Showing papers on "Ecosystem published in 2019"
TL;DR: In this article, the authors manipulated the soil microbiome in experimental grassland ecosystems and observed that microbiome diversity and microbial network complexity positively influenced multiple ecosystem functions related to nutrient cycling (e.g. multifunctionality).
Abstract: The soil microbiome is highly diverse and comprises up to one quarter of Earth’s diversity. Yet, how such a diverse and functionally complex microbiome influences ecosystem functioning remains unclear. Here we manipulated the soil microbiome in experimental grassland ecosystems and observed that microbiome diversity and microbial network complexity positively influenced multiple ecosystem functions related to nutrient cycling (e.g. multifunctionality). Grassland microcosms with poorly developed microbial networks and reduced microbial richness had the lowest multifunctionality due to fewer taxa present that support the same function (redundancy) and lower diversity of taxa that support different functions (reduced functional uniqueness). Moreover, different microbial taxa explained different ecosystem functions pointing to the significance of functional diversity in microbial communities. These findings indicate the importance of microbial interactions within and among fungal and bacterial communities for enhancing ecosystem performance and demonstrate that the extinction of complex ecological associations belowground can impair ecosystem functioning.
595 citations
ETH Zurich1, University of California, Davis2, Bielefeld University3, Nanyang Technological University4, Wageningen University and Research Centre5, Brigham Young University6, Aligarh Muslim University7, Colorado State University8, University of Manchester9, University of Cologne10, University of La Rioja11, University of Brasília12, Queen's University Belfast13, Nanjing Agricultural University14, University of Minho15, Empresa Brasileira de Pesquisa Agropecuária16, Zealand Institute of Business and Technology17, Spanish National Research Council18, Scotland's Rural College19, American Museum of Natural History20, Russian Academy of Sciences21, Swedish University of Agricultural Sciences22, University of Göttingen23, Chinese Academy of Sciences24, University of Catania25, University of Nebraska–Lincoln26, James Hutton Institute27, Vietnam Academy of Science and Technology28, University of Sydney29, Bulgarian Academy of Sciences30, Universidade Federal de Lavras31, University of Helsinki32, University of Montpellier33, Aarhus University34, Lancaster University35, National Taiwan University36
TL;DR: High-resolution spatial maps of the global abundance of soil nematodes and the composition of functional groups show that soil nematode are found in higher abundances in sub-Arctic regions, than in temperate or tropical regions.
Abstract: Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.
552 citations
TL;DR: It is shown that microbial necromass can make up more than half of soil organic carbon, and it is suggested next-generation field management requires promoting microbial biomass formation and necromassing preservation to maintain healthy soils, ecosystems, and climate.
Abstract: Soil carbon transformation and sequestration have received significant interest in recent years due to a growing need for quantitating its role in mitigating climate change. Even though our understanding of the nature of soil organic matter has recently been substantially revised, fundamental uncertainty remains about the quantitative importance of microbial necromass as part of persistent organic matter. Addressing this uncertainty has been hampered by the absence of quantitative assessments whether microbial matter makes up the majority of the persistent carbon in soil. Direct quantitation of microbial necromass in soil is very challenging because of an overlapping molecular signature with nonmicrobial organic carbon. Here, we use a comprehensive analysis of existing biomarker amino sugar data published between 1996 and 2018, combined with novel appropriation using an ecological systems approach, elemental carbon-nitrogen stoichiometry, and biomarker scaling, to demonstrate a suit of strategies for quantitating the contribution of microbe-derived carbon to the topsoil organic carbon reservoir in global temperate agricultural, grassland, and forest ecosystems. We show that microbial necromass can make up more than half of soil organic carbon. Hence, we suggest that next-generation field management requires promoting microbial biomass formation and necromass preservation to maintain healthy soils, ecosystems, and climate. Our analyses have important implications for improving current climate and carbon models, and helping develop management practices and policies.
494 citations
University of Würzburg1, National University of Comahue2, Spanish National Research Council3, Swedish University of Agricultural Sciences4, University of Lisbon5, Universidade Federal de Goiás6, Stanford University7, Commonwealth Scientific and Industrial Research Organisation8, National University of Río Negro9, ETH Zurich10, Cornell University11, University of California, Davis12, The Nature Conservancy13, Wageningen University and Research Centre14, University of British Columbia15, Great Lakes Bioenergy Research Center16, University of California, Santa Cruz17, University of Padua18, University of New England (Australia)19, Lund University20, University of Göttingen21, Institut national de la recherche agronomique22, University of La Rochelle23, Federal University of Ceará24, University of Freiburg25, Concordia University Wisconsin26, University of Belgrade27, National University of Tucumán28, Michigan State University29, University of Brasília30, University of Greenwich31, University of Reading32, University of Wisconsin-Madison33, National Institute of Amazonian Research34, Boise State University35, University of Texas at Austin36, University of Haifa37, Kansas State University38, University of Hamburg39, Bioversity International40, University of California, Santa Barbara41, Seattle University42, University of Vienna43, University of Florida44, Centro Agronómico Tropical de Investigación y Enseñanza45, National Audubon Society46, University of Buenos Aires47, Virginia Tech48, University of Bordeaux49, University of Auckland50, University of California, Berkeley51, University College Dublin52, Trinity College, Dublin53, University of Tokyo54, Federal University of Bahia55, Lincoln University (New Zealand)56, National Institute for Environmental Studies57, International Food Policy Research Institute58, Xi'an Jiaotong-Liverpool University59
TL;DR: Using a global database from 89 studies (with 1475 locations), the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change is partitioned.
Abstract: Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society.
434 citations
TL;DR: It is demonstrated that microbial community assembly was governed more by species sorting than by dispersal limitation in maize fields, and to a lesser extent in rice fields, which indicates that a balance between species sorting and disperseal limitation mediates species coexistence in soil microbiomes.
Abstract: Revealing the linkages between community assembly and species coexistence, which is crucial for the understanding of ecosystem diversity and functioning, is a fundamental but rarely investigated subject in microbial ecology. Here we examined archaeal, bacterial, and fungal community assembly in adjacent pairs of maize (water-unsaturated) and rice (water-saturated) fields across different habitats and regions throughout Eastern China. The high-throughput sequencing dataset was analyzed by variation partitioning, null model, and neutral community model analyses. We demonstrated that microbial community assembly was governed more by species sorting than by dispersal limitation in maize fields, and to a lesser extent in rice fields. The relative importance of species sorting in maize soils was greater at low latitudes than at high latitudes, while rice soils exhibited an opposite trend. Microbial co-occurrence associations tended to be higher when communities were primarily driven by dispersal limitation relative to species sorting. There were greater community dissimilarities between maize and rice soils in low-latitude regions, which was consistent with the higher proportion of negative edges in the correlation networks. The results indicate that a balance between species sorting and dispersal limitation mediates species coexistence in soil microbiomes. This study enhances our understanding of contemporary coexistence theory in microbial ecosystems.
393 citations
TL;DR: Earth system models suggest that soil-moisture variability and trends will induce large carbon releases throughout the twenty-first century and suggest that the increasing trend in carbon uptake rate may not be sustained past the middle of the century and could result in accelerated atmospheric CO2 growth.
Abstract: Although the terrestrial biosphere absorbs about 25 per cent of anthropogenic carbon dioxide (CO2) emissions, the rate of land carbon uptake remains highly uncertain, leading to uncertainties in climate projections1,2. Understanding the factors that limit or drive land carbon storage is therefore important for improving climate predictions. One potential limiting factor for land carbon uptake is soil moisture, which can reduce gross primary production through ecosystem water stress3,4, cause vegetation mortality5 and further exacerbate climate extremes due to land–atmosphere feedbacks6. Previous work has explored the impact of soil-moisture availability on past carbon-flux variability3,7,8. However, the influence of soil-moisture variability and trends on the long-term carbon sink and the mechanisms responsible for associated carbon losses remain uncertain. Here we use the data output from four Earth system models9 from a series of experiments to analyse the responses of terrestrial net biome productivity to soil-moisture changes, and find that soil-moisture variability and trends induce large CO2 fluxes (about two to three gigatons of carbon per year; comparable with the land carbon sink itself1) throughout the twenty-first century. Subseasonal and interannual soil-moisture variability generate CO2 as a result of the nonlinear response of photosynthesis and net ecosystem exchange to soil-water availability and of the increased temperature and vapour pressure deficit caused by land–atmosphere interactions. Soil-moisture variability reduces the present land carbon sink, and its increase and drying trends in several regions are expected to reduce it further. Our results emphasize that the capacity of continents to act as a future carbon sink critically depends on the nonlinear response of carbon fluxes to soil moisture and on land–atmosphere interactions. This suggests that the increasing trend in carbon uptake rate may not be sustained past the middle of the century and could result in accelerated atmospheric CO2 growth. Earth system models suggest that soil-moisture variability and trends will induce large carbon releases throughout the twenty-first century.
365 citations
University of Würzburg1, University of Bayreuth2, University of Marburg3, University of Göttingen4, University of Ulm5, University of Bern6, University of Copenhagen7, Karlsruhe Institute of Technology8, Tanzania Commission for Science and Technology9, Technische Universität München10, College of African Wildlife Management11, University of Jena12, University of Oldenburg13, University of KwaZulu-Natal14, University of Dar es Salaam15, Tanzania Wildlife Research Institute16, Goethe University Frankfurt17, Kazan Federal University18, Smithsonian Tropical Research Institute19
TL;DR: The study reveals that climate can modulate the effects of land use on biodiversity and ecosystem functioning, and points to a lowered resistance of ecosystems in climatically challenging environments to ongoing land-use changes in tropical mountainous regions.
Abstract: Agriculture and the exploitation of natural resources have transformed tropical mountain ecosystems across the world, and the consequences of these transformations for biodiversity and ecosystem functioning are largely unknown1-3. Conclusions that are derived from studies in non-mountainous areas are not suitable for predicting the effects of land-use changes on tropical mountains because the climatic environment rapidly changes with elevation, which may mitigate or amplify the effects of land use4,5. It is of key importance to understand how the interplay of climate and land use constrains biodiversity and ecosystem functions to determine the consequences of global change for mountain ecosystems. Here we show that the interacting effects of climate and land use reshape elevational trends in biodiversity and ecosystem functions on Africa's largest mountain, Mount Kilimanjaro (Tanzania). We find that increasing land-use intensity causes larger losses of plant and animal species richness in the arid lowlands than in humid submontane and montane zones. Increases in land-use intensity are associated with significant changes in the composition of plant, animal and microorganism communities; stronger modifications of plant and animal communities occur in arid and humid ecosystems, respectively. Temperature, precipitation and land use jointly modulate soil properties, nutrient turnover, greenhouse gas emissions, plant biomass and productivity, as well as animal interactions. Our data suggest that the response of ecosystem functions to land-use intensity depends strongly on climate; more-severe changes in ecosystem functioning occur in the arid lowlands and the cold montane zone. Interactions between climate and land use explained-on average-54% of the variation in species richness, species composition and ecosystem functions, whereas only 30% of variation was related to single drivers. Our study reveals that climate can modulate the effects of land use on biodiversity and ecosystem functioning, and points to a lowered resistance of ecosystems in climatically challenging environments to ongoing land-use changes in tropical mountainous regions.
275 citations
Wageningen University and Research Centre1, University of Puerto Rico2, National Autonomous University of Mexico3, Colby College4, National Institute of Amazonian Research5, University of São Paulo6, Federal University of Pernambuco7, University of Alberta8, Paul Sabatier University9, International Institute of Minnesota10, University of Connecticut11, University of Colorado Boulder12, Smithsonian Tropical Research Institute13, Tulane University14, University of Stirling15, Clemson University16, Comisión Nacional para el Conocimiento y Uso de la Biodiversidad17, Universidade Federal de Minas Gerais18, Centro Agronómico Tropical de Investigación y Enseñanza19, Alexander von Humboldt Biological Resources Research Institute20, The Catholic University of America21, Colorado Mesa University22, State University of New York at Purchase23, University of Haifa24, University of Wisconsin-Madison25, Universidade Federal do Rio Grande do Sul26, Universidade Federal de Viçosa27, Costa Rica Institute of Technology28, University of Minnesota29, Pedagogical and Technological University of Colombia30, University of California, Santa Barbara31, Museu Paraense Emílio Goeldi32, University of California, Berkeley33, Columbia University34, New York Botanical Garden35, National University of Singapore36, Yale-NUS College37, Puerto Rico Department of Agriculture38, University of Amsterdam39, Louisiana State University40, University of Puerto Rico, Río Piedras41
TL;DR: This work assesses how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics.
Abstract: Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes.
273 citations
TL;DR: By assessing and statistically scaling the climatic drivers from 2710 tree-ring sites, this work identified the boreal and temperate land areas where tree growth during 1930–1960 CE responded positively to temperature, precipitation, and other parameters, and expects that continued climate change will trigger a major redistribution in growth responses to climate.
Abstract: Energy and water limitations of tree growth remain insufficiently understood at large spatiotemporal scales, hindering model representation of interannual or longer-term ecosystem processes. By assessing and statistically scaling the climatic drivers from 2710 tree-ring sites, we identified the boreal and temperate land areas where tree growth during 1930–1960 CE responded positively to temperature (20.8 ± 3.7 Mio km2; 25.9 ± 4.6%), precipitation (77.5 ± 3.3 Mio km2; 96.4 ± 4.1%), and other parameters. The spatial manifestation of this climate response is determined by latitudinal and altitudinal temperature gradients, indicating that warming leads to geographic shifts in growth limitations. We observed a significant (P
251 citations
Henan University1, Hebei University2, Chinese Academy of Sciences3, Peking University4, Colorado State University5, University of Vermont6, University of Antwerp7, University of Tasmania8, Auckland University of Technology9, University of Copenhagen10, Swedish University of Agricultural Sciences11, East China Normal University12, Northern Arizona University13, Villanova University14, ETH Zurich15, University of Bern16, Purdue University17, Marine Biological Laboratory18, Michigan State University19, Iowa State University20, Environmental Molecular Sciences Laboratory21, Lawrence Berkeley National Laboratory22, University of California, Berkeley23, United States Department of Agriculture24, Boston University25, Virginia Tech26, Oak Ridge National Laboratory27, Indiana University28, Commonwealth Scientific and Industrial Research Organisation29, Binzhou University30
TL;DR: There is an urgent need to explore the interactions among multiple global change drivers in underrepresented regions such as semi-arid ecosystems, forests in the tropics and subtropics, and Arctic tundra when forecasting future terrestrial carbon-climate feedback.
Abstract: Direct quantification of terrestrial biosphere responses to global change is crucial for projections of future climate change in Earth system models. Here, we synthesized ecosystem carbon-cycling data from 1,119 experiments performed over the past four decades concerning changes in temperature, precipitation, CO2 and nitrogen across major terrestrial vegetation types of the world. Most experiments manipulated single rather than multiple global change drivers in temperate ecosystems of the USA, Europe and China. The magnitudes of warming and elevated CO2 treatments were consistent with the ranges of future projections, whereas those of precipitation changes and nitrogen inputs often exceeded the projected ranges. Increases in global change drivers consistently accelerated, but decreased precipitation slowed down carbon-cycle processes. Nonlinear (including synergistic and antagonistic) effects among global change drivers were rare. Belowground carbon allocation responded negatively to increased precipitation and nitrogen addition and positively to decreased precipitation and elevated CO2. The sensitivities of carbon variables to multiple global change drivers depended on the background climate and ecosystem condition, suggesting that Earth system models should be evaluated using site-specific conditions for best uses of this large dataset. Together, this synthesis underscores an urgent need to explore the interactions among multiple global change drivers in underrepresented regions such as semi-arid ecosystems, forests in the tropics and subtropics, and Arctic tundra when forecasting future terrestrial carbon-climate feedback.
245 citations
University of Würzburg1, National University of Comahue2, Spanish National Research Council3, Swedish University of Agricultural Sciences4, Universidade Federal de Goiás5, University of Lisbon6, Stanford University7, Commonwealth Scientific and Industrial Research Organisation8, National University of Río Negro9, ETH Zurich10, Cornell University11, University of California, Davis12, The Nature Conservancy13, Wageningen University and Research Centre14, University of British Columbia15, Great Lakes Bioenergy Research Center16, University of California, Berkeley17, University of Padua18, University of New England (United States)19, Lund University20, University of Göttingen21, University of La Rochelle22, Institut national de la recherche agronomique23, Federal University of Ceará24, Concordia University Wisconsin25, University of Belgrade26, National University of Tucumán27, Michigan State University28, University of Brasília29, University of Greenwich30, University of Reading31, University of Wisconsin-Madison32, Boise State University33, University of Texas at Austin34, University of Haifa35, Kansas State University36, University of Freiburg37, University of Hamburg38, University of California, Santa Barbara39, Seattle University40, University of Vienna41, University of Florida42, Centro Agronómico Tropical de Investigación y Enseñanza43, National Audubon Society44, University of Buenos Aires45, Virginia Tech46, University of Bordeaux47, University of Auckland48, University College Dublin49, Trinity College, Dublin50, University of Tokyo51, Federal University of Bahia52, Lincoln University (Pennsylvania)53, National Institute for Environmental Studies54, International Food Policy Research Institute55, Xi'an Jiaotong-Liverpool University56
TL;DR: Using a global database from 89 crop systems, the relative importance of abundance and species richness for pollination, biological pest control and final yields in the context of on-going land-use change is partitioned.
Abstract: Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by few abundant species or rely on high richness remains unclear. Using a global database from 89 crop systems, we partition the relative importance of abundance and species richness for pollination, biological pest control and final yields in the context of on-going land-use change. Pollinator and enemy richness directly supported ecosystem services independent of abundance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society.
TL;DR: In this article, a comprehensive assessment of water-related ecosystem services and to improve understanding of how they are impacted by land use and climate change in Kentucky, USA is presented, using InVEST models and environmental setting scenarios.
University of New Hampshire1, Université Paris-Saclay2, SupAgro3, Polytechnic University of Valencia4, University of Idaho5, University of Technology, Sydney6, Chiba University7, Chinese Academy of Sciences8, University of Texas at Austin9, University of Maryland, College Park10, Sun Yat-sen University11, South Dakota State University12
TL;DR: A review of the advances in remote sensing of the terrestrial carbon cycle from the early 1970s to present can be found in this paper, where the authors provide a comprehensive and insightful review.
Leipzig University1, Martin Luther University of Halle-Wittenberg2, Universidade Positivo3, University of Vigo4, Empresa Brasileira de Pesquisa Agropecuária5, ETH Zurich6, Moscow State University7, University of Freiburg8, University of Jena9, University of Catania10, Wageningen University and Research Centre11, Free University of Berlin12, Senckenberg Museum13, Colorado State University14, National Agriculture and Food Research Organization15, University of Nairobi16, Commonwealth Scientific and Industrial Research Organisation17, National Scientific and Technical Research Council18, Brandenburg University of Technology19, Cornell University20, University College Dublin21, United States Forest Service22, University of Toronto23, Aberystwyth University24, State University of New York at Cortland25, National University of Luján26, University of Trier27, University of the Philippines Mindanao28, Razi University29, Josip Juraj Strossmayer University of Osijek30, Kyushu University31, Minnesota Pollution Control Agency32, Aarhus University33, Northern Kentucky University34, Lincoln University (Missouri)35, University of Agricultural Sciences, Dharwad36, Fukushima University37, Matej Bel University38, Lancaster University39, Université d'Abobo-Adjamé40, Tarbiat Modares University41, Pachhunga University College42, University of São Paulo43, University of Hawaii at Hilo44, College of Tropical Agriculture and Human Resources45, Oklahoma State University–Stillwater46, Forest Research Institute47, University of Extremadura48, Katholieke Universiteit Leuven49, Research Institute for Nature and Forest50, Natural Resources Institute Finland51, University of Alcalá52, COMSATS Institute of Information Technology53, King Abdulaziz University54, University of Minnesota55, Federal University of Maranhão56, Jagiellonian University57, Technical University of Berlin58, University of Wisconsin-Madison59, Leibniz Association60, Braunschweig University of Technology61, University of Innsbruck62, Russian Academy of Sciences63, Keldysh Institute of Applied Mathematics64, Khalsa College, Amritsar65, University of La Laguna66, Kōchi University67, Universidad Pública de Navarra68, McGill University69, The Nature Conservancy70, University of Giessen71, Henan University72, University of Saint Mary73
TL;DR: It was found that local species richness and abundance typically peaked at higher latitudes, displaying patterns opposite to those observed in aboveground organisms, which suggest that climate change may have serious implications for earthworm communities and for the functions they provide.
Abstract: Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, and biomass. We found that local species richness and abundance typically peaked at higher latitudes, displaying patterns opposite to those observed in aboveground organisms. However, high species dissimilarity across tropical locations may cause diversity across the entirety of the tropics to be higher than elsewhere. Climate variables were found to be more important in shaping earthworm communities than soil properties or habitat cover. These findings suggest that climate change may have serious implications for earthworm communities and for the functions they provide.
TL;DR: This study analyzed the impacts of urbanization on ecosystem services from 2000 to 2010 in the Beijing-Tianjin-Hebei (BTH) urban megaregion in China and found both ecosystem services and urbanization level in the BTH region increased.
26 Feb 2019
TL;DR: The importance of salinity in soil microbial community composition and assembly processes in a desert ecosystem is suggested by a null modeling approach to estimate microbial community assembly processes along a salinity gradient, which found that salinity imposed a strong selection pressure on the microbial community, which resulted in a dominance of deterministic processes.
Abstract: Soil salinization is a growing environmental problem caused by both natural and human activities. Excessive salinity in soil suppresses growth, decreases species diversity, and alters the community composition of plants; however, the effect of salinity on soil microbial communities is poorly understood. Here, we characterize the soil microbial community along a natural salinity gradient in Gurbantunggut Desert, Northwestern China. Microbial diversity linearly decreased with increases in salinity, and community dissimilarity significantly increased with salinity differences. Soil salinity showed a strong effect on microbial community dissimilarity, even after controlling for the effects of spatial distance and other environmental variables. Microbial phylotypes (n = 270) belonging to Halobacteria, Nitriliruptoria, [Rhodothermi], Gammaproteobacteria, and Alphaproteobacteria showed a high-salinity niche preference. Out of nine potential phenotypes predicted by BugBase, oxygen-related phenotypes showed a significant relationship with salinity content. To explore the community assembly processes, we used null models of within-community (nearest-taxon index [NTI]) and between-community (βNTI) phylogenetic composition. NTI showed a significantly negative relationship with salinity, suggesting that the microbial community was less phylogenetically clustered in more-saline soils. βNTI, the between-community analogue of NTI, showed that deterministic processes have overtaken stochastic processes across all sites, suggesting the importance of environmental filtering in microbial community assembly. Taken together, these results suggest the importance of salinity in soil microbial community composition and assembly processes in a desert ecosystem. IMPORTANCE Belowground microorganisms are indispensable components for nutrient cycling in desert ecosystems, and understanding how they respond to increased salinity is essential for managing and ameliorating salinization. Our sequence-based data revealed that microbial diversity decreased with increasing salinity, and certain salt-tolerant phylotypes and phenotypes showed a positive relationship with salinity. Using a null modeling approach to estimate microbial community assembly processes along a salinity gradient, we found that salinity imposed a strong selection pressure on the microbial community, which resulted in a dominance of deterministic processes. Studying microbial diversity and community assembly processes along salinity gradients is essential in understanding the fundamental ecological processes in desert ecosystems affected by salinization.
TL;DR: Some coastal ecosystems (mangroves, tidal marshes and seagrass) are established Blue Carbon ecosystems as they often have high carbon stocks, support long-term carbon storage, offer the potential to manage greenhouse gas emissions and support other adaptation policies.
Abstract: Blue Carbon is a term coined in 2009 to draw attention to the degradation of marine and coastal ecosystems and the need to conserve and restore them to mitigate climate change and for the other ecosystem services they provide. Blue Carbon has multiple meanings, which we aim to clarify here, which reflect the original descriptions of the concept including (1) all organic matter captured by marine organisms, and (2) how marine ecosystems could be managed to reduce greenhouse gas emissions and thereby contribute to climate change mitigation and conservation. The multifaceted nature of the Blue Carbon concept has led to unprecedented collaboration across disciplines, where scientists, conservationists and policy makers have interacted intensely to advance shared goals. Some coastal ecosystems (mangroves, tidal marshes and seagrass) are established Blue Carbon ecosystems as they often have high carbon stocks, support long-term carbon storage, offer the potential to manage greenhouse gas emissions and support other adaptation policies. Some marine ecosystems do not meet key criteria for inclusion within the Blue Carbon framework (e.g. fish, bivalves and coral reefs). Others have gaps in scientific understanding of carbon stocks or greenhouse gas fluxes, or currently there is limited potential for management or accounting for carbon sequestration (macroalgae and phytoplankton), but may be considered Blue Carbon ecosystems in the future, once these gaps are addressed.
TL;DR: In this paper, a quantitative analysis of historical changes in land use/land cover in the context of the urban land sprawl was conducted to better understand existing relationships between ecological services and land use and land cover change.
TL;DR: This work makes a number of predictions concerning climate change effects on PSFs and consequences for vegetation-soil-climate feedbacks while acknowledging that they may be context-dependent, spatially heterogeneous, and temporally variable.
Abstract: Plant-soil feedbacks (PSFs) are interactions among plants, soil organisms, and abiotic soil conditions that influence plant performance, plant species diversity, and community structure, ultimately driving ecosystem processes. We review how climate change will alter PSFs and their potential consequences for ecosystem functioning. Climate change influences PSFs through the performance of interacting species and altered community composition resulting from changes in species distributions. Climate change thus affects plant inputs into the soil subsystem via litter and rhizodeposits and alters the composition of the living plant roots with which mutualistic symbionts, decomposers, and their natural enemies interact. Many of these plant-soil interactions are species-specific and are greatly affected by temperature, moisture, and other climate-related factors. We make a number of predictions concerning climate change effects on PSFs and consequences for vegetation-soil-climate feedbacks while acknowledging that they may be context-dependent, spatially heterogeneous, and temporally variable.
TL;DR: This work has suggested that the establishment of non-native organisms in both terrestrial and marine ecosystems may present an even greater threat than climate change itself.
Abstract: Antarctica and the surrounding Southern Ocean are facing complex environmental change. Their native biota has adapted to the region's extreme conditions over many millions of years. This unique biota is now challenged by environmental change and the direct impacts of human activity. The terrestrial biota is characterized by considerable physiological and ecological flexibility and is expected to show increases in productivity, population sizes and ranges of individual species, and community complexity. However, the establishment of non-native organisms in both terrestrial and marine ecosystems may present an even greater threat than climate change itself. In the marine environment, much more limited response flexibility means that even small levels of warming are threatening. Changing sea ice has large impacts on ecosystem processes, while ocean acidification and coastal freshening are expected to have major impacts.
TL;DR: A systematic review of studies on Biodiversity and Ecosystem Functioning revealed that in many cases, biodiversity promotes average biomass production and its temporal stability, and pollination success, and factors other than biodiversity can be even more important in driving ecosystem functioning.
Abstract: Approximately 25 years ago, ecologists became increasingly interested in the question of whether ongoing biodiversity loss matters for the functioning of ecosystems. As such, a new ecological subfield on Biodiversity and Ecosystem Functioning (BEF) was born. This subfield was initially dominated by theoretical studies and by experiments in which biodiversity was manipulated, and responses of ecosystem functions such as biomass production, decomposition rates, carbon sequestration, trophic interactions and pollination were assessed. More recently, an increasing number of studies have investigated BEF relationships in non-manipulated ecosystems, but reviews synthesizing our knowledge on the importance of real-world biodiversity are still largely missing. I performed a systematic review in order to assess how biodiversity drives ecosystem functioning in both terrestrial and aquatic, naturally assembled communities, and on how important biodiversity is compared to other factors, including other aspects of community composition and abiotic conditions. The outcomes of 258 published studies, which reported 726 BEF relationships, revealed that in many cases, biodiversity promotes average biomass production and its temporal stability, and pollination success. For decomposition rates and ecosystem multifunctionality, positive effects of biodiversity outnumbered negative effects, but neutral relationships were even more common. Similarly, negative effects of prey biodiversity on pathogen and herbivore damage outnumbered positive effects, but were less common than neutral relationships. Finally, there was no evidence that biodiversity is related to soil carbon storage. Most BEF studies focused on the effects of taxonomic diversity, however, metrics of functional diversity were generally stronger predictors of ecosystem functioning. Furthermore, in most studies, abiotic factors and functional composition (e.g. the presence of a certain functional group) were stronger drivers of ecosystem functioning than biodiversity per se. While experiments suggest that positive biodiversity effects become stronger at larger spatial scales, in naturally assembled communities this idea is too poorly studied to draw general conclusions. In summary, a high biodiversity in naturally assembled communities positively drives various ecosystem functions. At the same time, the strength and direction of these effects vary highly among studies, and factors other than biodiversity can be even more important in driving ecosystem functioning. Thus, to promote those ecosystem functions that underpin human well-being, conservation should not only promote biodiversity per se, but also the abiotic conditions favouring species with suitable trait combinations.
TL;DR: It is found that plant diversity increases microbial biomass and respiration rates, an effect moderated by stand age, which underlines strong relationships between plant diversity and soil microorganisms across global terrestrial ecosystems and suggests the importance of plant diversity in maintaining belowground ecosystem functioning.
Abstract: Soil microorganisms are key to biological diversity and many ecosystem processes in terrestrial ecosystems. Despite the current alarming loss of plant diversity, it is unclear how plant species diversity affects soil microorganisms. By conducting a global meta-analysis with paired observations of plant mixtures and monocultures from 106 studies, we show that microbial biomass, bacterial biomass, fungal biomass, fungi:bacteria ratio, and microbial respiration increase, while Gram-positive to Gram-negative bacteria ratio decrease in response to plant mixtures. The increases in microbial biomass and respiration are more pronounced in older and more diverse mixtures. The effects of plant mixtures on all microbial attributes are consistent across ecosystem types including natural forests, planted forests, planted grasslands, croplands, and planted containers. Our study underlines strong relationships between plant diversity and soil microorganisms across global terrestrial ecosystems and suggests the importance of plant diversity in maintaining belowground ecosystem functioning.
TL;DR: A generalized nitrogen budget for a C3 leaf cell is provided and the potential for improving photosynthesis from a nitrogen perspective is discussed.
Abstract: Global food security depends on three main cereal crops (wheat, rice and maize) achieving and maintaining high yields, as well as increasing their future yields. Fundamental to the production of this biomass is photosynthesis. The process of photosynthesis involves a large number of proteins that together account for the majority of the nitrogen in leaves. As large amounts of nitrogen are removed in the harvested grain, this needs to be replaced either from synthetic fertilizer or biological nitrogen fixation. Knowledge about photosynthetic properties of leaves in natural ecosystems is also important, particularly when we consider the potential impacts of climate change. While the relationship between nitrogen and photosynthetic capacity of a leaf differs between species, leaf nitrogen content provides a useful way to incorporate photosynthesis into models of ecosystems and the terrestrial biosphere. This review provides a generalized nitrogen budget for a C3 leaf cell and discusses the potential for improving photosynthesis from a nitrogen perspective.
TL;DR: It is shown that diversifying livestock could promote grassland biodiversity and ecosystem multifunctionality in an increasingly managed world, and insights are provided into the importance of multitrophic diversity to maintain multidiversity in managed ecosystems.
Abstract: Increasing plant diversity can increase ecosystem functioning, stability, and services in both natural and managed grasslands, but the effects of herbivore diversity, and especially of livestock diversity, remain underexplored. Given that managed grazing is the most extensive land use worldwide, and that land managers can readily change livestock diversity, we experimentally tested how livestock diversification (sheep, cattle, or both) influenced multidiversity (the diversity of plants, insects, soil microbes, and nematodes) and ecosystem multifunctionality (including plant biomass production, plant leaf N and P, above-ground insect abundance, nutrient cycling, soil C stocks, water regulation, and plant-microbe symbiosis) in the world's largest remaining grassland. We also considered the potential dependence of ecosystem multifunctionality on multidiversity. We found that livestock diversification substantially increased ecosystem multifunctionality by increasing multidiversity. The link between multidiversity and ecosystem multifunctionality was always stronger than the link between single diversity components and functions. Our work provides insights into the importance of multitrophic diversity to maintain multifunctionality in managed ecosystems and suggests that diversifying livestock could promote both multidiversity and ecosystem multifunctionality in an increasingly managed world.
TL;DR: Mapping landscape-level heterogeneity of microclimate advances ability to study how organisms respond to climate variation, which has important implications for understanding climate-change impacts on biodiversity and ecosystems.
Abstract: Microclimates at the land-air interface affect the physiological functioning of organisms which, in turn, influences the structure, composition, and functioning of ecosystems. We review how remote sensing technologies that deliver detailed data about the structure and thermal composition of environments are improving the assessment of microclimate over space and time. Mapping landscape-level heterogeneity of microclimate advances our ability to study how organisms respond to climate variation, which has important implications for understanding climate-change impacts on biodiversity and ecosystems. Interpolating in situ microclimate measurements and downscaling macroclimate provides an organism-centered perspective for studying climate-species interactions and species distribution dynamics. We envisage that mapping of microclimate will soon become commonplace, enabling more reliable predictions of species and ecosystem responses to global change.
TL;DR: The challenges and opportunities that vent ecosystems provide for microbial life and their relationship to biogeography are explored, including their relationships with underlying geology and hydrothermal geochemistry.
Abstract: The discovery of chemosynthetic ecosystems at deep-sea hydrothermal vents in 1977 changed our view of biology. Chemosynthetic bacteria and archaea form the foundation of vent ecosystems by exploiting the chemical disequilibrium between reducing hydrothermal fluids and oxidizing seawater, harnessing this energy to fix inorganic carbon into biomass. Recent research has uncovered fundamental aspects of these microbial communities, including their relationships with underlying geology and hydrothermal geochemistry, interactions with animals via symbiosis and distribution both locally in various habitats within vent fields and globally across hydrothermal systems in diverse settings. Although ‘black smokers’ and symbioses between microorganisms and macrofauna attract much attention owing to their novelty and the insights they provide into life under extreme conditions, habitats such as regions of diffuse flow, subseafloor aquifers and hydrothermal plumes have important roles in the global cycling of elements through hydrothermal systems. Owing to sharp contrasts in physical and chemical conditions between these various habitats and their dynamic, extreme and geographically isolated nature, hydrothermal vents provide a valuable window into the environmental and ecological forces that shape microbial communities and insights into the limits, origins and evolution of microbial life. Hydrothermal vents are unique habitats for chemosynthetic bacteria and archaea and the animals that live in symbiosis with them. In this Review, Dick explores the challenges and opportunities that vent ecosystems provide for microbial life and their relationship to biogeography.
University of Marburg1, University of Bayreuth2, University of Greifswald3, Lund University4, Lanzhou University5, University of Göttingen6, Montana State University7, University of Cambridge8, Leibniz University of Hanover9, Senckenberg Museum10, University of Innsbruck11, China University of Geosciences (Wuhan)12, Chinese Academy of Sciences13, American Museum of Natural History14, Royal Botanic Garden Edinburgh15, University of Rostock16, University of Kiel17, Karlsruhe Institute of Technology18, Dresden University of Technology19
TL;DR: Traditional migratory rangeland management was sustainable over millennia, and possibly still offers the best strategy to conserve and possibly increase C stocks in the Kobresia turf.
TL;DR: A number of marine top predator species have been proposed as sentinel species to provide information about unobserved components of the ecosystem (Zacharias and Roff 2001).
Abstract: I an era of unprecedented environmental change, developing a suite of tools for ecosystem monitoring is critical. This need is particularly urgent in marine ecosystems, given the rapid, climatedriven changes in marine populations and communities (Poloczanska et al. 2013). Comprehensive monitoring in marine ecosystems presents a challenge due to difficulties inherent in observing the highly dynamic ocean environment at relevant timescales. Traditional shipbased surveys are expensive, autonomous floats and underwater vehicles are still sparsely distributed, and remote sensing fails to capture threedimensional ocean structure. Furthermore, ecological monitoring in the open ocean is largely extractive and often involves lethal sampling of animal communities. In the undersampled marine realm, innovative and costeffective tools that can rapidly assess ecosystem responses to environmental change are vital. “Sentinel” species have been proposed as a means to provide information about unobserved components of the ecosystem (Zacharias and Roff 2001). Classic examples of sentinels include a domesticated variety of the canary (Serinus canaria), which was formerly used to monitor air quality in coal mines, and invertebrates, whose diversity has been used as an indicator of aquatic ecosystem health (Wilhm and Dorris 1968; Barry 2013). More recent studies show that vertebrate species can serve as sentinels of human health and environmental pollution (Bossart 2006; Smits and Fernie 2013), as well as coupled climate–ecosystem processes (Moore 2008). Useful sentinel species should integrate broader processes into rapidly interpretable metrics that reflect underlying ecosystem processes. Marine top predators (including certain species of predatory fish, seabirds, sea turtles, and marine mammals) have been proposed as ecosystem sentinels based on their conspicuous nature and capacity to indicate or respond to changes in ecosystem structure and function that would otherwise be difficult to observe directly (Figure 1; Bossart 2006; Boersma 2008; Moore 2008). Many marine top predators possess key characteristics of sentinel species, including (1) exhibiting clear responses to environmental variability or change (Sydeman et al. 2015; Fleming et al. 2016), (2) playing important roles in shaping marine food webs (Estes et al. 2016), and (3) indicating anthropogenic impacts on ecosystems (Sergio et al. 2008). Given these characteristics, there is a strong argument for using marine predators as ecosystem sentinels. Despite the contemporary use of marine predators as sentinels (relevant examples are listed in WebTable 1), the absence of a standardized framework for identifying sentinel Marine top predators as climate and ecosystem sentinels
TL;DR: In this article, the authors discussed how the climate change influences soil microbial communities and plant-microbe interactions and highlighted the role of metagenomics for unlocking the soil microbial black box.
Abstract: Maintenance of soil health is central to agricultural sustainability and a key factor that reflects the productivity of agro ecosystems. However, at present the soil resources are under severe threats from various anthropogenic activities including climate change. Climate changes add more uncertainties and complexities to agriculture, ecosystem and intimidate their sustainability. Plant-associated microbial communities stimulate the plant growth and increase their resistance to various abiotic and biotic stresses. Linking the distribution of microbial diversity and ecosystem functioning is essential to understand ecosystem responses to changing environment. Soil microbial taxa are imperative in relation to global climate changes as they play important and undisputable roles in biogeochemical cycling, plant growth and carbon sequestration. Modern genomic approaches show tremendous potential for identification of uncultivated diversity and finding shifts in the bacterial community associated with sensitive and disease tolerant plants, and understanding how microbes are affected by climate change. In this review, we discussed how the climate change influences soil microbial communities and plant–microbe interactions. Further, in this review the we have highlighted the role of metagenomics for unlocking the soil microbial black box.
TL;DR: In the last three decades, over 4.1 million hectares have burned in Arizona and New Mexico and the largest fires in documented history have occurred in the past two decades as discussed by the authors.