Changes In Ecosystem Function Research Articles

Response of grassland ecosystem function to plant functional traits under different vegetation restoration models in areas of karst desertification.

Plant functional traits serve as a bridge between plants, the environment, and ecosystem function, playing an important role in predicting the changes in ecosystem function that occur during ecological restoration. However, the response of grassland ecosystem function to plant functional traits in the context of ecological restoration in areas of karst desertification remains unclear. Therefore, in this study, we selected five plant functional traits [namely, plant height (H), specific leaf area (SLA), leaf dry matter content (LDMC), root length (RL), and root dry matter content (RDMC)], measured these along with community-weighted mean (CWM) and functional trait diversity, and combined these measures with 10 indexes related to ecosystem function in order to investigate the differences in plant functional traits and ecosystem function, as well as the relationship between plant functional traits and ecosystem functions, under four ecological restoration models [Dactylis glomerata (DG), Lolium perenne (LP), Lolium perenne + Trifolium repens (LT), and natural grassland (NG)]. We found that: 1) the Margalef index and Shannon-Wiener index were significantly lower for plant species in DG and LP than for those in NG (P<0.05), while the Simpson index was significantly higher in the former than in NG (P<0.05); 2) CWMH, CWMLDMC, and CWMRDMC were significantly higher in DG, LP, and LT than in NG, while CWMSLA was significantly lower in the former than in NG (P<0.05). The functional richness index (FRic) was significantly higher in DG and LP than in NG and LT, but the functional dispersion index (FDis) and Rao's quadratic entropy index (RaoQ) were significantly lower in DG and LP than in NG and LT (P<0.05), and there was no significant difference between DG and LP, or between NG and LT (P>0.05); 3) ecosystem function, including ecosystem productivity, carbon storage, water conservation and soil conservation, was highest in LT and lowest in NG; and 4) CWMLDMC (F=56.7, P=0.024), CWMRL (F=28.7, P=0.024), and CWMH (F=4.5, P=0.048) were the main factors affecting ecosystem function. The results showed that the mixed pasture of perennial ryegrass and white clover was most conductive to restoration of ecosystem function. This discovery has important implications for the establishment of vegetation, optimal utilization of resources, and the sustainable development of degraded karst ecosystems.

Impacts of the accumulated extinction of endangered species on stream food webs

The world is facing a serious biodiversity-loss crisis and stream ecosystems are among the most vulnerable. Human-induced disturbances are accelerating the loss of stream biodiversity; however, their ecological impacts are poorly understood. Here, we comprehensively investigated the impact of biodiversity loss on stream food webs using massive food web data (> 1 300 webs). We analyzed the structural changes of food webs upon accumulation of biodiversity loss and specifically compared the severity of losses between fish or benthic macroinvertebrates. In particular, we focused on currently threatened and near-threatened species, to reflect realistic extinction. We simulated their sequential and accumulative extinctions and analyzed the changes in food web structural indices using a linear mixed effect model. Stream food webs tended to be robust against the loss of threatened species; however, the accumulated extinction, including both threatened and near-threatened species, caused substantial changes in food web structures. Notably, significant decreases in the number of links, link density, and generality were observed, indicating the vulnerability of the system. The loss of fish caused larger changes in the food web structure compared to that of benthic macroinvertebrates, indicating the relative importance of fish species in sustaining food web structures. Food web alteration may lead to substantial changes in ecosystem functioning. Our study suggests preemptive action to protect near-threatened species as well as threatened ones for conserving stream ecosystems and their services. Furthermore, we suggest that the food web framework is useful for diagnosing ecosystem-level impacts of species loss in biodiversity conservation.

Warming decreases desert ecosystem functioning by altering biocrusts in drylands

Abstract Warming and precipitation fluctuations are changing desert ecosystems in global drylands. However, the effects of climate change on keystone species such as cryptogamic biocrust in drylands remain relatively under‐investigated, even though biocrusts play a vital role in desert ecosystems. We conducted a long‐term experiment (14 years) to simulate the responses of two main types of biocrusts to warming coupled with reduction in precipitation that was achieved by open‐top chambers (OTCs) to simulate the predicted warming and precipitation decreasing under climate change scenario. We also conduct a structural analysis to evaluate the resulting changes in desert ecosystem functioning (carbon and nitrogen cycling). Neither warming and corresponding rainfall reduction treatments had a negative effect on lichen species richness, but both treatments reduced lichen cover and biomass. The negative effects of warming on moss‐dominated crusts were much greater than those on lichen‐dominated crusts. Although mosses and lichens had varying degree responses to warming, the loss of mosses and decreased lichen cover and biomass, as well as the shortening of the wet time, resulted in a reduction in carbon and nitrogen fixation, soil enzyme activity and water‐holding capacity of biocrusts and topsoil. These impacts collectively change the water balance of drylands and weaken the hydrological and biogeochemical function of biocrusts. Synthesis and applications: Results from this long‐term experiment suggest that the ecosystem C and N cycling and water balance of global drylands may be highly impacted by climate change, in part because of the response of biocrusts, which contribute an important implication for both dryland restoration and earth system dynamics.

Field experiments have enhanced our understanding of drought impacts on terrestrial ecosystems—But where do we go from here?

Abstract We review results from field experiments that simulate drought, an ecologically impactful global change threat that is predicted to increase in magnitude, extent, duration and frequency. Our goal is to address, from primarily an ecosystem perspective, the questions ‘What have we learned from drought experiments?’ and ‘Where do we go from here?’. Drought experiments are among the most numerous climate change manipulations and have been deployed across a wide range of biomes, although most are conducted in short‐statured, water‐limited ecosystems. Collectively, these experiments have enabled ecologists to quantify the negative responses to drought that occur for most aspects of ecosystem structure and function. Multiple meta‐analyses of responses have also enabled comparisons of relative effect sizes of drought across hundreds of sites, particularly for carbon cycle metrics. Overall, drought experiments have provided strong evidence that ecosystem sensitivity to drought increases with aridity, but that plant traits associated with aridity are not necessarily predictive of drought resistance. There is also intriguing evidence that as drought magnitude or duration increases to extreme levels, plant strategies may shift from drought tolerance to drought escape/avoidance. We highlight three areas where more drought experiments are needed to advance our understanding. First, because drought is intensifying in multiple ways, experiments are needed that address alterations in drought magnitude versus duration, timing and/or frequency (individually and interactively). Second, drivers of drought may be shifting—from precipitation deficits to rising atmospheric demand for water—and disentangling how ecosystems respond to changes in hydrological ‘supply versus demand’ is critical for understanding drought impacts in the future. Finally, more attention should be focussed on post‐drought recovery periods since legacies of drought can affect ecosystem functioning much longer than the drought itself. We conclude with a call for a fundamental shift in the focus of drought experiments from those designed primarily as ‘response experiments’, quantifying the magnitude of change in ecosystem structure and function, to more ‘mechanistic experiments’—those that explicitly manipulate ecological processes or attributes thought to underpin drought responses. Read the free Plain Language Summary for this article on the Journal blog.

Future changes in key plant traits across Central Europe vary with biogeographical status, woodiness, and habitat type

Many plant traits covary with environmental gradients, reflecting shifts in adaptive strategies and thus informing about potential consequences of future environmental change for vegetation and ecosystem functioning. Yet, the evidence of trait–environment relationships (TERs) remains too heterogeneous for reliable predictions, partially due to insufficient consideration of trait syndromes specific to certain growth forms and habitats. Moreover, it is still unclear whether non-native and native plants' traits align similarly along environmental gradients, limiting our ability to assess the impacts of future plant invasions. Using a Bayesian multilevel modelling framework, we assess TERs for native and non-native woody and herbaceous plants across six broad habitat types in Central Europe at a resolution of c. 130 km2 and use them to project trait change under future environmental change scenarios until 2081–2100. We model TERs between three key plant traits (maximum height, Hmax; specific leaf area, SLA; seed mass, SM) and individual environmental factors (7 climate variables and % urban land cover) and estimate trait change summed across all environmental effects. We also quantify the change in the average trait difference between native and non-native plants. Our models depict multiple TERs, with important differences attributed to biogeographical status and woodiness within and across habitat types. The overall magnitude of trait change is projected to be greater for non-native than native taxa and to increase under more extreme scenarios. Native woody plant assemblages may generally experience a future increase across all three traits, whereas woody non-natives may decline in Hmax and increase in SLA and SM. Herbaceous Hmax is estimated to increase and SLA to decrease in most habitats. The obtained trait projections highlight conditions of competitive advantage of non-native plants over natives and vice versa and can serve as starting points for projecting future changes in ecosystem functions and services.

Vegetation communities and summer net ecosystem CO2 exchange on western Axel Heiberg Island, Canadian High Arctic

Climate change is expected to result in the Arctic transitioning from a carbon sink to a carbon source environment, with models predicting half of the carbon stock of the upper 3 m soil layer to be released by the year 2300 (van Huissteden and Dolman 2012). However, uncertainty in latitudinal warming and changes in Arctic ecosystem functions, such as gross carbon ecosystem exchange (GEE), are poorly understood, in part a reflection of a high variability in vascular plant community diversity that is dependent upon and sensitive to physiographic controls, such as soil moisture, topography, and seasonal active layer depth (Walker et al. 2005). This heterogeneity complicates assessments of carbon fluxes on a landscape scale and how they will change in the future (Shaver et al. 2007), especially given their sensitivity to local changes in climate, such as warming and higher rates of rainfall (Bintanja 2018, Bintanja and Andry 2017). As part of the creation of a long-term ecological and environmental monitoring program at the McGill Arctic Research Station at Expedition Fiord, western Axel Heiberg Island, field-based studies in 2021-2022 of plant surveys and summer net ecosystem CO2 exchange monitoring were undertaken to: define the major vegetation communities; quantify and investigate CO2 fluxes with chambers and their analogous biophysical variables; and upscale plot level CO2 measurements to the landscape scale using high spatial resolution remote sensing data. define the major vegetation communities; quantify and investigate CO2 fluxes with chambers and their analogous biophysical variables; and upscale plot level CO2 measurements to the landscape scale using high spatial resolution remote sensing data. The Expedition Fiord area is recognized as a polar oasis, with high plant species richness existing within an environment of heterogeneous physiography. At the moment, five vegetation communities have been identified (xeric dwarf shrub barren, xeric-mesic dwarf shub barren, mesic dwarf shrub tundra, cassiope heath, and sedge meadow) that varied as a function of species diversity, percent cover, soil moisture, and net ecosystem carbon exchange. Barren vegetation communities having stronger respiration fluxes (i.e., carbon source environments) while more vegetated communities have stronger photosynthesis fluxes (i.e., carbon sink environments). Landcover classification revealed with high accuracy (79.3%) that barren ground and barren vegetation communities cover a much larger area compared to wetter habitats. Upscaling summer season measured carbon fluxes based on the landcover map revealed that Expedition Fiord is a carbon source environment, with an average efflux of +94.6 g CO2/day. Ongoing work focuses on the expansion of carbon flux and subsurface monitoring locations, as well as studies of soil carbon and microbial diversity across the different land cover classifications, which will help to better resolve how soil microorganisms, plant detritus, labile organic carbon, soil moisture, slope, aspect, and bedrock geology influence CO2 fluxes throughout the summer season in this high Arctic setting.

The efficacy of biodiversity and ecosystem assessment approaches for informing a regenerative approach to built development.

The built environment, even at its "greenest," inevitably entails changing ecosystem structure and function. Multiple sustainable development tools and approaches are available to reduce environmental harm from built development. However, the reality that society exists within fully integrated socioecological systems, wholly interdependent on supporting ecosystems, is not yet adequately represented in regulation or supporting tools. Regenerative development seeks to address this interdependence in part by improving the health of supporting socioecological systems through the development process. We demonstrate the relevance of a series of approaches-Local Nature-Related Planning Policy (LNRPP), Biodiversity Net Gain (BNG), the Environmental Benefits from Nature Tool (EBN Tool), Nature Assessment Tool for Urban and Rural Environments (NATURE Tool), and Rapid Assessment of Wetland Ecosystem Services+ (RAWES+)-for their ability to meet their stated aims and objectives and how these relate to wider regenerative themes. A comparative analysis of the five approaches is done by applying them to a practical case study site, resulting in policy- and practice-relevant learning and recommendations. The research reveals current gaps in methodology, which can lead to adverse outcomes for sustainability. This is particularly clear for the spatial and temporal scales across which each approach operates. In addition, this research discusses the inherent limitations of taking a reductionist approach to examining complex systems. Integr Environ Assess Manag 2024;20:248-262. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Spatiotemporal ecosystem services: Response to structural changes (A case study in Lahijan, Iran).

Structure and function are the inherent characteristics of each ecosystem providing various services such as clean air, extreme weather mitigation, and mental and physical well-being. The objective of this study is to develop a unified model combining Integrated Valuation of Ecosystem Services, ecological network (EN), and correlation analysis to investigate changes in ecosystem structure, function, and process. In this context, carbon sequestration, soil reduction, and flood risk mitigation were quantified from 2000 to 2020 and predicted for 2040 using the cellular automata and Markov chain (CA-Markov) model. Finally, correlation analysis was used to analyze the relationship over time between the land use (LU) classes and the components of the forest EN that provide and exchange desired ecosystem services (ESs). Thus, the changes in LU in the region in recent years led to significant reduction of ESs in the region as well as changes in the interaction between services. These changes, on the one hand, reduced the area of cores and increased isolated forest patches and, on the other hand, led to the horizontal expansion of cities and agricultural lands. If this trend continues, the decline in services provided by the ecosystem will persist into the future. Consequently, it can be said that structural changes in the ecosystem can lead to changes in the ESs. Integr Environ Assess Manag 2024;20:1099-1111. © 2023 SETAC.

Planktonic ecological networks support quantification of changes in ecosystem health and functioning

Plankton communities are the foundation of marine food webs and have a large effect on the dynamics of entire ecosystems. Changes in physicochemical factors strongly influence planktonic organisms and their turnover rates, making their communities useful for monitoring ecosystem health. We studied and compared the planktonic food webs of Palude della Rosa (Venice Lagoon, Italy) in 2005 and 2007. The food webs were developed using a novel approach based on the Monte Carlo random sampling of parameters within specific and realistic ranges to derive 1000 food webs for July of each year. The consumption flows involving Strombididae, Evadne spp. and Podon spp. were identified as the most important in splitting food webs of the July of the two years. Although functional nodes (FNs) differed both in presence and abundance in July of the two years, the whole system indicators showed very similar results. Sediment resuspension acted as a source of stress for the Venice Lagoon, being the most used resource by consumers while inhibiting primary producers by increasing water turbidity. Primary production in the water column was mainly generated by benthic FNs. Although the system was near an equilibrium point, it tended to increase its resilience at the expense of efficiency due to stress. This study highlights the role of plankton communities, which can serve to assess ecosystem health.

Soil nutrient management influences diversity, community association and functional structure of rhizosphere bacteriome under vegetable crop production.

Rhizosphere bacterial communities play a crucial role in promoting plant and soil ecosystem health and productivity. They also have great potential as key indicators of soil health in agroecosystems. Various environmental factors affect soil parameters, which have been demonstrated to influence soil microbial growth and activities. Thus, this study investigated how rhizosphere bacterial community structure and functions are affected by agronomic practices such as organic and conventional fertiliser application and plant species types. Rhizosphere soil of vegetable crops cultivated under organic and conventional fertilisers in different farms was analysed using high-throughput sequencing of the 16S rRNA gene and co-occurrence network pattern among bacterial species. The functional structure was analysed with PICRUSt2 pipeline. Overall, rhizosphere bacterial communities varied in response to fertiliser type, with soil physicochemical parameters, including NH4, PO4, pH and moisture content largely driving the variations across the farms. Organic farms had a higher diversity richness and more unique amplicon sequence variants than conventional farms. Bacterial community structure in multivariate space was highly differentiated across the farms and between organic and conventional farms. Co-occurrence network patterns showed community segmentation for both farms, with keystone taxa more prevalent in organic than conventional farms. Module hub composition and identity varied, signifying differences in keystone taxa across the farms and positive correlations between changes in microbial composition and ecosystem functions. The organic farms comprised functionally versatile communities characterised by plant growth-promoting keystone genera, such as Agromyces, Bacillus and Nocardioides. The results revealed that organic fertilisers support high functional diversity and stronger interactions within the rhizosphere bacterial community. This study provided useful information about the overall changes in soil microbial dynamics and how the changes influence ecosystem functioning under different soil nutrient management and agronomic practices.

Soil microbial diversity and network complexity drive the ecosystem multifunctionality of temperate grasslands under changing precipitation

Soil microbiomes play a critical role in regulating ecosystem multifunctionality. However, whether and how soil protists and microbiome interactions affect ecosystem multifunctionality under climate change is unclear. Here, we transplanted 54 soil monoliths from three typical temperate grasslands (i.e., desert, typical, and meadow steppes) along a precipitation gradient in the Mongolian Plateau and examined their response to nighttime warming, decreased, and increased precipitation. Across the three steppes, nighttime warming only stimulated protistan diversity by 15.61 (absolute change, phylogenetic diversity) but had no effect on ecosystem multifunctionality. Decreased precipitation reduced bacterial (8.78) and fungal (22.28) diversity, but significantly enhanced soil microbiome network complexity by 1.40. Ecosystem multifunctionality was reduced by 0.23 under decreased precipitation, which could be largely attributed to the reduced soil moisture that negatively impacted bacterial and fungal communities. In contrast, increased precipitation had little impact on soil microbial communities. Overall, both bacterial and fungal diversity and network complexity play a fundamental role in maintaining ecosystem multifunctionality in response to drought stress. Protists alter ecosystem multifunctionality by indirectly affecting microbial network complexity. Therefore, not only microbial diversity but also their interactions (regulated by soil protists) should be considered in evaluating the responses of ecosystem multifunctionality, which has important implications for predicting changes in ecosystem functioning under future climate change scenarios.

Peatland restoration increases water storage and attenuates downstream stormflow but does not guarantee an immediate reversal of long-term ecohydrological degradation

Peatland restoration is experiencing a global upsurge as a tool to protect and provide various ecosystem services. As the range of peatland types being restored diversifies, do previous findings present overly optimistic restoration expectations? In an eroding and restored upland peatland we assessed short-term (0–4 year) effects of restoration on ecohydrological functions. Restoration significantly reduced discharge from the site, transforming peat pans into pools. These retained surface water over half the time and were deeper during wet periods than before. In the surrounding haggs water tables stabilised, as drawdown during dry conditions reduced, increasing the saturated peat thickness. Despite these changes, there were no effects on photosynthesis, ecosystem respiration or dissolved organic carbon loads leaving the site. Soil respiration did not decrease as water tables rose, but methane emissions were higher from rewet pools. Restoration has had a dramatic effect on hydrology, however, consequent changes in other ecosystem functions were not measured in the 4 years after restoration. Whilst restoration is crucial in halting the expansion of degraded peatland areas, it is vital that practitioners and policymakers advocating for restoration are realistic about the expected outcomes and timescales over which these outcomes may manifest.

Trees Diversity and Species with High Ecological Importance for a Resilient Urban Area: Evidence from Cotonou City (West Africa)

Rapid urbanization and climate change effects may cause dramatic changes in ecosystem functions in cities, thereby inevitably affecting the growth performance of old trees. Few studies have explored species diversity and spatial differentiation in Benin urban areas. This study aims to explore this dimension of urban ecology in order to build resilience to climate change in the city of Cotonou. Its objective was to determine the predominant level of tree diversity in the city’s land use units. The urban green frame was subdivided into six land use units, namely, establishments, residences, green spaces, commercial areas, administrative areas, and roads. The forest inventories were carried out in 149 plots with surfaces evaluated at 2500 m2 each. The IVI, an index that highlights the relative density, relative dominance, and relative frequency of species, has been used to characterize the place occupied by each species in relation to all species in urban ecosystems. This shows ecological importance through the diversity and quality of ecosystems, communities, and species. A total of 62 tree species in 55 genera and 27 families were recorded. The results show that the flora of the city of Cotonou is characterized by a strong preponderance of exotic species with some differences in species presence. The most abundant species with high ecological importance (IVI) in the different types of land use of the city are Terminalia catappa (IVI = 121.47%), Terminalia mantaly (IVI = 90.50%), Mangifera indica (IVI = 64.06%), and Khaya senegalensis (IVI = 151.16%). As the use of ecosystem services is recommended to tackle urban climate hazards, this study shows that direct development of this urban vegetation could improve the resilience of urban life to climate hazards through the provision of urban ecosystem services, potential ecological infrastructure foundations, and urban nature-based solutions.

Trends and gaps in the study of fire effects on plant–animal interactions in Brazilian ecosystems

AbstractPlant–animal interactions are pervasive in terrestrial ecosystems. They hold relevant ecological information for guiding biodiversity conservation and restoration practices. Despite plant–animal interactions being particularly sensitive to disturbance, the knowledge about how fire, a remarkable driver of changes in ecosystem structure and functioning, affects these relationships is still limited. In this sense, the assessment of how studies investigate the fire effects on plant–animal interactions through a systematic review proves to be relevant to guide future research agenda. In this study, we reviewed studies regarding the effects of fire on plant–animal interactions conducted in Brazil, which hosts many different fire‐prone and fire‐sensitive ecosystems and harbours several plant and animal species. Supported by an integrative database, we summarized the main goals, methodologies, and taxonomic groups used in studies addressing the effects of fire on plant–animal interactions and pointed out some shortfalls that future research should avoid and gaps that they shall fulfil. In sum, 39 studies published from 1995 to 2022 met our criteria of inclusion in the database. Most of them were conducted in Cerrado and mainly evaluated ant–plant or plant–pollinator interactions. In addition, studies were generally designed with inappropriate experimental approaches that commonly disregard relevant fire attributes that are important drivers of ecosystem structure and functioning. Altogether, our review shows that studies evaluating this topic present a geographic and taxonomic bias, which overlooks particular plant–animal interactions, and that we still have a superficial understanding of fire effects on plant–animal interactions in Brazilian ecosystems.

Response of soil microbial community structure, carbon and nitrogen cycling to drying and rewetting

Global change scenarios predict that precipitation regimes will become more variable in many parts of the world, extending drought periods and increasing rainfall intensity. Under these conditions, soil microbial community composition will likely change in ways that have implications for microbially-mediated nutrient cycling. Understanding these responses is key to predicting consequential changes in ecosystem functions. A 30 day incubation experiment was used to investigate the response of microbial community structure to three different soil moisture treatments, namely, constantly moist (CM), constantly dry (CD), and drying-rewetting (DRW), in soils of three different land condition types (Remnant, Restored, and Old-field) from Para Woodlands Nature Reserve, South Australia. Soil respiration and inorganic N transformations were approximately the same across soils, despite fundamental differences in physicochemical properties, vegetation communities, and land-use history. Soil microbial community structure changed in response to the different soil moisture treatments; responses of taxa was divergent among soils. These results demonstrate that changes to soil moisture regimes under climate projections will almost certainly have consequences for soil microbial communities and C and N dynamics. The results highlight the need for further research to understand the mechanisms driving divergent responses to soil moisture, particularly in areas of different land-use types.

Temperature mediates microbial multitrophic communities assembly and soil-borne fungal pathogens in coastal ecosystems

A better understanding of assembly processes of multitrophic microbial communities and soil-borne fungal pathogens is important to predict changes in ecosystem functions. However, the drivers governing the microbial community assembly processes and soil-borne fungal pathogen distributions, particularly in the coastal ecosystem is unclear. Here, we examined the shifts in soil bacterial, fungal, protistan communities and soil-borne fungal pathogens across 2000 km in the coastal areas of eastern Australia. Determinism predominated the multitrophic microbial community assembly with mean annual temperature (MAT) differentially mediates deterministic and stochastic processes. Contrasting to protistan community, bacterial and fungal community assembly tended to be more deterministic in higher MAT regions. A total of 609 soil-borne fungal pathogens were identified with the total relative abundances ranged from 0.34 % to 52.29 % in a given soil sample. The profile of soil-borne fungal pathogens was significantly correlated with bacterial and protistan communities. Random forest indicated that MAT was the main driver of soil-borne fungal pathogens. Altogether, our work provided evidence that MAT is a critical factor driving the belowground microbial community assembly and soil-borne fungal pathogen patterns and highlighted the potential importance of trophic interactions in predicting dynamics of soil-borne fungal pathogens under the changing environment.

The microbiome structure of decomposing plant leaves in soil depends on plant species, soil pore sizes, and soil moisture content.

Microbial communities are known as the primary decomposers of all the carbon accumulated in the soil. However, how important soil structure and its conventional or organic management, moisture content, and how different plant species impact this process are less understood. To answer these questions, we generated a soil microcosm with decomposing corn and soy leaves, as well as soil adjacent to the leaves, and compared it to control samples. We then used high-throughput amplicon sequencing of the ITS and 16S rDNA regions to characterize these microbiomes. Leaf microbiomes were the least diverse and the most even in terms of OTU richness and abundance compared to near soil and far soil, especially in their bacterial component. Microbial composition was significantly and primarily affected by niche (leaves vs. soil) but also by soil management type and plant species in the fungal microbiome, while moisture content and pore sizes were more important drivers for the bacterial communities. The pore size effect was significantly dependent on moisture content, but only in the organic management type. Overall, our results refine our understanding of the decomposition of carbon residues in the soil and the factors that influence it, which are key for environmental sustainability and for evaluating changes in ecosystem functions.

Increases in functional diversity of mountain plant communities is mainly driven by species turnover under climate change

Warming in mountain regions is projected to be three times faster than the global average. Pronounced climate change will likely lead to species reshuffling in mountain plant communities and consequently change ecosystem resilience and functioning. Yet, little is known about the role of inter‐ versus intraspecific changes of plant traits and their consequences for functional richness and evenness of mountain plant communities under climate change. We performed a downslope translocation experiment of intact plant‐soil mesocosms from an alpine pasture and a subalpine grassland in the Swiss and Austrian Alps to simulate an abrupt shift in climate and removal of dispersal barriers. Translocated plant communities experienced warmer and dryer climatic conditions. We found a considerable shift from resource conservative to resource acquisitive leaf‐economy in the two climate change scenarios. However, shifts in leaf‐economy were mainly attributable to species turnover, namely colonization by novel lowland species with trait expressions for a wider range of resource use. We also found an increase in vegetative height of the warmed and drought‐affected alpine plant community, while trait plasticity to warming and drought was limited to few graminoid species of the subalpine plant community. Our results highlight the contrast between the strong competitive potential of novel lowland species in quickly occupying available niche space and native species' lack of both the intraspecific trait variability and the plant functional trait expressions needed to increase functional richness under warming and drought. This is particularly important for the trailing range of many mountain species (i.e. subalpine zone) where upward moving lowland species are becoming more abundant and abiotic climate stressors are likely to become more frequent in the near future. Our study emphasizes mountain plant communities' vulnerability to novel climates and biotic interactions under climate change and highlights graminoid species as potential winners of a warmer and dryer future.Keywords: alpine grassland, functional diversity, invasion, species turnover, traitspace, translocation

Plants alter their aboveground and belowground biomass allocation and affect community-level resistance in response to snow cover change in Central Asia, Northwest China

It is important to elucidate the changing distribution pattern of net primary productivity (NPP) to mechanistically understand the changes in aboveground and belowground ecosystem functions. In water-scarce desert environments, snow provides a crucial supply of water for plant development and the spread of herbaceous species. Yet uncertainty persists regarding how herbaceous plants' NPP allocation responds to variation in snow cover. The goal of this study was to investigate how variation in snow cover in a temperate desert influenced the NPP allocation dynamics of herbaceous species and their resistance to environmental change in terms aboveground and belowground productivity. In the Gurbantunggut Desert, wintertime snow cover depth was adjusted in plots by applying four treatments: snow removal (−S), ambient snow, double snow (+S), and triple snow (+2S). We examined their species richness, aboveground NPP (ANPP), belowground NPP (BNPP), and the resistance of ANPP and BNPP. We found that species diversity of the aboveground community increased significantly with increasing snow cover and decreased significantly Pielou evenness in plots. This resulted in greater ANPP with increasing snow cover; meanwhile, BNPP first increased and then decreased with increasing snow cover. However, this productivity in different soil layers responded differently to changed snow cover. In the 0–10 cm soil layer, productivity first rose and then declined, while it declined linearly in both the 10–20 cm and 20–30 cm soil layers, whereas in the 30–40 cm soil layer it showed an increasing trend. Belowground resistance would increase given that greater snow cover improved the BNPP in deeper soil and maintained the resource provisioning for plant growth, thus improving overall belowground stability. These results can serve as a promising research foundation for future work on how the functioning of desert ecosystems becomes altered due to changes in plant community expansion and, in particular, changes in snow cover driven by global climate change.

Ecological network-based food web dynamic model provides an aquatic population restoration strategy

Aquatic ecosystem restoration is a crucial aspect of ecological management. However, current research tends to concentrate on single factors, such as water quality or biodiversity, rather than ecological restoration strategies based on the characteristics of an ecological network system. Due to the large number of parameters to be considered, the latter approach presents still full of challenges in practical implementation. This study introduces a food web dynamic model that can guide and facilitate aquatic ecological network restoration. The model calculates the network-based interaction relationships of species in the food web, predicting the changes in ecosystem structure and function. We test our food web model by conducting a case study. The food web considered 9 kinds of species nodes, 12 links, and 1 uncertain predator–prey interaction. Our model simulations presented a strong correlation with the measured data (R2 = 0.837). We performed sensitivity analysis on 12 parameters and also conducted link prediction analysis, which revealed that there was no predator–prey relationship between species A and N (A + N = 0). By comparing population dynamics under 3 conditions, we determined that the mass reproduction of nonnative species and the population decline of native species were both related to indirect food web interactions. Finally, we comprised 27 scenarios, including fishing and stock enhancement approaches, to predict the potential restoration effects. The results showed that the fishing approach was more effective in removing alien species when the fishing frequency was shorter. It was also found that selecting catches and releasing native or endangered species back into the environment (F4, F5, F6, and F12) was necessary. On the other hand, the stock enhancement approach was concluded to be effective in increasing the number of native species as long as the frequency of enhancement was high (per 1 year, S1, S2, and S3). However, it was found to be challenging to rely on this approach to reduce the population of nonnative species. This research will enhance the previous studies in terms of (a) including whole species interactions in the ecological network; (b) considering the influence of abiotic factors, such as water quality, terrigenous carrying capacity, shoreline substrate, and hydrological connection in our model; and (c) coupling significant parameters in ecological restoration practices. This research will provide a valuable tool for managing aquatic ecological networks and decision-making suggestions for determining restoration schemes in complex aquatic food webs.