rings in the post-drought recovery years. While the pattern of reduced tree-ring widths is frequently described the processes underlying such legacy effects, i.e., whether it is due to shorter growth periods or lower growth rates, remains unclear and is investigated in this study. To elucidate these post-drought effects, we examined radial stem growth dynamics monitored with precision band-dendrometers on 144 Douglas fir, Norway spruce and silver fir sample trees distributed along four elevational gradients in the Black Forest (Southwest Germany) during the post-drought years 2019 and 2020. Growth onset of all investigated species occurred between 11 and 24 days significantly earlier in 2020 compared to 2019. Modelling growth onset based on chilling and forcing units and taking the study year into account explained 88-98 % of the variance in the growth onset data. The highly significant effect of the study year (p < 0.001) led to the conclusion, that other factors than the prevailing site conditions (chilling and forcing units) must have triggered the earlier growth onset in 2020. On the other hand, for Douglas fir growth rates were significantly higher in 2020 compared to 2019 (2.9 μm d -1 ) and marginally significantly higher for silver fir (1.3 μm d -1 ), underlining the explanatory power of growth rate on recovery processes in general and suggesting that Douglas fir copes better with droughts, as it recovered faster. Growth dynamics at the beginning of the year showed limited growth for earlier growth onsets, which, however, could not explain the difference between the investigated years. Our results provide evidence that legacy effects of drought events are expressed by a delayed growth onset and a reduced growth rate in the post-drought year and that Douglas fir has a superior recovery potential., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Mangroves continue to be threatened across their range by a mix of anthropogenic and climate change-related stress. Climate change-induced salinity is likely to alter the structure and functions of highly productive mangrove systems. However, we still lack a comprehensive understanding of how rising salinity affects forest structure and functions because of the limited availability of mangrove field data. Therefore, based on extensive spatiotemporal mangrove data covering a large-scale salinity gradient, collected from the world's largest single tract mangrove ecosystem - the Bangladesh Sundarbans, we, aimed to examine (QI) how rising salinity influences forest structure (e.g., stand density, diversity, leaf area index (LAI), etc.), functions (e.g., carbon stocks, forest growth), nutrients availability, and functional traits (e.g., specific leaf area, wood density). We also wanted to know (QII) how forest functions interact (direct vs. indirect) with biotic (i.e., stand structure, species richness, etc.) and abiotic factors (salinity, nutrients, light availability, etc.). We also asked (QIII) whether the functional variable decreases disproportionately with salinity and applied the power-law (i.e., Y = a X b ) to the salinity and functional variable relationships. In this study, we found that rises in salinity significantly impede forest growth and produce less productive ecosystems dominated by dwarf species while reducing stand structural properties (i.e., tree height, basal area, dominant tree height, LAI), soil carbon (organic and root carbon), and macronutrient availability in the soil (e.g., NH4+, P, and K). Besides, species-specific leaf area (related to resource acquisition) also decreased with salinity, whereas wood density (related to resource conservation) increased. We observed a declining abundance of the salt-intolerant climax species (Heritiera fomes) and dominance of the salt-tolerant species (Excoecaria agallocha, Ceriops decandra) in the high saline areas. In the case of biotic and abiotic factors, salinity and salinity-driven gap fraction (high transmission of light) had a strong negative impact on functional variables, while nutrients and LAI had a positive impact. In addition, the power-law explained the consistent decline of functional variables with salinity. Our study disentangles the negative effects of salinity on site quality in the Sundarbans mangrove ecosystem, and we recognize that nutrient availability and LAI are likely to buffer the less salt-tolerant species to maintain the ability to sequester carbon with sea-level rise. These novel findings advance our understanding of how a single stressor-salinity-can shape mangrove structure, functions, and productivity and offer decision makers a much-needed scientific basis for developing pragmatic ecosystem management and conservation plans in highly stressed coastal ecosystems across the globe., Competing Interests: Declaration of competing interest The authors declare no competing interest., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

In this study, three high-performance porous biochars were synthesized by the cocarbonization of Pistia stratiotes-derived precursors (raw biomass, hydrochar and pyrochar) with potassium hydroxide and utilized for the sorption of diethyl phthalate from aqueous solution. The developed pore structure, surface functional groups, high hydrophobicity characteristic and graphene structure of porous biochars contributed to the excellent sorption quantity of up to 813 mg g -1 (C e , 25 mg L -1 ). Among the three precursors, hydrochar-derived porous biochar showed better properties in terms of its specific surface area and hydrophobicity, and it displayed the highest sorption capacity. The sorption kinetics and isotherm experiments confirmed that pore filling and partitioning dominated the sorption capacity while the mass transfer, hydrogen bonding and π-π stacking in the hydrochar limited the sorption rate. This finding helped to propose a feasible method for the efficient utilization of invasive aquatic plants and provided novel insight into the selection of precursors for preparing porous biochars., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Freshwater lakes are important reservoirs and sources of drinking water globally. However, the microbiota, which supports the functionality of these ecosystems is threatened by the influx of nutrients, heavy metals and other toxic chemical substances from anthropogenic activities. The influence of these factors on the diversity, assembly mechanisms and co-occurrence patterns of bacterial communities in freshwater lakes is not clearly understood. Hence, samples were collected from six different impacted lakes in Canada and India and examined by 454-pyrosequencing technology. The trophic status of these lakes was determined using specific chemical parameters. Our results revealed that bacterial diversity and community composition was altered by both the lake water chemistry and geographic distance. Anthropogenic activities pervasively influenced species distribution. Dispersal limitation (32.3%), homogenous selection (31.8%) and drift (20%) accounted for the largest proportions of the bacterial community assembly mechanisms. Homogenous selection increased in lakes with higher nutrient concentration, while stochasticity reduced. Community functional profiles revealed that deterministic processes dominated the assembly mechanisms of phylotypes with higher potential for biodegradation, while stochasticity dominated the assembly of phylotypes with potential for antimicrobial resistance. Bacteroidota (44%) and Proteobacteria (34%) were the most abundant phyla. Co-occurrence network analysis revealed that complexity increased in more impacted lakes, while competition and the nature of anthropogenic activity contributed to species sorting. Overall, this study demonstrates that bacterial community changes in freshwater lakes are linked to anthropogenic activities, with corresponding consequences on the distribution of phylotypes of environmental and human health interest., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Forests play an essential role in mitigating climate change by sequestering carbon dioxide from the atmosphere. The establishment of mixed plantations is a promising way to store carbon (C) in soil compared with monocultures. However, monoculture forests largely dominate the rapid increase in forest areas in China. To optimize afforestation strategies and maximize the subsequent potential of C sequestration, we conducted a meta-analysis with 427 observations across 176 study sites in China. The goal was to quantify changes in the stocks of soil organic carbon (SOC) in mixed plantations compared with monocultures and to identify the predominant drivers for the stocks of SOC, including geological location, climatic factors, land use history, edaphic properties, plantation age, the inclusion of nitrogen-fixing trees, mixing proportion, and mixed plant types. The results showed that mixed plantations significantly increased the SOC stocks by 12% compared with monocultures, and the mixing proportion should not exceed 55% to produce higher SOC stocks in mixed plantations compared with monoculture. Additionally, mixed plantations in barren land are the most likely to increase the SOC stocks with limited water or low temperatures for growth. Additional measures instead of mixed plantations should be explored to increase SOC stocks in north, central, and northwest China. The data from this study demonstrated the spatiotemporal variability on the storage of SOC driven by mixed trees and has valuable implications for the establishment and management of afforestation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Orchard grass coverage has been widely adopted to increase fruit yield by improving soil fertility. However, the impact of the environment on the changes in soil organic carbon (SOC) stocks consecutive to orchard grass coverage remain poorly quantified at a large scale. The present study aimed to examine the responses of SOC stocks to grass coverage at a soil depth of 0-30 cm in orchards compared to clean tillage. A total of 342 observations across China from 139 peer-reviewed publications were subjected to meta-analysis. Aggregated boosted tree analysis was performed, evaluating the determinants of SOC stocks, such as plant traits (e.g., fruit tree type, grass type, orchard age, and grass age), edaphic variables (e.g., initial SOC and nitrogen concentration, soil pH, and soil clay content), climatic factors (e.g., mean annual precipitation (MAP) and mean annual temperature (MAT)), and management practices (e.g., grass source, grass growing mode, fertilization, grass mowing, placement of mowed residues, and irrigation). On average, orchard grass coverage significantly enhanced SOC stocks by 21.47% (percentage change) compared to clean tillage. Biotic and abiotic factors influenced this increase in SOC stocks following grass coverage in orchards to different extents. Grass age and soil clay content were the main determinants driving the variation in the SOC stocks following grass coverage in orchards. Thus, we propose an efficient way to optimize C sequestration in grass covered orchards, regarding plant traits, climatic factors, edaphic variables, and management practices. Longer than 12 months of surface grass coverage with cultivated grass species in mature deciduous fruit orchards (≥5 years) efficiently increased SOC stocks. This is particularly the case for acidic (pH < 6.5) soils with low C content (SOM < 15 g kg -1 ) in areas with suitable rainfall and temperature conditions (MAP ≥ 400 mm, MAT ≥ 10 °C). Collectively, this meta-analysis identified orchard grass coverage as a promising practice for significantly increasing SOC stocks at 0-30 cm across large geospatial locations in China., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier B.V.)

This study aimed to simulate oak and beech forest growth under various scenarios of climate change and to evaluate how the forest response depends on site properties and particularly on stand characteristics using the individual process-based model HETEROFOR. First, this model was evaluated on a wide range of site conditions. We used data from 36 long-term forest monitoring plots to initialize, calibrate, and evaluate HETEROFOR. This evaluation showed that HETEROFOR predicts individual tree radial growth and height increment reasonably well under different growing conditions when evaluated on independent sites. In our simulations under constant CO 2 concentration ([CO 2 ] cst ) for the 2071-2100 period, climate change induced a moderate net primary production (NPP) gain in continental and mountainous zones and no change in the oceanic zone. The NPP changes were negatively affected by air temperature during the vegetation period and by the annual rainfall decrease. To a lower extent, they were influenced by soil extractable water reserve and stand characteristics. These NPP changes were positively affected by longer vegetation periods and negatively by drought for beech and larger autotrophic respiration costs for oak. For both species, the NPP gain was much larger with rising CO 2 concentration ([CO 2 ] var ) mainly due to the CO 2 fertilisation effect. Even if the species composition and structure had a limited influence on the forest response to climate change, they explained a large part of the NPP variability (44% and 34% for [CO 2 ] cst and [CO 2 ] var , respectively) compared to the climate change scenario (5% and 29%) and the inter-annual climate variability (20% and 16%). This gives the forester the possibility to act on the productivity of broadleaved forests and prepare them for possible adverse effects of climate change by reinforcing their resilience., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Mathematical models of different types and data intensities are highly used by researchers, epidemiologists, and national authorities to explore the inherently unpredictable progression of COVID-19, including the effects of different non-pharmaceutical interventions. Regardless of model complexity, forecasts of future COVID-19 infections, deaths and hospitalization are associated with large uncertainties, and critically depend on the quality of the training data, and in particular how well the recorded national or regional numbers of infections, deaths and recoveries reflect the the actual situation. In turn, this depends on, e.g., local test and abatement strategies, treatment capacities and available technologies. Other influencing factors including temperature and humidity, which are suggested by several authors to affect the spread of COVID-19 in some countries, are generally only considered by the most complex models and further serve to inflate the uncertainty. Here we use comparative and retrospective analyses to illuminate the aggregated effect of these systematic biases on ensemble-based model forecasts. We compare the actual progression of active infections across ten of the most affected countries in the world until late November 2020 with "re-forecasts" produced by two of the most commonly used model types: (i) a compartment-type, susceptible-infected-removed (SIR) model; and (ii) a statistical (Holt-Winters) time series model. We specifically examine the sensitivity of the model parameters, estimated systematically from different subsets of the data and thereby different time windows, to illustrate the associated implications for short- to medium-term forecasting and for probabilistic projections based on (single) model ensembles as inspired by, e.g., weather forecasting and climate research. Our findings portray considerable variations in forecasting skill in between the ten countries and demonstrate that individual model predictions are highly sensitive to parameter assumptions. Significant skill is generally only confirmed for short-term forecasts (up to a few weeks) with some variation across locations and periods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Human-induced climate and land-use changes are important factors influencing global insect diversity. Nevertheless, the influence of weather on biodiversity is still relatively rarely studied. Grassland insects may be the taxon that is most affected by changing weather. We focused on the influence of weather and land-use management on butterflies in hayed meadows in the Czech Republic. During two consecutive years (2019-2020), we studied nearly 300 independent meadows. The abundance of butterflies was more influenced by the weather than their species richness. We observed positive and mainly linear effects of increasing vegetation temperatures. One very influential variable was the light intensity, which had a nonlinear effect that promoted butterflies under direct sunlight. The humidity had mainly moderate, nonlinear effects. Surprisingly, the wind had only a small effect. We observed important effects of the flowering intensity and vegetation height on the butterfly species richness and abundance regarding land use. Marginal woody vegetation cover had a positive effect on the butterfly abundance, and management had little effect. We concluded that weather and land use had important effects on butterflies. Based on our research, we recommended the reconsideration of scientific studies and monitoring programs for insects concerning the temperature threshold (≥ 25 °C) and the consideration of light intensity as an important factor. Applying a detailed approach to measuring the flowering intensity is likely unnecessary, while meadow land-use parameters appear to be necessary for insect populations., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Iron/copper bimetallic nanoparticles based sludge biochar (Fe/Cu-SBC) was prepared by using a modified co-precipitation route. The Fe/Cu-SBC system prepared was subsequently applied to activate periodate (IO 4 - ) to degrade diclofenac sodium (DCF) by using UV light at room temperature (25 °C). The physicochemical properties of both SBC and Fe/Cu-SBC such as morphology, physical properties, crystal structures and functional groups were examined. The type and number of surface functional groups were found to be increased and the catalytic performance was improved by the modification of Fe/Cu bimetallic nanoparticles. The influence of various parameters to evaluate the catalytic efficiency such as periodate (PI) concentration, dosage of catalysts, UV power, initial pH and coexisting anions were investigated. Under the optimized conditions (pH 6.9, UV-power 60 W, PI concentration of 5 mM and 0.1 g Fe/Cu-SBC), it was observed that 99.7% of DCF was degraded with a pseudo-first-order kinetics reaction constant 9.39 × 10 -2 min -1 . The radical scavenging experiments showed that IO 3 radicals were the predominantly reactive oxidants in the Fe/Cu-SBC/UV system. Therefore, this investigation provides a feasible alternative for the degradation of PPCPs in wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Given the high ozone concentrations observed in the Mediterranean region during summer, it is crucial to extend our knowledge on the potential ozone impacts on forest health with in situ studies, especially to protect typical endemic forests of the Mediterranean basin. This study is focused on ozone measurements and exposures over the Eastern Adriatic coast and on the calculation of different O 3 metrics, i.e., accumulated exposure AOT40 (AOT40 dir , AOT40 ICP , AOT40 pheno ) and stomatal O 3 fluxes with an hourly threshold of uptake (Y) to represent the detoxification capacity of trees (PODY, with Y = 0, 1, 2 nmol O 3 m -2 s -1 ) used for forest protection. Finally, we provide an assessment of the relationships between the forest response indicators and environmental variables. Passive ozone measurements and monitoring of forest health indicators, namely growth and crown defoliation, were performed for Quercus ilex, Quercus pubescens, Pinus halepensis, and Pinus nigra forests. Results showed that, for all the analysed species, ozone levels were close to reached the upper plausibility limits for passive monitoring of air quality at forest sites (100 ppb), with the highest values found on P. halepensis in the summer period. O 3 metrics based on exposure were found to be higher in pine plots than in oak plots, while the highest values of uptake-based metrics were found on P. nigra. Regarding relationships between environmental variables and forest-health response indicators, the crown defoliation was significantly correlated with the soil water content at various depth while the tree growth was correlated with the different O 3 metrics. The most important predictors affecting tree growth of Q. pubescens and Q. ilex were AOT40 pheno and AOT40 dir and POD0 for P. nigra., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In Mediterranean areas where drought-induced forest dieback and tree mortality have been widely reported, it is still under debate how the likely risks of climate change will affect tree growth and consequently forest productivity. Increasing tree mortality has been associated not only to increased drought, but also to a lack of management in many dense pine forests and plantations, where warming may intensify tree-to-tree competition for soil water. This emphasizes the need of using silviculture to adapt dense stands of Mediterranean pine reforestations to warmer and drier conditions. Here we combined dendrochronology and C and O isotope analyses of wood in two Aleppo pine (Pinus halepensis) plantations, growing under semiarid conditions and experimentally thinned at high and moderate intensities along with control. The main aim was to understand the responses of radial growth and water use efficiency (WUEi) to different thinning intensities, and to analyze the effectiveness of thinning to enhance post-drought growth resilience. Thinning had a positive effect on growth, produced an increase of δ 18 O, reduced growth sensitivity to drought and decreased WUEi, suggesting a reduction of drought stress. These results were consistent across sites, and were significant even 20 years after the intervention took place. Considering the climate effects on growth through the SPEI drought index to calculate resistance and recovery indices, an increase of resistance after thinning was observed. We conclude that high thinning intensity (50% of basal area removed) is a useful silviculture intervention on Mediterranean Aleppo pine plantations that enhances their growth, and makes them less dependent on harsh climatic conditions, improving their resilience against drought and consequently making them better adapted to more unfavourable conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This study was conducted to understand how different wetland vegetation-land use types influenced the storage and stability of soil organic carbon (SOC) in surface soils. We determined the concentration and chemical composition of SOC in both density (including light fraction organic carbon (LFOC) and heavy fraction organic carbon (HFOC)) and particle size fractions (including <2 μm, 2-63 μm, 63-200 μm and 200-2000 μm) in four wetland land use types covered with different vegetation: lake-sedge, reed, willow and poplar wetlands. Results showed that the concentrations and stock of SOC and LFOC in willow and poplar wetlands were significantly higher than those in lake-sedge and reed. However, a higher proportion of alkyl-C and a lower proportion of O-alkyl-C were observed in lake-sedge and reed wetlands than in willow and poplar, suggesting that accumulated C in willow and poplar wetlands was less stable than that in lake-sedge and reed. For all particle-size fractions except the silt (2-63 μm), the SOC concentrations were highest in willow and lowest in reed wetland surface soils, while their alkyl-C/O-alkyl-C (A/O-A) and hydrophobic-C/hydrophilic-C ratios progressively decreased from lake-sedge and reed wetland surface soils to poplar and willow surface soils. Moreover, the ratios of A/O-A and hydrophobic-C/hydrophilic-C in surface soils generally decreased with increasing concentrations of SOC in particle-size fractions, with these stability indexes being lowest in the largest particle-size fraction. These results indicate that the wetland vegetation-land use types that could incorporate more C into finer particle-size fractions had a greater potential for sequestering more stable C in such wetland ecosystems. Different wetland vegetation-land use types resulted in significant changes in the concentration and chemical structure of SOC, which could affect soil C sequestration and dynamics, C cycling in wetland ecosystems. Although both willow and poplar forests could increase SOC stock, the stability of SOC in willow wetland was higher. Therefore, on balance (stock and stability) the land use of wetland for willow forest could be a more promising way for enhancing soil C sequestration in wetlands., Competing Interests: Declaration of competing interest The authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This paper applies a social metabolism framework and energy flow analysis for evaluating agroecosystem and land use transitions in food-energy-water systems using the Upper Snake River Basin (USBR), Idaho, USA as a case-study. The study area is one of the primary agricultural regions of the State of Idaho. Dairy products are the primary agricultural outputs of the region; therefore, we modified a biomass accounting framework to explicitly incorporate the role of manure in the agroecosystem. Despite the increase of cropland between 2002 and 2012 in the basin, a decrease in energy input was observed for crop production. An increase in the industrial energy inputs for dairy production, on the other hand, showed that the basin is a clear example of a metabolic industrialized farm system - an example of land use intensification. We compare the energy return on investments (EROIs) as an indicator of agroecosystem transition for both crop and dairy production during the period 2002 to 2012. Contrary to our expectations, the analysis suggests that livestock production is a relatively energy efficient process in land management in the basin. This is due to the reuse of nutrient by-products from livestock as well as the refuse and residues from crop farming. At the same time, the findings provide insights on the percentage of manure to be reinvested as compost that would improve energy production efficiency. However, the reuse of manure, as it is managed in the basin, may have a negative implication on the nutrient balance of the agroecosystem that needs further investigation. Nonetheless, there is market potential for the reuse and reinvestment of biomass to make energy production in the basin more efficient., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Agricultural and forestry activities can affect soil organic carbon (SOC) levels and CO 2 emissions from terrestrial ecosystems due to land use changes. In Northeast Himalayas, studies on the effects of forest conversion to temporary agricultural lands (jhum) on the loss of SOC and soil quality degradation have received the attention of policy makers and scientific research. Presently, local communities are now oriented towards the settled plantations systems with modern cash crops such as tea and rubber, that could act as potential SOC sinks. However, no information on SOC dynamics and simulation studies after land-use change from temporary agricultural lands (jhum) to settled cultivations and under climate change (CC) conditions are available for the Meghalaya state. Applying the RothC model, we focused on four different scenarios including the conversion from jhum to settled cultivation (rubber plantations and tea gardens), as well as continuous jhum cultivation and jhum to jhum with a period of secondary succession. Simulations under CC conditions indicated that SOC stocks significantly increased by 1.20 t C ha -1  yr -1 in tea gardens compared to rubber and jhum scenarios. Conversely, SOC stocks slightly decreased by 0.07 t C ha -1  yr -1 in rubber plantations, while the regrowth of a natural vegetation cover as secondary succession following the abandonment of the jhum fields, showed a lower SOC decrease (0.18 t C ha -1  yr -1 ) compared to the continuous jhum cultivation (0.24 t C ha -1  yr -1 ). Thus, for CC mitigation in a policy perspective, tea gardens could represent the best land use to store increasing amounts of SOC in the long-term perspective and optimize farmers' incomes, while in rubber plantations SOC storage is limited in time. Jhum cultivation can benefit in terms of productivity and profitability by extending the duration of the secondary succession period., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Enriched planting of native tree species in monoculture plantation forests is a commonly recommended forest practice. However, its effect on various ecological processes is generally lacking. Here, we carried out an experiment in a 16-year-old Eucalyptus plantation in South China to assess the effects of enriched planting of native tree species on surface water, soil erosion and nutrient losses. Two treatments were conducted in 2008: (1) enriched planting of native broadleaved tree species with uniform thinning of 60% of Eucalyptus trees (TEP); and (2) enriched planting of native broadleaved tree species without thinning (NEP). The original Eucalyptus plantation stands was used as the control (CK). Runoff plots (total n=9, 3 for each treatment or CK) were established in 2009, and surface water flow, sediment, nitrogen (N) and phosphorus (P) losses were monitored from major rainfall events in 2010-2012. Results showed that enriched planting in Eucalyptus plantation significantly reduced surface water flow and soil erosion. Compared with CK, TEP and NEP reduced annual surface water flow by 29-43% and 11-16%, and reduced annual soil erosion by 38-54% and 20-33% throughout the study period, respectively. TEP and NEP had significantly lower annual mean concentrations of N and P in surface water. Compared with CK, TEP reduced annual N and P losses through surface water by 42-60% and 44-64%, respectively, while NEP reduced them by 25-28% and 24-34%, respectively. N and P losses were significantly related to surface water flow. Between the two treatments, TEP was better for retaining water and soil, and for preventing nutrient loss. These results clearly demonstrated that the enriched planting of native tree species effectively retained surface water and nutrients., (Copyright © 2019. Published by Elsevier B.V.)

Larch (Larix sp.) tree is a critical species for the future afforestation in Northeast Asia. The impacts of elevated concentrations of ground-level ozone (O 3 ) and nitrogen (N) deposition are raising concerns. However, knowledge of the combined effects of elevated O 3 and N loading are still limited. We investigated whether nitrogen loading mitigates the negative impacts of ozone on two larch species: the Japanese larch (L. kaempferi) and its hybrid larch F 1 (L. gmelinii var. japonica × L. kaempferi) or not. We used open-top cambers and compared responses of the larch seedlings. Results showed the N loading mitigated the negative effects of O 3 on Japanese larch. However, in hybrid larch F 1 , N loading did not mitigate O 3 -induced inhibition of growth and photosynthetic capacity. Mitigation effect of N loading on negative O 3 impacts may vary between the two Larix spp., Hybrid larch F 1 could be more affected by the combined effects of O 3 and N loading due to its higher growth response to N loading. Elevated O 3 also reduced leaf nitrogen/phosphorus (N/P) ratio by elevated O 3 , with significant effects in hybrid larch F 1 , particularly under N loading. In the present study, leaf N/P ratio was utilized to validate the hypothesis that a positive effect of N loading may be observed if O 3 does not induce P limitation in Larix spp. We demonstrated a potential leaf N/P ratio function, which could reflect responses to O 3 and N loading in hybrid larch F 1 ., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Under predicted climate change, native silver fir (Abies alba) and European beech (Fagus sylvatica) are the most likely replacement species for the Norway spruce (Picea abies) monocultures planted across large parts of continental Europe. Our current understanding of the adaptation potential of fir-beech mixed forests to climate change is limited because long-term responses of the two species to environmental changes have not yet been comprehensively quantified. We compiled and analysed tree-ring width (TRW) series from 2855 dominant, co-dominant, sub-dominant and suppressed fir and beech trees sampled in 17 managed and unmanaged mixed beech-fir forest sites across Continental Europe, including Bosnia and Herzegovina, Germany, Italy, Romania and Slovakia. Dendroecological techniques that combine various detrending methods were used to investigate variation in radial growth of co-occurring fir and beech trees. Coincidental with peak SO 2 emissions, the growth of silver fir declined between 1950 and 1980 at most sites, whereas beech growth increased during this period. Correspondent to a significant warming trend from 1990-2010, average beech growth declined, but silver fir growth increased. Long-term growth patterns and growth-climate sensitivity of fir and beech trees did not significantly differ between managed and unmanaged forests. Multi-decadal changes in the growth rate of all vertical tree classes were similar. In contrast to previous indications of limited drought susceptibility of beech mixed stands, this study suggests that the mixture of tree species in forest stands does not necessarily prevent growth depressions induced by long-term environmental change. Our results further imply that forest management does not necessarily alter their sensitivity to environmental changes., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

Fecal lead (Pb) levels were investigated in the threatened European population of the Lesser White-fronted Goose (LWfG, Anser erythropus) and of the non-threatened Greater White-fronted Goose (GWfG, Anser albifrons) wintering in two wetland areas in northern Greece in order to assess the potential risk from Pb exposure. Fecal, soil and food plant samples were analyzed. Levels of Pb were normalized using Al concentrations in order to separate the effect of possible ingestion of Pb shot from that of soil or sediment accidentally ingested with food. All concentrations are expressed on a dry weight basis. Geometric means of Pb content in the feces of LWfG were 6.24 mg/kg at Evros Delta and 7.34 mg/kg at Lake Kerkini (maximum values of 28.61 mg/kg and 36.68 mg/kg, respectively); for fecal samples of GWfG geometric means were 2.39 mg/kg at Evros Delta and 6.90 mg/kg at Kerkini (corresponding maximum values of 25.09 mg/kg and 42.26 mg/kg). Soil Pb was in the range of 5.2-60.2mg/kg (geometric mean = 22.6 mg/kg) for the Evros Delta and between 13.4 and 64.9 mg/kg (geometric mean=28.1mg/kg) for Kerkini. A general linear model fitted to the data showed that Pb levels were very closely dependent on Al levels in the feces from both species and at both sites indicating soil or sediment were the only significant source of Pb; species and site, as well as their interaction, were not statistically significant factors. For both species and at both sites exposure to Pb was evidently very mild and the observed levels of Pb were well below the proposed thresholds for lethal or sublethal effects of Pb poisoning. Soil ingestion appeared to gradually increase from October to December for LWfG at Kerkini, corresponding to a gradual depletion of their food source., (Copyright © 2015. Published by Elsevier B.V.)

Human induced land use changes negatively impact the viability of many wildlife species through habitat modifications and mortality, while some species seem to benefit from it. Roe deer (Capreolus capreolus), a wide spread ungulate increased both its abundance and range throughout Europe. This pattern is also reflected in the increasing hunting bags over the last 40 years. Such a development raises questions about the relationship between human hunting and population dynamics and, in particular, about the potential of human hunting to control related populations. We analysed and reconstructed annual hunting bags of roe deer for three federal states of northern Germany, Brandenburg, Lower Saxony and Mecklenburg West Pomerania for the years 1972 to 2011. Since 1992 the hunting bags from these three states are significantly higher than those reported for the years 1972-1991. Our reconstruction takes into consideration effects of climate variability, expressed by inter-annual changes in the North Atlantic Oscillation and impacts from rapeseed and wheat cultivation. We found that severe winters, which are indicated by negative values of the North Atlantic Oscillation during the months December-March, directly, or with a time lag of two years affect the number of deer shot. In contrast, an increase in the area used for rapeseed cultivation coincides with higher numbers of roe deer shot, with respect to the overall mean value. Consequently, we recommend that wildlife management addresses changes in large scale processes including land use pattern and climate variability., (© 2013.)

Observations of increased water colour have been made in lakes and rivers all across the northern mid-latitudes of Europe and North America, particularly during the last 10-20 yr. This water browning or brownification has been attributed to the increased organic carbon concentrations due to climate change and decreased acid atmospheric deposition. Given that iron (Fe) may also increase water colour, the contribution of Fe to water brownification has received small attention. Our aim was to study the temporal trends of Fe in forested headwater catchments in eastern Finland, where an increasing air temperature and total organic carbon (TOC) trend had been observed in an earlier study. We found a statistically significant increasing trend also in stream water Fe concentrations and a strong correlation between the trends of TOC and Fe. The average increase in TOC and Fe concentrations between 1995 and 2006 was 0.5 mg l(-1) yr(-1) (2.5%), and 34.6 μ gl(-1) yr(-1) (3.5%), respectively. These results indicate that the increased water colour or brownification in Northern Europe may not only be due to increased concentrations of organic matter but also increased concentrations of Fe. The change in precipitation and temperature conditions, particularly during late autumn and early winter periods, appeared to be the main environmental factor behind increasing Fe trends. The strong correlation between the trends of Fe and TOC indicated that the increased Fe-organic matter complexation is the mechanism behind increasing Fe trends, but further research is needed to assess the chemical forms of increased Fe that coupled with increased TOC concentrations would enhance water brownification., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Temporal trends in stream water total organic carbon (TOC) concentration and export were studied in 8 forested headwater catchments situated in eastern Finland. The Seasonal Kendall test was conducted to identify the trends and a mixed model regression analysis was used to describe how catchment characteristics and hydrometeorological variables (e.g. precipitation, air and stream water temperatures, and atmospheric deposition) related to the variation in the concentration and export of stream water TOC. The 8 catchments varied in size from 29 to 494 ha and in the proportion of peatland they contained, from 8 to 70%. Runoff and TOC concentration were monitored for 15-29 years (1979-2006). Trends and variation in TOC levels were analysed from annual and seasonal time series. Mean annual TOC concentration increased significantly in seven of the eight catchments. The trends were the strongest in spring and most apparent during the last decade of the study period. The slopes of the trends were generally smaller than the variation in TOC concentration between years and seasons and between catchments. The annual TOC export showed no clear trends and values were largely determined by the temporal variability in runoff. Annual runoff showed a decreasing trend in two of the eight catchments. Mean annual air and stream water temperatures showed increasing trends, most clearly seen in the summer and autumn series. According to our modeling results, stream water temperature, precipitation and peatland percentage were the most important variables explaining annual and most seasonal TOC concentrations. The atmospheric deposition of SO4, NH4, and NO3 decreased significantly over the study period, but no significant link with TOC concentration was found. Precipitation was the main hydrometeorological driver of the TOC export. We concluded that stream water TOC concentrations and exports are mainly driven by catchment characteristics and hydrometeorological factors rather than trends in atmospheric acid deposition.

We studied the chemical changes in forest soil and the effects on Scots pine trees caused by continuous sprinkling infiltration over a period of two years, followed by a recovery period of two years. Infiltration increased the water input onto the forest soil by a factor of approximately 1000. After one year of infiltration, the pH of the organic layer had risen from about 4.0 to 6.7. The NH(4)-N concentration in the organic layer increased, most probably due to the NH(4) ions in the infiltration water, as the net N mineralization rate did not increase. Sprinkling infiltration initiated nitrification in the mineral soil. Macronutrient concentrations generally increased in the organic layer and mineral soil. An exception, however, was the concentration of extractable phosphorus, which decreased strongly during the infiltration period and did not show a recovery within two years. The NO(3)-N and K concentrations had reverted back to their initial level during the two-year recovery period, while the concentrations of Ca, Mg and NH(4)-N were still elevated. Nutrient concentrations in the pine needles increased on the infiltrated plots. However, the needle P concentration increased, despite the decrease in plant-available P in the soil. Despite the increase in the nutrient status, there were some visible signs of chlorosis in the current-year needles after two years of infiltration. The radial growth of the pines more than doubled on the infiltrated plots, which suggests that the very large increase in the water input onto the forest floor had no adverse effect on the functioning of the trees. However, a monitoring period of four years is not sufficient for detecting potential long term detrimental effects on forest trees.

We report on weekly aluminum (Al) concentration measurements in soil water from forested catchments monitored throughout Norway since 1986. Originating in acidification research, and thus accompanied by many other chemical variables, they constitute a comprehensive data set suited for analysis of short- as well as long-term variations in a geographic perspective. The Al time series at 21 sites are characterized by high temporal variability, seasonal behavior, and episodic events with peak values in the range 200-800 micromol/l, mostly caused by sea salts blown inland in storms, with a subsequent release of Al after cation exchange. Despite a clear south-north gradient in possible acidification over Norway, we found no indication of such south-north trends in Al chemistry, neither in mean values, maximum values, nor time trends. We identified two main drivers for variation in Al concentrations. The first one was sea salts, where Al was released to the soil solution after cation exchange. The second driver was high production of DOC, where Al was driven into the soil solution by complexation with DOC. There appears to be little risk for aluminum toxicity to trees in Norwegian forests. Except during occasional episodes, aluminum concentrations generally lay far below the supposed threshold values for toxic effects on Norway spruce, Scots pine and birch. Much dissolved aluminum was non-labile, and thus relatively non-toxic. Although the Ca2+/labile Al ratio was often below 1.0, considerable doubt exists as to the applicability of this variable in the field.

Macronutrient (N, P, K, Mg, S, Ca), heavy metal (Fe, Zn, Mn, Cu, Ni, Cd, Pb) and Al concentrations in understorey bryophytes, lichens and vascular plant species growing in Scots pine forests at four distances from the Harjavalta Cu-Ni smelter (0.5, 2, 4 and 8 km) were compared to those at two background sites in Finland. The aim was to study the relationship between element accumulation and the distribution of the species along a pollution gradient. Elevated sulfur, nitrogen and heavy metal concentrations were found in all species groups near the pollution source. Macronutrient concentrations tended to decrease in the order: vascular plants>bryophytes>lichens, when all the species groups grew on the same plot. Heavy metal concentrations (except Mn) were the highest in bryophytes, followed by lichens, and were the lowest in vascular plants. In general, vascular plants, being capable of restricting the uptake of toxic elements, grew closer to the smelter than lichens, while bryophytes began to increase in the understorey vegetation at further distances from the smelter. A pioneer moss (Pohlia nutans) was an exception, because it accumulated considerably higher amounts of Cu and Ni than the other species and still survived close to the smelter. The abundance of most of the species decreased with increasing Cu and Ni concentrations in their tissues. Cetraria islandica, instead, showed a positive relationship between the abundance and Cu, Ni and S concentrations of the thallus. It is probable that, in addition to heavy metals, sporadically high SO(2) emissions have also affected the distribution of the plant species.

High levels of nitrogen deposition measured in throughfall fluxes in 2002, reaching 38 kg ha(-1) year(-1), affected the biogeochemical cycle of N in an Aleppo pine (Pinus halepensis) stand situated in Athens, the capital of Greece. The N fluxes in bulk deposition were far lower than those in throughfall indicating high levels of dry deposition in the city of Athens. The amounts of N in litterfall and those stored in the forest floor and mineral soil were not high, while the mean residence time of N in the forest floor, derived from fluxes equations, decreased considerably due to the high levels of N fluxes in throughfall deposition. Nitrogen concentration in needle tissues was high and this resulted in a high ratio of N/Zn. Zinc availability was low due to the alkaline nature of soil in the study area. Fast N cycling may affect the living status of Aleppo pine, which is an oligotrophic plant species capable of occupying poor soil sites. Nitrogen eutrophication may adversely affect forests grown on calcareous soils by developing nutrition imbalances between N and micronutrients, the solubility of which depends on soil pH values.

Heavy metal deposition and changes in the deposition patterns were investigated on the basis of surveys carried out in 1985, 1990, 1995 and 2000. The concentrations of 10 elements (Cd, Cr, Cu, Fe, Ni, Pb, Zn and V; and As and Hg since 1995) were determined on moss (Hylocomium splendens, Pleurozium schreberi) samples collected from the same permanent sample plots in each survey. The heavy metal concentrations, apart from those in southernmost Finland and close to a number of major emission sources, were relatively low. The mean concentrations of all the heavy metals decreased during the period covered by the surveys. The metals that showed the strongest decrease in concentration since 1985 were Pb (78%), V (70%) and Cd (67%). The concentrations of the other heavy metals decreased by 16-34%. The concentrations of Cr, Cu and Ni were clearly associated with local emission point sources and changes in emission levels. The concentrations of As and Hg, which were measured for the first time during the 1995 survey, decreased on the average by 26% and 10%, respectively.

Major nutrients and acidity were studied at six plots in four Integrated Monitoring catchments in Finland, located along a south-north deposition gradient. The quality and quantity of bulk precipitation, throughfall, soil water, and litterfall were monitored during the period 1989-1997. The results showed a marked decline in SO4 and H+ concentrations overall. Trends in throughfall ANC values were positive, while those in soil water were mostly negative. The increase in throughfall ANC values indicates recovery from acid deposition. The adsorption of base cations and release of organic acids was implicated in the decrease in soil water ANC trends. For all variables, the changes tended to be the greatest in the most southerly catchment, which received the most deposition loads. Mass balance budgets showed that total deposition inputs were greater than soil leaching outputs (at 40 cm) for NO3, NH4 and SO4, and were attributed to nutrient uptake and cycling processes. In contrast, for Ca, Mg, K and Na, and S (Valkea-Kotinen3 and Vuoskojärvi2 plots only), inputs were less than outputs, indicating net leaching. Throughfall + litterfall inputs to the forest floor showed that the organic layer is particularly important in the retention of Ca, Mg and N. Sulfur was retained in the lower soil layers, and attributed to Al and Fe hydroxide adsorption in the B horizon.

The accumulation of selected trace elements (Cu, Ni, Zn, Pb, As) in the surface peat layer of an ombrotrophic bog 2.4 km from a Cu-Ni smelter at Harjavalta, Finland was studied using a peat core. A reference core was taken from an ombrotrophic bog at a background site, Hietajärvi, in eastern Finland. Element concentrations were analysed from 1-cm slices and enrichment factors (EF) were calculated. The enrichment factors of both Cu and Ni in the Harjavalta peat bog are extremely high compared to the Hietajärvi site. However, only the 6-cm surface peat Pb values are higher in Harjavalta compared to Hietajärvi. Precipitation was collected during 1992-1996, in the vicinity of the Harjavalta smelter, in order to estimate the current atmospheric deposition load. Comparison between the precipitation and peat data reveals that at Harjavalta the surface peat is relatively much more polluted than the current precipitation. The variation in EF of the Harjavalta peat core with respect to depth shows two patterns: Cu and Pb are similar, as are Ni, Zn and As. The vertical gradient in Harjavalta Cu EF suggests that Cu supplied to the peat by atmospheric deposition is very well preserved by the bog.