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Priming effects of soil organic matter decomposition are critical to determine carbon budget and turnover in soil. Yet, the overall direction and intensity of soil priming remains under debate. A second‐order meta‐analysis was performed with 9296‐paired observations from 363 primary studies to determine the intensity and general direction of priming effects depending on the compound type, nutrient availability, and ecosystem type. We found that fresh carbon inputs induced positive priming effects (+37%) in 97% of paired observations. Labile compounds induced larger priming effects (+73%) than complex organic compounds (+33%). Nutrients (e.g., N, P) added with organic compounds reduced the intensity of priming effects compared to compounds without N and P, reflecting "nutrient mining from soil organic matter" as one of the main mechanisms of priming effects. Notably, tundra, lakebeds, wetlands, and volcanic soils showed much larger priming effects (+125%) compared to soils under forests, croplands, and grasslands (+24...+32%). Our findings highlight that positive priming effects are predominant in most soils at a global scale. Optimizing strategies to incorporate fresh organic matter and nutrients is urgently needed to offset the priming‐induced accelerated organic carbon turnover and possible losses. [ABSTRACT FROM AUTHOR]

Our research assesses the effects of four forest species, namely, Swietenia macrophylla King, Swietenia mahagoni (L.) Jack., Pinus occidentalis Swartz, and Pinus caribaea Morelet var. Caribaea, on the soil and litter organic carbon (C) stocks, C dioxide equivalent balance (BCO2 Eq.) diurnal, and periodic dynamics beneath these species. Reforestation projects in the study region cover 1200, 543, 770, and 1152 hectares, respectively, with these four species being the most relevant in reforestation projects within the country. To determine the BCO2 Eq. per unit area, we compared the greenhouse gas (GHG) fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) expressed as CO2 Eq. units with the organic C stocks found in the mineral soil to a depth of 30 cm and in the forest litter. In four measurement periods over 18 months, we conducted field measurements in sixteen stands, four per species. Our results indicate that S. mahagoni emitted the lowest CO2 Eq., while S. macrophylla released the highest amount into the atmosphere. At the end of the 18 months, BCO2 Eq. from S. macrophylla soils was 299.70 metric tons ha−1 year−1, while for P. occidentalis, P. caribaea, and S. mahagoni, the corresponding quantities were 103.64, 146.41, and 72.34, respectively. All species showed a general upward pattern in soil respiration from September 2020 to March 2022. The average CO2 Eq. flux rates to the atmosphere were approximately 65.4, 51.1, and 75.9 percent higher in S. macrophylla soils compared to the respective rates of P. occidentalis, P. caribaea, and S. mahagoni. [ABSTRACT FROM AUTHOR]

[Display omitted] • Land use change profoundly impacts the migration of heavy metals (HMs) in the soil. • The comprehensive pollution index was in VGF>CVL>WSL>WDL. • Soil microbial and enzymatic activities did not directly affect HMs concentration. The accumulation of heavy metals (HMs) in soil has become a pressing global concern due to their persistent and non-degradable nature, resulting in the accumulation of toxic levels in the environment. In recent years, human activities have significantly altered land use patterns, leading to a marked increase in soil HM levels and subsequent land degradation. This research focused on four distinct land use patterns (vegetable fields (VGF), woodland (WDL), cultivated land (CVL), and wasteland (WSL)) commonly found in the Taojia River Basin, Hunan, China, which is facing severe HM pollution. Soil samples were collected from three different depths (0–10 cm, 10–20 cm, and 20–30 cm) to investigate HM distribution and intensity (cadmium (Cd), lead (Pb), copper (Cu), nickel (Ni), and zinc (Zn)), comprehensive soil pollution index, and their relationship with soil microbial and enzymatic activities. The results revealed that the Cd content exceeded the national standard for soil environmental quality, whereas concentrations of other HMs did not exceed the national standard across the four land use patterns. Most soil HMs were concentrated in the surface layer, with Cu, Pb, and Zn concentrations gradually decreasing with increasing soil depth. Conversely, Ni and Cd concentrations tended to increase with greater soil depth. There were significant positive correlations among HMs, indicating homogeneity among them. The pollution index across the HMs ranked as Cd > Ni > Zn > Cu and Pb, with land uses following the order of VGF (2.70) > CVL (2.12) > WSL (1.72) > WDL (1.63). Soil microbial and enzymatic activity was not the primary factor influencing HM concentration. The specific impacts of land use changes on soil HMs depend on management practices, local conditions, and the distribution characteristics of the HMs involved. [ABSTRACT FROM AUTHOR]

The availability of compostable plastic bags has increased greatly in the past few years, as it is perceived that this type of bags will be degraded after disposal. However, there are some knowledge gaps regarding the potential effects on the soil ecosystems. We assessed the rate of degradation of samples of four different types of commercial compostable bags in vermicomposting systems with the earthworm species Eisenia andrei. We also evaluated the biological response of E. andrei (survival and reproduction) to microplastics (MPs) from fragments of the plastic bags (Lepidium sativum L.) exposed to micronized plastic (L. sativum seedling emergence was not significantly affected; however, earthworm reproduction was affected, suggesting that although compostable, some of the formulations may potentially be toxic to soil fauna.

The availability of compostable plastic bags has increased greatly in the past few years, as it is perceived that this type of bags will be degraded after disposal. However, there are some knowledge gaps regarding the potential effects on the soil ecosystems. We assessed the rate of degradation of samples of four different types of commercial compostable bags in vermicomposting systems with the earthworm species Eisenia andrei. We also evaluated the biological response of E. andrei (survival and reproduction) to microplastics (MPs) from fragments of the plastic bags (<2000 µm) and assessed seedling emergence in common garden cress (Lepidium sativum L.) exposed to micronized plastic (<250 µm) and the respective leachate, following OECD and ISO guidelines, respectively. The rate of degradation differed significantly depending on the type of plastic rather than the substrate in the vermicomposting system. This finding suggests that the degradation process is more dependent on the microbial community colonizing the different plastic types than on earthworm activity. Regarding the biological response of the soil system, L. sativum seedling emergence was not significantly affected; however, earthworm reproduction was affected, suggesting that although compostable, some of the formulations may potentially be toxic to soil fauna. [ABSTRACT FROM AUTHOR]

In recent decades, the ubiquity of micro and nanoplastics (MNPs) pollution has emerged as a global concern due to its potential risks to both ecological and human health. The detrimental effects of MNPs have resulted in significant changes in the physicochemical and biological properties of terrestrial soil and benthic sediment. These alterations have led to a disrupted nutrient cycle, potential future climate hazards, and further impacts on ecosystem services. This review aims to discuss the possible origins, composition, abundance, life cycle, and transport processes of MNPs in aquatic and terrestrial ecosystems. It seeks to understand the potential ecological and human health risks associated with MNPs pollution and explores their implications for biodiversity conservation and ecosystem services. Moreover, this review highlights the advanced analytical techniques used to detect and quantify MNPs. It further suggests policy frameworks to combat this pollution in natural environments. The findings of this review are intended to assist environmentalists, microbiologists, hydrologists, and policymakers in identifying scientific gaps and pragmatic solutions to reduce MNPs pollution. Future research should investigate the intake mechanism and impact of MNPs on plants in different ecosystems, as well as their effects on food chains and human health. This will ensure that the ecological and human health risks associated with MNPs pollution can be timely mitigated. [ABSTRACT FROM AUTHOR]

Variation in herbivore pressure has often been predicted from patterns in plant traits considered as antiherbivore defences. Here, we tested whether spatial variation in field insect herbivory is associated with the variation in plant quality by conducting a meta‐analysis of 223 correlation coefficients between herbivory levels and the expression of selected plant traits. We found no overall correlation between herbivory and either concentrations of plant secondary metabolites or values of physical leaf traits. This result was due to both the large number of low correlations and the opposing directions of high correlations in individual studies. Field herbivory demonstrated a significant association only with nitrogen: herbivore pressure increased with an increase in nitrogen concentration in plant tissues. Thus, our meta‐analysis does not support either theoretical prediction, i.e., that plants possess high antiherbivore defences in localities with high herbivore pressure or that herbivory is low in localities where plant defences are high. We conclude that information about putative plant defences is insufficient to predict plant losses to insects in field conditions and that the only bottom‐up factor shaping spatial variation in insect herbivory is plant nutritive value. Our findings stress the need to improve a theory linking plant putative defences and herbivory. [ABSTRACT FROM AUTHOR]

Land use change (LUC) alters the global carbon (C) stock, but our estimation of the alteration remains uncertain and is a major impediment to predicting the global C cycle. The uncertainty is partly due to the limited number and geographical bias of observations, and limited exploration of its predictors. Here we generated a comprehensive global database of 5,980 observations from 790 articles. The number of sites evaluated is at least seven times larger than in previous meta‐analyses. Our constrained estimates of different LUC's effects on soil organic C (SOC) and their variations across global climates reveal underestimation/overestimation in previous estimates. Converting forests and grasslands to croplands reduced SOC by 24.5% ± 1.53% (−11.03 ± 1.06 Mg ha−1) and 22.7% ± 1.22% (−8.09 ± 0.67 Mg ha−1), while 28.0% ± 1.56% (4.46 ± 0.42 Mg ha−1) and 33.5% ± 1.68% (5.8 ± 0.38 Mg ha−1) increases, respectively, were obtained in the reverse processes. Converting forests to grasslands decreased SOC by 2.1% ± 1.22% (−1.13 ± 0.44 Mg ha−1), while the reverse process increased SOC by 18.6% ± 1.73% (3.31 ± 0.51 Mg ha−1). Modeled relative importance of 10 drivers of LUC's impact on SOC revealed that higher initial SOC (iSOC) does not solely determine SOC loss in SOC‐negative LUC scenarios as previously proposed. Across four decades, reconverting croplands to forests and grasslands recovered only 49.5% (6.1 ± 0.51 Mg ha−1) and 75.3% (7.0 ± 0.38 Mg ha−1) of the iSOC, respectively, indicating the need for protecting C‐rich ecosystems. Our global data set advances information on LUC's effect on SOC and can be valuable to constrain Earth system models to reliably estimate global SOC stocks and plan climate change mitigation strategies. Plain Language Summary: Land use change (LUC) could increase or decrease the global soil organic carbon (SOC) stock and affect carbon cycling and climate change, but estimating its effect size is the most uncertain aspect of the global carbon cycle. Available estimates vary among studies, most of which often use few observations that do not cover most global regions. To provide more accurate estimates of different LUC types' effects on SOC, we compiled a comprehensive database that contains 5,980 observations across all global regions; and revealed that previous studies have underestimated/overestimated these effects. We modeled the predictors of SOC change and found that previous conclusions that higher initial SOC is the main reason for higher organic carbon loss under negative LUC scenarios were inexact. We show that land use practices aimed at restoring SOC could only recover part of the amount lost during similar time frames; hence, it is important to protect carbon‐rich ecosystems. Our study provides robust estimates of LUC's effect on SOC and provides data sets that can reliably assess and model the global carbon cycle and plan strategies for controlling global climate change. Key Points: Comprehensive global database advances robust estimates of land use change's (LUCs) effect on soil organic carbon (SOC) vital for Earth system modelingHigher initial SOC does not solely control rapid SOC loss in carbon‐negative LUC as often proposedDespite SOC buildup in the past four decades, the amount lost cannot be regained by restoration during similar time frames [ABSTRACT FROM AUTHOR]

Micro(nano)plastics (MNPs) are pervasive pollutants posing significant environmental and health risks. Selecting appropriate sentinel species to assess MNPs in terrestrial and aquatic environments involves considering factors such as species behavior, habitat, exposure pathways, and the feasibility of sampling. For these reasons, it was imperative to launch a virtual special issue (VSI) in Ecological Indicators. This editorial summarizes the contributions submitted to the VSI, which invited research on bioindicators of MNPs, including sampling protocols, monitoring strategies, and analytical methods, to advance our understanding and management of plastic pollution. The VSI received a total of 12 contributions from four countries, with a significant majority originating from Italy. To present the contributions, we have organized the sections into original articles and reviews. The original articles are further divided into sections on the occurrence of MNPs in biotic and abiotic compartments, the selection of bioindicators, and the effects and risk assessment of MPs. The reviews are categorized based on their focus on aquatic and terrestrial ecosystems. Future ecotoxicology studies should select bioindicators based on exposure to MNPs, conservation status, ecological roles, and human consumption.

Through their rooting profiles and water demands, plants affect the distribution of water in the soil profile. Simultaneously, soil water content controls plant development and interactions within and between plant communities. These plant-soil water feedbacks might vary across plant communities with different rooting depths and species composition. In semiarid environments, understanding these differences will be essential to predict how ecosystems will respond to drought, which may become more frequent and severe with climate change. In this study, we tested how plant-soil water feedbacks responded to drought in two contrasting ecosystem types—grassland and shrubland—in the coastal foothills of southern California. During years 5–8 of an ongoing precipitation manipulation experiment, we measured changes in plant communities and soil moisture up to 2 m depth. We observed different water use patterns in grassland and shrubland communities with distinct plant functional types and water use strategies. Drought treatment did not affect perennial, deep-rooted shrubs because they could access deep soil water pools. However, mid-rooted shrubs were sensitive to drought and experienced decreased productivity and die-off. As a result, water content actually increased with drought at soil depths from 50–150 cm. In grassland, biomass production by annual species, including annual grasses and forbs, declined with drought, resulting in lower water uptake from the surface soil layer. An opportunistic “live fast, die young“ life strategy allowed these species to recover quickly once water availability increased. Our results show how drought interacts with plant community composition to affect the soil water balance of semiarid ecosystems, information that could be integrated into global scale models.

Brazil, Mexico, Argentina and Chile are four large developing countries in Latin American that are going on their development stage comparable to China. Getting insight into the carbon emissions and the effectiveness of the carbon neutrality policies in these countries are expected to be beneficial for China s carbon neutrality aspirations. With the data of the national "fossil fuel carbon emissions and terrestrial carbon balance of the four countries from 1990 to 2016, this paper examined the individuality and commonality in the carbon emission and carbon sequestration features and the driving forces. Thereafter, based on a systematic and comprehensive review of policy planning related to long-term emission reduction goals in the four Latin American countries, the scenario analysis method was used to evaluate the carbon emission reduction effectiveness and carbon neutrality of each country from 2017 to 2050. It is found as follows. ➀ The economic growth and demographic expansion were the two most important factors that pushed the fossil fuel carbon emissions in all the four countries. The improvement in energy utilization intensity in Mexico, Argentina and Chile had the effect of mitigating carbon emissions. Deforestation deviated Brazil and Argentina from their carbon neutrality goals while Mexico and Chile s terrestrial ecosystems had sequestered amount of carbon from the atmosphere to offset their fossil fuel emissions, by which Chile is nearing its carbon neutrality. ➁ The scenario analysis suggested that the current policies might facilitate Brazil to commit its 2025 and 2030 goals and close to its 2050 carbon neutrality goal. The current policies may also support Argentina commit its 2030 goal and Chile commit its 2050 carbon neutrality goal. However, there are challenges to Argentina's 2050 goal and Mexico's all intermediate goals. In light of these results, China's carbon neutrality strategies should prioritize three aspects: optimizing the energy structure, promoting energy efficiency, and enhancing terrestrial carbon sink sequestration. [ABSTRACT FROM AUTHOR]

East Asia (China, Japan, Koreas, and Mongolia) has been the world's economic engine over at least the past two decades, exhibiting a rapid increase in fossil fuel emissions of greenhouse gases (GHGs) and has expressed the recent ambition to achieve climate neutrality by mid‐century. However, the GHG balance of its terrestrial ecosystems remains poorly constrained. Here, we present a synthesis of the three most important long‐lived greenhouse gases (CO2, CH4, and N2O) budgets over East Asia during the decades of 2000s and 2010s, following a dual constraint approach. We estimate that terrestrial ecosystems in East Asia is close to neutrality of GHGs, with a magnitude of between −46.3 ± 505.9 Tg CO2eq yr−1 (the top‐down approach) and −36.1 ± 207.1 Tg CO2eq yr−1 (the bottom‐up approach) during 2000–2019. This net GHG sink includes a large land CO2 sink (−1229.3 ± 430.9 Tg CO2 yr−1 based on the top‐down approach and −1353.8 ± 158.5 Tg CO2 yr−1 based on the bottom‐up approach) being offset by biogenic CH4 and N2O emissions, predominantly coming from the agricultural sectors. Emerging data sources and modeling capacities have helped achieve agreement between the top‐down and bottom‐up approaches, but sizable uncertainties remain in several flux terms. For example, the reported CO2 flux from land use and land cover change varies from a net source of more than 300 Tg CO2 yr−1 to a net sink of ∼−700 Tg CO2 yr−1. Although terrestrial ecosystems over East Asia is close to GHG neutral currently, curbing agricultural GHG emissions and additional afforestation and forest managements have the potential to transform the terrestrial ecosystems into a net GHG sink, which would help in realizing East Asian countries' ambitions to achieve climate neutrality. Plain Language Summary: East Asia (China, Japan, Koreas and Mongolia) is not only the hotspot of anthropogenic greenhouse gas (GHG, including CO2, CH4 and N2O) emissions, but also a region with large CO2 sink. However, the greenhouse gas balance of greenhouse gases over the region is poorly understood. In this study, we performed a synthesis for over 40 flux terms to provide the first‐of‐its‐kind GHG budget assessment over the decades of 2000s and 2010s. We find terrestrial ecosystems in East Asia is close to neutrality of GHGs. The bottom‐up approach summing up component fluxes estimated a net balance of −36.1 ± 207.1 Tg CO2eq yr−1, while the top‐down approach based on atmospheric inversions estimated a net balance of −46.3 ± 505.9 Tg CO2eq yr−1. This results from compensation of the large CO2 sink by CH4 and N2O emissions, and from compensation of net GHG sink over natural ecosystems by net GHG source over agricultural ecosystems. Thus, curbing agricultural GHG emissions has the potential to realizing the ambitious goal of achieving climate neutrality over East Asia. Key Points: A comprehensive greenhouse gas (CO2, CH4 and N2O) accounting including about 40 flux terms over East Asia is reportedTerrestrial ecosystems in East Asia are close to greenhouse gas neutralNatural ecosystems is a net greenhouse gas sink, compensated by a net source from agricultural ecosystems [ABSTRACT FROM AUTHOR]

Despite numerous studies assessing the effects of microplastics (MPs) on soils and plants and their potential implications for human consumption and agriculture, there remains a lack of exploration on the role of vegetated ecosystems as natural filters of MPs pollution. The MPs stemming from anthropogenic continental activities may undergo retention within these ecosystems, preventing their dispersion into aquatic environments. However, questions are raised about their potential impact on plant health and soil quality. This review aims to address these gaps by examining studies analyzing the role of vegetated ecosystems in MPs retention, the sources and effects of these contaminants on soils, and their absorption/translocation into plants analyzing their direct effects on plant physiology and growth. Finally, future perspectives and knowledge gaps in these crucial research areas were explored.The main findings demonstrate that plants effectively play a crucial role in retaining MPs, with studies mainly focused on vegetated wetlands with halophytes, and that MPs could affect various soil properties, including bulk density, water retention, and microbiota, inducing oxidative stress on plants and disturbing their growth. However, research gaps persist, such as quantifying MPs in natural settings and investigating the complex relationship between MPs, plants, and ecosystems. Experiments often employed high concentrations of MPs, potentially deviating from natural environmental levels and thus requiring assessment of whether observed concentrations can elicit comparable effects. Additionally, the predominant focus on primary MPs in experiments overlooked other types derived from degradation of larger plastic items, warranting attention and inclusion in research efforts.In conclusion, vegetated ecosystems can naturally filter MPs from land-based activities before they reach aquatic environments. Nevertheless, these particles exhibit significant impacts on soil properties and plant growth, posing an emerging threat to terrestrial ecosystems that requires further study.

Abstract Land use change (LUC) alters the global carbon (C) stock, but our estimation of the alteration remains uncertain and is a major impediment to predicting the global C cycle. The uncertainty is partly due to the limited number and geographical bias of observations, and limited exploration of its predictors. Here we generated a comprehensive global database of 5,980 observations from 790 articles. The number of sites evaluated is at least seven times larger than in previous meta‐analyses. Our constrained estimates of different LUC's effects on soil organic C (SOC) and their variations across global climates reveal underestimation/overestimation in previous estimates. Converting forests and grasslands to croplands reduced SOC by 24.5% ± 1.53% (−11.03 ± 1.06 Mg ha−1) and 22.7% ± 1.22% (−8.09 ± 0.67 Mg ha−1), while 28.0% ± 1.56% (4.46 ± 0.42 Mg ha−1) and 33.5% ± 1.68% (5.8 ± 0.38 Mg ha−1) increases, respectively, were obtained in the reverse processes. Converting forests to grasslands decreased SOC by 2.1% ± 1.22% (−1.13 ± 0.44 Mg ha−1), while the reverse process increased SOC by 18.6% ± 1.73% (3.31 ± 0.51 Mg ha−1). Modeled relative importance of 10 drivers of LUC's impact on SOC revealed that higher initial SOC (iSOC) does not solely determine SOC loss in SOC‐negative LUC scenarios as previously proposed. Across four decades, reconverting croplands to forests and grasslands recovered only 49.5% (6.1 ± 0.51 Mg ha−1) and 75.3% (7.0 ± 0.38 Mg ha−1) of the iSOC, respectively, indicating the need for protecting C‐rich ecosystems. Our global data set advances information on LUC's effect on SOC and can be valuable to constrain Earth system models to reliably estimate global SOC stocks and plan climate change mitigation strategies.

Our research assesses the effects of four forest species, namely, Swietenia macrophylla King, Swietenia mahagoni (L.) Jack., Pinus occidentalis Swartz, and Pinus caribaea Morelet var. Caribaea, on the soil and litter organic carbon (C) stocks, C dioxide equivalent balance (BCO2 Eq.) diurnal, and periodic dynamics beneath these species. Reforestation projects in the study region cover 1200, 543, 770, and 1152 hectares, respectively, with these four species being the most relevant in reforestation projects within the country. To determine the BCO2 Eq. per unit area, we compared the greenhouse gas (GHG) fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) expressed as CO2 Eq. units with the organic C stocks found in the mineral soil to a depth of 30 cm and in the forest litter. In four measurement periods over 18 months, we conducted field measurements in sixteen stands, four per species. Our results indicate that S. mahagoni emitted the lowest CO2 Eq., while S. macrophylla released the highest amount into the atmosphere. At the end of the 18 months, BCO2 Eq. from S. macrophylla soils was 299.70 metric tons ha−1 year−1, while for P. occidentalis, P. caribaea, and S. mahagoni, the corresponding quantities were 103.64, 146.41, and 72.34, respectively. All species showed a general upward pattern in soil respiration from September 2020 to March 2022. The average CO2 Eq. flux rates to the atmosphere were approximately 65.4, 51.1, and 75.9 percent higher in S. macrophylla soils compared to the respective rates of P. occidentalis, P. caribaea, and S. mahagoni.

Pollution by anthropogenic litter is a major threat to global ecosystems. Seabirds are frequently used as environmental monitors of litter ingestion, but similar research is rare for terrestrial birds. Here, we focused on pellet analysis from 117 nests of an iconic bird of the Western Palearctic, the white stork (Ciconia ciconia), breeding in southern and southwestern Poland in a farmland landscape, far away from large dumps and landfills. We found that most prey items in the diet of white storks were invertebrates (particularly from orders Coleoptera, Orthoptera, and Hymenoptera) but vertebrate prey comprised most of the biomass. Further analysis revealed that anthropogenic litter was found in 22.7% of pellets (34.2% of breeding pairs) with plastic (8.4%) and cigarette filters (6.9%) being most prevalent. This study represents the first assessment through pellet analysis of the ingestion of anthropogenic litter by live wild storks in Poland and also by a migratory population of white storks. Our study indicates a potentially significant transfer of plastic and other anthropogenic material through terrestrial food webs. [ABSTRACT FROM AUTHOR]

Through their rooting profiles and water demands, plants affect the distribution of water in the soil profile. Simultaneously, soil water content controls plant development and interactions within and between plant communities. These plant-soil water feedbacks might vary across plant communities with different rooting depths and species composition. In semiarid environments, understanding these differences will be essential to predict how ecosystems will respond to drought, which may become more frequent and severe with climate change. In this study, we tested how plant-soil water feedbacks responded to drought in two contrasting ecosystem types—grassland and shrubland—in the coastal foothills of southern California. During years 5–8 of an ongoing precipitation manipulation experiment, we measured changes in plant communities and soil moisture up to 2 m depth. We observed different water use patterns in grassland and shrubland communities with distinct plant functional types and water use strategies. Drought treatment did not affect perennial, deep-rooted shrubs because they could access deep soil water pools. However, mid-rooted shrubs were sensitive to drought and experienced decreased productivity and die-off. As a result, water content actually increased with drought at soil depths from 50–150 cm. In grassland, biomass production by annual species, including annual grasses and forbs, declined with drought, resulting in lower water uptake from the surface soil layer. An opportunistic "live fast, die young" life strategy allowed these species to recover quickly once water availability increased. Our results show how drought interacts with plant community composition to affect the soil water balance of semiarid ecosystems, information that could be integrated into global scale models. [ABSTRACT FROM AUTHOR]

Summary: Potassium (K+) is the most abundant inorganic cation in plant cells, playing a critical role in various plant functions. However, the impacts of K on natural terrestrial ecosystems have been less studied compared with nitrogen (N) and phosphorus (P).Here, we present a global meta‐analysis aimed at quantifying the response of aboveground production to K addition. This analysis is based on 144 field K fertilization experiments. We also investigate the influences of climate, soil properties, ecosystem types, and fertilizer regimes on the responses of aboveground production.We find that: K addition significantly increases aboveground production by 12.3% (95% CI: 7.4–17.5%), suggesting a widespread occurrence of K limitation across terrestrial ecosystems; K limitation is more prominent in regions with humid climates, acidic soils, or weathered soils; the effect size of K addition varies among climate zones/regions, and is influenced by multiple factors; and previous N : K and K : P thresholds utilized to detect K limitation in wetlands cannot be applied to other biomes.Our findings emphasize the role of K in limiting terrestrial productivity, which should be integrated into future terrestrial ecosystems models. [ABSTRACT FROM AUTHOR]

Purpose: The control of the exogenous carbon-induced soil-priming effect (PE) by soil microbes, carbon, nitrogen, and carbon/nitrogen is still uncertain. To examine the relationship between diverse soil properties and the PE, the research was conducted using soils from forest, cropland, and grassland ecosystems. Methods: We introduced a solution of 13C-labeled glucose (containing 6 atom% 13C) into soils collected from three distinct ecosystems. For the control group, we added an equal amount of water to the soils. Subsequently, all treatment and control samples were incubated at 60% of their water holding capacity and maintained at a temperature of 25 °C for a period of 28 days. Results: The magnitude of priming on native SOC was significantly higher in grassland ecosystems than in forest and cropland ecosystems. The results of structural equation modelling revealed a significant positive association of the PE with the soil carbon/nitrogen ratio, bacterial diversity, and community composition, as well as a negative association of the PE with SOC, dissolved organic carbon, and total nitrogen. Network analysis showed that the keystone taxa for each ecosystem were different. Sphingomonas, SBR1031, BD2-11-terrestrial-group, and Sebacina were the keystone taxa significantly positively associated with the PE, whereas Solirubrobacter, Bacillus, and Preussia were the keystone taxa significantly negatively associated with the PE. Conclusion: Our findings are significant for studying carbon fluxes, improving soil carbon dynamics models, and understanding soil microbe, carbon, and nitrogen relationships with SOC mineralization. This understanding is crucial for mitigating climate change, promoting sustainable land management, and enhancing soil carbon stabilization. [ABSTRACT FROM AUTHOR]

The carbon balance of the global ecosystems is significantly influenced by the soil organic carbon (SOC) pool in China's terrestrial ecosystems. Nevertheless, the current understanding of the main controlling factors of SOC in different ecosystems and their discrepancies is limited. The goal of this research was to better understand the human and environmental variables affecting SOC in China's terrestrial ecosystems. We designed a conceptual framework using 2674 samples collected from four ecosystems (grasslands, shrublands, wetlands, and croplands) in China during the 2000–2014 period, combining geodetector and multiple regression (MR) approaches to investigate the effects of environmental conditions, human activity, and their interplay on surface SOC (0–20 cm). Results showed that there were large discrepancies in the strength of influencing factors among different ecosystems. Total nitrogen (TN), mean annual temperature (MAT), and bulk density (BD) were the major factors influencing SOC in grasslands. BD, TN, and pH dominated in shrublands. For wetlands, SOC stocks were primarily attributed to maximum temperature (TMMX), MAT, and potential evapotranspiration (PET). Croplands are predominantly controlled by minimum temperature (TMMN), MAT, and TN. These results highlight that natural factors, particularly climatic and soil characteristics, were the dominant factors controlling SOC stocks in China's terrestrial ecosystems. This work also highlights that the interaction of two influencing factors, especially, pairs of soil characteristics factors, pairs of climate and soil characteristics factors, can well explain the drivers of SOC on the surface soil in China. Our study emphasizes the spatial heterogeneity of the factors that influence SOC in terrestrial ecosystems, enhancing knowledge of SOC at the national level, and providing the guideline for devising better policy to improve C sequestration and mitigate climate changes. [ABSTRACT FROM AUTHOR]

We provide here a model-based estimate of the transit time of carbon through the terrestrial biosphere, since the time of carbon uptake through photosynthesis until its release through respiration. We explored the consequences of increasing productivity versus increasing respiration rates on the transit time distribution and found that while higher respiration rates induced by higher temperature increase the transit time because older carbon is respired, increases in productivity cause a decline in transit times because more young carbon is available to supply increased metabolism. The combined effect of increases in temperature and productivity results in a decrease in transit times, with the productivity effect dominating over the respiration effect. By using an ensemble of simulation trajectories from the Carbon Data Model Framework (CARDAMOM), we obtained time-dependent transit time distributions incorporating the twentieth century global change. In these simulations, transit time declined over the twentieth century, suggesting an increased productivity effect that augmented the amount of respired young carbon, but also increasing the release of old carbon from high latitudes. The transit time distribution of carbon becomes more asymmetric over time, with more carbon transiting faster through tropical and temperate regions, and older carbon being respired from high latitude regions. This article is part of the Theo Murphy meeting issue 'Radiocarbon in the Anthropocene'. [ABSTRACT FROM AUTHOR]

Terrestrial ecosystems are under the enormous pressure of land use management regimes through human disturbances, resulting in the disruption of biogeochemical cycles and associated ecosystem services. Nitrogen (N) in soil ecosystems is of vital importance for primary productivity, hence estimating the extent of these human interventions on N-cycling processes becomes imperative from economic and environmental perspectives. This work investigated the impacts of variable anthropogenic activities on N cycling in three different terrestrial ecosystems (arable, grassland, and forest) in three regions of lower Himalaya, Pakistan. Potential nitrification (PNA) and denitrification (DEA) enzyme activities, relative distribution of inorganic N species (NH4, NO3), and the role of inherent edaphic factors were assessed. Results revealed high nitrification potentials and increased nitrous oxide (N2O) emissions in the incubated soil microcosms, in the order as arable > grassland > forest ecosystems. Notably, higher rates of both studied processes (~ 30–50%) and elevated soil mineral nitrogen pool were observed in arable ecosystems. Forest soils, assumed as pristine ecosystems relying mainly on natural N fixation, produced (de)nitrification rates relatively lower than grasslands, followed by arable soils which were moderately disturbed through long-term fertilization and intensive land-use regimes. Linear regression modeling revealed that the inorganic N species (particularly NO3), and inherent edaphic factors were the key determinants of high (de)nitrification rates, hence warn of accelerated N losses in these ecosystems. The study highlights that elevated PNA and DEA being proxies for the altered N cycling in the studied terrestrial ecosystems are of great ecological relevance in view of predicted N2O budget in the lower Himalaya. [ABSTRACT FROM AUTHOR]

Terrestrial ecosystems play a central role in the global carbon cycle and climate mitigation due to their offering of a large carbon sink. More than one‐fifth of the geographical area of India, one of the largest nations on the Earth, is forested, which is highly diverse in vegetation and climate types, offers huge potential for carbon sequestration, but remains vulnerable to climate change. Hence, it is imperative to know the future changes in the terrestrial carbon budget over this region. Gross primary productivity (GPP) represents the carbon uptake by terrestrial ecosystems. The multimodel ensembles of GPP simulated by the sixth phase of the Coupled Model Intercomparison Project (CMIP6) provide a useful means in this regard. In this work, we study the strength and variability of GPP over India in the near‐past and future using these simulations. In future, all the models show an increasing trend in GPP, however, with widely varying trends. The preferred month of carbon uptake differs among the models. A comparison with a satellite biophysical record shows the models underestimated the GPP during the near‐past over India. The carbon uptake in the Eastern Himalaya dominates the Western Himalaya and central Indian regions. Specifically, till 2100, the growth rate of GPP varies from 4.9 to 16.69 gC m−2 y−2, from 2.47 to 18.91 gC m−2 y−2, and from 0.32 to 21.95 gC m−2 y−2 over these three regions, respectively. Plain Language Summary: Climate change is an imminent problem driven by greenhouse gases, with adverse impacts on the Earth system. Carbon dioxide is a major greenhouse gas. Plants offer a natural strategy to mitigate climate change by their photosynthetic carbon uptake. For climate change impact assessment, projections of climate models are widely used, developed from our understanding of the Earth system, as measured by the observations. India is a large and populous country that remains highly vulnerable to climate change; it also plays a key role in global climate change and its mitigation. However, to devise a suitable mitigation strategy the future carbon sequestration by the natural ecosystems in this region needs to be quantified. The World Climate Research Program developed the Coupled Model Intercomparison Project, a multi‐model ensemble study providing future projections of climate variables under different climate change scenarios. In this work, we use these ensembles to study the future photosynthetic carbon uptake over India and its three key forested regions. We find the photosynthetic carbon uptake to increase manifold over India, with significant inter‐model uncertainties. We also find the Eastern Himalaya to have stronger biospheric carbon removal from the atmosphere than the Western Himalaya and Central Indian regions. Key Points: Photosynthetic carbon uptake increases over India in future with the annual growth rate varying from 3 to 15 gC m−2 y−2The photosynthetic carbon uptake is larger in Eastern Himalaya compared to Western Himalaya and Central IndiaThere is a large discord on the strength, trend and variability of Gross primary productivity over India among CMIP6 models and Moderate Resolution Imaging Spectroradiometer [ABSTRACT FROM AUTHOR]

Silicon fertilisers are widely utilised to achieve higher productivity in global terrestrial ecosystems, but their impact on the carbon cycle remains unclear. In this study, we used a meta-analysis approach to quantify the response of carbon pools and fluxes in terrestrial ecosystems worldwide to the application of silicon fertiliser while also investigating the factors influencing this response. The findings indicated that silicon fertiliser application led to significant increases in various carbon components: plant aboveground carbon increased by 22.9%, plant belowground carbon increased by 17.3%, litter carbon increased by 8.3%, and the SOC content increased by 8.6%. Furthermore, the net photosynthetic rate of plants was significantly enhanced by 28.1% through the application of silicon fertiliser, along with a notable increase of 36.9% in the net primary productivity of ecosystems, which exhibited a strong correlation with alterations in ecosystem carbon pools. A considerable reduction of 29.6% in soil CH4 emissions was observed, whereas the influence of silicon fertiliser on the litter decomposition rate and net soil CO2 emissions was not statistically significant. Moreover, fertilisation (such as vegetation and soil types), climatic conditions, and silicon fertiliser application techniques have been found to affect the responses of carbon pools and fluxes to silicon fertiliser application. Finally, a potential mechanism by which silicon fertilisation can affect plant growth, litterfall, soil organic carbon stability, and soil carbon emissions directly and indirectly by changing the available silicon and soil pH is proposed to explain the positive effects of silicon fertiliser application on terrestrial ecosystem carbon pools. This effect may change owing to the influence of fertilisation technology, fertilisation, climate, and other factors.

Abstract Objectives Soil fauna plays a crucial role in contributing to litter breakdown, accelerating the decomposition rate and enhancing the biogeochemical cycle in terrestrial ecosystems. Comprehending the specific fauna role of functional species in litter decomposition is challenging due to their vast numbers and diversity. Climate and litter quality are widely acknowledged as dominant drives of litter decomposition across large spatial scales. However, the pattern of climate and litter quality modulates the effect of soil fauna on litter decomposition remains largely unexplored. To address this gap, we conducted an extensive analysis using data from 81 studies to investigate how climate and litter traits affects soil fauna in the decomposition. Data description The paper describes fauna body size, climate zones (tropical, subtropical and temperate), ecosystem types (forest, grassland, wetland and farmland), soil types (sand, loam and clay), decomposed duration ( 360 days), litter initial traits, average annual temperature and precipitation. The litter traits encompass various parameters such as concentrations of carbon, nitrogen, phosphorus, potassium, lignin, cellulose, total phenol, condensed tannin, hydrolysable tannin and other nutrient traits. These comprehensive datasets provide valuable insights into the role of soil fauna on the decomposition at global scale. Furthermore, the data will give researchers keys to assess how climate, litter quality and soil fauna interact to determine decomposition rates.

Ecosystem-scale water use efficiency (WUE), as a quantification of the coupling between carbon and water cycle, determines whether vegetation could survive under severe drought stress. Nevertheless, how extreme droughts affect ecosystem-scale WUE and its difference among regions and biomes are still poorly understood. In this study, using data-oriented gridded products of gross primary productivity (GPP) and evapotranspiration (ET), we assessed the ecosystem WUE change during extreme drought years over China, and further compared drought impacts on WUE between forest and grassland ecosystems. We found a spatial heterogeneity of WUE change in response to extreme droughts across regions. Particularly, grassland WUE was substantially reduced concurrent with suppressed photosynthesis, while most of forest exhibited slightly decreased or even increased WUE under extreme droughts. In addition, we demonstrated that drought characteristics and environmental conditions modulated drought impacts on WUE. Temperature anomalies during droughts and leaf area were found to be the predominant factors driving WUE change for both forest and grassland. With increasing occurrence of compound dry and hot extremes, our results, therefore, would be an insightful supplement to the current understanding of the influence of extreme events on terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

The biosphere is changing rapidly due to human endeavour. Because ecological communities underlie networks of interacting species, changes that directly affect some species can have indirect effects on others. Accurate tools to predict these direct and indirect effects are therefore required to guide conservation strategies. However, most extinction‐risk studies only consider the direct effects of global change—such as predicting which species will breach their thermal limits under different warming scenarios—with predictions of trophic cascades and co‐extinction risks remaining mostly speculative. To predict the potential indirect effects of primary extinctions, data describing community interactions and network modelling can estimate how extinctions cascade through communities. While theoretical studies have demonstrated the usefulness of models in predicting how communities react to threats like climate change, few have applied such methods to real‐world communities. This gap partly reflects challenges in constructing trophic network models of real‐world food webs, highlighting the need to develop approaches for quantifying co‐extinction risk more accurately. We propose a framework for constructing ecological network models representing real‐world food webs in terrestrial ecosystems and subjecting these models to co‐extinction scenarios triggered by probable future environmental perturbations. Adopting our framework will improve estimates of how environmental perturbations affect whole ecological communities. Identifying species at risk of co‐extinction (or those that might trigger co‐extinctions) will also guide conservation interventions aiming to reduce the probability of co‐extinction cascades and additional species losses. [ABSTRACT FROM AUTHOR]

Soil pH is critically important in regulating soil nutrients and thus influencing the biodiversity and ecosystem functions of terrestrial ecosystems. Despite the ongoing threat of nitrogen (N) pollution especially in the fast-developing regions, it remains unclear how increasing N deposition affects soil pH across global terrestrial ecosystems. By conducting a global meta-analysis with paired observations of soil pH under N addition and control from 634 studies spanning major types of terrestrial ecosystems, we show that soil acidification increases rapidly with N addition amount and is most severe in neutral-pH soils. Grassland soil pH decreases most strongly under high N addition while wetlands are the least acidified. By extrapolating these relationships to global mapping, we reveal that atmospheric N deposition leads to a global average soil pH decline of -0.16 in the past 40 years and regions encompassing Eastern United States, Southern Brazil, Europe, and South and East Asia are the hotspots of soil acidification under N deposition. Our results highlight that anthropogenically amplified atmospheric N deposition has profoundly altered global soil pH and chemistry. They suggest that atmospheric N deposition is a major threat to global terrestrial biodiversity and ecosystem functions. [ABSTRACT FROM AUTHOR]

The fraction of absorbed photosynthetically active radiation (FPAR) is a key biophysiological parameter of terrestrial ecosystems. However, due to a lack of data with adequate spatial resolution and in long enough time series, there have been limitations in exploring the spatiotemporal changes of vegetation and response to climate change. In this study, a 1 km spatial resolution and 8-day period length dataset (FPARANN) was developed covering the years 1980 to 2018 and evaluated on spatiotemporal change consistency by validating with Gross Primary Production (GPP) observations from the Chinese Flux Observation and Research Network (ChinaFLUX), and comparison with other FPAR products. FPARANN provided a comparable performance in capturing seasonal change observed through GPP, according to the coefficient of determination (R2): 0.50, 0.51, 0.70 and 0.74 averaged for all sites, forest sites, grassland sites and cropland flux sites, respectively. The new data had more spatial similarity to the MODIS FPAR product (FPARMCD15A2) with a greater R2 (0.77) and a lower RMSE (0.12) than other products. With a newly developed dataset, combined with FPARANN (1980–2003) and FPARMCD15A2 (2004–2018), an overall increasing trend in FPAR was found for over 81% of the vegetated area of China from 1980 to 2018. FPAR increased more rapidly for over 83.7% of the area in the 2010s, and at a slower pace for over 62.1% of the area in the early 2000s, which was attributed to a decadal shifting of climate change. This study implies the new dataset is useful in quantifying vegetation changes and would be an important data source for future study of the carbon cycle, soil erosion, or evapotranspiration, with great application potential. [ABSTRACT FROM AUTHOR]

There is an unprecedented array of new satellite technologies with capabilities for advancing our understanding of ecological processes and the changing composition of the Earth's biosphere at scales from local plots to the whole planet. We identified 48 instruments and 13 platforms with multiple instruments that are of broad interest to the environmental sciences that either collected data in the 2000s, were recently launched, or are planned for launch in this decade. We have restricted our review to instruments that primarily observe terrestrial landscapes or coastal margins and are available under free and open data policies. We focused on imagers that passively measure wavelengths in the reflected solar and emitted thermal spectrum. The suite of instruments we describe measure land surface characteristics, including land cover, but provide a more detailed monitoring of ecosystems, plant communities, and even some species then possible from historic sensors. The newer instruments have potential to greatly improve our understanding of ecosystem functional relationships among plant traits like leaf mass area (LMA), total nitrogen content, and leaf area index (LAI). They provide new information on physiological processes related to photosynthesis, transpiration and respiration, and stress detection, including capabilities to measure key plant and soil biophysical properties. These include canopy and soil temperature and emissivity, chlorophyll fluorescence, and biogeochemical contents like photosynthetic pigments (e.g., chlorophylls, carotenoids, and phycobiliproteins from cyanobacteria), water, cellulose, lignin, and nitrogen in foliar proteins. These data will enable us to quantify and characterize various soil properties such as iron content, several types of soil clays, organic matter, and other components. Most of these satellites are in low Earth orbit (LEO), but we include a few in geostationary orbit (GEO) because of their potential to measure plant physiological traits over diurnal periods, improving estimates of water and carbon budgets. We also include a few spaceborne active LiDAR and radar imagers designed for quantifying surface topography, changes in surface structure, and 3-dimensional canopy properties such as height, area, vertical profiles, and gap structure. We provide a description of each instrument and tables to summarize their characteristics. Lastly, we suggest instrument synergies that are likely to yield improved results when data are combined.

Objectives: Soil fauna plays a crucial role in contributing to litter breakdown, accelerating the decomposition rate and enhancing the biogeochemical cycle in terrestrial ecosystems. Comprehending the specific fauna role of functional species in litter decomposition is challenging due to their vast numbers and diversity. Climate and litter quality are widely acknowledged as dominant drives of litter decomposition across large spatial scales. However, the pattern of climate and litter quality modulates the effect of soil fauna on litter decomposition remains largely unexplored. To address this gap, we conducted an extensive analysis using data from 81 studies to investigate how climate and litter traits affects soil fauna in the decomposition. Data description: The paper describes fauna body size, climate zones (tropical, subtropical and temperate), ecosystem types (forest, grassland, wetland and farmland), soil types (sand, loam and clay), decomposed duration (< 180, 180–360, > 360 days), litter initial traits, average annual temperature and precipitation. The litter traits encompass various parameters such as concentrations of carbon, nitrogen, phosphorus, potassium, lignin, cellulose, total phenol, condensed tannin, hydrolysable tannin and other nutrient traits. These comprehensive datasets provide valuable insights into the role of soil fauna on the decomposition at global scale. Furthermore, the data will give researchers keys to assess how climate, litter quality and soil fauna interact to determine decomposition rates. [ABSTRACT FROM AUTHOR]

For a comprehensive response to climate change and low carbon development mode, the 3S-based regional terrestrial carbon cycle model in Luanhe basin is constructed in accordance with componentbased development strategy to identify carbon cycle evolution of terrestrial ecosystem under the background of local changes, combining measured weather data, prototype observation data of soil and plants as well as remote-sensing information in different spatial and temporal scales. The model has the ability of describing canopy fluxes, net primary productivity, biomass allocation and turnover, mortality, decomposition of soil organic matter and other dynamic processes. The carbon cycle evolution in Luanhe Basin from 1995 to 2010 is simulated and analyzed. The results are shown as follows: 1) in the temporal scale, inter-annual change of leaf area index with a slight growth trend is larger than that of net primary productivity (NPP), ground and underground biomass and soil carbon content; 2) There are obvious regional differences in spatial view, spatial distribution of results are consistent with those of watershed plant and soil, displaying the characteristics that the above major variables of mountainous regions in middle-upper reaches are greater than those of grassland meadows in the upstream and plains in the downstream. [ABSTRACT FROM AUTHOR]

Existing quantitative syntheses on how biodiversity responds to anthropogenic habitat change appear to sometimes mix different biodiversity metrics in drawing inferences. This "mixing metrics" practice, if prevalent, would considerably bias our understanding of biodiversity responses and render uninterpretable conclusions. However, the prevalence of this practice remains unknown, and the bias it potentially renders has not been empirically assessed. We fill this gap by conducting a systematic literature assessment of existing syntheses on biodiversity responses to habitat change, along with an analysis of a global database specifically on forest restoration. We found that the "mixing metrics" practice was used in almost a quarter of existing syntheses across a wide range of ecosystem and habitat change types. This practice predictably altered the quantitative, and frequently even the qualitative, inferences on biodiversity responses to forest restoration, in ways contingent on the composition of metrics mixed. We call on future syntheses to be cognizant of the difference in metric meaning and behaviors, and to avoid mixing different metrics in studying biodiversity responses to habitat change. [ABSTRACT FROM AUTHOR]

The carbon dioxide (CO2) fertilization effect has captured worldwide attention, owing to its tremendous potential to challenge existing predictions of future climate. However, quantifying the CO2 fertilization effect (CFE) has proven to be challenging, given that it is closely entangled with other ecological and environmental processes. Recent years have witnessed significant advances with breakthroughs using theoretical methods to infer the CFE from eddy covariance tower measurements. Building on earlier findings, this study presents an innovative approach that utilizes explainable machine-learning techniques—describing the partial dependence of the response variable to each explanatory variable—to quantify the global CFE from remote-sensing platforms with an averaged $R ^{2}$ of 0.85. This study provides the first data-driven evidence of the global CFE and confirms the potential for extrapolation to the globe. The findings suggest that: 1) the employment of satellite vegetation proxies contributed to more than 50% of the fitting of gross primary productivity (GPP) and 2) the manifestation of the CO2 fertilization impact demonstrated heterogeneity among various types of ecosystems, and in some cases, an adverse effect was detected in broadleaf forests. Our results have significant implications for the preservation and protection of terrestrial ecosystems, particularly for a carbon-neutral future. This study, therefore, provides a valuable contribution to the growing body of knowledge in this area and highlights the potential of innovative analytical techniques to address complex ecological challenges. [ABSTRACT FROM AUTHOR]

The production and disposal of plastics have become significant concerns for the sustainability of the planet. During the past 75 years, around 80% of plastic waste has either ended up in landfills or been released into the environment. Plastic debris released into the environment breaks down into smaller particles through fragmentation, weathering, and other disintegration processes, generating microplastics (plastic particles ≤ 5 mm in size). Although marine and aquatic ecosystems have been the primary focus of microplastic pollution research, a growing body of evidence suggests that terrestrial ecosystems are equally at risk. Microplastic contamination has been reported in various terrestrial environments from several sources such as plastics mulch, pharmaceuticals and cosmetics, tire abrasions (tire wear particles), textiles industries (microfibers), sewage sludge, and plastic dumping. Recent studies suggest that the soil has become a significant sink for pollutants released into terrestrial ecosystems and is often contaminated with a mixture of organic and inorganic pollutants. This has gradually caused adverse impacts on soil health and fertility by affecting soil pH, porosity, water-holding capacity, and soil microbial enzymatic activities. Microplastics can interact with the co-existing pollutants of the environments by adsorbing the contaminants onto their surfaces through various intermolecular forces, including electrostatic, hydrophobic, non-covalent, partition effects, van der Waals forces, and microporous filling mechanisms. This subsequently delays the degradation process of existing contaminants, thereby affecting the soil and various ecological activities of the ecosystem. Thus, the present article aims to elucidate the deleterious impact of microplastics and their interactions with other pollutants in the terrestrial ecosystem. This review also addresses the impact of microplastics in disrupting the soil sustainability of the planet. [ABSTRACT FROM AUTHOR]

Carrion production is one of the most crucial yet neglected and understudied processes in food webs and ecosystems. In this study, we performed a large-scale estimation of the maximum potential production and spatial distribution of ungulate carrion biomass from five major sources in peninsular Spain, both anthropogenic (livestock, big game hunting, roadkills) and natural (predation, natural mortality). Using standardized ungulate carrion biomass (kg/year/100km2) estimates, we evaluated the relationship between ungulate carrion production and two ecosystem-level factors: global human modification (GHM) and primary productivity (NDVI). We found that anthropogenic carrion sources supplied about 60 times more ungulate carrion biomass than natural sources (mean = 90,172 vs. 1533 kg/year/100km2, respectively). Within anthropogenic carrion sources, livestock was by far the major carrion provider (91.1% of the annual production), followed by big game hunting (7.86%) and roadkills (0.05%). Within natural carrion sources, predation of ungulates provided more carrion (0.81%) than natural mortality (0.13%). Likewise, we found that the spatial distribution of carrion differed among carrion sources, with anthropogenic carrion being more aggregated in space than natural carrion. Our models showed that GHM was positively related to carrion production from livestock and roadkills, and that wild ungulate carrion supplied by natural sources and big game hunting was more frequently generated in more productive areas (higher NDVI). These findings indicate a disconnection between the main ungulate carrion source (livestock) and primary productivity. Ongoing socio-economic changes in developed countries (for example increase of intensive livestock husbandry and rewilding processes) could lead to additional alteration of carrion production processes, with potential negative impacts at the community and ecosystem levels. Overall, we highlight that carrion biomass quantification should be considered a crucial tool in evaluating ecosystem health and delineating efficient ecosystem management guidelines in the Anthropocene. [ABSTRACT FROM AUTHOR]

Forests sequester ∼25% of anthropogenic carbon (C) emissions annually and are of increasing interest for their potential as Nature‐based Climate Solutions (NbCS). Emergent from the need to assess terrestrial ecosystem health and quantify C storage and fluxes, several gridded products documenting terrestrial C and changes in C stocks over time have been developed. However, researchers have not yet systematically compared C distributions across products, or developed a clear path forward for investigating and leveraging this cross‐product uncertainty in estimates of terrestrial C. Alaniz et al. (2022, https://doi.org/10.1029/2021EF002560) synthesize multiple published products to constrain the distribution of forest C stocks and fluxes globally. Building off of their results, we comment on opportunities for advancing both basic science and NbCS policy recommendations through systematic product cross‐comparisons and targeting of areas with differing levels of uncertainties in the terrestrial C sink. Plain Language Summary: Forests absorb and store a large amount of the carbon from the CO2 emitted by humans. These forests also provide the potential for storing more human emitted CO2 that helps delay climate change through targeted forest management. However, for both natural sciences and management, careful documentation of the amount of carbon in forests and how it is changing is necessary. Over time the number of ways to measure and evaluate this carbon has increased. The synthesis in Alaniz et al. (2022, https://doi.org/10.1029/2021EF002560) of these numerous efforts provides an integrated view of carbon in forests and how it is changing. We propose expanding these observational synthesis efforts, leveraging uncertainty to help direct both basic scientific research and the potential for managing ecosystems to delay climate change. Key Points: Monitoring forest carbon is important both for basic science and climate change mitigationCross‐dataset comparisons are increasingly important with increasing data availability to characterize uncertaintyUncertainty in terrestrial carbon stocks and fluxes can be used to gain better process understanding and make policy recommendations [ABSTRACT FROM AUTHOR]

Evidence for the multifaceted responses of terrestrial ecosystems has been shown by the weakening of CO2 fertilization-induced and warming-controlled productivity gains. The intricate relationship between vegetation productivity and various environmental controls still remains elusive spatially. Here several inherent preponderances make China a natural experimental setting to investigate the interaction and relative contributions of five drivers to gross primary productivity for the period from 1982 to 2018 (i.e., elevated atmospheric CO2 concentrations, climate change, nutrient availability, anthropogenic land use change, and soil moisture) by coupling multiple long-term datasets. Despite a strikingly prominent enhancement of vegetation productivity in China, it exhibits similar saturation responses to the aforementioned environmental drivers (elevated CO2, climatic factors, and soil moisture). The CO2 fertilization-dominated network explains the long-term variations in vegetation productivity in humid regions, but its effect is clearly attenuated or even absent in arid and alpine environments controlled by climate and soil moisture. Divergence in interactions also provides distinct evidence that water availability plays an essential role in limiting the potential effects of climate change and elevated CO2 concentrations on vegetation productivity. Unprecedented industrialization and dramatic surface changes may have breached critical thresholds of terrestrial ecosystems under the diverse natural environment and thus forced a shift from a period dominated by CO2 fertilization to a period with nonlinear interactions. These findings suggest that future benefits in terrestrial ecosystems are likely to be counteracted by uncertainties in the complicated network, implying an increasing reliance on human societies to combat potential risks. Our results therefore highlight the need to account for the intricate interactions globally and thus incorporate them into mitigation and adaptation policies. [ABSTRACT FROM AUTHOR]

Intensive human exploitation of the Antarctic fur seal (Arctocephalus gazella) in its primary population centre on sub-Antarctic South Georgia, as well as on other sub-Antarctic islands and parts of the South Shetland Islands, in the eighteenth and nineteenth centuries rapidly brought populations to the brink of extinction. The species has now recovered throughout its original distribution. Non-breeding and yearling seals, almost entirely males, from the South Georgia population now disperse in the summer months far more widely and in higher numbers than there is evidence for taking place in the pre-exploitation era. Large numbers now haul out in coastal terrestrial habitats in the South Orkney Islands and also along the north-east and west coast of the Antarctic Peninsula to at least Marguerite Bay. In these previously less- or non-visited areas, the seals cause levels of damage likely never to have been experienced previously to fragile terrestrial habitats through trampling and over-fertilisation, as well as eutrophication of sensitive freshwater ecosystems. This increased area of summer impact is likely to have further synergies with aspects of regional climate change, including reduction in extent and duration of sea ice permitting seals access farther south, and changes in krill abundance and distribution. The extent and conservation value of terrestrial habitats and biodiversity now threatened by fur seal distribution expansion, and the multiple anthropogenic factors acting in synergy both historically and to the present day, present a new and as yet unaddressed challenge to the agencies charged with ensuring the protection and conservation of Antarctica's unique ecosystems. [ABSTRACT FROM AUTHOR]

Abstract Existing quantitative syntheses on how biodiversity responds to anthropogenic habitat change appear to sometimes mix different biodiversity metrics in drawing inferences. This “mixing metrics” practice, if prevalent, would considerably bias our understanding of biodiversity responses and render uninterpretable conclusions. However, the prevalence of this practice remains unknown, and the bias it potentially renders has not been empirically assessed. We fill this gap by conducting a systematic literature assessment of existing syntheses on biodiversity responses to habitat change, along with an analysis of a global database specifically on forest restoration. We found that the “mixing metrics” practice was used in almost a quarter of existing syntheses across a wide range of ecosystem and habitat change types. This practice predictably altered the quantitative, and frequently even the qualitative, inferences on biodiversity responses to forest restoration, in ways contingent on the composition of metrics mixed. We call on future syntheses to be cognizant of the difference in metric meaning and behaviors, and to avoid mixing different metrics in studying biodiversity responses to habitat change.

The issue of plastic pollution is recognised as a pervasive and ubiquitous problem which can pose a threat to ecosystems worldwide and potentially affect human health. In this perspective, we selected the latest research that identifies potential impacts beyond individual species to draw attention on wider biogeochemical cycles and the most fundamental biological processes we all depend on, namely, breathing, feeding and carrying offspring. We highlight the need for uniform research methods, giving examples of protocols and indicator species that should be evaluated by the research community for their potential wide adoption. We stress the need for systemic changes and our role as scientific community to demand changes proportionate to the severity and implications of our findings. We further explore the push and pull mechanisms between researchers and policymakers in relation to the global environmental challenges such as plastic pollution. Finally, we recommend a path of action inspired by the global action taken to address the ozone layer depletion by banning chlorofluorocarbons (CFC).

IntroductionGlobal climate change, increase in human activities, and prominence of ecological issues have led to uneven quantitative and spatial distributions of carbon emission and sequestration of terrestrial ecosystems. Such uneven distributions can lead to more negative impacts on the natural environment and human living conditions.MethodsTherefore, based on the carbon neutralization policy, we conducted geographically weighted regression (GWR) modeling in this study using panel data from 352 Chinese prefectural administrative districts in 2000, 2005, 2010, and 2017 to analyze and determine the impact factors and their spatial distribution for carbon emission and sequestration of terrestrial ecosystems.ResultsOur results showed that total population (TP), per capita gross domestic product (GDP) (PCG), proportion of secondary industry output (PSIO), scale of urban built-up area (SUB), green space proportion in city areas (GSP), normalized difference vegetation index (NDVI), and temperature (TEM) are factors driving carbon sequestration and carbon emission. The spatial distribution of these driving factors in mainland China is: (1) TP showed a negative correlation to carbon emission in most areas, while it exhibited a positive correlation to carbon sequestration in the southern, southwestern, and western parts of northwest China; however, in all other areas, TP showed a negative correlation with carbon sequestration; (2) PCG was positively correlated to carbon emission in most areas of China and to carbon sequestration in southwest, south, central, and northeast China; however, PCG demonstrated a negative correlation to carbon sequestration in the remaining areas; (3) PSIO and SUB presented a positive correlation to carbon emission and a negative correlation to carbon sequestration in most areas; (3) In contrast, GSP showed a negative correlation to carbon emission and a positive correlation to carbon sequestration in most areas; (5)NDVI showed a negative correlation to carbon emission and carbon sequestration in most areas toward the east of the “Heihe-Tengchong Line”; NDVI was positively correlated to both carbon emission and sequestration toward the west of this line; (6)TEM was positively correlated to carbon emission and sequestration in most parts of China.DiscussionBased on these results, we further divided the Chinese cities into 6 groups: (1) Groups 1, 2, 3, and 6 are areas where carbon emission and sequestration are governed by both socioeconomic and natural ecological factors. The major driving factors of carbon emission and carbon sequestration in group 1 are PSIO, GSP, and NDVI; the driving factors of group 2 are SUB and NDVI. Meanwhile, carbon emission and sequestration in group 3 are governed by PCG, GSP, and NDVI; for group 6, carbon emission and sequestration are controlled by PCG, SUB, GSP, and NDVI; (2) Group 4 represents areas where carbon emission and sequestration are majorly impacted by PCG and SUB, thereby rendering socioeconomic factors as the major driving forces. Group 5 represents areas where carbon emission and sequestration are sensitive to the natural environment, with GSP and NDVI being the driving factors. Considering the uneven distribution of carbon sequestration and emission and the diverse driving factors in different areas of China, we provided guidance for future environmental policies aimed at reducing the uneven distribution of carbon sequestration and emission in different areas to achieve carbon neutralization.