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Climate change is altering naturally fluctuating environmental conditions in coastal and estuarine ecosystems across the globe. Departures from long-term averages and ranges of environmental variables are increasingly being observed as directional changes [e.g., rising sea levels, sea surface temperatures (SST)] and less predictable periodic cycles (e.g., Atlantic or Pacific decadal oscillations) and extremes (e.g., coastal flooding, marine heatwaves). Quantifying the short- and long-term impacts of climate change on tidal marsh seascape structure and function for nekton is a critical step toward fisheries conservation and management. The multiple stressor framework provides a promising approach for advancing integrative, cross-disciplinary research on tidal marshes and food web dynamics. It can be used to quantify climate change effects on and interactions between coastal oceans (e.g., SST, ocean currents, waves) and watersheds (e.g., precipitation, river flows), tidal marsh geomorphology (e.g., vegetation structure, elevation capital, sedimentation), and estuarine and coastal nekton (e.g., species distributions, life history adaptations, predator-prey dynamics). However, disentangling the cumulative impacts of multiple interacting stressors on tidal marshes, whether the effects are additive, synergistic, or antagonistic, and the time scales at which they occur, poses a significant research challenge. This perspective highlights the key physical and ecological processes affecting tidal marshes, with an emphasis on the trophic linkages between marsh production and estuarine and coastal nekton, recommended for consideration in future climate change studies. Such studies are urgently needed to understand climate change effects on tidal marshes now and into the future.

In a rapidly changing world, quantifying ecosystem resilience is an important challenge. Historically, resilience has been defined via models that do not take spatial effects into account. These systems can only adapt via uniform adjustments. In reality, however, the response is not necessarily uniform, and can lead to the formation of (self‐organised) spatial patterns – typically localised vegetation patches. Classical measures of resilience cannot capture the emerging dynamics in spatially self‐organised systems, including transitions between patterned states that have limited impact on ecosystem structure and productivity. We present a framework of interlinked phase portraits that appropriately quantifies the resilience of patterned states, which depends on the number of patches, the distances between them and environmental conditions. We show how classical resilience concepts fail to distinguish between small and large pattern transitions, and find that the variance in interpatch distances provides a suitable indicator for the type of imminent transition. Subsequently, we describe the dependency of ecosystem degradation based on the rate of climatic change: slow change leads to sporadic, large transitions, whereas fast change causes a rapid sequence of smaller transitions. Finally, we discuss how pre‐emptive removal of patches can minimise productivity losses during pattern transitions, constituting a viable conservation strategy., Classical measures of resilience cannot capture the emerging dynamics in spatially self‐organized, patterned systems, including transitions between patterned states that have limited impact on ecosystem structure and productivity. To complement these classical concepts, we present a framework of interlinked phase portraits that appropriately quantifies the resilience of patterned states, which depends on the number of patches, the distances between them and environmental conditions.

Anthropogenic environmental changes are altering ecological and evolutionary processes of ecosystems. The possibility that ecosystems can respond abruptly to gradual environmental change when critical thresholds are crossed (i.e. tipping points) and shift to an alternative stable state is a growing concern. Here I show that fast environmental change can trigger regime shifts before environmental stress exceeds a tipping point in evolving ecological systems. The difference in the time scales of coupled ecological and evolutionary processes makes ecosystems sensitive not only to the magnitude of environmental changes, but also to the rate at which changes are imposed. Fast evolutionary change mediated by high trait variation can reduce the sensitivity of ecosystems to the rate of environmental change and prevent the occurrence of rate-induced regime shifts. This suggests that management measures to prevent rate-induced regime shifts should focus on mitigating the effects of environmental change and protecting phenotypic diversity in ecosystems.

Desert steppe, a unique ecotone between steppe and desert in Eurasia, is considered highly vulnerable to global change. However, the long-term impact of warming and nitrogen deposition on plant biomass production and ecosystem carbon exchange in a desert steppe remains unknown. A 12-year field experiment was conducted in a Stipa breviflora desert steppe in northern China. A split-design was used, with warming simulated by infrared radiators as the primary factor and N addition as the secondary factor. Our long-term experiment shows that warming did not change net ecosystem exchange (NEE) or total aboveground biomass (TAB) due to contrasting effects on C4 (23.4% increase) and C3 (11.4% decrease) plant biomass. However, nitrogen addition increased TAB by 9.3% and NEE by 26.0% by increasing soil available N content. Thus, the studied desert steppe did not switch from a carbon sink to a carbon source in response to global change and positively responded to nitrogen deposition. Our study indicates that the desert steppe may be resilient to long-term warming by regulating plant species with contrasting photosynthetic types and that nitrogen deposition could increase plant growth and carbon sequestration, providing negative feedback on climate change.

Early-warning signals of a regime shift (EWS) indicate, for a wide range of systems, if a tipping-point is being approached. In ecology, EWS are well established from a theoretical perspective but are far from unequivocal when applied to field data. The gap between theory and application is caused by a set of limitations, like the lack of coherence between different EWS, data acquisition issues, and false results. Experiments assessing EWS may provide an empirical mechanistic understanding of why an EWS was observed (or failed to be observed), which often cannot be elucidated by simple computational modeling or pure environmental data. Here we focused on aquatic experiments to explore to what extent the existing EWS experiments can bridge the gap between the theory and real-world application. For that, we used the Thomson-ISI Web of Science© database to retrieve EWS experiments executed before early-2020, detailing their experimental designs and each EWS assessed. Success rates - correct anticipation of tipping points – were around 70% for the most used EWS (assessment of autocorrelation, variance, recovery, and shape of the distribution using abundance, Chlorophyll-a, Phycocyanin, and dissolved oxygen data). Yet, no EWS showed to be 100% reliable, and their use demands cautious interpretation. As a rule, we observed that experiments were not designed to tackle issues encountered in real-world situations. They lack a deep mechanistic understanding of why, when, and how an EWS was observed or not. When experiments did aim to assess issues encountered in the real world, the experimental designs were often of low ecological significance. We also investigated the relationship between sampling and the success rate of EWS, observing that the sampling regime might have to be tailor-made towards specific monitoring objectives. Moreover, experiments have taught us that the use of EWS can be more versatile than expected, going from monitoring the extinction of single populations to the anticipation of transient regime shifts. Most of the experiments presented here supported empirical proof of the existence of EWS in aquatic systems. Still, to bridge the gap between theory and application, experiments will have to move closer to real-world conditions and better support a mechanistic understanding of why EWS may succeed or fail to anticipate a regime shift. For that, we provide six elements to take into account when designing experiments that could enhance the capabilities of EWS to go beyond the stage of proof-of-concept.

The health of the world's oceans is intrinsically linked to the biodiversity of the ecosystems they sustain. The importance of protecting and maintaining ocean biodiversity has been affirmed through the setting of the UN Sustainable Development Goal 14 to conserve and sustainably use the ocean for society's continuing needs. The decade beginning 2021-2030 has additionally been declared as the UN Decade of Ocean Science for Sustainable Development. This program aims to maximize the benefits of ocean science to the management, conservation, and sustainable development of the marine environment by facilitating communication and cooperation at the science-policy interface. A central principle of the program is the conservation of species and ecosystem components of biodiversity. However, a significant omission from the draft version of the Decade of Ocean Science Implementation Plan is the acknowledgment of the importance of monitoring and maintaining genetic biodiversity within species. In this paper, we emphasize the importance of genetic diversity to adaptive capacity, evolutionary potential, community function, and resilience within populations, as well as highlighting some of the major threats to genetic diversity in the marine environment from direct human impacts and the effects of global climate change. We then highlight the significance of ocean genetic diversity to a diverse range of socioeconomic factors in the marine environment, including marine industries, welfare and leisure pursuits, coastal communities, and wider society. Genetic biodiversity in the ocean, and its monitoring and maintenance, is then discussed with respect to its integral role in the successful realization of the 2030 vision for the Decade of Ocean Science. Finally, we suggest how ocean genetic diversity might be better integrated into biodiversity management practices through the continued interaction between environmental managers and scientists, as well as through key leverage points in industry requirements for Blue Capital financing and social responsibility. info:eu-repo/semantics/publishedVersion

Megafauna shape ecosystems globally through trophic interactions, ecology of fear, and ecosystem engineering. Highly productive salt marshes at the interface of terrestrial and marine systems have the potential to support megafauna species, but a recent global meta-analysis of consumer-plant interactions in marshes found few studies investigated impacts of wild megafauna. We conducted a literature review to document the variety of megafauna in salt marshes and found that 34 species utilize salt marshes, including sharks, manatees, pinnipeds, crocodilians, sea otters, hippos, and large terrestrial animals, such as lions, bears and water buffalo. The use of salt marsh habitats by a variety of megafauna may have implications for both the conservation of these large consumers and for the resilience of coastal wetlands through stabilizing feedbacks on plant ecosystems. Future studies should quantify the occurrence and impacts of megafauna in salt marshes, and how their conservation can help restore these valuable ecosystems.

Quantitative approaches to measuring and assessing terrestrial ecosystem resilience, which expresses the ability of an ecosystem to recover from disturbances without shifting to an alternative state or losing function and services, is critical and essential to forecasting how terrestrial ecosystems will respond to global change. However, global and continuous terrestrial resilience measurement is fraught with difficulty, and the corresponding attribution of resilience dynamics is lacking in the literature. In this study, we assessed global terrestrial ecosystem resilience based on the long time-series GLASS LAI product and GIMMS AVHRR LAI 3g product, and validated the results using drought and fire events as the main disturbance indicators. We also analyzed the spatial and temporal variations of global terrestrial ecosystem resilience and attributed their dynamics to climate change and environmental factors. The results showed that arid and semiarid areas exhibited low resilience. We found that evergreen broadleaf forest exhibited the highest resilience (mean resilience value (from GLASS LAI): 0.6). On a global scale, the increase of mean annual precipitation had a positive impact on terrestrial resilience enhancement, while we found no consistent relationships between mean annual temperature and terrestrial resilience. For terrestrial resilience dynamics, we observed three dramatic raises of disturbance frequency in 1989, 1995, and 2001, respectively, along with three significant drops in resilience correspondingly. Our study mapped continuous spatiotemporal variation and captured interannual variations in terrestrial ecosystem resilience. This study demonstrates that remote sensing data are effective for monitoring terrestrial resilience for global ecosystem assessment.

Deltas are home to a large and growing proportion of the world's population, often living in conditions of extreme poverty. Deltaic ecosystems are ecologically significant as they support high biodiversity and a variety of fisheries, however these coastal environments are extremely vulnerable to climate change. The Ganges-Brahmaputra-Meghna (Bangladesh/India), the Mahanadi (India), and the Volta (Ghana) are among the most important and populous delta regions in the world and they are all considered at risk of food insecurity and climate change. The fisheries sector is vital for populations that live in the three deltas, as a source of animal protein (in Bangladesh and Ghana around 50 60% of animal protein is supplied by fish while in India this is about 12%) through subsistence fishing, as a source of employment and for the wider economy. The aquaculture sector shows a rapid growth in Bangladesh and India while in Ghana this is just starting to expand. The main exported species differ across countries with Ghana and India dominated by marine fish species, whereas Bangladesh exports shrimps and prawns. Fisheries play a more important part in the economy of Bangladesh and Ghana than for India, both men and women work in fisheries, with a higher proportion of women in the Volta then in the Asian deltas. Economic and integrated modelling using future scenarios suggest that changes in temperature and primary production could reduce fish productivity and fisheries income especially in the Volta and Bangladesh deltas, however these losses could be mitigated by reducing overfishing and improving management. The analysis provided in this paper highlights the importance of applying plans for fisheries management at regional level. Minimizing the impacts of climate change while increasing marine ecosystems resilience must be a priority for scientists and governments before these have dramatic impacts on millions of people's lives. © 2018 Elsevier B.V. Jose A. Fernandes received further funding through the Gipuzkoa Talent Fellowships programme, by the Gipuzkoa Provincial Council, Spain.

The massive forests of central Amazonia are often considered relatively resilient against climatic variation, but this view is challenged by the wildfires invoked by recent droughts. The impact of such fires that spread from pervasive sources of ignition may reveal where forests are less likely to persist in a drier future. Here we combine field observations with remotely sensed information for the whole Amazon to show that the annually inundated lowland forests that run through the heart of the system may be trapped relatively easily into a fire-dominated savanna state. This lower forest resilience on floodplains is suggested by patterns of tree cover distribution across the basin, and supported by our field and remote sensing studies showing that floodplain fires have a stronger and longer-lasting impact on forest structure as well as soil fertility. Although floodplains cover only 14% of the Amazon basin, their fires can have substantial cascading effects because forests and peatlands may release large amounts of carbon, and wildfires can spread to adjacent uplands. Floodplains are thus an Achilles' heel of the Amazon system when it comes to the risk of large-scale climate-driven transitions.

International audience; Potential time lags between human-mediated disturbances and the subsequent responses of ecosystems are critical for planning and implementing conservation and restoration actions. In this context, decoupling between the temporal trajectories of ecosystems structure and functions is particularly critical. Here, we stand out the need to differentiate the temporal trajectories of ecosystem structure and functions to be considered in ecological restoration programs. In cases when ecosystem functions persist after the degradation of the ecosystem structure, and when functions do not recover at the same rate as structure, some kind of ecosystem functioning credits or debts can occur. In other situations, an ongoing loss of the ecosystem function can occur even in the absence of further disturbance. Ecosystem restoration outcomes could be optimized in regions with ecosystem functioning credit, since mitigating the decline in functioning will be more efficient than recovering functions in highly degraded conditions. Ecological restoration programs should not only focus on structurederived indicators but they should also consider the dynamics of ecosystem functions to guide land-planning decisionmaking.

Study region: This study was developed in two paired catchments under a tropical dry climate with a tropical dry forest landcover subject to vegetation management in the Brazilian northeastern region. Water input is mostly from rainfall, concentrated in three to four months of the year and with a potential evaporation that is over twice the amount of rainfall that characterizes its hydric deficit. Study focus: Interactions between hydrological functions, services and human actions to minimize environmental impacts, improve the availability of water of good quality and decrease degradation of the ecosystems; land use management effect on systems resilience, impact on surface runoff, soil loss, herbaceous and radicular biomass production, soil humidity and total organic carbon under altered vegetation cover. New hydrological insights for the region: Strategies to improve ecosystem services should rely on adequate management of vegetation to reduce surface flow. This reduction contributes to higher soil moisture contents, less intense erosive processes and resulting higher stocked soil carbon. The many techniques that improve resilience and ecosystem services in tropical dry forests lack an integrated view on how ecohydrological processes may be managed to favor the system. Vegetation thinning promotes underbrush development that dissipates rainfall and surface flow kinetic energy, increasing soil moisture content and carbon fixation and reducing soil loss. Keywords: semi-arid hydrology, tropical dry forest, ecosystem services, ecosystem resilience, ecohydrology, hydrologic processes

Ecosystem water use efficiency (WUE describes carbon-water flux coupling in terrestrial ecosystems. Understanding response and resilience of WUE to drought are essential for sustainable water resource and ecosystem management under increasing drought risks over China due to climate warming. Here we analyzed the response of ecosystem WUE to drought (spatiotemporal variability and resilience) over China during 1982&ndash, 2015 based on an evapotranspiration (ET) dataset based on the model tree ensemble (MTE) algorithm using flux-tower ET measurements and satellite-retrieved GPP data. The results showed that the multiyear average WUE was 1.55 g C kg&minus, 1 H2O over China. WUE increased in 77.1% of Chinese territory during the past 34 years. During drought periods, the ecosystem WUE increased mainly in the northeast of Inner Mongolia, Northeast China and some regions in southern China with abundant forests but decreased in northwestern and central China. An apparent lagging effect of drought on ecosystem WUE was observed in the east of Inner Mongolia and Northeast China, the west and east regions of North China and the central part of Tibetan Plateau. Some ecosystems (e.g., deciduous needle-leaf forests, deciduous broadleaf forests, evergreen broadleaf forests and evergreen needle-leaf forests) in Central China, Northeast and Southwest China exhibited relatively greater resilience to drought than others by improving their WUE. Our findings would provide useful information for Chinese government to adopt a reasonable approach for maintaining the structure and functions of ecosystems under drought disturbance in future.

Aim: To investigate if connectivity and zebra mussel (Dreissena polymorpha) occurrence can mitigate effects of eutrophication in a lowland lake landscape. Location: Upper Lough Erne, Northern Ireland, UK. Methods: Data on environment, macrophytes and invertebrates were assembled for three basins of a large central lake and its satellite floodplain lakes via field surveys and palaeolimnological analyses. Space–time interaction analyses of palaeoecological data were compared pre-1950 and post-1950. Multivariate analyses examined how connectivity, environment and zebra mussels influenced contemporary lake communities, and explain their divergence from historical communities in the past. Results: Pre-1950, we found high community variation across sites and low within-lake variation in macrophytes, but progressive eutrophication accentuated within-lake community variation after 1950. Partitioning analysis showed larger effects of connectivity than nutrient enrichment on contemporary macrophyte composition, while local effects structured invertebrate communities. Three clusters of lakes were revealed according to variation in macrophyte composition, isolation from the central lake and nutrient enrichment: Group 1– the central lake and six nearby lakes were meso-eutrophic (TP = 66.7 ± 47.6 μg/L; TN = 0.79 ± 0.41 mg/L) and had the highest zebra mussel abundances and organismal biodiversity; Group 2– Eight eutrophic (TP = 112±36.6 μg/L; TN = 1.25 ± 0.5 mg/L) and connected lakes; Group 3– Seven isolated and hypertrophic (TP = 163.2 ± 101.5 μg/L; TN = 1.55 ± 0.3 mg/L) lakes. Pre-1950 palaeolimnological data for macrophytes and invertebrates for 5 lakes and a basin in the central lake most resembled extant lake communities of Group 1. However, palaeo-records revealed that macrophytes and invertebrates subsequently converged towards those of Groups 2 and 3. Main conclusions: Our study reveals that the central “mother” lake acts as a hub for preserving biodiversity via shared hydrological connectivity with satellite lakes and high zebra mussel abundances. These may buffer the impoverishing effects of eutrophication and sustain unexpectedly high biodiversity in the short term. Such protective buffering, however, cannot be relied upon indefinitely to conserve biodiversity.

This paper addresses the challenge of appropriate governance of complexity and diversity in the Dutch national park of Alde Feanen. The issue is how to enhance ecosystem resilience. Our focus relates to a navigable waterway within the park that affects the natural values of the area. The governance assessment tool is used to assess the governance context of the waterway and ecosystem resilience in the area. The study shows that a lack of a long-term integrated vision makes the governance context less supportive. Such a vision could maximize the focus on the resilience of the park's nature and motivate actors to work towards a common future for a concerned area. However, institutional complexity, combined with institutional inertia, is revealed as a hindrance to the quality of governance and shapes a weak ability to adapt the current situation to move towards resilience.

Understanding the response of vegetation and ecosystem resilience to climate variability and drought conditions is essential for ecosystem planning and management. In this study, we assessed the vegetation changes and ecosystem resilience in the Horn of Africa (HOA) since 2000 and detected their drivers based mainly on analysis of the Moderate Resolution Imaging Spectroradiometer (MODIS) products. We found that the annual and seasonal trends of NDVI (Normalized Difference Vegetation Index) generally increased during the last two decades over the Horn of Africa particularly in western parts of Ethiopia and Kenya. The weakest annual and seasonal NDVI trends were observed over the grassland cover and tropical arid agroecological zones. The NDVI variation negatively correlated with Land Surface Temperature (LST) and positively correlated with precipitation at a significant level (p < 0.05) account for 683,197 km2 and 533,385 km2 area, respectively. The ecosystem Water Use Efficiency (eWUE) showed overall increasing trends with larger values for the grassland biome. The precipitation had the most significant effect on eWUE variation compared to LST and annual SPEI (Standardized Evapotranspiration Index). There were about 54.9% of HOA resilient to drought disturbance, whereas 32.6% was completely not-resilient. The ecosystems in the humid agroecological zones, the cropland, and wetland were slightly not-resilient to severe drought conditions in the region. This study provides useful information for policy makers regarding ecosystem and dryland management in the context of climate change at both national and regional levels.

Land-use change is one of the primary drivers of species loss, yet little is known about its effect on other components of biodiversity that may be at risk. Here, we ask whether, and to what extent, landscape simplification, measured as the percentage of arable land in the landscape, disrupts the functional and phylogenetic association between primary producers and consumers. Across seven European regions, we inferred the potential associations (functional and phylogenetic) between host plants and butterflies in 561 semi-natural grasslands. Local plant diversity showed a strong bottom-up effect on butterfly diversity in the most complex landscapes, but this effect disappeared in simple landscapes. The functional associations between plant and butterflies are, therefore, the results of processes that act not only locally but are also dependent on the surrounding landscape context. Similarly, landscape simplification reduced the phylogenetic congruence among host plants and butterflies indicating that closely related butterflies become more generalist in the resources used. These processes occurred without any detectable change in species richness of plants or butterflies along the gradient of arable land. The structural properties of ecosystems are experiencing substantial erosion, with potentially pervasive effects on ecosystem functions and future evolutionary trajectories. Loss of interacting species might trigger cascading extinction events and reduce the stability of trophic interactions, as well as influence the longer-term resilience of ecosystem functions. This underscores a growing realization that species richness is a crude and insensitive metric and that both functional and phylogenetic associations, measured across multiple trophic levels, are likely to provide additional and deeper insights into the resilience of ecosystems, and the functions they provide.

ISI Document Delivery No.: HK8WZ Times Cited: 1 Cited Reference Count: 76 Thomas, Zahra Rousseau-Gueutin, Pauline Abbott, Benjamin W. Kolbe, Tamara Le Lay, Hugo Marcais, Jean Rouault, Francois Petton, Christophe Pichelin, Pascal Le Hennaff, Genevieve Squividant, Herve Labasque, Thierry de Dreuzy, Jean-Raynald Aquilina, Luc Baudry, Jacques Pinay, Gilles French National Research Agency (ANR) [ANR-08-STRA-01]; European Union Inter-national Training Network "Ecohydrological interfaces as critical hotspots for transformations of ecosystem exchange fluxes and biogeochemical cycling" [607150]; French EC2CO grant "Caracterisation hydrologique et biogeochimique de la denitrification dans les paysages"; LTSER "Zone Atelier Armorique" This research was supported in part by the French National Research Agency (ANR; Project ANR-08-STRA-01) and the European Union Inter-national Training Network "Ecohydrological interfaces as critical hotspots for transformations of ecosystem exchange fluxes and biogeochemical cycling" (ITN-INTERFACES - FP7-PEOPLE-2013-No. 607150). This research was also supported by the French EC2CO grant "Caracterisation hydrologique et biogeochimique de la denitrification dans les paysages." The study was supported by the LTSER "Zone Atelier Armorique." We thank all the farmers of the ZAAr who kindly accepted the installation of the experiments in their fields. We also thank all the staff of the ILSTER Zone Atelier Armorique, especially the technicians of OSUR-INRA-AGROCAMPUS who helped in sampling and laboratory analysis. 1 0 Springer heidelberg Heidelberg 1436-378x Si; International audience; Over the last half century, humans have become the dominant force driving many of Earth’s cycles. Intensive agriculture has simultaneously increased nutrient loading of pastoral landscapes and decreased the capacity of these ecosystems to retain or remove excess nutrients. Widespread degradation of terrestrial and aquatic ecosystems has triggered the establishment of ecological observatories, including the Zone Atelier Armorique (ZAAr) in western France, a part of the International Long-Term Socio-Ecological Research (LTSER) network. The ZAAr includes a patchwork of land covers and uses, including old-growth forests, intensively cultivated row crops, and ancient bocage fields surrounded by hedgerows. In addition to traditional ecological research at ZAAr, the last 8 years have seen the development of multiproxy and multiscale approaches to address surface and groundwater quality. Here, we present a comprehensive analysis of this 8-year dataset, including vegetation, soil water storage, and stream and groundwater chemistry. We observed contrasting responses of different catchment components to climate forcing and direct disturbance. Our results highlight a clear relationship between land use and surface water quality, while groundwater quality appeared largely unrelated to land use, suggesting strong differences in aquifer nitrogen removal rates. There were large differences in nutrient fluxes among dry and wet years, with multiyear memory effects apparent for some parameters. Given such complex interactions, including emergent dynamics and decadal to centennial time lags, we conclude that multidimensional observations such as those supported by the ZAAr and other LTSER sites, are critical to understanding ecohydrological systems in the Anthropocene.

International audience; To understand long-term ecosystem dynamics, several concepts have been recently proposed that consider ‘basins of attraction’ to express resilience and ‘tipping points’ that express sharp change in an ecosystem's behaviour. However, these temporal features remain difficult to identify and quantify because current models usually focus only on a part of the whole ecosystem behaviour, whereas a holistic approach should be preferred. We propose an original family of models based on discrete systems and designed to comprehensively characterize ecosystem dynamics holistically and over the long term. We developed a qualitative model based on Petri nets, made up of a relational graph (interaction network) that was then rigorously handled using transition rules. Unlike traditional modelling and graph theory approaches, transition rules can strongly modify the graph structure (i.e. a dynamic topology occurs). We examined the value of Petri nets when applied to the simple ecosystem of a termite colony. A termite colony comprises of abiotic and biotic components and processes that we explored along all of their possible trajectories. Several temporal features, such as basins of attraction (i.e. strongly connected states), tipping points (critical transitions along trajectories) and various kinds of collapses (functioning systems whose structures were nevertheless fixed), were easily detected and quantified. We propose that Petri nets developed for more complex ecosystems will provide original insights into their holistic behaviour.

Prediction of ecosystem response to global environmental change is a pressing scientific challenge of major societal relevance. Many ecosystems display nonlinear responses to environmental change, and may even undergo practically irreversible ‘regime shifts’ that initiate ecosystem collapse. Recently, early warning signals based on spatiotemporal metrics have been proposed for the identification of impending regime shifts. The rapidly increasing availability of remotely sensed data provides excellent opportunities to apply such model‐based spatial early warning signals in the real world, to assess ecosystem resilience and identify impending regime shifts induced by global change. Such information would allow land‐managers and policy makers to interfere and avoid catastrophic shifts, but also to induce regime shifts that move ecosystems to a desired state. Here, we show that the application of spatial early warning signals in real‐world landscapes presents unique and unexpected challenges, and may result in misleading conclusions when employed without careful consideration of the spatial data and processes at hand. We identify key practical and theoretical issues and provide guidelines for applying spatial early warning signals in heterogeneous, real‐world landscapes based on literature review and examples from real‐world data. Major identified issues include (1) spatial heterogeneity in real‐world landscapes may enhance reversibility of regime shifts and boost landscape‐level resilience to environmental change (2) ecosystem states are often difficult to define, while these definitions have great impact on spatial early warning signals and (3) spatial environmental variability and socio‐economic factors may affect spatial patterns, spatial early warning signals and associated regime shift predictions. We propose a novel framework, shifting from an ecosystem perspective towards a landscape approach. The framework can be used to identify conditions under which resilience assessment with spatial remotely sensed data may be successful, to support well‐informed application of spatial early warning signals, and to improve predictions of ecosystem responses to global environmental change., Ongoing global change steadily increases pressure on ecosystems, to the point where a small additional change may cause a sudden ecosystem state shift and drastically modify ecosystem functioning. Predicting such generally undesired ‘regime shifts’ is crucial for timely management intervention. A promising prediction method is the translation of spatial vegetation patterns observed with, for example, satellite imagery into ecosystem resilience indicators. While these spatial indicators perform well in theory, we show how application to real‐world landscapes presents unexpected challenges and may even lead to misleading conclusions. Our study identifies the conditions for successful application of spatial indicators to real‐world landscapes.

Species distribution is strongly driven by local and global gradients in water availability but the underlying mechanisms are not clear. Vulnerability to xylem embolism (P 50 ) is a key trait that indicates how species cope with drought and might explain plant distribution patterns across environmental gradients. Here we address its role on species sorting along a hydro-topographical gradient in a central Amazonian rainforest and examine its variance at the community scale. We measured P 50 for 28 tree species, soil properties and estimated the hydrological niche of each species using an indicator of distance to the water table (HAND). We found a large hydraulic diversity, covering as much as 44% of the global angiosperm variation in P 50 . We show that P 50 : contributes to species segregation across a hydro-topographic gradient in the Amazon, and thus to species coexistence; is the result of repeated evolutionary adaptation within closely related taxa; is associated with species tolerance to P-poor soils, suggesting the evolution of a stress-tolerance syndrome to nutrients and drought; and is higher for trees in the valleys than uplands. The large observed hydraulic diversity and its association with topography has important implications for modelling and predicting forest and species resilience to climate change. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust

Ecological processes may exhibit memory to past disturbances affecting the resilience of ecosystems to future disturbance. Understanding the role of ecological memory in shaping ecosystem responses to disturbance under global change is a critical step toward developing effective adaptive management strategies to maintain ecosystem function and biodiversity. We developed EcoMem, an R package for quantifying ecological memory functions using common environmental time series data (continuous, count, proportional) applying a Bayesian hierarchical framework. The package estimates memory functions for continuous and binary (e.g., disturbance chronology) variables making no a priori assumption on the form of the functions. EcoMem allows users to quantify ecological memory for a wide range of ecosystem processes and responses. The utility of the package to advance understanding of the memory of ecosystems to environmental drivers is demonstrated using a simulated dataset and a case study assessing the memory of boreal tree growth to insect defoliation., Comment: 11 pages, 3 figures, 2 appendices

[Departement_IRSTEA]Ecotechnologies [ADD1_IRSTEA]Dynamique et fonctionnement des écosystèmes; International audience; The most common approach to mitigation of lake eutrophication is reduction of phosphorus emissions, in particular by changing farm management. This reduction can be combined with landscaping retention structures upstream of the lake, the analyses of which the paper is based on. The management of these structures currently focuses on maximising the quantity of phosphorus trapped, regardless of lake dynamics. This paper adapts a dynamical model of lake phosphorus to examine the effects of these phosphorus retention structures. We highlight two effects: first, a structure that traps some of the phosphorus load before it reaches the lake reduces the amount of phosphorus in lake water. Second, some retention structures slow down lake phosphorus dynamics in a way that may perversely slow lake restoration. We propose a cleaning strategy that maximises the chances of restoring a lake to an oligotrophic condition. We demonstrate our model with a real-world case study.

The concept of "reciprocity" between humans and other biota arises from the creation belief of the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). The concept acknowledges a moral and practical obligation for humans and biota to care for and sustain one another, and arises from human gratitude and reverence for the contributions and sacrifices made by other biota to sustain human kind. Reciprocity has become a powerful organizing principle for the CTUIR Department of Natural Resources, fostering continuity across the actions and policies of environmental management programs at the CTUIR. Moreover, reciprocity is the foundation of the CTUIR "First Foods" management approach. We describe the cultural significance of First Foods, the First Foods management approach, a resulting management vision for resilient and functional river ecosystems, and subsequent shifts in management goals and planning among tribal environmental staff during the first decade of managing for First Foods. In presenting this management approach, we highlight how reciprocity has helped align human values and management goals with ecosystem resilience, yielding management decisions that benefit individuals and communities, indigenous and nonindigenous, as well as human and nonhuman. We further describe the broader applicability of reciprocity-based approaches to natural resource management.

Environmental management strategies aim to protect or repair ecological assets (ecosystems, species) so that their ecological and social values can be preserved. However, creating an effective strategy is difficult because multiple government departments are involved and because water and land use legislation and policy instruments are often fragmented. A key obstacle that is often overlooked is the spatial mismatch between ecological processes and institutional organisation (i.e., legislative framework and government departments). Successful management depends on the ability to cultivate resilient ecosystems through institutional reforms that take into account the complexity of ecosystems while supporting cross-sectoral and scale-dependent decision-making within the science–policy interface. Here, we use a case study approach to illustrate how collective strategic decisions can be made to manage a valued ecosystem situated within an urban matrix. We used a three-step framework to guide our approach and commenced by identifying a range of adaptation measures (i.e., management interventions) and the actors responsible. For each adaptation measure, we then investigated (i) mismatches among ecosystem and institution scales and levels; (ii) institutional barriers; and (iii) the role of actors in decision making. We use this information to identify ‘decision pathways’: i.e., a flexible decision-making platform that assists stakeholders to make strategic short- and long-term decisions. Key insights included the discussion of policy and practical experiences for ecosystem management at different levels and the necessary conditions to provide better alignment between jurisdictional an ecosystem scale to guide decision makers accordingly. We detail the institutional and jurisdictional changes that must be implemented across all levels of governance to protect and support the resilience of environmental assets. ‘Short-term’ decision pathways were preferred among actors and cross-level cooperation at jurisdictional level provided an adequate fit with the ecosystem scale. ‘Long-term’ decisions require substantial change of the institutional framework to enable the implementation of adaptive management. Although challenges at institutional and jurisdictional scales remain, decision pathways promote adaptive ecosystem management through a better fit of jurisdictional and institutional roles/policy and ecosystem-scale processes.

International audience; Ecosystem resilience is the capacity of ecosystems to tolerate disorders without collapsing into different circumstances qualitatively controlled by a different set of processes. A robust ecosystem is one that can withstand shocks and rebuild itself when necessary. This study aims to identify the value of use-based economy and non-use value of current economy; calculating the total economic value of mangrove resources; and provide suggestions and recommendations based on observations in Timbulsloko, Sayung, Demak. The method used is economic valuation with total economic value technique. The sampling technique used non-probability and purposive sampling method. The results showed that the direct use value of mangroves was utilized by fisherman, fish pond farmers, branjang catchers, oystercatchers, trap makers, shop owner, grilled fish makers and shrimp chip makers. Indirect use value was derived from function as the breakwater, beach belt and hybrid engineering. Existing value was not less than 10 % of the direct use value. The total economic value was Rp. 6,361,430,639/year or about Rp. 202,335,580.1/ha/year. It is need to improve the community awareness to mangrove ecosystem and to the role of breakwater in order to reduce risk disaster and to develop an ecotourism in the area

International audience; Spatial self-organization of dryland vegetation constitutes one of the most promising indicators for an ecosystem’s proximity to desertification. This insight is based on studies of reaction–diffusion models that reproduce visual characteristics of vegetation patterns observed on aerial photographs. However, until now, the development of reliable early warning systems has been hampered by the lack of more in-depth comparisons between model predictions and real ecosystem patterns. In this paper, we combined topographical data, (remotely sensed) optical data, and in situ biomass measurements from two sites in Somalia to generate a multilevel description of dryland vegetation patterns. We performed an in-depth comparison between these observed vegetation pattern characteristics and predictions made by the extended-Klausmeier model for dryland vegetation patterning. Consistent with model predictions, we found that for a given topography, there is multistability of ecosystem states with different pattern wavenumbers. Furthermore, observations corroborated model predictions regarding the relationships between pattern wavenumber, total biomass, and maximum biomass. In contrast, model predictions regarding the role of slope angles were not corroborated by the empirical data, suggesting that inclusion of small-scale topographical heterogeneity is a promising avenue for future model development. Our findings suggest that patterned dryland ecosystems may be more resilient to environmental change than previously anticipated, but this enhanced resilience crucially depends on the adaptive capacity of vegetation patterns.

Copyright by the Ecological Society of America, Increasing frequency of extreme climatic events can disrupt ecosystem processes and destabilize ecosystem functioning. Biodiversity may dampen these negative effects of environmental perturbations to provide greater ecosystem stability. We assessed the effects of plant diversity on the resistance, recovery and stability of experimental grassland ecosystems in response to recurring summer drought over 7 yr. Plant biomass production was reduced during the summer drought treatment compared with control plots. However, the negative effect of drought was relatively less pronounced at high than at low plant diversity, demonstrating that biodiversity increased ecosystem resistance to environmental perturbation. Furthermore, more diverse plant communities compensated for the reduced productivity during drought by increasing spring productivity compared to control plots. The drought-induced compensatory recovery led to increased short-term variations in productivity across growing seasons in more diverse communities that stabilized the longer-term productivity across years. Our findings show that short-term variation between seasons in the face of environmental perturbation can lead to longer-term stability of annual productivity in diverse ecosystems compared to less diverse ecosystems., German Research Foundation. Grant Numbers: FZT 118, FOR 456, FOR 1451 Stiefel-Zangger Fund SNF Mobility Grant. Grant Number: P2ZHP3_161986 German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig

RESUMEN: Se presenta un modelo ecohidrológico simplificado para evaluar cuantitativamente la resiliencia y estabilidad de los ecosistemas durante largos períodos. El modelo acopla el balance hidrológico de humedad del suelo con un conjunto de dinámicas espaciotemporales de sistemas y algoritmos basados en agentes para representar las interacciones entre varias poblaciones de plantas en un área de grilla bajo diferentes restricciones de agua, suelo y temperatura. Las poblaciones de plantas se caracterizan por reglas alométricas (por ejemplo, leyes de potencia para tiempos generacionales y reproductivos; aproximaciones lineales para ganancias de agua y temperatura; pérdidas y valores óptimos; y un conjunto de reglas de interacción intra e interespecíficas basadas en respuestas de competencia altas, óptimas y bajas entre las poblaciones), que representan diferentes fenotipos de plantas. Los trastornos se determinan por una remoción de las poblaciones en un área dentro del dominio del modelo. La resistencia y la estabilidad se calculan con índices simples para determinar la capacidad del ecosistema para recuperarse de una perturbación. Los índices evaluados en cada población y sobre la estructura de todo el ecosistema muestran cómo las poblaciones responden de manera diferente a los disturbios, siguiendo patrones similares a los esperados en la naturaleza. El modelo puede representar la sucesión espacial y temporal del ecosistema después de ser perturbado, lo que sugiere que las diferencias en las características fenotípicas de las poblaciones de plantas pueden ser ventajosas o desventajosas para la recuperación del ecosistema. Palabras clave: Resiliencia de ecosistemas; estabilidad de ecosistemas; ecohidrología; modelos basados en agentes; dinámica de sistemas. ABSTRACT: We introduce a simplified ecohydrological model to quantitatively assess the resiliency and stability of ecosystems over long periods. The model couples a hydrological soil moisture balance with a set of spatiotemporal systems dynamics and agent-based algorithms to represent the interactions among several plant populations in a gridded area under different water, soil and temperature constraints. We characterize the plant populations by allometric rules (i.e., power laws for generational and reproductive times; linear approximations for water and temperature gains, losses and optimal values; and a set of intra and interspecific interaction rules based on high, optimal and low competition responses among the populations), that represent different plant phenotypes. We define the disturbances by a clearance of populations in an area within the model’s domain and calculate the resiliency and stability with simple indices to determine the ability of the ecosystem to recover from a disturbance. The indices evaluated on each population and over the structure of the entire ecosystem show how the populations respond differently to disturbances, following patterns similar to those expected in nature. The model can represent the spatial and temporal succession of the ecosystem after being disturbed, suggesting how the differences in the phenotypical characteristics of plant populations can be advantageous or disadvantageous for the ecosystem recovery. keywords: Ecosystem resilience; ecosystem stability; ecohydrology; agent-based models; system dynamics.

The occurrence of multiple disturbances can jointly affect the recovery capacity of ecosystems, potentially leading to changes in vegetation dynamics or loss of resilience. The effects of interacting disturbances on ecosystems are, however, not well understood. We use a model system based on Mediterranean‐type ecosystems (MTE s) to examine how the interplay between vegetation regeneration traits and compound, stochastic disturbances modulate ecosystem dynamics. We developed a state‐and‐transition simulation model including two tree species with contrasting regeneration strategies (seeder vs. resprouter) and a shrubland formation. We aim to assess potential compositional switches under contrasted scenarios of compound fire–drought regimes, and to characterize the cumulative effects of fire–drought (synergism vs. antagonism) relative to the effects of individual disturbance regimes. Our simulation results indicate that interaction between moderate fire and sporadic drought recurrence—as opposed to chronic dryness—can act as a strong mechanism generating highly heterogeneous landscapes in which different regeneration types coexist, as observed in MTE s. Resprouters dominated under individual, moderate disturbance regimes of fire or drought, whereas the interaction of the two disturbances promoted the long‐term coexistence of both tree regeneration strategies. However, shrubland expansion and persistence at the expanse of forests was favored by increases in drought recurrence and associated fire–drought interactions, highlighting the potential for important vegetation changes in MTE s under climate change. Overall, the cumulative effects of fire and drought can lead to distinct landscape configurations under moderate disturbance regimes that are otherwise only attained under high frequency of individual disturbances. At the ecosystem level, however, we suggest that disturbance‐induced vegetation dynamics can modify vegetation sensitivity and resilience to further disturbances precluding the prevalence of synergistic effects of the two disturbances. Enric Batllori thanks the support of a Marie Curie International Incoming Fellowship (PIFF‐GA‐2013‐625547) and Miquel De Cáceres the support of a Spanish Ramon y Cajal Fellowship. Lluís Brotons and Francisco Lloret thank the support of the research group 2014 SGR 00453 and the projects FORESTCAST, NEWFORESTS, INFORMED, SECADIN, and BIOCLIM.

Quantifying environmental controls on vegetation is critical to predict the net effect of climate change on global ecosystems and the subsequent feedback on climate. Following a non-linear Granger causality framework based on a random forest predictive model, we exploit the current wealth of multi-decadal satellite data records to uncover the main drivers of monthly vegetation variability at the global scale. Results indicate that water availability is the most dominant factor driving vegetation globally: about 61% of the vegetated surface was primarily water-limited during 1981-2010. This included semiarid climates but also transitional ecoregions. Intraannually, temperature controls Northern Hemisphere deciduous forests during the growing season, while antecedent precipitation largely dominates vegetation dynamics during the senescence period. The uncovered dependency of global vegetation on water availability is substantially larger than previously reported. This is owed to the ability of the framework to (1) disentangle the co-linearities between radiation/temperature and precipitation, and (2) quantify non-linear impacts of climate on vegetation. Our results reveal a prolonged effect of precipitation anomalies in dry regions: due to the long memory of soil moisture and the cumulative, nonlinear, response of vegetation, water-limited regions show sensitivity to the values of precipitation occurring three months earlier. Meanwhile, the impacts of temperature and radiation anomalies are more immediate and dissipate shortly, pointing to a higher resilience of vegetation to these anomalies. Despite being infrequent by definition, hydro-climatic extremes are responsible for up to 10% of the vegetation variability during the 1981-2010 period in certain areas, particularly in water-limited ecosystems. Our approach is a first step towards a quantitative comparison of the resistance and resilience signature of different ecosystems, and can be used to benchmark Earth system models in their representations of past vegetation sensitivity to changes in climate.

Reconciling food security, economic development and biodiversity conservation is a key challenge, especially in the face of the demographic transition characterizing many countries in the world. Fisheries and marine ecosystems constitute a difficult application of this bio-economic challenge. Many experts and scientists advocate an ecosystem approach to manage marine socio-ecosystems for their sustainability and resilience. However, the ways by which to operationalize ecosystem-based fisheries management (EBFM) remain poorly specified. We propose a specific methodological framework—viability modelling—to do so. We show how viability modelling can be applied using four contrasted case-studies: two small-scale fisheries in South America and Pacific and two larger-scale fisheries in Europe and Australia. The four fisheries are analysed using the same modelling framework, structured around a set of common methods, indicators and scenarios. The calibrated models are dynamic, multispecies and multifleet and account for various sources of uncertainty. A multicriteria evaluation is used to assess the scenarios’ outcomes over a long time horizon with different constraints based on ecological, social and economic reference points. Results show to what extent the bio-economic and ecosystem risks associated with the adoption of status quo strategies are relatively high and challenge the implementation of EBFM. In contrast, strategies called ecoviability or co-viability strategies, that aim at satisfying the viability constraints, reduce significantly these ecological and economic risks and promote EBFM. The gains associated with those ecoviability strategies, however, decrease with the intensity of regulations imposed on these fisheries. © 2017 John Wiley & Sons Ltd

Amazon forests, which store ∼ 50% of tropical forest carbon and play a vital role in global water, energy, and carbon cycling, are predicted to experience both longer and more intense dry seasons by the end of the 21st century. However, the climate sensitivity of this ecosystem remains uncertain: several studies have predicted large-scale die-back of the Amazon, whereas several more recent studies predict that the biome will remain largely intact. Combining remote-sensing and ground-based observations with a size- and age-structured terrestrial ecosystem model, we explore the sensitivity and ecological resilience of these forests to changes in climate. We demonstrate that water stress operating at the scale of individual plants, combined with spatial variation in soil texture, explains observed patterns of variation in ecosystem biomass, composition, and dynamics across the region, and strongly influences the ecosystem's resilience to changes in dry season length. Specifically, our analysis suggests that in contrast to existing predictions of either stability or catastrophic biomass loss, the Amazon forest's response to a drying regional climate is likely to be an immediate, graded, heterogeneous transition from high-biomass moist forests to transitional dry forests and woody savannah-like states. Fire, logging, and other anthropogenic disturbances may, however, exacerbate these climate change-induced ecosystem transitions.

Understanding the resilience of moist tropical forests to treefall disturbance events is important for understanding the mechanisms that underlie species coexistence and for predicting the future composition of these ecosystems. Here, we test whether variation in the functional composition of Amazonian forests determines their resilience to disturbance. We studied the legacy of natural treefall disturbance events in four forests across Amazonia that differ substantially in functional composition. We compared the composition and diversity of all free-standing woody stems 2-10 cm diameter in previously disturbed and undisturbed 20 × 20 m subplots within 55, one-hectare, long-term forest inventory plots. Overall, stem number increased following disturbance, and species and functional composition shifted to favour light-wooded, small-seeded taxa. Alpha-diversity increased, but beta-diversity was unaffected by disturbance, in all four forests. Changes in response to disturbance in both functional composition and alpha-diversity were, however, small (2 - 4% depending on the parameter) and similar among forests. Synthesis. This study demonstrates that variation in the functional composition of Amazonian forests does not lead to large differences in the response of these forests to treefall disturbances, and overall, these events have a minor role in maintaining the diversity of these ecosystems. Understanding how the diversity of tropical forests responds to treefall disturbance events is important for understanding mechanisms of species coexistence and for predicting the future composition of these ecosystems. Previous studies have focussed on single sites and have contradictory results. By studying four sites in Amazonia, we demonstrate that these events have a consistent, but minor, role in maintaining the diversity of these ecosystems. © 2016 British Ecological Society.

A comparative study of the Sine-saloum (Senegal) and Gambia (The Gambia) estuaries was performed based on trophic model outputs that describe the system structure and functioning. These trophic models were constructed such as to differentiate main energetic flows in the systems and express how climate change may have impacted ecosystem resilience to change. Estuarine fish assemblages are highly resilient despite exposure to vast hydrodynamic variations and stress. Coupled with strong anthropogenic-driven stresses such as fisheries and climate change, ecosystems may undergo severe regime shifts that may weaken their resilience and stability. Taxonomically related and morphologically similar species do not necessarily play similar ecological roles in these two ecosystems. Biomass and production in the Sine-saloum are concentrated at trophic levels (TLs) 2 and 3, while for the Gambia, both are concentrated at TL3. Higher TL biomasses in Gambia compared to Sine-Saloum may be explained by the latter ecosystem being characterized by inverse hypersalinity. Higher TL of production in Sine-Saloum is due to higher exploitations compared to Gambia where fishing activities are still less developed. High production and consumption rates of some groups in both ecosystems indicate high system productivity. Elevated productivity may be due to higher abundance of juvenile fishes in most groups that utilize the latter as refuge and/or nursery zones. Both ecosystems are phytoplankton-driven. Differences in group trophic and ecological roles are mainly due to adaptive responses of these species to seasonal and long-term climate and anthropogenic stressors. System indicators suggest different levels of ecosystem resilience and stability as a function of biodiversity. Relevance of other observations on ecosystem functioning and indicators in relation to perturbation is discussed.

It remains unclear whether biodiversity buffers ecosystems against climate extremes, which are becoming increasingly frequent worldwide1. Early results suggested that the ecosystem productivity of diverse grassland plant communities was more resistant, changing less during drought, and more resilient, recovering more quickly after drought, than that of depauperate communities2. However, subsequent experimental tests produced mixed results3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13. Here we use data from 46 experiments that manipulated grassland plant diversity to test whether biodiversity provides resistance during and resilience after climate events. We show that biodiversity increased ecosystem resistance for a broad range of climate events, including wet or dry, moderate or extreme, and brief or prolonged events. Across all studies and climate events, the productivity of low-diversity communities with one or two species changed by approximately 50% during climate events, whereas that of high-diversity communities with 16–32 species was more resistant, changing by only approximately 25%. By a year after each climate event, ecosystem productivity had often fully recovered, or overshot, normal levels of productivity in both high- and low-diversity communities, leading to no detectable dependence of ecosystem resilience on biodiversity. Our results suggest that biodiversity mainly stabilizes ecosystem productivity, and productivity-dependent ecosystem services, by increasing resistance to climate events. Anthropogenic environmental changes that drive biodiversity loss thus seem likely to decrease ecosystem stability14, and restoration of biodiversity to increase it, mainly by changing the resistance of ecosystem productivity to climate events.

Climate change is leading to an increasing in the frequency and intensity of extreme weather events, which significantly affect ecosystems stability. In this study, ecological stability metrics in response to wet/dry events and warm/cold events on vegetation greenness were assessed using an auto-regressive model of NDVI in the Mekong River basin (around 759,000 km2) where large ecological and climatic gradients exist. Gridded temperature, and the Global Standard Precipitation Evaporation Index (SPEI) and antecedent NDVI were used as model predictors. The forest in north Laos was more resilient to the temperate and wet/dry anomalies events than other regions in the basin. Drought reduced green biomass in north Laos, northeast Thailand and Myanmar, but in these tropical climate regions' the vegetation biomass was also more responsive by higher temperatures. Vegetation in northeast Thailand, Cambodia and the Mekong delta were less sensitive to the temperature anomalies effect compared to other part of Mekong River basin. The map of resistance and resilience metrics can help to determine the most vulnerable regions to extreme events for policy makers.

The assessment of total economic value has become a pragmatic and popular approach in nature valuation, yet criticisms have been raised. One major point of critique is that total economic value bases the monetary value of ecosystems purely on the flow of human benefits of services of ecosystems and consequently ignores questions of sustainable use of natural capital per se. This paper explains why total economic value by itself is in principle an inadequate concept to guide sustainable use of ecosystems and gives an overview of essential ecological theory that needs to be taken into account in addition to total economic value to fully include ecosystem sustainability. The paper concludes with a framework for combining ecological theory with economic valuation. The key elements here are theoretical ecological insights about ecosystem resilience and portfolio theory which offers an economic perspective on investment in biodiversity. Portfolio theory puts total economic value in a framework where investment in biodiversity is expanded to cover functional diversity and mobile link species in order to maintain ecosystem resilience and so fosters sustainable use of ecosystems. © 2013 Elsevier B.V.

La surexploitation des ressources naturelles, consécutive à un besoin accru en terres arables des populations locales, entraîne de graves dysfonctionnements dans le bio-fonctionnement du sol (carences minérales, stress salins, etc.). Ce dysfonctionnement, aggravé par les aléas climatiques (sécheresse), nécessite la mise en oeuvre de stratégies d'ingénierie écologique permettant une réhabilitation des milieux dégradés via la restauration de services écologiques essentiels. Les premiers symptômes du processus d'altération de la qualité des sols des milieux tropicaux et méditerranéens se traduisent par une altération de la structure de la strate épigée avec, en particulier, une paupérisation de la diversité et de l'abondance des espèces végétales. Cette dégradation est accompagnée par une fragilisation des sols et une augmentation de l'impact de l'érosion sur la couche superficielle, entraînant une baisse de la fertilité des sols au niveau de leurs caractéristiques physico-chimiques, mais aussi biologiques (par exemple, la microflore tellurique). Parmi les composantes microbiennes particulièrement sensibles à ces phénomènes d'érosion, les microorganismes symbiotiques (rhizobia, champignons mycorhiziens) sont connus pour être des composantes clés dans le fonctionnement des principaux cycles biogéochimiques telluriques (C, N et P). De nombreux travaux ont montré l'importance de la gestion de ces microorganismes symbiotiques dans les stratégies de réhabilitation et de revégétalisation des milieux dégradés, mais également pour améliorer la productivité des agro-systèmes. En particulier, la sélection de symbiotes et leur inoculation en masse dans le sol de plantation ou de culture ont été fortement encouragées au cours de ces dernières décennies. Ces inoculants étaient sélectionnés, non seulement pour leur impact sur la plante, mais également pour leur capacité à persister dans le sol, au détriment de la microflore résiduelle native. La performance de cette technique était donc évaluée au niveau du couvert végétal, mais les répercussions au niveau des caractéristiques de la microflore tellurique étaient généralement ignorées. Le rôle de la diversité microbienne sur la productivité et la stabilité (résistance, capacité de résilience, etc.) des éco- et agro-systèmes a été mis en évidence relativement récemment et a conduit à une remise en cause des bases conceptuelles de l'inoculation contrôlée dans la gestion durable des terres. Il a été notamment suggéré que les caractéristiques du milieu à réhabiliter devaient être prises en compte, et plus particulièrement son niveau de dégradation par rapport au seuil de résilience écologique. Cette prise en compte devrait permettre d'optimiser les pratiques culturales pour soit (i) redonner à l'écosystème ses propriétés originelles dans le cas de milieux peu dégradés ou (ii) transformer un écosystème dans le cas de sols hautement dégradés (par exemple, les sols miniers). Dans ce chapitre, nous évoquerons, à travers différents exemples d'expérimentations réalisées en milieu tropical et méditerranéen, les performances des différentes stratégies de gestion du potentiel microbien des sols (inoculation d'espèces exotiques vs des espèces natives, inoculation contrôlée vs la gestion du potentiel microbien via la strate végétale épigée, etc.) suivant le niveau de dégradation du milieu.

Deltas and estuaries built by the Mississippi/Atchafalaya River (MAR) in the United States and the Usumacinta/Grijalva River (UGR) in Mexico account for 80 percent of all Gulf of Mexico (GoM) coastal wetlands outside of Cuba. They rank first and second in freshwater discharge to the GoM and owe their natural resilience to a modular geomorphology that spreads risk across the coast-scape while providing ecosystem connectivity through shelf plumes that connect estuaries. Both river systems generate large plumes that strongly influence fisheries production over large areas of the northern and southern GoM continental shelves. Recent watershed process simulations (DLEM, MAPSS) driven by CMIP3 General Circulation Model (GCM) output indicate that the two systems face diverging futures, with the mean annual discharge of the MAR predicted to increase 11 to 63 percent, and that of the UGR to decline as much as 80 percent in the 21st century. MAR delta subsidence rates are the highest in North America, making it particularly susceptible to channel training interventions that have curtailed a natural propensity to shift course and deliver sediment to new areas, or to refurbish zones of high wetland loss. Undoing these restrictions in a controlled way has become the focus of a multi-billion-dollar effort to restore the MAR delta internally, while releasing fine-grained sediments trapped behind dams in the Great Plains has become an external goal. The UGR is, from an internal vulnerability standpoint, most threatened by land use changes that interfere with a deltaic architecture that is naturally resilient to sea level rise. This recognition has led to successful efforts in Mexico to protect still intact coastal systems against further anthropogenic impacts, as evidenced by establishment of the Centla Wetland Biosphere Preserve and the Terminos Lagoon Protected Area. The greatest threat to the UGR system, however, is an external one that will be imposed by the severe drying predicted for the entire Mesoamerican “climate change hot-spot”, a change that will necessitate much greater international involvement to protect threatened communities and lifeways as well as rare habitats and species.

International audience; The environment is impacted by natural and anthropogenic disturbances that occur at different spatial and temporal scales, and that lead to major changes and even disequilibria when exceeding the resiliency capacities of the ecosystem. With an annual mean flow of 1700 m3 s-1, the Rhône River is the largest of the western Mediterranean basin. Its annual solid discharges vary between 2 and 20 Mt, with flood events responsible for more than 70% of these amounts. In the marine coastal area, close to the mouth, both flocculation and aggregation lead to the formation of fine-grained deposits, i.e. the prodelta. This area is characterized by sediment accumulation rates up to 20-50 cm yr-1 and high accumulations of particle reactive contaminants such as various man-made radionuclides released into the river by nuclear facilities or arising form prior atmospheric nuclear tests (1954-1980) and the Chernobyl accident (April 1986). This prodelta, however, cannot be considered as a permanent repository for particle reactive pollutants since it is subjected to reworking processes. Sediment dynamics had to be linked to the influences of hydrodynamic and atmospheric events such as high flow rates or storms close to the Rhône River mouth. An experiment was carried out during the winter 2006 based on the deployment of two ADCPs and six altimeters at the Grand Rhône mouth for several months. This type of installation has never been used before in this area because of the hard meteorological conditions and the strong fishing activities. However, results showed pluricentimetric rises of the sedimentary level just after river flood events and decreases during storms, generated by southeast winds. Radiotracers and grain size depth profiles helped to characterise the studied events and to establish inventories of sediments and radionuclides. A cruise (CARMEX) was carried out during this same period to collect water samples, suspended particles and sediment cores. The results enabled us to link both river flow and wind characteristics to events recorded on the sea floor, i.e. resuspension, accumulation, consolidation, etc. Deposits of 11 cm of sediments were estimated during flood periods and bottom shear stresses up to 5 N m-2 were calculated during sediment erosion phases. © 2010 Elsevier Ltd. All rights reserved.

A fertilisation experiment was started in the French Alps on an acid grassland at 2000 m in 1989 where lime as calcium carbonate (“liming”) and Thomas Slag enriched by potassium chloride (“fertilisation”) were added in a random block design until 1992. Since then, no further amendments were applied. Fifteen years after the last application, we revisited the experiment and observed that soil pH was still significantly higher on limed plots, while nitrogen (N) concentrations were lower. On fertilised plots, soil carbon (C) and N concentrations were lower compared to unfertilised plots. However, litter quality (C and N concentrations, near infrared spectroscopy [NIRS] data) was similar for both treatments. Vegetation composition, but not species richness, nor Shannon–Wiener or evenness differed between limed and unlimed plots, and fertilised and unfertilised plots. Liming explained about 18% and fertilisation about 6% of the variability of the vegetation composition. These changes in the vegetation composition are probably due to lower abundances of former dominant grass species and to an increase in generalist grasses. However, these changes did not influence the total above-ground productivity, which was similar for all treatments. Tissue N and C concentrations and NIRS data indicated a changed chemical composition of the biomass which persisted during time. We conclude that the 3 years of fertilisation and liming did substantially influence the vegetation composition at our site and lead to an increase in the agricultural value of the grassland. These changes are long-lasting as they changed key features of the functioning in the soil of grasslands ecosystems. From an ecological point of view, specialised vegetation was replaced by generalist species leading to a trivialisation of the vegetation.

International audience; Monitoring coral reef communities at a decadal scale is necessary to understand and project their dynamics to provide a basis for reef management in light of disturbances and climate change. Complementing infrequent and localised in situ observations, time-series of aerial photographs and remotely sensed satellite images provide a means of monitoring the position and extent of reef-top coral communities, vegetation and abiotic substrata at the whole reef scale. The aim of the present study was to map such changes on Saint-Leu Reef (La Réunion) between 1973 and 2007. The period included two cyclones (1989, 2002) and one severe bleaching event (2002). Vertical images of the reef were recorded in five aerial photographs (1973, 1978, 1989, 1997, and 2003) and two Quickbird satellite images (2002, 2006) during that time. Quantitative in situ observations of parts of the reef-top were also available both to document ecological and substratum characteristics that produce the color and texture observable in the photos and satellite images. Coral communities were mapped on all images using manual delineation of polygons identified according to color and texture contrast. The 2006 Quickbird image was used as the mapping base and 15 types of coral communities were identified from a reef survey conducted in 2007. This hierarchical typology used coral growth forms, live and dead coral cover, macro-algae, substratum (sand, rubble and platform) and, to a lesser extent, coral taxonomy. The polygons at date t were over-laid onto image t − 1 across the whole series and their boundaries were manually edited to match the pattern on the earlier image. Labelling of polygons was guided by field-survey data and maps. For coral-dominated patches, six successive pairs of maps from 1973 to 2006 were compared to produce 'coral community change maps' for that period. Despite the multiple disturbance events, the coral community distribution and composition in 2006 on Saint-Leu Reef did not display major differences compared to 1973. This suggests a high degree of coral resilience at the site, led by rapid recovery of compact branching corals. The mapping techniques overcame challenges due to different image quality and the sparsity of in situ observations in time and space. Our results demonstrate the potential for further application of reef monitoring protocols based on complementary in situ and remote-sensing data to help understand the dynamics of reef-top coral reef communities and geomorphology over years to decades.

During four decades, the Ria de Aveiro was subjected to the loading of mercury from a chlor-alkali industry, resulting in the deposition of several tons of mercury in the sediments. The present study evaluates the impact of this disturbance and the recovery processes, temporally and spatially, by means of examining the richness of the species of salt marsh plants and mercury concentrations in sediments over the last fifty years. The temporal assessment showed that the mercury loading induced a shift in the species composition of the salt marsh from a non-disturbed salt marsh with higher species richness to an alternative state dominated by Phragmites australis. The horizontal assessment, through a mercury gradient, presents the same trend, indicating that P. australis is the species most tolerant to higher mercury concentrations, comparative to Halimione portulacoides, Arthrocnemum fruticosum, Triglochin maritima, Juncus maritimus and Scirpus maritimus. After the reduction of mercury discharges in 1994, the salt marsh shows a slowly return path recovery response. The hysteresis in the response results in the temporal gap between the reduction in mercury concentrations in the sediment and the salt marsh species richness response, comparatively to the existing diversity in the local reference marsh. http://www.sciencedirect.com/science/article/B6V74-4R8M09D-2/1/1da80b1f6cad6e36f85e4a8c58552055

We studied the Holocene developmental history of a small kettle-hole peatland in northern Poland using radiocarbon dating and analyses of pollen, plant macrofossils, and testate amoebae with the aim to sort out the influences of climate change, autogenic succession, and human impact. The mire followed the classical succession from lake to a Sphagnum-dominated peatland, but peat accumulation only started about 3000 years before present. A rapid shift to wetter conditions, lower pH, and higher peat accumulation rate took place about 110-150 years before present, when the vegetation shifted to a Sphagnum-dominated poor fen with some bog plants. While the first shift to a peat-accumulating system was most likely driven by climate, the second one was probably caused by forest clearance around the mire. This shift towards a Sphagnum-dominated vegetation mirrors both in pattern and timing the changes observed in similar situations in North America and New-Zealand. While human activities have overall caused the loss of vast expanses of peatlands worldwide in recent centuries, locally they may have also allowed the development of communities that are now ironically considered to have a high conservation value. However, in the case of the site studied and possibly elsewhere the likely anthropogenic shift to bog vegetation was at the expense of a species-rich poor fen, which today has even higher conservation value than ombrotrophic bogs. Thus this study also illustrates the value of palaeoecology for peatland management and biodiversity conservation.