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1
Novák, Viliam. „Ecosystems and Global Changes“. Acta Horticulturae et Regiotecturae 24, s1 (01.05.2021): 70–79. http://dx.doi.org/10.2478/ahr-2021-0012.
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Abstract Increasing population has led to the increasing demand for food, raw materials, and energy. Continuing land use changes, intensification of its exploitation, deforestation, fossil fuel combustion, and related carbon dioxide production have been contributing to change of water and energy balance of the globe, thus changing conditions for life. Other reasons for changing conditions on the Earth are natural changes in interactions between the Earth and outer space. Actual climate change is a part of other global changes resulting in both natural and anthropogenic changes. It is mostly felt as a change of global temperature and increase of precipitation intensities and totals. Flood periods are followed by long periods without precipitations. Increasing population as well as increasing consumption of resources lead to the increasing imbalance between our planet production and consumption. To preserve good conditions for population of the Earth, it is necessary to decrease consumption of energy, raw materials, and food to reach equilibrium between Earth´s ecosystem production and consumption of the ecosystem products.
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Link, Jason S., und Reg A. Watson. „Global ecosystem overfishing: Clear delineation within real limits to production“. Science Advances 5, Nr. 6 (Juni 2019): eaav0474. http://dx.doi.org/10.1126/sciadv.aav0474.
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The well-documented value of marine fisheries is threatened by overfishing. Management typically focuses on target populations but lacks effective tools to document or restrain overexploitation of marine ecosystems. Here, we present three indices and accompanying thresholds to detect and delineate ecosystem overfishing (EOF): the Fogarty, Friedland, and Ryther indices. These are based on widely available and readily interpreted catch and satellite data that link fisheries landings to primary production using known limits of trophic transfer efficiency. We propose theoretically and empirically based thresholds for each of those indices; with these criteria, several ecosystems are fished sustainably, but nearly 40 to 50% of tropical and temperate ecosystems exceed even extreme thresholds. Applying these criteria to global fisheries data results in strong evidence for two specific instances of EOF, increases in both pressure on tropical fish and a climate-mediated polar shift. Here, we show that these two patterns represent evidence for global EOF.
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Vedrova, Estella F., Fedor I. Pleshikov und Vladimir Ya Kaplunov. „Net Ecosystem Production of Boreal Larch Ecosystems on the Yenisei Transect“. Mitigation and Adaptation Strategies for Global Change 11, Nr. 1 (Januar 2006): 173–90. http://dx.doi.org/10.1007/s11027-006-1016-4.
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Alongi, Daniel M. „Carbon Balance in Salt Marsh and Mangrove Ecosystems: A Global Synthesis“. Journal of Marine Science and Engineering 8, Nr. 10 (30.09.2020): 767. http://dx.doi.org/10.3390/jmse8100767.
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Mangroves and salt marshes are among the most productive ecosystems in the global coastal ocean. Mangroves store more carbon (739 Mg CORG ha−1) than salt marshes (334 Mg CORG ha−1), but the latter sequester proportionally more (24%) net primary production (NPP) than mangroves (12%). Mangroves exhibit greater rates of gross primary production (GPP), aboveground net primary production (AGNPP) and plant respiration (RC), with higher PGPP/RC ratios, but salt marshes exhibit greater rates of below-ground NPP (BGNPP). Mangroves have greater rates of subsurface DIC production and, unlike salt marshes, exhibit active microbial decomposition to a soil depth of 1 m. Salt marshes release more CH4 from soil and creek waters and export more dissolved CH4, but mangroves release more CO2 from tidal waters and export greater amounts of particulate organic carbon (POC), dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC), to adjacent waters. Both ecosystems contribute only a small proportion of GPP, RE (ecosystem respiration) and NEP (net ecosystem production) to the global coastal ocean due to their small global area, but contribute 72% of air–sea CO2 exchange of the world’s wetlands and estuaries and contribute 34% of DIC export and 17% of DOC + POC export to the world’s coastal ocean. Thus, both wetland ecosystems contribute disproportionately to carbon flow of the global coastal ocean.
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Woodson, C. Brock, und Steven Y. Litvin. „Ocean fronts drive marine fishery production and biogeochemical cycling“. Proceedings of the National Academy of Sciences 112, Nr. 6 (26.01.2015): 1710–15. http://dx.doi.org/10.1073/pnas.1417143112.
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Long-term changes in nutrient supply and primary production reportedly foreshadow substantial declines in global marine fishery production. These declines combined with current overfishing, habitat degradation, and pollution paint a grim picture for the future of marine fisheries and ecosystems. However, current models forecasting such declines do not account for the effects of ocean fronts as biogeochemical hotspots. Here we apply a fundamental technique from fluid dynamics to an ecosystem model to show how fronts increase total ecosystem biomass, explain fishery production, cause regime shifts, and contribute significantly to global biogeochemical budgets by channeling nutrients through alternate trophic pathways. We then illustrate how ocean fronts affect fishery abundance and yield, using long-term records of anchovy–sardine regimes and salmon abundances in the California Current. These results elucidate the fundamental importance of biophysical coupling as a driver of bottom–up vs. top–down regulation and high productivity in marine ecosystems.
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Liao, Chang, und Qianlai Zhuang. „Reduction of Global Plant Production due to Droughts from 2001 to 2010: An Analysis with a Process-Based Global Terrestrial Ecosystem Model“. Earth Interactions 19, Nr. 16 (01.12.2015): 1–21. http://dx.doi.org/10.1175/ei-d-14-0030.1.
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Abstract Droughts dramatically affect plant production of global terrestrial ecosystems. To date, quantification of this impact remains a challenge because of the complex plant physiological and biochemical processes associated with drought. Here, this study incorporates a drought index into an existing process-based terrestrial ecosystem model to estimate the drought impact on global plant production for the period 2001–10. Global Moderate Resolution Imaging Spectroradiometer (MODIS) gross primary production (GPP) data products are used to constrain model parameters and verify the model algorithms. The verified model is then applied to evaluate the drought impact. The study indicates that droughts will reduce GPP by 9.8 g C m−2 month−1 during the study period. On average, drought reduces GPP by 10% globally. As a result, the global GPP decreased from 106.4 to 95.9 Pg C yr−1 while the global net primary production (NPP) decreased from 54.9 to 49.9 Pg C yr−1. This study revises the estimation of the global NPP and suggests that the future quantification of the global carbon budget of terrestrial ecosystems should take the drought impact into account.
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Hall, Robert, Jennifer Tank, Michelle Baker, Emma Rosi-Marshall, Michael Grace und Erin Hotchkiss. „High Rates of Ecosytem Metabolism in Five Western Rivers“. UW National Parks Service Research Station Annual Reports 33 (01.01.2011): 115–18. http://dx.doi.org/10.13001/uwnpsrc.2011.3799.
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Primary production and respiration are core functions of river ecosystems that in part determine the carbon balance. Gross primary production (GPP) is the total rate of carbon fixation by autotrophs such as algae and higher plants and is equivalent to photosynthesis. Ecosystem respiration (ER) measures rate at which organic carbon is mineralized to CO2 by all organisms in an ecosystem. Together these fluxes can indicate the base of the food web to support animal production (Marcarelli et al. 2011), can predict the cycling of other elements (Hall and Tank 2003), and can link ecosystems to global carbon cycling (Cole et al. 2007).
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Zak, Donald R., Kurt S. Pregitzer und George E. Host. „Landscape variation in nitrogen mineralization and nitrification“. Canadian Journal of Forest Research 16, Nr. 6 (01.12.1986): 1258–63. http://dx.doi.org/10.1139/x86-223.
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Potential nitrogen mineralization and nitrification were studied in three upland forest ecosystems to develop an understanding of nitrogen turnover on a landscape basis. The northern Michigan forests studied were an oak ecosystem primarily associated with glacial outwash features and two sugar maple ecosystems that occurred on morainal landforms but differed in the diversity and abundance of ground flora species. Four randomly chosen stands separated by at least 6 km were sampled within each of the three ecosystems. Potential net nitrogen mineralization and nitrification were determined by an aerobic laboratory incubation. Litter was collected from all ecosystems during autumn. Litter production, nitrogen returned to the forest floor, and net mineralization differed by a factor of two between the oak and sugar maple ecosystems. The species-rich sugar maple ecosystems exhibited a fourfold increase in potential nitrification compared with the species-poor sugar maple ecosystem. Nitrification was virtually absent in the oak ecosystem. The distribution of ecosystems could be used to predict differences in potential mineralization and nitrification. Areas susceptible to nitrate loss following intensive forest management practices may be related to the occurrence of plant associations. In this upland landscape, high nitrification potentials appear to be confined to species-rich sugar maple forests.
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Spahni, R., R. Wania, L. Neef, M. van Weele, I. Pison, P. Bousquet, C. Frankenberg et al. „Constraining global methane emissions and uptake by ecosystems“. Biogeosciences Discussions 8, Nr. 1 (11.01.2011): 221–72. http://dx.doi.org/10.5194/bgd-8-221-2011.
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Abstract. Natural methane (CH4) emissions from wet ecosystems are an important part of today's global CH4 budget. Climate affects the exchange of CH4 between ecosystems and the atmosphere by influencing CH4 production, oxidation, and transport in the soil. The net CH4 exchange depends on ecosystem hydrology, soil and vegetation characteristics. Here, the LPJ-WHyMe global dynamical vegetation model is used to simulate global net CH4 emissions for different ecosystems: northern peatlands (45°–90° N), naturally inundated wetlands (60° S–45° N), rice agriculture and wet mineral soils. Mineral soils are a potential CH4 sink, but can also be a source with the direction of the net exchange depending on soil moisture content. The geographical and seasonal distributions are evaluated against multi-dimensional atmospheric inversions for 2003–2005, using two independent four-dimensional variational assimilation systems. The atmospheric inversions are constrained by the atmospheric CH4 observations of the SCIAMACHY satellite instrument and global surface networks. Compared to LPJ-WHyMe the inversions result in a significant reduction in the emissions from northern peatlands and suggest that LPJ-WHyMe maximum annual emissions peak about one month late. The inversions do not put strong constraints on the division of sources between inundated wetlands and wet mineral soils in the tropics. Based on the inversion results we adapt model parameters in LPJ-WHyMe and simulate the surface exchange of CH4 over the period 1990–2008. Over the whole period we infer an increase of global ecosystem CH4 emissions of +1.11 Tg CH4 yr−1, not considering potential additional changes in wetland extent. The increase in simulated CH4 emissions is attributed to enhanced soil respiration resulting from the observed rise in land temperature and in atmospheric carbon dioxide that were used as input. The long-term decline of the atmospheric CH4 growth rate from 1990 to 2006 cannot be fully explained with the simulated ecosystem emissions. However, these emissions show an increasing trend of +3.62 Tg CH4 yr−1 over 2005–2008 which can partly explain the renewed increase in atmospheric CH4 concentration during recent years.
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Spahni, R., R. Wania, L. Neef, M. van Weele, I. Pison, P. Bousquet, C. Frankenberg et al. „Constraining global methane emissions and uptake by ecosystems“. Biogeosciences 8, Nr. 6 (23.06.2011): 1643–65. http://dx.doi.org/10.5194/bg-8-1643-2011.
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Abstract. Natural methane (CH4) emissions from wet ecosystems are an important part of today's global CH4 budget. Climate affects the exchange of CH4 between ecosystems and the atmosphere by influencing CH4 production, oxidation, and transport in the soil. The net CH4 exchange depends on ecosystem hydrology, soil and vegetation characteristics. Here, the LPJ-WHyMe global dynamical vegetation model is used to simulate global net CH4 emissions for different ecosystems: northern peatlands (45°–90° N), naturally inundated wetlands (60° S–45° N), rice agriculture and wet mineral soils. Mineral soils are a potential CH4 sink, but can also be a source with the direction of the net exchange depending on soil moisture content. The geographical and seasonal distributions are evaluated against multi-dimensional atmospheric inversions for 2003–2005, using two independent four-dimensional variational assimilation systems. The atmospheric inversions are constrained by the atmospheric CH4 observations of the SCIAMACHY satellite instrument and global surface networks. Compared to LPJ-WHyMe the inversions result in a~significant reduction in the emissions from northern peatlands and suggest that LPJ-WHyMe maximum annual emissions peak about one month late. The inversions do not put strong constraints on the division of sources between inundated wetlands and wet mineral soils in the tropics. Based on the inversion results we diagnose model parameters in LPJ-WHyMe and simulate the surface exchange of CH4 over the period 1990–2008. Over the whole period we infer an increase of global ecosystem CH4 emissions of +1.11 Tg CH4 yr−1, not considering potential additional changes in wetland extent. The increase in simulated CH4 emissions is attributed to enhanced soil respiration resulting from the observed rise in land temperature and in atmospheric carbon dioxide that were used as input. The long-term decline of the atmospheric CH4 growth rate from 1990 to 2006 cannot be fully explained with the simulated ecosystem emissions. However, these emissions show an increasing trend of +3.62 Tg CH4 yr−1 over 2005–2008 which can partly explain the renewed increase in atmospheric CH4 concentration during recent years.
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Zhu, Kai, Nona R. Chiariello, Todd Tobeck, Tadashi Fukami und Christopher B. Field. „Nonlinear, interacting responses to climate limit grassland production under global change“. Proceedings of the National Academy of Sciences 113, Nr. 38 (06.09.2016): 10589–94. http://dx.doi.org/10.1073/pnas.1606734113.
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Global changes in climate, atmospheric composition, and pollutants are altering ecosystems and the goods and services they provide. Among approaches for predicting ecosystem responses, long-term observations and manipulative experiments can be powerful approaches for resolving single-factor and interactive effects of global changes on key metrics such as net primary production (NPP). Here we combine both approaches, developing multidimensional response surfaces for NPP based on the longest-running, best-replicated, most-multifactor global-change experiment at the ecosystem scale—a 17-y study of California grassland exposed to full-factorial warming, added precipitation, elevated CO2, and nitrogen deposition. Single-factor and interactive effects were not time-dependent, enabling us to analyze each year as a separate realization of the experiment and extract NPP as a continuous function of global-change factors. We found a ridge-shaped response surface in which NPP is humped (unimodal) in response to temperature and precipitation when CO2 and nitrogen are ambient, with peak NPP rising under elevated CO2 or nitrogen but also shifting to lower temperatures. Our results suggest that future climate change will push this ecosystem away from conditions that maximize NPP, but with large year-to-year variability.
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Merrill, Amy G., und Donald R. Zak. „Factors controlling denitrification rates in upland and swamp forests“. Canadian Journal of Forest Research 22, Nr. 11 (01.11.1992): 1597–604. http://dx.doi.org/10.1139/x92-212.
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Spatial patterns of denitrification and temporal variation in the factors controlling this process were studied in three forested ecosystems in northern Lower Michigan. Two forest stands were randomly located within each of two well-drained upland forests (sugar maple–red oak/Maianthemum and sugar maple–basswood/Osmorhiza ecosystems) and one swamp ecosystem (silver maple–red maple/Osmunda ecosystem). Potential N mineralization, nitrification, and microbial respiration were measured in each forest stand using a 33-week laboratory incubation. Factors controlling denitrification were investigated in each ecosystem by treating soil samples with factorial combinations of NO3−, C, and Ar (anaerobic conditions). We also investigated the separate production of N2 and N2O during denitrification, and the factors controlling these fluxes, in a different experiment. Seasonal patterns of denitrification were quantified using an intact soil core method. Potential nitrification and microbial respiration were consistently highest in the swamp forest and lowest in the sugar maple–red oak/Maianthemum ecosystem (582 vs. 3 μg NO3−-N•g−1 and 5275 vs. 1254 μg CO2-C•g−1, respectively). Nitrate availability was the most important factor controlling denitrification in the swamp ecosystem, whereas increased soil water content resulted in the greatest response in the upland forests. Although NO3− significantly increased denitrification in the upland ecosystems, water additions elicited an even greater response. In addition, N2O production in the upland forests accounted for 70 to 90% of the total gaseous N loss; N2O accounted for only 25% of this loss in the swamp forest. Mean denitrification (intact soil cores) in the sugar maple–red oak/Maianthemum ecosystem (12 μg N2O-N•m−2•d−1) was significantly lower than rates measured in the sugar maple–bass-wood/Osmorhiza and silver maple–red maple/Osmunda ecosystems (24 and 39 μg N2O-N•m−2•d−1, respectively). Denitrification reached a maximum during June and July in the sugar maple–basswood/Osmorhiza ecosystem, whereas peaks occurred in May and September in the silver maple–red maple/Osmunda ecosystem. Denitrification in the sugar maple–red oak/Maianthemum forest was variable throughout the year and consistently low. Although variability was high, results suggest that denitrification and the factors controlling this process can be predicted using the spatial distribution of ecosystems.
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Harenda, Kamila M., Mateusz Samson, Radosław Juszczak, Krzysztof M. Markowicz, Iwona S. Stachlewska, Małgorzata Kleniewska, Alasdair MacArthur, Dirk Schüttemeyer und Bogdan H. Chojnicki. „Impact of Atmospheric Optical Properties on Net Ecosystem Productivity of Peatland in Poland“. Remote Sensing 13, Nr. 11 (28.05.2021): 2124. http://dx.doi.org/10.3390/rs13112124.
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Peatlands play an important role in the global carbon cycle due to the high carbon storage in the substrate. Ecosystem production depends, for example, on the solar energy amount that reaches the vegetation, however the diffuse component of this flux can substantially increase ecosystem net productivity. This phenomenon is observed in different ecosystems, but the study of the atmosphere optical properties on peatland production is lacking. In this paper, the presented methodology allowed us to disentangle the diffuse radiation impact on the net ecosystem production (NEP) of Rzecin peatland, Poland. It allowed us to assess the impact of the atmospheric scattering process determined by the aerosol presence in the air mass. An application of atmospheric radiation transfer (ART) and ecosystem production (EP) models showed that the increase of aerosol optical thickness from 0.09 to 0.17 caused NEP to rise by 3.4–5.7%. An increase of the diffusion index (DI) by 0.1 resulted in an NEP increase of 6.1–42.3%, while a DI decrease of 0.1 determined an NEP reduction of −49.0 to −10.5%. These results show that low peatland vegetation responds to changes in light scattering. This phenomenon should be taken into account when calculating the global CO2 uptake estimation of such ecosystems.
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Hendrick, Ronald L., und Kurt S. Pregitzer. „The dynamics of fine root length, biomass, and nitrogen content in two northern hardwood ecosystems“. Canadian Journal of Forest Research 23, Nr. 12 (01.12.1993): 2507–20. http://dx.doi.org/10.1139/x93-312.
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The dynamics of fine (<2.0 mm) roots were measured in two sugar maple (Acersaccharum Marsh.) dominated ecosystems (northern and southern sites) during 1989 and 1990 using a combination of minirhizotrons and destructive harvests of fine root biomass and N content. Greater than 50% of annual length production occurred before midsummer in both ecosystems, while the period of greatest mortality was from late summer through winter. About one third of annual fine root production and mortality occur simultaneously, with little observable change in total root length pools. Using fine root length dynamics to derive biomass production and mortality, we calculated annual biomass production values of approximately 8000 and 7300 kg•ha−1•year−1, respectively, at the southern and northern sites. Corresponding biomass mortality (i.e., turnover) values were 6700 and 4800 kg•ha−1•year−1, and total nitrogen returns to the soil from fine root mortality were 72 kg•ha−1•year−1 at the southern site and 54 kg•ha−1•year−1 at the northern site. Fine roots dominated total biomass and N litter inputs to the soil in both ecosystems, accounting for over 55% of total biomass and nearly 50% of total N returns. In both ecosystems, roots <0.5 mm comprised the bulk of fine root biomass and N pools, and the contribution of these roots to northern hardwood ecosystem carbon and nitrogen budgets may have been underestimated in the past.
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Ito, Akihiko, und Motoko Inatomi. „Water-Use Efficiency of the Terrestrial Biosphere: A Model Analysis Focusing on Interactions between the Global Carbon and Water Cycles“. Journal of Hydrometeorology 13, Nr. 2 (01.04.2012): 681–94. http://dx.doi.org/10.1175/jhm-d-10-05034.1.
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Abstract Carbon and water cycles are intimately coupled in terrestrial ecosystems, and water-use efficiency (WUE; carbon gain at the expense of unit water loss) is one of the key parameters of ecohydrology and ecosystem management. In this study, the carbon cycle and water budget of terrestrial ecosystems were simulated using a process-based ecosystem model called Vegetation Integrative Simulator for Trace Gases (VISIT), and WUE was evaluated: WUEC, defined as gross primary production (GPP) divided by transpiration; and WUES, defined as net primary production (NPP) divided by actual evapotranspiration. Total annual WUEC and WUES of the terrestrial biosphere were estimated as 8.0 and 0.92 g C kg−1 H2O, respectively, for the period 1995–2004. Spatially, WUEC and WUES were only weakly correlated. WUES ranged from <0.2 g C kg−1 H2O in arid ecosystems to >1.5 g C kg−1 H2O in boreal and alpine ecosystems. The historical simulation implied that biospheric WUE increased from 1901 to 2005 (WUEC, +7%; WUES, +12%) mainly as a result of the augmentation of productivity in parallel with the atmospheric carbon dioxide increase. Country-based analyses indicated that total NPP is largely determined by water availability, and human appropriation of NPP is also related to water resources to a considerable extent. These results have implications for 1) responses of the carbon cycle to the anticipated global hydrological changes, 2) responses of the water budget to changes in the terrestrial carbon cycle, and 3) ecosystem management based on optimized resource use.
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Kolding, Jeppe, Alida Bundy, Paul A. M. van Zwieten und Michael J. Plank. „Fisheries, the inverted food pyramid“. ICES Journal of Marine Science 73, Nr. 6 (14.12.2015): 1697–713. http://dx.doi.org/10.1093/icesjms/fsv225.
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Abstract A global assessment of fishing patterns and fishing pressure from 110 different Ecopath models, representing marine ecosystems throughout the world and covering the period 1970–2007, show that human exploitation across trophic levels (TLs) is highly unbalanced and skewed towards low productive species at high TLs, which are around two TLs higher than the animal protein we get from terrestrial farming. Overall, exploitation levels from low trophic species were <15% of production, and only 18% of the total number of exploited groups and species were harvested >40% of their production. Generally, well-managed fisheries from temperate ecosystems were more selectively harvested at higher exploitation rates than tropical and upwelling (tropical and temperate) fisheries, resulting in potentially larger long-term changes to the ecosystem structure and functioning. The results indicate a very inefficient utilization of the food energy value of marine production. Rebuilding overfished components of the ecosystem and changing focus to balancing exploitation across a wider range of TLs, i.e. balanced harvesting, has the potential to significantly increase overall catches from global marine fisheries.
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Park, Jong-Yeon, Charles A. Stock, John P. Dunne, Xiaosong Yang und Anthony Rosati. „Seasonal to multiannual marine ecosystem prediction with a global Earth system model“. Science 365, Nr. 6450 (18.07.2019): 284–88. http://dx.doi.org/10.1126/science.aav6634.
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Climate variations have a profound impact on marine ecosystems and the communities that depend upon them. Anticipating ecosystem shifts using global Earth system models (ESMs) could enable communities to adapt to climate fluctuations and contribute to long-term ecosystem resilience. We show that newly developed ESM-based marine biogeochemical predictions can skillfully predict satellite-derived seasonal to multiannual chlorophyll fluctuations in many regions. Prediction skill arises primarily from successfully simulating the chlorophyll response to the El Niño–Southern Oscillation and capturing the winter reemergence of subsurface nutrient anomalies in the extratropics, which subsequently affect spring and summer chlorophyll concentrations. Further investigations suggest that interannual fish-catch variations in selected large marine ecosystems can be anticipated from predicted chlorophyll and sea surface temperature anomalies. This result, together with high predictability for other marine-resource–relevant biogeochemical properties (e.g., oxygen, primary production), suggests a role for ESM-based marine biogeochemical predictions in dynamic marine resource management efforts.
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Meng, Qingxiang, Likun Zhang, Hejie Wei, Enxiang Cai, Dong Xue und Mengxue Liu. „Linking Ecosystem Service Supply–Demand Risks and Regional Spatial Management in the Yihe River Basin, Central China“. Land 10, Nr. 8 (11.08.2021): 843. http://dx.doi.org/10.3390/land10080843.
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The continuous supply of ecosystem services is the foundation of the sustainable development of human society. The identification of the supply–demand relationships and risks of ecosystem services is of considerable importance to the management of regional ecosystems and the effective allocation of resources. This paper took the Yihe River Basin as the research area and selected water yield, carbon sequestration, food production, and soil conservation to assess changes in the supply and demand of ecosystem services and their matching status from 2000 to 2018. Risk identification and management zoning were also conducted. Results show the following: (1) The spatial distribution of the four ecosystems service supply and demand in the Yihe River Basin was mismatched. The food production supply levels in the middle and lower reaches and the upstream water yield, carbon sequestration, and soil conservation supply levels were high. However, most of the areas with high demand for ecosystem services were concentrated downstream. (2) From 2000 to 2018, the supply of water yield and carbon sequestration in the Yihe River Basin decreased, while that of food production and soil conservation increased. The demand for the four ecosystem services also increased. (3) Water yield faced considerable supply–demand risks. Fifty percent of the sub-basins were at a high-risk level, and the risk areas were concentrated in the middle and lower reaches. The three remaining services were mainly at low-risk levels. The Yihe River Basin was divided into eight types of supply–demand risk spatial management zones based on the ecosystem service supply and demand levels, which will help promote refined regional ecosystem management and sustainable development. The supply and demand assessment of ecosystem services from a risk perspective can integrate the information of natural ecosystems and socio-economic systems and provide scientific support for watershed spatial management.
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Ren, Jiaqi, Lizhi Xing, Yu Han und Xianlei Dong. „Nestedness-Based Measurement of Evolutionarily Stable Equilibrium of Global Production System“. Entropy 23, Nr. 8 (19.08.2021): 1077. http://dx.doi.org/10.3390/e23081077.
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A nested structure is a structural feature that is conducive to system stability formed by the coevolution of biological species in mutualistic ecosystems The coopetition relationship and value flow between industrial sectors in the global value chain are similar to the mutualistic ecosystem in nature. That is, the global economic system is always changing to form one dynamic equilibrium after another. In this paper, a nestedness-based analytical framework is used to define the generalist and specialist sectors for the purpose of analyzing the changes in the global supply pattern. We study why the global economic system can reach a stable equilibrium, what the role of different sectors play in the steady status, and how to enhance the stability of the global economic system. In detail, the domestic trade network, export trade network and import trade network of each country are extracted. Then, an econometric model is designed to analyze how the microstructure of the production system affects a country’s macroeconomic performance.
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Xia, Lei, Fei Wang, Xingmin Mu, Kai Jin, Wenyi Sun, Peng Gao und Guangju Zhao. „Water use efficiency of net primary production in global terrestrial ecosystems“. Journal of Earth System Science 124, Nr. 5 (Juli 2015): 921–31. http://dx.doi.org/10.1007/s12040-015-0587-4.
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Smith, B., D. Wårlind, A. Arneth, T. Hickler, P. Leadley, J. Siltberg und S. Zaehle. „Implications of incorporating N cycling and N limitations on primary production in an individual-based dynamic vegetation model“. Biogeosciences Discussions 10, Nr. 11 (28.11.2013): 18613–85. http://dx.doi.org/10.5194/bgd-10-18613-2013.
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Abstract. The LPJ-GUESS dynamic vegetation model uniquely combines an individual- and patch-based representation of vegetation dynamics with ecosystem biogeochemical cycling from regional to global scales. We present an updated version that includes plant and soil N dynamics, analysing the implications of accounting for C-N interactions on predictions and performance of the model. Stand structural dynamics and allometric scaling of tree growth suggested by global databases of forest stand structure and development were well-reproduced by the model in comparison to an earlier multi-model study. Accounting for N cycle dynamics improved the goodness-of-fit for broadleaved forests. N limitation associated with low N mineralisation rates reduces productivity of cold-climate and dry-climate ecosystems relative to mesic temperate and tropical ecosystems. In a model experiment emulating free-air CO2 enrichment (FACE) treatment for forests globally, N-limitation associated with low N mineralisation rates of colder soils reduces CO2-enhancement of NPP for boreal forests, while some temperate and tropical forests exhibit increased NPP enhancement. Under a business-as-usual future climate and emissions scenario, ecosystem C storage globally was projected to increase by c. 10%; additional N requirements to match this increasing ecosystem C were within the high N supply limit estimated on stoichiometric grounds in an earlier study. Our results highlight the importance of accounting for C-N interactions not only in studies of global terrestrial C cycling, but to understand underlying mechanisms on local scales and in different regional contexts.
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Wiesner, Susanne, Christina L. Staudhammer, Paul C. Stoy, Lindsay R. Boring und Gregory Starr. „Quantifying energy use efficiency via entropy production: a case study from longleaf pine ecosystems“. Biogeosciences 16, Nr. 8 (30.04.2019): 1845–63. http://dx.doi.org/10.5194/bg-16-1845-2019.
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Abstract. Ecosystems are open systems that exchange matter and energy with their environment. They differ in their efficiency in doing so as a result of their location on Earth, structure and disturbance, including anthropogenic legacy. Entropy has been proposed to be an effective metric to describe these differences as it relates energy use efficiencies of ecosystems to their thermodynamic environment (i.e., temperature) but has rarely been studied to understand how ecosystems with different disturbance legacies respond when confronted with environmental variability. We studied three sites in a longleaf pine ecosystem with varying levels of anthropogenic legacy and plant functional diversity, all of which were exposed to extreme drought. We quantified radiative (effrad), metabolic and overall entropy changes – as well as changes in exported to imported entropy (effflux) in response to drought disturbance and environmental variability using 24 total years of eddy covariance data (8 years per site). We show that structural and functional characteristics contribute to differences in energy use efficiencies at the three study sites. Our results demonstrate that ecosystem function during drought is modulated by decreased absorbed solar energy and variation in the partitioning of energy and entropy exports owing to differences in site enhanced vegetation index and/or soil water content. Low effrad and metabolic entropy as well as slow adjustment of effflux at the anthropogenically altered site prolonged its recovery from drought by approximately 1 year. In contrast, stands with greater plant functional diversity (i.e., the ones that included both C3 and C4 species) adjusted their entropy exports when faced with drought, which accelerated their recovery. Our study provides a path forward for using entropy to determine ecosystem function across different global ecosystems.
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Trueman, C. N., G. Johnston, B. O'Hea und K. M. MacKenzie. „Trophic interactions of fish communities at midwater depths enhance long-term carbon storage and benthic production on continental slopes“. Proceedings of the Royal Society B: Biological Sciences 281, Nr. 1787 (22.07.2014): 20140669. http://dx.doi.org/10.1098/rspb.2014.0669.
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Biological transfer of nutrients and materials between linked ecosystems influences global carbon budgets and ecosystem structure and function. Identifying the organisms or functional groups that are responsible for nutrient transfer, and quantifying their influence on ecosystem structure and carbon capture is an essential step for informed management of ecosystems in physically distant, but ecologically linked areas. Here, we combine natural abundance stable isotope tracers and survey data to show that mid-water and bentho-pelagic-feeding demersal fishes play an important role in the ocean carbon cycle, bypassing the detrital particle flux and transferring carbon to deep long-term storage. Global peaks in biomass and diversity of fishes at mid-slope depths are explained by competitive release of the demersal fish predators of mid-water organisms, which in turn support benthic fish production. Over 50% of the biomass of the demersal fish community at depths between 500 and 1800 m is supported by biological rather than detrital nutrient flux processes, and we estimate that bentho-pelagic fishes from the UK–Irish continental slope capture and store a volume of carbon equivalent to over 1 million tonnes of CO 2 every year.
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Smith, B., D. Wårlind, A. Arneth, T. Hickler, P. Leadley, J. Siltberg und S. Zaehle. „Implications of incorporating N cycling and N limitations on primary production in an individual-based dynamic vegetation model“. Biogeosciences 11, Nr. 7 (10.04.2014): 2027–54. http://dx.doi.org/10.5194/bg-11-2027-2014.
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Abstract. The LPJ-GUESS dynamic vegetation model uniquely combines an individual- and patch-based representation of vegetation dynamics with ecosystem biogeochemical cycling from regional to global scales. We present an updated version that includes plant and soil N dynamics, analysing the implications of accounting for C–N interactions on predictions and performance of the model. Stand structural dynamics and allometric scaling of tree growth suggested by global databases of forest stand structure and development were well reproduced by the model in comparison to an earlier multi-model study. Accounting for N cycle dynamics improved the goodness of fit for broadleaved forests. N limitation associated with low N-mineralisation rates reduces productivity of cold-climate and dry-climate ecosystems relative to mesic temperate and tropical ecosystems. In a model experiment emulating free-air CO2 enrichment (FACE) treatment for forests globally, N limitation associated with low N-mineralisation rates of colder soils reduces CO2 enhancement of net primary production (NPP) for boreal forests, while some temperate and tropical forests exhibit increased NPP enhancement. Under a business-as-usual future climate and emissions scenario, ecosystem C storage globally was projected to increase by ca. 10%; additional N requirements to match this increasing ecosystem C were within the high N supply limit estimated on stoichiometric grounds in an earlier study. Our results highlight the importance of accounting for C–N interactions in studies of global terrestrial N cycling, and as a basis for understanding mechanisms on local scales and in different regional contexts.
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Mekonnen, Mesfin M., und Winnie Gerbens-Leenes. „The Water Footprint of Global Food Production“. Water 12, Nr. 10 (26.09.2020): 2696. http://dx.doi.org/10.3390/w12102696.
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Agricultural production is the main consumer of water. Future population growth, income growth, and dietary shifts are expected to increase demand for water. The paper presents a brief review of the water footprint of crop production and the sustainability of the blue water footprint. The estimated global consumptive (green plus blue) water footprint ranges from 5938 to 8508 km3/year. The water footprint is projected to increase by as much as 22% due to climate change and land use change by 2090. Approximately 57% of the global blue water footprint is shown to violate the environmental flow requirements. This calls for action to improve the sustainability of water and protect ecosystems that depend on it. Some of the measures include increasing water productivity, setting benchmarks, setting caps on the water footprint per river basin, shifting the diets to food items with low water requirements, and reducing food waste.
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Britten, Gregory L., Michael Dowd und Boris Worm. „Changing recruitment capacity in global fish stocks“. Proceedings of the National Academy of Sciences 113, Nr. 1 (14.12.2015): 134–39. http://dx.doi.org/10.1073/pnas.1504709112.
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Marine fish and invertebrates are shifting their regional and global distributions in response to climate change, but it is unclear whether their productivity is being affected as well. Here we tested for time-varying trends in biological productivity parameters across 262 fish stocks of 127 species in 39 large marine ecosystems and high-seas areas (hereafter LMEs). This global meta-analysis revealed widespread changes in the relationship between spawning stock size and the production of juvenile offspring (recruitment), suggesting fundamental biological change in fish stock productivity at early life stages. Across regions, we estimate that average recruitment capacity has declined at a rate approximately equal to 3% of the historical maximum per decade. However, we observed large variability among stocks and regions; for example, highly negative trends in the North Atlantic contrast with more neutral patterns in the North Pacific. The extent of biological change in each LME was significantly related to observed changes in phytoplankton chlorophyll concentration and the intensity of historical overfishing in that ecosystem. We conclude that both environmental changes and chronic overfishing have already affected the productive capacity of many stocks at the recruitment stage of the life cycle. These results provide a baseline for ecosystem-based fisheries management and may help adjust expectations for future food production from the oceans.
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Zampieri, Matteo, Bruna Grizzetti, Michele Meroni, Enrico Scoccimarro, Anton Vrieling, Gustavo Naumann und Andrea Toreti. „Annual Green Water Resources and Vegetation Resilience Indicators: Definitions, Mutual Relationships, and Future Climate Projections“. Remote Sensing 11, Nr. 22 (19.11.2019): 2708. http://dx.doi.org/10.3390/rs11222708.
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Satellites offer a privileged view on terrestrial ecosystems and a unique possibility to evaluate their status, their resilience and the reliability of the services they provide. In this study, we introduce two indicators for estimating the resilience of terrestrial ecosystems from the local to the global levels. We use the Normalized Differential Vegetation Index (NDVI) time series to estimate annual vegetation primary production resilience. We use annual precipitation time series to estimate annual green water resource resilience. Resilience estimation is achieved through the annual production resilience indicator, originally developed in agricultural science, which is formally derived from the original ecological definition of resilience i.e., the largest stress that the system can absorb without losing its function. Interestingly, we find coherent relationships between annual green water resource resilience and vegetation primary production resilience over a wide range of world biomes, suggesting that green water resource resilience contributes to determining vegetation primary production resilience. Finally, we estimate the changes of green water resource resilience due to climate change using results from the sixth phase of the Coupled Model Inter-comparison Project (CMIP6) and discuss the potential consequences of global warming for ecosystem service reliability.
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Cloern, J. E., S. Q. Foster und A. E. Kleckner. „Phytoplankton primary production in the world's estuarine-coastal ecosystems“. Biogeosciences 11, Nr. 9 (07.05.2014): 2477–501. http://dx.doi.org/10.5194/bg-11-2477-2014.
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Abstract. Estuaries are biogeochemical hot spots because they receive large inputs of nutrients and organic carbon from land and oceans to support high rates of metabolism and primary production. We synthesize published rates of annual phytoplankton primary production (APPP) in marine ecosystems influenced by connectivity to land – estuaries, bays, lagoons, fjords and inland seas. Review of the scientific literature produced a compilation of 1148 values of APPP derived from monthly incubation assays to measure carbon assimilation or oxygen production. The median value of median APPP measurements in 131 ecosystems is 185 and the mean is 252 g C m−2 yr−1, but the range is large: from −105 (net pelagic production in the Scheldt Estuary) to 1890 g C m−2 yr−1 (net phytoplankton production in Tamagawa Estuary). APPP varies up to 10-fold within ecosystems and 5-fold from year to year (but we only found eight APPP series longer than a decade so our knowledge of decadal-scale variability is limited). We use studies of individual places to build a conceptual model that integrates the mechanisms generating this large variability: nutrient supply, light limitation by turbidity, grazing by consumers, and physical processes (river inflow, ocean exchange, and inputs of heat, light and wind energy). We consider method as another source of variability because the compilation includes values derived from widely differing protocols. A simulation model shows that different methods reported in the literature can yield up to 3-fold variability depending on incubation protocols and methods for integrating measured rates over time and depth. Although attempts have been made to upscale measures of estuarine-coastal APPP, the empirical record is inadequate for yielding reliable global estimates. The record is deficient in three ways. First, it is highly biased by the large number of measurements made in northern Europe (particularly the Baltic region) and North America. Of the 1148 reported values of APPP, 958 come from sites between 30 and 60° N; we found only 36 for sites south of 20° N. Second, of the 131 ecosystems where APPP has been reported, 37% are based on measurements at only one location during 1 year. The accuracy of these values is unknown but probably low, given the large interannual and spatial variability within ecosystems. Finally, global assessments are confounded by measurements that are not intercomparable because they were made with different methods. Phytoplankton primary production along the continental margins is tightly linked to variability of water quality, biogeochemical processes including ocean–atmosphere CO2 exchange, and production at higher trophic levels including species we harvest as food. The empirical record has deficiencies that preclude reliable global assessment of this key Earth system process. We face two grand challenges to resolve these deficiencies: (1) organize and fund an international effort to use a common method and measure APPP regularly across a network of coastal sites that are globally representative and sustained over time, and (2) integrate data into a unifying model to explain the wide range of variability across ecosystems and to project responses of APPP to regional manifestations of global change as it continues to unfold.
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Ferasso, Marcos, Adriana R. Wunsch Takahashi und Fernando A. Prado Gimenez. „Innovation ecosystems: a meta-synthesis“. International Journal of Innovation Science 10, Nr. 4 (03.12.2018): 495–518. http://dx.doi.org/10.1108/ijis-07-2017-0059.
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Purpose This metasynthesis aims to build a theory on the concept of innovation ecosystem from the state of the art of qualitative case studies available in indexed scientific production using interpretive synthesis (Hoon, 2013). Design/methodology/approach This research was conducted by the postulates of the metasynthesis method (Hoon, 2013) to generate theory from qualitative case studies. The authors retrieved 77 research papers from databases, of which 6 were used for synthesis purposes. Each selected research paper reported one or more cases, which were analyzed separately. At the final stage, a data synthesis was structured and the cases were crossed, which allowed the development of a schematic representation and a theoretical construction of the innovation ecosystem concept. The approach used in this research is a metatheoretical assumption from economics and management and ecology to explore the theoretical gap in the concept of innovation ecosystems. Findings There is not yet a conceptual consensus on the term, which sometimes leads researchers to address partial or complementary concepts. The analysis identified constitutive elements of an innovation ecosystem that lead to structuring a framework of organic and dynamic interrelationships that a given organization has with various external organizations, allowing the creation of innovative products in a faster way. Research limitations/implications This paper helps scholars and researchers consider a new metatheoretical perspective to analyze dynamics, constitutive elements and multilevels of an innovation ecosystem. Practical implications For practitioners, this paper sheds lights on the importance of recognizing a systemic consideration of innovation ecosystems that falls in global relationships, industry dynamics and identification of main global–local actors/enablers to produce innovations internally at a given organization. Originality/value The novelty of this paper lies in a more delineated definition and a schematic representation of an innovation ecosystem based on a global–local perspective of product creation and manufacturing and interactions that a given company has, regardless of the geographical location of its dispersed strategic partners.
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Yuan, Z. Y., und Han Y. H. Chen. „A global analysis of fine root production as affected by soil nitrogen and phosphorus“. Proceedings of the Royal Society B: Biological Sciences 279, Nr. 1743 (04.07.2012): 3796–802. http://dx.doi.org/10.1098/rspb.2012.0955.
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Fine root production is the largest component of belowground production and plays substantial roles in the biogeochemical cycles of terrestrial ecosystems. The increasing availability of nitrogen (N) and phosphorus (P) due to human activities is expected to increase aboveground net primary production (ANNP), but the response of fine root production to N and P remains unclear. If roots respond to nutrients as ANNP, fine root production is anticipated to increase with increasing soil N and P. Here, by synthesizing data along the nutrient gradient from 410 natural habitats and from 469 N and/or P addition experiments, we showed that fine root production increased in terrestrial ecosystems with an average increase along the natural N gradient of up to 0.5 per cent with increasing soil N. Fine root production also increased with soil P in natural conditions, particularly at P < 300 mg kg −1 . With N, P and combined N + P addition, fine root production increased by a global average of 27, 21 and 40 per cent, respectively. However, its responses differed among ecosystems and soil types. The global average increases in fine root production are lower than those of ANNP, indicating that above- and belowground counterparts are coupled, but production allocation shifts more to aboveground with higher soil nutrients. Our results suggest that the increasing fertilizer use and combined N deposition at present and in the future will stimulate fine root production, together with ANPP, probably providing a significant influence on atmospheric CO 2 emissions.
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Duffy, J. Emmett, Jonathan S. Lefcheck, Rick D. Stuart-Smith, Sergio A. Navarrete und Graham J. Edgar. „Biodiversity enhances reef fish biomass and resistance to climate change“. Proceedings of the National Academy of Sciences 113, Nr. 22 (16.05.2016): 6230–35. http://dx.doi.org/10.1073/pnas.1524465113.
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Fishes are the most diverse group of vertebrates, play key functional roles in aquatic ecosystems, and provide protein for a billion people, especially in the developing world. Those functions are compromised by mounting pressures on marine biodiversity and ecosystems. Because of its economic and food value, fish biomass production provides an unusually direct link from biodiversity to critical ecosystem services. We used the Reef Life Survey’s global database of 4,556 standardized fish surveys to test the importance of biodiversity to fish production relative to 25 environmental drivers. Temperature, biodiversity, and human influence together explained 47% of the global variation in reef fish biomass among sites. Fish species richness and functional diversity were among the strongest predictors of fish biomass, particularly for the large-bodied species and carnivores preferred by fishers, and these biodiversity effects were robust to potentially confounding influences of sample abundance, scale, and environmental correlations. Warmer temperatures increased biomass directly, presumably by raising metabolism, and indirectly by increasing diversity, whereas temperature variability reduced biomass. Importantly, diversity and climate interact, with biomass of diverse communities less affected by rising and variable temperatures than species-poor communities. Biodiversity thus buffers global fish biomass from climate change, and conservation of marine biodiversity can stabilize fish production in a changing ocean.
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Flach, Milan, Alexander Brenning, Fabian Gans, Markus Reichstein, Sebastian Sippel und Miguel D. Mahecha. „Vegetation modulates the impact of climate extremes on gross primary production“. Biogeosciences 18, Nr. 1 (05.01.2021): 39–53. http://dx.doi.org/10.5194/bg-18-39-2021.
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Abstract. Drought and heat events affect the uptake and sequestration of carbon in terrestrial ecosystems. Factors such as the duration, timing, and intensity of extreme events influence the magnitude of impacts on ecosystem processes such as gross primary production (GPP), i.e., the ecosystem uptake of CO2. Preceding soil moisture depletion may exacerbate these impacts. However, some vegetation types may be more resilient to climate extremes than others. This effect is insufficiently understood at the global scale and is the focus of this study. Using a global upscaled product of GPP that scales up in situ land CO2 flux observations with global satellite remote sensing, we study the impact of climate extremes at the global scale. We find that GPP in grasslands and agricultural areas is generally reduced during heat and drought events. However, we also find that forests, if considered globally, appear in general to not be particularly sensitive to droughts and heat events that occurred during the analyzed period or even show increased GPP values during these events. On the one hand, normal-to-increased GPP values are in many cases plausible, e.g., when conditions prior to the event have been particularly positive. On the other hand, however, normal-to-increased GPP values in forests may also reflect a lack of sensitivity in current remote-sensing-derived GPP products to the effects of droughts and heatwaves. The overall picture calls for a differentiated consideration of different land cover types in the assessments of risks of climate extremes for ecosystem functioning.
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Lehuger, S., B. Gabrielle, E. Larmanou, P. Laville, P. Cellier und B. Loubet. „Predicting the global warming potential of agro-ecosystems“. Biogeosciences Discussions 4, Nr. 2 (04.04.2007): 1059–92. http://dx.doi.org/10.5194/bgd-4-1059-2007.
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Abstract. Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases (GHG) contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate thus requires a capacity to predict the net exchanges of these gases in an integrated manner, as related to environmental conditions and crop management. Here, we used two year-round data sets from two intensively-monitored cropping systems in northern France to test the ability of the biophysical crop model CERES-EGC to simulate GHG exchanges at the plot-scale. The experiments involved maize and rapeseed crops on a loam and rendzina soils, respectively. The model was subsequently extrapolated to predict CO2 and N2O fluxes over an entire crop rotation. Indirect emissions (IE) arising from the production of agricultural inputs and from cropping operations were also added to the final GWP. One experimental site (involving a wheat-maize-barley rotation on a loamy soil) was a net source of GHG with a GWP of 350 kg CO2-C eq ha−1 yr−1, of which 75% were due to IE and 25% to direct N2O emissions. The other site (involving an oilseed rape-wheat-barley rotation on a rendzina) was a net sink of GHG for –250 kg CO2-C eq ha−1 yr−1, mainly due to a higher predicted C sequestration potential and C return from crops. Such modelling approach makes it possible to test various agronomic management scenarios, in order to design productive agro-ecosystems with low global warming impact.
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Yvon-Durocher, Gabriel, J. Iwan Jones, Mark Trimmer, Guy Woodward und Jose M. Montoya. „Warming alters the metabolic balance of ecosystems“. Philosophical Transactions of the Royal Society B: Biological Sciences 365, Nr. 1549 (12.07.2010): 2117–26. http://dx.doi.org/10.1098/rstb.2010.0038.
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The carbon cycle modulates climate change, via the regulation of atmospheric CO 2 , and it represents one of the most important services provided by ecosystems. However, considerable uncertainties remain concerning potential feedback between the biota and the climate. In particular, it is unclear how global warming will affect the metabolic balance between the photosynthetic fixation and respiratory release of CO 2 at the ecosystem scale. Here, we present a combination of experimental field data from freshwater mesocosms, and theoretical predictions derived from the metabolic theory of ecology to investigate whether warming will alter the capacity of ecosystems to absorb CO 2 . Our manipulative experiment simulated the temperature increases predicted for the end of the century and revealed that ecosystem respiration increased at a faster rate than primary production, reducing carbon sequestration by 13 per cent. These results confirmed our theoretical predictions based on the differential activation energies of these two processes. Using only the activation energies for whole ecosystem photosynthesis and respiration we provide a theoretical prediction that accurately quantified the precise magnitude of the reduction in carbon sequestration observed experimentally. We suggest the combination of whole-ecosystem manipulative experiments and ecological theory is one of the most promising and fruitful research areas to predict the impacts of climate change on key ecosystem services.
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Lindenmayer, David, Christian Messier, Alain Paquette und Richard J. Hobbs. „Managing tree plantations as novel socioecological systems: Australian and North American perspectives“. Canadian Journal of Forest Research 45, Nr. 10 (Oktober 2015): 1427–33. http://dx.doi.org/10.1139/cjfr-2015-0072.
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Novel ecosystems occur when new combinations of species appear within a particular biome. They typically result from direct human activity, environmental change, or the impacts of introduced species. In this paper, we argue that considering commercial tree plantations as novel ecosystems has the potential to help policy makers, resource managers, and conservation biologists better deal with the challenges and opportunities associated with managing plantations for multiple purposes at both the stand and landscape scales. We outline five inter-related issues associated with managing tree plantations, which are arguably the largest form of terrestrial novel ecosystem worldwide. This is to ensure that these areas contribute significantly to critical ecosystem services, including biodiversity conservation, in addition to their wood production role. We suggest that viewing tree plantations as novel socioecological systems may free managers from a narrow stand-based perspective and having to compare them with natural forest stands. This can help promote the development of management principles that better integrate plantations into the larger landscape so that their benefits are maximized and their potential negative ecological effects are minimized.
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Zanotelli, D., L. Montagnani, G. Manca und M. Tagliavini. „Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy-covariance, biometric and continuous soil chamber measurements“. Biogeosciences Discussions 9, Nr. 10 (15.10.2012): 14091–143. http://dx.doi.org/10.5194/bgd-9-14091-2012.
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Abstract. Carbon use efficiency (CUE) is a functional parameter that could possibly link the current increasingly accurate global estimates of gross primary production with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, net primary production (NPP) and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a~measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross-check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard both net ecosystem production and gross primary production on yearly basis, 380 ± 30 g C m−2 and 1263 ± 189 g C m−2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruits: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.09, was higher than the previously suggested constant values of 0.47–0.50. Low nitrogen investment in fruits, the limited root-apparatus, and the optimal growth temperature and nutritional condition observed at the site are suggested to be explanatory variables for the high CUE observed.
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Cloern, J. E., S. Q. Foster und A. E. Kleckner. „Review: phytoplankton primary production in the world's estuarine-coastal ecosystems“. Biogeosciences Discussions 10, Nr. 11 (15.11.2013): 17725–83. http://dx.doi.org/10.5194/bgd-10-17725-2013.
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Abstract. Estuaries are biogeochemical hot spots because they receive large inputs of nutrients and organic carbon from land and oceans to support high rates of metabolism and primary production. We synthesize published rates of annual phytoplankton primary production (APPP) in marine ecosystems influenced by connectivity to land – estuaries, bays, lagoons, fjords and inland seas. Review of the scientific literature produced a compilation of 1148 values of APPP derived from monthly incubation assays to measure carbon assimilation or oxygen production. The median value of median APPP measurements in 131 ecosystems is 185 and the mean is 252 g C m−2 yr−1, but the range is large: from −105 (net pelagic production in the Scheldt Estuary) to 1890 g C m−2 yr−1 (net phytoplankton production in Tamagawa Estuary). APPP varies up to 10-fold within ecosystems and 5-fold from year-to-year (but we only found 8 APPP series longer than a decade so our knowledge of decadal-scale variability is limited). We use studies of individual places to build a conceptual model that integrates the mechanisms generating this large variability: nutrient supply, light limitation by turbidity, grazing by consumers, and physical processes (river inflow, ocean exchange, and inputs of heat, light and wind energy). We consider method as another source of variability because the compilation includes values derived from widely differing protocols. A simulation model shows that different methods can yield up to 3-fold variability depending on incubation protocols and methods for integrating measured rates over time and depth. Although attempts have been made to upscale measures of estuarine-coastal APPP, the empirical record is inadequate for yielding reliable global estimates. The record is deficient in three ways. First, it is highly biased by the large number of measurements made in northern Europe (particularly the Baltic region) and North America. Of the 1148 reported values of APPP, 958 come from sites between 30° N and 60° N; we found only 36 for sites south of 20° N. Second, of the 131 ecosystems where APPP has been reported, 37% are based on measurements at only one location during one year. The accuracy of these values is unknown but probably low, given the large inter-annual and spatial variability within ecosystems. Finally, global assessments are confounded by measurements that are not intercomparable because they were made with a broad range of methods. Phytoplankton primary production along the continental margins is tightly linked to variability of water quality, biogeochemical processes including ocean-atmosphere CO2 exchange, and production at higher trophic levels including species we harvest as food. The empirical record has deficiencies that preclude reliable global assessment of this key Earth-system process. We face two grand challenges to resolve these deficiencies: (1) organize and fund an international effort to use a common method and measure APPP regularly across a network of coastal sites that are globally representative and sustained over time, and (2) integrate data into a unifying model to explain the wide range of variability across ecosystems and to project responses of APPP to regional manifestations of global change as it continues to unfold.
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Prowe, A. E. F., M. Pahlow, S. Dutkiewicz und A. Oschlies. „Small diversity effects on ocean primary production under environmental change in a diversity-resolving ocean ecosystem model“. Biogeosciences Discussions 10, Nr. 7 (31.07.2013): 12571–91. http://dx.doi.org/10.5194/bgd-10-12571-2013.
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Abstract. Marine ecosystem models used to investigate how global change affects ocean ecosystems and their functioning typically omit pelagic diversity. Diversity, however, can affect functions such as primary production and their sensitivity to environmental changes. Using a global ocean ecosystem model that explicitly resolves phytoplankton diversity within four phytoplankton functional types (PFTs) we investigate the model's ability to capture diversity effects on primary production under environmental change. An idealized scenario with a sudden reduction in vertical mixing causes diversity and primary-production changes that turn out to be largely independent of the number of coexisting phytoplankton types. The model provides a small number of niches with respect to nutrient use in accordance with the PFTs defined in the model, and increasing the number of phytoplankton types increases the resolution within the niches. The variety of traits and trade-offs resolved in the model constrains diversity effects such as niche complementarity, which operate between, but not within PFTs. The number and nature of the niches formulated in the model, for example via trade-offs or different PFTs, thus determines the diversity effects on ecosystem functioning captured in ocean ecosystem models.
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YE, You-Ting, und Da-Lin SHI. „Effects of global change on key processes of primary production in marine ecosystems“. Chinese Journal of Plant Ecology 44, Nr. 5 (2020): 575–82. http://dx.doi.org/10.17521/cjpe.2019.0313.
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Calbet, Albert. „Mesozooplankton grazing effect on primary production: A global comparative analysis in marine ecosystems“. Limnology and Oceanography 46, Nr. 7 (November 2001): 1824–30. http://dx.doi.org/10.4319/lo.2001.46.7.1824.
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Zhao, Wei, Wenfeng Tan und Shiqing Li. „High leaf area index inhibits net primary production in global temperate forest ecosystems“. Environmental Science and Pollution Research 28, Nr. 18 (09.01.2021): 22602–11. http://dx.doi.org/10.1007/s11356-020-11928-0.
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Montgomery, Ian, Tancredi Caruso und Neil Reid. „Hedgerows as Ecosystems: Service Delivery, Management, and Restoration“. Annual Review of Ecology, Evolution, and Systematics 51, Nr. 1 (02.11.2020): 81–102. http://dx.doi.org/10.1146/annurev-ecolsys-012120-100346.
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Hedge density, structure, and function vary with primary production and slope gradient and are subject to other diverse factors. Hedgerows are emerging ecosystems with both above- and belowground components. Functions of hedges can be categorized as provisioning, regulating, cultural, and supporting ecosystem services; these functions include food production, noncrop food and wood production, firewood production, pollination, pest control, soil conservation and quality improvement, mitigation of water flux and availability, carbon sequestration, landscape connectivity and character maintenance, and contributions to biodiversity. Urban hedges provide a relatively equitable microclimate and critical connections between green spaces and enhance human health and well-being through contact with biodiversity. Soil and water conservation are well researched in tropical hedges but less is known about their contribution to pollination, pest control, and biodiversity. Establishing a minimum hedge width and longer intervals between cutting of temperate hedges would enhance biosecurity and promote carbon sequestration and biodiversity. Hedges have a global role in mitigating biodiversity loss and climate change, which restoration should maximize, notwithstanding regional character.
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Szuwalski, Cody S., Matthew G. Burgess, Christopher Costello und Steven D. Gaines. „High fishery catches through trophic cascades in China“. Proceedings of the National Academy of Sciences 114, Nr. 4 (27.12.2016): 717–21. http://dx.doi.org/10.1073/pnas.1612722114.
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Indiscriminate and intense fishing has occurred in many marine ecosystems around the world. Although this practice may have negative effects on biodiversity and populations of individual species, it may also increase total fishery productivity by removing predatory fish. We examine the potential for this phenomenon to explain the high reported wild catches in the East China Sea—one of the most productive ecosystems in the world that has also had its catch reporting accuracy and fishery management questioned. We show that reported catches can be approximated using an ecosystem model that allows for trophic cascades (i.e., the depletion of predators and consequent increases in production of their prey). This would be the world’s largest known example of marine ecosystem “engineering” and suggests that trade-offs between conservation and food production exist. We project that fishing practices could be modified to increase total catches, revenue, and biomass in the East China Sea, but single-species management would decrease both catches and revenue by reversing the trophic cascades. Our results suggest that implementing single-species management in currently lightly managed and highly exploited multispecies fisheries (which account for a large fraction of global fish catch) may result in decreases in global catch. Efforts to reform management in these fisheries will need to consider system wide impacts of changes in management, rather than focusing only on individual species.
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Schnedler-Meyer, Nicolas Azaña, Patrizio Mariani und Thomas Kiørboe. „The global susceptibility of coastal forage fish to competition by large jellyfish“. Proceedings of the Royal Society B: Biological Sciences 283, Nr. 1842 (16.11.2016): 20161931. http://dx.doi.org/10.1098/rspb.2016.1931.
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Competition between large jellyfish and forage fish for zooplankton prey is both a possible cause of jellyfish increases and a concern for the management of marine ecosystems and fisheries. Identifying principal factors affecting this competition is therefore important for marine management, but the lack of both good quality data and a robust theoretical framework have prevented general global analyses. Here, we present a general mechanistic food web model that considers fundamental differences in feeding modes and predation pressure between fish and jellyfish. The model predicts forage fish dominance at low primary production, and a shift towards jellyfish with increasing productivity, turbidity and fishing. We present an index of global ecosystem susceptibility to shifts in fish–jellyfish dominance that compares well with data on jellyfish distributions and trends. The results are a step towards better understanding the processes that govern jellyfish occurrences globally and highlight the advantage of considering feeding traits in ecosystem models.
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Nagelkerken, Ivan, und Sean D. Connell. „Global alteration of ocean ecosystem functioning due to increasing human CO2 emissions“. Proceedings of the National Academy of Sciences 112, Nr. 43 (12.10.2015): 13272–77. http://dx.doi.org/10.1073/pnas.1510856112.
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Rising anthropogenic CO2 emissions are anticipated to drive change to ocean ecosystems, but a conceptualization of biological change derived from quantitative analyses is lacking. Derived from multiple ecosystems and latitudes, our metaanalysis of 632 published experiments quantified the direction and magnitude of ecological change resulting from ocean acidification and warming to conceptualize broadly based change. Primary production by temperate noncalcifying plankton increases with elevated temperature and CO2, whereas tropical plankton decreases productivity because of acidification. Temperature increases consumption by and metabolic rates of herbivores, but this response does not translate into greater secondary production, which instead decreases with acidification in calcifying and noncalcifying species. This effect creates a mismatch with carnivores whose metabolic and foraging costs increase with temperature. Species diversity and abundances of tropical as well as temperate species decline with acidification, with shifts favoring novel community compositions dominated by noncalcifiers and microorganisms. Both warming and acidification instigate reduced calcification in tropical and temperate reef-building species. Acidification leads to a decline in dimethylsulfide production by ocean plankton, which as a climate gas, contributes to cloud formation and maintenance of the Earth’s heat budget. Analysis of responses in short- and long-term experiments and of studies at natural CO2 vents reveals little evidence of acclimation to acidification or temperature changes, except for microbes. This conceptualization of change across whole communities and their trophic linkages forecast a reduction in diversity and abundances of various key species that underpin current functioning of marine ecosystems.
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Hobbs, William O., Rolf D. Vinebrooke und Alexander P. Wolfe. „Biogeochemical responses of two alpine lakes to climate change and atmospheric deposition, Jasper and Banff National parks, Canadian Rocky Mountains“. Canadian Journal of Fisheries and Aquatic Sciences 68, Nr. 8 (August 2011): 1480–94. http://dx.doi.org/10.1139/f2011-058.
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The sensitivity of remote alpine ecosystems to global change has been documented by 20th century changes in climate, glacial recession, and terrestrial and aquatic ecosystems. Here we present sedimentary records of biogeochemical responses in two alpine lake ecosystems to multiple environmental drivers over the last ∼500 years in Banff and Jasper National Parks (Alberta, Canada). We combine paleoecological measures of primary production and diatom community structure with geochemical proxies of reactive N (Nr) deposition to describe the nature and rate of recent ecosystem changes. Curator Lake in Jasper shows a strong diatom response to the limnological effects of climate warming (e.g., thermal stratification), but little evidence of changes in Nr cycling over the last ∼500 years. The response of McConnell Lake in Banff to climate change is strongly mediated by glacial activity within the catchment and changing inputs of Nr. Our findings highlight the range of limnological responses that may be expressed by similar ecosystems subjected to comparable abiotic stressors, while further documenting the magnitude of the ecological footprint associated with recent environmental change in mountain park environments.
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Zanotelli, D., L. Montagnani, G. Manca und M. Tagliavini. „Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy covariance, biometric and continuous soil chamber measurements“. Biogeosciences 10, Nr. 5 (07.05.2013): 3089–108. http://dx.doi.org/10.5194/bg-10-3089-2013.
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Abstract. Carbon use efficiency (CUE), the ratio of net primary production (NPP) over gross primary production (GPP), is a functional parameter that could possibly link the current increasingly accurate global GPP estimates with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, NPP and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard, both net ecosystem production and gross primary production on a yearly basis, 380 ± 30 g C m−2 and 1263 ± 189 g C m−2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruit: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.12, was higher than the previously suggested constant values of 0.47–0.50. Low nitrogen investment in fruit, the limited root apparatus, and the optimal growth temperature and nutritional condition observed at the site are suggested to be explanatory variables for the high CUE observed.
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Wang, Haibo, Xin Li, Mingguo Ma und Liying Geng. „Improving Estimation of Gross Primary Production in Dryland Ecosystems by a Model-Data Fusion Approach“. Remote Sensing 11, Nr. 3 (22.01.2019): 225. http://dx.doi.org/10.3390/rs11030225.
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Accurate and continuous monitoring of the production of arid ecosystems is of great importance for global and regional carbon cycle estimation. However, the magnitude of carbon sequestration in arid regions and its contribution to the global carbon cycle is poorly understood due to the worldwide paucity of measurements of carbon exchange in arid ecosystems. The Moderate Resolution Imaging Spectroradiometer (MODIS) gross primary productivity (GPP) product provides worldwide high-frequency monitoring of terrestrial GPP. While there have been a large number of studies to validate the MODIS GPP product with ground-based measurements over a range of biome types. Few studies have comprehensively validated the performance of MODIS estimates in arid and semi-arid ecosystems, especially for the newly released Collection 6 GPP products, whose resolution have been improved from 1000 m to 500 m. Thus, this study examined the performance of MODIS-derived GPP by compared with eddy covariance (EC)-observed GPP at different timescales for the main ecosystems in arid and semi-arid regions of China. Meanwhile, we also improved the estimation of MODIS GPP by using in situ meteorological forcing data and optimization of biome-specific parameters with the Bayesian approach. Our results revealed that the current MOD17A2H GPP algorithm could, on the whole, capture the broad trends of GPP at eight-day time scales for the most investigated sites. However, GPP was underestimated in some ecosystems in the arid region, especially for the irrigated cropland and forest ecosystems (with R2 = 0.80, RMSE = 2.66 gC/m2/day and R2 = 0.53, RMSE = 2.12 gC/m2/day, respectively). At the eight-day time scale, the slope of the original MOD17A2H GPP relative to the EC-based GPP was only 0.49, which showed significant underestimation compared with tower-based GPP. However, after using in situ meteorological data to optimize the biome-based parameters of MODIS GPP algorithm, the model could explain 91% of the EC-observed GPP of the sites. Our study revealed that the current MODIS GPP model works well after improving the maximum light-use efficiency (εmax or LUEmax), as well as the temperature and water-constrained parameters of the main ecosystems in the arid region. Nevertheless, there are still large uncertainties surrounding GPP modelling in dryland ecosystems, especially for desert ecosystems. Further improvements in GPP simulation in dryland ecosystems are needed in future studies, for example, improvements of remote sensing products and the GPP estimation algorithm, implementation of data-driven methods, or physiology models.
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Schneider, David, und David Cameron Duffy. „Historical variation in guano production from the Peruvian and Benguela upwelling ecosystems“. Climatic Change 13, Nr. 3 (Dezember 1988): 309–16. http://dx.doi.org/10.1007/bf00139812.
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Prowe, A. E. F., M. Pahlow, S. Dutkiewicz und A. Oschlies. „How important is diversity for capturing environmental-change responses in ecosystem models?“ Biogeosciences 11, Nr. 12 (27.06.2014): 3397–407. http://dx.doi.org/10.5194/bg-11-3397-2014.
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Abstract. Marine ecosystem models used to investigate how global change affects ocean ecosystems and their functioning typically omit pelagic plankton diversity. Diversity, however, may affect functions such as primary production and their sensitivity to environmental changes. Here we use a global ocean ecosystem model that explicitly resolves phytoplankton diversity by defining subtypes within four phytoplankton functional types (PFTs). We investigate the model's ability to capture diversity effects on primary production under environmental change. An idealized scenario with a sudden reduction in vertical mixing causes diversity and primary-production changes that turn out to be largely independent of the number of coexisting phytoplankton subtypes. The way diversity is represented in the model provides a small number of niches with respect to nutrient use in accordance with the PFTs defined in the model. Increasing the number of phytoplankton subtypes increases the resolution within the niches. Diversity effects such as niche complementarity operate between, but not within PFTs, and are constrained by the variety of traits and trade-offs resolved in the model. The number and nature of the niches formulated in the model, for example via trade-offs or different PFTs, thus determines the diversity effects on ecosystem functioning captured in ocean ecosystem models.