Multiple Ecosystem Research Articles

Seagrasses on the move: Tracing the multi-decadal species distribution trends in lagoon meadows using Landsat imagery

Seagrass meadows play a vital role for lagoon ecosystems and their biota, sustaining multiple ecosystem services. Their distribution and functioning are closely tied to the environmental pressures induced by global changes. Long-term monitoring of seagrass species and communities is, hence, important to depict their response to past and future scenarios. The availability of long term open-access satellite data offers a new remote sensing perspective for monitoring seagrass communities dynamics in shallow waters, especially when combined with machine learning algorithms. In this study, seasonal multispectral images (from 1999 to 2019) were collected from Landsat 5 Thematic Mapper and 8 Operational Land Imager satellites to map the seagrass meadows, at the community and species levels, within the vast Grado and Marano lagoon (Northeast Italy) using a Random Forest (RF) algorithm. RF models were calculated using an extensive field training dataset collected in 2010 (n = 426) and reached an overall accuracy of 0.92 and 0.76 for the classification at the community and species levels, respectively. The change detection analysis revealed an increase of 14.16 km2 (+ 39%) of the whole seagrass community cover over the period, at a rate of 1.59 km2year−1. Despite the coarse spatial resolution (30 m) of the Landsat's images, the classification of seagrasses at species level achieved a good overall accuracy (0.76), evidencing Nanozostera noltei as the species with the highest cover increase (+13.87 km2 over the time period). The observed expansion is likely caused by an increase of the sea water influence that is radically modifying Adriatic brackish water bodies, emphasizing the connection between the ongoing environmental changes and the rapid responses of seagrass meadows.

Reducing N fertilization in the framework of the European Farm to Fork strategy under global change: Impacts on yields, N2O emissions and N leaching of temperate grasslands in the Alpine region

ContextThe reduction of N fertilization in agriculture as part of the Farm to Fork (F2F) strategy plays a central role in the integrated nutrient management action plan of the European Commission. However, the implications of this strategy for mitigating N losses and possible side-effects on grassland yields under global change are largely unknow. ObjectiveWe examined how a 20% reduction in N fertilization according to the F2F strategy is likely to impact yields, N2O emissions and N leaching of four intensively managed temperate grasslands in the Alpine region, two of them located in Switzerland, the other two in Germany. MethodsFollowing automatic data-driven calibration supported by inverse modeling and a cross-validation step, the process-based model DayCent was used for conducting the analysis. Global change scenarios under the representative concentration pathways (RCPs) 4.5 and 8.5 and a baseline scenario (current climate) were created for the time frame 2041–2060 with the help of the stochastic weather generator LARS-WG. Results and conclusionsOur results indicated that, under current conditions of climate and CO2 levels (400 ppm), a 20% decrease in N fertilization would lead to a 5% drop in yields, but also in a 15% decline in N2O emissions and a 21% decline in N leaching (largely as NO3−). Under global change conditions (i.e., climate change and higher atmospheric CO2 levels), we found that increased yields, mainly induced by higher CO2 levels, are likely to compensate for yield losses resulting from the reduction in N fertilization. In addition, we found that the effectiveness of the F2F strategy to mitigate N losses is likely to be preserved under global change, still with stronger effect on N leaching. The F2F-induced decline in N losses was stronger when the latter were expressed per unit of harvested dry matter, i.e., up to 17% for N2O and up to 42% for N leaching. Although significant, these abatements in N losses are still below the 50% reduction level envisaged by the F2F strategy. Actions related to other axes of the strategy (e.g., sustainable food consumption) will be necessary to further reduce N fertilization and, therefore, to reach this ambitious goal. SignificanceOur results highlight the usefulness of models in accounting for interacting effects of global change and mitigation practices on multiple ecosystem services of grasslands. They allow quantification of the impact of new policies.

Contrasting mechanisms of non‐vascular and vascular plants on spatial turnover in multifunctionality in the Antarctic continent

Abstract Dominant plants play crucial roles in supporting the functioning of terrestrial ecosystems. Plants can influence the spatial heterogeneity of environmental factors, as well as the spatial turnover in the composition of soil communities (i.e. β‐diversity of soil communities). However, we still poorly understand how dominant plants drive the spatial turnover in multiple ecosystem functions (β‐multifunctionality hereafter), and to which extent the effects of dominant plants are mediated by changes in environmental heterogeneity and the β‐diversity of soil communities. Antarctica supports one of the most challenging environments on the planet including low temperature and water availability. Here, we collected soil samples under three dominant plants (lichen, moss and vascular plants) and bare ground. We measured carbon storage, nutrient availability, nutrient decomposition, microbial biomass and pathogen control to calculate β‐multifunctionality. Both non‐vascular and vascular plants were associated with increased β‐multifunctionality compared to bare ground. We further showed that lichen mainly affected β‐multifunctionality through soil temperature heterogeneity and β‐bacterial diversity. Similarly, moss mainly affected β‐multifunctionality through the spatial heterogeneity of soil water content and β‐bacterial diversity. However, vascular plants did not significantly affect environmental heterogeneity. Instead, the responses of β‐multifunctionality to vascular plants were mainly driven by the β‐diversity of soil communities. These results indicate that environmental heterogeneity is important for turnover in multiple ecosystem functions in early successional stages (dominated by non‐vascular plants), while the importance of soil communities' heterogeneity becomes more significant in late successional stages (dominated by vascular plants). Synthesis. Our findings highlight the fundamental role of dominant plants in controlling the spatial turnover in ecosystem functions, and suggest that accelerated succession under current climate warming may increase bacterial β‐diversity but decrease abiotic heterogeneity, thereby leading to both increases (e.g. regarding functions related to microbial biomass) and decreases (e.g. regarding functions related to nutrient availability) in β‐multifunctionality and hence the spatial turnover in levels of ecosystem functioning.

Regional-scale biogeographical patterns of soil extracellular enzyme activities across eight Chinese fir plantation locations

Chinese fir (Cunninghamia lanceolata) is the most important conifer tree species in plantations in subtropical China. Soil extracellular enzyme activities (EEAs) play key roles in mediating multiple forest ecosystem functions, such as organic matter decomposition, nutrient cycling, and plant productivity. In this study, the activities of five soil extracellular enzymes and their stoichiometric (EES) features were investigated at eight Chinese fir plantation locations. The results showed that the soil EEAs exhibited distinct biogeographic differences and were primarily affected by the spatial heterogeneity of soil nutrients. We found that the soil EES was strongly influenced by soil pH and mean annual temperature. Moreover, soil properties were found to be more important than climatic factors in influencing changes in soil microbial nutrient restrictions based on vector length (0.43 vs. −0.1). Random forest analysis indicated that changes in microbial nitrogen (N) and phosphorus (P) limitations were mainly affected by soil NO3−-N and dissolved organic carbon (DOC), whereas soil microbial C limitation was largely influenced by pH, DOC, and total C content. This study sheds light on how soil and climatic factors affect soil EES in subtropical Chinese fir plantation ecosystems and provides useful insights for the development of management strategies to improve the productivity of Chinese fir forests.

Driving Factors and Trade-Offs/Synergies Analysis of the Spatiotemporal Changes of Multiple Ecosystem Services in the Han River Basin, China

Uncovering the trade-offs and synergy relationship of multiple ecosystem services (ESs) is important for scientific ecosystem management and the improvement of ecological service functions. In this study, we investigated the spatiotemporal changes of four typical ES types (i.e., water yield (WY), carbon storage (CS), soil conservation (SC), and habitat quality (HQ)) from 2001 to 2020 in the Han River Basin (HRB). Meanwhile, the trade-offs and synergies between paired ESs and the socioecological drivers of these ESs were further explored. The results showed that grassland, cropland, and bare land decreased by 12,141.3 km2, 624.09 km2, and 22.1 km2 during the study period, respectively, which can be attributed to their conversion to forests in the HRB. Temporally, the WY, CS, and SC all showed a continuously increasing trend. Spatially, WY and HQ exhibited bipolar clustering characteristics, with WY exhibiting low-value clustering in the upstream and high-value clustering in the downstream, while CS showed the clustering characteristics of a scattered distribution of cold and hot spots from 2001 to 2020. The spatial patterns of aggregation locations in CS and HQ were relatively similar, with clusters of higher ES values mainly distributed in the western and central regions and clusters of lower ES values mainly located in the eastern and southeastern regions, while the aggregation of WY was spatially concentrated. Overall, the CS showed a significant positive correlation with HQ, but a significant negative correlation with WY. Spatially, WY and HQ, CS, and SC showed a substantial trade-off relationship in the northwest and southeast parts of the study area, while HQ, CS, and SC mainly exhibited a synergistic relationship in most parts of the study area. Slope and temperature had high influencing factor coefficients on multiple ESs; the mixed effect of terrain and natural factors was significantly greater than the impact of a single factor on ESs, and terrain factors played an essential role in the changes in ESs. The findings can provide technical and theoretical support for integrated scientific ecosystem management and sustainable development at the local scale.

Comparison of Carbon Storage in Forested and Non-Forested Soils in Tropical Wetlands of Caimanera, Colombia, and Llano, Mexico

Mangrove forests are considered to be the most productive ecosystems on the planet due to the multiple ecosystem services they offer, both environmental economic, and social; however, their area in recent years has been decreasing due to anthropogenic activities such as urbanization and deforestation. These activities alter the normal cycle of carbon stored in sediments, which is considered their main function to counteract climate change. Therefore, the objective of this research was to compare the carbon storage capacity and coverage in forested and non-forested sites of two tropical wetlands located in Colombia (the Caimanera) and Mexico (the Llano). Methodologically, we began by identifying the coverages and determining the area in the wetlands with Sentinel-2A satellite images and a supervised classification; subsequently, soil cores were extracted in all the coverages to a depth of 70 cm and the apparent density (AD), the percentage of organic carbon (OC), and the density of carbon in the soil were determined. For analysis of the variables, a trend graph was constructed between carbon density and depth with descriptive statistics, using one-way ANOVA to establish which coverage and wetland were the most significant concerning carbon storage. The results of the supervised classification showed that Rhizophora mangle and Avicennia germinans are the dominant species, also finding deforested areas in both wetlands. The one-way ANOVA statistical test indicated that the Caimanera, with the percentage of organic carbon (18.4 ± 1.19%), is 1.57 times greater than of the Llano mangrove swamp with (11.7 ± 0.748 MgC/ha). Through the trend graph, it was observed that the carbon density of the forested area of the Caimanera ranged from 120 to 140 MgC/ha, which is higher than in the deforested areas of the same wetland between 40 and 60 MgC/ha, and the homologous areas of the Llano wetland. The results suggest that deforested areas are sources of greenhouse gas emissions because they contain less carbon than forested areas. Therefore, it is concluded that the Caimanera and the Llano wetlands have the same mangrove species and that the average organic carbon stored in their soil is below the average of other mangrove forest soils in the American continent; it is recommended that the findings of this work be considered for the carbon balances by continent and the characterization of mangrove species according to their carbon storage capacity.

Effects of vegetation degradation on soil microbial communities and ecosystem multifunctionality in a karst region, southwest China

Vegetation degradation caused by intense human disturbances poses a significant challenge to the preservation and improvement of ecosystem functions and services in the karst region of southwest China. Soil microorganisms are major regulators of ecosystem multifunctionality (EMF). Currently, there is a dearth of knowledge regarding the effects of vegetation degradation on soil microbial communities and their corresponding multiple ecosystem functions in karst regions. In this study, we selected the vegetation degradation sequences of second natural forest (NF), agroforestry (AS) and cropland (CL) to investigate the diversity of bacterial, fungal and protistan communities, and their hierarchical co-occurrence network, and EMF to explore the relationships between them. Compared to the NF, the carbon cycling index, nitrogen cycling index, soil water regulation power, and the EMF were significantly decreased by 8.2%–50.6%, 48.7%–86.8%, 19.8%–24.5%, and 31.4%–69.5% in the AS and CL, respectively. The development of EMF can be explained by the fungal, protistan and microbial hierarchical β-diversity, as well as the complexity (e.g. degree) of microbial hierarchical interactions during the process of vegetation degradation. Notably, correlations between the abundances of sensitive amplicon sequence variants (sASVs) for different karst vegetation types and EMF varied in distinct network modules, being positive in module 1 and negative in module 2. Moreover, the relative abundance of keystone taxa in fungal and protistan communities provided greater contributions to EMF than the bacterial communities. Additionally, random forest modeling showed that carbon and nitrogen sources, and soil water content, and trace elements (e.g. exchangeable magnesium, iron, manganese, and zinc) were identified as key driving factors of the EMF. Collectively, our findings demonstrate that vegetation degradation obviously alters soil microbial diversities and hierarchical interactions, emphasizing their key role in maintaining ecosystem functions and health in karst regions.

Improving river water quality prediction with hybrid machine learning and temporal analysis

River systems provide multiple ecosystem services to society globally, but these are already degraded or threatened in many areas of the world due to water quality issues linked to diffuse and point-source pollutant inputs. Water quality evaluation is essential to develop remediation and management strategies. Computational tools such as machine learning based predictive models have been developed to improve monitoring network capabilities. The model's performance is reduced when datasets composed of reductant information are used for training, on the other hand, the selection of most representative and variable water quality scenarios could result in higher precision. This study analyzed historical water quality behavior in the Santiago River, Mexico, to identify the most variable and representative data available to train machine learning models (Adaptive Neuro Fuzzy Inference System – ANFIS, Artificial Neural Network – ANN, and Support Vector Machine - SVM). Thirteen monitoring sites were clustered according to their water quality variability from 2009 to 2022. Subsequently, a Time Series Analysis (TSA) was used to select the most representative monitoring station from each cluster. Data for 6/13 monitoring sites were retained for the Best Training Subset (BTS) used to train restricted models that performed with similar (ANN and SMV) or higher (ANFIS) prediction accuracy (in terms of RMSE, MAE, MSE and R2) for both training and testing. This study provides evidence of water quality data containing redundant information that is not useful to improve machine learning model performance, in turn leading to overtraining. Combined analytical approaches can maximize the representativeness and variability of data selected for machine learning applications, leading to improved prediction.

Supporting stakeholder dialogue on ecosystem service tradeoffs with a simulation tool for land use configuration effects

Various approaches are available to assist stakeholders in identifying and resolving ecosystem service tradeoffs. However, existing tools fall short in simulating land use configuration effects on ecosystem services and subsequently making these effects accessible to users with varying levels of expertise. To address this gap, we introduce PLACES, a tool that estimates land use impacts on multiple ecosystem services by incorporating landscape-level processes. Tool results are provided in real-time and visualized to support a dialogue between different stakeholders. This study presents the tool development and application during a mixed stakeholder workshop, after which mental models, questionnaires, and videos were analyzed to evaluate PLACES. The tool increased the participants’ understanding of insights of spatial processes and sparked discussions on the societal goals for sustainable landscapes. For future applications of PLACES, we encourage careful tailoring of the landscape representation and land use impact simulations to match the knowledge of the respective users.

Defoliation modifies the impact of drought on the transfer of recent plant-assimilated carbon to soil and arbuscular mycorrhizal fungi

Abstract Aims The allocation of recent plant photosynthates to soil via arbuscular mycorrhizal (AM) fungi is a critical process driving multiple ecosystem functions in grasslands. Yet, our understanding of how defoliation modifies below-ground allocation of recent plant photosynthate and its response to drought, which is becoming more intense and frequent, remains unresolved. Methods Here we undertook a 13C pulse-labelling experiment in a mesotrophic temperate grassland to evaluate in situ how defoliation intensity modifies the transfer of recently assimilated 13C from plant shoots to roots, extraradical AM fungal hyphae, soil, and 13C-CO2 efflux (soil respiration) in response to simulated drought. Results We found that, individually, both defoliation and drought reduced initial plant 13C uptake, but when defoliation and drought were combined, we detected a significant reduction in below-ground 13C allocation to soil. Furthermore, while defoliation stimulated 13C transfer to plant roots and soil, high intensity defoliation amplified 13C-CO2 efflux relative to the amount of 13C taken up by plants. Drought stimulated 13C transfer to fungal hyphae relative to initial plant uptake. High intensity defoliation, however, suppressed both 13C enrichment of extraradical AM fungal hyphae and 13C transfer to fungal hyphae relative to initial uptake. Conclusions Our findings suggest that defoliation can reduce the transfer of recent photosynthate below-ground under simulated drought and provide new insights into how defoliation may influence grassland C allocation dynamics and cycling between plants and AM fungi in grasslands facing drought.

Ecological restoration at pilot-scale employing site-specific rationales for small-patch degraded mangroves in Indian Sundarbans

To date, degraded mangrove ecosystem restoration accomplished worldwide primarily aligns towards rehabilitation with monotypic plantations, while ecological restoration principles are rarely followed in these interventions. However, researchers admit that most of these initiatives' success rate is not appreciable often. An integrative framework of ecological restoration for degraded mangroves where site-specific observations could be scientifically rationalized, with co-located reference pristine mangroves as the target ecosystem to achieve is currently distinctively lacking. Through this experimental scale study, we studied the suitability of site-specific strategies to ecologically restore degraded mangrove patches vis-à-vis the conventional mono-species plantations in a highly vulnerable mangrove ecosystem in Indian Sundarbans. This comprehensive restoration framework was trialed in small discrete degraded mangrove patches spanning ~ 65 ha. Site-specific key restoration components applied are statistically validated through RDA analyses and Bayesian t-tests. 25 quantifiable metrics evaluate the restoration success of a ~ 3 ha degraded mangrove patch with Ridgeline distribution, Kolmogorov–Smirnov (K-S) tests, and Mahalanobis Distance (D2) measure to prove the site’s near-equivalence to pristine reference in multiple ecosystem attributes. This restoration intervention irrevocably establishes the greater potential of this framework in the recovery of ecosystem functions and self-sustenance compared to that of predominant monoculture practices for vulnerable mangroves.

Assessing ecosystem service dynamics and drivers for sustainable management in the Agro-pastoral ecotone of northern China: A spatiotemporal analysis

To achieve regional ecological management and sustainable socio-economic development, it is essential to comprehend the intricate and interdependent relationships among various ecosystem services. The Agro-pastoral ecotone of northern China is a typical ecologically vulnerable area. There is limited research on managing multiple ecosystem services to maximize supply based on understanding the complex relationships among ecosystem services. This study used the InVEST model to quantify habitat quality (HQ), soil conservation (SC), carbon sequestration (CS), and water yield (WY) in the Agro-pastoral ecotone of northern China in 2000, 2010, and 2020 at the 5 km grid and county scales. Their trade-off and synergistic effects were explored using Spearman correlation analysis and the Geographically Weighted Regression (GWR) model. In addition, self-organizing mapping was employed to identify ecosystem service bundles at two scales, whereas the geodetector was employed to determine the primary social-ecological drivers of ES. Finally, management strategies are proposed based on the research results to promote regional ecological sustainability. The results indicate that: (1) The four ESs exhibited an increasing trend during the study period. Except for WY, the other three ES demonstrated a similar spatial distribution while remaining relatively stable over time; (2) there is a synergistic effect between CS, HQ, and SC, whereas WY-related ES show trade-off effects; (3) six ES bundles were identified at the 5 km grid scale, and four ES bundles were identified at the county scale; (4) precipitation is a major driving factor for WY and an important driving factor for CS, HQ, and SC. In summary, natural factors have a greater impact on ES than socio-economic factors. Based on the differences in ecosystem service bundles and drivers at different scales, and in conjunction with China’s existing environmental policies, corresponding ecological management strategies were proposed, potentially providing a reference for sustainable development of the Agro-pastoral ecotone in northern China.

A functional connectivity approach for exploring interactions of multiple ecosystem services in the context of agricultural landscapes in the Canadian prairies

Land-use and land-cover patterns, including their spatial heterogeneity and configuration, are fundamental in shaping landscape-level ecological processes, functions, and services. Despite growing recognition of the importance of these patterns, gaps remain in our understanding of how they influence the functional connectivity of ecosystem services (ES)—a crucial aspect for ecosystem resilience and sustainability. This research aims to bridge this gap by investigating the functional connectivity among multiple ES, such as pollination, carbon storage, soil erosion control, wetland-based ES such as habitat provisioning and water storage capacity from marshes, swamps, and open water wetlands, and agricultural food production within a complex landscape. We define functional connectivity as the extent to which the landscape facilitates or impedes the interactions and interdependencies of ecological processes that combine to create distinct ecosystem services. This definition encompasses the dynamics within a spatially interconnected mosaic of land use and land cover, exemplified by connections such as those from pollination provisioning areas to croplands. The primary goal of this research is to develop an empirical framework that encapsulates ‘network topological’ interactions— essentially, the complex interplay among various components of the ecosystem — specific to agricultural landscapes and then to apply this framework to the Canadian prairies. Our methodology uses the spatial tools including InVEST, ARIES, and GIS to map diverse ES. An ecological network is then constructed for these ES at the landscape scale, designating network nodes based on high-value ES provisioning areas and defining links between pairs of ES according to their functional connections (overlapping and proximal in physical space). These functional connections effectively delineate areas of the landscape where the majority of ES flows occur. Mapping ES connectivity and network building revealed that around 29% of the studied landscape lies within functional connectivity zones for the selected ES, representing hotspots of significant ES interactions. Our findings reveal that although soil erosion-control spans just 1.36% of the total area, a substantial 72.59% of its spatial extent was identified as functionally connected. Land cover analysis in functional connectivity zones revealed that natural habitats such as shrublands, broadleaf forests, wetlands, and grasslands are vital mediators of ES. The variability in ES interconnectivity in the landscape was evident both in the intensity of interactions and observed connections. Our findings, informed by Ecological Network Analysis (ENA), emphasize the need for integrating connectivity and systems thinking in conservation sciences to achieve sustainability and ecosystem resilience. The insights offer a foundation to explore optimal ES provisioning scenarios at the landscape scale.

Stand structural effects on growth distribution and growth efficiency in Scots pine and Mediterranean pine in Spain

AbstractUnderstanding the growth efficiency of individual trees, or growth per unit of resource utilization, can inform silvicultural management strategies to maximize tree and stand growth. Stand structure—the size and spatial distributions of trees within the stand—strongly influences water, light, and nutrient availability, as well as the resource-use efficiency of each tree. Key silvicultural tools for stand management include manipulating tree density, size distribution, and arrangement by controlling natural regeneration, artificial seeding, planting seedlings, and/or subsequent thinning of established trees. We analyzed two sets of plots from even-aged stands of common coniferous species in central Spain, 106 pure Scots pine (Pinus sylvestris) and 92 pure Mediterranean pine (Pinus pinaster), to examine the dynamics of the dominance hypothesis, the relationship between stand structure and growth, and the relationship between structure and growth efficiency. Our main findings revealed a negative impact of size-class uniformity on stand growth in both Scots pine and Mediterranean pine, while the positive effect of tree size on growth efficiency was supported for Mediterranean pine stands but uncertain for Scots pine. At the operational level, our results highlight how thinning intensity is more important than the thinning method in Mediterranean pinewoods and how thinning can benefit the provision of multiple ecosystem services. We also recommend integrating dominance effects on growth into individual tree modelling.

Stand spatial structure and microbial diversity are key drivers of soil multifunctionality during secondary succession in degraded karst forests

Studying the relationship between biodiversity and ecosystem multifunctionality (the ability of ecosystems to provide multiple ecosystem functions) (BEMF) is a current hotspot in ecology research. Previous studies on BEMF emphasized the role of plant and microbial diversity but rarely mention stand spatial structure. To investigate the effect of stand spatial structure on BEMF, this study established 30 forest dynamic plots in three natural restoration stages (shrubbery, secondary growth forest, and old-growth forest) in Maolan National Nature Reserve, Guizhou province, China. A positive response in soil multifunctionality (SMF), plant species diversity, stand spatial structure, and fungal β diversity (p < 0.05) followed natural restoration. However, bacterial β diversity showed a negative response (p < 0.05), while microbial α diversity remained unchanged (p > 0.05). These results based on a structural equation model showed that plant species diversity had no direct or indirect effect on SMF, soil microbial diversity was the only direct driver of SMF, and stand spatial structure indirectly affected SMF through soil microbial diversity. The random forest model showed that soil microbial β diversity and the Shannon-Wiener index of the diameter at breast height for woody plant species were the optimal variables to characterize SMF and soil microbial diversity, respectively. These results suggested that natural restoration promoted SMF, and microbial diversity had a direct positive effect on SMF. In the meantime, stand spatial structure had a significant indirect effect on SMF, while plant species diversity did not. Future work on degraded karst forest restoration should direct more attention to the role of the stand spatial structure and emphasize the importance of biodiversity.

Soil erosion‐induced decline in aggregate stability and soil organic carbon reduces aggregate‐associated microbial diversity and multifunctionality of agricultural slope in the Mollisol region

AbstractSoil erosion has become a serious ecological problem hindering the agricultural and economic development in Northeast China. Soil aggregates are basic units that regulate soil fertility and microbial activity. However, there have been few reports on the role of soil erosion in regulating the microbial diversity, multiple ecosystem services, and functions (multifunctionality) of soil aggregates. In this study, we investigated the effects of soil erosion on microbial diversity and the activities of various extracellular enzymes associated with soil aggregates by using Mollisol soil in Northeastern China at different positions of a slope, and how soil erosion affects soil multifunctionality indexes obtained by normalized calculation of soil enzyme activities. The results showed that soil erosion could reduce the physicochemical properties, soil enzyme activity, and microbial diversity of the aggregates, resulting in accumulation of aggregate nutrients and increase in microbial diversity and enzyme activity in the sedimentation area. Compared with smaller soil aggregates, larger soil aggregates had higher nutrient content, enzyme activity, and microbial diversity. However, with the intensification of soil erosion, the differences in microbial diversity and soil enzyme activities among different sizes of aggregates were reduced. Soil erosion also significantly reduced soil multifunctionality (p &lt; 0.001). The multifunctionality of 2000–250 μm, 250–53 μm, and &lt;53 μm aggregates respectively declined from 0.52, 0.20, and 0.08 (no erosion sites) to −0.17, −0.66, and −0.77 (heavy erosion sites). Additionally, microbial diversity was found to have a linear positive correlation with soil multifunctionality (R2 = 0.23, p &lt; 0.01). Structural equation modeling and random forest analysis revealed that soil organic carbon and aggregate water stability are main predictors of soil multifunctionality. Furthermore, soil physicochemical properties had a greater influence on soil multifunctionality than microbial diversity. Collectively, our results demonstrate that soil erosion negatively affects the structure, resource effectiveness, and microbial activity of soil aggregates, thereby reducing to differential soil multifunctionality.

Bridging biodiversity and gardening: Unravelling the interplay of socio-demographic factors, garden practices, and garden characteristics

The expansion of urban areas threatens biodiversity and disrupts ecological relationships, thereby impeding key ecosystem services. To avert irreversible consequences, there is a focus on improving the biodiversity value of domestic gardens. We employ machine learning and network analysis and examine gardening practices and garden owners’ environmental consciousness in Hungary through a questionnaire-based study to untangle the interplay among socio-demographic factors, garden management and -characteristics. We found that the activities determined as biodiversity-positive were widespread among respondents, but ubiquitous pesticide use (62.14%), lack of undisturbed areas (49.52%), and frequent mowing (32.06%) were also present. Middle-aged respondents demonstrated more biodiversity-supporting activities than those over 55, who had long-term gardening experience and were predominantly conventional gardeners. Respondents of towns showed the least biodiversity-positive activities, whereas those living in cities and the countryside fared better. Additionally, multiple interconnected garden characteristics revealed various types of gardens distinguished by care practices and use, such as gardens for food self-provisioning, ornamental gardens, or those prioritizing biodiversity support. Our results show that garden owners use pesticides independently of socio-demographic parameters, gardening practices, or garden characteristics, suggesting widespread pesticide use in Hungary. Our findings suggest that strategies to promote biodiversity-friendly gardening may not be equally suitable for all gardener owners with different cultural backgrounds, environmental consciousness and gardening habits. Factors like differences between societal groups underscore the preference for in-person programs over online information transfer in several cases, for instance, among the elderly and those living in the countryside. We offer fresh perspectives on the intricate connections between garden diversity, characteristics, and practices, and it lays the groundwork for future research into the sociological drivers of gardening practices in Eastern Europe. Our work emphasises that optimizing gardens for multiple ecosystem services, including biodiversity conservation and enhancing human well-being, requires a nuanced understanding of both ecological and socio-demographic factors.

Trade-offs between nitrogen and phosphorus removal with floodplain remediation in agricultural streams

To improve water quality and reduce instream erosion, floodplain remediation along agricultural streams can provide multiple ecosystem services through biogeochemical and fluvial processes. During floodplain inundation, longer water residence time and periodic anoxic conditions can lead to increased nitrogen (N) removal through denitrification but also mobilization of phosphorus (P), impeding overall water quality improvements. To investigate the capacity for N and P processing in remediated streams, we measured potential denitrification and nitrous oxide production and yields together with potential P desorption and P fractions in floodplain and stream sediments in ten catchments in Sweden. Sediment P desorption was measured as equilibrium P concentration, using P isotherm incubations. Denitrification rates were measured with the acetylene inhibition method. Sediment nutrient process rates were combined with hydrochemical monitoring along remediated streams and their paired upstream control reaches of trapezoidal shape to determine the impact of floodplains on water quality. The correlation between floodplain denitrification rates and P desorption (r = 0.53, p = 0.02) revealed a trade-off between soluble reactive P (SRP) and nitrate removal, driven by stream water connectivity to floodplains. Nitrous oxide production was not affected by differences in P processing, but nitrous oxide yields decreased with higher denitrification and P desorption. The release of SRP from floodplains (0.03 ± 0.41 mg P kg−1 day−1) was significantly lower than from trapezoidal stream banks (0.38 ± 0.37 mg P kg−1 day−1), predicted by long-term SRP concentrations in stream water and floodplain inundation frequency. The overall impact of SRP release from floodplains on stream SRP concentrations in remediated reaches was limited. However, the remediated reaches showing increased stream SRP concentrations were also frequently inundated and had higher labile P content and coarse soil texture in floodplain sediments. To fully realize the potential for water quality improvements with constructed floodplains in agricultural streams, the promotion of denitrification through increased inundation should be balanced against the risk of P release from sediments, particularly in streams with high SRP inputs.

Evaluating dynamic tree-species-shifting and height development caused by ungulate browsing in forest regeneration using a process-based modeling approach

Ungulate browsing can prevent the successful regeneration and development of forest-owner-intended and climate-resilient admixed tree species, compromising the future provision of multiple ecosystem services. A reduction of the height increment of palatable tree species caused by ungulate browsing results in a competition shift in favor of less palatable species. While this key process of losing admixed tree species is well understood, forest growth models have not yet captured its full complexity. Therefore, our objectives were to simulate (i) the loss of susceptible tree species from different browsing regimes and its impact on stand development, (ii) changes in the height increment of saplings and trees, and (iii) the shifts in social status during stand development without pre-defined limits a sapling can resist browsing. To address these objectives, we used the process-based model iLand to simulate the exposure of Norway spruce, Silver fir, and European beech stands to varying browsing densities. We successfully reproduced expected dynamic shifts in species composition and height development 24 years after establishment, depending on ungulate pressure and species-specific competitive strength. Stand composition and growth differences already occur with slight changes in ungulate density. When saplings remained in stand structure, independent of the number being browsed, our results led to more individuals with substantially smaller dimensions. We found that dynamic tree species shifting can be simulated realistically by a process-based modeling approach, which can be used to show the strong impact of ungulates on stand development.

Determinants of Farmers’ Perceptions towards Socioecological Benefits of Agroforestry Practices in Northwestern Ethiopia

Agroforestry practices provide multiple ecosystem services in agricultural landscapes. However, within the local context, local communities hold divergent perceptions regarding the various roles of agroforestry, particularly in the Afrotropical Region. Hence, understanding these drivers is critical for adopting and promoting sustainable agroforestry practices. Here, we examined the factors that influenced farmers’ perceptions towards the socioecological benefits of agroforestry practices. A multistage stratified random sampling technique was applied to select 90 households along an urban-rural gradient. The data were gathered through semi-structured questionnaires and key informant interviews and analyzed using a descriptive statistics, chi-square tests, general linear model, and redundancy analysis with the help of R software version 4.3.2. The findings showed that approximately 69.7% of the respondents strongly agreed that agroforestry practices had benefits for society and the environment. However, 11.1% were neutral, and the others disagreed. The results of the general linear model analysis showed that household age, agricultural experience, access to land certification books, and training on tree conservation had a significantly positive effect on farmers’ perceptions of the advantages of agroforestry practices. Furthermore, farmers’ perceptions of the benefits of agroforestry in terms of income generation, educational and cultural values, and climate change mitigation were dependent on household age and farming experience. Overall, this study provides useful insights into the drivers of farmers’ perceptions of the advantages of agroforestry practices in Northwest Ethiopia. The findings of this study underscore the need for policymakers and practitioners to consider sociodemographic and institutional factors that influence farmers’ perceptions when developing policies and plans to advance the adoption and promote sustainable management of agroforestry practices. This supports the widespread adoption of agroforestry practices in tropical agroecosystems.