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Rivers of tropical islands formed by volcanic eruptions experience unpredictable and heavy rainfall and are characterised by irregular topography. During the 2019 and 2020 low-water season, we investigated the responses of benthic macroinvertebrate assemblages to variations in local environmental conditions in four rivers located in areas of different rainfall intensity. We found that changes in local environmental conditions associated with lower rainfall intensity reduced abundance and taxonomic richness and modified taxonomic composition but did not impact the balance of functional feeding groups of macroinvertebrate communities amongst streams, except for piercer herbivores. Heterotrophy associated with substrate instability and autotrophy with a more stable substrate co-occurred in semi-arid climate rivers. In contrast, a change from heterotrophy upstream to autotrophy and substrate stability downstream was apparent in the two humid rivers studied. Surrogates of stream ecosystem function revealed a very low ratio of coarse to fine particulate organic matter related to the quasi-absence of shredders in these streams and suggested a low allochthonous input contribution, which could be the result of the 5% decline in forest cover over the two past decades. [ABSTRACT FROM AUTHOR]

Excessive anthropogenic nitrogen fixation alters the nitrogen cycle and increases nitrogen deposition, leading to nitrogen saturation, which in turns leads to forest decline and nitrate leaching into stream waters. Kureha Hill in Toyama Prefecture, Japan, is considered to be in nitrogen saturation, since many streams have contained high concentrations of nitrate for more than 20 years. In this study, the latest status of nitrogen saturation was verified by comparing most recent data with 20 years observational data, focusing on various indicators of nitrogen saturation, such as stream water quality, nitrogen budget of the watershed, and soil nitrification and mineralization potential. Both the nitrogen deposition on the Hyakumakidani watershed on Kureha Hill and the amount of nitrate leaching to the stream tended to decrease. The reduction in nitrate leaching could be attributed to the reduction in nitrogen deposition and other factors, such as nitrogen pools in the soil. Despite the recent decline in nitrate concentration of the Hyakumakidani stream, the pH level has remained unchanged. This may be due to decreased concentrations of sulfate and acid neutralizing capacity (ANC). The C/N ratio of the soil ranged from 12 to 18 from 2000 to 2023, which was lower than the nitrogen saturation threshold of 25. The net nitrification rate and net mineralization rate showed no significant changes between 2002 and 2023, indicating that the potential to produce nitrate has been unchanged. Similar values in net nitrification and net nitrogen mineralization rates reflected that the Hyakumakidani watershed remained in Stage‐3 nitrogen saturation. [ABSTRACT FROM AUTHOR]

Introduction: Since 1990, there has been a global decline in forest areas. Between 2010 and 2020, the greatest annual net loss of forests was on the African continent. Despite South African indigenous forests and trees being protected under the National Forests Act of 1998 (Act No. 84 of 1998), the country has also shown an increased annual net loss of forests. Although the Vhembe District Municipality in South Africa has lost forest owing to humaninduced deforestation and other land use activities, sacred forests have not been affected. According to traditional beliefs, exploitation of such indigenous patches of sacred forests is taboo. This study aims to explore the role of taboos in the protection of the remaining patches of sacred forest. Methods: The study relies on data collected between December 2022 and December 2023. Semi-structured interviewswere conductedwith key informants (n = 61) and local communities in Tshidzivhe and Duthuni villages (n = 60). Observations were used as a further data collection tool. The interview questions were prepared to assess the role of taboos in the protection and management of sacred forests. Data collected through interviews were analysed using thematic content analysis, while field observations helped to corroborate the results from the interviews. Results and discussion: The study identified two main taboos - one that restricts entry into the sacred forests (i.e. preventing entry into the sacred forests, and harvesting, hunting and hiking in these areas), and another that prohibits noise or activities that disrespect sacred forests. The study found that believers and nonbelievers alike, for fear of retribution by the spirits, still obey these taboos and their relatedmyths. This has allowed these areas to develop dense stands of closed-canopy evergreen forest that support more diverse flora and fauna than found in surrounding areas. Although sacred forests are not meant for biodiversity conservation, they offer opportunities to be integrated into global conservation targets of "30x30" and "Half-Earth" by 2030. They also offer the opportunity of serving as carbon sinks which is key to climate change mitigation. Recommendations for protecting sacred forests and associated taboos are drawn up based on these results. [ABSTRACT FROM AUTHOR]

Approximately one quarter of the earth's population directly harvests natural resources to meet their daily needs. These individuals are disproportionately required to alter their behaviors in response to increasing climatic variability and global biodiversity loss. Much of the ever‐ambitious global conservation agenda relies on the voluntary uptake of conservation behaviors in such populations. Thus, it is critical to understand how such individuals perceive environmental change and use conservation practices as a tool to protect their well‐being. We developed a participatory mapping activity to elicit spatially explicit perceptions of forest change and its drivers across 43 mangrove‐dependent communities in Pemba, Tanzania. We administered this activity along with a questionnaire regarding conservation preferences and behaviors to 423 individuals across those 43 communities. We analyzed these data with a set of Bayesian hierarchical statistical models. Perceived cover loss in 50% of a community's mangrove area drove individuals to decrease proposed limits on fuelwood bundles from 2.74 (forest perceived as intact) to 2.37 if participants believed resultant gains in mangrove cover would not be stolen by outsiders. Conversely, individuals who believed their community mangrove forests were at high risk of theft loosened their proposed harvest limits from 1.26 to 2.75 bundles of fuelwood in response to the same perceived forest decline. High rates of intergroup competition and mangrove loss were thus driving a self‐reinforcing increase in unsustainable harvesting preferences in community forests in this system. This finding demonstrates a mechanism by which increasing environmental decline may cause communities to forgo conservation practices, rather than adopt them, as is often assumed in much community‐based conservation planning. However, we also found that when effective boundaries were present, individuals were willing to limit their own harvests to stem such perceived decline. [ABSTRACT FROM AUTHOR]

The cause of Paget's disease of bone (PDB) is unknown. It emerged as a distinct entity in Britain in the late nineteenth century when it was prevalent, and florid presentation not uncommon. Epidemiological surveys in the 1970s showed that Britain had a substantially higher prevalence of PDB than any other country. Studies in the late twentieth and early twenty-first centuries have documented an unexplained change in presentation, with a greatly reduced prevalence and less severe disease than formerly. The emergence of PDB in Britain coincided with rapid industrialization which, in turn, was driven by the use of coal for energy. In the home, bituminous coal was customarily burnt on an open hearth for heating. Using data on coal production, population size, and estimates of domestic use, the estimated exposure to domestic coal burning rose threefold in Britain during the nineteenth century and began to fall after 1900. This pattern fits well with the decline in PDB documented from death certification and prevalence surveys. Colonists moving from Britain to North America, Australia and New Zealand established coal mines and also used coal for domestic heating. PDB was found in these settler populations, but was largely absent from people indigenous to these lands. In all parts of the world PDB prevalence has fallen as the burning of coal in open hearths for domestic heating has reduced. The nature of the putative factor in coal that could initiate PDB is unknown, but possible candidates include both organic and inorganic constituents of bituminous coal. [ABSTRACT FROM AUTHOR]

This study investigates the spatial urban growth patterns of cities along the Democratic Republic of the Congo (DRC) and Zambia border, a region of significant economic importance characterized by cross-border trade. This activity has led to rapid but unplanned urban growth. The objective is to quantify the spatial expansion of Congolese cities (Kipushi, Kasumbalesa, Mokambo, and Sakania) bordering Zambia and to evaluate associated landscape changes. The methodology of this study includes the supervised classification of Landsat images with a spatial resolution of 30 m for the years 1990, 2000, 2010, and 2023. This classification was validated using field data. Subsequently, landscape metrics such as class area, patch number, Shannon diversity index, disturbance index, urban expansion intensity index, largest patch index, and mean Euclidean distance were calculated for each city and each date. The results reveal substantial landscape transformations in the border cities between 1990 and 2023. These changes are primarily driven by rapid urban expansion, particularly pronounced in Kasumbalesa. Between 1990 and 2023, forest cover declined from 70% to less than 15% in Kipushi, from 80% to 10% in Kasumbalesa, from 90% to 30% in Mokambo, and from 80% to 15% in Sakania. This forest cover loss is accompanied by an increase in landscape element diversity, as indicated by the Shannon diversity index, except in Kipushi, suggesting a transition towards more heterogeneous landscapes. In these border cities, landscape dynamics are also characterized by the expansion of agriculture and savannas, highlighted by an increase in the disturbance index. Analysis of spatial pattern changes shows that built-up areas, agriculture, and savannas exhibit trends of patch creation or aggregation, whereas forests are undergoing processes of dissection and patch attrition. Congolese cities bordering Zambia are undergoing substantial spatial changes propelled by intricate interactions between economic, demographic, and infrastructural factors. Our results underscore the need for sustainable development strategies to address urban sprawl through smart growth policies and mixed-use developments, mitigate deforestation via stricter land use regulations and reforestation projects, and enhance cross-border cooperation through joint environmental management and collaborative research initiatives. [ABSTRACT FROM AUTHOR]

Climate‐driven ecosystem shifts occur through turnover in the foundation species which structure the landscape. Therefore, to predict the fate of areas undergoing climate‐driven ecosystem shifts, one approach is to characterize ecological and evolutionary responses of foundation species along dynamic environmental gradients. One such gradient is the ecotone between tidal marshes and maritime forests in coastal areas of the US Mid‐Atlantic region where accelerated sea‐level rise and coastal storms of increased frequency and intensity are driving forest dieback and inland marsh migration. Mid‐Atlantic tidal marshes are structured by marsh grasses which act as foundation species, and these grasses exhibit trait variation across their distribution from established marsh interior to their inland migration front. We conducted a reciprocal transplant experiment with Spartina patens, a dominant high marsh grass and foundation species, between established populations in the high marsh and range edge populations in the forest understory at three Mid‐Atlantic sites. We monitored environmental conditions in marsh and forest understory habitats, measured plant traits (above‐ and belowground biomass, specific leaf area, leaf N and C concentrations) in transplanted and reference non‐transplanted individuals, and used microsatellite markers to determine the genetic identity of transplants to quantify clonality between habitats and sites. Individuals transplanted into the forest understory exhibited a plastic shift in resource allocation to aboveground structures associated with light acquisition, with shifts in transplants making them more morphologically similar to reference individuals sampled from the forest habitat. Clonal diversity and genetic distance among transplants were relatively high at two of three sites, but individuals at all sites exhibited trans‐habitat plasticity regardless of clonal diversity or a lack thereof. Individuals grown in the forest understory showed lower vegetative and reproductive fitness. Nevertheless, the trait plasticity exhibited by this species allowed individuals from the forest that were transplanted into the marsh to recoup significant biomass in only a single growing season. We predict high plasticity will facilitate the persistence of colonizing S. patens individuals under suboptimal forest shade conditions until forest dieback increases light availability, ultimately promoting continued inland migration of this foundation species under sea‐level rise. [ABSTRACT FROM AUTHOR]

Hydraulic failure due to xylem embolism has been identified as one of the main mechanisms involved in drought‐induced forest decline. Trees vulnerability to hydraulic failure depends on their hydraulic safety margin (HSM). While it has been shown that HSM globally converges between tree species and biomes, there is still limited knowledge regarding how HSM can adjust locally to varying drought conditions within species. In this study, we relied on three long‐term partial rainfall exclusion experiments to investigate the plasticity of hydraulic traits and HSM for three Mediterranean tree species (Quercus ilex L., Quercus pubescens Willd., and Pinus halepensis Mill.). For all species, a homeostasis of HSM in response to rainfall reduction was found, achieved through different mechanisms. For Q. ilex, the convergence in HSM is attributed to the adjustment of both the turgor loss point (Ψtlp) and the water potential at which 50% of xylem conductivity is lost due to embolism (P50). In contrast, the maintenance of HSM for P. halepensis and Q. pubescens is related to its isohydric behavior for the first and leaf area adjustment for the latter. It remains to be seen whether this HSM homeostasis can be generalized and if it will be sufficient to withstand extreme droughts expected in the Mediterranean region. [ABSTRACT FROM AUTHOR]

In southwestern US forests, the combined impact of climate change and increased fuel loads due to more than a century of human‐caused fire exclusion is leading to larger and more severe wildfires. Restoring frequent fire to dry conifer forests can mitigate high‐severity fire risk, but the effects of these treatments on the vegetation composition and structure under projected climate change remain uncertain.We used a forest landscape model to assess the impact of thinning and prescribed burns in dry conifer forests across an elevation gradient, encompassing low‐elevation pinyon‐juniper woodlands, mid‐elevation ponderosa pine and high‐elevation mixed‐conifer forests.Our results demonstrated that the treatments decreased the probability of high‐severity fires by 42% in the study area. At low elevation, the treatments did not prevent loss in forest cover and biomass with decreases in Pinus edulis and Juniperus monosperma abundances. At mid‐elevation, changes in fire effects maintained a greater diversity of tree species by favouring the maintenance of cohorts of old trees, in particular Pinus ponderosa which accumulated 5.41 Mg ha−1 more above‐ground biomass than without treatments by late‐century. Treatments in dry conifer forests modified fire effects beyond the treated area, resulting in increased cover and biomass of old Picea englemannii and Abies lasiocarpa cohorts.Synthesis and applications: Our findings indicate that thinning and prescribed burning can enhance tree species diversity in dry conifer forests by protecting old cohorts from stand‐replacing fires. Moreover, our results suggest that treatments mainly implemented in dry pine forests with high risk of high‐severity fires can be beneficial for subalpine species conservation by reducing the chance that high‐severity fire at mid‐elevation is transmitted into high‐elevation forest. [ABSTRACT FROM AUTHOR]

In many parts of the world, achieving a target of 30% of land managed for conservation under the Kunming‐Montreal Global Biodiversity Framework will require the protection of land with a long history of management for production. In newly protected forests, past logging practices will have impacted key aspects of stand structure, including hollow‐bearing trees that provide critical habitat for vertebrate fauna. The impacts of past silvicultural practices on hollow density, distribution, type and longevity may necessitate targeted ameliorative actions. We investigated tree hollows in the largest river red gum (Eucalyptus camaldulensis Denh.) forest in the world, which had undergone logging‐induced woody thickening prior to being converted to a conservation reserve in 2010. We recorded stem diameters and hollows in living and dead trees in 66 two‐hectare plots. Our sites sampled two productivity states and a wide range of total tree densities. On all sites, we found that hollow‐bearing tree densities were lower than reference values for unlogged stands and average density had halved relative to reference values. We found no relationship between the density of hollow‐bearing trees and total tree density, but we did find a weak positive relationship with site productivity. Larger trees had more hollows, bigger hollows and a greater diversity of hollow sizes. However, of the 1254 hollow‐bearing trees recorded, 43% were dead, 48% of the dead trees had been ringbarked. The proportion of hollow‐bearing trees that were dead was positively correlated with tree size, with 60% of trees in the largest quartile (>105 cm) recorded as dead. The prevalence of dead hollow‐bearing trees suggests that the density and diversity of hollows will continue to decline and ameliorative actions should be considered. These results highlight the need to consider the legacy of past silvicultural practices in the management of newly created conservation reserves. [ABSTRACT FROM AUTHOR]

Palo Laziale Wood is a relatively small biotope (129 ha) situated along the coast of the Metropolitan Area of Rome, Lazio region, Italy. Despite being one of the region's remaining patches of an ancient oak floodplain broad-leaved forest, it conserves numerous priority habitats and species of high conservation interest. The vegetation consists mainly of Turkey oak stands with small temporary ponds and flooded meadows. The forest underwent a dieback in 2003, triggered by a significantly hot and dry summer. In 2018, an ecological restoration project (LIFE PRIMED LIFE17 NAT/GR/000511) was initiated to restore Palo Laziale's ecosystems. This paper presents the methodological approach employed to assess the vegetation ecology of a degraded forest ecosystem. Such an investigation was a key component of the Adaptative Restoration Plan of the Project. It provided the baseline necessary for designing and calibrating the planned direct conservation actions on the target habitat types (91M0: Pannonian-Balkanic turkey oak-sessile oak forests, 3170*: Mediterranean temporary ponds, 5230*: Arborescent matorral with Laurus nobilis, etc.) and establishing reference values to enable long-term monitoring. Plant taxa comparison from 1 ha square-grid sampling and multivariate analyses were carried out to group species and identify environmental and Ellenberg-based drivers. Six ecologically distinct units were found, eventually confirming the distinctive ecological heterogeneity of Mediterranean ecosystems. Amongst these, the hygrophilous vegetation has resulted to be the one mainly affected by the dieback outbreak. Due to the high heterogeneity, introduced by the massive tree mortality, the method of regular 1 ha squares turned out to be a reliable alternative to random vegetation sampling plots (e.g., phytosociological relevés) to disentangle ecological patterns of fragmented and disturbed habitats. [ABSTRACT FROM AUTHOR]

Coastal forests on sandy beaches in Japan are mainly established by Pinus thunbergii Parl.. These forests prevent and mitigate disasters such as wind, sand, tide, and tsunami. But Pinus thunbergii die-off is progressing nationwide in Japan and the function of coastal forests is declining. Therefore, a multi-tiered forest has been proposed composed of Pinus thunbergii and broadleaf trees instead of Pinus thunbergii trees. However, few studies have quantitatively evaluated the shade-tolerance characteristics of the broadleaf trees that comprise these forests. To this end, we measured chlorophyll levels (SPAD value) in eight representative evergreen broadleaf tree species inhabiting coastal areas in Japan and evaluated their shade-tolerance. [ABSTRACT FROM AUTHOR]

In the context of the Lubumbashi Charcoal Production Basin (LCPB), the socio-economic repercussions of the COVID-19 pandemic have exacerbated pressures on populations dependent on forest resources for their subsistence. This study employs a comprehensive methodological approach, integrating advanced remote sensing techniques, including image classification, mapping, and detailed landscape analysis, to quantify alterations in forest cover within the LCPB during the pandemic period. Our findings reveal a consistent trend of declining forested area, characterized by processes of attrition and dissection observed throughout various study phases, spanning from May 2019 to November 2023. This reduction in forest cover, notably more pronounced in the vicinity of Lubumbashi city and the northern zone of the LCPB, proved to be less pronounced between November 2019 and September 2020, underscoring the influence of COVID-19 pandemic-induced confinement measures on forest management practices in the region. However, subsequent to this period of restriction, deforestation activity intensified, leading to significant landscape transformations within the LCPB, primarily attributable to expanded human activities, consequently resulting in a notable decrease in the proportion of land occupied by these natural ecosystems. Consequently, the size of the largest forest patch declined substantially, decreasing from 14.62% to 8.20% between May 2019 and November 2023, thereby fostering a heightened density of forest edges over time. Our findings provide a significant contribution to understanding the complex interactions between the COVID-19 pandemic and deforestation phenomena, emphasizing the urgent need to adopt adaptive management strategies and appropriate conservation measures in response to current economic challenges. [ABSTRACT FROM AUTHOR]

Longleaf pine (Pinus palustris Mill.) is a conifer historically associated with an open forest ecosystem that extended across much of the coastal plain of the Southeastern United States. It now exists mainly in isolated fragments following the conversion of forests and the long-term disruption of the low-intensity fire regime upon which the species depends. Recent decades have seen efforts to restore longleaf pine forests by government and private landowners. This was reflected in analyses of national forest inventory data during two time periods, ca. 2009–2015 and 2016–2021, that showed increases in the estimated number of longleaf pine trees, the area of the longleaf pine forest type, and the number and area of planted longleaf pine, along with growth in mean plot-level longleaf pine carbon and importance value. At the same time, we found a decrease in the overall forest area containing longleaf pine, manifested across a variety of other forest types. These results point to a dynamic through which forests dominated by longleaf pine are becoming more widespread via restoration, while forests in which the species is a less important component are transitioning to other forest types or land uses. We also detected a decrease over time in the estimated number of longleaf seedlings across most states and forest types and a decline in naturally regenerated longleaf pine. To further assess regeneration trends in longleaf pine, we calculated the estimated proportion of small trees (seedlings and saplings) for the entire species and for seed zone sub-populations. We found a species-wide decrease in the proportion of small trees, from 82.1 percent to 75.1 percent. This reduction was most pronounced along the edges of the species distribution and could indicate less sustainable levels of regeneration in some areas. These results underscore the challenges of facilitating natural regeneration in this important species. [ABSTRACT FROM AUTHOR]

Understanding vegetation seasonality and its driving mechanisms improves decision-making in the management of ecological systems in a warming global climate. Using multiple statistical methods (i.e., trend analysis, abrupt changes, and partial correlation analysis), this study analyzed the spatiotemporal variations in the Normalized Difference Vegetation Index (NDVI) in the Equatorial Africa (EQA) region and their responses to climate factors from 1982 to 2021. The NDVI values declined at a rate of 0.00023 year−1, while the precipitation (P) and mean temperature (TMEAN) values increased at rates of 0.22 mm year−1 and 0.22 °C year−1, respectively. The mean minimum temperature (TMIN) had a higher rate of 0.2 °C year−1 than the mean maximum temperature (TMAX) at 0.02 °C year−1. An abrupt change analysis showed that the TMAX, P, and NDVI breakpoints occurred in 2000, 2002, and 2009, respectively; TMEAN and TMIN breakpoints occurred in 2001. The NDVI trends declined in forest and cropland areas but increased in shrubland and grassland areas. The summer NDVI trends declined for all vegetation types and were reversed in the winter season. The NDVI positively correlated with the P (r = 0.50) and TMEAN (r = 0.60). All seasonal analyses varied across four seasons. A temporal analysis was conducted using partial correlation analysis (PCR), and the results revealed that TMIN had a greater impact on the NDVI (PCR = −0.45), followed by the TMAX (PCR = 0.31) and then the P (PCR = −0.19). The annual trend showed that areas with significant greening were consistent with stronger wetter and weaker warming trends. Both precipitation and temperature showed a positive relationship with vegetation in semi-arid and arid regions but a negative relationship with humid regions. Our findings improve our insight into scientific knowledge on ecological conservation. [ABSTRACT FROM AUTHOR]

Forests play a key role in the mitigation of global warming and provide many other vital ecosystem goods and services. However, as forest continues to vanish at an alarming rate from the surface of the planet, the world desperately needs knowledge on what contributes to forest preservation and restoration. Migration, a hallmark of globalization, is widely recognized as a main driver of forest recovery and poverty alleviation. Here, we show that remittance from migrants reinforces forest recovery that would otherwise be unlikely with mere migration, realizing the additionality of payments for ecosystem services for China's largest reforestation policy, the Conversion of Cropland to Forest Program (CCFP). Guided by the framework that integrates telecoupling and coupled natural and human systems, we investigate forest-livelihood dynamics under the CCFP through the lens of rural out-migration and remittance using both satellite remote sensing imagery and household survey data in two representative sites of rural China. Results show that payments from the CCFP significantly increases the probability of sending remittance by out-migrants to their origin households. We observe substantial forest regeneration and greening surrounding households receiving remittance but forest decline and browning in proximity to households with migrants but not receiving remittance, as measured by forest coverage and the Enhanced Vegetation Index derived from space-borne remotely sensed data. The primary mechanism is that remittance reduces the reliance of households on natural capital from forests, particularly fuelwood, allowing forests near the households to recover. The shares of the estimated ecological and economic additionality induced by remittance are 2.0% (1.4%∼3.8%) and 9.7% (5.0%∼15.2%), respectively, to the baseline of the reforested areas enrolled in CCFP and the payments received by the participating households. Remittance-facilitated forest regeneration amounts to 12.7% (6.0%∼18.0%) of the total new forest gained during the 2003–2013 in China. Our results demonstrate that remittance constitutes a telecoupling mechanism between rural areas and cities over long distances, influencing the local social-ecological gains that the forest policy intended to stimulate. Thus, supporting remittance-sending migrants in cities can be an effective global warming mitigation strategy. [ABSTRACT FROM AUTHOR]

Introduction: The black coral Leiopathes glaberrima is a key component of deep-sea animal forests of the Western Mediterranean and North-Atlantic hard bottoms. Due to its ecological role, biological characteristics and sensitivity to fishing activities, it has been included in the Annex II of the Barcelona Convention, listed as an endangered species in IUCN Red Lists, and recognized as an indicator of Vulnerable Marine Ecosystems by the FAO. Methods: During a survey conducted in the Strait of Sicily, 140 ROV transects were carried out allowing the characterization of environmental preferences, associated fauna and population structure of L. glaberrima in the study area. Results and discussion: 1020 colonies were distributed between 165 and 672 meters and arranged in 17 patches and isolated colonies. The average height was determined to be 40.9 ± 1.0 cm, with the range spanning from a minimum of 5 cm up to nearby 200 cm. Pristine colonies accounted for 62.9%, mainly constituted by small-sized individuals densely aggregated (up to 14.5/m2 in a single frame) in the eastern part of the area. 24.5% of the specimens were dead and localized in the western margin where we reported a rare case of mass mortality in the deep-sea environment and the first ever described for black corals, opening new scenarios regarding the possibility that these events can occur in environments previously considered safe from danger. The triggering causes of these events in inaccessible environments are actually only hypothesized, but it is not to be excluded that, sooner or later, a similar effect could potentially result from anthropogenic climate changes. [ABSTRACT FROM AUTHOR]

Water deficit is the major stress factor magnified by climate change that causes the most reductions in plant productivity. Knowledge of photosystem II (PSII) response mechanisms underlying crop vulnerability to drought is critical to better understanding the consequences of climate change on crop plants. Salicylic acid (SA) application under drought stress may stimulate PSII function, although the exact mechanism remains essentially unclear. To reveal the PSII response mechanism of celery plants sprayed with water (WA) or SA, we employed chlorophyll fluorescence imaging analysis at 48 h, 96 h, and 192 h after watering. The results showed that up to 96 h after watering, the stroma lamellae of SA-sprayed leaves appeared dilated, and the efficiency of PSII declined, compared to WA-sprayed plants, which displayed a better PSII function. However, 192 h after watering, the stroma lamellae of SA-sprayed leaves was restored, while SA boosted chlorophyll synthesis, and by ameliorating the osmotic potential of celery plants, it resulted in higher relative leaf water content compared to WA-sprayed plants. SA, by acting as an antioxidant under drought stress, suppressed phototoxicity, thereby offering PSII photoprotection, together with enhanced effective quantum yield of PSII photochemistry (ΦPSII) and decreased quantity of singlet oxygen (1O2) generation compared to WA-sprayed plants. The PSII photoprotection mechanism induced by SA under drought stress was triggered by non-photochemical quenching (NPQ), which is a strategy to protect the chloroplast from photo-oxidative damage by dissipating the excess light energy as heat. This photoprotective mechanism, triggered by NPQ under drought stress, was adequate in keeping, especially in high-light conditions, an equal fraction of open PSII reaction centers (qp) as of non-stress conditions. Thus, under water deficit stress, SA activates a regulatory network of stress and light energy partitioning signaling that can mitigate, to an extent, the water deficit stress on PSII functioning. [ABSTRACT FROM AUTHOR]

Background: Dehydration of plant tissues caused by water stress affects the dynamics of the lateral cambium, the rate of cell division and differentiation in cell lumen size, wall thickness and wall chemical properties. Based on evidence that ongoing climate change projects longer and more intense water stress conditions, forest dynamics and decline are predicted to be affected by increases in drought intensity and frequency. To verify the interaction of these phenomena, we described the modifications in the anatomy and mineral contents of annual growth rings of Araucaria araucana seedlings subjected to water stress treatments, using X-ray densitometry and X-ray fluorescence techniques. Results: Severe water stress conditions during the growing period produced narrower tree rings, with reduced cell lumen size (5–7 µm) and higher tracheid reinforcement factor values, but with lower wood density. Plants subjected to moderate water stress generated intra-annual density fluctuations coinciding with periods of decreased soil moisture. Under the precept that the essential nutrients play a relevant role in the functioning of trees, we found evidence of element allocation and concentration in response to drought. Calcium and phosphorus concentration increased significantly as stress becomes more severe, but with small differences between early- and latewood. On the contrary, potassium and sulfur presented lower values in the most stressed plants, and manganese had the lowest values only for moderate water stress. Finally, S/Ca and K/Ca molar ratios decreased, while Ca/Mn increased as stress becomes more severe. Conclusions: Our findings suggested that A. araucana seedlings invested resources aimed at increasing structural components of the cell wall to prevent cavitation. This would maintain metabolism and cell growth even in unfavorable environmental conditions. Furthermore, the imbalance of manganese and calcium and their consequent ratio (Ca/Mn) could be linked to early adaptive signals to avoid dieback. [ABSTRACT FROM AUTHOR]

Recently, as global climate change and local disturbances such as wildfires continue, long- and short-term changes in the high-latitude vegetation systems have been observed in various studies. Although remote sensing technology using optical satellites has been widely used in understanding vegetation dynamics in high-latitude areas, there has been limited understanding of various landscape changes at different spatiotemporal scales, their mutual relationships, and overall long-term landscape changes. The objective of this study is to devise a change monitoring strategy that can effectively observe landscape changes at different spatiotemporal scales in the boreal ecosystems from temporally sparse time series remote sensing data. We presented a new post-classification-based change analysis scheme and applied it to time series Landsat data for the central Yakutian study area. Spectral variability between time series data has been a major problem in the analysis of changes that make it difficult to distinguish long- and short-term land cover changes from seasonal growth activities. To address this issue effectively, two ideas in the time series classification, such as the stepwise classification and the lateral stacking strategies were implemented in the classification process. The proposed classification results showed consistently higher overall accuracies of more than 90% obtained in all classes throughout the study period. The temporal classification results revealed the distinct spatial and temporal patterns of the land cover changes in central Yakutia. The spatiotemporal distribution of the short-term class illustrated that the ecosystem disturbance caused by fire could be affected by local thermal and hydrological conditions of the active layer as well as climatic conditions. On the other hand, the long-term class changes revealed land cover trajectories that could not be explained by monotonic increase or decrease. To characterize the long-term land cover change patterns, we applied a piecewise linear model with two line segments to areal class changes. During the former half of the study period, which corresponds to the 2000s, the areal expansion of lakes on the eastern Lena River terrace was the dominant feature of the land cover change. On the other hand, the land cover changes in the latter half of the study period, which corresponds to the 2010s, exhibited that lake area decreased, particularly in the thermokarst lowlands close to the Lena and Aldan rivers. In this area, significant forest decline can also be identified during the 2010s. [ABSTRACT FROM AUTHOR]

Nest site availability plays an important role in the ecology of the birds inhabiting intensive agricultural landscapes. The removal of trees and snags due to logging is one of the main threats and the cause of the observed decline in many birds living in an agricultural landscape. When nests are lost, nesting passerines typically rebuild them for a new clutch. Additionally, relocating nests after a brood loss is a prevalent strategy used to avoid predators and brood parasites. Such a strategy is common to the Red-backed Shrike, which builds successive nests for each brood. Interestingly, clutch replacement may occur in unusual forms. This study describe three cases of Song Thrush nests reused by Red-backed Shrikes during one breeding season. The time and energy-saving behaviour or possible deterrence of nest parasitism could explain why the nests have been reused. However, due to the limited observations as compared to the total number of nests, further research is necessary to clarify this phenomenon. [ABSTRACT FROM AUTHOR]

Climate change has increased the susceptibility of forest ecosystems, resulting in escalated forest decline globally. As one of the largest forest biomasses in the Northern Hemisphere, the Eurasian boreal forests are subjected to frequent drought, windthrow, and high-temperature disturbances. Over the last century, bark beetle outbreaks have emerged as a major biotic threat to these forests, resulting in extensive tree mortality. Despite implementing various management strategies to mitigate the bark beetle populations and reduce tree mortality, none have been effective. Moreover, altered disturbance regimes due to changing climate have facilitated the success of bark beetle attacks with shorter and multivoltine life cycles, consequently inciting more frequent bark beetle-caused tree mortality. This review explores bark beetle population dynamics in the context of climate change, forest stand dynamics, and various forest management strategies. Additionally, it examines recent advancements like remote sensing and canine detection of infested trees and focuses on cutting-edge molecular approaches including RNAi-nanoparticle complexes, RNAi-symbiotic microbes, sterile insect technique, and CRISPR/Cas9-based methods. These diverse novel strategies have the potential to effectively address the challenges associated with managing bark beetles and improving forest health in response to the changing climate. [ABSTRACT FROM AUTHOR]

Despite three decades of policies discouraging biomass-based cooking in Africa, demand for fuelwood continues to rise. Several studies focus on household energy use, but few consider the role of commercial premises such as bakeries in deforestation, despite growing demand for bread. This study examines bread production by commercial bakeries in forest communities in Nigeria, investigating (a) the energy sources used, (b) the changes to forests and (c) the factors that could enable bakeries to transition towards clean energy. Mixed methods were used including questionnaire surveys, land use change mapping and assessments of forest plots. Questionnaires with 21 bakeries in two northern Nigerian states (Kaduna, Nasarawa) and Abuja Federal Capital Territory suggest that they depend heavily on fuelwood, collected directly from the forest, or purchased from (largely female) suppliers, retailers or wholesalers. Bakeries most commonly use Anogeissus leiocarpa mainly due to its burning quality and availability. Remote sensing data show declines in forest cover from 71% (56,157 km2) in 2000 to 49% (38,756 km2) in 2020. While all bakeries were willing to transition to more sustainable energy sources, training on alternative fuels and more energy efficient ovens is required. Policies supporting energy transition must consider all value chain actors, not just fuelwood consumers, recognising that women play a key role in fuelwood sales at the community level. Transition efforts need to be underpinned by detailed analyses of trade-offs so that measures to reduce undesirable livelihood impacts can be established, and should consider more efficient ovens as well as stoves. [ABSTRACT FROM AUTHOR]

This paper reports a study of bioclimatic dynamics and land use in the region of Tlemcen (north-west of Algeria). GIS (geographic information system) and satellite images (LandSat) were used to conduct a diachronic study based on a series of satellite images from the years 2000 and 2019 to demonstrate changes in the study area while highlighting the importance of environmental conditions, including climate and anthropogenic impact on dynamic vegetation cover. Bioclimatic synthesis has shown an improvement in the rainfall regime and an evolution towards higher bioclimatic atmospheres between the two periods (1985–1999) and (2004–2018). Land use in the study area is under the influence of strong anthropogenic pressures and is experiencing a decline in forest areas from 28.74 to 17.49% but also in agricultural land and lawns from 38.61% to 27.67% in favour of built-up areas which increased from 0.81% to 1.09% but mainly to the benefit of bare soil: an ultimate stage of degradation whose surface area increased from 31.59% in 2000 to 53.46% in 2019. [ABSTRACT FROM AUTHOR]

In recent years, long periods of drought and heat waves have become increasingly frequent, causing forest dieback phenomena that make stands more sensitive to biotic stressors. How trees may respond to extreme climatic events and which metabolites are involved under stress conditions is still not clear. In this study, using Solid Phase Micro-Extraction (SPME)-GC/MS, we analysed how dieback (D) and non-dieback (ND) Hungarian oak trees from the San Paolo Albanese site respond to these climatic dynamics, focusing on volatile organic compounds (VOCs). For each group of trees, three wood samples were taken, and each was divided into four sub-samples with five growth rings and subjected to SPME and increase in basal area (BAI) analysis of the last 20 years. Dieback trees had a lower number of leaves, and this condition may translate into less photosynthesis, less organic matter production, and lower reserves of carbohydrates being available for growth. Indeed, D trees showed lower radial increases and a lower content of aldehydes, terpenes, and fatty acids than ND trees, indicating a better health of ND trees compared to D trees. Meanwhile, D trees showed a reduction in terpenes, such as α-pinene, γ-eudesmol, and cyperene (with significant insecticidal activity), a reduction in aromatic aldehydes, such as furfural and 5-methylfurfural, and an increase in silanols (with antimicrobial function). Considering the different compounds' contents between D and ND trees, our study could be useful for detecting bio-indicators to identify an early warning signal of dieback phenomena. [ABSTRACT FROM AUTHOR]

Worldwide studies have related recent forest decline and mortality events to warmer temperatures and droughts, as well as pointing out a greater vulnerability to climate changes in larger trees. Previous research performed on silver fir (Abies alba Mill.) suggest an increasing decline and mortality, mainly related to rising water shortages. Here, we investigate these die-off events in two silver fir populations at the rear edge of the species in the western Pyrenees. We used dendrochronology to investigate tree age, size (diameter) and individual climate sensitivity (climate–growth relationships) as predisposing factors related to growth patterns and drought resilience indexes in canopy-level declining and non-declining trees. The regional climate was also investigated, including temperature trends, quantile regression in precipitation and frequency of extreme events in drought indexes (SPEI). The regional climate was characterized by an increase in mean temperatures and a higher frequency of extreme drought events in recent decades, without a decrease in total precipitation. Larger trees were more sensitive to temperature and prone to decline. Declining trees presented decreasing growth trends years ago, providing a robust predisposing trait. Both populations were not different in mean growth, despite the contrasting local climate and management legacies, although we identified a higher resilience to drought in the eastmost stand. A significant regression was found between growth trends and climate sensitivity, supporting that declining trees are more sensitive to warmer temperatures and drought. Hence, the results support a contrasting climate sensitivity related to tree size (but not to tree age), suggesting impending decline and mortality in large trees with higher temperature sensitivity (negative temperature–growth correlations). Nonetheless, contributing factors, such as the legacy of previous logging, should also be accounted for. [ABSTRACT FROM AUTHOR]

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Air pollution caused by tropospheric ozone contributes to the decline of forest ecosystems; for instance, sacred fir, Abies religiosa (Kunth) Schltdl. & Cham. forests in the peri-urban region of Mexico City. Individual trees within these forests exhibit variation in their response to ozone exposure, including the severity of visible symptoms in needles. Using RNA-Seq metatranscriptomic data and ITS2 metabarcoding, we investigated whether symptom variation correlates with the taxonomic and functional composition of fungal mycobiomes from needles collected in this highly polluted area in the surroundings of Mexico City. Our findings indicate that ozone-related symptoms do not significantly correlate with changes in the taxonomic composition of fungal mycobiomes. However, genes coding for 30 putative proteins were differentially expressed in the mycobiome of asymptomatic needles, including eight genes previously associated with resistance to oxidative stress. These results suggest that fungal communities likely play a role in mitigating the oxidative burst caused by tropospheric ozone in sacred fir. Our study illustrates the feasibility of using RNA-Seq data, accessible from global sequence repositories, for the characterization of fungal communities associated with plant tissues, including their gene expression. [ABSTRACT FROM AUTHOR]

Summary: Rising atmospheric carbon dioxide concentrations (CO2) and atmospheric nitrogen (N) deposition have contrasting effects on ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) symbioses, potentially mediating forest responses to environmental change.In this study, we evaluated the cumulative effects of historical environmental change on N concentrations and δ15N values in AM plants, EM plants, EM fungi, and saprotrophic fungi using herbarium specimens collected in Minnesota, USA from 1871 to 2016. To better understand mycorrhizal mediation of foliar δ15N, we also analyzed a subset of previously published foliar δ15N values from across the United States to parse the effects of N deposition and CO2 rise.Over the last century in Minnesota, N concentrations declined among all groups except saprotrophic fungi. δ15N also declined among all groups of plants and fungi; however, foliar δ15N declined less in EM plants than in AM plants. In the analysis of previously published foliar δ15N values, this slope difference between EM and AM plants was better explained by nitrogen deposition than by CO2 rise.Mycorrhizal type did not explain trajectories of plant N concentrations. Instead, plants and EM fungi exhibited similar declines in N concentrations, consistent with declining forest N status despite moderate levels of N deposition. [ABSTRACT FROM AUTHOR]

Mediterranean areas will likely undergo climate shifts in the near future that modify the water resources for vegetation. However, in some regions of southwestern Spain, such as Extremadura, the impact of different future scenarios on the water resources for vegetation has not been studied extensively. This study focused on the quantification and spatial distribution of water resources for vegetation covers in Extremadura and analyzed the impact of future climate change scenarios on those water resources. For this, five downscaled global climate models from Coupled Model Intercomparison Project phase 6 (CMIP6) were used in four future periods (from 2021 to 2100) following two Shared Socioeconomic Pathways (SSP-2.45 and SSP-5.85). These projections were compared with a historical baseline period (1970–2000) to obtain the variation of water resources. The results showed decreases in the water resources for all the scenarios and periods analyzed compared to those observed in the historical baseline period. The smallest decreases were noted over 2041–2060 for SSP2-4.5, with almost 74% of the region decreasing between 15 and 18% (with an average of 16.4%). The greatest decreases were over 2081–2100 for SSP5-8.5, in which 90% of the region displayed water resource declines of greater than 50%. In this last situation, the three more widespread vegetation covers (agrosilvopastoral systems of dehesas, grasslands, and crops) underwent similar declines of around 55% of their water resources (from ≈203 to ≈93 mm), while the fourth widely spread vegetation cover, forests, declined by 49% (from ≈261 to ≈133 mm). If any of these future projections occur, the decline in water resources could modify the forest composition and structure of these water-dependent ecosystems, compromising their maintenance and ecological, cultural, and economic functions. [ABSTRACT FROM AUTHOR]

Forest decline and dieback are growing phenomena worldwide, resulting in severe, large‐scale degradation of the canopy. This can profoundly alter the provision of trophic resources and microhabitats for canopy‐dwelling arthropods.In 2019, we assessed the effect of oak decline on the community of canopy‐dwelling Hymenoptera. We selected 21 oak stands and 42 plots, located in three forests in France, presenting contrasting levels of decline. Insects were sampled at the canopy level with green multi‐funnel and flight‐interception traps.We collected a particularly diverse community of 19,289 insect individuals belonging to 918 taxa, 10 larval trophic guilds and 7 nesting guilds.Oak decline had no effect on the abundance or richness of the overall community but significantly reshaped the community assemblages. Decline had contrasting effects depending on the taxa and guilds considered. Specialist parasitoids were more abundant at intermediate levels of decline severity while generalists were negatively affected. Taxa depending on ground‐related resources and microhabitats were promoted. Saproxylic taxa were more abundant while xylophagous insects were negatively impacted.Reduced leaf area index promoted several guilds and the diversity of the overall community. While an increasing tree mortality rate enhanced the abundance and diversity of deadwood resources, it had negative impacts on several Hymenoptera guilds. Our results suggest that micro‐environmental changes at the ground level due to canopy decline have major cascading effects on the communities of canopy‐dwelling Hymenoptera.Our study highlights the relevance of studying Hymenoptera communities to investigate the outcomes of disturbances on forest biodiversity. [ABSTRACT FROM AUTHOR]

Summary: A specific, robust threshold for drought‐induced tree mortality is needed to improve the prediction of forest dieback. Here, we tested the relevance of continuous measurements of stem diameter variations for identifying such a threshold, their relationship with hydraulic and cellular damage mechanisms, and the influence of growth conditions on these relationships.Poplar saplings were grown under well‐watered, water‐limited, or light‐limited conditions and then submitted to a drought followed by rewatering. Stem diameter was continuously measured to investigate two parameters: the percentage loss of diameter (PLD) and the percentage of diameter recovery (DR) following rewatering. Water potentials, stomatal conductance, embolism, and electrolyte leakage were also measured, and light microscopy allowed investigating cell collapse induced by drought.The water release observed through loss of diameter occurred throughout the drought, regardless of growth conditions. Poplars did not recover from drought when PLD reached a threshold and this differed according to growth conditions but remained linked to cell resistance to damage and collapse.Our findings shed new light on the mechanisms of drought‐induced tree mortality and indicate that PLD could be a relevant indicator of drought‐induced tree mortality, regardless of the growth conditions. [ABSTRACT FROM AUTHOR]

Ecological records from before and after the creation of natural parks are valuable for informing conservation and management but are often unavailable. High-resolution paleoecological studies may bridge the gap and provide the required information. This paper presents a 20th-century subdecadal reconstruction of vegetation and landscape dynamics in a national park of the Pyrenean highlands. The park lands had traditionally been used for cultivation, extensive grazing, forest exploitation, and hydroelectricity generation following the damming of numerous glacial lakes. A significant finding is that forests have dominated the landscape, with negligible changes in composition, and only experienced fluctuations in forest cover, influenced by both climatic and anthropogenic factors. The creation of the park (1955) and the initial restrictions on forest exploitation did not significantly affect vegetation cover or composition. Major forest expansion did not occur until several decades later, 1980, when the park was enlarged and forest exploitation was further restricted. This expansion peaked in the 1990s, coinciding with a warming trend and a decrease in fire incidence, before declining due to warmer and drier climates. This decline was coeval with the ongoing global forest dieback and may be exacerbated by the predicted global warming in this century, which could also increase fire incidence due to dead-wood accumulation. Currently, the main threats are global warming/drying, fire, and tourism intensification. Similar high-resolution paleoecological records in protected areas are globally scarce and would be capable in providing the long-term ecological scope required to properly understand forest dynamics and optimize conservation measures. [ABSTRACT FROM AUTHOR]

An increased frequency and severity of droughts and heat waves have resulted in increased tree mortality and forest dieback across the world, but underlying mechanisms are poorly understood. We used a common garden experiment with 20 conifer tree species to quantify mortality after three consecutive hot, dry summers and tested whether mortality could be explained by putative underlying mechanisms, such as stem hydraulics and legacies affected by leaf life span and stem growth responses to previous droughts. Mortality varied from 0 to 79% across species and was not affected by hydraulic traits. Mortality increased with species' leaf life span probably because leaf damage caused crown dieback and contributed to carbon depletion and bark beetle damage. Mortality also increased with lower growth resilience, which may exacerbate the contribution of carbon depletion and bark beetle sensitivity to tree mortality. Our study highlights how ecological legacies at different time scales can explain tree mortality in response to hot, dry periods and climate change. [ABSTRACT FROM AUTHOR]

The south‐eastern corner of the Australian continent was once crisscrossed by the nomadic flight paths of the Regent Honeyeater. For hundreds of thousands of years, they winged their way up and down this vast continent. Today, however, the species is listed as critically endangered and is just clinging to existence. This multimedia essay tells the story of this decline, exploring the complex, co‐shaping, relationships between individual birds and their flocks, their songs, and their forests. While these are relationships that might be glossed as being social, cultural, and ecological (respectively), and so belonging to separate domains of life, they are in reality delicately interwoven elements of what it is to be a Regent Honeyeater; relationships that, taken together, have been integral to the emergence and ongoing life of this species. In attending to the breakdown of these relationships in our present time, this essay seeks to develop new resources for storying loss in a time of ongoing extinctions. Bringing text into conversation with images and audio, the essay works to draw the reader/viewer/listener into an encounter with an unravelling world. Ultimately, our aim has been to create an essay in which the conceptual ideas, the design, and the biology of the species described, are brought into some sort of alignment that allows them to become mutually reinforcing elements of a storied encounter. Our reflection on the process of creating this essay are provided in the accompanying exegetical commentary. [ABSTRACT FROM AUTHOR]

Burundi is on the verge of a climate and environmental catastrophe due to an interlinked combination of extreme poverty, explosive population growth, over-reliance on biomass energy sources and rapidly declining forest cover in the largely agrarian country. 100 per cent of its internally displaced population are climate change-related displacements, yet the government struggles with balancing strict climate regulations alongside promoting voluntary climate change behavioural changes. This paper critically analyses the reformation of Burundi's climate change legal framework utilising a 'Carrot and Stick' legal approach to engender a transition to cleaner energy sources and promote climate mitigation and adaptation. The paper examines the key drivers of a sustainable climate change legal framework, the mechanisms of adopting a 'carrot-and-stick' approach to climate change regulation and the delicate structuring of Burundi's regulatory framework to effectively punish and persuade households to adopt climate change goals in their energy and agricultural activities. [ABSTRACT FROM AUTHOR]

Globally, animals that are range-restricted are frequently becoming species of conservation concern, in part due to competitive exclusion by phylogenetically and ecologically similar species that are more tolerant of human disturbance. However, climate and land use changes to natural landscapes can create pockets of refugia for range-restricted species. Western gray squirrels (Sciurus griseus) are native to the west coast of North America, principally California and western Oregon. Over the past several decades, Western Gray Squirrel populations have declined in human-dominated areas, with increased competition from introduced congeneric species native to eastern North America cited as a primary driver. Despite declines in their established range west of the Pacific Crest in western North America, western gray squirrels are extending their range into the Great Basin, where they were not historically found. Using a network of remote camera traps deployed across the Sierra Nevada–Great Basin ecotone in northwestern Nevada, we detected western gray squirrels across 16 of 100 camera-trapping sites. The majority of detections were located in piñon–juniper woodland, a land cover type not previously occupied by this species. Occupancy modeling revealed that western gray squirrels were equally likely to occur in piñon–juniper woodland compared to mature pine forest that they occupy elsewhere in their range. A species distribution model parameterized with historical gray squirrel observations (pre-1950), indicated increased climatic suitability for the species on the eastern side of the Sierra Nevada in recent decades, which may have facilitated this range expansion. Our findings reveal the potential for species declining in their historical range to colonize novel habitats that become increasingly suitable as a result of human-driven changes to ecosystems. [ABSTRACT FROM AUTHOR]

Quantifying biodiversity trends in economically developed countries, where depopulation, associated secondary succession, and climate warming are ongoing, provides insights for global biodiversity conservation in the 21st century. However, few studies have assessed the impacts of secondary succession and climate warming on species' population trends at a national scale. We estimated the population trends of common breeding bird species in Japan and examined the associations between the overall population trend and species traits with the nationwide bird count data on 47 species collected from 2009 to 2020. The overall population trend varied among species. Four species populations increased moderately, 18 were stable, and 11 declined moderately. Population trends for 13 species were uncertain. The difference in overall trends among the species was associated with their habitat group and temperature niche. Species with relatively low‐temperature niches experienced more pronounced declines. Multispecies indicators showed a moderate increase in forest specialists and moderate declines in forest generalists (species that use both forests and open habitats) and open‐habitat specialists. Forest generalists and open‐habitat specialists also declined more rapidly at sites with more abandoned farmland. All species groups showed an accelerated decline or decelerated increase after 2015. These results suggest that common breeding birds in Japan are facing deteriorating trends as a result of nationwide changes in land use and climate. Future land‐use planning and policies should consider the benefits of passive rewilding for forest specialists and active restoration measures (e.g., low‐intensive forestry and agriculture) for nonforest specialists to effectively conserve biodiversity in the era of human depopulation and climate warming. [ABSTRACT FROM AUTHOR]

Groundwater serves as the primary source of freshwater in arid and semi-arid regions, rendering them resilient against precipitation scarcity. Various aspects of the drought phenomenon necessitate the application of multivariate analysis and composite drought indices. These composite indices afford a more comprehensive understanding of various drought types. However, few studies have considered the integration of meteorological and groundwater drought information. This research delves into determining a threshold for triggering the transition from meteorological drought to groundwater drought in an arid region (Minab plain). It introduces the Joint Deficit Meteo-Groundwater Drought Index, a result of combining two droughts based on copula function. Furthermore, trivariate drought frequency analysis (severity-duration-peak) is conducted based on three scenarios in three clusters of the Minab Plain. Drought risk is then assessed using conditional probability. The results indicate that the northern and central parts of the Minab Plain face a high risk of meteo-groundwater drought. With increasing drought duration and severity, the peak also rises, placing the entire region at risk of widespread drought. A comprehensive understanding of meteo-groundwater drought and an assessment of its characteristics provide insights into the signals of propagation from meteorological drought to groundwater, facilitating the management of groundwater and surface water resources to mitigate the effects of drought. [ABSTRACT FROM AUTHOR]

Tropical forest productivity represents an important global carbon sink, but many tropical forests grow on infertile soils. Efficient nutrient cycling by litterfall has long been assumed to maintain tropical tree growth, but there is no direct evidence that the nutrients cycled in litterfall are essential for tropical forest productivity.To test whether nutrient cycling by litterfall maintains tropical forest above‐ground productivity, we established large‐scale long‐term litter removal (L−) and litter addition (L+) treatments in a mature lowland tropical forest. We hypothesised that the removal of nutrients in litter would reduce tree growth, survival and litter production in L− plots. By contrast, the addition of nutrients in litter would enhance tree growth, survival and litter production in L+ plots. To test our hypotheses, we recorded tree growth and survival every 2 years, and measured litterfall monthly during 17 years of treatments.Tree growth and litterfall declined over time in L− plots, with consistently lower growth rates compared to controls after 8 years, and lower litter production after 4 years of treatments. By contrast, although litterfall was higher in the L+ plots relative to the controls, there was only a minor transient increase in tree growth immediately after the start of treatments. Tree survival declined over time in all treatments but was not affected by litter manipulation.The long‐term decline in tree growth and litterfall in the L− plots provides the first empirical evidence that nutrient cycling by litterfall plays a key role in maintaining above‐ground productivity in this tropical forest. By contrast, the transient increase in growth in the L+ plots can be attributed to the large inputs of nutrients with the addition of the entire litter standing crop at the start of treatments. The addition of nutrients in litter over the long term was nonetheless sufficient to enhance litter production, possibly by accelerating leaf turnover.Synthesis: Efficient nutrient cycling by litterfall makes an important contribution to the annual nutrient requirements of mature tropical forest trees, compensating for infertile soils. Disturbances that disrupt this finely balanced cycle could therefore reduce biomass carbon sequestration in tropical forests. [ABSTRACT FROM AUTHOR]

There is persistent uncertainty about how integrated plant functions, like growth, are mechanistically constrained and practically predicted by functional traits. For trees, these knowledge gaps persist for two reasons: First, studies of 'natural' forests are observational, with highly variable and confounding resource limitation and competition; second, most studies investigate only a few popular traits and ignore context‐dependencies in trait effects on growth (e.g. trait–environment or trait–ontogeny interactions).We assessed 17 traits as predictors of radial growth and aboveground carbon sequestration for 182 trees, including individuals of 42 species common to temperate cities. By focusing exclusively on planted trees growing in isolation, our unique study is a pseudo‐experiment that spans a large range of taxonomic and trait variability, and minimizes confounding effects of environmental heterogeneity (e.g. shifts in light availability with tree size). Focal traits included not only commonly measured traits related to leaf economics and plant size, but also wood traits and whole‐plant phenology.Models with indices of tree ontogeny (size) and traits explained 80% and 72% of variability in relative growth and carbon sequestration, respectively, and traits accounted for ~20% of the variation. Traits related to said tree functions included leaf dry matter content (LDMC), leaf N content, mature height, wood anatomy and phenology. LDMC was positively correlated with wood growth and C sequestration across all size classes, while the positive effects of leaf N, mature height and wood density were only apparent for smaller trees. Ring‐porous species had higher rates of growth and C sequestration than diffuse‐porous species.Consistent with recent theory, growth rates of isolated, urban trees vary as function of simple and interactive effects of traits and size. Our findings are useful for optimizing reforestation efforts in temperate cities, where planners and land managers can select species for rapid growth and C sequestration using freely available data for the 'effect' traits we identified, including wood anatomy and density, leaf N, and LDMC. Lastly, the trait–growth relationships we describe here may reflect those of 'naturally' isolated trees growing in savannas and/or woodlands and provide an insightful frame of reference for trees in closed‐canopy forests. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

In recent years, restoration on former grassland sites has been widely encouraged globally, aiming to address the historical loss of 90% of ancient species‐rich grasslands, and to mitigate the associated threat to grassland biodiversity. The objective of our study was to investigate on a small‐scale how plant species spontaneously colonize restored grasslands. We inventoried 275 permanent plots twice (in 2019 and 2021) in a restored grassland, following the removal of a conifer plantation. Species richness and vegetation cover in surveyed plots were dependent on grazing activity and distance to adjacent grassland. Plant species associated with forest habitats declined, while the occurrence of generalist species together with a few grassland specialists generally increased. However, not all grassland specialists gained occurrence and the colonization pattern was not consistent over time, possibly due to the lack of continuous seed arrival and low livestock activity and hence lack of disturbance. These results suggest that successful colonization of plant species benefits from links to species‐rich sites adjacent to the restoration target, with spatial dispersal and improved conditions for species establishment being key to species occurrence. Both dispersal and establishment potential are likely facilitated through the presence of grazing livestock with access to both species‐rich grasslands and restoration targets. However, the shift towards a more typical grassland community takes place gradually, with vulnerable populations of early colonizing grassland species prone to local extinction in short‐term. As a result, continued functional connectivity provided by grazing animals is necessary to improve the diversity of the restored site and ensure the establishment of grassland specialists and to maintain the plant community composition. [ABSTRACT FROM AUTHOR]

Mountain forests provide multiple benefits but are threatened by climate change-induced forest dieback. Although many studies summarize perceptions of forest ecosystem services, relatively few deal with mountain forests. The local population's perception of forest dieback in mountain forests in relation to climate change has rarely been investigated so far. Their perspective is relevant as local people are often deeply attached to "their" forests, they actively use forest ecosystems and—as voters and taxpayers—they need to support the state's adaptation and funding measures. Therefore, this study investigates the climate change and forest dieback perception of local inhabitants in two mountain areas of Southern Germany (the German Alps and the Bavarian Forest) with a quantitative survey based on representative online samples (n = 709). Relying conceptually on van der Linden's (J Environ Psychol 41:112–124, 2015. https://doi.org/10.1016/j.jenvp.2014.11.012) climate change risk perception model, the results show that experiential processing, cognitive and socio-cultural factors are related to locals' forest dieback and climate change perception, while socio-demographics show no or few connections. Nearly two-thirds (64.7%) of the respondents perceive moderate to strong forest dieback, while more than half (55.0%) of the respondents already observe consequences of climate change. The perceptions of climate change and forest dieback are positively correlated with medium to high strength. This shows that forest dieback could be interpreted as an indicator of climate change, which is difficult to observe due to its long-term nature. We identify three groups of respondents regarding preferred forest adaptation strategies to climate change. In general, respondents support nature-based forest adaptation strategies over intense measures. [ABSTRACT FROM AUTHOR]

The analysis of willow forest decline in the Jarama River has been assessed through the study of morphological river conditions in three periods (1956, 1998 and 2018) together with active channel mobility ratios and changes in channel planform and vegetation coverage. Species composition of current riparian corridors at river segment scale and monitored natural recruitment of pioneer species at local scale have been studied. Jarama River has changed from wide active wandering towards narrower meandering channels with dense and continuous riparian over-greening corridors, in which willow formations are threatened, and drought-tolerant species have colonised it. Landform evolution shows an intensive 'maturation' associated with 'anthropisation' processes during the first period, while stability dominates nowadays. Results show a generalised aging and progressive mortality of shrub willows and the expansion of forests dominated by Fraxinus angustifolia, likely associated to the progressive reduction of channel mobility and the lack of bare gravel bars for pioneer recruitment. The dominant willow species is Salix salviifolia, a drought tolerant willow that has been able to withstand the processes of 'maturation' and channel narrowing being widely distributed throughout the riparian section. On the other hand, other strict pioneer willows such as Salix eleagnos and Salix purpurea are very rare and are found in the few gravel banks that remain on the shore. Results predict a gradual disappearance of willows in the Jarama River as there is no significant recruitment, and they would last as long if those old specimens may survive. [ABSTRACT FROM AUTHOR]

Recent drought, wildfires and rising temperatures in the western US highlight the urgency of increasing resiliency in overstocked forests. However, limited valuation information hinders the broader participation of beneficiaries in forest management. We assessed how historical disturbances in California's Central Sierra Nevada affected live biomass, forest water use and carbon uptake and estimated marginal values of these changes. On average, low‐severity wildfire caused greater declines in forest evapotranspiration (ET), gross primary productivity (GPP) and live biomass than did commercial thinning. Low‐severity wildfires represent proxies for prescribed burns and both function as biomass removal to alleviate overstocked conditions. Increases in potential runoff over 15 years post‐disturbance were valued at $108,000/km2 for commercial thinning versus $234,000/km2 for low‐severity wildfire, based on historical water prices. Respective declines in GPP were valued at −$305,000 and −$1,317,000/km2, based on an average social cost of carbon. Considering biomass levels created by commercial thinning and low‐severity fire as more‐sustainable management baselines for overstocked forests, carbon uptake over 15 years post‐disturbance can be viewed as a benefit rather than loss. Realizing this benefit upon management re‐entry may require sequestering thinned material. High‐severity wildfire and clearcutting resulted in greater declines in ET and thus greater potential water benefits but also substantial declines in GPP and live carbon. These lessons from historical disturbances indicate what benefit ranges from fuels treatments can be expected from more‐sustainable management of mixed‐conifer forests and the importance of setting an appropriate baseline. [ABSTRACT FROM AUTHOR]

Carbon sequestration in the forests of the eastern United States is an important offset to the country's CO2 emissions. Much of the eastern forestland is the product of reforestation of abandoned agricultural land or recovery following clear‐cutting over a century ago. This has led to concerns that eastern forests are even‐aged and that rates of carbon sequestration will decline as forests increase in carbon. Our objective was to examine the successional dynamics of forest carbon sequestration—using live tree carbon stocks as a proxy for successional status—for the six broadly defined forest types present in the region. We used datasets from the National Forest Inventory (NFI) for the 31 US states from Minnesota south to Louisiana and eastward and analyzed live tree net carbon increment for 2007–2021, the period for which NFI plot remeasurement data were available for all 31 states. Spruce–fir and southern pines were the only forest types for which carbon increment declined even modestly over a significant fraction of the range of live tree carbon observed in the region, and southern pine–hardwood forests were the only forests in which predicted sequestration in live tree carbon declined to zero within the range of carbon stocks observed in the region. Northern hardwood–conifer forests, oak–hickory forests, and lowland forests experienced either no decline or a slight increase in sequestration in live tree carbon across the range of successional status observed in the region. Thus, the average stocks of live tree carbon per unit area increased steadily over the study period. At some point in succession, rates of mortality are expected to increase and balance gross growth, leading to zero net sequestration in live tree carbon. Mature and old‐growth stands, however, are rare in all six forest types, and mortality as a fraction of live tree carbon for all six forest types declined across the range of successional status present in the region. Our results thus provide no support for the hypothesis that the successional dynamics of forests in this region can be expected to lead to near‐term declines in net carbon sequestration. [ABSTRACT FROM AUTHOR]

This study explores the interplay between environmental quality and healthcare spending in five North African countries from 1990 to 2019, considering key socioeconomic variables as determinants. We observe a growing trend in healthcare expenditure, signaling a dedication to improving healthcare systems. Nevertheless, sporadic declines, particularly post-2010 in Libya and Tunisia, highlight the vulnerability of healthcare infrastructure to external shocks, underlining the synergy between healthcare, political stability, and economic development. Simultaneously, the study underscores the potential threat of CO2 emissions to healthcare costs, emphasizing the intrinsic connection between environmental quality and healthcare expenses. Income significantly propels healthcare spending, mirroring the region's pursuit of enhanced living standards and healthcare access. Notably, investments in healthcare infrastructure play a substantial role. Furthermore, the adverse impact of trade openness on healthcare spending stresses the importance of equitable resource allocation and effective healthcare policy implementation. The positive influence of population density underscores the need for tailored healthcare strategies addressing the region's diverse healthcare requirements. Additionally, the U-shaped relationship between healthcare expenditure and CO2 emissions suggests that the studied countries have low pollution levels and have not incurred significant healthcare costs from emissions. However, as they grow economically, environmental conservation becomes crucial to avert harm and resource depletion. While acknowledging limitations like data quality and the need for a more extended time series analysis, a comprehensive approach to healthcare systems, and a holistic view of environmental factors, this study significantly contributes to comprehending the dynamics of healthcare spending, environmental quality, and economic development in North Africa. [ABSTRACT FROM AUTHOR]

Drought‐induced groundwater decline and warming associated with climate change are primary threats to dryland riparian woodlands. We used the extreme 2012–2019 drought in southern California as a natural experiment to assess how differences in water‐use strategies and groundwater dependence may influence the drought susceptibility of dryland riparian tree species with overlapping distributions. We analyzed tree‐ring stable carbon and oxygen isotopes collected from two cottonwood species (Populus trichocarpa and P. fremontii) along the semi‐arid Santa Clara River. We also modeled tree source water δ18O composition to compare with observed source water δ18O within the floodplain to infer patterns of groundwater reliance. Our results suggest that both species functioned as facultative phreatophytes that used shallow soil moisture when available but ultimately relied on groundwater to maintain physiological function during drought. We also observed apparent species differences in water‐use strategies and groundwater dependence related to their regional distributions. P. fremontii was constrained to more arid river segments and ostensibly used a greater proportion of groundwater to satisfy higher evaporative demand. P. fremontii maintained ∆13C at pre‐drought levels up until the peak of the drought, when trees experienced a precipitous decline in ∆13C. This response pattern suggests that trees prioritized maintaining photosynthetic processes over hydraulic safety, until a critical point. In contrast, P. trichocarpa showed a more gradual and sustained reduction in ∆13C, indicating that drought conditions induced stomatal closure and higher water use efficiency. This strategy may confer drought avoidance for P. trichocarpa while increasing its susceptibility to anticipated climate warming. Key Points: Dryland riparian cottonwoods used shallow soil moisture when available but ultimately relied on groundwater for survival during droughtSpecies had different water‐use strategies related to their distribution along a gradient of increasing aridity with distance from coastPopulus trichocarpa appears more susceptible to warming, and P. fremontii more vulnerable to groundwater decline due to high water demand [ABSTRACT FROM AUTHOR]

Tree mortality and forest dieback episodes are increasing due to drought and heat stress. Nevertheless, a comprehensive understanding of mechanisms enabling trees to withstand and survive droughts remains lacking. Our study investigated basal area increment (BAI), and δ13C-derived intrinsic water-use-efficiency (iWUE), to elucidate beech resilience across four healthy stands in Italy with varying climates and soil water availability. Additionally, fist-order autocorrelation (AR1) analysis was performed to detect early warning signals for potential tree dieback risks during extreme drought events. Results reveal a negative link between BAI and vapour pressure deficit (VPD), especially in southern latitudes. After the 2003 drought, BAI decreased at the northern site, with an increase in δ13C and iWUE, indicating conservative water-use. Conversely, the southern sites showed increased BAI and iWUE, likely influenced by rising CO2 and improved water availability. In contrast, the central site sustained higher transpiration rates due to higher soil water holding capacity (SWHC). Despite varied responses, most sites exhibited reduced resilience to future extreme events, indicated by increased AR1. Temperature significantly affected beech iWUE and BAI in northern Italy, while VPD strongly influenced the southern latitudes. The observed increase in BAI and iWUE in southern regions might be attributed to an acclimation response. [ABSTRACT FROM AUTHOR]