Search

Basic ecological theory suggests that a tradeoff between competitiveness and stress tolerance dictates species range limits at regional extents. However, empirical support for this key theory remains deficient because the necessary spatial and temporal coverage and scalability of field observations has rarely been achieved. We harnessed an extensive dendroecological network (> 22 000 tree‐ring samples from 816 forest inventory plots) to disentangle competition‐limited from climate‐limited growth in both overstory and understory trees. Growth synchrony among trees thereby served as an integral metric of climate sensitivity, an approach that we justify in supplementary analyses of growth responses to temperature, precipitation, and the standardized precipitation‐evapotranspiration index. Sampling plots were arranged along elevational climate and vegetation gradients throughout the Carpathian Mountains, ranging from mixed‐species lowland forests to coniferous forests at high elevations. With mixed‐effect modelling, we also identified non‐climatic factors (stand characteristics, species diversity, and disturbance history) that modulate spatial patterns in the growth rate and synchrony of European beech Fagus sylvatica and Norway spruce Picea abies. Beech exhibited reduced growth and increased climate sensitivity towards higher elevations but performed better when species diversity was higher. The growth of spruce increased towards its lower range boundary, but understory cohorts grew poorly under interspecific competition. Overall, climate sensitivity was lower in more productive stands with benign climatic conditions and in recently disturbed sites with reduced stand density. These contrasting performances at mid‐elevations where the two species overlap (900–1300 m a.s.l.) reflect their evolutionary history, which enables them to be competitive (beech) or cold‐stress tolerant (spruce). This history will affect interactions between the two species under climate warming and shape macroecological patterns in the Carpathian ecoregion and likely other parts of Europe. Our findings point to a growing advantage of competitively stronger species in montane and subalpine vegetation zones. [ABSTRACT FROM AUTHOR]

Forest plantations play an increasingly important role in meeting global demand for wood. They usually have higher yield than naturally regenerated forests. Thus, plantations can support economically viable wood production, enable forest conservation elsewere, help mitigate climate change by contributing to carbon sequestration and increase forest resilience and resistance to biotic and abiotic stressors. If yield of plantations is not as high as anticipated, then their use could generate important sustainability issues. There are still major gaps in our understanding of the factors that influence yield, even with respect to black spruce, white spruce, and jack pine, three of the most commonly planted tree species in northeastern North America. Our objective was to evaluate the yield of forest plantations of these species over a 416 000 km2 region that was representative of northeastern North American forests. Contrary to our prediction, realized yield of operational plantations was consistently lower than anticipated. Site index and competition both played a significant role in determining the yield of plantations. In the context of uncertain realized yield of operational plantations, we emphasize the necessity of relying on adaptive management to determine harvest levels that are compatible with sustainable management objectives. [ABSTRACT FROM AUTHOR]

Riparian buffer zones (RBZs) are an important instrument for environmental policies for water and biodiversity protection in managed forests. We investigate the variation of the cost of implementing RBZs within different property size classes across the size range of non-industrial forest owner properties in Southern Sweden. Using the Heureka PlanWise decision support system, we quantified the cost of setting aside RBZs or applying alternative management in them, as the relative loss of harvest volume and of net present value per property. We did this for multiple simulated as well as real-world property distributions. The variation of cost distribution among small properties was 4.2–6.9 times higher than among large properties. The interproperty cost inequality decreased non-linearly with increasing property size and levelled off from around 200 ha. We conclude that RBZs, due to the irregular distribution of streams, cause highly unequal financial consequences for owners, with some small property owners bearing a disproportionally high cost. This adds to previous studies showing how environmental considerations differentially affect property owners. We recommend decision makers to stimulate the uptake of RBZs by alleviating these inequalities between forest owners by including appropriate cost sharing or compensation mechanisms in their design. [ABSTRACT FROM AUTHOR]

Economies and livelihoods in the Caribbean strongly depend on the terrestrial and marine natural resource base. There are critical gaps in quantitative data and the contextual and compositional factors affecting perceptions of changes in ecosystems and natural resources. This paper used interview data from 441 households in Belize, Dominican Republic, and Suriname to explore the contextual and compositional determinants of perceptions of change in the quality of the terrestrial, coastal/marine environment and natural resources as a composite variable. The outcome variable comprised changes in fishing effort, marine and coastal environment, forest cover, agricultural land area, and soil fertility, and relationships with predictor variables were explored using univariate, bivariate, and three multivariate models. At the univariate level, most respondents in Belize and Suriname reported perceiving a significant increase in fishing effort (i.e. days and fuel spent at sea) and a decrease in forest cover, quality of the coastal/marine environment, area of agricultural land, and fertility and productivity of soils. Sex, marital status, household size, and years of experience were not significantly associated with the terrestrial variables and fishing effort. Sex was only significantly associated with the quality of the marine environment. At the multivariate level, the elderly, high school education, and household incomes were associated with a lower perception of the outcome variable. It is concluded that policy and interventions should strongly consider ethnicity and community, and improve education and household incomes to enhance perceptions of changes in the quality of the terrestrial and coastal/marine environment in the studied countries. [ABSTRACT FROM AUTHOR]

The relationship between primary productivity and diversity has been demonstrated across taxa and spatial scales, but for organisms with biphasic life cycles, little research has examined whether productivity of larval and adult environments influence each life stage independently, or whether productivity of one life stage's environment outweighs the influence of the other. Experimental work demonstrates that tadpoles of stream-breeding anurans can exhibit a top-down influence on aquatic primary productivity (APP), but few studies have sought evidence of a bottom-up influence of primary productivity on anuran abundance, species richness and community composition, as seen in other organisms. We examined aquatic and terrestrial primary productivity in two forest types in Borneo, along with amphibian abundance, species richness, and community composition at larval and adult stages, to determine whether there is evidence for a bottom-up influence of APP on tadpole abundance and species richness across streams, and the relative importance of aquatic and terrestrial primary productivity on larval and adult phases of anurans. We predicted that adult richness, abundance, and community composition would be influenced by terrestrial primary productivity, but that tadpole richness, abundance, and community composition would be influenced by APP. Contrary to expectations, we did not find evidence that primary productivity, or variation thereof, predicts anuran richness at larval or adult stages. Further, no measure of primary productivity or its variation was a significant predictor of adult abundance, or of adult or tadpole community composition. For tadpoles, we found that in areas with low terrestrial primary productivity, abundance was positively related to APP, but in areas with high terrestrial primary productivity, abundance was negatively related to APP, suggesting a bottom-up influence of primary productivity on abundance in secondary forest, and a top-down influence of tadpoles on primary productivity in primary forest. Additional data are needed to better understand the ecological interactions between terrestrial primary productivity, aquatic primary productivity, and tadpole abundance. [ABSTRACT FROM AUTHOR]

Forest canopy structural complexity (CSC) plays a crucial role in shaping forest ecosystem productivity and stability, but the precise nature of their relationships remains controversial. Here, we mapped the global distribution of forest CSC and revealed the factors influencing its distribution using worldwide light detection and ranging data. We find that forest CSC predominantly demonstrates significant positive relationships with forest ecosystem productivity and stability globally, although substantial variations exist among forest ecoregions. The effects of forest CSC on productivity and stability are the balanced results of biodiversity and resource availability, providing valuable insights for comprehending forest ecosystem functions. Managed forests are found to have lower CSC but more potent enhancing effects of forest CSC on ecosystem productivity and stability than intact forests, highlighting the urgent need to integrate forest CSC into the development of forest management plans for effective climate change mitigation.. [ABSTRACT FROM AUTHOR]

Forest growth varies across landscapes due to the intricate relationships between various environmental drivers and forest management. In this study, we analysed the variation of tree growth potential across a landscape scale and its relation to soil moisture. We hypothesised that soil moisture conditions drive landscape-level variation in site quality and that intermediate soil moisture conditions demonstrate the highest potential forest production. We used an age-independent difference model to estimate site quality in terms of maximum achievable tree height by measuring the relative change in Lorey's mean height for a five year period across 337 plots within a 68 km2 boreal landscape. We achieved wall-to-wall estimates of site quality by extrapolating the modelled relationship using repeated airborne laser scanning data collected in connection to the field surveys. We found a clear decrease in site quality under the highest soil moisture conditions. However, intermediate soil moisture conditions did not demonstrate clear site quality differences; this is most likely a result of the nature of the modelled soil moisture conditions and limitations connected to the site quality estimation. There was considerable unexplained variation in the modelled site quality both on the plot and landscape levels. We successfully demonstrated that there is a significant relationship between soil moisture conditions and site quality despite limitations associated with a short study period in a low productive region and the precision of airborne laser scanning measurements of mean height. [ABSTRACT FROM AUTHOR]

In forests, the amount and diversity of structural features with high value for biodiversity, such as large trees and dead wood, are affected by productivity, stand age, and forest management. For efficient conservation of forest biodiversity, it is essential to understand the combined effects of these drivers. We used data from the Swedish National Forest Inventory to study the combined effects of productivity, stand age, and management for wood production on structures with high value for biodiversity: tree species richness, large living trees, dead wood volume, and specific dead wood types. Forest management changed the relationship between productivity and amount or diversity of some of the structures. Most structures increased with productivity and stand age, but decreased due to management. The negative effect of management was greatest for structures occurring mainly in high-productivity forests, such as deciduous dead wood. Thus, biodiversity conservation should target high-productivity forests to preserve these structures. [ABSTRACT FROM AUTHOR]

Natural regeneration after mining activities depends largely on the soil seed bank (SSB) and aboveground vegetation (AGV) richness and composition. We evaluated the species diversity pattern of the SSB and AGV on soil and technosol across second‐growth Atlantic Forests (SGFs) after mining tailings deposition in Mariana, southeastern Brazil. Two second‐growth Atlantic seasonal semideciduous forests of different stand ages were selected: a 3‐year‐old stand of SGF re‐growing on tailings (SGF tailings) and a 30‐year‐old stand of native reference forest not affected by tailings (SGF nontailings). Overall, the results showed significant differences in forest attributes (species richness and composition) in the SSB and AGV between the two forest patches evaluated (SGF tailings and SGF nontailings). Moreover, both nonzoochoric and zoochoric dispersed species of AGV showed significant differences between second‐growth forests, with higher variability of community‐weighted mean in SGF tailings. The result shows smaller differences in species richness between forest types for both SBB (ranging 85 and 90 species) and AGV (~55 species). Despite the time difference between the secondary forest and the absence of zoochoric species in the tailings seed bank, the AGV that are re‐growing on mining tailings presented a high proportion of zoochoric species. This pattern of species richness and community composition variability observed in the technosol seed bank, and AGV that are re‐growing after the deposition of mining tailings are important recovery indicators for plant communities affected. [ABSTRACT FROM AUTHOR]

Short-term experimental studies provided evidence that plant diversity increases ecosystem resilience and resistance to drought events, suggesting diversity to serve as a nature-based solution to address climate change. However, it remains unclear whether the effects of diversity are momentary or still hold over the long term in natural forests to ensure that the sustainability of carbon sinks. By analyzing 57 years of inventory data from dryland forests in Canada, we show that productivity of dryland forests decreased at an average rate of 1.3% per decade, in concert with the temporally increasing temperature and decreasing water availability. Increasing functional trait diversity from its minimum (monocultures) to maximum value increased productivity by 13%. Our results demonstrate the potential role of tree functional trait diversity in alleviating climate change impacts on dryland forests. While recognizing that nature-based climate mitigation (e.g., planting trees) can only be partial solutions, their long-term (decadal) efficacy can be improved by enhancing functional trait diversity across the forest community. [ABSTRACT FROM AUTHOR]

Preplaced aggregate concrete (PAC) also known as two-stage concrete (TSC) is widely used in construction engineering for various applications. To produce PAC, a mixture of Portland cement, sand, and admixtures is injected into a mold subsequent to the deposition of coarse aggregate. This process complicates the prediction of compressive strength (CS), demanding thorough investigation. Consequently, the emphasis of this study is on enhancing the comprehension of PAC compressive strength using machine learning models. Thirteen models are evaluated with 261 data points and eleven input variables. The result depicts that xgboost demonstrates exceptional accuracy with a correlation coefficient of 0.9791 and a normalized coefficient of determination (R2) of 0.9583. Moreover, Gradient boosting (GB) and Cat boost (CB) also perform well due to its robust performance. In addition, Adaboost, Voting regressor, and Random forest yield precise predictions with low mean absolute error (MAE) and root mean square error (RMSE) values. The sensitivity analysis (SA) reveals the significant impact of key input parameters on overall model sensitivity. Notably, gravel takes the lead with a substantial 44.7% contribution, followed by sand at 19.5%, cement at 15.6%, and Fly ash and GGBS at 5.9% and 5.1%, respectively. The best fit model i.e., XG-Boost model, was employed for SHAP analysis to assess the relative importance of contributing attributes and optimize input variables. The SHAP analysis unveiled the water-to-binder (W/B) ratio, superplasticizer, and gravel as the most significant factors influencing the CS of PAC. Furthermore, graphical user interface (GUI) have been developed for practical applications in predicting concrete strength. This simplifies the process and offers a valuable tool for leveraging the model's potential in the field of civil engineering. This comprehensive evaluation provides valuable insights to researchers and practitioners, empowering them to make informed choices in predicting PAC compressive strength in construction projects. By enhancing the reliability and applicability of predictive models, this study contributes to the field of preplaced aggregate concrete strength prediction. [ABSTRACT FROM AUTHOR]

The relative importance of abiotic and biotic factors in shaping forest biomass stocks and fluxes remains a controversial issue. Here, using data gathered from 39 1 ha plots located in flooded and terra firme mature tropical lowland forests of the Amazon and Orinoquia regions of Colombia, we evaluated the importance of climate, soil fertility, and flooding, as well as tree taxonomic/phylogenetic diversity and forest structural properties, in determining the aboveground biomass stocks (AGB; Mg ha−1) and aboveground woody productivity (AWP; Mg ha−1 year−1). Using information‐theoretic multimodel inference and variance partitioning we found that forest structural features such as the number of trees with diameter at breast height ≥ 70 cm, and wood density, are the main drivers of variation in AGB. However, taxonomic diversity also contributes to AGB because it is associated with more large trees in these forests. In contrast, the key drivers of AWP in these forests were soil P and Mg concentrations, with no significant effects of diversity indices. These findings emphasize the need to include major soil cations other than N and P (e.g. Mg) in experimental studies to improve our understanding about the extent to which soil fertility can modulate increases in forest AWP due to climate change. Terra firme forests had higher AGB stocks than flooded forests, but both had similar AWP; and we found similar results for the drivers of AGB and AWP between flooded and terra firme forests. Our results provide limited evidence for strong effects of plant diversity on AGB or AWP. Therefore, we call for caution on generalizations of nature‐based initiatives aiming to preserve diversity based on maximizing carbon stocks and productivity, due to the complex nature of the processes controlling carbon accumulation and carbon fluxes in tropical forests. [ABSTRACT FROM AUTHOR]

Quantitative gait analysis is important for understanding the non-typical walking patterns associated with mobility impairments. Conventional linear statistical methods and machine learning (ML) models are commonly used to assess gait performance and related changes in the gait parameters. Nonetheless, explainable machine learning provides an alternative technique for distinguishing the significant and influential gait changes stemming from a given intervention. The goal of this work was to demonstrate the use of explainable ML models in gait analysis for prosthetic rehabilitation in both population- and sample-based interpretability analyses. Models were developed to classify amputee gait with two types of prosthetic knee joints. Sagittal plane gait patterns of 21 individuals with unilateral transfemoral amputations were video-recorded and 19 spatiotemporal and kinematic gait parameters were extracted and included in the models. Four ML models—logistic regression, support vector machine, random forest, and LightGBM—were assessed and tested for accuracy and precision. The Shapley Additive exPlanations (SHAP) framework was applied to examine global and local interpretability. Random Forest yielded the highest classification accuracy (98.3%). The SHAP framework quantified the level of influence of each gait parameter in the models where knee flexion-related parameters were found the most influential factors in yielding the outcomes of the models. The sample-based explainable ML provided additional insights over the population-based analyses, including an understanding of the effect of the knee type on the walking style of a specific sample, and whether or not it agreed with global interpretations. It was concluded that explainable ML models can be powerful tools for the assessment of gait-related clinical interventions, revealing important parameters that may be overlooked using conventional statistical methods. [ABSTRACT FROM AUTHOR]

Unmodified forests are increasingly rare worldwide, with forestry a major contributor to habitat modification. Extending conservation practices beyond protected areas is important to conserve forest ecosystems.We investigate the response of native mammalian carnivores (both Order Carnivora and Family Dasyuridae) to production forests globally, including harvested native forest and timber plantations. We examine how carnivores recorded in production forests use these forests versus other land uses, particularly native and/or unharvested forest; how habitat use relates to threatened status, body size, diet and harvesting method; carnivore responses to habitat features within production forests; and carnivore denning, breeding and predation behaviour in production forests.We review 294 studies recording 132 carnivore species in production forests. Carnivores generally show higher use of unharvested native forests and lower use of agricultural land than production forests. Threatened species and large carnivores respond more negatively to production forests than non‐threatened species and small carnivores respectively. Hypercarnivores respond more negatively than omnivores to plantations compared to native forest, with no difference in the use of harvested and unharvested native forest between these dietary groups.Notably, a high proportion of carnivore species use clearfelled more than unharvested native forest. In forest with partial harvesting or reduced‐impact logging, most species show no difference in use between harvested and unharvested forest.Carnivores generally respond positively to habitat features such as riparian areas and coarse woody debris. Several carnivores were recorded denning and breeding in production forests. Production forests often influence the prey availability, hunting success and diet of carnivores.We show that many carnivores use production forests, and how they respond to production forestry varies with species traits and conservation status. We recommend that production forests are managed as valuable carnivore habitat, and highlight strategies to enhance the use of these forests by carnivores. [ABSTRACT FROM AUTHOR]

The metabarcoding of prokaryotic and fungal (Ascomycota only) ribosomal DNA was used to describe the microbial communities in soils of a remnant equatorial rainforest, maize–bean intercrop, and sugarcane in western Kenya. Cropping systems influenced the microbial community composition and functional traits (energy source and nutrient cycling) of bulk soil in each crop. Microbial richness and diversity tended to increase with cultivation intensity. The soil of the maize–bean intercrop had lower percentages and sugarcane had higher percentages of unique amplicon sequence variants of both bacteria and fungi compared to the remnant forest. Functional traits were altered by cultivation intensity. Compared to remnant forest soils, maize–bean intercrop soil had lower percentages of aerobic chemoheterotrophic bacteria and higher percentages of N-cycling bacteria, while sugarcane had higher percentages of aerobic chemoheterotrophic bacteria and lower percentages of N-cycling bacteria. In the face of increasing forest loss and pressures for agricultural productivity, this landscape provides a rich site for studying the impacts of cropping systems on soil health. [ABSTRACT FROM AUTHOR]

Solar radiation is scattered by cloud cover, aerosols and other particles in the atmosphere, all of which are affected by global changes. Furthermore, the diffuse fraction of solar radiation is increased by more frequent forest fires and likewise would be if climate interventions such as stratospheric aerosol injection were adopted. Forest ecosystem studies predict that an increase in diffuse radiation would result in higher productivity, but ecophysiological data are required to identify the processes responsible within the forest canopy. In our study, the response of a boreal forest to direct, diffuse and heterogeneous solar radiation conditions was examined during the daytime in the growing season to determine how carbon uptake is affected by radiation conditions at different scales. A 10‐year data set of ecosystem, shoot and forest floor vegetation carbon and water‐flux data was examined. Ecosystem‐level carbon assimilation was higher under diffuse radiation conditions in comparison with direct radiation conditions at equivalent total photosynthetically active radiation (PAR). This was driven by both an increase in shoot and forest floor vegetation photosynthetic rate. Most notably, ecosystem‐scale productivity was strongly related to the absolute amount of diffuse PAR, since it integrates both changes in total PAR and diffuse fraction. This finding provides a gateway to explore the processes by which absolute diffuse PAR enhances productivity, and the long‐term persistence of this effect under scenarios of higher global diffuse radiation. [ABSTRACT FROM AUTHOR]

Understanding the relationship between biodiversity and productivity can be advanced by improving metrics used to quantify biodiversity. Structural diversity, that is, variation of size and form of plant organs, is an emerging biodiversity metric. However, compared with the other biodiversity metrics, its relative importance in specific components of forest productivity, for example, recruitment of new individuals, biomass net change after accounting for mortality, is largely unknown, particularly across a large spatial scale with multiple influential gradients. To address the knowledge gap, we used USDA Forest Service Forest Inventory and Analysis (FIA) data across the southcentral USA from 2008 to 2017. We calculated forest biomass increments due to recruitment and growth and net change in biomass. Then, we quantified the effects of a range of abiotic and biotic variables on the biomass increments and net change. Our results showed that (1) Structural diversity was negatively associated with the two biomass increments and net change in biomass. The negative effects were supported by increased occurrences of insects and diseases with greater structural diversity. (2) Compared with species and functional diversity, structural diversity showed a better association with biomass increments and net change, suggested by its larger absolute values of standardized coefficients, and the effects of structural diversity were negative in contrast to species diversity. (3) The effects of structural diversity, stand age, and elevation differed between natural and planted forests that may stem from the differences in stand development and species composition between the two forest types. Together, structural diversity may represent an important dimension of biodiversity impacts on plant productivity, which could be related to the exacerbated disturbances with greater structural diversity. [ABSTRACT FROM AUTHOR]

Biotic and abiotic conditions have been found to strongly influence how biodiversity affects ecosystem functioning in forests. This context dependency of biodiversity‐productivity relationships in real‐world ecosystems may be shaped by the biogeographic context via deep‐time processes acting on the size and composition of the species pool such as dispersal limitation, environmental filtering, speciation and invasibility. However, the role of the biogeographic context in shaping multifaceted biodiversity and forest productivity relationships remains uncertain.Using data from the Spanish National Forest Inventory in climatically similar forests on the Canary Islands (637 plots) and mainland Spain (1434 plots), we investigate the extent to which above‐ground productivity is determined by ecological and evolutionary processes associated with the biogeographic context. We used structural equation models to test the drivers of above‐ground productivity in both contexts, that operate via multifaceted tree diversity (taxonomic, phylogenetic, and functional diversity) or alternative mechanisms, that is environmental conditions, non‐native species, and the number of trees.Our results show that mainland and island forests exhibit similar levels of productivity, yet island forests display overall lower multifaceted diversity. We found that the number of trees increased multifaceted diversity and also increased productivity directly and via their effects on phylogenetic diversity in both mainland and island forests. Further, non‐native species increased productivity in island forests.Synthesis: Our results suggest that multifaceted diversity, by capturing the diversity of evolutionary history, contributes to elucidating diversity‐productivity relationships in mainland and island forests that could not be detected by taxonomic diversity alone. By filling empty niches in island forests, we find that non‐native species are fundamentally altering ecosystem functioning on islands and thus, reveal how biogeographic context can shape biodiversity‐productivity relationships. [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]

Agroecology is identified as an important solution to increase the sustainability of agricultural and food systems. Despite the increasing number of publications assessing the socio-economic outcomes of agroecology, very few studies have consolidated the scattered results obtained on various case studies. This paper provides new insights by consolidating evidence on the varied socio-economic effects of agroecology across a large number of cases at a global level. To this purpose, we used a rapid review methodology, screening more than 13,000 publications to retrieve evidence on the socio-economic outcomes of the implementation of agroecological practices. The results of the review indicate that (1) agroecological practices are associated more often with positive socio-economic outcomes across the broad range of evaluated metrics (51% positive, 30% negative, 10% neutral, and 9% inconclusive outcomes); (2) the socio-economic metrics associated with financial capital represent the vast majority of evaluated metrics (83% of total) and are affected positively in a large share of cases (53%), due to favourable outcomes on income, revenues, productivity and efficiency; (3) human capital metrics (16%) are associated with a larger number of negative outcomes (46% versus 38% positive), due to higher labour requirements and costs that are however partly compensated by an overall greater number of positive outcomes on labour productivity (55%); and (4) the results vary depending on the agroecological practice assessed; e.g. for agroforestry, we identify 53% positive outcomes while for cropping system diversification 35%. These results indicate an overall favourable potential for farms to benefit from a positive socio-economic performance with the use of agroecological practices. Yet, the magnitude, temporal aspects, and success factors related to these outcomes, as well as the trade-offs between them, and the system-level effects of an agroecological transition are to be further assessed, since they can have an important influence on the performance of individual farms. [ABSTRACT FROM AUTHOR]

The current study assessed the association of eucalyptus-tree spacing with forest growth and yield, as well as with the floristic composition, diversity and yield of natural grassland grown in silvopastoral systems in Pampa biome. Data were collected in six family cattle-ranching area in Bagé County (RS). The effect of two different genetic materials (seminal-origin Eucalyptus dunnii plant and one Eucalyptus grandis clone) on shading features of plants grown in 3 planting-spacing dimensions (625, 312 and 208 trees ha-1) was assessed, as well as their association with herbaceous extract (bare soil; green cover; forage dry matter; floristic composition; species richness; and grass, legumes and winter - and summer-growth species rates) and forestry (litter accumulation, diameter at breast height, total height and volume per hectare) variables. Planting carried out at the highest tree density (625 trees ha-1) has increased forest yield. However, it reduced green cover, herbaceous extract dry-matter yield and species richness, mainly in grasses and legumes with greater forage potential. Conversely, it is possible combining forestry and animal yield to the preservation of native forage species at low tree densities (204 to 312 trees ha-1). [ABSTRACT FROM AUTHOR]

Tree species composition is known to influence forest productivity, but its effect on forest resilience to disturbances such as storms remains largely unexplored. Furthermore, climate is likely to influence forest resilience directly but also to influence the effect of tree species composition on resilience. In Europe, storm‐induced tree mortality is currently increasing across all climatic biomes. Understanding the drivers of forest resilience to storms and its consistency across climates appears to be crucial for predicting the consequences of climate change for European forests.In this study, we used a simulation approach with an integral projection model calibrated with National Forest Inventory (NFI) data at the European scale. We restricted our simulations to tree species assemblages observed in the NFI data, covering a species diversity gradient nested within a climate gradient. We quantified functional diversity and the mean position of each species assemblage at equilibrium on two functional axis: (i) conservative versus fast growing and (ii) low versus high recruitment. We disturbed each species assemblage from equilibrium using species‐specific storm disturbance mortality probabilities and quantified the assemblages' resistance (inverse of immediate basal area loss), recovery (slope of post‐disturbance increase in basal area) and resilience (inverse of the cumulative deviation of basal area from the undisturbed state).We found that on average, species‐rich assemblages had higher recovery and resilience to storm disturbance, while functional diversity improved resistance and recovery. When analysing how this effect varied with climate, we found that diversity significantly increased resistance and resilience in the climatic margins only. Finally, we found that storm resilience was also driven by species mean position along both functional axes. In particular, the conservative‐productive axis had an effect two to three times greater than diversity: forests dominated by conservative species were more resistant and resilient, but had lower recovery than species assemblages dominated by fast‐growing species.Taken together, these results show that climate and tree species composition interact to control the ability of forests to resist and recover from a storm disturbance through both direct and indirect effects. As such, our findings should help to better anticipate climate change consequences for forest ecosystems. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

With increasing demands on the quality and quantity of produced biomass, as the main element of the knowledge-based economy, people and the issue of safety and health protection at work are coming to the fore. The aim of the work is the synthesis and overview of the results of the analysis of the health and safety risks of the production of forest biomass in various production phases, starting with its cultivation, through the harvesting production and transport process, up to the issue of its safe storage until it is used for the production of primary energy. Based on the analyzed overview of the existing risks in the production and storage of biomass, it can be concluded that the largest number of works is dedicated to the technological process of storage and consumption of the produced forms of biomass. Of the risks in this phase, the largest number of works is devoted to the risks of the production of spores of phytopathogens and fungi threatening human health. Further research should be primarily oriented toward creating models and modeling the processes of the emergence of these risk factors and the dynamics of their growth. [ABSTRACT FROM AUTHOR]

In the context of global warming, low-carbon economy has attracted more and more countries' attention. Using second-generation unit root CIPS test and mean group (MG) estimation, we examined the impact of CO2 emissions and economic loss on forest productivity with panel data on 30 Chinese provinces from 2004 to 2020.The results showed that CO2 emissions and economic loss had significant negative impacts on it, technical innovation had positive impacts on it, and the share of secondary industry had negative impacts on it. Regarding regional heterogeneity, CO2 emissions in west China had the greatest impact on forest productivity, followed by east China. The coefficients of economic loss in west, east and middle China were all negative, but those in east and middle China did not pass significance test. The coefficients of technical innovation in east and west China were positive, with the coefficient in east China not passing significance test. In order to improve forest productivity and achieve carbon neutrality, it is necessary to reduce CO2 emissions, curb economic losses caused by factors like environmental pollution, natural disasters, geological disasters and forest fires, improve technological innovation, promote industrial upgrade, and implement differentiated policies based on local conditions. [ABSTRACT FROM AUTHOR]

Rapid biodiversity losses under global climate change threaten forest ecosystem functions. However, our understanding of the patterns and drivers of multiple ecosystem functions across biodiversity gradients remains equivocal. To address this important knowledge gap, we measured simultaneous responses of multiple ecosystem functions (nutrient cycling, soil carbon stocks, organic matter decomposition, plant productivity) to a tree species richness gradient of 1, 4, 8, 16, and 32 species in a young subtropical forest. We found that tree species richness had negligible effects on nutrient cycling, organic matter decomposition, and plant productivity, but soil carbon stocks and ecosystem multifunctionality significantly increased with tree species richness. Linear mixed‐effect models showed that soil organisms, particularly arbuscular mycorrhizal fungi (AMF) and soil nematodes, elicited the greatest relative effects on ecosystem multifunctionality. Structural equation models revealed indirect effects of tree species richness on ecosystem multifunctionality mediated by trophic interactions in soil micro‐food webs. Specifically, we found a significant negative effect of gram‐positive bacteria on soil nematode abundance (a top‐down effect), and a significant positive effect of AMF biomass on soil nematode abundance (a bottom‐up effect). Overall, our study emphasizes the significance of a multitrophic perspective in elucidating biodiversity‐multifunctionality relationships and highlights the conservation of functioning soil micro‐food webs to maintain multiple ecosystem functions. [ABSTRACT FROM AUTHOR]

Worldwide, amphibians are experiencing high rates of decline. Large-scale, long-term studies of amphibians are crucial for uncovering potential causes of the declines; however, such long-term studies remain rare, particularly for salamanders. In this study, we monitored populations of Spotted Salamanders (Ambystoma maculatum) in 90 Connecticut, USA, ponds. Populations were divided between an inland, undeveloped landscape monitored for up to 23 yr and a coastal, developed landscape monitored for up to 9 yr. We measured the density of egg masses (number of egg masses per unit of search effort) each year at each pond for a total of 1392 pond-years of sampling effort and asked how egg mass densities and breeding probability relate to local environmental and climatic conditions. In the undeveloped landscape, average egg mass densities have declined by ∼30% over the course of 2 decades. The presence of salamander breeding activity was positively associated with spring pond depth, and pond depth itself has declined by ∼20% during the survey period. We also found that egg mass density was related to road proximity and developed land cover: egg mass densities tended to be higher in ponds near roads and in ponds with less development within a 200-m buffer. In the developed landscape, egg mass densities showed a nonsignificant declining trend from 2014 to 2022 and salamander breeding activity was positively associated with higher canopy cover and larger pond surface area. Our findings suggest that even in a protected landscape with increasing forest cover, spotted salamander egg mass densities are declining at a rate of 1.6%/yr. Decreasing pond depths are likely linked to decreased water yield as forests grow, which could affect pond hydroperiods (aquatic larval habitat) as well as forest soil moisture levels (adult habitat). Overall, increasing development may continue to negatively affect habitat of Spotted Salamanders and it is possible that forest maturation also has a negative influence on salamanders—an effect not documented previously. [ABSTRACT FROM AUTHOR]

Temperate forests, especially those in the densely populated regions of the world, are experiencing increasing levels of habitat degradation and biological impoverishment due to subtle but pervasive chronic anthropogenic disturbances including frequent and continuous grazing and extraction of non‐timber forest products. However, the effects of these subtle, chronic disturbances on the biodiversity‐productivity relationship have rarely been examined especially in forests at different development stages. Accordingly, this study explores how chronic anthropogenic disturbance affects the relationship between tree species diversity and forest productivity at different stand development stages in a large temperate forest region.We used the human footprint index as a proxy for chronic human disturbance. Hierarchical Bayesian models were employed to assess the effects of chronic human disturbance on the relationship between tree diversity and forest productivity across different stand age. Several measures of diversity were employed, including taxonomic, functional and phylogenetic diversity.Forest productivity consistently increased with taxonomic, functional and phylogenetic biodiversity; these biodiversity facets were the main drivers of forest productivity compared to stand age, chronic human disturbance and climate. However, the magnitude at which productivity increases with the increments of taxonomic and functional diversity diminishes with the increasing chronic disturbance, especially in younger stands. The effects of phylogenetic diversity on productivity did not vary with chronic disturbance, regardless of stand age.Synthesis and applications: Chronic human disturbance in a large temperate forest region reduces the increase in community productivity due to different facets of biodiversity, especially in young forests. The evidence suggests that the mitigation of chronic human disturbance and the conservation of biodiversity will be effective in sustaining essential ecosystem functions. [ABSTRACT FROM AUTHOR]

There is growing interest in continuous cover forestry in Sweden. The historical domination of even-aged forest management means there is a need to focus on methods for transforming even-aged to uneven-aged stands. Practical conversion management today is highly adaptive, and the possibility of failures, such as persistent lack of tree recruitment, must be allowed for. We used simulations to evaluate various scenarios in which conversion management is introduced at different development stages in even-aged stands and then abandoned in favour of clear-felling. A shift towards an inverse J-shaped diameter distribution at the end of the simulations was most evident in northern Sweden and with an early introduction of conversion forestry. The largest losses were incurred in a scenario where the conversion management started with removing larger trees at pre-commercial thinning: it reduced the volume of production by up to 25% and, if clear-felled, resulted in a lower land expectation value than conventional management. Earlier decision to abandon conversion management reduced the losses, but the effect of timing was minor. In summary, the results indicate that conversion management could be started and abandoned without any major economic loss during the timeframe of a normal rotation. [ABSTRACT FROM AUTHOR]

The decycling number ▽ (G) of a graph G is the smallest number of vertices whose deletion yields a forest. Bau and Beineke proved that κ(G) ≤ ▽(G) + 1 for every graph G, where κ(G) is the connectivity of G (Australas J Combin, 25:285-298, 2002). In this paper, we consider graphs with κ(G) = ▽(G)+1 and establish sufficient conditions for such graphs to be Hamiltonian, pancyclic and edge-Hamilton, respectively. To our knowledge, this is the first result studying Hamilton problem in terms of decycling number. It is well-known that determining the decycling number of a graph is equivalent to finding the greatest order of an induced forest and some sufficient conditions for Hamiltonian graphs are also sufficient for the existence of completely independent spanning trees. This paper may provide a new condition implying completely independent spanning trees. [ABSTRACT FROM AUTHOR]

Irrigation and fertilization are essential management practices for increasing forest productivity. They also impact the soil ecosystem and the microbial population. In order to examine the soil bacterial community composition and structure in response to irrigation and fertilization in a Eucalyptus plantations, a total of 20 soil samples collected from Eucalyptus plantations were analyzed using high-throughput sequencing. Experimental treatments consisting of control (CK, no irrigation or fertilization), fertilization only (F), irrigation only (W), and irrigation and fertilization (WF). The results showed a positive correlation between soil enzyme activities (urease, cellulase, and chitinase) and fertilization treatments. These enzyme activities were also significantly correlated with the diversity of soil bacterial communities in Eucalyptus plantations.. Bacteria diversity was considerably increased under irrigation and fertilization (W, F, and WF) treatments when compared with the CK treatment. Additionally, the soil bacterial richness was increased in the Eucalyptus plantations soil under irrigation (W and WF) treatments. The Acidobacteria (38.92–47.9%), Proteobacteria (20.50–28.30%), and Chloroflexi (13.88–15.55%) were the predominant phyla found in the Eucalyptus plantations soil. Specifically, compared to the CK treatment, the relative abundance of Proteobacteria was considerably higher under the W, F, and WF treatments, while the relative abundance of Acidobacteria was considerably lower. The contents of total phosphorus, accessible potassium, and organic carbon in the soil were all positively associated with fertilization and irrigation treatments. Under the WF treatment, the abundance of bacteria associated with nitrogen and carbon metabolisms, enzyme activity, and soil nutrient contents showed an increase, indicating the positive impact of irrigation and fertilization on Eucalyptus plantations production. Collectively, these findings provide the scientific and managerial bases for improving the productivity of Eucalyptus plantations. [ABSTRACT FROM AUTHOR]

Forests are integral to the global land carbon sink, which has sequestered ~30% of anthropogenic carbon emissions over recent decades. The persistence of this sink depends on the balance of positive drivers that increase ecosystem carbon storage--e.g., CO2 fertilization--and negative drivers that decrease it--e.g., intensifying disturbances. The net response of forest productivity to these drivers is uncertain due to the challenge of separating their effects from background disturbance--regrowth dynamics. We fit non-linear models to US forest inventory data (113,806 plot remeasurements in non-plantation forests from ~ 1999 to 2020) to quantify productivity trends while accounting for stand age, tree mortality, and harvest. Productivity trends were generally positive in the eastern United States, where climate change has been mild, and negative in the western United States, where climate change has been more severe. Productivity declines in the western United States cannot be explained by increased mortality or harvest; these declines likely reflect adverse climate-change impacts on tree growth. In the eastern United States, where data were available to partition biomass change into age-dependent and age-independent components, forest maturation and increasing productivity (likely due, at least in part, to CO2 fertilization) contributed roughly equally to biomass carbon sinks. Thus, adverse effects of climate change appear to overwhelm any positive drivers in the water-limited forests of the western United States, whereas forest maturation and positive responses to age-independent drivers contribute to eastern US carbon sinks. The future land carbon balance of forests will likely depend on the geographic extent of drought and heat stress. [ABSTRACT FROM AUTHOR]

Tropospheric ozone significantly damages vegetation and reduces net primary productivity (NPP). We developed a stable linear NPP response model based on accumulated ozone exposure over a threshold of 40 parts per billion (ppb) (AOT40). We then estimated the effects of regional ozone damage on NPP for different vegetation types. The study suggests an average decrease in NPP of 24.7% due to ozone pollution in the North China Plain, similar to previous estimates ranging from 10.1% to 24.7%, with a maximum reduction exceeding 200 [g C m‐2 yr‐1] and more than 50%. Vegetation types such as broadleaf forests, needleleaf forest, crops, and grasses showed significant NPP decreases of 47.1%, 37.8%, 36.7%, and 44.6%, respectively. Declining NPP also had negative impacts on several Chinese crop species. Our work highlights the need for urgent and effective action to mitigate ozone pollution's substantial detrimental effects on ecosystem health and productivity. Plain Language Summary: Ozone pollution led to an average 25% decrease in net primary productivity in the North China Plain. This decline is consistent with previous estimates that ranged from 10% to 25%. Productivity of forest trees, crops, and grasses declined significantly, ranging from 36.7% to 47.1%. These results have implications for Chinese crops, as lower crop productivity can negatively affect crop yields. Our study highlights the urgent need for action to mitigate the detrimental effects of ozone pollution on ecosystem health and productivity. Key Points: We developed a stable model to estimate ozone impact on the productivity of plants'Ozone pollution resulted in an average decline in productivity of 25% per year in all ecosystem types in the North China Plain regionOzone pollution led to net primary productivity declines in forest, crops, and grasses, with reductions ranging from 36.7% to 47.1% [ABSTRACT FROM AUTHOR]

The concept of forest productivity is biologically complex. In forest masses, it is indirectly estimated via dominant height growth models and site indices. The aim of this study was to develop a dominant height model for Gmelina arborea using data from 129 monitoring plots. 9 dynamic equations were generated from the Hossfeld and Bertalanffy-Richards theoretical models, which were individually fitted and cross-validated. Among the evaluated models, the Bertalanffy-Richards model (parameter c) stood out. This model showed a logical biological trend, with polymorphic curves and a unique asymptote. The selected model is an important tool for the management of G. arborea forest plantations in areas with site characteristics similar to those of this study. [ABSTRACT FROM AUTHOR]

The long‐term effects of intensive forest harvest on sensitive demographic stages of the American black bear (Ursus americanus) have been often overlooked. Much of Maine, USA, is covered in forests that are hospitable to bears and commercial timber harvest. To investigate the potential effects of differing intensities of disturbance on black bears, and on females with cubs particularly, we designed a large‐scale natural experiment with 197 motion‐sensitive camera sites dispersed over representative forest stands in northern and central Maine. Using multi‐state occupancy models, we distinguished the overall trends in space use by females with young versus adult bears without young. Forest disturbance at large spatial scales was positively associated with the probability of use for both demographic groups and the availability of hardwood trees was an additional important factor for habitat use by females with young. Our study illustrates the use of motion‐sensitive cameras to monitor and understand habitat use by distinct life‐history stages of animals living in human‐modified landscapes, and results indicate that managers can maintain black bear habitat in areas of active forest harvest by ensuring the availability of hardwood species. [ABSTRACT FROM AUTHOR]

Climate change adaptation and mitigation strategies (CCAMS) are changes to the management of production forests motivated by the need to mitigate climate change, or adapt production forests to climate change risks. Sweden is employing CCAMS with unclear implications for biodiversity and forest ecosystem services (ES). Here, we synthesized evidence from 51 published scientific reviews, to evaluate the potential implications for biodiversity and a range of provisioning, regulating, and cultural ES, from the adoption of CCAMS relative to standard forestry practice. The CCAMS assessed were the adoption of (i) mixed-species stands, (ii) continuous cover forestry, (iii) altered rotation lengths, (iv) conversion to introduced tree species, (v) logging residue extraction, (vi) stand fertilization, and (vii) altered ditching/draining practices. We highlight the complexity of biodiversity and ES outcomes, identify knowledge gaps, and emphasize the importance of evidence-based decision making and landscape-scale planning when navigating choices involving the widespread adoption of CCAMS. [ABSTRACT FROM AUTHOR]

Cuscus is marsgupials endemic to the eastern part of Indonesia. Populations and their habitats are under pressure due to deforestation, land clearing and massive utilization of forest resources. Studies on cuscus ecology have mainly focused on protected habitats or conservation areas. This study aims to identify and analyse populations and predict the distribution of cuscus in production forest area, which is PT Wijaya Sentosa. This study was conducted in November 2020 until January 2021 in several land cover categories. The methods used in this study were literature and secondary data studies, field observations using striptransect and camera trap techniques, interviews using purposive sampling techniques. This study found nine individual cuscuses from two families, namely Phalanger and Spilocuscus, as well as four species, namely ground cuscus (Phalanger gymnotis), spotted cuscus (Spilocuscus maculatus), Bohai cuscus (Spilocuscus rufoniger) and gray cuscus (Phalanger orientalis). Individual encounters were obtained from direct observation with transect lines and two cuscus individuals from camera traps. Ground cuscus (P. gymnotis) populations had the highest abundance and density, while spotted cuscus (S. maculatus) populations had the lowest values. The population structure was dominated by males and adult age classes, but no females and young age classes were found. Most cuscus was found alone on the observation path and was not found on every path. The distribution pattern of the cuscus population in the production forest of PT Wijaya Sentosa's concession is grouped/aggregated, based on the dispersion index value and the ratio of the value of variance to the mean value. The most common ground cuscus was found in the 2018 and around the 2013 logged-over areas (LOA). [ABSTRACT FROM AUTHOR]

The current biodiversity and climate crises highlight the need for efficient tools to monitor terrestrial ecosystems. Here, we provide evidence for the use of airborne eDNA analyses as a novel method for detecting terrestrial vertebrate communities in nature. Metabarcoding of 143 airborne eDNA samples collected during 3 days in a mixed forest in Denmark yielded 64 bird, mammal, fish and amphibian taxa, of which the detected 57 'wild' taxa represent over a quarter of the around 210 terrestrial vertebrates that occur in the overall area. We provide evidence for the spatial movement and temporal patterns of airborne eDNA and for the influence of weather conditions on vertebrate detections. This study demonstrates airborne eDNA for high‐resolution biomonitoring of vertebrates in terrestrial systems and elucidates its potential to guide global nature management and conservation efforts in the ongoing biodiversity crisis. see also the Perspective by David M. Lodge [ABSTRACT FROM AUTHOR]

Understanding the mechanisms underlying diversity–productivity relationships (DPRs) is crucial to mitigating the effects of forest biodiversity loss. Tree–tree interactions in diverse communities are fundamental in driving growth rates, potentially shaping the emergent DPRs, yet remain poorly explored. Here, using data from a large‐scale forest biodiversity experiment in subtropical China, we demonstrated that changes in individual tree productivity were driven by species‐specific pairwise interactions, with higher positive net pairwise interaction effects on trees in more diverse neighbourhoods. By perturbing the interactions strength from empirical data in simulations, we revealed that the positive differences between inter‐ and intra‐specific interactions were the critical determinant for the emergence of positive DPRs. Surprisingly, the condition for positive DPRs corresponded to the condition for coexistence. Our results thus provide a novel insight into how pairwise tree interactions regulate DPRs, with implications for identifying the tree mixtures with maximized productivity to guide forest restoration and reforestation efforts. [ABSTRACT FROM AUTHOR]

Determining the patterns of changes in the productivity of agricultural land in different growing areas in the zone of influence of State Protective Forest Belts (SPFB) is relevant due to the need to assess the future crop yield in fields with differences in geomorphological, soil, and climatic conditions in the research area. The object was to study the sowing of winter grain crops in fields mixed within the influence of State Protective Forest Belts. Materials and methods involved a research methodology based on the geoinformation analysis of the results of the decryption of actual satellite images, both to identify the distribution of cultivated fields located in the zone of influence of SPFB, and the state of crops on them. At the same time, the soil zonality of the research area was taken into account in view of the considerable length of forest strips. The assessment of the condition of winter grain crops as they move away from the planting was carried out using the NDVI vegetation index calculated from the high-resolution spectral channels of satellite images. Results and conclusions: based on the results of the research, a database of spatial data of the processed fields has been compiled. The grouping of fields was carried out both according to the similarity of the conditions of the places of cultivation of crops and by agricultural crops. Their placement and geomorphological parameters have been established. With the use of geoinformation technologies for groups of fields using statistical processing tools, the average values of the width and area of the selected zones of influence, as well as terrain parameters, were determined. During geoinformation mapping, data on the state of crops at the end of May were obtained based on the change in the NDVI index by field groupings in the zone of SPFB impact. These data are the basis for the forecast of crop yields, taking into account the spatial location of fields. [ABSTRACT FROM AUTHOR]

The rotation lengths of intensively managed production forests may be altered to achieve a variety of goals, with correspondingly implications for biodiversity. Here we consider the potential implications of shortened rotation times for biodiversity in planted monocultures of the two most common production tree species in Sweden, Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). To do so we surveyed bird, bryophyte, epiphytic lichen and vascular plant diversity in 80 and 55-year-old stands; stand ages which approximate present-day and potential future rotation lengths in this region respectively. We found clear differences in the species communities of the 55 compared to the 80-year-old stands for both understory species and epiphytes, but not for birds. Nevertheless, bird species richness was still highest in the 80-year-old Norway spruce dominated stands. Dead wood amount was also highest the 80-year-old Norway spruce stands. Highest species richness of epiphytic lichens was found in 80-year-old Scots pine stands. However, 55-year-old Scots pine stands had a higher understory species richness and diversity than the older Scots pine stands, including a larger number of open land species. The 80-year-old forest stands examined may be considered old with respect to production forest rotation lengths in Sweden but are relatively young when comparing stand ages of unmanaged natural forest stands. Nevertheless, our results indicate that shortening the rotation time of Scots pine and Norway spruce, in this part of Sweden from 80 to 55 years, could have important consequences for forest biodiversity. These consequences are primarily inferred from the likely implications from shortened rotations for lichens community composition and diversity in both Norway spruce and Scots pine stands, as well as impacts on understory plant species in Norway spruce stands. [ABSTRACT FROM AUTHOR]

Summary: Understanding how intra‐annual stem growth responds to atmospheric and soil conditions is essential for assessing the effects of climate extremes on forest productivity. In species‐poor forests, such understanding can be obtained by studying stem growth of the dominant species. Yet, in species‐rich (sub‐)tropical forests, it is unclear whether these responses are consistent among species.We monitored intra‐annual stem growth with high‐resolution dendrometers for 27 trees belonging to 14 species over 5 yr in a montane subtropical forest. We quantified diel and seasonal stem growth patterns, verified to what extent observed growth patterns coincide across species and analysed their main climatic drivers.We found very consistent intra‐annual growth patterns across species. Species varied in the rate but little in the timing of growth. Diel growth patterns revealed that – across species – trees mainly grew before dawn when vapour pressure deficit (VPD) was low. Within the year, trees mainly grew between May and August driven by temperature and VPD, but not by soil moisture.Our study reveals highly consistent stem growth patterns and climatic drivers at community level. Further studies are needed to verify whether these results hold across climates and forests, and whether they can be scaled up to estimate forest productivity. [ABSTRACT FROM AUTHOR]

Summary: Understanding the long‐term impact of projected climate change on tropical rainforests is critical given their central role in the Earth's system. Palaeoecological records can provide a valuable perspective on this problem. Here, we examine the effects of past climatic changes on the dominant forest type of Southeast Asia – lowland dipterocarp forest.We use a range of proxies extracted from a 1400‐yr‐old lacustrine sedimentary sequence from north‐eastern Philippines to determine long‐term vegetation responses of lowland dipterocarp forest, including its dominant tree group dipterocarps, to changes in precipitation, fire and nutrient availability over time.Our results show a positive relationship between dipterocarp pollen accumulation rates (PARs) and leaf wax hydrogen isotope values, which suggests a negative effect of drier conditions on dipterocarp abundance. Furthermore, we find a positive relationship between dipterocarp PARs and the proxy for phosphorus availability, which suggests phosphorus controls the productivity of these keystone trees on longer time scales. Other pollen taxa show widely varying relationships with the abiotic factors, demonstrating a high diversity of plant functional responses.Our findings provide novel insights into lowland dipterocarp forest responses to changing climatic conditions in the past and highlight potential impacts of future climate change on this globally important ecosystem. See also the Commentary on this article by Utteridge 240: 2176–2178. [ABSTRACT FROM AUTHOR]

Context: Protected areas are necessary to conserve biodiversity. Their locations, design and management can have major impacts on their effectiveness. In timber and pulpwood production forests of Victoria, Australia, Immediate Protection Areas (IPAs) were established by the Victorian Government to conserve biodiversity. IPA identification has overlooked much of 30 years of reserve selection science. This has resulted in poor selection of locations for protection, lack of attention to habitat suitability for target species, and a destructive past land use history that has eroded current habitat suitability. Aims: Our aim was to assess the suitability IPAs for threatened species, including Leadbeater's Possum (Gymnobelideus leadbeateri) and the Southern Greater Glider (Petauroides volans). Methods: We assessed aspects of effectiveness of IPAs for forest-dependent species of conservation concern. We compared the IPAs to a prioritised protected area network using Marxan accounting for past forest disturbances, including logging and high severity wildfires. Key results: We found IPAs failed to include the most suitable habitat areas, capturing only 11.7% of modelled habitat for Leadbeater's Possum and 5.3% for the Southern Greater Glider. Our analyses also revealed large parts of the IPA network had been clearcut logged, eroding habitat value for many species. Conclusions: Given IPAs do not protect substantial amounts of important habitat for threatened species such as Leadbeater's Possum and Southern Greater Glider, we conclude the current IPAs are unlikely to adequately protect biodiversity from logging. Implications. The IPAs need to be better designed to improve their effectiveness for biodiversity conservation. We provide recommendations on how this might be done. [ABSTRACT FROM AUTHOR]

Knowledge of ant and termite distribution and ecology is limited for transitional ecosystems in Central Africa. As ants and termites are the primary food for several insectivorous mammals, conservation strategies of threatened species can be strengthened with information on their key food resources. We investigated the ant and termite diversity of two protected areas located in a forest‐savanna transition zone in central Cameroon: Mpem et Djim National Park (MDNP) and Deng‐Deng National Park (DDNP). Ants and termites were collected along 100 line transects using pitfall and bait traps and hand‐sampling during major dry and rainy seasons in seven habitat types. Overall, 14,093 ant individuals representing 108 species, 29 genera, and six subfamilies were recorded. Myrmicinae was the most speciose subfamily in DDNP, while Formicinae dominated in MDNP. The most speciose genus was Crematogaster in both parks. Tapinoma melanocephalum and Pheidole sp. 3 were the most common species recorded in MDNP and DDNP respectively. Ant species richness was highest in near primary forest in DDNP, while richness was greater in the secondary forest of MDNP. Ant communities were more diversified in DDNP than in MDNP. In MDNP, the ant species richness and diversity were highest in the secondary forest and lowest in saltworks, while DDNP near primary forest species richness was highest and swamps lowest. A total of 89 species of termite representing 33 genera and nine subfamilies were recorded from a sample of 56,798 individuals. Termite species richness was similar at DDNP and MDNP. Macrotermitinae was the most common subfamily in both protected areas. The most species‐rich termite genus was Isognathotermes in both parks. Macrotermes amplus in DDNP and Reticulitermes sp. in MDNP respectively, were the most commonly sampled termite species. Near primary forest yielded more termite species in DDNP and MDNP than in other habitat types. Termites and ants' communities were more species‐rich and diversified in relatively closed‐canopy and low‐disturbed forest habitats than in savanna and flooded habitats. [ABSTRACT FROM AUTHOR]

This study aims to assess the effect of adding lignin waste, a by-product of bioethanol production from forest biomass, to asphalt concrete to improve its performance. After adjusting the lignin content based on preliminary Marshall tests, 20% of this by-product by mass of bitumen was added to the asphalt concrete blends via the dry method. This lignin content was suitable to the temperature was decreased 40 °C compared to the usual mixing temperature, thus allowing the production of warm-mix asphalt concrete (WMA) without any other additive. Tests on a gyratory compactor assessed the workability of the studied asphalt concrete, allowing us to obtain these findings. Moreover, lignin improved moisture damage and adhesion resistance between the binder film and the aggregate particles' surface. The behaviour at high temperatures was also enhanced, resulting in better resistance to permanent deformation. These promising laboratory results show us an opportunity to create value for this type of by-product in substituting commercial additives for asphalt concrete, such as organic wax or adhesion promoters, to allow the production of warm-mix asphalt concrete with improved properties. [ABSTRACT FROM AUTHOR]

Scientific consensus is that diverse tree species positively impact forest productivity, especially when species are functionally dissimilar. Under the complementarity hypothesis, differences in species traits reduce competition among neighboring tree species. However, while this relationship has been extensively studied at the community level, there is a lack of understanding regarding how individuals of different species specifically respond to a functionally dissimilar neighborhood. In this study, we used permanent plots from Quebec, Canada, and 19 focal tree species to test whether: (1) tree growth response to neighborhood dissimilarity varies with their identity and competition intensity, and (2) focal tree species' traits explain their response to neighborhood dissimilarity. We demonstrate that: tree growth is primarily influenced by competition, species identity, and their interactions, but that dissimilarity, alone and in interaction with the main drivers of tree growth, explains an additional 1.8% of the variation in species growth. Within this context, (1) most species' respond positively to neighborhood dissimilarity, with magnitude being species and competition dependent, and (2) focal tree traits partly explain these dependencies, with shade‐intolerant species benefiting most from dissimilar neighbors under high competition. Our study provides empirical support for the complementarity hypothesis, emphasizing the small but consistent positive effect of functional dissimilarity on tree growth in local neighborhoods. Our findings identify the species with the highest potential of benefiting from dissimilar neighbors but also demonstrate that the positive effect of neighborhood dissimilarity is not limited to a select few species with specific traits; rather, it is observed across a diverse range of species. The cumulative growth responses of individuals to functionally dissimilar neighbors may help explain the commonly observed higher productivity in more diverse communities. [ABSTRACT FROM AUTHOR]

Peculiarities of the compositionally pure larch stand formation following forest fires have been studied in the northern (Evenkia, middle course of the Nizhnyaya Tunguska River, 64°03′ N, 101°10′ E) and southern (Yermakovsky District, 52°23′ N, 93°33 ′ E) regions of Krasnoyarsk Krai. The structure, growth, and biological productivity of the forest restoration successions have been analyzed based on the materials from the sample plots. The highest phytomass value (in terms of total productivity) in larch stands is 1055.5 t abs. dry substances/ha at the age of 93 years. The structural ratio of the forest stands phytomass fractions naturally changes with an increase in their average age and density. An increase in the average age of a stand is associated with an increase in its above-ground and root phytomasses. At the same time, the relative proportion of the crown wood mass and needle mass in the total above-ground phytomass of a stand decreases. In 38-year-old larch forests, the proportion of crown mass is 18% and the share of stems is 82%. In 60-year-old forest stands, the total biomass of the crown wood and needles accounts for 14%, and the other 86% accounts for the stem weight. In the 93-year-old larch forest, the proportion of stem phytomass increases to 89%, and the proportion of combined crown wood and needles biomasses fall up to a minimum value of 11%. The maximum growth potential of the 56-year-old larch stands, according to the current increase in phytomass (in terms of total productivity), is realized at about 14.69 t abs. dry substances/ha per year. The young and middle-aged larch forests formed on the burnt areas have higher rates of growth and phytomass accumulation; in terms of the amount of fixed atmospheric carbon, they exceed the mature and overmature stands by more than two times. [ABSTRACT FROM AUTHOR]

The accuracy of vegetation indices (VIs) in estimating forest stand age is significantly inadequate due to insufficient consideration of the differences in the physiological functions of forest ecosystems, which limits the accuracy of carbon sink simulation. In this study, remote sensing inversion and mapping of forest stand age were carried out on the Loess Plateau under consideration of the remote sensing mechanism of VIs and the physiological function and canopy structure of the forest using multiple linear regression (MLR) and random forest (RF) models. The main conclusions are as follows: (1) The canopy reflectance of different forest stands has a significant change pattern, and the older the forest stands, the lower the NIR reflectance. The relationship between forest stands and red edge is the most significant, and r is 0.53, and the relationship between Simple Ratio Index (SR), near-infrared reflectance of vegetation (NIRv), normalized difference vegetation index (NDVI), Global Vegetation Index and forest stands is more nonlinear than linear. (2) Principal component analysis (PCA) of canopy spectral information shows that SR, NDVI and red edge (B5) could explain 98% of all spectral information. SR, NDVI and red edge (B5) were used to construct a multiple linear regression model and random forest (RF) algorithm model, and RF has high estimation accuracy (R2 = 0.63). (3) The accuracy of the model was evaluated using reference data, and it was found that the accuracy of the RF model (R2 = 0.63) was higher than that of the linear regression model (R2 = 0.61), but both models underestimated the forest stand age when the forest stand age was greater than 50a, which may be caused by the saturation of the reflectance of the old forest canopy. The RF model was used to generate the dataset of forest stand information in the Loess Plateau, and it was found that the forest is dominated by young forests (<20a), accounting for 38.26% of the forest area, and the average age of forests in the Loess Plateau is 56.1a. This study not only improves the method of forest stand age estimation, but also provides data support for vegetation construction in the Loess Plateau. [ABSTRACT FROM AUTHOR]