Explore the vast range of titles available.

In contrast to pulses in resource availability following disturbance events, many of the most pressing global changes, such as elevated atmospheric carbon dioxide concentrations and nitrogen deposition, lead to chronic and often cumulative alterations in available resources. Therefore, predicting ecological responses to these chronic resource alterations will require the modification of existing disturbance-based frameworks. Here, we present a conceptual framework for assessing the nature and pace of ecological change under chronic resource alterations. The \"hierarchical-response framework\" (HRF) links well-documented, ecological mechanisms of change to provide a theoretical basis for testing hypotheses to explain the dynamics and differential sensitivity of ecosystems to chronic resource alterations. The HRF is based on a temporal hierarchy of mechanisms and responses beginning with individual (physiological/metabolic) responses, followed by species reordering within communities, and finally species loss and immigration. Each mechanism is hypothesized to differ in the magnitude and rate of its effects on ecosystem structure and function, with this variation depending on ecosystem attributes, such as longevity of dominant species, rates of biogeochemical cycling, levels of biodiversity, and trophic complexity. Overall, the HRF predicts nonlinear changes in ecosystem dynamics, with the expectation that interactions with natural disturbances and other global-change drivers will further alter the nature and pace of change. The HRF is explicitly comparative to better understand differential sensitivities of ecosystems, and it can be used to guide the design of coordinated, cross-site experiments to enable more robust forecasts of contemporary and future ecosystem dynamics.

Macroecology studies large-scale patterns aiming to identify the effects of general ecological processes. Although lakes (and ponds) are particularly suited for macroecological research due to their discrete nature and non geographically-structured variability, the development of this discipline in lentic habitats is comparatively much smaller than for terrestrial environments. This is despite the interest of limnologists for large-scale phenomena, which results in the high level of development of some disciplines such as predictive limnology. Here we discuss how current state-of-the-art in macroecology may benefit from research in lentic habitats at five topics. First, by including an island biogeography analytical framework to incorporate the effects of lake origin and history on lentic biodiversity. Second, by studying local and regional effects on the latitudinal gradients of species richness. Third, by considering lakes and ponds altogether for the study of beta diversity and metacommunity structure, which is already common ground in limnological research. Fourth, by relating species traits with ecosystem structure and functioning; here we consider in particular the potential effects of body size-determined dispersal and competitive exclusion processes on lake-wide trophic organization. And fifth, by incorporating current research in functional (i.e. trait) and phylogenetic diversity to the study of community structure. We finally conclude that lentic habitats can be particularly important for the development of the most functional aspects of macroecology, due to the relative ease of studying the different biotic and abiotic components of the system separately, compared to most terrestrial systems. This can allow teasing apart many of the confounding factors that are characteristic of macroecological research, thus helping the development of future theoretical syntheses.

The evaluation and prediction of ecological benefits are significant for regional resource development planning and path designing. This study established a novel ecological benefits evaluation system by integrating macro-ecosystem structure, Ecosystem service index (ESI), and ecological quality index (EQI). Based on this system, this study evaluated the spatiotemporal characteristics and changing trend of ecological benefits in Song-Liao River Basin (SRB) from 1990 to 2020. The results show that the macro-ecosystem structure in Song-Liao River Basin remains stable, and the ecosystem service and ecological quality generally show a trend of first decline and then increase. The average growth rates of ESI and EQI were 0.6% and 0.4%, respectively, during 1990–2020. The ecological benefits of natural areas with widely distributed forest areas are higher, while those of areas with frequent human activities are lower. The prediction model based on machine learning has achieved good modeling effect, which shows that the ecological benefits of SRB will be on the rise in the future. Based on the evaluation results, we suggest that more environmental protection policies on the basis of maintaining the existing development plan should be promoted to reduce the contradiction between human and nature in the development process. For the abundant natural forests in this area, reasonable forest management should be carried out to improve the carbon-fixation capacity of vegetation, and a Methodology for managing natural forests should be constructed to make full use of the existing carbon sinks. For the new afforestation project being promoted, carbon-sink afforestation projects of CCER (Chinese Certified Emission Reduction) should be promoted to realize the synergy between economic development and environmental protection.

Successful ecosystem-based management requires the selection and use of informative indicators of ecosystem status. We analyzed seven marine food web models to evaluate the performance of candidate indicators of ecosystem structure and function. The basic approach involved simulating fishing perturbations to each model, measuring the response of ecosystem attributes and candidate indicators to the perturbations, and testing the ability of the indicators to track changes in the values of the attributes. We focused on 22 ecosystem attributes, encompassing structural and functional properties that are relevant to a number of stakeholder groups but are typically difficult to measure directly (for example, food web structure, energy recycling). We tested for correlations between the attributes and 27 empirically tractable candidate indicators (for example, foraging guild biomasses, ratios of community-level groups) within each of the models and quantified consistency in indicator performance across the models. Our analysis suggests that no single indicator is sufficient to describe all of the ecosystem attributes, but at the same time highlights broad, catch-all indicators (for example, detritivores, jellyfish) and distinguishes the strongest attribute-indicator relationships. Ecosystem indicators consisting of lower-trophic level, higher-productivity functional groups tended to perform particularly well. We also identified indicators that showed strong or weak associations with different attributes, but together captured changes in nearly all of them. Examples of such complementary indicators include phytoplankton, zooplanktivorous fish, piscivorous fish, and trophic level of the catch. Quantitative approaches such as this one will enable managers to make informed decisions about ecosystem-scale monitoring in the oceans.

The global ocean has warmed substantially over the past century, with far-reaching implications for marine ecosystems1. Concurrent with long-term persistent warming, discrete periods of extreme regional ocean warming (marine heatwaves, MHWs) have increased in frequency2. Here we quantify trends and attributes of MHWs across all ocean basins and examine their biological impacts from species to ecosystems. Multiple regions in the Pacific, Atlantic and Indian Oceans are particularly vulnerable to MHW intensification, due to the co-existence of high levels of biodiversity, a prevalence of species found at their warm range edges or concurrent non-climatic human impacts. The physical attributes of prominent MHWs varied considerably, but all had deleterious impacts across a range of biological processes and taxa, including critical foundation species (corals, seagrasses and kelps). MHWs, which will probably intensify with anthropogenic climate change3, are rapidly emerging as forceful agents of disturbance with the capacity to restructure entire ecosystems and disrupt the provision of ecological goods and services in coming decades.Marine heatwaves are increasing in frequency, but they vary in their manifestation. All events impact ecosystem structure and functioning, with increased risk of negative impacts linked to greater biodiversity, number of species near their thermal limit and additional human impacts.

Biotic connectivity between ecosystems can provide major transport of organic matter and nutrients, influencing ecosystem structure and productivity 1 , yet the implications are poorly understood owing to human disruptions of natural flows 2 . When abundant, seabirds feeding in the open ocean transport large quantities of nutrients onto islands, enhancing the productivity of island fauna and flora 3 , 4 . Whether leaching of these nutrients back into the sea influences the productivity, structure and functioning of adjacent coral reef ecosystems is not known. Here we address this question using a rare natural experiment in the Chagos Archipelago, in which some islands are rat-infested and others are rat-free. We found that seabird densities and nitrogen deposition rates are 760 and 251 times higher, respectively, on islands where humans have not introduced rats. Consequently, rat-free islands had substantially higher nitrogen stable isotope (δ 15 N) values in soils and shrubs, reflecting pelagic nutrient sources. These higher values of δ 15 N were also apparent in macroalgae, filter-feeding sponges, turf algae and fish on adjacent coral reefs. Herbivorous damselfish on reefs adjacent to the rat-free islands grew faster, and fish communities had higher biomass across trophic feeding groups, with 48% greater overall biomass. Rates of two critical ecosystem functions, grazing and bioerosion, were 3.2 and 3.8 times higher, respectively, adjacent to rat-free islands. Collectively, these results reveal how rat introductions disrupt nutrient flows among pelagic, island and coral reef ecosystems. Thus, rat eradication on oceanic islands should be a high conservation priority as it is likely to benefit terrestrial ecosystems and enhance coral reef productivity and functioning by restoring seabird-derived nutrient subsidies from large areas of ocean. Productivity of coral reefs is enhanced near islands with no invasive rats, as populations of seabirds, which transfer nitrogen from deeper areas of ocean to the nearshore waters via their guano, are much larger than on rat-infested islands.

Global environmental changes have posed threats to ecosystems worldwide. Safeguarding terrestrial ecosystem health in particular is fundamental to achieving global sustainability targets, yet land degradation, carbon depletion and climate extremes continue to undermine resilience due to climate change and human activities. Therefore, Understanding human‐environment interactions is increasingly important for enhancing the resilience of terrestrial ecosystems under global change. The collection for this special issue addresses urgent challenges of land degradation, soil carbon loss, and ecosystem vulnerability by assembling eight regionally grounded studies from diverse landscapes of Asia. Collectively, these contributions reveal how land‐use transitions, restoration strategies and climate variability shape ecosystem health and carbon dynamics, while advancing methodological and governance frameworks that link science with policy. The collection offers critical insights and practical lessons for scholars and policy planners to sustainably manage land resources within the GeoHealth paradigm. Human activities and climate change are putting stress on forests, grasslands and farmlands. These pressures lead to land degradation, soil carbon loss and reduced ability of ecosystems to provide food, water, and clean air. This special issue brings together eight studies from Asia that examine how land use, restoration, and climate change affect soil carbon and ecosystem health. The findings show that solutions must be tailored to local conditions, for example, grazing strategies differ across grasslands, and restoration success depends on soil type. Urban expansion creates trade‐offs between food and water security, while forests in arid regions are especially at risk. The studies highlight that sustainable management needs both science‐based approaches and strong governance. Changes in land use patterns and restoration practices are central drivers of terrestrial ecosystem health and soil carbon dynamics Ecosystem responses are context‐dependent, requiring site‐specific and scale‐appropriate approaches and interventions Integrating biophysical, socio‐economic and institutional factors creates cross‐sector pathways for sustainable management

Understanding the relative importance of top-down and bottom-up regulation of ecosystem structure is a fundamental ecological question, with implications for fisheries and water-quality management. For the Laurentian Great Lakes, where, since the early 1970s, nutrient inputs have been reduced, whereas top-predator biomass has increased, we describe trends across multiple trophic levels and explore their underlying drivers. Our analyses revealed increasing water clarity and declines in phytoplankton, native invertebrates, and prey fish since 1998 in at least three of the five lakes. Evidence for bottom-up regulation was strongest in Lake Huron, although each lake provided support in at least one pair of trophic levels. Evidence for top-down regulation was rare. Although nonindigenous dreissenid mussels probably have large impacts on nutrient cycling and phytoplankton, their effects on higher trophic levels remain uncertain. We highlight gaps for which monitoring and knowledge should improve the understanding of food-web dynamics and facilitate the implementation of ecosystem-based management.

Until recently in Earth history, very large herbivores (mammoths, ground sloths, diprotodons, and many others) occurred in most of the World’s terrestrial ecosystems, but the majority have gone extinct as part of the late-Quaternary extinctions. How has this large-scale removal of large herbivores affected landscape structure and ecosystem functioning? In this review, we combine paleo-data with information from modern exclosure experiments to assess the impact of large herbivores (and their disappearance) on woody species, landscape structure, and ecosystem functions. In modern landscapes characterized by intense herbivory, woody plants can persist by defending themselves or by association with defended species, can persist by growing in places that are physically inaccessible to herbivores, or can persist where high predator activity limits foraging by herbivores. At the landscape scale, different herbivore densities and assemblages may result in dynamic gradients in woody cover. The late-Quaternary extinctions were natural experiments in large-herbivore removal; the paleoecological record shows evidence of widespread changes in community composition and ecosystem structure and function, consistent with modern exclosure experiments. We propose a conceptual framework that describes the impact of large herbivores on woody plant abundance mediated by herbivore diversity and density, predicting that herbivore suppression of woody plants is strongest where herbivore diversity is high. We conclude that the decline of large herbivores induces major alterations in landscape structure and ecosystem functions.

Flux across the carbon cycle is generally characterized by contributions from plants, microbes, and abiotic systems. Animals, however, move vast amounts of carbon, both through ecosystem webs and across the landscape. Schmitz et al. review the different contributions that animal populations make to carbon cycling and discuss approaches that allow for better monitoring of these contributions. Science , this issue p. eaar3213 Predicting and managing the global carbon cycle requires scientific understanding of ecosystem processes that control carbon uptake and storage. It is generally assumed that carbon cycling is sufficiently characterized in terms of uptake and exchange between ecosystem plant and soil pools and the atmosphere. We show that animals also play an important role by mediating carbon exchange between ecosystems and the atmosphere, at times turning ecosystem carbon sources into sinks, or vice versa. Animals also move across landscapes, creating a dynamism that shapes landscape-scale variation in carbon exchange and storage. Predicting and measuring carbon cycling under such dynamism is an important scientific challenge. We explain how to link analyses of spatial ecosystem functioning, animal movement, and remote sensing of animal habitats with carbon dynamics across landscapes.