Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N ...deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now and in the future. This synthesis paper clearly shows that N accumulation is the main driver of changes to species composition across the whole range of different ecosystem types by driving the competitive interactions that lead to composition change and/or making conditions unfavorable for some species. Other effects such as direct toxicity of nitrogen gases and aerosols, long-term negative effects of increased ammonium and ammonia availability, soil-mediated effects of acidification, and secondary stress and disturbance are more ecosystem- and site-specific and often play a supporting role. N deposition effects in mediterranean ecosystems have now been identified, leading to a first estimate of an effect threshold. Importantly, ecosystems thought of as not N limited, such as tropical and subtropical systems, may be more vulnerable in the regeneration phase, in situations where heterogeneity in N availability is reduced by atmospheric N deposition, on sandy soils, or in montane areas. Critical loads are effect thresholds for N deposition, and the critical load concept has helped European governments make progress toward reducing N loads on sensitive ecosystems. More needs to be done in Europe and North America, especially for the more sensitive ecosystem types, including several ecosystems of high conservation importance. The results of this assessment show that the vulnerable regions outside Europe and North America which have not received enough attention are ecoregions in eastern and southern Asia (China, India), an important part of the mediterranean ecoregion (California, southern Europe), and in the coming decades several subtropical and tropical parts of Latin America and Africa. Reductions in plant diversity by increased atmospheric N deposition may be more widespread than first thought, and more targeted studies are required in low background areas, especially in the G200 ecoregions.
1. Ecosystem services are defined as the benefits that humans obtain from ecosystems. Employing the ecosystem service concept is intended to support the development of policies and instruments that ...integrate social, economic and ecological perspectives. In recent years, this concept has become the paradigm of ecosystem management. 2. The prolific use of the term 'ecosystem services' in scientific studies has given rise to concerns about its arbitrary application. A quantitative review of recent literature shows the diversity of approaches and uncovers a lack of consistent methodology. 3. From this analysis, we have derived four facets that characterise the holistic ideal of ecosystem services research: (i) biophysical realism of ecosystem data and models; (ii) consideration of local trade-offs; (iii) recognition of off-site effects; and (iv) comprehensive but critical involvement of stakeholders within assessment studies. 4. These four facets should be taken as a methodological blueprint for further development and discussion. They should critically reveal and elucidate what may often appear to be ad-hoc approaches to ecosystem service assessments. 5. Synthesis and applications: Based on this quantitative review, we provide guidelines for further development and discussions supporting consistency in applications of the ecosystem service concept as well as the credibility of results, which in turn can make it easier to generalise from the numerous individual studies.
Kelp forests represent some of the most diverse and productive habitats on Earth, and provide a range of ecosystem goods and services on which human populations depend. As the distribution and ...ecophysiology of kelp species is strongly influenced by temperature, recent warming trends in many regions have been linked with concurrent changes in kelp populations, communities and ecosystems. Over the past decade, the number of reports of ocean warming impacts on kelp forests has risen sharply. Here, I synthesise recent studies to highlight general patterns and trends. While kelp responses to climate change vary greatly between ocean basins, regions and species, there is compelling evidence to show that ocean warming poses an unequivocal threat to the persistence and integrity of kelp forest ecosystems in coming decades.
In recent years there has been an upsurge of studies on ecosystem multifunctionality (EMF), or the ability of ecosystems to simultaneously provide multiple functions and/or services. The concept of ...EMF itself, the analytical approaches used to calculate it, and its implications depending on the spatial scale and field of study have been discussed in detail. However, to date there has been little dialogue concerning the basis of EMF studies: what should or should not be considered appropriate measures for ecosystem functions.
To begin this discussion, we performed an in‐depth review of EMF studies across four major terrestrial ecosystems (agroecosystems, drylands, forests and grasslands) by analysing 82 studies, which together have assessed 775 ecosystem functions from a variety of field and greenhouse experiments across the globe.
The number of ecosystem functions analysed varied from two to 82 per study and we found large differences in the distribution of functions across ecosystem types and ecosystem service categories. Furthermore, there was little explanation of why certain variables were included in the EMF calculation or how they relate to ecosystem functioning.
Synthesis. Based on the literature analysis, it is clear that there is no general agreement regarding which measurements should or should not be considered functions in the field of ecology. To address this issue, we propose a general guideline for determining and measuring appropriate functions.
In recent years there has been an upsurge of studies on ecosystem multifunctionality (EMF), or the ability of ecosystems to simultaneously provide multiple functions and/or services. The concept of EMF itself, the analytical approaches used to calculate it and its implications depending on the spatial scale and field of study have been discussed in detail. However, to date, there has been little dialogue concerning the basis of EMF studies‐ the functions themselves‐ nor what appropriate measures for ecosystem functions are. To begin this discussion, we performed an in‐depth review of EMF studies across four major terrestrial ecosystems (agroecosystems, drylands, forests and grasslands) by analysing 82 studies, which together have assessed 775 ecosystem functions from a variety of field and greenhouse experiments across the globe. The number of ecosystem functions analysed varied from two to 82 per study and we found large differences in the distribution of functions across ecosystem types. Furthermore, there was little explanation of why certain variables were included in the EMF calculation or how they relate to ecosystem functioning. Based on the literature analysis, we propose a general guideline for determining and measuring appropriate functions.
Global Map of Human Impact on Marine Ecosystems Halpern, Benjamin S; Walbridge, Shaun; Selkoe, Kimberly A ...
Science (American Association for the Advancement of Science),
02/2008, Letnik:
319, Številka:
5865
Journal Article
Recenzirano
The management and conservation of the world's oceans require synthesis of spatial data on the distribution and intensity of human activities and the overlap of their impacts on marine ecosystems. We ...developed an ecosystem-specific, multiscale spatial model to synthesize 17 global data sets of anthropogenic drivers of ecological change for 20 marine ecosystems. Our analysis indicates that no area is unaffected by human influence and that a large fraction (41%) is strongly affected by multiple drivers. However, large areas of relatively little human impact remain, particularly near the poles. The analytical process and resulting maps provide flexible tools for regional and global efforts to allocate conservation resources; to implement ecosystem-based management; and to inform marine spatial planning, education, and basic research.
Ecosystem-based management is logistically and politically challenging because ecosystems are inherently complex and management decisions affect a multitude of groups. Coastal ecosystems, which lie ...at the interface between marine and terrestrial ecosystems and provide an array of ecosystem services to different groups, aptly illustrate these challenges. Successful ecosystem-based management of coastal ecosystems requires incorporating scientific information and the knowledge and views of interested parties into the decision-making process. Estimating the provision of ecosystem services under alternative management schemes offers a systematic way to incorporate biogeophysical and socioeconomic information and the views of individuals and groups in the policy and management process. Employing ecosystem services as a common language to improve the process of ecosystem-based management presents both benefits and difficulties. Benefits include a transparent method for assessing trade-offs associated with management alternatives, a common set of facts and common currency on which to base negotiations, and improved communication among groups with competing interests or differing worldviews. Yet challenges to this approach remain, including predicting how human interventions will affect ecosystems, how such changes will affect the provision of ecosystem services, and how changes in service provision will affect the welfare of different groups in society. In a case study from Puget Sound, Washington, we illustrate the potential of applying ecosystem services as a common language for ecosystem-based management.
Human activities are rapidly changing ecosystems, landscapes and ecosystem service provision, yet there remain significant gaps in our understanding of the spatial ecology of ecosystem services. ...These gaps hinder our ability to manage landscapes effectively for multiple ecosystem services. In particular, we do not fully understand how changes in landscape connectivity affect ecosystem service provision, despite theory suggesting that connectivity is important. Here, we perform a semi-quantitative review of the literature that investigates how landscape connectivity affects the provision of specific ecosystem services. The vast majority of studies, including reviews, models, and field studies, suggest that decreased connectivity will have negative effects on ecosystem service provision. However, only 15 studies provided empirical evidence of these effects. Average effect sizes from these 15 studies suggest negative effects of connectivity loss on pollination and pest regulation. We identify a number of significant gaps in the connectivity-ecosystem services literature, including: a lack of multiple service studies, which precludes identification of tradeoffs between services as connectivity changes; few studies that directly measure organism movement and its effects on ecosystem services; and few empirical studies that investigate the importance of abiotic flows on service provision. We propose that future research should aim to understand how different aspects of connectivity affect ecosystem service provision; which services are most influenced by connectivity; and how connectivity influences how humans access and benefit from ecosystem services. Studies that answer these questions will advance our understanding of connectivity-ecosystem service provision relationships and allow for better ecosystem and landscape management and restoration.
In this review we highlight the relevance of biodiversity that inhabit coastal lagoons, emphasizing how species functions foster processes and services associated with this ecosystem. We identified ...26 ecosystem services underpinned by ecological functions performed by bacteria and other microbial organisms, zooplankton, polychaetae worms, mollusks, macro-crustaceans, fishes, birds, and aquatic mammals. These groups present high functional redundancy but perform complementary functions that result in distinct ecosystem processes. Because coastal lagoons are located in the interface between freshwater, marine and terrestrial ecosystems, the ecosystem services provided by the biodiversity surpass the lagoon itself and benefit society in a wider spatial and historical context. The species loss in coastal lagoons due to multiple human-driven impacts affects the ecosystem functioning, influencing negatively the provision of all categories of services (i.e., supporting, regulating, provisioning and cultural). Because animals’ assemblages have unequal spatial and temporal distribution in coastal lagoons, it is necessary to adopt ecosystem-level management plans to protect habitat heterogeneity and its biodiversity, ensuring the provision of services for human well-being to multi-actors in the coastal zone.
As an inevitable consequence of increased environmental degradation and anticipated future environmental change, societal demand for ecosystem restoration is rapidly increasing. Here, I evaluate ...successes and failures in restoration, how science is informing these efforts, and ways to better address decision-making and policy needs. Despite the multitude of restoration projects and wide agreement that evaluation is a key to future progress, comprehensive evaluations are rare. Based on the limited available information, restoration outcomes vary widely. Cases of complete recovery are frequently characterized by the persistence of species and abiotic processes that permit natural regeneration. Incomplete recovery is often attributed to a mixture of local and landscape constraints, including shifts in species distributions and legacies of past land use. Lastly, strong species feedbacks and regional shifts in species pools and climate can result in little to no recovery. More forward-looking paradigms, such as enhancing ecosystem services and increasing resilience to future change, are exciting new directions that need more assessment. Increased evidence-based evaluation and cross-disciplinary knowledge transfer will better inform a wide range of critical restoration issues such as how to prioritize sites and interventions, include uncertainty in decision making, incorporate temporal and spatial dependencies, and standardize outcome assessments. As environmental policy increasingly embraces restoration, the opportunities have never been greater.
ABSTRACT
Non‐native tree (NNT) species have been transported worldwide to create or enhance services that are fundamental for human well‐being, such as timber provision, erosion control or ornamental ...value; yet NNTs can also produce undesired effects, such as fire proneness or pollen allergenicity. Despite the variety of effects that NNTs have on multiple ecosystem services, a global quantitative assessment of their costs and benefits is still lacking. Such information is critical for decision‐making, management and sustainable exploitation of NNTs. We present here a global assessment of NNT effects on the three main categories of ecosystem services, including regulating (RES), provisioning (PES) and cultural services (CES), and on an ecosystem disservice (EDS), i.e. pollen allergenicity. By searching the scientific literature, country forestry reports, and social media, we compiled a global data set of 1683 case studies from over 125 NNT species, covering 44 countries, all continents but Antarctica, and seven biomes. Using different meta‐analysis techniques, we found that, while NNTs increase most RES (e.g. climate regulation, soil erosion control, fertility and formation), they decrease PES (e.g. NNTs contribute less than native trees to global timber provision). Also, they have different effects on CES (e.g. increase aesthetic values but decrease scientific interest), and no effect on the EDS considered. NNT effects on each ecosystem (dis)service showed a strong context dependency, varying across NNT types, biomes and socio‐economic conditions. For instance, some RES are increased more by NNTs able to fix atmospheric nitrogen, and when the ecosystem is located in low‐latitude biomes; some CES are increased more by NNTs in less‐wealthy countries or in countries with higher gross domestic products. The effects of NNTs on several ecosystem (dis)services exhibited some synergies (e.g. among soil fertility, soil formation and climate regulation or between aesthetic values and pollen allergenicity), but also trade‐offs (e.g. between fire regulation and soil erosion control). Our analyses provide a quantitative understanding of the complex synergies, trade‐offs and context dependencies involved for the effects of NNTs that is essential for attaining a sustained provision of ecosystem services.
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