For flux's sake: General considerations for energy‐flux calculations in ecological communities

Global change alters ecological communities with consequences for ecosystem processes. Such processes and functions are a central aspect of ecological research and vital to understanding and mitigating the consequences of global change, but also those of other drivers of change in organism communities. In this context, the concept of energy flux through trophic networks integrates food‐web theory and biodiversity‐ecosystem functioning theory and connects biodiversity to multitrophic ecosystem functioning. As such, the energy‐flux approach is a strikingly effective tool to answer central questions in ecology and global‐change research. This might seem straight forward, given that the theoretical background and software to efficiently calculate energy flux are readily available. However, the implementation of such calculations is not always straight forward, especially for those who are new to the topic and not familiar with concepts central to this line of research, such as food‐web theory or metabolic theory. To facilitate wider use of energy flux in ecological research, we thus provide a guide to adopting energy‐flux calculations for people new to the method, struggling with its implementation, or simply looking for background reading, important resources, and standard solutions to the problems everyone faces when starting to quantify energy fluxes for their community data. First, we introduce energy flux and its use in community and ecosystem ecology. Then, we provide a comprehensive explanation of the single steps towards calculating energy flux for community data. Finally, we discuss remaining challenges and exciting research frontiers for future energy‐flux research.     

Mesocosms Reveal Ecological Surprises from Climate Change

Understanding, predicting, and mitigating the impacts of climate change on biodiversity poses one of the most crucial challenges this century. Currently, we know more about how future climates are likely to shift across the globe than about how species will respond to these changes. Two recent studies show how mesocosm experiments can hasten understanding of the ecological consequences of climate change on species’ extinction risk, community structure, and ecosystem functions. Using a large-scale terrestrial warming experiment, Bestion et al. provide the first direct evidence that future global warming can increase extinction risk for temperate ectotherms. Using aquatic mesocosms, Yvon-Durocher et al. show that human-induced climate change could, in some cases, actually enhance the diversity of local communities, increasing productivity. Blending these theoretical and empirical results with computational models will improve forecasts of biodiversity loss and altered ecosystem processes due to climate change.     

水生态系统中宇宙发展现状

水生态系统中宇宙指人工构建的河流、湖泊、湿地、海洋等水生态系统近自然模拟装置,可以控制一定的物理、化学要素和生境条件,开展生物群落响应研究。中宇宙实验可以弥补传统实验室小型装置模拟要素过于简单,而野外现实系统复杂不可控制和难以开展对比实验的局限。本文列举了当前国际上多个科研机构长期运行的水生态系统中宇宙,将其归纳为流水型中宇宙、围隔装置、陆基模拟池、移动式水槽4类,各类中宇宙一般包括物理-生物模拟系统、自动调控系统、监测分析系统、中央控制系统。近年来,我国水生态系统的研究逐渐从单一环境要素向生态系统整体转变,对中宇宙模拟实验的需求愈加迫切。建议我国水生态系统中宇宙建设应提高结构复杂性,并与野外现场监测相结合,共同支撑更大尺度系统的整体模拟。     

The Beauty is a beast: Does leachate from the invasive terrestrial plant Impatiens glandulifera affect aquatic food webs?

Invasive alien species are a major threat to ecosystems. Invasive terrestrial plants can produce allelochemicals which suppress native terrestrial biodiversity. However, it is not known if leached allelochemicals from invasive plants growing in riparian zones, such as Impatiens glandulifera, also affect freshwater ecosystems. We used mesocosms and laboratory experiments to test the impact of I. glandulifera on a simplified freshwater food web. Our mesocosm experiments show that leachate from I. glandulifera significantly reduced population growth rate of the water flea Daphnia magna and the green alga Acutodesmus obliquus, both keystone species of lakes and ponds. Laboratory experiments using the main allelochemical released by I. glandulifera, 2‐methoxy‐1,4‐naphthoquinone, revealed negative fitness effects in D. magna and A. obliquus. Our findings show that allelochemicals from I. glandulifera not only reduce biodiversity in terrestrial habitats but also pose a threat to freshwater ecosystems, highlighting the necessity to incorporate cross‐ecosystem effects in the risk assessment of invasive species.     

Structural and functional development of twelve newly established floodplain pond mesocosms

Ecosystems are complex structures with interacting abiotic and biotic processes evolving with ongoing succession. However, limited knowledge exists on the very initial phase of ecosystem development and colonization. Here, we report results of a comprehensive ecosystem development monitoring for twelve floodplain pond mesocosms (FPM; 23.5 m × 7.5 m × 1.5 m each) located in south‐western Germany. In total, 20 abiotic and biotic parameters, including structural and functional variables, were monitored for 21 months after establishment of the FPMs. The results showed evolving ecosystem development and primary succession in all FPMs, with fluctuating abiotic conditions over time. Principal component analyses and redundancy analyses revealed season and succession time (i.e., time since ecosystem establishment) to be significant drivers of changes in environmental conditions. Initial colonization of both aquatic (i.e., water bodies) and terrestrial (i.e., riparian land areas) parts of the pond ecosystems occurred within the first month, with subsequent season‐specific increases in richness and abundance for aquatic and terrestrial taxa over the entire study period. Abiotic environmental conditions and aquatic and terrestrial communities showed increasing interpond variations over time, that is, increasing heterogeneity among the FPMs due to natural environmental divergence. However, both functional variables assessed (i.e., aquatic and terrestrial litter decomposition) showed opposite patterns as litter decomposition rates slightly decreased over time and interpond differences converged with successional ecosystem developments. Overall, our results provide rare insights into the abiotic and biotic conditions and processes during the initial stages of freshwater ecosystem formation, as well as into structural and functional developments of the aquatic and terrestrial environment of newly established pond ecosystems.     

The functional role and diversity of soil nematodes are stronger at high elevation in the lesser Himalayan Mountain ranges

Soil nematodes are a foremost component of terrestrial biodiversity; they display a whole gamut of trophic guilds and life strategies, and by their activity, affect major ecosystem process, such as organic matter degradation and carbon cycling. Based on nematodes'' functional types, nematode community indices have been developed, and can be used to link variation in nematodes community composition and ecosystem processes. Yet, the use of these indices has been mainly restricted to anthropogenic stresses. In this study, we propose to expand the use of nematodes'' derived ecological indices to link soil and climate properties with soil food webs, and ecosystem processes that all vary along steep elevation gradients. For this purpose, we explored how elevation affects the trophic and functional diversity of nematode communities sampled every 300 m, from about 1,000 m to 3,700 m above sea level, across four transects in the lesser Himalayan range of Jammu and Kashmir. We found that (a) the trophic and functional diversity of nematodes increases with elevation; (b) differences in nematodes communities generate habitat‐specific functional diversity; (c) the maturity index (ΣMI) increases with elevation, while the enrichment index decreases, indicating less mature and less productive ecosystems, enhanced fungal‐based energy flow, and a predominant role of nematodes in generating carbon influxes at high‐elevation sites. We thus confirm that the functional contribution of soil nematodes to belowground ecosystem processes, including carbon and energy flow, is stronger at high elevation. Overall, this study highlights the central importance of nematodes in sustaining soil ecosystems and brings insights into their functional role, particularly in alpine and arctic soils.     

Tracking sucking herbivory with nitrogen isotope labelling: Lessons from an individual trait-based approach

Response and effect traits help to understand how changes in ecological communities (e.g. in response to land use) relate to changes in ecosystem functioning. In grasslands, plants and insect herbivores are involved in many ecosystem processes such as herbivory and plant biomass production. Simultaneous changes in the trait composition of both plants and herbivores should affect herbivory rates, with consequences for plant growth and potentially biomass production. The mechanisms underlying these links are little understood for grasses and sucking insects, which build a major part of grassland communities. In a mesocosm experiment, we manipulated the composition of grasses and sucking herbivores (Hemiptera) to study the role of plant traits, herbivore traits and their interaction on herbivory and plant growth. Because sucking herbivory is generally difficult to quantify, we developed a novel experimental setting, in which we labelled plants with ¹⁵N isotope. This allowed to quantify ¹⁵N uptake and thus sucking rates of individuals. We found that herbivory and simultaneous plant growth reduction are most strongly linked to herbivore species identity. Unexpectedly, herbivory did not increase with herbivore size, but was highest for small species and for thin-bodied Heteroptera. Additionally, herbivory and plant growth reduction depended on the interacting herbivore and plant species, indicating trait matching, which could, however, not be explained with commonly used traits. This indicates that mechanisms linking ecological communities and ecosystem processes are highly context-specific. To understand how global change affects ecosystem functioning, studies need to cover all functionally relevant groups, including plant sap suckers.     

Offshore platforms as novel ecosystems: A case study from Australia’s Northwest Shelf

The decommissioning of offshore oil and gas platforms typically involves removing some or all of the associated infrastructure and the consequent destruction of the associated marine ecosystem that has developed over decades. There is increasing evidence of the important ecological role played by offshore platforms. Concepts such as novel ecosystems allow stakeholders to consider the ecological role played by each platform in the decommissioning process. This study focused on the Wandoo field in Northwest Australia as a case study for the application of the novel ecosystem concept to the decommissioning of offshore platforms. Stereo‐baited remote underwater video systems were used to assess the habitat composition and fish communities at Wandoo, as well as two control sites: a sandy one that resembled the Wandoo site pre‐installation, and one characterized by a natural reef as a control for natural hard substrate and vertical relief. We found denser macrobenthos habitat at the Wandoo site than at either of the control sites, which we attributed to the exclusion of seabed trawling around the Wandoo infrastructure. We also found that the demersal and pelagic taxonomic assemblages at Wandoo more closely resemble those at a natural reef than those which would likely have been present pre‐installation, but these assemblages are still unique in a regional context. The demersal assemblage is characterized by reef‐associated species with higher diversity than those at the sand control and natural reef control sites, with the pelagic community characterized by species associated with oil platforms in other regions. These findings suggest that a novel ecosystem has emerged in the Wandoo field. It is likely that many of the novel qualities of this ecosystem would be lost under decommissioning scenarios that involve partial or complete removal. This study provides an example for classifying offshore platforms as novel ecosystems.     

Do soil depth and plant community composition interact to modify the resistance and resilience of grassland ecosystem functioning to drought?

While the effect of drought on plant communities and their associated ecosystem functions is well studied, little research has considered how responses are modified by soil depth and depth heterogeneity. We conducted a mesocosm study comprising shallow and deep soils, and variable and uniform soil depths, and two levels of plant community composition, and exposed them to a simulated drought to test for interactive effects of these treatments on the resilience of carbon dioxide fluxes, plant functional traits, and soil chemical properties. We tested the hypotheses that: (a) shallow and variable depth soils lead to increased resistance and resilience of ecosystem functions to drought due to more exploitative plant trait strategies; (b) plant communities associated with intensively managed high fertility soils, will have more exploitative root traits than extensively managed, lower fertility plant communities. These traits will be associated with higher resistance and resilience to drought and may interact with soil depth and depth heterogeneity to amplify the effects on ecosystem functions. Our results showed that while there were strong soil depth/heterogeneity effects on plant‐driven carbon fluxes, it did not affect resistance or resilience to drought, and there were no treatment effects on plant‐available carbon or nitrogen. We did observe a significant increase in exploitative root traits in shallow and variable soils relative to deep and uniform, which may have resulted in a compensation effect which led to the similar drought responses. Plant community compositions representative of intensive management were more drought resilient than more diverse “extensive” communities irrespective of soil depth or soil depth heterogeneity. In intensively managed plant communities, root traits were more representative of exploitative strategies. Taken together, our results suggest that reorganization of root traits in response to soil depth could buffer drought effects on ecosystem functions.     

Extreme storms cause rapid but short-lived shifts in nearshore subtropical bacterial communities

Climate change scenarios predict tropical cyclones will increase in both frequency and intensity, which will escalate the amount of terrestrial run-off and mechanical disruption affecting coastal ecosystems. Bacteria are key contributors to ecosystem functioning, but relatively little is known about how they respond to extreme storm events, particularly in nearshore subtropical regions. In this study, we combine field observations and mesocosm experiments to assess bacterial community dynamics and changes in physicochemical properties during early- and late-season tropical cyclones affecting Okinawa, Japan. Storms caused large and fast influxes of freshwater and terrestrial sediment – locally known as red soil pollution – and caused moderate increases of macronutrients, especially SiO₂ and PO₄³⁻, with up to 25 and 0.5 μM respectively. We detected shifts in relative abundances of marine and terrestrially derived bacteria, including putative coral and human pathogens, during storm events. Soil input alone did not substantially affect marine bacterial communities in mesocosms, indicating that other components of run-off or other storm effects likely exert a larger influence on bacterial communities. The storm effects were short-lived and bacterial communities quickly recovered following both storm events. The early- and late-season storms caused different physicochemical and bacterial community changes, demonstrating the context-dependency of extreme storm responses in a subtropical coastal ecosystem.     

Recognizing cross‐ecosystem responses to changing temperatures: soil warming impacts pelagic food webs

The energy and materials that move across ecosystem boundaries influence food web structure and key ecosystem functions. Despite the acknowledged importance of such ecological subsidies, surprisingly little information is available regarding the role of environmental temperature in influencing subsidy quality and the response of the recipient ecosystem. We evaluated the impacts of temperature‐mediated changes in leaves from deciduous trees, an important subsidy from terrestrial to freshwater ecosystems, on both the producer‐based and detritivore‐based components of a pelagic pond food web in a field mesocosm experiment. We hypothesized that variation in leaf chemistry driven by increased soil temperature would alter both the quality of leaf subsidies and the pond response. We collected red maple Acer rubrum leaves from heated and ambient temperature plots from the long‐term soil warming experiment at the Harvard Experimental Forest and added them to 167‐l field mesocosms containing established plankton communities, creating ‘no leaf’, ‘ambient leaf’ and ‘heated leaf’ treatments during autumn 2012. We then monitored physical, chemical, and biological responses to treatments until the mesocosms froze six weeks later. Experimental soil warming altered the chemical composition of deciduous leaves, the physical and chemical environment of the aquatic ecosystems to which leaves were added, and the pelagic pond food webs as measured by community composition. Compared to leaves from ambient‐temperature soils, leaves from warmed soils initially resulted in lower water column phosphorus and dissolved organic carbon, reducing bacterial densities. However, the diminished carbon and phosphorus resulting from soil warming also increased light availability that ultimately stimulated cladoceran zooplankton relative to ambient‐temperature leaves. Our results suggest that changes in temperature can alter ecological subsidies in unanticipated ways, and suggest that accurately predicting the potential consequences of climate change will require conducting research across ecosystem boundaries.     

Community size structure varies with predator–prey size relationships and temperature across Australian reefs

Climate change and fisheries exploitation are dramatically changing the abundances, species composition, and size spectra of fish communities. We explore whether variation in ‘abundance size spectra’, a widely studied ecosystem feature, is influenced by a parameter theorized to govern the shape of size‐structured ecosystems—the relationship between the sizes of predators and their prey (predator–prey mass ratios, or PPMRs). PPMR estimates are lacking for avast number of fish species, including at the scale of trophic guilds. Using measurements of 8128 prey items in gut contents of 97 reef fish species, we established predator–prey mass ratios (PPMRs) for four major trophic guilds (piscivores, invertivores, planktivores, and herbivores) using linear mixed effects models. To assess the theoretical predictions that higher community‐level PPMRs leads to shallower size spectrum slopes, we compared observations of both ecosystem metrics for ~15,000 coastal reef sites distributed around Australia. PPMRs of individual fishes were remarkably high (median ~71,000), with significant variation between different trophic guilds (~890 for piscivores; ~83,000 for planktivores), and ~8700 for whole communities. Community‐level PPMRs were positively related to size spectrum slopes, broadly consistent with theory, however, this pattern was also influenced by the latitudinal temperature gradient. Tropical reefs showed a stronger relationship between community‐level PPMRs and community size spectrum slopes than temperate reefs. The extent that these patterns apply outside Australia and consequences for community structure and dynamics are key areas for future investigation.     

土壤线虫对气候变化的响应研究进展

全球变化对陆地生态系统功能具有重要而深远的影响。陆地生态系统地下部分具有重要的生态功能,其组成及结构对气候变化的响应将进一步减缓或加剧全球化进程。土壤线虫在各类生态系统中分布十分广泛,是地下食物网的重要组分,在维持土壤生物多样性及营养物质循环过程中发挥重要作用,其组成及结构对不同气候变化驱动因子的响应机制与模式不尽相同。增温及降水格局变化主要是通过改变线虫生境而直接影响其种群密度与结构,两者通常表现为正效应且作用效果随处理时间的延长而增强。CO2与大气氮沉降主要是通过影响地上植被,凋落物质量,土壤理化性质等间接过程影响土壤线虫。同时,不同的全球变化因子之间存在着复杂的交互作用,深入理解这些因子之间交互作用对线虫群落的影响模式与机制对于探讨未来气候变化情景下生态统生物多样性及养分循环过程具有重要的理论指导意义。     

Impacts of environmental stress on resistance and resilience of algal‐associated bacterial communities

Algal‐associated bacteria are fundamental to the ecological success of marine green macroalgae such as Caulerpa. The resistance and resilience of algal‐associated microbiota to environmental stress can promote algal health and genetic adaptation to changing environments. The composition of bacterial communities has been shown to be unique to algal morphological niches. Therefore, the level of response to various environmental perturbations may in fact be different for each niche‐specific community. Factorial in situ experiments were set up to investigate the effect of nutrient enrichment and temperature stress on the bacterial communities associated with Caulerpa cylindracea. Bacteria were characterized using the 16S rRNA gene, and the community compositions were compared between different parts of the algal thallus (endo‐, epi‐, and rhizomicrobiome). Resistance and resilience were calculated to further understand the changes of microbial composition in response to perturbations. The results of this study provide evidence that nutrient enrichment has a significant influence on the taxonomic and functional structure of the epimicrobiota, with a low community resistance index observed for both. Temperature and nutrient stress had a significant effect on the rhizomicrobiota taxonomic composition, exhibiting the lowest overall resistance to change. The functional performance of the rhizomicrobiota had low resilience to the combination of stressors, indicating potential additive effects. Interestingly, the endomicrobiota had the highest overall resistance, yet the lowest overall resilience to environmental stress. This further contributes to our understanding of algal microbiome dynamics in response to environmental changes.     

Biodiversity and ecosystem functioning in food webs: the vertical diversity hypothesis

One challenge in merging community and ecosystem ecology is to integrate the complexity of natural multitrophic communities into concepts of ecosystem functioning. Here, we combine food‐web and allometry theories to demonstrate that primary production, as measured by the total nutrient uptake of the multitrophic community, is determined by vertical diversity (i.e. food web's maximum trophic level) and structure (i.e. distributions of species and their abundances and metabolic rates across trophic levels). In natural ecosystems, the community size distribution determines all these vertical patterns and thus the total nutrient uptake. Our model suggests a vertical diversity hypothesis (VDH) for ecosystem functioning in complex food webs. It predicts that, under a given nutrient supply, the total nutrient uptake increases exponentially with the maximum trophic level in the food web and it increases with its maximum body size according to a power law. The VDH highlights the effect of top–down regulation on plant nutrient uptake, which complements traditional paradigms that emphasised the bottom–up effect of nutrient supply on vertical diversity. We conclude that the VDH contributes to a synthetic framework for understanding the relationship between vertical diversity and ecosystem functioning in food webs and predicting the impacts of global changes on multitrophic ecosystems.     

Can artificial ecological islands alter the biodiversity of macroinvertebrate? A case study in Fujin National Wetland Park,the Sanjiang Plain,China

1. Many policies and studies globally have highlighted the pivotal role of wetland ecosystems regarding wetland biota and their ecological status. With the strengthening of wetland ecosystem management legislation and policy, wetland restoration should also consider increasing habitat diversity to improve biota. We explore whether the construction of artificial ecological islands can increase the diversity of and macroinvertebrates before assessing the effects of actively constructing islands via human intervention on wetland protection.
2. We discuss changes in macroinvertebrate diversity (i) with and without islands, (ii) at different water‐level gradients surrounding the islands, (ⅲ) on different island substrates, and (ⅳ) at different time scales. We used ANOVA, ANOSIM, and cluster analysis to test the differences.
3. The macroinvertebrate communities had spatially heterogeneous distributions which changes over time due to both natural and anthropogenic stresses. The establishment of islands significantly increased the community composition and biodiversity of the macroinvertebrate. Water depth and substrate affect community composition of macrozoobenthos. The abundance and diversity of macroinvertebrates can influence the biodiversity of their predators (fish and waterbirds). Potentially, the construction of islands could provide some cobenefits for the conservation of wetland fauna.

Synthesis and applications. Establishing artificial ecological islands in broad open‐water areas and increasing water‐level gradient and substrate diversity can increase microhabitat availability and habitat heterogeneity. These changes can adapt to different ecological niches of aquatic organisms, increase biodiversity, and have a positive effect on the ecological restoration of inland freshwater marshes and wetlands.     

Temporal variation overshadows the response of leaf litter microbial communities to simulated global change

Bacteria and fungi drive the decomposition of dead plant biomass (litter), an important step in the terrestrial carbon cycle. Here we investigate the sensitivity of litter microbial communities to simulated global change (drought and nitrogen addition) in a California annual grassland. Using 16S and 28S rDNA amplicon pyrosequencing, we quantify the response of the bacterial and fungal communities to the treatments and compare these results to background, temporal (seasonal and interannual) variability of the communities. We found that the drought and nitrogen treatments both had significant effects on microbial community composition, explaining 2–6% of total compositional variation. However, microbial composition was even more strongly influenced by seasonal and annual variation (explaining 14–39%). The response of microbial composition to drought varied by season, while the effect of the nitrogen addition treatment was constant through time. These compositional responses were similar in magnitude to those seen in microbial enzyme activities and the surrounding plant community, but did not correspond to a consistent effect on leaf litter decomposition rate. Overall, these patterns indicate that, in this ecosystem, temporal variability in the composition of leaf litter microorganisms largely surpasses that expected in a short-term global change experiment. Thus, as for plant communities, future microbial communities will likely be determined by the interplay between rapid, local background variability and slower, global changes.     

Ecological and Evolutionary Effects of Stickleback on Community Structure

Species’ ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (Gasterosteus aculeatus). We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density) and evolutionary (phenotypic diversity and specialization) factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-a concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-a concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities.     

Different temporal trends in vascular plant and bryophyte communities along elevational gradients over four decades

Despite many studies showing biodiversity responses to warming, the generality of such responses across taxonomic groups remains unclear. Very few studies have tested for evidence of bryophyte community responses to warming, even though bryophytes are major contributors to diversity and functioning in many ecosystems. Here, we report an empirical study comparing long‐term change in bryophyte and vascular plant communities in two sites with contrasting long‐term warming trends, using “legacy” botanical records as a baseline for comparison with contemporary resurveys. We hypothesized that ecological changes would be greater in sites with a stronger warming trend and that vascular plant communities, with narrower climatic niches, would be more sensitive than bryophyte communities to climate warming. For each taxonomic group in each site, we quantified the magnitude of changes in species'' distributions along the elevation gradient, species richness, and community composition. We found contrasted temporal changes in bryophyte vs. vascular plant communities, which only partially supported the warming hypothesis. In the area with a stronger warming trend, we found a significant increase in local diversity and dissimilarity (β‐diversity) for vascular plants, but not for bryophytes. Presence–absence data did not provide sufficient power to detect elevational shifts in species distributions. The patterns observed for bryophytes are in accordance with recent literature showing that local diversity can remain unchanged despite strong changes in composition. Regardless of whether one taxon is systematically more or less sensitive to environmental change than another, our results suggest that vascular plants cannot be used as a surrogate for bryophytes in terms of predicting the nature and magnitude of responses to warming. Thus, to assess overall biodiversity responses to global change, abundance data from different taxonomic groups and different community properties need to be synthesized.     

Precipitation manipulation experiments--challenges and recommendations for the future

Climatic changes, including altered precipitation regimes, will affect key ecosystem processes, such as plant productivity and biodiversity for many terrestrial ecosystems. Past and ongoing precipitation experiments have been conducted to quantify these potential changes. An analysis of these experiments indicates that they have provided important information on how water regulates ecosystem processes. However, they do not adequately represent global biomes nor forecasted precipitation scenarios and their potential contribution to advance our understanding of ecosystem responses to precipitation changes is therefore limited, as is their potential value for the development and testing of ecosystem models. This highlights the need for new precipitation experiments in biomes and ambient climatic conditions hitherto poorly studied applying relevant complex scenarios including changes in precipitation frequency and amplitude, seasonality, extremity and interactions with other global change drivers. A systematic and holistic approach to investigate how soil and plant community characteristics change with altered precipitation regimes and the consequent effects on ecosystem processes and functioning within these experiments will greatly increase their value to the climate change and ecosystem research communities. Experiments should specifically test how changes in precipitation leading to exceedance of biological thresholds affect ecosystem resilience and acclimation.