Land use intensification alters ecosystem multifunctionality via loss of biodiversity and changes to functional composition

OpenAIRE

Allan, Eric; Manning, Pete; et al

2015-01-01

Global change, especially land-use intensification, affects human well-being by impacting the deliv-ery of multiple ecosystem services (multifunctionality). However, whether biodiversity loss is amajor component of global change effects on multifunctionality in real-world ecosystems, as inexperimental ones, remains unclear. Therefore, we assessed biodiversity, functional compositionand 14 ecosystem services on 150 agricultural grasslands differing in land-use intensity. We alsointroduce five mu...

Land use intensification alters ecosystem multifunctionality via loss of biodiversity and changes to functional composition.

OpenAIRE

Allan Eric; Manning Pete; Alt Fabian; Binkenstein Julia; Blaser Stefan; Blüthgen Nico; Böhm Stefan; Grassein Fabrice; Hölzel Norbert; Klaus Valentin H.; Kleinebecker Till; Morrys Elisabeth Kathryn; Oelmann Yvonne; Prati Daniel; Renner Sven C.

2015-01-01

Abstract Global change, especially land?use intensification, affects human well?being by impacting the delivery of multiple ecosystem services (multifunctionality). However, whether biodiversity loss is a major component of global change effects on multifunctionality in real?world ecosystems, as in experimental ones, remains unclear. Therefore, we assessed biodiversity, functional composition and 14 ecosystem services on 150 agricultural grasslands differing in land?use intensity. We also int...

Dominance, biomass and extinction resistance determine the consequences of biodiversity loss for multiple coastal ecosystem processes.

Science.gov (United States)

Davies, Thomas W; Jenkins, Stuart R; Kingham, Rachel; Kenworthy, Joseph; Hawkins, Stephen J; Hiddink, Jan G

2011-01-01

Key ecosystem processes such as carbon and nutrient cycling could be deteriorating as a result of biodiversity loss. However, currently we lack the ability to predict the consequences of realistic species loss on ecosystem processes. The aim of this study was to test whether species contributions to community biomass can be used as surrogate measures of their contribution to ecosystem processes. These were gross community productivity in a salt marsh plant assemblage and an intertidal macroalgae assemblage; community clearance of microalgae in sessile suspension feeding invertebrate assemblage; and nutrient uptake in an intertidal macroalgae assemblage. We conducted a series of biodiversity manipulations that represented realistic species extinction sequences in each of the three contrasting assemblages. Species were removed in a subtractive fashion so that biomass was allowed to vary with each species removal, and key ecosystem processes were measured at each stage of community disassembly. The functional contribution of species was directly proportional to their contribution to community biomass in a 1:1 ratio, a relationship that was consistent across three contrasting marine ecosystems and three ecosystem processes. This suggests that the biomass contributed by a species to an assemblage can be used to approximately predict the proportional decline in an ecosystem process when that species is lost. Such predictions represent "worst case scenarios" because, over time, extinction resilient species can offset the loss of biomass associated with the extinction of competitors. We also modelled a "best case scenario" that accounts for compensatory responses by the extant species with the highest per capita contribution to ecosystem processes. These worst and best case scenarios could be used to predict the minimum and maximum species required to sustain threshold values of ecosystem processes in the future.

Dominance, biomass and extinction resistance determine the consequences of biodiversity loss for multiple coastal ecosystem processes.

Directory of Open Access Journals (Sweden)

Thomas W Davies

Full Text Available Key ecosystem processes such as carbon and nutrient cycling could be deteriorating as a result of biodiversity loss. However, currently we lack the ability to predict the consequences of realistic species loss on ecosystem processes. The aim of this study was to test whether species contributions to community biomass can be used as surrogate measures of their contribution to ecosystem processes. These were gross community productivity in a salt marsh plant assemblage and an intertidal macroalgae assemblage; community clearance of microalgae in sessile suspension feeding invertebrate assemblage; and nutrient uptake in an intertidal macroalgae assemblage. We conducted a series of biodiversity manipulations that represented realistic species extinction sequences in each of the three contrasting assemblages. Species were removed in a subtractive fashion so that biomass was allowed to vary with each species removal, and key ecosystem processes were measured at each stage of community disassembly. The functional contribution of species was directly proportional to their contribution to community biomass in a 1:1 ratio, a relationship that was consistent across three contrasting marine ecosystems and three ecosystem processes. This suggests that the biomass contributed by a species to an assemblage can be used to approximately predict the proportional decline in an ecosystem process when that species is lost. Such predictions represent "worst case scenarios" because, over time, extinction resilient species can offset the loss of biomass associated with the extinction of competitors. We also modelled a "best case scenario" that accounts for compensatory responses by the extant species with the highest per capita contribution to ecosystem processes. These worst and best case scenarios could be used to predict the minimum and maximum species required to sustain threshold values of ecosystem processes in the future.

Diversity loss with persistent human disturbance increases vulnerability to ecosystem collapse.

Science.gov (United States)

MacDougall, A S; McCann, K S; Gellner, G; Turkington, R

2013-02-07

Long-term and persistent human disturbances have simultaneously altered the stability and diversity of ecological systems, with disturbances directly reducing functional attributes such as invasion resistance, while eliminating the buffering effects of high species diversity. Theory predicts that this combination of environmental change and diversity loss increases the risk of abrupt and potentially irreversible ecosystem collapse, but long-term empirical evidence from natural systems is lacking. Here we demonstrate this relationship in a degraded but species-rich pyrogenic grassland in which the combined effects of fire suppression, invasion and trophic collapse have created a species-poor grassland that is highly productive, resilient to yearly climatic fluctuations, and resistant to invasion, but vulnerable to rapid collapse after the re-introduction of fire. We initially show how human disturbance has created a negative relationship between diversity and function, contrary to theoretical predictions. Fire prevention since the mid-nineteenth century is associated with the loss of plant species but it has stabilized high-yield annual production and invasion resistance, comparable to a managed high-yield low-diversity agricultural system. In managing for fire suppression, however, a hidden vulnerability to sudden environmental change emerges that is explained by the elimination of the buffering effects of high species diversity. With the re-introduction of fire, grasslands only persist in areas with remnant concentrations of native species, in which a range of rare and mostly functionally redundant plants proliferate after burning and prevent extensive invasion including a rapid conversion towards woodland. This research shows how biodiversity can be crucial for ecosystem stability despite appearing functionally insignificant beforehand, a relationship probably applicable to many ecosystems given the globally prevalent combination of intensive long-term land

The organic nature and atmosphere-climate dependency of nitrogen loss from forest watershed ecosystems

OpenAIRE

Brookshire, E. N. J.

2006-01-01

In this dissertation I describe how coupled internal cycling and external forcing from the atmosphere and climate can regulate the dynamics of nitrogen (N) loss from forest watersheds. I address three major gaps in our understanding of the global N cycle: 1) the role of dissolved organic N (DON) in internal N cycling in low-N ecosystems; 2) The influence of atmospheric pollution on DON production and loss from forests; and 3) the inherent climate sensitivity of forest N cycling and loss. In...

Finding all sorting tandem duplication random loss operations

DEFF Research Database (Denmark)

Bernt, Matthias; Chen, Kuan Yu; Chen, Ming Chiang

2011-01-01

A tandem duplication random loss (TDRL) operation duplicates a contiguous segment of genes, followed by the random loss of one copy of each of the duplicated genes. Although the importance of this operation is founded by several recent biological studies, it has been investigated only rarely from...

AI techniques for optimizing multi-objective reservoir operation upon human and riverine ecosystem demands

Science.gov (United States)

Tsai, Wen-Ping; Chang, Fi-John; Chang, Li-Chiu; Herricks, Edwin E.

2015-11-01

Flow regime is the key driver of the riverine ecology. This study proposes a novel hybrid methodology based on artificial intelligence (AI) techniques for quantifying riverine ecosystems requirements and delivering suitable flow regimes that sustain river and floodplain ecology through optimizing reservoir operation. This approach addresses issues to better fit riverine ecosystem requirements with existing human demands. We first explored and characterized the relationship between flow regimes and fish communities through a hybrid artificial neural network (ANN). Then the non-dominated sorting genetic algorithm II (NSGA-II) was established for river flow management over the Shihmen Reservoir in northern Taiwan. The ecosystem requirement took the form of maximizing fish diversity, which could be estimated by the hybrid ANN. The human requirement was to provide a higher satisfaction degree of water supply. The results demonstrated that the proposed methodology could offer a number of diversified alternative strategies for reservoir operation and improve reservoir operational strategies producing downstream flows that could meet both human and ecosystem needs. Applications that make this methodology attractive to water resources managers benefit from the wide spread of Pareto-front (optimal) solutions allowing decision makers to easily determine the best compromise through the trade-off between reservoir operational strategies for human and ecosystem needs.

Group points to underlying causes of ecosystem, blodiversity loss

Science.gov (United States)

Showstack, Randy

Freshwater diversion, urban water pollution,and overfishing are leading to the decline of some of Pakistan's coastal mangrove ecosystems. In Mexico's Calakmul Biosphere Reserve, near the border of Guatemala, population growth and poverty are pushing forest clearing. Meanwhile, in Chilika Lake in southeast India, changes in economic policies and global markets have led to changes in commercial aquaculture that is partly responsible for the decline of local fisheries and the bird population.These are the conclusions of some of the 10 case studies contained in a World Wildlife Fund (WWF) report, issued on July 6, that examines forests, wetlands, steppes, mangroves, and other habitats to determine the underlying causes for biodiversity loss.

24 CFR 207.252a - Premiums-operating loss loans.

Science.gov (United States)

2010-04-01

... Premiums—operating loss loans. (a) The mortgagee, upon the insurance endorsement of the increase loan credit instrument covering the operating loss loan, shall pay to the Commissioner a first mortgage...

The biodiversity-dependent ecosystem service debt.

Science.gov (United States)

Isbell, Forest; Tilman, David; Polasky, Stephen; Loreau, Michel

2015-02-01

Habitat destruction is driving biodiversity loss in remaining ecosystems, and ecosystem functioning and services often directly depend on biodiversity. Thus, biodiversity loss is likely creating an ecosystem service debt: a gradual loss of biodiversity-dependent benefits that people obtain from remaining fragments of natural ecosystems. Here, we develop an approach for quantifying ecosystem service debts, and illustrate its use to estimate how one anthropogenic driver, habitat destruction, could indirectly diminish one ecosystem service, carbon storage, by creating an extinction debt. We estimate that c. 2-21 Pg C could be gradually emitted globally in remaining ecosystem fragments because of plant species loss caused by nearby habitat destruction. The wide range for this estimate reflects substantial uncertainties in how many plant species will be lost, how much species loss will impact ecosystem functioning and whether plant species loss will decrease soil carbon. Our exploratory analysis suggests that biodiversity-dependent ecosystem service debts can be globally substantial, even when locally small, if they occur diffusely across vast areas of remaining ecosystems. There is substantial value in conserving not only the quantity (area), but also the quality (biodiversity) of natural ecosystems for the sustainable provision of ecosystem services. © 2014 John Wiley & Sons Ltd/CNRS.

26 CFR 1.172-9 - Election with respect to portion of net operating loss attributable to foreign expropriation loss.

Science.gov (United States)

2010-04-01

... operating loss attributable to foreign expropriation loss. 1.172-9 Section 1.172-9 Internal Revenue INTERNAL... operating loss attributable to foreign expropriation loss. (a) In general. If a taxpayer has a net operating loss for a taxable year ending after December 31, 1958, and if the foreign expropriation loss for such...

24 CFR 236.253 - Premiums-operating loss loans.

Science.gov (United States)

2010-04-01

... Obligations for Mortgage Insurance § 236.253 Premiums—operating loss loans. All of the provisions of § 207.252a of this chapter relating to mortgage insurance premiums on operating loss loans shall apply to... Act the mortgage insurance premiums due in accordance with § 207.252a shall be calculated on the basis...

Allowing variance may enlarge the safe operating space for exploited ecosystems.

Science.gov (United States)

Carpenter, Stephen R; Brock, William A; Folke, Carl; van Nes, Egbert H; Scheffer, Marten

2015-11-17

Variable flows of food, water, or other ecosystem services complicate planning. Management strategies that decrease variability and increase predictability may therefore be preferred. However, actions to decrease variance over short timescales (2-4 y), when applied continuously, may lead to long-term ecosystem changes with adverse consequences. We investigated the effects of managing short-term variance in three well-understood models of ecosystem services: lake eutrophication, harvest of a wild population, and yield of domestic herbivores on a rangeland. In all cases, actions to decrease variance can increase the risk of crossing critical ecosystem thresholds, resulting in less desirable ecosystem states. Managing to decrease short-term variance creates ecosystem fragility by changing the boundaries of safe operating spaces, suppressing information needed for adaptive management, cancelling signals of declining resilience, and removing pressures that may build tolerance of stress. Thus, the management of variance interacts strongly and inseparably with the management of resilience. By allowing for variation, learning, and flexibility while observing change, managers can detect opportunities and problems as they develop while sustaining the capacity to deal with them.

A universal method to assess the potential of phosphorus loss from soil to aquatic ecosystems.

Science.gov (United States)

Pöthig, Rosemarie; Behrendt, Horst; Opitz, Dieter; Furrer, Gerhard

2010-02-01

Phosphorus loss from terrestrial to the aquatic ecosystems contributes to eutrophication of surface waters. To maintain the world's vital freshwater ecosystems, the reduction of eutrophication is crucial. This needs the prevention of overfertilization of agricultural soils with phosphorus. However, the methods of risk assessment for the P loss potential from soils lack uniformity and are difficult for routine analysis. Therefore, the efficient detection of areas with a high risk of P loss requires a simple and universal soil test method that is cost effective and applicable in both industrialized and developing countries. Soils from areas which varied highly in land use and soil type were investigated regarding the degree of P saturation (DPS) as well as the equilibrium P concentration (EPC(0)) and water-soluble P (WSP) as indicators for the potential of P loss. The parameters DPS and EPC(0) were determined from P sorption isotherms. Our investigation of more than 400 soil samples revealed coherent relationships between DPS and EPC(0) as well as WSP. The complex parameter DPS, characterizing the actual P status of soil, is accessible from a simple standard measurement of WSP based on the equation [Formula: see text]. The parameter WSP in this equation is a function of remaining phosphorous sorption capacity/total accumulated phosphorous (SP/TP). This quotient is independent of soil type due to the mutual compensation of the factors SP and TP. Thus, the relationship between DPS and WSP is also independent of soil type. The degree of P saturation, which reflects the actual state of P fertilization of soil, can be calculated from the easily accessible parameter WSP. Due to the independence from soil type and land use, the relation is valid for all soils. Values of WSP, which exceed 5 mg P/kg soil, signalize a P saturation between 70% and 80% and thus a high risk of P loss from soil. These results reveal a new approach of risk assessment for P loss from soils to

Mowing exacerbates the loss of ecosystem stability under nitrogen enrichment in a temperate grassland.

Science.gov (United States)

Zhang, Yunhai; Loreau, Michel; He, Nianpeng; Zhang, Guangming; Han, Xingguo

2017-08-04

1. Global reactive nitrogen (N) is projected to further increase in the coming years. Previous studies have demonstrated that N enrichment weakens the temporal stability of the ecosystem and the primary productivity through decreased biodiversity and species asynchrony. Mowing is a globally common practise in grasslands; and infrequent mowing can maintain or increase plant diversity under N enrichment conditions. However, it is unclear how infrequent mowing affects ecosystem stability in the face of N enrichment. 2. By independently manipulating the frequency (twice vs. monthly additions per year) and rate (i.e. 0, 1, 2, 3, 5, 10, 15, 20, and 50 g N m -2 year -1 ) of NH 4 NO 3 inputs and mowing (unmown vs. mown) over 3 years (2011-2013) in a temperate grassland of northern China, we aimed to examine the interactive effects of N enrichment and mowing on ecosystem stability. 3. The results show that mowing maintained a positive relationship between species richness and ecosystem stability despite N addition, but that it exacerbated the negative effects of N addition on ecosystem stability. Mowing increased mean primary productivity and plant species richness, but it also increased the synchrony of population fluctuations and the variability of primary productivity under N enrichment, thereby contributing to a decline in the ecosystem stability. 4. Thus, our study reveals that infrequent mowing can buffer the negative effects of N enrichment on biodiversity to some extent and further increase the primary productivity, but it exacerbates the loss of ecosystem stability with N enrichment, thereby threatening local and/or semiarid regional food security.

The Need for F/LOSS (Governance Operations

Directory of Open Access Journals (Sweden)

Andrew Back

2008-07-01

Full Text Available The case for the effective operation of Free/Libre and Open Source Software (F/LOSS in the enterprise has never been stronger. Yet in some quarters, the chasm between senior management's perception of the penetration of F/LOSS within their organization, and the reality, has never been wider. And when you consider that Gartner predicts that "by 2012 more than 90% of enterprises will use open source in direct or embedded form", this suggests that the development of an effective F/LOSS policy will become increasingly necessary for business operations. Many enterprises, for now, are sourcing the majority of their F/LOSS solutions via a vendor. This does not remove the need for governance. Even with commercial arrangements in place, it is crucial that business have an understanding of F/LOSS communities: what drives them, how to interact with them, and what obligations they may have to them. The game has changed and innovation is no longer the reserve of software vendors with large development budgets. Software development is now enabled by open licenses that afford great freedoms and, in doing so, facilitate widespread collaboration. With this unprecedented pace of innovation, comes new obligations. We argue that the need for education around F/LOSS communities and licensing is clear.

Activation of the operational ecohydrodynamic model (3D CEMBS - the ecosystem module

Directory of Open Access Journals (Sweden)

Jaromir Jakacki

2013-08-01

Full Text Available The paper describes the ecohydrodynamic predictive model - the ecosystem module - for assessing the state of the Baltic marine environment and the Baltic ecosystem. The Baltic Sea model 3D CEMBS (the Coupled Ecosystem Model of the Baltic Sea is based on the Community Earth System Model, which was adopted for the Baltic Sea as a coupled sea-ice-ecosystem model. The 3D CEMBS model uses: (i hydrodynamic equations describing water movement, (ii thermodynamic equations, (iii equations describing the concentration distribution of chemical variables in the sea, and (iv equations describing the exchange of matter between individual groups of organisms and their environment that make allowance for the kinetics of biochemical processes. The ecosystem model consists of 11 main components: three classes of phytoplankton (small phytoplankton, large phytoplankton represented mainly by diatoms and summer species, mostly cyanobacteria expressed in units of carbon and chlorophyll a as separate variables, zooplankton, pelagic detritus, dissolved oxygen and nutrients (nitrate, ammonium, phosphate and silicate. In operational mode, 48-hour atmospheric forecasts provided by the UM model from the Interdisciplinary Centre for Mathematical and Computational Modelling of Warsaw University (ICM are used. All model forecasts are available on the website http://deep.iopan.gda.pl/CEMBaltic/new_lay/index.php. The results presented in this paper show that the 3D CEMBS model is operating correctly.

Invasive species triggers a massive loss of ecosystem services through a trophic cascade.

Science.gov (United States)

Walsh, Jake R; Carpenter, Stephen R; Vander Zanden, M Jake

2016-04-12

Despite growing recognition of the importance of ecosystem services and the economic and ecological harm caused by invasive species, linkages between invasions, changes in ecosystem functioning, and in turn, provisioning of ecosystem services remain poorly documented and poorly understood. We evaluate the economic impacts of an invasion that cascaded through a food web to cause substantial declines in water clarity, a valued ecosystem service. The predatory zooplankton, the spiny water flea (Bythotrephes longimanus), invaded the Laurentian Great Lakes in the 1980s and has subsequently undergone secondary spread to inland lakes, including Lake Mendota (Wisconsin), in 2009. In Lake Mendota, Bythotrephes has reached unparalleled densities compared with in other lakes, decreasing biomass of the grazer Daphnia pulicaria and causing a decline in water clarity of nearly 1 m. Time series modeling revealed that the loss in water clarity, valued at US$140 million (US$640 per household), could be reversed by a 71% reduction in phosphorus loading. A phosphorus reduction of this magnitude is estimated to cost between US$86.5 million and US$163 million (US$430-US$810 per household). Estimates of the economic effects of Great Lakes invasive species may increase considerably if cases of secondary invasions into inland lakes, such as Lake Mendota, are included. Furthermore, such extreme cases of economic damages call for increased investment in the prevention and control of invasive species to better maximize the economic benefits of such programs. Our results highlight the need to more fully incorporate ecosystem services into our analysis of invasive species impacts, management, and public policy.

Safe surgery: how accurate are we at predicting intra-operative blood loss?

LENUS (Irish Health Repository)

2012-02-01

Introduction Preoperative estimation of intra-operative blood loss by both anaesthetist and operating surgeon is a criterion of the World Health Organization\\'s surgical safety checklist. The checklist requires specific preoperative planning when anticipated blood loss is greater than 500 mL. The aim of this study was to assess the accuracy of surgeons and anaesthetists at predicting intra-operative blood loss. Methods A 6-week prospective study of intermediate and major operations in an academic medical centre was performed. An independent observer interviewed surgical and anaesthetic consultants and registrars, preoperatively asking each to predict expected blood loss in millilitre. Intra-operative blood loss was measured and compared with these predictions. Parameters including the use of anticoagulation and anti-platelet therapy as well as intra-operative hypothermia and hypotension were recorded. Results One hundred sixty-eight operations were included in the study, including 142 elective and 26 emergency operations. Blood loss was predicted to within 500 mL of measured blood loss in 89% of cases. Consultant surgeons tended to underestimate blood loss, doing so in 43% of all cases, while consultant anaesthetists were more likely to overestimate (60% of all operations). Twelve patients (7%) had underestimation of blood loss of more than 500 mL by both surgeon and anaesthetist. Thirty per cent (n = 6\\/20) of patients requiring transfusion of a blood product within 24 hours of surgery had blood loss underestimated by more than 500 mL by both surgeon and anaesthetist. There was no significant difference in prediction between patients on anti-platelet or anticoagulation therapy preoperatively and those not on the said therapies. Conclusion Predicted intra-operative blood loss was within 500 mL of measured blood loss in 89% of operations. In 30% of patients who ultimately receive a blood transfusion, both the surgeon and anaesthetist significantly underestimate

The effect of stressed economic conditions on operational risk loss distributions

Directory of Open Access Journals (Sweden)

Ja'nel Esterhuysen

2010-12-01

Full Text Available The depth and duration of the credit crisis has highlighted a number of problems in modern finance. Banks have been accused of excessive risk taking, rating agencies of severe conflicts of interest, central banks of neglecting the inflation of asset price bubbles and national supervisors of lax regulatory controls. Credit and market losses have been considerable. Operational losses have also surged as surviving corporates merge or acquire less fortunate ones without the requisite controls. Furthermore, as more jobs get made redundant it is believed that people are getting forced to play their hand to get involved in internal fraud as their sources of income has dried up drastically and stealing from the institution seems to be their last resort.. The main objective of this paper is to establish if there has been a changed in the nature of operational risk with regards to the number of operational losses as well as their impact pre and during the crisis. The way in which operational losses have been affected will be presented and a comparison will be made between operational loss characteristics pre and during the crisis. Some of the main findings of this paper were that operational losses shown little change in frequency, but shown a significant increase in severity, meaning that their financial impact has been more severe during the crisis.  Therefore it is quite safe to say that the financial crisis most defiantly had an impact on operational risk as the impact of operational losses became much more severe

Crop production and economic loss due to wind erosion in hot arid ecosystem of India

Science.gov (United States)

Santra, Priyabrata; Moharana, P. C.; Kumar, Mahesh; Soni, M. L.; Pandey, C. B.; Chaudhari, S. K.; Sikka, A. K.

2017-10-01

Wind erosion is a severe land degradation process in hot arid western India and affects the agricultural production system. It affects crop yield directly by damaging the crops through abrasion, burial, dust deposition etc. and indirectly by reducing soil fertility. In this study, an attempt was made to quantify the indirect impact of wind erosion process on crop production loss and associated economic loss in hot arid ecosystem of India. It has been observed that soil loss due to wind erosion varies from minimum 1.3 t ha-1 to maximum 83.3 t ha-1 as per the severity. Yield loss due to wind erosion was found maximum for groundnut (Arachis hypogea) (5-331 kg ha-1 yr-1), whereas minimum for moth bean (Vigna aconitifolia) (1-93 kg ha-1 yr-1). For pearl millet (Pennisetum glaucum), which covers a major portion of arable lands in western Rajasthan, the yield loss was found 3-195 kg ha-1 yr-1. Economic loss was found higher for groundnut and clusterbean (Cyamopsis tetragonoloba) than rest crops, which are about

26 CFR 1.1502-21T - Net operating losses (temporary).

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 12 2010-04-01 2010-04-01 false Net operating losses (temporary). 1.1502-21T...) INCOME TAX (CONTINUED) INCOME TAXES Computation of Consolidated Items § 1.1502-21T Net operating losses...)(B). (C) Partial waiver of carryback period for 2001 and 2002 losses—(1) Application. The acquiring...

26 CFR 1.172-10 - Net operating losses of real estate investment trusts.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 3 2010-04-01 2010-04-01 false Net operating losses of real estate investment... (continued) § 1.172-10 Net operating losses of real estate investment trusts. (a) Taxable years to which a loss may be carried. (1) A net operating loss sustained by a qualified real estate investment trust (as...

Photochemically induced carbon dioxide production as a mechanism for carbon loss from plant litter in arid ecosystems

Science.gov (United States)

Brandt, L. A.; Bohnet, C.; King, J. Y.

2009-06-01

We investigated the potential for abiotic mineralization to carbon dioxide (CO2) via photodegradation to account for carbon (C) loss from plant litter under conditions typical of arid ecosystems. We exposed five species of grass and oak litter collected from arid and mesic sites to a factorial design of ultraviolet (UV) radiation (UV pass, UV block), and sterilization under dry conditions in the laboratory. UV pass treatments produced 10 times the amount of CO2 produced in UV block treatments. CO2 production rates were unaffected by litter chemistry or sterilization. We also exposed litter to natural solar radiation outdoors on clear, sunny days close to the summer solstice at midlatitudes and found that UV radiation (280-400 nm) accounted for 55% of photochemically induced CO2 production, while shortwave visible radiation (400-500 nm) accounted for 45% of CO2 production. Rates of photochemically induced CO2 production on a per-unit-mass basis decreased with litter density, indicating that rates depend on litter surface area. We found no evidence for leaching, methane production, or facilitation of microbial decomposition as alternative mechanisms for significant photochemically induced C loss from litter. We conclude that abiotic mineralization to CO2 is the primary mechanism by which C is lost from litter during photodegradation. We estimate that CO2 production via photodegradation could be between 1 and 4 g C m-2 a-1 in arid ecosystems in the southwestern United States. Taken together with low levels of litter production in arid systems, photochemical mineralization to CO2 could account for a significant proportion of annual carbon loss from litter in arid ecosystems.

Making the ecosystem approach operational-Can regime shifts in ecological- and governance systems facilitate the transition?

DEFF Research Database (Denmark)

Österblom, H.; Gårdmark, A.; Bergström, L.

2010-01-01

Effectively reducing cumulative impacts on marine ecosystems requires co-evolution between science, policy and practice. Here, long-term social–ecological changes in the Baltic Sea are described, illustrating how the process of making the ecosystem approach operational in a large marine ecosystem...... stimulating innovations and re-organizing governance structures at drainage basin level to the Baltic Sea catchment as a whole. Experimentation and innovation at local to the regional levels is critical for a transition to ecosystem-based management. Establishing science-based learning platforms at sub...

Radial oxygen loss from roots of Vallisneria spiralis L.: biogeochemical implications in eutrophic aquatic ecosystems

OpenAIRE

Soana, Elisa

2013-01-01

Eutrophication and the accumulation of organic matter have been addressed as the major factors determining the decline of benthic vegetation in impacted water bodies and the consequent loss of key ecosystemic functions. In freshwater environments the literature reports submersed macrophyte die-back events and the switch to free-floating and floating-leaved plants dominated states. Species-specific differences in macrophyte response along organic gradients are evident. Some species have develo...

Mapping potential carbon and timber losses from hurricanes using a decision tree and ecosystem services driver model.

Science.gov (United States)

Delphin, S; Escobedo, F J; Abd-Elrahman, A; Cropper, W

2013-11-15

Information on the effect of direct drivers such as hurricanes on ecosystem services is relevant to landowners and policy makers due to predicted effects from climate change. We identified forest damage risk zones due to hurricanes and estimated the potential loss of 2 key ecosystem services: aboveground carbon storage and timber volume. Using land cover, plot-level forest inventory data, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, and a decision tree-based framework; we determined potential damage to subtropical forests from hurricanes in the Lower Suwannee River (LS) and Pensacola Bay (PB) watersheds in Florida, US. We used biophysical factors identified in previous studies as being influential in forest damage in our decision tree and hurricane wind risk maps. Results show that 31% and 0.5% of the total aboveground carbon storage in the LS and PB, respectively was located in high forest damage risk (HR) zones. Overall 15% and 0.7% of the total timber net volume in the LS and PB, respectively, was in HR zones. This model can also be used for identifying timber salvage areas, developing ecosystem service provision and management scenarios, and assessing the effect of other drivers on ecosystem services and goods. Copyright © 2013 Elsevier Ltd. All rights reserved.

Decommissioning and reclamation of the Beaverlodge uranium mine/mill operation: ecosystem in recovery

International Nuclear Information System (INIS)

Himbeault, K.; Phillips, R.L.J.; Vanriel, P.; Wells, K.; Halbert, B.E.

2006-01-01

The Beaverlodge uranium mining and milling facility, located near Uranium City in northern Saskatchewan, operated for a period of thirty-two years between 1950 and 1982, making it one of the longest operating facilities of its type in Canada. Ore was extracted from the ma in underground mine and from smaller underground and open pit satellite deposits in a ratio of 94% and 6% respectively. Decommissioning activities consisted of four phases, shutdown, salvage and reclamation which occurred from 1982-1985, and the current transition monitoring phase from 1985 to present. Following transition monitoring to prove that the system is behaving as expected, licence revocation and hence completion of decommissioning is expected to occur. The plan to achieve delicensing from the federal Canadian Nuclear Safety Commission and surface lease revocation from the provincial government is currently captured in a 10-year plan, 2003-2013. The main remaining objective of the decommissioning plan is to document the aquatic ecosystem recovery of the former tailings management facility (TMF), which consisted of two natural lakes, and of the two former underground satellite areas, Hab and Dubyna. Extensive environmental monitoring has been carried out in the receiving environment, Beaverlodge Lake, the former Dubyna mine area and the TMF. Recovery of the aquatic ecosystems is occurring within an environment containing above-background levels of natural radionuclides. This makes Beaverlodge, with its relatively clean ore and long history of natural recovery, one of the better places to study low-level radioactive environmental biological effects. The Dubyna area has above background uranium concentrations in the water, sediment and fish, and a benthic invertebrate community similar to reference. In the receiving environment, Beaverlodge Lake, metal concentrations are highest with the deeper sediment. This trend fits well with the increased impacts of 32-years of operation followed by

20 CFR 404.1085 - Net operating loss deduction.

Science.gov (United States)

2010-04-01

... DISABILITY INSURANCE (1950- ) Employment, Wages, Self-Employment, and Self-Employment Income Self-Employment Income § 404.1085 Net operating loss deduction. When determining your net earnings from self-employment...

Loss of ecosystem services due to chronic pollution of forests and surface waters in the Adirondack region (USA)

Science.gov (United States)

Beier, Colin M.; Caputo, Jesse; Lawrence, Gregory B.; Sullivan, Timothy J.

2017-01-01

Sustaining recent progress in mitigating acid pollution could require lower emissions caps that will give rise to real or perceived tradeoffs between healthy ecosystems and inexpensive energy. Because most impacts of acid rain affect ecosystem functions that are poorly understood by policy-makers and the public, an ecosystem services (ES) framework can help to measure how pollution affects human well-being. Focused on the Adirondack region (USA), a global ‘hot-spot’ of acid pollution, we measured how the chronic acidification of the region's forests, lakes, and streams has affected the potential economic and cultural benefits they provide to society. We estimated that acid-impaired hardwood forests provide roughly half of the potential benefits of forests on moderate to well-buffered soils – an estimated loss of ∼ $10,000 ha−1 in net present value of wood products, maple syrup, carbon sequestration, and visual quality. Acidic deposition has had only nominal impact – relative to the effects of surficial geology and till depth – on the capacity of Adirondack lakes and streams to provide water suitable for drinking. However, as pH declines in lakes, the estimated value of recreational fishing decreases significantly due to loss of desirable fish such as trout. Hatchery stocking programs have partially offset the pollution-mediated losses of fishery value, most effectively in the pH range 4.8–5.5, but are costly and limited in scope. Although any estimates of the monetary ‘damages’ of acid rain have significant uncertainties, our findings highlight some of the more tangible economic and cultural benefits of pollution mitigation efforts, which continue to face litigation and political opposition.

An evaluation of intra-operative and post-operative blood loss in ...

African Journals Online (AJOL)

Background: Total knee replacement is a rewarding and reliable procedure, producing a lasting relief to severe knee pains. However, significant blood loss usually in the post-operative period may be a challenge, necessitating prompt restoration of circulating blood volume to minimize morbidity and mortality. The aim of this ...

Predicting operative blood loss during spinal fusion for adolescent idiopathic scoliosis.

Science.gov (United States)

Ialenti, Marc N; Lonner, Baron S; Verma, Kushagra; Dean, Laura; Valdevit, Antonio; Errico, Thomas

2013-06-01

Patient and surgical factors are known to influence operative blood loss in spinal fusion for adolescent idiopathic scoliosis (AIS), but have only been loosely identified. To date, there are no established recommendations to guide decisions to predonate autologous blood, and the current practice is based primarily on surgeon preference. This study is designed to determine which patient and surgical factors are correlated with, and predictive of, blood loss during spinal fusion for AIS. Retrospective analysis of 340 (81 males, 259 females; mean age, 15.2 y) consecutive AIS patients treated by a single surgeon from 2000 to 2008. Demographic (sex, age, height, weight, and associated comorbidities), laboratory (hematocrit, platelet, PT/PTT/INR), standard radiographic, and perioperative data including complications were analyzed with a linear stepwise regression to develop a predictive model of blood loss. Estimated blood loss was 907±775 mL for posterior spinal fusion (PSF, n=188), 323±171 mL for anterior spinal fusion (ASF, n=124), and 1277±821 mL for combined procedures (n=28). For patients undergoing PSF, stepwise analysis identified sex, preoperative kyphosis, and operative time to be the most important predictors of increased blood loss (Ploss in PSF: blood loss (mL)=C+Op-time (min)×(6.4)-pre-op T2-T12 kyphosis (degrees)×(8.7), C=233 if male and -270 if female. We find sex, operative time, and preoperative kyphosis to be the most important predictors of increased blood loss in PSF for AIS. Mean arterial pressure and operative time were predictive of estimated blood loss in ASF. For posterior fusions, we also present a model that estimates blood loss preoperatively and can be used to guide decisions regarding predonation of blood and the use of antifibrinolytic agents. Retrospective study: Level II.

Crate counter for normal operating loss

International Nuclear Information System (INIS)

Harlan, R.A.

A lithium-loaded zinc sulfide scintillation counter to closely assay plutonium in waste packaged in 1.3 by 1.3 by 2.13m crates was built. In addition to assays for normal operating loss accounting, the counter will allow safeguards verification immediately before shipment of the crates for burial. The counter should detect approximately 10 g of plutonium in 1000 kg of waste

Metal losses in pyrometallurgical operations - A review.

Science.gov (United States)

Bellemans, Inge; De Wilde, Evelien; Moelans, Nele; Verbeken, Kim

2018-05-01

Nowadays, a higher demand on a lot of metals exists, but the quantity and purity of the ores decreases. The amount of scrap, on the other hand, increases and thus, recycling becomes more important. Besides recycling, it is also necessary to improve and optimize existing processes in extractive and recycling metallurgy. One of the main difficulties of the overall-plant recovery are metal losses in slags, in both primary and secondary metal production. In general, an increased understanding of the fundamental mechanisms governing these losses could help further improve production efficiencies. This review aims to summarize and evaluate the current scientific knowledge concerning metal losses and pinpoints the knowledge gaps. First, the industrial importance and impact of metal losses in slags will be illustrated by several examples from both ferrous and non-ferrous industries. Throughout the remainder of this review, the main focus will be put on the particular issues in copper industry. In a second section, the different types of metal losses in slags will be discussed. Generally, metal losses in slags can be subdivided into two types: chemical losses and physical losses. The fundamental insights concerning the responsible mechanisms will be discussed for each type. Subsequently, an overview of the most frequently used techniques for research investigations of the losses will be given. In a fourth section, a more detailed overview will be given on the post-processing treatment of metal-containing slags, i.e. performing slag cleaning operations. The most frequently applied methods will be discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Recognizing loss of open forest ecosystems by tree densification and land use intensification in the Midwestern USA

Science.gov (United States)

Brice B. Hanberry; Marc D. Abrams

2018-01-01

Forests and grasslands have changed during the past 200 years in the eastern USA, and it is now possible to quantify loss and conversion of vegetation cover at regional scales. We quantified historical (ca. 1786-1908) and current land cover and determined long-term ecosystem change to either land use or closed forests in eight states of the Great Lakes and Midwest....

Interacting Factors Driving a Major Loss of Large Trees with Cavities in a Forest Ecosystem

Science.gov (United States)

Lindenmayer, David B.; Blanchard, Wade; McBurney, Lachlan; Blair, David; Banks, Sam; Likens, Gene E.; Franklin, Jerry F.; Laurance, William F.; Stein, John A. R.; Gibbons, Philip

2012-01-01

Large trees with cavities provide critical ecological functions in forests worldwide, including vital nesting and denning resources for many species. However, many ecosystems are experiencing increasingly rapid loss of large trees or a failure to recruit new large trees or both. We quantify this problem in a globally iconic ecosystem in southeastern Australia – forests dominated by the world's tallest angiosperms, Mountain Ash (Eucalyptus regnans). Tree, stand and landscape-level factors influencing the death and collapse of large living cavity trees and the decay and collapse of dead trees with cavities are documented using a suite of long-term datasets gathered between 1983 and 2011. The historical rate of tree mortality on unburned sites between 1997 and 2011 was >14% with a mortality spike in the driest period (2006–2009). Following a major wildfire in 2009, 79% of large living trees with cavities died and 57–100% of large dead trees were destroyed on burned sites. Repeated measurements between 1997 and 2011 revealed no recruitment of any new large trees with cavities on any of our unburned or burned sites. Transition probability matrices of large trees with cavities through increasingly decayed condition states projects a severe shortage of large trees with cavities by 2039 that will continue until at least 2067. This large cavity tree crisis in Mountain Ash forests is a product of: (1) the prolonged time required (>120 years) for initiation of cavities; and (2) repeated past wildfires and widespread logging operations. These latter factors have resulted in all landscapes being dominated by stands ≤72 years and just 1.16% of forest being unburned and unlogged. We discuss how the features that make Mountain Ash forests vulnerable to a decline in large tree abundance are shared with many forest types worldwide. PMID:23071486

Interacting factors driving a major loss of large trees with cavities in a forest ecosystem.

Directory of Open Access Journals (Sweden)

David B Lindenmayer

Full Text Available Large trees with cavities provide critical ecological functions in forests worldwide, including vital nesting and denning resources for many species. However, many ecosystems are experiencing increasingly rapid loss of large trees or a failure to recruit new large trees or both. We quantify this problem in a globally iconic ecosystem in southeastern Australia--forests dominated by the world's tallest angiosperms, Mountain Ash (Eucalyptus regnans. Tree, stand and landscape-level factors influencing the death and collapse of large living cavity trees and the decay and collapse of dead trees with cavities are documented using a suite of long-term datasets gathered between 1983 and 2011. The historical rate of tree mortality on unburned sites between 1997 and 2011 was >14% with a mortality spike in the driest period (2006-2009. Following a major wildfire in 2009, 79% of large living trees with cavities died and 57-100% of large dead trees were destroyed on burned sites. Repeated measurements between 1997 and 2011 revealed no recruitment of any new large trees with cavities on any of our unburned or burned sites. Transition probability matrices of large trees with cavities through increasingly decayed condition states projects a severe shortage of large trees with cavities by 2039 that will continue until at least 2067. This large cavity tree crisis in Mountain Ash forests is a product of: (1 the prolonged time required (>120 years for initiation of cavities; and (2 repeated past wildfires and widespread logging operations. These latter factors have resulted in all landscapes being dominated by stands ≤72 years and just 1.16% of forest being unburned and unlogged. We discuss how the features that make Mountain Ash forests vulnerable to a decline in large tree abundance are shared with many forest types worldwide.

Interacting factors driving a major loss of large trees with cavities in a forest ecosystem.

Science.gov (United States)

Lindenmayer, David B; Blanchard, Wade; McBurney, Lachlan; Blair, David; Banks, Sam; Likens, Gene E; Franklin, Jerry F; Laurance, William F; Stein, John A R; Gibbons, Philip

2012-01-01

Large trees with cavities provide critical ecological functions in forests worldwide, including vital nesting and denning resources for many species. However, many ecosystems are experiencing increasingly rapid loss of large trees or a failure to recruit new large trees or both. We quantify this problem in a globally iconic ecosystem in southeastern Australia--forests dominated by the world's tallest angiosperms, Mountain Ash (Eucalyptus regnans). Tree, stand and landscape-level factors influencing the death and collapse of large living cavity trees and the decay and collapse of dead trees with cavities are documented using a suite of long-term datasets gathered between 1983 and 2011. The historical rate of tree mortality on unburned sites between 1997 and 2011 was >14% with a mortality spike in the driest period (2006-2009). Following a major wildfire in 2009, 79% of large living trees with cavities died and 57-100% of large dead trees were destroyed on burned sites. Repeated measurements between 1997 and 2011 revealed no recruitment of any new large trees with cavities on any of our unburned or burned sites. Transition probability matrices of large trees with cavities through increasingly decayed condition states projects a severe shortage of large trees with cavities by 2039 that will continue until at least 2067. This large cavity tree crisis in Mountain Ash forests is a product of: (1) the prolonged time required (>120 years) for initiation of cavities; and (2) repeated past wildfires and widespread logging operations. These latter factors have resulted in all landscapes being dominated by stands ≤72 years and just 1.16% of forest being unburned and unlogged. We discuss how the features that make Mountain Ash forests vulnerable to a decline in large tree abundance are shared with many forest types worldwide.

Loss of ecosystem services due to chronic pollution of forests and surface waters in the Adirondack region (USA).

Science.gov (United States)

Beier, Colin M; Caputo, Jesse; Lawrence, Gregory B; Sullivan, Timothy J

2017-04-15

Sustaining recent progress in mitigating acid pollution could require lower emissions caps that will give rise to real or perceived tradeoffs between healthy ecosystems and inexpensive energy. Because most impacts of acid rain affect ecosystem functions that are poorly understood by policy-makers and the public, an ecosystem services (ES) framework can help to measure how pollution affects human well-being. Focused on the Adirondack region (USA), a global 'hot-spot' of acid pollution, we measured how the chronic acidification of the region's forests, lakes, and streams has affected the potential economic and cultural benefits they provide to society. We estimated that acid-impaired hardwood forests provide roughly half of the potential benefits of forests on moderate to well-buffered soils - an estimated loss of ∼ $10,000 ha -1 in net present value of wood products, maple syrup, carbon sequestration, and visual quality. Acidic deposition has had only nominal impact - relative to the effects of surficial geology and till depth - on the capacity of Adirondack lakes and streams to provide water suitable for drinking. However, as pH declines in lakes, the estimated value of recreational fishing decreases significantly due to loss of desirable fish such as trout. Hatchery stocking programs have partially offset the pollution-mediated losses of fishery value, most effectively in the pH range 4.8-5.5, but are costly and limited in scope. Although any estimates of the monetary 'damages' of acid rain have significant uncertainties, our findings highlight some of the more tangible economic and cultural benefits of pollution mitigation efforts, which continue to face litigation and political opposition. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Global Trend towards the Loss of Evolutionarily Unique Species in Mangrove Ecosystems.

Directory of Open Access Journals (Sweden)

Barnabas H Daru

Full Text Available The mangrove biome stands out as a distinct forest type at the interface between terrestrial, estuarine, and near-shore marine ecosystems. However, mangrove species are increasingly threatened and experiencing range contraction across the globe that requires urgent conservation action. Here, we assess the spatial distribution of mangrove species richness and evolutionary diversity, and evaluate potential predictors of global declines and risk of extinction. We found that human pressure, measured as the number of different uses associated with mangroves, correlated strongly, but negatively, with extinction probability, whereas species ages were the best predictor of global decline, explaining 15% of variation in extinction risk. Although the majority of mangrove species are categorised by the IUCN as Least Concern, our finding that the more threatened species also tend to be those that are more evolutionarily unique is of concern because their extinction would result in a greater loss of phylogenetic diversity. Finally, we identified biogeographic regions that are relatively species-poor but rich in evolutionary history, and suggest these regions deserve greater conservation priority. Our study provides phylogenetic information that is important for developing a unified management plan for mangrove ecosystems worldwide.

A Global Trend towards the Loss of Evolutionarily Unique Species in Mangrove Ecosystems.

Science.gov (United States)

Daru, Barnabas H; Yessoufou, Kowiyou; Mankga, Ledile T; Davies, T Jonathan

2013-01-01

The mangrove biome stands out as a distinct forest type at the interface between terrestrial, estuarine, and near-shore marine ecosystems. However, mangrove species are increasingly threatened and experiencing range contraction across the globe that requires urgent conservation action. Here, we assess the spatial distribution of mangrove species richness and evolutionary diversity, and evaluate potential predictors of global declines and risk of extinction. We found that human pressure, measured as the number of different uses associated with mangroves, correlated strongly, but negatively, with extinction probability, whereas species ages were the best predictor of global decline, explaining 15% of variation in extinction risk. Although the majority of mangrove species are categorised by the IUCN as Least Concern, our finding that the more threatened species also tend to be those that are more evolutionarily unique is of concern because their extinction would result in a greater loss of phylogenetic diversity. Finally, we identified biogeographic regions that are relatively species-poor but rich in evolutionary history, and suggest these regions deserve greater conservation priority. Our study provides phylogenetic information that is important for developing a unified management plan for mangrove ecosystems worldwide.

Mapping wetland loss and restoration potential in Flanders (Belgium: an ecosystem service perspective

Directory of Open Access Journals (Sweden)

Kris Decleer

2016-12-01

Full Text Available With the case of Flanders (northern part of Belgium we present an integrated approach to calculate accurate losses of wetlands, potentials for restoration, and their ecosystem services supplies and illustrate how these insights can be used to evaluate and support policy making. Flanders lost about 75% of its wetland habitats in the past 50-60 years, with currently only 68,000 ha remaining, often in a more or less degraded state. For five different wetland categories (excluding open waters we calculated that restoration of lost wetland is still possible for an additional total area of about 147,000 ha, assuming that, with time and appropriate measures and techniques, the necessary biophysical and ecological conditions can more or less be restored or created. Wetland restoration opportunities were mapped according to an open and forested landscape scenario. Despite the fact that for 49,000 ha wetland restoration is justifiable by the actual presence of an appropriate spatial planning and/or protection status, the official Flemish nature policy only foresees 7,400 to 10,600 ha of additional wetland (open waters excluded by 2050. The benefits of a more ambitious wetland restoration action program are underpinned by an explorative and quantified analysis of ecosystem service supply for each of the two scenarios, showing that the strongly increased supply of several important regulating and cultural ecosystem services might outweigh the decrease of food production, especially if extensive farming on temporary wet soils remains possible. Finally, we discuss the challenges of wetland restoration policies for biodiversity conservation and climate change.

An empirical study to measure the effects of various factors on operating loss

Directory of Open Access Journals (Sweden)

Saeeid Khodaei Valahzaghard

2012-10-01

Full Text Available In this paper, we present an empirical investigation to measure the effects of various factors on operating loss in one of major Iranian banks called Bank Mellat. The proposed study of this paper uses a standard questionnaire and distributes it among 57 people who are mainly in top management levels. The questions are categorized into five groups including events related to the processes and methods, events outside the organization, related events within the organization and business disruptions and system failure. The results of our survey confirm that the loss associated with events related to the processes and methods increases operating risk meaningfully, the loss associated with business disruptions and system failure increases operating risk meaningfully and the loss associated with related events within the organization increases operating risk meaningfully. However, our survey do not confirm that the loss associated with events outside the organization increase operating, risk meaningfully. Finally, the preliminary survey of our analysis shows that there is not enough evidence to believe that the effects of business disruption and internal affairs are significantly different from the other event.

The loss of ecosystem services due to land degradation. Integration of mechanistic and probabilistic models in an Ethiopian case study

Science.gov (United States)

Cerretelli, Stefania; Poggio, Laura; Gimona, Alessandro; Peressotti, Alessandro; Black, Helaina

2017-04-01

Land and soil degradation are widespread especially in dry and developing countries such as Ethiopia. Land degradation leads to ecosystems services (ESS) degradation, because it causes the depletion and loss of several soil functions. Ethiopia's farmland faces intense degradation due to deforestation, agricultural land expansion, land overexploitation and overgrazing. In this study we modelled the impact of physical factors on ESS degradation, in particular soil erodibility, carbon storage and nutrient retention, in the Ethiopian Great Rift Valley, northwestern of Hawassa. We used models of the Sediment retention/loss, the Nutrient Retention/loss (from the software suite InVEST) and Carbon Storage. To run the models we coupled soil local data (such as soil organic carbon, soil texture) with remote sensing data as input in the parametrization phase, e.g. to derive a land use map, to calculate the aboveground and belowground carbon, the evapotraspiration coefficient and the capacity of vegetation to retain nutrient. We then used spatialised Bayesian Belief Networks (sBBNs) predicting ecosystem services degradation on the basis of the results of the three mechanistic models. The results show i) the importance of mapping of ESS degradation taking into consideration the spatial heterogeneity and the cross-correlations between impacts ii) the fundamental role of remote sensing data in monitoring and modelling in remote, data-poor areas and iii) the important role of spatial BBNs in providing spatially explicit measures of risk and uncertainty. This approach could help decision makers to identify priority areas for intervention in order to reduce land and ecosystem services degradation.

Soil biodiversity and soil community composition determine ecosystem multifunctionality

Science.gov (United States)

Wagg, Cameron; Bender, S. Franz; Widmer, Franco; van der Heijden, Marcel G. A.

2014-01-01

Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth’s biodiversity is literally hidden below ground. Whether reductions of biodiversity in soil communities below ground have consequences for the overall performance of an ecosystem remains unresolved. It is important to investigate this in view of recent observations that soil biodiversity is declining and that soil communities are changing upon land use intensification. We established soil communities differing in composition and diversity and tested their impact on eight ecosystem functions in model grassland communities. We show that soil biodiversity loss and simplification of soil community composition impair multiple ecosystem functions, including plant diversity, decomposition, nutrient retention, and nutrient cycling. The average response of all measured ecosystem functions (ecosystem multifunctionality) exhibited a strong positive linear relationship to indicators of soil biodiversity, suggesting that soil community composition is a key factor in regulating ecosystem functioning. Our results indicate that changes in soil communities and the loss of soil biodiversity threaten ecosystem multifunctionality and sustainability. PMID:24639507

The comparison of placental removal methods on operative blood loss

International Nuclear Information System (INIS)

Waqar, F.; Fawad, A.

2008-01-01

On an average 1 litre of blood is lost during Caesarean Section. Many variable techniques have been tried to reduce this blood loss. Many study trials have shown the spontaneous delivery of placenta method to be superior over manual method because of reduced intra operative blood loss and reduced incidence of post operative endometritis. The main objective of our study was to compare the risk of blood loss associated with spontaneous and manual removal of the placenta during caesarean section. This study was conducted at Department of Obstetrics and Gynaecology, Islamic International Medical Complex, Islamabad from September 2004 to September 2005. All Women undergoing elective or emergency caesarean section were included in the study. Exclusion criteria were pregnancy below 37 weeks, severe maternal anaemia, and prolonged rupture of the membranes with fever, placenta praevia, placenta accreta and clotting disorders. Patients were allocated to the two groups randomly. Group A comprised of women in whom the obstetrician waited a maximum of 5 minutes till the placenta delivered spontaneously. In group B the obstetrician manually cleaved out the placenta as soon as the infant was delivered. The primary outcome measures noted were difference in haemoglobin of >2 gm/dl (preoperatively and postoperatively), time interval between delivery of baby and placenta, significant blood loss (>1000 cc), additional use of oxytocics, total operating time and blood transfusions. Data was analysed by SPSS. Statistical tests used for specific comparison were chi square-test and Student's t-test. One hundred and forty-five patients were allocated to two groups randomly. Seventy-eight patients were allocated to group A and 67 patients allocated to group B. Mean maternal age, birth weight, and total operating time were the same in two groups, but blood loss as measured by a difference in haemoglobin of greater then 2 grams/dl was statistically significant. Significant blood loss (>1000 cc

International trade causes large net economic losses in tropical countries via the destruction of ecosystem services.

Science.gov (United States)

Chang, Junning; Symes, William S; Lim, Felix; Carrasco, L Roman

2016-05-01

Despite the large implications of the use of tropical land for exports ("land absorption") on ecosystem services (ES) and global biodiversity conservation, the magnitude of these externalities is not known. We quantify the net value of ES lost in tropical countries as a result of cropland, forestland and pastureland absorption for exports after deducting ES gains through imports ("land displacement"). We find that net ES gains occur only in 7 out of the 41 countries and regions considered. We estimate global annual net losses of over 1.7 x 10(12) international dollars (I$) (I$1.1 x 10(12) if carbon-related services are not considered). After deducting the benefits from agricultural, forest and livestock rents in land replacing tropical forests, the net annual losses are I$1.3 and I$0.7 x 10(12), respectively. The results highlight the large magnitude of tropical ES losses through international trade that are not compensated by the rents of land uses in absorbed land.

Valuing Ecosystem Services in Terms of Ecological Risks and Returns

DEFF Research Database (Denmark)

Abson, Dave; Termansen, Mette

2011-01-01

Abstract: The economic valuation of ecosystem services is a key policy tool in stemming losses of biological diversity. It is proposed that the loss of ecosystem function and the biological resources within ecosystems is due in part to the failure of markets to recognize the benefits humans derive...... from ecosystems. Placing monetary values on ecosystem services is often suggested as a necessary step in correcting such market failures. We consider the effects of valuing different types of ecosystem services within an economic framework. We argue that provisioning and regulating ecosystem services...

Modelling the ecosystem effects of nitrogen deposition: Model of Ecosystem Retention and Loss of Inorganic Nitrogen (MERLIN

Directory of Open Access Journals (Sweden)

B. J. Cosby

1997-01-01

Full Text Available A catchment-scale mass-balance model of linked carbon and nitrogen cycling in ecosystems has been developed for simulating leaching losses of inorganic nitrogen. The model (MERLIN considers linked biotic and abiotic processes affecting the cycling and storage of nitrogen. The model is aggregated in space and time and contains compartments intended to be observable and/or interpretable at the plot or catchment scale. The structure of the model includes the inorganic soil, a plant compartment and two soil organic compartments. Fluxes in and out of the ecosystem and between compartments are regulated by atmospheric deposition, hydrological discharge, plant uptake, litter production, wood production, microbial immobilization, mineralization, nitrification, and denitrification. Nitrogen fluxes are controlled by carbon productivity, the C:N ratios of organic compartments and inorganic nitrogen in soil solution. Inputs required are: 1 temporal sequences of carbon fluxes and pools- 2 time series of hydrological discharge through the soils, 3 historical and current external sources of inorganic nitrogen; 4 current amounts of nitrogen in the plant and soil organic compartments; 5 constants specifying the nitrogen uptake and immobilization characteristics of the plant and soil organic compartments; and 6 soil characteristics such as depth, porosity, bulk density, and anion/cation exchange constants. Outputs include: 1 concentrations and fluxes of NO3 and NH4 in soil solution and runoff; 2 total nitrogen contents of the organic and inorganic compartments; 3 C:N ratios of the aggregated plant and soil organic compartments; and 4 rates of nitrogen uptake and immobilization and nitrogen mineralization. The behaviour of the model is assessed for a combination of land-use change and nitrogen deposition scenarios in a series of speculative simulations. The results of the simulations are in broad agreement with observed and hypothesized behaviour of nitrogen

Indicators of biodiversity and ecosystem services: A synthesis across ecosystems and spatial scales

Science.gov (United States)

Feld, C.K.; Da Silva, P.M.; Sousa, J.P.; De Bello, F.; Bugter, R.; Grandin, U.; Hering, D.; Lavorel, S.; Mountford, O.; Pardo, I.; Partel, M.; Rombke, J.; Sandin, Leonard; Jones, K. Bruce; Harrison, P.

2009-01-01

According to the Millennium Ecosystem Assessment, common indicators are needed to monitor the loss of biodiversity and the implications for the sustainable provision of ecosystem services. However, a variety of indicators are already being used resulting in many, mostly incompatible, monitoring systems. In order to synthesise the different indicator approaches and to detect gaps in the development of common indicator systems, we examined 531 indicators that have been reported in 617 peer-reviewed journal articles between 1997 and 2007. Special emphasis was placed on comparing indicators of biodiversity and ecosystem services across ecosystems (forests, grass- and shrublands, wetlands, rivers, lakes, soils and agro-ecosystems) and spatial scales (from patch to global scale). The application of biological indicators was found most often focused on regional and finer spatial scales with few indicators applied across ecosystem types. Abiotic indicators, such as physico-chemical parameters and measures of area and fragmentation, are most frequently used at broader (regional to continental) scales. Despite its multiple dimensions, biodiversity is usually equated with species richness only. The functional, structural and genetic components of biodiversity are poorly addressed despite their potential value across habitats and scales. Ecosystem service indicators are mostly used to estimate regulating and supporting services but generally differ between ecosystem types as they reflect ecosystem-specific services. Despite great effort to develop indicator systems over the past decade, there is still a considerable gap in the widespread use of indicators for many of the multiple components of biodiversity and ecosystem services, and a need to develop common monitoring schemes within and across habitats. Filling these gaps is a prerequisite for linking biodiversity dynamics with ecosystem service delivery and to achieving the goals of global and sub-global initiatives to halt

Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

International Nuclear Information System (INIS)

Parsapour, Amir; Dehkordi, Behzad Mirzaeian; Moallem, Mehdi

2015-01-01

In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared. - Highlights: • Continuous current method for Switched Reluctance Motor (SRM) is explained. • An improved analytical technique is presented for SRM core loss calculation. • SRM losses in discontinuous and continuous current operation modes are presented. • Effect of mutual inductances on SRM performance is investigated

Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

Energy Technology Data Exchange (ETDEWEB)

Parsapour, Amir, E-mail: amirparsapour@gmail.com [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Dehkordi, Behzad Mirzaeian, E-mail: mirzaeian@eng.ui.ac.ir [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Moallem, Mehdi, E-mail: moallem@cc.iut.ac.ir [Department of Electrical Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

2015-03-15

In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared. - Highlights: • Continuous current method for Switched Reluctance Motor (SRM) is explained. • An improved analytical technique is presented for SRM core loss calculation. • SRM losses in discontinuous and continuous current operation modes are presented. • Effect of mutual inductances on SRM performance is investigated.

N-15 tracing helps explaining N leaching losses from contrasting forest ecosystems

Science.gov (United States)

Staelens, J.; Rütting, T.; Huygens, D.; Müller, C.; Verheyen, K.; Boeckx, P.

2009-04-01

Despite chronically enhanced nitrogen (N) deposition to forest ecosystems in Europe and NE America, considerable N retention by forests has been observed, reducing N leaching losses. Organic and mineral soil layers typically immobilize more N than the aboveground biomass, but it is unclear which factors determine N retention in forest ecoystems. However, this knowledge is crucial to assess the impact of changing anthropogenic N emissions on future N cycling and N loss of forests. For coniferous and deciduous forest stands at comparable sites, it is known that both N deposition onto the forest floor as well as N loss by leaching below the rooting zone are significantly higher in coniferous stands. In addition, the N loss in coniferous stands is often more enhanced than can be explained by the higher N input only. This suggests lower N retention by coniferous stands, and may be related to differences in litter and soil characteristics, microbial activity, and N uptake by plant roots. To test this hypothesis, we studied the effect of forest type on N retention using 15N tracing techniques: a field tracer experiment and a combination of in situ isotope pool dilution and a tracing model. The N dynamics were examined for two adjacent forest stands (pedunculate oak (Quercus robur L.) and Scots pine (Pinus sylvestris L.)) on a well-drained sandy soil and with a similar stand history, located in a region with high N deposition (Belgium). Input-output N budgets were established by quantifying atmospheric deposition and leaching below the rooting zone, and confirmed the above finding of higher N deposition and disproportionately higher N loss for the pine stand compared to the oak stand. First, the fate of inorganic N within the ecosystems was studied by spraying three pulses of dissolved 15N, either as ammonium or as nitrate, onto the forest floor in 12 plots of 25 m2. The organic and mineral soil layers, tree roots, soil water percolate, ferns, and tree foliage were sampled

26 CFR 1.1502-21A - Consolidated net operating loss deduction generally applicable for consolidated return years...

Science.gov (United States)

2010-04-01

... operating loss attributable to such member. (iii) Foreign expropriation losses. An election under section... expropriation loss) may be made for a consolidated return year only if the sum of the foreign expropriation... expropriation losses, or (b) the consolidated net operating loss. (3) Absorption rules. For purposes of...

Designer ecosystems

NARCIS (Netherlands)

Awasthi, Ashutosh; Singh, Kripal; O'Grady, Audrey; Courtney, Ronan; Kalra, Alok; Singh, Rana Pratap; Cerda Bolinches, Artemio; Steinberger, Yosef; Patra, D.D.

2016-01-01

Increase in human population is accelerating the rate of land use change, biodiversity loss and habitat degradation, triggering a serious threat to life supporting ecosystem services. Existing strategies for biological conservation remain insufficient to achieve a sustainable human-nature

Distribution of AC loss in a HTS magnet for SMES with different operating conditions

Energy Technology Data Exchange (ETDEWEB)

Xu, Y., E-mail: xuyinghust@163.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, R and D Center of Applied Superconductivity, Huazhong University of Science and Technology, Wuhan 430074 (China); Tang, Y.; Ren, L.; Jiao, F. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, R and D Center of Applied Superconductivity, Huazhong University of Science and Technology, Wuhan 430074 (China); Song, M.; Cao, K.; Wang, D. [Yunnan Electric Power Research Institute, Kunming City 650217 (China); Wang, L.; Dong, H. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, R and D Center of Applied Superconductivity, Huazhong University of Science and Technology, Wuhan 430074 (China)

2013-11-15

Highlights: •We present a model to calculate the distribution of AC loss for a storage magnet. •Comparative analysis of AC loss with different operating conditions has done. •The nonuniform distribution factor “d” is proposed to estimate the inhomogeneity of a storage magnet. •The model predicts the loss distribution and crucial areas which are suffering from the high AC loss. This is significant for the conduction-cooled structure design. -- Abstract: The AC loss induced in superconducting tape may affect the performance of a superconducting device applied to power system, such as transformer, cable, motor and even Superconducting Magnetic Energy Storage (SMES). The operating condition of SMES is changeable due to the need of compensation to the active or reactive power according to the demand of a power grid. In this paper, it is investigated that the distribution of AC loss for a storage magnet on different operating conditions, which is based on finite element method (FEM) and measured properties of BSCCO/Ag tapes. This analytical method can be used to optimize the SMES magnet.

Nitrogen and phosphorus limitation over long-term ecosystem development in terrestrial ecosystems.

Directory of Open Access Journals (Sweden)

Duncan N L Menge

Full Text Available Nutrient limitation to net primary production (NPP displays a diversity of patterns as ecosystems develop over a range of timescales. For example, some ecosystems transition from N limitation on young soils to P limitation on geologically old soils, whereas others appear to remain N limited. Under what conditions should N limitation and P limitation prevail? When do transitions between N and P limitation occur? We analyzed transient dynamics of multiple timescales in an ecosystem model to investigate these questions. Post-disturbance dynamics in our model are controlled by a cascade of rates, from plant uptake (very fast to litter turnover (fast to plant mortality (intermediate to plant-unavailable nutrient loss (slow to weathering (very slow. Young ecosystems are N limited when symbiotic N fixation (SNF is constrained and P weathering inputs are high relative to atmospheric N deposition and plant N:P demand, but P limited under opposite conditions. In the absence of SNF, N limitation is likely to worsen through succession (decades to centuries because P is mineralized faster than N. Over long timescales (centuries and longer this preferential P mineralization increases the N:P ratio of soil organic matter, leading to greater losses of plant-unavailable N versus P relative to plant N:P demand. These loss dynamics favor N limitation on older soils despite the rising organic matter N:P ratio. However, weathering depletion favors P limitation on older soils when continual P inputs (e.g., dust deposition are low, so nutrient limitation at the terminal equilibrium depends on the balance of these input and loss effects. If NPP switches from N to P limitation over long time periods, the transition time depends most strongly on the P weathering rate. At all timescales SNF has the capacity to overcome N limitation, so nutrient limitation depends critically on limits to SNF.

Fishing for ecosystem services.

Science.gov (United States)

Pope, Kevin L; Pegg, Mark A; Cole, Nicholas W; Siddons, Stephen F; Fedele, Alexis D; Harmon, Brian S; Ruskamp, Ryan L; Turner, Dylan R; Uerling, Caleb C

2016-12-01

Ecosystems are commonly exploited and manipulated to maximize certain human benefits. Such changes can degrade systems, leading to cascading negative effects that may be initially undetected, yet ultimately result in a reduction, or complete loss, of certain valuable ecosystem services. Ecosystem-based management is intended to maintain ecosystem quality and minimize the risk of irreversible change to natural assemblages of species and to ecosystem processes while obtaining and maintaining long-term socioeconomic benefits. We discuss policy decisions in fishery management related to commonly manipulated environments with a focus on influences to ecosystem services. By focusing on broader scales, managing for ecosystem services, and taking a more proactive approach, we expect sustainable, quality fisheries that are resilient to future disturbances. To that end, we contend that: (1) management always involves tradeoffs; (2) explicit management of fisheries for ecosystem services could facilitate a transition from reactive to proactive management; and (3) adaptive co-management is a process that could enhance management for ecosystem services. We propose adaptive co-management with an ecosystem service framework where actions are implemented within ecosystem boundaries, rather than political boundaries, through strong interjurisdictional relationships. Published by Elsevier Ltd.

Observations of bunch-by-bunch losses in the 2010 LHC proton physics operation

CERN Document Server

Papotti, G

2011-01-01

This document summarizes the bunch-by-bunch loss observations carried out during the 2010 proton physics run at the LHC. These observations proved beneficial to the improvement of operations, in particular in the early days of nominal intensity per bunch operation: then the plots initiated the removal of the tune split and motivated the modification of a filling scheme to remove parasitic encounters that heightened the losses on selected bunches. Along with plots from sample physics fills, summary plots for the year are shown. The colour coding is always chosen so to highlight the dependence of the losses on the filling scheme.

Ecosystem Management. A Management View

DEFF Research Database (Denmark)

Ravn-Jonsen, Lars

The need for management of the marine ecosystem using a broad perspective has been recommended under a variety of names. This paper uses the term Ecosystem Management, which is seen as a convergence between the ecological idea of an organisational hierarchy and the idea of strategic planning...... with a planning hierarchy---with the ecosystem being the strategic planning level. Management planning requires, in order to establish a quantifiable means and ends chain, that the goals at the ecosystem level can be linked to operational levels; ecosystem properties must therefore be reducible to lower...... organisational levels. Emergence caused by constraints at both the component and system levels gives rise to phenomena that can create links between the ecosystem and operational levels. To create these links, the ecosystem's functional elements must be grouped according to their functionality, ignoring any...

Commissioning and operational scenarios of the LHC beam loss monitor system

International Nuclear Information System (INIS)

Holzer, E.B.

2007-01-01

One of the most critical elements for the protection of CERN's Large Hadron Collider (LHC) is its beam loss monitoring (BLM) system. It must prevent quenches in the super conducting magnets and damage of machine components due to beam losses. The contribution will discuss the commissioning procedures of the BLM system and envisaged operational scenarios. About 4000 monitors will be installed around the ring. When the loss rate exceeds a predefined threshold value, a beam abort is requested. Magnet quench and damage levels vary as a function of beam energy and loss duration. Consequently, the beam abort threshold values vary accordingly. By measuring the loss pattern, the BLM system helps to identify the loss mechanism. Furthermore, it will be an important tool for commissioning, machine setup and studies. Special monitors will be used for the setup and control of the collimators. (author)

Adaptive management for soil ecosystem services

Science.gov (United States)

Birge, Hannah E.; Bevans, Rebecca A.; Allen, Craig R.; Angeler, David G.; Baer, Sara G.; Wall, Diana H.

2016-01-01

Ecosystem services provided by soil include regulation of the atmosphere and climate, primary (including agricultural) production, waste processing, decomposition, nutrient conservation, water purification, erosion control, medical resources, pest control, and disease mitigation. The simultaneous production of these multiple services arises from complex interactions among diverse aboveground and belowground communities across multiple scales. When a system is mismanaged, non-linear and persistent losses in ecosystem services can arise. Adaptive management is an approach to management designed to reduce uncertainty as management proceeds. By developing alternative hypotheses, testing these hypotheses and adjusting management in response to outcomes, managers can probe dynamic mechanistic relationships among aboveground and belowground soil system components. In doing so, soil ecosystem services can be preserved and critical ecological thresholds avoided. Here, we present an adaptive management framework designed to reduce uncertainty surrounding the soil system, even when soil ecosystem services production is not the explicit management objective, so that managers can reach their management goals without undermining soil multifunctionality or contributing to an irreversible loss of soil ecosystem services.

Benthic algae compensate for phytoplankton losses in large aquatic ecosystems.

Science.gov (United States)

Brothers, Soren; Vadeboncoeur, Yvonne; Sibley, Paul

2016-12-01

Anthropogenic activities can induce major trophic shifts in aquatic systems, yet we have an incomplete understanding of the implication of such shifts on ecosystem function and on primary production (PP) in particular. In recent decades, phytoplankton biomass and production in the Laurentian Great Lakes have declined in response to reduced nutrient concentrations and invasive mussels. However, the increases in water clarity associated with declines in phytoplankton may have positive effects on benthic PP at the ecosystem scale. Have these lakes experienced oligotrophication (a reduction of algal production), or simply a shift in autotrophic structure with no net decline in PP? Benthic contributions to ecosystem PP are rarely measured in large aquatic systems, but our calculations based on productivity rates from the Great Lakes indicate that a significant proportion (up to one half, in Lake Huron) of their whole-lake production may be benthic. The large declines (5-45%) in phytoplankton production in the Great Lakes from the 1970s to 2000s may be substantially compensated by benthic PP, which increased by up to 190%. Thus, the autotrophic productive capacity of large aquatic ecosystems may be relatively resilient to shifts in trophic status, due to a redirection of production to the near-shore benthic zone, and large lakes may exhibit shifts in autotrophic structure analogous to the regime shifts seen in shallow lakes. © 2016 John Wiley & Sons Ltd.

Ecosystem approach in education

Science.gov (United States)

Nabiullin, Iskander

2017-04-01

Environmental education is a base for sustainable development. Therefore, in our school we pay great attention to environmental education. Environmental education in our school is based on ecosystem approach. What is an ecosystem approach? Ecosystem is a fundamental concept of ecology. Living organisms and their non-living environments interact with each other as a system, and the biosphere planet functions as a global ecosystem. Therefore, it is necessary for children to understand relationships in ecosystems, and we have to develop systems thinking in our students. Ecosystem approach and systems thinking should help us to solve global environmental problems. How do we implement the ecosystem approach? Students must understand that our biosphere functions as a single ecosystem and even small changes can lead to environmental disasters. Even the disappearance of one plant or animal species can lead to irreversible consequences. So in the classroom we learn the importance of each living organism for the nature. We pay special attention to endangered species, which are listed in the Red Data List. Kids are doing projects about these organisms, make videos, print brochures and newspapers. Fieldwork also plays an important role for ecosystem approach. Every summer, we go out for expeditions to study species of plants and animals listed in the Red Data List of Tatarstan. In class, students often write essays on behalf of any endangered species of plants or animals, this also helps them to understand the importance of each living organism in nature. Each spring we organise a festival of environmental projects among students. Groups of 4-5 students work on a solution of environmental problems, such as water, air or soil pollution, waste recycling, the loss of biodiversity, etc. Participants shoot a clip about their project, print brochures. Furthermore, some of the students participate in national and international scientific Olympiads with their projects. In addition to

POWER LOSSES ASSESSMENT IN TRANSFORMERS AFTER THE NORMATIVE OPERATING PERIOD

Directory of Open Access Journals (Sweden)

M. I. Fursanov

2015-01-01

Full Text Available The capacity losses values both loading and off-load are topmost parameters characterizing the distribution mains customers’ transformers operating effectiveness. Precise determination of the specified values facilitates substantiated choice of the optimizing procedures. The actuality of the given topic increases owing to the fact that the modern electric grid utilizes plenty of the oil-transformers whose time in commission considerably exceeds the statutory 25 years. Under the conditions of continued operation the power-losses measurement according to the functioning guidelines does not seem always possible.The authors present an improved power-losses assessment technique based on the currently accepted thermal model of the oil-transformer. They indicate the deficiency of the existing technique and substantiate some of the changes in practical application of the mathematical model. The article makes an emphasis on peculiarities of the temperature changes in the oil-transformer and offers a prototype device of open architecture for realizing the improved technique of the power-losses measurement. The paper describes the device design features and functionality options and depicts its sketchy schematic. The authors note the potential of additional to assessing the power-losses volume, transmitting the obtained information to the dispatcher  via  GSM-connection  for  simplification  of  the  transformer  status  monitoring; as well as the capability of integrating the device into the system of the transformer thermal protection. The practical merit and application scope of the obtained results are in development and choice of the optimizing measures to be taken in the distributive electrical grids, e. g. the transformer replacement.

An Evaluation of Intra‑ and Post‑operative Blood Loss in Total Hip ...

African Journals Online (AJOL)

2017-05-18

May 18, 2017 ... Results: The mean intra‑ and post‑operative blood losses were 1222.7 ... To evaluate blood loss after total hip replacement. 2. To evaluate the .... 12.3. 4.2. 0.1. Median. 400.0. 150.0. 20.0. 3.0. Mode. 400.0. 100.0. 0.0. 3.0. SD.

Strong and nonlinear effects of fragmentation on ecosystem service provision at multiple scales

Science.gov (United States)

Mitchell, Matthew G. E.; Bennett, Elena M.; Gonzalez, Andrew

2015-09-01

Human actions, such as converting natural land cover to agricultural or urban land, result in the loss and fragmentation of natural habitat, with important consequences for the provision of ecosystem services. Such habitat loss is especially important for services that are supplied by fragments of natural land cover and that depend on flows of organisms, matter, or people across the landscape to produce benefits, such as pollination, pest regulation, recreation and cultural services. However, our quantitative knowledge about precisely how different patterns of landscape fragmentation might affect the provision of these types of services is limited. We used a simple, spatially explicit model to evaluate the potential impact of natural land cover loss and fragmentation on the provision of hypothetical ecosystem services. Based on current literature, we assumed that fragments of natural land cover provide ecosystem services to the area surrounding them in a distance-dependent manner such that ecosystem service flow depended on proximity to fragments. We modeled seven different patterns of natural land cover loss across landscapes that varied in the overall level of landscape fragmentation. Our model predicts that natural land cover loss will have strong and unimodal effects on ecosystem service provision, with clear thresholds indicating rapid loss of service provision beyond critical levels of natural land cover loss. It also predicts the presence of a tradeoff between maximizing ecosystem service provision and conserving natural land cover, and a mismatch between ecosystem service provision at landscape versus finer spatial scales. Importantly, the pattern of landscape fragmentation mitigated or intensified these tradeoffs and mismatches. Our model suggests that managing patterns of natural land cover loss and fragmentation could help influence the provision of multiple ecosystem services and manage tradeoffs and synergies between services across different human

26 CFR 1.996-8 - Effect of carryback of capital loss or net operating loss to prior DISC taxable year.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 10 2010-04-01 2010-04-01 false Effect of carryback of capital loss or net operating loss to prior DISC taxable year. 1.996-8 Section 1.996-8 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Domestic International Sales...

Tracing and Prediction of Losses for Deregulated Operation of Power Systems

DEFF Research Database (Denmark)

Nallagownden, Perumal; Mukerjee, Ravindra Nath; Masri, Syafrudin

2011-01-01

To facilitate both generation and retailing to have an open access to the transmission grid for trading electricity, a real time procedure is proposed. The line flows for an operation are assumed to be available from PMU and WAM validated state estimation. Power tracing determines different...... at the retail end and its associated line losses, for an oncoming operating scenario....

IT Operational Risk Measurement Model Based on Internal Loss Data of Banks

Science.gov (United States)

Hao, Xiaoling

Business operation of banks relies increasingly on information technology (IT) and the most important role of IT is to guarantee the operational continuity of business process. Therefore, IT Risk management efforts need to be seen from the perspective of operational continuity. Traditional IT risk studies focused on IT asset-based risk analysis and risk-matrix based qualitative risk evaluation. In practice, IT risk management practices of banking industry are still limited to the IT department and aren't integrated into business risk management, which causes the two departments to work in isolation. This paper presents an improved methodology for dealing with IT operational risk. It adopts quantitative measurement method, based on the internal business loss data about IT events, and uses Monte Carlo simulation to predict the potential losses. We establish the correlation between the IT resources and business processes to make sure risk management of IT and business can work synergistically.

CO2 Losses from Terrestrial Organic Matter through Photodegradation

Science.gov (United States)

Rutledge, S.; Campbell, D. I.; Baldocchi, D. D.; Schipper, L. A.

2010-12-01

Net ecosystem exchange (NEE) is the sum of CO2 uptake by plants and CO2 losses from both living plants and dead organic matter. In all but a few ecosystem scale studies on terrestrial carbon cycling, losses of CO2 from dead organic matter are assumed to be the result of microbial respiration alone. Here we provide evidence for an alternative, previously largely underestimated mechanism for ecosystem-scale CO2 emissions. The process of photodegradation, the direct breakdown of organic matter by solar radiation, was found to contribute substantially to the ecosystem scale CO2 losses at both a bare peatland in New Zealand, and a summer-dead grassland in California. Comparisons of daytime eddy covariance (EC) data with data collected at the same time using an opaque chamber and the CO2 soil gradient technique, or with night-time EC data collected during similar moisture and temperature conditions were used to quantify the direct effect of exposure of organic matter to solar radiation. At a daily scale, photodegradation contributed up to 62% and 92% of summer mid-day CO2 fluxes at the de-vegetated peatland and at the grassland during the dry season, respectively. Irradiance-induced CO2 losses were estimated to be 19% of the total annual CO2 loss at the peatland, and almost 60% of the dry season CO2 loss at the grassland. Small-scale measurements using a transparent chamber confirmed that CO2 emissions from air-dried peat and grass occurred within seconds of exposure to light when microbial activity was inhibited. Our findings imply that photodegradation could be important for many ecosystems with exposed soil organic matter, litter and/or standing dead material. Potentially affected ecosystems include sparsely vegetated arid and semi-arid ecosystems (e.g. shrublands, savannahs and other grasslands), bare burnt areas, agricultural sites after harvest or cultivation (especially if crop residues are left on the surface), deciduous forests after leaf fall, or ecosystems

Monetary ecosystem services valuation in natural environment management

OpenAIRE

Álvarez, David

2017-01-01

As it happened with Stern Report, which made international community change their attitude related to climate change, TEEB (The Economics of Ecosystem Services and Biodiversity) was a turning point in valuing biodiversity and ecosystem services. This change of attitude happened, partially, thanks to include monetary ecosystem valuation of ecosystem services and how much their conservation and avoid their loss worth to the entire society. Integrate monetary valuation in green infrastructur...

Terrestrial ecosystems and biodiversity

CSIR Research Space (South Africa)

Davis-Reddy, Claire

2017-10-01

Full Text Available Ecoregions Terrestrial Biomes Protected Areas Climate Risk and Vulnerability: A Handbook for Southern Africa | 75 7.2. Non-climatic drivers of ecosystem change 7.2.1. Land-use change, habitat loss and fragmentation Land-use change and landscape... concentrations of endemic plant and animal species, but these mainly occur in areas that are most threatened by human activity. Diverse terrestrial ecosystems in the region include tropical and sub-tropical forests, deserts, savannas, grasslands, mangroves...

Quantifying effects of biodiversity on ecosystem functioning across times and places†

Science.gov (United States)

Isbell, Forest; Cowles, Jane; Dee, Laura E.; Loreau, Michel; Reich, Peter B.; Gonzalez, Andrew; Hector, Andy; Schmid, Bernhard

2018-01-01

Biodiversity loss decreases ecosystem functioning at the local scales at which species interact, but it remains unclear how biodiversity loss affects ecosystem functioning at the larger scales of space and time that are most relevant to biodiversity conservation and policy. Theory predicts that additional insurance effects of biodiversity on ecosystem functioning could emerge across time and space if species respond asynchronously to environmental variation and if species become increasingly dominant when and where they are most productive. Even if only a few dominant species maintain ecosystem functioning within a particular time and place, ecosystem functioning may be enhanced by many different species across many times and places (β-diversity). Here, we develop and apply a new approach to estimate these previously unquantified insurance effects of biodiversity on ecosystem functioning that arise due to species turnover across times and places. In a long-term (18-year) grassland plant diversity experiment, we find that total insurance effects are positive in sign and substantial in magnitude, amounting to 19% of the net biodiversity effect, mostly due to temporal insurance effects. Species loss can therefore reduce ecosystem functioning both locally and by eliminating species that would otherwise enhance ecosystem functioning across temporally fluctuating and spatially heterogeneous environments. PMID:29493062

Innovative financing mechanisms for sustainable ecosystem management

NARCIS (Netherlands)

Meijerink, G.W.; Diemont, W.H.; Groot, de R.S.; Schrijver, R.A.M.; Verhagen, A.

2008-01-01

The increasing human influence on ecosystems and the ensuing unsustainable exploitation and degradation has led in many places to depletion and loss of function of these ecosystems. These problems cannot be solved by (innovative) financing mechanisms, as the causes do not lie in a lack of financing

Biodiversity and Resilience of Ecosystem Functions.

Science.gov (United States)

Oliver, Tom H; Heard, Matthew S; Isaac, Nick J B; Roy, David B; Procter, Deborah; Eigenbrod, Felix; Freckleton, Rob; Hector, Andy; Orme, C David L; Petchey, Owen L; Proença, Vânia; Raffaelli, David; Suttle, K Blake; Mace, Georgina M; Martín-López, Berta; Woodcock, Ben A; Bullock, James M

2015-11-01

Accelerating rates of environmental change and the continued loss of global biodiversity threaten functions and services delivered by ecosystems. Much ecosystem monitoring and management is focused on the provision of ecosystem functions and services under current environmental conditions, yet this could lead to inappropriate management guidance and undervaluation of the importance of biodiversity. The maintenance of ecosystem functions and services under substantial predicted future environmental change (i.e., their 'resilience') is crucial. Here we identify a range of mechanisms underpinning the resilience of ecosystem functions across three ecological scales. Although potentially less important in the short term, biodiversity, encompassing variation from within species to across landscapes, may be crucial for the longer-term resilience of ecosystem functions and the services that they underpin. Copyright © 2015 Elsevier Ltd. All rights reserved.

Can an "Aesthetic" Intervention (Braided Hair Coil) Cause Hair Loss After an Aesthetic Operation?

Science.gov (United States)

Dionyssopoulos, Alexander; Papaconstantinou, Antony; Stoltidou, Alexandra; Spyropoulou, Georgia-Alexandra

2014-07-01

Postoperative pressure alopecia (PPA), defined as hair loss caused by prolonged pressure on the patient's scalp during surgery, is an uncommon condition after aesthetic surgery. Originally, it was described for patients who underwent lengthy cardiovascular and gynecologic operations. The authors present a rare case, in which hair loss occurred after secondary breast augmentation (replacement of breast implants). The PPA appeared in the occipitoparietal region of the patient's scalp approximately 2 weeks after surgery. The operation was completed in less than 3 hours, without any fluctuations in the patient's blood pressure or any unusual blood loss. There were no other precipitating factors such as anemia or coagulopathies. The probable cause of this unexpected result was the patient's braided hair coil, which had not been noted before the operation. The patient habitually, and on the day of her operation, combed her hair into a braided coil, which placed extra pressure on the occipitoparietal region. The hair loss was temporary, and hair regrowth was complete within 2 months. This incident may have been avoided if the braided hair coil had been noted by nursing or other medical staff preoperatively. Repositioning the head every 30 minutes and providing adequate head padding during surgery are advised to protect the patient and prevent such incidents. 5. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

Evaluation of a loss of residual heat removal event during mid-loop operation

International Nuclear Information System (INIS)

Seul, Kwang Won; Bang, Young Seok; Lee, Sukho; Kim, Hho Jung

1996-01-01

The potential for the RELAP5/MOD3.2 was assessed for the loss-of -RHR event during the mid-loop operation and the predictability of major thermal-hydraulic phenomena was also evaluated for the long term transient. The analysis results of the typical two cases(cold leg opening case and pressurizer opening case) were compared with experimental data which was conducted at ROSA-IV/LSTF in Japan. As a result, it was shown that the code was capable of simulating the thermal-hydraulic transport process with appropriate time step during the reduced inventory operation with the loss-of-RHR system

Global climate change and California's natural ecosystems

International Nuclear Information System (INIS)

Botkin, D.B.; Nisbet, R.A.; Woodhouse, C.; Ferren, W.; Bicknell, S.; Bentley, B.

1991-01-01

If projections of global climate models are correct, the natural ecosystems of California might undergo major changes during the next century. Such changes might include large economic losses in timber, fisheries, and recreation; major changes in our national and state parks and forests and in our nature preserves and conservation areas; increase in extinction of endangered species; loss of large areas of existing habitats; and development of new habitats whose location and areal extent can only be surmised. Many areas currently set aside for the conservation of specific ecosystems might no longer be suitable to them. Yet, in spite of the potential seriousness of these problems, which could dwarf all other environmental changes, California is at present in a poor situation to project what the effects of global change on its natural ecosystems might be

PLANNING THE WEDDING: DEVELOPMENT BASED UPON ECOSYSTEMS

Science.gov (United States)

Changing land uses to meet needs and expectations of the growing human population is largely responsible for habitat loss, species extinctions, deterioration of water quality and quantity, soil losses and depletion, and ecosystem goods and services. Although such development is...

Synergies, Trade-offs, and Losses of Ecosystem Services in Urban Regions: an Integrated Multiscale Framework Applied to the Leipzig-Halle Region, Germany

Directory of Open Access Journals (Sweden)

Dagmar Haase

2012-09-01

Full Text Available Because we have entered the 'millennium of the cities', urban ecological research needs to account for the provisions ecosystem services provide to urban regions. In urban areas, ecosystem service assessment studies need to account for the complex land use patterns, which change over relatively short periods of time. We discuss an analytical framework for the spatial and temporal integration of different ecosystem services in an urban region to determine synergies, trade-offs and losses, and we employ a case study in Leipzig-Halle, Germany. The following five ecosystem services, which are of special importance for urban areas, were selected: local climate regulation, recreation potential, biodiversity potential, food supply, and above-ground carbon storage. These services were analyzed from 1990 to 2006. Our results identified only slight increases in urbanization (1% or 3 km² and in mining restoration (-11 km². However, the detected land use changes led to synergies with biodiversity and climate regulation of > 50% of the total area, whereas trade-offs of approximately 60% were detected between variables such as climate regulation and recreation. Finally, we address both the opportunities and the challenges that were encountered in the integration study, specifically with respect to the application in land use planning.

Equity and the Conservation of Global Ecosystem Services

NARCIS (Netherlands)

Davidson, M.D.

This article provides a first rough sketch of how to conceptualize countries’ present and historical contributions to the loss of global ecosystem services, i.e., ecosystem services of which the delivery is global and omnidirectional, and discusses the implications of questions concerning the

Resilience and stability of a pelagic marine ecosystem

DEFF Research Database (Denmark)

Lindegren, Martin; Checkley, David M.; Ohman, Mark D.

2016-01-01

The accelerating loss of biodiversity and ecosystem services worldwide has accentuated a long-standing debate on the role of diversity in stabilizing ecological communities and has given rise to a field of research on biodiversity and ecosystem functioning (BEF). Although broad consensus has been...

Elevated CO2 and temperature increase soil C losses from a soybean-maize ecosystem.

Science.gov (United States)

Black, Christopher K; Davis, Sarah C; Hudiburg, Tara W; Bernacchi, Carl J; DeLucia, Evan H

2017-01-01

Warming temperatures and increasing CO 2 are likely to have large effects on the amount of carbon stored in soil, but predictions of these effects are poorly constrained. We elevated temperature (canopy: +2.8 °C; soil growing season: +1.8 °C; soil fallow: +2.3 °C) for 3 years within the 9th-11th years of an elevated CO 2 (+200 ppm) experiment on a maize-soybean agroecosystem, measured respiration by roots and soil microbes, and then used a process-based ecosystem model (DayCent) to simulate the decadal effects of warming and CO 2 enrichment on soil C. Both heating and elevated CO 2 increased respiration from soil microbes by ~20%, but heating reduced respiration from roots and rhizosphere by ~25%. The effects were additive, with no heat × CO 2 interactions. Particulate organic matter and total soil C declined over time in all treatments and were lower in elevated CO 2 plots than in ambient plots, but did not differ between heat treatments. We speculate that these declines indicate a priming effect, with increased C inputs under elevated CO 2 fueling a loss of old soil carbon. Model simulations of heated plots agreed with our observations and predicted loss of ~15% of soil organic C after 100 years of heating, but simulations of elevated CO 2 failed to predict the observed C losses and instead predicted a ~4% gain in soil organic C under any heating conditions. Despite model uncertainty, our empirical results suggest that combined, elevated CO 2 and temperature will lead to long-term declines in the amount of carbon stored in agricultural soils. © 2016 John Wiley & Sons Ltd.

Parallel ecological networks in ecosystems

Science.gov (United States)

Olff, Han; Alonso, David; Berg, Matty P.; Eriksson, B. Klemens; Loreau, Michel; Piersma, Theunis; Rooney, Neil

2009-01-01

In ecosystems, species interact with other species directly and through abiotic factors in multiple ways, often forming complex networks of various types of ecological interaction. Out of this suite of interactions, predator–prey interactions have received most attention. The resulting food webs, however, will always operate simultaneously with networks based on other types of ecological interaction, such as through the activities of ecosystem engineers or mutualistic interactions. Little is known about how to classify, organize and quantify these other ecological networks and their mutual interplay. The aim of this paper is to provide new and testable ideas on how to understand and model ecosystems in which many different types of ecological interaction operate simultaneously. We approach this problem by first identifying six main types of interaction that operate within ecosystems, of which food web interactions are one. Then, we propose that food webs are structured among two main axes of organization: a vertical (classic) axis representing trophic position and a new horizontal ‘ecological stoichiometry’ axis representing decreasing palatability of plant parts and detritus for herbivores and detrivores and slower turnover times. The usefulness of these new ideas is then explored with three very different ecosystems as test cases: temperate intertidal mudflats; temperate short grass prairie; and tropical savannah. PMID:19451126

How Can a Little Shrimp Do so Much Damage?: Ecosystem Service Losses Associated with Land Cover Change in Mangroves

Science.gov (United States)

Kauffman, J. B.; Bhomia, R. K.

2014-12-01

Mangroves provide a number of ecosystem services including habitats for many species of fish and shellfish, storm protection, influences on water quality, wood, aesthetics, and a source of nutrients and energy for adjacent marine ecosystems. C stocks of mangroves are among the highest of any forest type on Earth. We have measured the ecosystem carbon stocks in mangroves across the world and found them to range from 250 to >2000 Mg C/ha which is a CO2 equivalence of 917 to 7340 Mg/ha. Because the numerous values of mangroves are well known, it is ironic that rates of deforestation largely relating to land use/land cover change are among the highest of any forest type on earth exceeding that of tropical rain forests. Dominant causes of deforestation include conversion to aquaculture (shrimp), agricultural conversion, and coastal development. The carbon emissions arising from conversion of mangroves to other uses is exceptionally high. This is because vulnerability of the soil carbon stocks to losses with conversion. Emissions from conversion of mangrove to shrimp ponds range from about 800 to over 3000 Mg CO2e/ha. This places the carbon footprint of shrimp arising from such ponds as among the highest of any food product available. Of great interest is the potential value of mangroves in carbon marketing strategies and other financial incentives that are derived from the conservation of standing forests. This is because of the combination of high carbon stocks in intact mangroves, the high greenhouse gas emissions arising from their conversion, and the conservation of other valuable ecosystem services provided by intact mangroves.

Extinction order and altered community structure rapidly disrupt ecosystem functioning.

Science.gov (United States)

Larsen, Trond H; Williams, Neal M; Kremen, Claire

2005-05-01

By causing extinctions and altering community structure, anthropogenic disturbances can disrupt processes that maintain ecosystem integrity. However, the relationship between community structure and ecosystem functioning in natural systems is poorly understood. Here we show that habitat loss appeared to disrupt ecosystem functioning by affecting extinction order, species richness and abundance. We studied pollination by bees in a mosaic of agricultural and natural habitats in California and dung burial by dung beetles on recently created islands in Venezuela. We found that large-bodied bee and beetle species tended to be both most extinction-prone and most functionally efficient, contributing to rapid functional loss. Simulations confirmed that extinction order led to greater disruption of function than predicted by random species loss. Total abundance declined with richness and also appeared to contribute to loss of function. We demonstrate conceptually and empirically how the non-random response of communities to disturbance can have unexpectedly large functional consequences.

Recovery from disturbance requires resynchronization of ecosystem nutrient cycles.

Science.gov (United States)

Rastetter, E B; Yanai, R D; Thomas, R Q; Vadeboncoeur, M A; Fahey, T J; Fisk, M C; Kwiatkowski, B L; Hamburg, S P

2013-04-01

Nitrogen (N) and phosphorus (P) are tightly cycled in most terrestrial ecosystems, with plant uptake more than 10 times higher than the rate of supply from deposition and weathering. This near-total dependence on recycled nutrients and the stoichiometric constraints on resource use by plants and microbes mean that the two cycles have to be synchronized such that the ratio of N:P in plant uptake, litterfall, and net mineralization are nearly the same. Disturbance can disrupt this synchronization if there is a disproportionate loss of one nutrient relative to the other. We model the resynchronization of N and P cycles following harvest of a northern hardwood forest. In our simulations, nutrient loss in the harvest is small relative to postharvest losses. The low N:P ratio of harvest residue results in a preferential release of P and retention of N. The P release is in excess of plant requirements and P is lost from the active ecosystem cycle through secondary mineral formation and leaching early in succession. Because external P inputs are small, the resynchronization of the N and P cycles later in succession is achieved by a commensurate loss of N. Through succession, the ecosystem undergoes alternating periods of N limitation, then P limitation, and eventually co-limitation as the two cycles resynchronize. However, our simulations indicate that the overall rate and extent of recovery is limited by P unless a mechanism exists either to prevent the P loss early in succession (e.g., P sequestration not stoichiometrically constrained by N) or to increase the P supply to the ecosystem later in succession (e.g., biologically enhanced weathering). Our model provides a heuristic perspective from which to assess the resynchronization among tightly cycled nutrients and the effect of that resynchronization on recovery of ecosystems from disturbance.

Ecosystem heterogeneity determines the ecological resilience of the Amazon to climate change.

Science.gov (United States)

Levine, Naomi M; Zhang, Ke; Longo, Marcos; Baccini, Alessandro; Phillips, Oliver L; Lewis, Simon L; Alvarez-Dávila, Esteban; Segalin de Andrade, Ana Cristina; Brienen, Roel J W; Erwin, Terry L; Feldpausch, Ted R; Monteagudo Mendoza, Abel Lorenzo; Nuñez Vargas, Percy; Prieto, Adriana; Silva-Espejo, Javier Eduardo; Malhi, Yadvinder; Moorcroft, Paul R

2016-01-19

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

Seed dispersal as an ecosystem service: frugivore loss leads to decline of a socially valued plant, Capsicum frutescens.

Science.gov (United States)

Egerer, Monika H; Fricke, Evan C; Rogers, Haldre S

2018-04-01

Species interactions, both mutualistic and antagonistic, are widely recognized as providing important ecosystem services. Fruit-eating animals influence plant recruitment by increasing germination during gut passage and moving seeds away from conspecifics. However, relative to studies focused on the importance of frugivores for plant population maintenance, few studies target frugivores as ecosystem service providers, and frugivores are underappreciated as ecosystem service providers relative to other mutualists such as pollinators. Here, we use an accidental experiment to elucidate the role of seed dispersal by frugivores for maintaining a culturally and economically important plant, the donne' sali chili (Capsicum frutescens) in the Mariana Islands. One of the islands (Guam) has lost nearly all of its native forest birds due to an invasive snake (Boiga irregularis), whereas nearby islands have relatively intact bird populations. We hypothesized that frugivore loss would influence chili recruitment and abundance, which could have economic and cultural impacts. By using video cameras, we confirmed that birds were the primary seed dispersers. We used captive bird feeding trials to obtain gut-passed seeds to use in a seedling emergence experiment. The experiment showed that gut-passed seeds emerged sooner and at a higher proportion than seeds from whole fruits. Consistent with our findings that birds benefit chilies, we observed lower chili abundance on Guam than on islands with birds. In a survey questionnaire of island residents, the majority of residents reported an association between the wild chili and local cultural values and traditions. In addition, we identified a thriving market for chili products, suggesting benefits of wild chilies to people in the Marianas both as consumers and producers. Our study therefore documents seed dispersal as both a cultural and a supporting ecosystem service. We provide a comprehensive case study on how seed-dispersed plants

Mapping cultural ecosystem services:

DEFF Research Database (Denmark)

Paracchini, Maria Luisa; Zulian, Grazia; Kopperoinen, Leena

2014-01-01

Research on ecosystem services mapping and valuing has increased significantly in recent years. However, compared to provisioning and regulating services, cultural ecosystem services have not yet been fully integrated into operational frameworks. One reason for this is that transdisciplinarity...... surveys are a main source of information. Among cultural ecosystem services, assessment of outdoor recreation can be based on a large pool of literature developed mostly in social and medical science, and landscape and ecology studies. This paper presents a methodology to include recreation...... in the conceptual framework for EU wide ecosystem assessments (Maes et al., 2013), which couples existing approaches for recreation management at country level with behavioural data derived from surveys, and population distribution data. The proposed framework is based on three components: the ecosystem function...

Biotic elements of NPP techno-ecosystem

International Nuclear Information System (INIS)

Protasov, A.A.; Silaeva, A.A.

2013-01-01

Specific features of biotic elements in the NPP techno-ecosystems were considered and compared with natural ecosystems. Relationships between biotic communities and environmental factors that are specific to the techno-ecosystems were discussed, and the problems of limitation of biological hindrances in operation of equipment, principles of hydrobiological and environmental monitoring were considered.

The Economics of Ecosystems and Biodiversity: Ecological and Economic Foundations.

OpenAIRE

John M. Gowdy; Richard Howarth; Clem Tisdell

2010-01-01

This chapter presents the economic logic behind the concept of discounting the future and discusses how it applies to biodiversity conservation. How should economists account for the effects of biodiversity and ecosystem losses in the immediate and distant future? We discuss how to integrate traditional cost-benefit analysis with other approaches to understand and measure, where possible, environmental values. We conclude that losses of biodiversity and ecosystems have properties that make it...

Conceptualizing the role of sediment in sustaining ecosystem services: Sediment-ecosystem regional assessment (SEcoRA).

Science.gov (United States)

Apitz, Sabine E

2012-01-15

There is a growing trend to include a consideration of ecosystem services, the benefits that people obtain from ecosystems, within decision frameworks. Not more than a decade ago, sediment management efforts were largely site-specific and held little attention except in terms of managing contaminant inputs and addressing sediments as a nuisance at commercial ports and harbors. Sediments figure extensively in the Millennium Ecosystem Assessment; however, contaminated sediment is not the dominant concern. Rather, the focus is on land and water use and management on the landscape scale, which can profoundly affect soil and sediment quality, quantity and fate. Habitat change and loss, due to changes in sediment inputs, whether reductions (resulting in the loss of beaches, storm protection, nutrient inputs, etc.) or increases (resulting in lake, reservoir and wetland infilling, coral reef smothering, etc.); eutrophication and reductions in nutrient inputs, and disturbance due to development and fishing practices are considered major drivers, with significant consequences for biodiversity and the provision and resilience of ecosystem functions and services. As a mobile connecting medium between various parts of the ecosystem via the hydrocycle, sediments both contaminated and uncontaminated, play both positive and negative roles in the viability and sustainability of social, economic, and ecological objectives. How these roles are interpreted depends upon whether sediment status (defined in terms of sediment quality, quantity, location and transport) is appropriate to the needs of a given endpoint; understanding and managing the dynamic interactions of sediment status on a diverse range of endpoints at the landscape or watershed scale should be the focus of sediment management. This paper seeks to provide a language and conceptual framework upon which sediment-ecosystem regional assessments (SEcoRAs) can be developed in support of that goal. Copyright © 2011 Elsevier B

Death of an ecosystem: perspectives on western white pine ecosystems of North America at the end of the twentieth century

Science.gov (United States)

Alan E. Harvey; James W. Byler; Geral I. McDonald; Leon F. Neuenschwander; Jonalea R. Tonn

2008-01-01

The effective loss of western white pine (Pinus monticola Dougl.) in the white pine ecosystem has far-reaching effects on the sustainability of local forests and both regional and global forestry issues. Continuing trends in management of this forest type has the potential to put western white pine, as well as the ecosystem it once dominated, at very...

Operator modeling of a loss-of-pumping accident using MicroSAINT

International Nuclear Information System (INIS)

Olsen, L.M.

1992-01-01

The Savannah River Laboratory (SRL) human factors group has been developing methods for analyzing nuclear reactor operator actions during hypothetical design-basis accident scenarios. The SRL reactors operate at a lower temperature and pressure than power reactors resulting in accident sequences that differ from those of power reactors. Current methodology development is focused on modeling control room operator response times dictated by system event times specified in the Savannah River Site Reactor Safety Analysis Report (SAR). The modeling methods must be flexible enough to incorporate changes to hardware, procedures, or postulated system event times and permit timely evaluation. The initial model developed was for the loss-of-pumping accident (LOPA) because a significant number of operator actions are required to respond to this postulated event. Human factors engineers had been researching and testing a network modeling simulation language called MicroSAINT to simulate operators' personal and interpersonal actions relative to operating system events. The LOPA operator modeling project demonstrated the versatility and flexibility of MicroSAINT for modeling control room crew interactions

Context dependency and saturating effects of loss of rare soil microbes on plant productivity

NARCIS (Netherlands)

Hol, Gera; De Boer, Wietse; de Hollander, Mattias; Kuramae, Eiko Eurya; Meisner, Annelein; van der Putten, Wim

2015-01-01

Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received

Unusually Warm Spring Temperatures Magnify Annual CH4 Losses From Arctic Ecosystems

Science.gov (United States)

Goodrich, J. P.; Oechel, W. C.; Gioli, B.; Murphy, P.; Zona, D.

2015-12-01

The relatively fast pace of Northern high latitude warming puts the very large permafrost soil C pool at a higher risk of being lost to the atmosphere as CH4. Estimates for the Arctic tundra's contribution to the global wetland CH4 emissions range from 15-27 TgCH4 y-1 (8-14% of total). However, these estimates are largely based on data from the growing season, or from boreal systems underlain by discontinuous permafrost with different physical, hydrological, and biogeochemical dynamics than continuous permafrost zones. Recent data from a transect of eddy covariance flux towers across the North Slope of Alaska revealed the importance of cold season emissions to the annual CH4 budget, which may not correlate with summer flux patterns. However, understanding of the controls and inter-annual variability in fluxes at these different sites is lacking. Here, we present data from ~3 years at 5 tundra ecosystems along this Arctic transect to show the influence of earlier and deeper spring active layer thaw on timing and magnitude of CH4 fluxes. This year's warm spring led to significantly greater thaw depths and lower water tables than the previous year. Substantial CH4 emissions in 2015 were recorded at the wettest sites >20 days earlier than in the more meteorologically normal previous year. Since the soil remained saturated despite a lowered water table, total spring CH4 emissions more than doubled at these wet sites. At the drier sites, soil moisture declined with water table during the warmer spring, resulting in similar emissions to the previous year. However, deeper thaw depths prolonged fall and early winter emissions during the 'zero-curtain' soil temperature freezing phase, particularly at the drier site. In general, warmer spring temperatures in the Arctic may result in large increases in early season CH4 losses at wet sites and prolonged steady losses at the upland sites, enhancing the feedback between changing climate and tundra CH4 emissions at all sites.

Operating Experiences of a Loss of Voltage Monitoring Program

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun-Chan [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

2015-10-15

Loss of voltage (LOV) events continue to occur due to inadequate work management and random human errors. On February 26, 2015, regulators analyzed the root causes of LOV events and presented the results for the nuclear industry. Currently, KHNP uses a risk monitoring program, which is named 'LOV Monitor', for LOV prevention during pilot plant outages. This review introduces the operation experiences of LOV Monitor based on the evaluation results of a real event. The operation experiences of LOV Monitor in the pilot plants confirmed that this program could detect and reduce LOV possibilities from scheduling errors such as the simultaneous maintenance of energized trains and de-energized trains considering the physical conditions of the power circuit breakers. However, a maintenance culture that heeds the risk monitoring result must be strengthened in order to obtain substantial effects through applying LOV Monitor to the outage.

An Approach for Simulating Soil Loss from an Agro-Ecosystem Using Multi-Agent Simulation: A Case Study for Semi-Arid Ghana

Directory of Open Access Journals (Sweden)

Biola K. Badmos

2015-07-01

Full Text Available Soil loss is not limited to change from forest or woodland to other land uses/covers. It may occur when there is agricultural land-use/cover modification or conversion. Soil loss may influence loss of carbon from the soil, hence implication on greenhouse gas emission. Changing land use could be considered actually or potentially successful in adapting to climate change, or may be considered maladaptation if it creates environmental degradation. In semi-arid northern Ghana, changing agricultural practices have been identified amongst other climate variability and climate change adaptation measures. Similarly, some of the policies aimed at improving farm household resilience toward climate change impact might necessitate land use change. The heterogeneity of farm household (agents cannot be ignored when addressing land use/cover change issues, especially when livelihood is dependent on land. This paper therefore presents an approach for simulating soil loss from an agro-ecosystem using multi-agent simulation (MAS. We adapted a universal soil loss equation as a soil loss sub-model in the Vea-LUDAS model (a MAS model. Furthermore, for a 20-year simulation period, we presented the impact of agricultural land-use adaptation strategy (maize cultivation credit i.e., maize credit scenario on soil loss and compared it with the baseline scenario i.e., business-as-usual. Adoption of maize as influenced by maize cultivation credit significantly influenced agricultural land-use change in the study area. Although there was no significant difference in the soil loss under the tested scenarios, the incorporation of human decision-making in a temporal manner allowed us to view patterns that cannot be seen in single step modeling. The study shows that opening up cropland on soil with a high erosion risk has implications for soil loss. Hence, effective measures should be put in place to prevent the opening up of lands that have high erosion risk.

A Size-based Ecosystem Model

DEFF Research Database (Denmark)

Ravn-Jonsen, Lars

 Ecosystem Management requires models that can link the ecosystem level to the operation level. This link can be created by an ecosystem production model. Because the function of the individual fish in the marine ecosystem, seen in trophic context, is closely related to its size, the model groups...... fish according to size. The model summarises individual predation events into ecosystem level properties, and thereby uses the law of conversation of mass as a framework. This paper provides the background, the conceptual model, basic assumptions, integration of fishing activities, mathematical...... the predator--prey interaction, (ii) mass balance in the predator--prey allocation, and (iii) mortality and somatic growth as a consequence of the predator--prey allocation. By incorporating additional assumptions, the model can be extended to other dimensions of the ecosystem, for example, space or species...

The role of recurrent disturbances for ecosystem multifunctionality.

Science.gov (United States)

Villnäs, Anna; Norkko, Joanna; Hietanen, Susanna; Josefson, Alf B; Lukkari, Kaarina; Norkko, Alf

2013-10-01

Ecosystem functioning is threatened by an increasing number of anthropogenic stressors, creating a legacy of disturbance that undermines ecosystem resilience. However, few empirical studies have assessed to what extent an ecosystem can tolerate repeated disturbances and sustain its multiple functions. By inducing increasingly recurring hypoxic disturbances to a sedimentary ecosystem, we show that the majority of individual ecosystem functions experience gradual degradation patterns in response to repetitive pulse disturbances. The degradation in overall ecosystem functioning was, however, evident at an earlier stage than for single ecosystem functions and was induced after a short pulse of hypoxia (i.e., three days), which likely reduced ecosystem resistance to further hypoxic perturbations. The increasing number of repeated pulse disturbances gradually moved the system closer to a press response. In addition to the disturbance regime, the changes in benthic trait composition as well as habitat heterogeneity were important for explaining the variability in overall ecosystem functioning. Our results suggest that disturbance-induced responses across multiple ecosystem functions can serve as a warning signal for losses of the adaptive capacity of an ecosystem, and might at an early stage provide information to managers and policy makers when remediation efforts should be initiated.

Operative time, blood loss, hemoglobin drop, blood transfusion, and hospital stay in orthognathic surgery.

Science.gov (United States)

Salma, Ra'ed Ghaleb; Al-Shammari, Fahad Mohammed; Al-Garni, Bishi Abdullah; Al-Qarzaee, Mohammed Abdullah

2017-06-01

This study was conducted to evaluate the operative time, blood loss, hemoglobin drop, blood transfusion, and length of hospital stay in orthognathic surgery. A 10-year retrospective analysis was performed on patients who underwent bilateral sagittal split osteotomy (with or without genioplasty), Le Fort I osteotomy (with or without genioplasty), or any combination of these procedures. A total of 271 patients were included. The age range was 17 to 49 years, with a mean age of 24.13 ± 4.51 years. Approximately 62% of patients underwent double-jaw surgery. The most common procedure was bilateral sagittal split with Le Fort I (37%). The average operative time was 3.96 ± 1.25 h. The mean estimated blood loss was 345.2 ± 149.74 mL. Approximately 9% of patients received intraoperative blood transfusion. The mean hemoglobin drop in the non-transfusion cases was 2.38 ± 0.89 g/dL. The mean postoperative hospital stay was 1.85 ± 0.83 days. Only one patient was admitted to the ICU for one night. In orthognathic surgery, blood loss is relatively minor, blood transfusion is frequent, and ICU admission is unlikely. Operative time, blood loss, blood transfusion, and the complexity of the surgical procedure can significantly increase the length of hospital stay. Males may bleed more than females in orthognathic surgery. Hemoglobin drop can be overestimated due to hemodilution in orthognathic surgery, which may influence the decision to use blood transfusion.

Regime shifts and resilience in China's coastal ecosystems.

Science.gov (United States)

Zhang, Ke

2016-02-01

Regime shift often results in large, abrupt, and persistent changes in the provision of ecosystem services and can therefore have significant impacts on human wellbeing. Understanding regime shifts has profound implications for ecosystem recovery and management. China's coastal ecosystems have experienced substantial deterioration within the past decades, at a scale and speed the world has never seen before. Yet, information about this coastal ecosystem change from a dynamics perspective is quite limited. In this review, I synthesize existing information on coastal ecosystem regime shifts in China and discuss their interactions and cascading effects. The accumulation of regime shifts in China's coastal ecosystems suggests that the desired system resilience has been profoundly eroded, increasing the potential of abrupt shifts to undesirable states at a larger scale, especially given multiple escalating pressures. Policy and management strategies need to incorporate resilience approaches in order to cope with future challenges and avoid major losses in China's coastal ecosystem services.

Soil biodiversity and soil community composition determine ecosystem multifunctionality

NARCIS (Netherlands)

Wagg, C.; Bender, S.F.; Widmer, D.; van der Heijden, Marcellus|info:eu-repo/dai/nl/240923901

2014-01-01

Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth’s biodiversity is literally

Faster N Release, but Not C Loss, From Leaf Litter of Invasives Compared to Native Species in Mediterranean Ecosystems

Directory of Open Access Journals (Sweden)

Guido Incerti

2018-04-01

Full Text Available Plant invasions can have relevant impacts on biogeochemical cycles, whose extent, in Mediterranean ecosystems, have not yet been systematically assessed comparing litter carbon (C and nitrogen (N dynamics between invasive plants and native communities. We carried out a 1-year litterbag experiment in 4 different plant communities (grassland, sand dune, riparian and mixed forests on 8 invasives and 24 autochthonous plant species, used as control. Plant litter was characterized for mass loss, N release, proximate lignin and litter chemistry by 13C CPMAS NMR. Native and invasive species showed significant differences in litter chemical traits, with invaders generally showing higher N concentration and lower lignin/N ratio. Mass loss data revealed no consistent differences between native and invasive species, although some woody and vine invaders showed exceptionally high decomposition rate. In contrast, N release rate from litter was faster for invasive plants compared to native species. N concentration, lignin content and relative abundance of methoxyl and N-alkyl C region from 13C CPMAS NMR spectra were the parameters that better explained mass loss and N mineralization rates. Our findings demonstrate that during litter decomposition invasive species litter has no different decomposition rates but greater N release rate compared to natives. Accordingly, invasives are expected to affect N cycle in Mediterranean plant communities, possibly promoting a shift of plant assemblages.

Comparing ecosystem and soil respiration: Review and key challenges of tower-based and soil mesurements

Science.gov (United States)

The net ecosystem exchange (NEE) is the difference between ecosystem CO2 assimilation and CO2 losses to the atmosphere. Ecosystem respiration (Reco), the efflux of CO2 from the ecosystem to the atmosphere, includes the soil-to-atmosphere carbon flux (i.e., soil respiration; Rsoil) and aboveground pl...

NRC Information No. 87-24: Operational experience involving losses of electrical inverters

International Nuclear Information System (INIS)

Rossi, C.E.

1992-01-01

The NRC case study report identified three potential failure mechanisms for inverters. One of these involves relatively high ambient temperature and/or humidity within inverter enclosures. This condition appears to result in accelerated aging of components that form a part of the inverter circuitry causing a significant reduction in component life expectancy and inverter loss. Another mechanism for inverter failure involves the electrical interconnecting and physical arrangements for the inverter circuitry components. In some installations, these arrangements are such that when certain components fail, other components also may fail or degrade. The third failure mechanism involves voltage spikes and perturbations. Many of the electrical loads in a plant have inductive characteristics. During plant operations that involve energizing and deenergizing these loads, voltage spikes and perturbations are generated. The solid-state devices in the inverter circuitry are sensitive to these voltage spikes, and this has resulted in component failure, blown fuses, and inverter losses. Additionally, secondary voltage perturbations caused by lighting strikes or switching surges can have an adverse effect on inverter operation

Loss of life of induction motors under various operating anomalies

International Nuclear Information System (INIS)

Chugh, Tarun; Varde, P.V.

2016-01-01

Reliability studies conducted to study the various failure modes of all induction motors shows that one of failure modes i.e. winding failure is quite prevalent and accounts for high percentage of failures of motors. Thus, there is a pivotal need to understand the theory of winding failure and know how it can be prognosticated based on the input parameters, current operating environment and maintenance history of a motor. This paper defines loss of motor life as the loss of stator winding insulation life due to thermal and environmental stresses. From the thermal point of view, the stator winding insulation is the weakest part of a squirrel cage induction motor, and equations are developed to estimate the insulation Iife and hence the motor life. In this regard, an integrated model consisting of an electrical model, thermal model and insulation ageing model is developed to evaluate the effect of various anomalies/stressors e.g. overvoltage and voltage unbalance on the life of a motor. This model is used to quantify the loss of life of a 2.3 kW, 415 V induction motor. The electrical model is developed by conducting Open Circuit and Blocked Rotor Test on the motor and thereby deriving its equivalent circuit. Using the model, the stator winding losses are calculated and given as an input to the thermal model to find the temperature rise in the stator winding. The steady state temperature of the stator winding is given as an input to the insulation aging model which predicts the loss of life. This work presents a simple technique for calculating thermal parameters based on motor testing rather than from motor design data. The insulation ageing model is developed based on Eyring Equation considering temperature and humidity as stressors. (author)

Species richness accelerates marine ecosystem restoration in the Coral Triangle.

Science.gov (United States)

Williams, Susan L; Ambo-Rappe, Rohani; Sur, Christine; Abbott, Jessica M; Limbong, Steven R

2017-11-07

Ecosystem restoration aims to restore biodiversity and valuable functions that have been degraded or lost. The Coral Triangle is a hotspot for marine biodiversity held in its coral reefs, seagrass meadows, and mangrove forests, all of which are in global decline. These coastal ecosystems support valuable fisheries and endangered species, protect shorelines, and are significant carbon stores, functions that have been degraded by coastal development, destructive fishing practices, and climate change. Ecosystem restoration is required to mitigate these damages and losses, but its practice is in its infancy in the region. Here we demonstrate that species diversity can set the trajectory of restoration. In a seagrass restoration experiment in the heart of the Coral Triangle (Sulawesi, Indonesia), plant survival and coverage increased with the number of species transplanted. Our results highlight the positive role biodiversity can play in ecosystem restoration and call for revision of the common restoration practice of establishing a single target species, particularly in regions having high biodiversity. Coastal ecosystems affect human well-being in many important ways, and restoration will become ever more important as conservation efforts cannot keep up with their loss. Published under the PNAS license.

Biomanipulation - a tool in marine ecosystem management and restoration?

DEFF Research Database (Denmark)

Lindegren, Martin; Möllmann, Christian; Hansson, Lars-Anders

2010-01-01

Widespread losses of production and conservation values make large-scale ecosystem restoration increasingly urgent. Ecological restoration by means of biomanipulation, i.e., by fishing out planktivores as to reduce the predation pressure on herbivorous zooplankton, has proven an effective tool...... in restoring degraded lakes and coastal ecosystems. Whether biomanipulation may prove a useful restoration method in open and structurally complex marine ecosystems is however still unknown. To promote a recovery of the collapsed stock of Eastern Baltic cod (Gadus morhua), large-scale biomanipulation of sprat...

Realistic diversity loss and variation in soil depth independently affect community-level plant nitrogen use.

Science.gov (United States)

Selmants, Paul C; Zavaleta, Erika S; Wolf, Amelia A

2014-01-01

Numerous experiments have demonstrated that diverse plant communities use nitrogen (N) more completely and efficiently, with implications for how species conservation efforts might influence N cycling and retention in terrestrial ecosystems. However, most such experiments have randomly manipulated species richness and minimized environmental heterogeneity, two design aspects that may reduce applicability to real ecosystems. Here we present results from an experiment directly comparing how realistic and randomized plant species losses affect plant N use across a gradient of soil depth in a native-dominated serpentine grassland in California. We found that the strength of the species richness effect on plant N use did not increase with soil depth in either the realistic or randomized species loss scenarios, indicating that the increased vertical heterogeneity conferred by deeper soils did not lead to greater complementarity among species in this ecosystem. Realistic species losses significantly reduced plant N uptake and altered N-use efficiency, while randomized species losses had no effect on plant N use. Increasing soil depth positively affected plant N uptake in both loss order scenarios but had a weaker effect on plant N use than did realistic species losses. Our results illustrate that realistic species losses can have functional consequences that differ distinctly from randomized losses, and that species diversity effects can be independent of and outweigh those of environmental heterogeneity on ecosystem functioning. Our findings also support the value of conservation efforts aimed at maintaining biodiversity to help buffer ecosystems against increasing anthropogenic N loading.

RHIC Beam Loss Monitor System Initial Operation

International Nuclear Information System (INIS)

Witkover, R. L.; Michnoff, R. J.; Geller, J. M.

1999-01-01

The RHIC Beam Loss Monitor (BLM) System is designed to prevent beam loss quenching of the superconducting magnets, and acquire loss data. Four hundred ion chambers are located around the rings to detect losses. The required 8-decade range in signal current is compressed using an RC pre-integrator ahead of a low current amplifier. A beam abort may be triggered if fast or slow losses exceed programmable threshold levels. A micro-controller based VME module sets references and gains and reads trip status for up to 64 channels. Results obtained with the detectors in the RHIC Sextant Test and the prototype electronics in the AGS-to-RHIC (AtR) transfer line are presented along with the present status of the system

Modelling and prediction of crop losses from NOAA polar-orbiting operational satellites

Directory of Open Access Journals (Sweden)

Felix Kogan

2016-05-01

Full Text Available Weather-related crop losses have always been a concern for farmers, governments, traders, and policy-makers for the purpose of balanced food supply/demands, trade, and distribution of aid to the nations in need. Among weather disasters, drought plays a major role in large-scale crop losses. This paper discusses utility of operational satellite-based vegetation health (VH indices for modelling cereal yield and for early warning of drought-related crop losses. The indices were tested in Saratov oblast (SO, one of the principal grain growing regions of Russia. Correlation and regression analysis were applied to model cereal yield from VH indices during 1982–2001. A strong correlation between mean SO's cereal yield and VH indices were found during the critical period of cereals, which starts two–three weeks before and ends two–three weeks after the heading stage. Several models were constructed where VH indices served as independent variables (predictors. The models were validated independently based on SO cereal yield during 1982–2012. Drought-related cereal yield losses can be predicted three months in advance of harvest and six–eight months in advance of official grain production statistic is released. The error of production losses prediction is 7%–10%. The error of prediction drops to 3%–5% in the years of intensive droughts.

Environmental impact assessment and monetary ecosystem service valuation of an ecosystem under different future environmental change and management scenarios; a case study of a Scots pine forest.

Science.gov (United States)

Schaubroeck, Thomas; Deckmyn, Gaby; Giot, Olivier; Campioli, Matteo; Vanpoucke, Charlotte; Verheyen, Kris; Rugani, Benedetto; Achten, Wouter; Verbeeck, Hans; Dewulf, Jo; Muys, Bart

2016-05-15

For a sustainable future, we must sustainably manage not only the human/industrial system but also ecosystems. To achieve the latter goal, we need to predict the responses of ecosystems and their provided services to management practices under changing environmental conditions via ecosystem models and use tools to compare the estimated provided services between the different scenarios. However, scientific articles have covered a limited amount of estimated ecosystem services and have used tools to aggregate services that contain a significant amount of subjective aspects and that represent the final result in a non-tangible unit such as 'points'. To resolve these matters, this study quantifies the environmental impact (on human health, natural systems and natural resources) in physical units and uses an ecosystem service valuation based on monetary values (including ecosystem disservices with associated negative monetary values). More specifically, the paper also focuses on the assessment of ecosystem services related to pollutant removal/generation flows, accounting for the inflow of eutrophying nitrogen (N) when assessing the effect of N leached to groundwater. Regarding water use/provisioning, evapotranspiration is alternatively considered a disservice because it implies a loss of (potential) groundwater. These approaches and improvements, relevant to all ecosystems, are demonstrated using a Scots pine stand from 2010 to 2089 for a combination of three environmental change and three management scenarios. The environmental change scenarios considered interannual climate variability trends and included alterations in temperature, precipitation, nitrogen deposition, wind speed, Particulate matter (PM) concentration and CO2 concentration. The addressed flows/ecosystem services, including disservices, are as follows: particulate matter removal, freshwater loss, CO2 sequestration, wood production, NOx emissions, NH3 uptake and nitrogen pollution/removal. The monetary

Rare species support vulnerable functions in high-diversity ecosystems.

Science.gov (United States)

Mouillot, David; Bellwood, David R; Baraloto, Christopher; Chave, Jerome; Galzin, Rene; Harmelin-Vivien, Mireille; Kulbicki, Michel; Lavergne, Sebastien; Lavorel, Sandra; Mouquet, Nicolas; Paine, C E Timothy; Renaud, Julien; Thuiller, Wilfried

2013-01-01

Around the world, the human-induced collapses of populations and species have triggered a sixth mass extinction crisis, with rare species often being the first to disappear. Although the role of species diversity in the maintenance of ecosystem processes has been widely investigated, the role of rare species remains controversial. A critical issue is whether common species insure against the loss of functions supported by rare species. This issue is even more critical in species-rich ecosystems where high functional redundancy among species is likely and where it is thus often assumed that ecosystem functioning is buffered against species loss. Here, using extensive datasets of species occurrences and functional traits from three highly diverse ecosystems (846 coral reef fishes, 2,979 alpine plants, and 662 tropical trees), we demonstrate that the most distinct combinations of traits are supported predominantly by rare species both in terms of local abundance and regional occupancy. Moreover, species that have low functional redundancy and are likely to support the most vulnerable functions, with no other species carrying similar combinations of traits, are rarer than expected by chance in all three ecosystems. For instance, 63% and 98% of fish species that are likely to support highly vulnerable functions in coral reef ecosystems are locally and regionally rare, respectively. For alpine plants, 32% and 89% of such species are locally and regionally rare, respectively. Remarkably, 47% of fish species and 55% of tropical tree species that are likely to support highly vulnerable functions have only one individual per sample on average. Our results emphasize the importance of rare species conservation, even in highly diverse ecosystems, which are thought to exhibit high functional redundancy. Rare species offer more than aesthetic, cultural, or taxonomic diversity value; they disproportionately increase the potential breadth of functions provided by ecosystems across

Ecosystem services provided by bats.

Science.gov (United States)

Kunz, Thomas H; Braun de Torrez, Elizabeth; Bauer, Dana; Lobova, Tatyana; Fleming, Theodore H

2011-03-01

Ecosystem services are the benefits obtained from the environment that increase human well-being. Economic valuation is conducted by measuring the human welfare gains or losses that result from changes in the provision of ecosystem services. Bats have long been postulated to play important roles in arthropod suppression, seed dispersal, and pollination; however, only recently have these ecosystem services begun to be thoroughly evaluated. Here, we review the available literature on the ecological and economic impact of ecosystem services provided by bats. We describe dietary preferences, foraging behaviors, adaptations, and phylogenetic histories of insectivorous, frugivorous, and nectarivorous bats worldwide in the context of their respective ecosystem services. For each trophic ensemble, we discuss the consequences of these ecological interactions on both natural and agricultural systems. Throughout this review, we highlight the research needed to fully determine the ecosystem services in question. Finally, we provide a comprehensive overview of economic valuation of ecosystem services. Unfortunately, few studies estimating the economic value of ecosystem services provided by bats have been conducted to date; however, we outline a framework that could be used in future studies to more fully address this question. Consumptive goods provided by bats, such as food and guano, are often exchanged in markets where the market price indicates an economic value. Nonmarket valuation methods can be used to estimate the economic value of nonconsumptive services, including inputs to agricultural production and recreational activities. Information on the ecological and economic value of ecosystem services provided by bats can be used to inform decisions regarding where and when to protect or restore bat populations and associated habitats, as well as to improve public perception of bats. © 2011 New York Academy of Sciences.

Loss on Ignition Furnace Acceptance and Operability Test Procedure

Energy Technology Data Exchange (ETDEWEB)

JOHNSON, D.C.

2000-06-01

The purpose of this Acceptance Test Procedure and Operability Test Procedure (ATP/OTP)is to verify the operability of newly installed LOI equipment, including a model 1608FL CM{trademark} Furnace, a dessicator, and balance. The operability of the furnace will be verified. The arrangement of the equipment placed in Glovebox 157-3/4 to perform Loss on Ignition (LOI) testing on samples supplied from the Thermal Stabilization line will be verified. In addition to verifying proper operation of the furnace, this ATP/OTP will also verify the air flow through the filters, verify a damper setting to establish and maintain the required differential pressure between the glovebox and the room pressure, and test the integrity of the newly installed HEPA filter. In order to provide objective evidence of proper performance of the furnace, the furnace must heat 15 crucibles, mounted on a crucible rack, to 1000 C, according to a program entered into the furnace controller located outside the glovebox. The glovebox differential pressure will be set to provide the 0.5 to 2.0 inches of water (gauge) negative pressure inside the glovebox with an airflow of 100 to 125 cubic feet per minute (cfm) through the inlet filter. The glovebox inlet Glfilter will he flow tested to ensure the integrity of the filter connections and the efficiency of the filter medium. The newly installed windows and glovebox extension, as well as all disturbed joints, will be sonically tested via ultra probe to verify no leaks are present. The procedure for DOS testing of the filter is found in Appendix A.

Mapping Ecosystem Services for Land Use Planning, the Case of Central Kalimantan

Science.gov (United States)

Sumarga, Elham; Hein, Lars

2014-07-01

Indonesia is subject to rapid land use change. One of the main causes for the conversion of land is the rapid expansion of the oil palm sector. Land use change involves a progressive loss of forest cover, with major impacts on biodiversity and global CO2 emissions. Ecosystem services have been proposed as a concept that would facilitate the identification of sustainable land management options, however, the scale of land conversion and its spatial diversity pose particular challenges in Indonesia. The objective of this paper is to analyze how ecosystem services can be mapped at the provincial scale, focusing on Central Kalimantan, and to examine how ecosystem services maps can be used for a land use planning. Central Kalimantan is subject to rapid deforestation including the loss of peatland forests and the provincial still lacks a comprehensive land use plan. We examine how seven key ecosystem services can be mapped and modeled at the provincial scale, using a variety of models, and how large scale ecosystem services maps can support the identification of options for sustainable expansion of palm oil production.

St. Louis River fish migrations: Gains and losses of ecosystem services

Science.gov (United States)

The Twin Ports fishery has undergone change from a migratory fish-based fishery to a Lake Superior-based fishery, and is now returning to a diverse fishery that includes fish of both life histories. These changes reflect past disturbances to the Great Lakes ecosystem as well as r...

Consequences in the pumps operation during a large loss of coolant accident

International Nuclear Information System (INIS)

Santos, G.A. dos; Sabundjian, G.

1991-08-01

The event of living on or turning off the operation of the Reactor Cooling Pumps - RCPs, in the case of a Loss of Coolant Accident - LOCA, has been a reason of a lot of studies after the Three Mile Island 2 accident. Thus, it was investigated a large break LOCA in the cold leg of Angra 1, with the RELAP4/MOD5 Code during the blowdown. The attained results indicated that the best performance of the core was in the case where the RCPs had been turned off in the beginning of the transient, when compared with different operation conditions of the RCPs. (author)

Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

Directory of Open Access Journals (Sweden)

Lu Wen

Full Text Available The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC, and soil total nitrogen (TN were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

Science.gov (United States)

Wen, Lu; Dong, Shikui; Li, Yuanyuan; Li, Xiaoyan; Shi, Jianjun; Wang, Yanlong; Liu, Demei; Ma, Yushou

2013-01-01

The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC), and soil total nitrogen (TN) were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe) were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

An estimation of core damage frequency of a pressurized water reactor during midloop operation due to loss of residual heat removal

International Nuclear Information System (INIS)

Chao, C.C.; Chen, C.T.; Lee, M.

1995-01-01

The core damage frequency caused by loss of residual heat removal (RHR) events was assessed during midloop operation of a Westinghouse-designed three-loop pressurized water reactor. The assessment considers two types of outages (refueling and drained maintenance) and uses failure data collected specifically for shutdown condition. Event trees were developed for five categories of loss of RHR events. Human actions to mitigate the loss of RHR events were identified and human error probabilities were quantified using the human cognitive reliability (HCR) and the technique for human error rate prediction (THERP) models. The results showed that the core damage frequency caused by loss of RHR events during midloop operation was 3.4 x 10 -5 per year. The results also showed that the core damage frequency can be reduced significantly by removing a pressurizer safety valve before entering midloop operation. The establishment of reflux cooling, i.e., decay heat removal through the steam generator secondary side, also plays an important role in mitigating the loss of RHR events during midloop operation

Development of Abnormal Operating Strategies for Loss of Ultimate Heat Sink (LOUHS) at Shutdown Mode in Westinghouse Type Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Yoon, Duk-Joo; Lee, Seung-Chan; Sung, Je-Joong; Ha, Sang Jun [KHNP CRI, Daejeon (Korea, Republic of); Hwang, Su-Hyun [FNC Tech. Co., Yongin (Korea, Republic of)

2016-10-15

Loss of all AC power is classified as one of multiple failure accident by regulatory guide of Korean accident management program. Therefore we need develop strategies for the abnormal operating procedure both of power operating and shutdown mode. This paper developed abnormal operating guideline for loss of all AC power by analysis of accident scenario in pressurized water reactor. This paper analyzed the extended SBO in shutdown operating mode and developed the operating strategy of the abnormal operation procedure. Operator action for the emergency are not required to take in 500 minutes and 60 minutes in intact and opened RCS state respectively.

Superorganism resilience: Eusociality and susceptibility of ecosystem service providing insects to stressors

Science.gov (United States)

Insects provide crucial ecosystem services for human food security and maintenance of biodiversity. Therefore, major declines in wild species combined with losses of managed bees have raised concern over the sustainability of their ecosystem services. Recent data suggest that honey bees appear to be...

Intertemporal Choice of Marine Ecosystem Exploitation

DEFF Research Database (Denmark)

Ravn-Jonsen, Lars

Management, however, requires models that can link the ecosystem level to the operation level, so this paper examines an ecosystem production model and shows that it is suitable for applying ground rent theory. This model is the simplest possible that incorporates the principles of size as the main......, it is probably detrimental from an economic point of view. The marine ecosystem therefore requires an ecosystem management for economic reasons; in this context, models like the one presented here can serve as useful planning tools....... determinant of the predator--prey interaction, the inclusion of mass balance in the predator--prey allocation, and mortality and somatic growth as consequences of the predator--prey allocation. The model needs to be parameterized for the specific ecosystem and the price and cost functions must be established...

Strategy scenario selection in the competition of mobile ecosystems

OpenAIRE

Lee, Hyun Joo; Kim, Jin Ki

2013-01-01

Competition in the mobile market is centered on platforms, or operating systems, for smartphones. The current competition and market structure of the global mobile market has shifted to a competition among ecosystems that utilize the same mobile operating systems of the platform operators. This paper aims to answer those questions. The direction of competition in the smartphone industry is traced. This study tries to list the selectable strategy options for each major ecosystem. Then the stra...

Review of the Operability for the Components Under the Loss of the HVAC System of the Pump Room

International Nuclear Information System (INIS)

Hwang Mee Jeong; Yoon, Churl; Yang, Joon Eon; Park, Joo Hwan

2005-01-01

In this paper, we estimated the temperature of the pump rooms and reviewed the operability of the components under the loss of the HVAC (Heating, Ventilation, and Air Condition) system. The issues relevant to the HVAC system in the PSA (Probabilistic Safety Assessment) FT (Fault Tree) model are as follows: does the loss of the HVAC system bring about a function failure of other components?. Can the operator take action to reduce the temperature of the room in case of a HVAC function failure?. At present we do not know whether a component will lose its function or not under the loss of the HVAC. ASME Standard describes that a recovery action can be credited if the related recovery action is included in the procedure or there are similar recovery experiences in the plant. However, there is no description about the recovery action of the HVAC in the EOP (Emergency Operation Procedure) of the UCN3, 4 under the situation of a loss of the HVAC. Even though we consider this assumption positively, it would be limited to the rooms such as the Switchgear Room, Inverter Room, and Main Control Room etc. where a real recovery action can be performed easily. However, if we consider the HVAC failure in the PSA FT model according to the above background, the problem is that the unavailability induced from the loss of a HVAC is highly unrealistically. From a viewpoint of the PSA, it is not true that the related system always fails even though the HVAC system fails. Therefore, we reviewed the necessity of the HVAC model through the identification of the operable temperature of the components' within the pump room and the change of the temperature of the pump room under the situation of a loss of the HVAC system

26 CFR 1.1502-21 - Net operating losses.

Science.gov (United States)

2010-04-01

..., gain, deduction, and loss, including the member's losses and deductions actually absorbed by the group... income, gain, deduction, and loss. For this purpose— (A) Consolidated taxable income is computed without... the group has no Year 2 capital gain, it cannot absorb any capital losses in Year 2. T's Year 1 net...

Loss on Ignition Furnace Acceptance and Operability Test Procedure

International Nuclear Information System (INIS)

JOHNSTON, D.C.

2000-01-01

The purpose of this Acceptance Test Procedure and Operability Test Procedure (ATP/OTP)is to verify the operability of newly installed Loss on Ignition (LOI) equipment, including a model 1608FL CMTM Furnace, a dessicator, and balance. The operability of the furnace will be verified. The arrangement of the equipment placed in Glovebox 157-3/4 to perform LOI testing on samples supplied from the Thermal Stabilization line will be verified. In addition to verifying proper operation of the furnace, this ATP/OTP will also verify the air flow through the filters, verify a damper setting to establish and maintain the required differential pressure between the glovebox and the room pressure, and test the integrity of the newly installed HEPA filter. In order to provide objective evidence of proper performance of the furnace, the furnace must heat 15 crucibles, mounted on a crucible rack, to 1000 C, according to a program entered into the furnace controller located outside the glovebox. The glovebox differential pressure will be set to provide the 0.5 to 2.0 inches of water (gauge) negative pressure inside the glovebox with an expected airflow of 100 to 125 cubic feet per minute (cfm) through the inlet filter. The glovebox inlet G1 filter will be flow tested to ensure the integrity of the filter connections and the efficiency of the filter medium. The newly installed windows and glovebox extension, as well as all disturbed joints, will be sonically tested via ultra probe to verify no leaks are present. The procedure for DOS testing of the filter is found in Appendix A

Ecosystem Service Changes and Livelihood Impacts in the Maguri-Motapung Wetlands of Assam, India

Directory of Open Access Journals (Sweden)

Laxmi D. Bhatta

2016-06-01

Full Text Available Wetlands provide a diverse range of ecosystem services supporting livelihoods of many people. Despite their value, wetlands are continuously being degraded. There is scant information on individual wetlands, people’s dependency and their exploitation at a local scale. We therefore assessed wetland ecosystem services, the drivers of change and impacts of those drivers on ecosystem services and people’s dependency through a case study of the Maguri-Motapung Beel wetlands of Assam, India. Both qualitative and quantitative data were collected through household surveys, focus group discussions, key informant interviews and community workshops. The analyses showed a total of 29 ecosystem services, and high dependency on these with five out of seven livelihood strategies sourced from ecosystem services. Over-exploitation of wetland resources and siltation were reported as the major direct drivers of change with impacts on both ecosystem services and people’s livelihoods. Drastic decreases in availability of thatch, fish stocks, fodder and tourism were observed. This suggests that there is an urgent need for a comprehensive participatory management plan. Actions are needed to maintain the Maguri-Motapung Beel wetlands and the flow of services in order to sustain people’s livelihoods in the area. With an estimated 50% global loss of wetlands in the last century and the loss of 5,000 square kilometers a year in Asia alone, the loss of ecosystem services and livelihood impacts shown in our study may be typical of what is occurring in the region and perhaps globally.

Biodiversity Impact Assessment of roads: an approach based on ecosystem rarity

International Nuclear Information System (INIS)

Geneletti, Davide

2003-01-01

Biodiversity has become one of the central environmental issues in the framework of recent policies and international conventions for the promotion of sustainable development. The reduction of habitat worldwide is currently considered as the main threat to biodiversity conservation. Transportation infrastructures, and above all road networks, are blamed for highly contributing to the decrease in both the quantity and the quality of natural habitat. Therefore, a sound Biodiversity Impact Assessment (BIA) in road planning and development needs to be coupled to other commonly considered aspects. This paper presents an approach to contribute to BIA of road projects that focuses on one type of impact: the direct loss of ecosystems. The first step consists in mapping the different ecosystem types, and in evaluating their relevance for biodiversity conservation. This is based on the assessment of ecosystem's rarity. Rarity is a measure of how frequently an ecosystem type is found within a given area. Its relevance is confirmed by the fact that the protection of rare ecosystems is often considered as the single most important function of biodiversity conservation. Subsequently, the impact of a road project can be quantified by spatially computing the expected losses of each ecosystem type. To illustrate the applicability of the methodology, a case study is presented dealing with the assessment of alternative routes for a highway development in northern Italy

Numerical Analysis of Loss of Residual Heal Removal System (RHRS) during Mid-Loop Operation for Hanul NPP Units 1 and 2

Energy Technology Data Exchange (ETDEWEB)

Kim, Sook Kwan; Park, Seong Gyu; Han, Sang Koo [ACT Co., Daejeon (Korea, Republic of)

2016-10-15

As a part of supporting LPSD (Low Power and Shutdown) PSA (Probabilistic Safety Assessment) of Hanul NPP units 1 and 2, numerical analysis for a loss of RHRS (Residual Heat Removal system) during midloop operation was performed using RELAP5/MOD3.3 code. The one of main purpose of thermal hydraulic analysis for PSA work is to estimate times allowable for operation actions in each accident. A loss of RHRS during mid-loop operation may cause more significant results than during RCS full condition due to reduced RCS inventory. In order to perform this kind of analysis, it is particularly important to establish a steady state of mid-loop operational initial condition. Mid-loop operation corresponds to POS(Plant Operational State) 5 and 11 in the category of LPSD PSA at Hanul NPP units 1 and 2. RELAP5/MOD3.3 code was used to predict behaviors of RCS and fuels for the case of loss of RHRS during mid-loop operation at Hanul NPP units 1 and 2. The initial state of mid-loop operational condition was established by proper control of charging and letdown flow. Considering existing similar analysis results for this kind of accident, it can be concluded that RELAP5 code well predicts reasonably the behavior of RCS for loss of RHRS during mid-loop operation in Hanul NPP units 1 and 2. Thus the method developed in the analysis can be applied reasonably to support LPSD PSA.

Regression and tracing methodology based prediction of oncoming demand and losses in deregulated operation of power systems

DEFF Research Database (Denmark)

Nallagownden, P.; Mukerjee, R.N.; Masri, S.

2010-01-01

of the transmission services hiring contract, inputs such as extent of use of a transmission circuit for a transaction and the associated power loss in the said transmission circuit are also required. To provide the necessary lead time to frame transaction and transmission contracts for an oncoming operational...... coefficients are used advantageously to predict a generator's contribution to a retailer's demand and power loss for this transaction. This paper proposes a procedure that can be implemented real time, to quantify losses in each transmission circuit used by a specific transaction, based on proportionality......The deregulated electricity market can be thought of as a conglomeration of generation providers, transmission service operators (TSO) and retailers, where both generation and retailing may have open access to the transmission grid for trading electricity. For a transaction contract bid to take...

Operating point resolved loss computation in electrical machines

Directory of Open Access Journals (Sweden)

Pfingsten Georg Von

2016-03-01

Full Text Available Magnetic circuits of electromagnetic energy converters, such as electrical machines, are nowadays highly utilized. This proposition is intrinsic for the magnetic as well as the electric circuit and depicts that significant enhancements of electrical machines are difficult to achieve in the absence of a detailed understanding of underlying effects. In order to improve the properties of electrical machines the accurate determination of the locally distributed iron losses based on idealized model assumptions solely is not sufficient. Other loss generating effects have to be considered and the possibility being able to distinguish between the causes of particular loss components is indispensable. Parasitic loss mechanisms additionally contributing to the total losses originating from field harmonics, non-linear material behaviour, rotational magnetizations, and detrimental effects caused by the manufacturing process or temperature, are not explicitly considered in the common iron-loss models, probably even not specifically contained in commonly used calibration factors. This paper presents a methodology being able to distinguish between different loss mechanisms and enables to individually consider particular loss mechanisms in the model of the electric machine. A sensitivity analysis of the model parameters can be performed to obtain information about which decisive loss origin for which working point has to be manipulated by the electromagnetic design or the control of the machine.

Predicting the consequences of species loss using size-structured biodiversity approaches

DEFF Research Database (Denmark)

Brose, Ulrich; Blanchard, Julia L.; Eklöf, Anna

2017-01-01

Understanding the consequences of species loss in complex ecological communities is one of the great challenges in current biodiversity research. For a long time, this topic has been addressed by traditional biodiversity experiments. Most of these approaches treat species as trait-free, taxonomic...... stability, and (iii) ecosystem functioning. Contrasting current expectations, size-structured approaches suggest that the loss of large species, that typically exploit most resource species, may lead to future food webs that are less interwoven and more structured by chains of interactions and compartments...... trait when analysing the consequences of biodiversity loss for natural ecosystems. Applying size-structured approaches provides an integrative ecological concept that enables a better understanding of each species' unique role across communities and the causes and consequences of biodiversity loss....

Effects of Plant Functional Group Loss on Soil Microbial Community and Litter Decomposition in a Steppe Vegetation.

Science.gov (United States)

Xiao, Chunwang; Zhou, Yong; Su, Jiaqi; Yang, Fan

2017-01-01

Globally, many terrestrial ecosystems are experiencing a rapid loss of biodiversity. Continued improvements in our understanding of interrelationships between plant diversity and soil microbes are critical to address the concern over the consequences of the decline in biodiversity on ecosystem functioning and services. By removing forbs, or grasses, or, to an extreme scenario, both forbs and grasses in a steppe vegetation in Inner Mongolia, we studied how plant functional group (PFG) loss affects soil microbial community composition using phospholipid fatty acid analysis (PLFA) and litter decomposition using a litter-bag method. PFG loss significantly decreased above- and below-ground plant biomass, soil microbial biomass carbon (SMBC) and nitrogen (SMBN), but had no effect on the ratio of SMBC to SMBN. Although the ratio of fungal to bacterial PLFAs remained unaffected, PFG loss significantly reduced the amount of bacterial, fungal, and total PLFAs. PFG loss decreased litter monthly mass loss and decay constant, and such decrease was significant when both forbs and grasses were removed. Our results provide robust evidence that PFG loss in grassland ecosystem can lead to a rapid response of soil microbial activity which may affect litter decomposition and soil nutrient cycling, suggesting that the assessment of plant-microbe interactions in soils is an integral component of ecosystem response to biodiversity loss.

Rare species support vulnerable functions in high-diversity ecosystems.

Directory of Open Access Journals (Sweden)

David Mouillot

Full Text Available Around the world, the human-induced collapses of populations and species have triggered a sixth mass extinction crisis, with rare species often being the first to disappear. Although the role of species diversity in the maintenance of ecosystem processes has been widely investigated, the role of rare species remains controversial. A critical issue is whether common species insure against the loss of functions supported by rare species. This issue is even more critical in species-rich ecosystems where high functional redundancy among species is likely and where it is thus often assumed that ecosystem functioning is buffered against species loss. Here, using extensive datasets of species occurrences and functional traits from three highly diverse ecosystems (846 coral reef fishes, 2,979 alpine plants, and 662 tropical trees, we demonstrate that the most distinct combinations of traits are supported predominantly by rare species both in terms of local abundance and regional occupancy. Moreover, species that have low functional redundancy and are likely to support the most vulnerable functions, with no other species carrying similar combinations of traits, are rarer than expected by chance in all three ecosystems. For instance, 63% and 98% of fish species that are likely to support highly vulnerable functions in coral reef ecosystems are locally and regionally rare, respectively. For alpine plants, 32% and 89% of such species are locally and regionally rare, respectively. Remarkably, 47% of fish species and 55% of tropical tree species that are likely to support highly vulnerable functions have only one individual per sample on average. Our results emphasize the importance of rare species conservation, even in highly diverse ecosystems, which are thought to exhibit high functional redundancy. Rare species offer more than aesthetic, cultural, or taxonomic diversity value; they disproportionately increase the potential breadth of functions provided by

Estimating net ecosystem exchange of carbon using the normalized difference vegetation index and an ecosystem model

International Nuclear Information System (INIS)

Veroustraete, F.; Patyn, J.; Myneni, R.B.

1996-01-01

The evaluation and prediction of changes in carbon dynamics at the ecosystem level is a key issue in studies of global change. An operational concept for the determination of carbon fluxes for the Belgian territory is the goal of the presented study. The approach is based on the integration of remotely sensed data into ecosystem models in order to evaluate photosynthetic assimilation and net ecosystem exchange (NEE). Remote sensing can be developed as an operational tool to determine the fraction of absorbed photosynthetically active radiation (feAR). A review of the methodological approach of mapping fPAR dynamics at the regional scale by means of NOAA11-A VHRR / 2 data for the year 1990 is given. The processing sequence from raw radiance values to fPAR is presented. An interesting aspect of incorporating remote sensing derived fPAR in ecosystem models is the potential for modeling actual as opposed to potential vegetation. Further work should prove whether the concepts presented and the assumptions made in this study are valid. (NEE). Complex ecosystem models with a highly predictive value for a specific ecosystem are generally not suitable for global or regional applications, since they require a substantial set of ancillary data becoming increasingly larger with increasing complexity of the model. The ideal model for our purpose is one that is simple enough to be used in global scale modeling, and which can be adapted for different ecosystems or vegetation types. The fraction of absorbed photosynthetically active radiation (fPAR) during the growing season determines in part net photosynthesis and phytomass production (Ruimy, 1995). Remotely measured red and near-infrared spectral reflectances can be used to estimate fPAR. Therefore, a possible approach is to estimate net photosynthesis, phytomass, and NEE from a combination of satellite data and an ecosystem model that includes carbon dynamics. It has to be stated that some parts of the work presented in this

Small but powerful: top predator local extinction affects ecosystem structure and function in an intermittent stream.

Science.gov (United States)

Rodríguez-Lozano, Pablo; Verkaik, Iraima; Rieradevall, Maria; Prat, Narcís

2015-01-01

Top predator loss is a major global problem, with a current trend in biodiversity loss towards high trophic levels that modifies most ecosystems worldwide. Most research in this area is focused on large-bodied predators, despite the high extinction risk of small-bodied freshwater fish that often act as apex consumers. Consequently, it remains unknown if intermittent streams are affected by the consequences of top-predators' extirpations. The aim of our research was to determine how this global problem affects intermittent streams and, in particular, if the loss of a small-bodied top predator (1) leads to a 'mesopredator release', affects primary consumers and changes whole community structures, and (2) triggers a cascade effect modifying the ecosystem function. To address these questions, we studied the top-down effects of a small endangered fish species, Barbus meridionalis (the Mediterranean barbel), conducting an enclosure/exclosure mesocosm experiment in an intermittent stream where B. meridionalis became locally extinct following a wildfire. We found that top predator absence led to 'mesopredator release', and also to 'prey release' despite intraguild predation, which contrasts with traditional food web theory. In addition, B. meridionalis extirpation changed whole macroinvertebrate community composition and increased total macroinvertebrate density. Regarding ecosystem function, periphyton primary production decreased in apex consumer absence. In this study, the apex consumer was functionally irreplaceable; its local extinction led to the loss of an important functional role that resulted in major changes to the ecosystem's structure and function. This study evidences that intermittent streams can be affected by the consequences of apex consumers' extinctions, and that the loss of small-bodied top predators can lead to large ecosystem changes. We recommend the reintroduction of small-bodied apex consumers to systems where they have been extirpated, to restore

Small but powerful: top predator local extinction affects ecosystem structure and function in an intermittent stream.

Directory of Open Access Journals (Sweden)

Pablo Rodríguez-Lozano

Full Text Available Top predator loss is a major global problem, with a current trend in biodiversity loss towards high trophic levels that modifies most ecosystems worldwide. Most research in this area is focused on large-bodied predators, despite the high extinction risk of small-bodied freshwater fish that often act as apex consumers. Consequently, it remains unknown if intermittent streams are affected by the consequences of top-predators' extirpations. The aim of our research was to determine how this global problem affects intermittent streams and, in particular, if the loss of a small-bodied top predator (1 leads to a 'mesopredator release', affects primary consumers and changes whole community structures, and (2 triggers a cascade effect modifying the ecosystem function. To address these questions, we studied the top-down effects of a small endangered fish species, Barbus meridionalis (the Mediterranean barbel, conducting an enclosure/exclosure mesocosm experiment in an intermittent stream where B. meridionalis became locally extinct following a wildfire. We found that top predator absence led to 'mesopredator release', and also to 'prey release' despite intraguild predation, which contrasts with traditional food web theory. In addition, B. meridionalis extirpation changed whole macroinvertebrate community composition and increased total macroinvertebrate density. Regarding ecosystem function, periphyton primary production decreased in apex consumer absence. In this study, the apex consumer was functionally irreplaceable; its local extinction led to the loss of an important functional role that resulted in major changes to the ecosystem's structure and function. This study evidences that intermittent streams can be affected by the consequences of apex consumers' extinctions, and that the loss of small-bodied top predators can lead to large ecosystem changes. We recommend the reintroduction of small-bodied apex consumers to systems where they have been

Incorporating Ecosystem Services into Community-level ...

Science.gov (United States)

EPA’s Office of Research and Development’s Sustainable and Healthy Communities Research Program is developing tools and approaches to incorporate ecosystem goods and services concepts into community-level decision-making. The San Juan Community Study is one of a series of coordinated community studies, which also include Mobile Bay, AL, Great Lakes Areas of Concern, and the Pacific Northwest. Common elements across the community studies include a focus on watershed management and national estuary programs (National Estuary Program, National Estuarine Research Reserve System). San Juan, Puerto Rico, is unique from the other community studies in that it is located in a highly urbanized watershed integrated with a number of freshwater and coastal ecosystems. The San Juan Community Study will explore linkages between watershed management decisions (e.g., dredging canals, restoration of mangrove buffers, sewage discharge interventions, climate adaptive strategies) targeting priority stressors (e.g., nutrients, contaminants, and pathogens; aquatic debris; habitat loss; modified hydrology and water circulation; sea level rise; storm intensity and frequency) effecting the condition of ecosystems (e.g., estuarine habitats and fish, as well as the connected terrestrial and coastal ecosystems), associated ecosystem goods and services (e.g., tourism and recreation, fishing, nutrient & sediment retention, contaminant processing, carbon sequestration, flood protection),

Tipping elements in the Arctic marine ecosystem.

Science.gov (United States)

Duarte, Carlos M; Agustí, Susana; Wassmann, Paul; Arrieta, Jesús M; Alcaraz, Miquel; Coello, Alexandra; Marbà, Núria; Hendriks, Iris E; Holding, Johnna; García-Zarandona, Iñigo; Kritzberg, Emma; Vaqué, Dolors

2012-02-01

The Arctic marine ecosystem contains multiple elements that present alternative states. The most obvious of which is an Arctic Ocean largely covered by an ice sheet in summer versus one largely devoid of such cover. Ecosystems under pressure typically shift between such alternative states in an abrupt, rather than smooth manner, with the level of forcing required for shifting this status termed threshold or tipping point. Loss of Arctic ice due to anthropogenic climate change is accelerating, with the extent of Arctic sea ice displaying increased variance at present, a leading indicator of the proximity of a possible tipping point. Reduced ice extent is expected, in turn, to trigger a number of additional tipping elements, physical, chemical, and biological, in motion, with potentially large impacts on the Arctic marine ecosystem.

Prairie dog decline reduces the supply of ecosystem services and leads to desertification of semiarid grasslands.

Directory of Open Access Journals (Sweden)

Lourdes Martínez-Estévez

Full Text Available Anthropogenic impacts on North American grasslands, a highly endangered ecosystem, have led to declines of prairie dogs, a keystone species, over 98% of their historical range. While impacts of this loss on maintenance of grassland biodiversity have been widely documented, much less is known about the consequences on the supply of ecosystem services. Here we assessed the effect of prairie dogs in the supply of five ecosystem services by comparing grasslands currently occupied by prairie dogs, grasslands devoid of prairie dogs, and areas that used to be occupied by prairie dogs that are currently dominated by mesquite scrub. Groundwater recharge, regulation of soil erosion, regulation of soil productive potential, soil carbon storage and forage availability were consistently quantitatively or qualitatively higher in prairie dog grasslands relative to grasslands or mesquite scrub. Our findings indicate a severe loss of ecosystem services associated to the absence of prairie dogs. These findings suggest that contrary to a much publicize perception, especially in the US, prairie dogs are fundamental in maintaining grasslands and their decline have strong negative impacts in human well - being through the loss of ecosystem services.

Strategies for conservation of endangered ecosystems

International Nuclear Information System (INIS)

Ashraf, M.; Hussain, M.; Ahmad, M.S.A.

2012-01-01

The planet Earth is known to host a rich biodiversity owing to its suitable environmental conditions for life and at a larger scale it is regarded as a major ecosystem. Healthy existence of living organisms in this ecosystem depends on proper functioning of all the associated environmental factors. Since millennia, living organisms have adapted to thrive under a limited range of environmental conditions. Nevertheless previous history of the earth and fossil records indicates that the biodiversity housed by the planet earth has experienced five major catastrophic extinctions due to change in physical environment. Even currently, it is undergoing sixth major extinction event mainly due to anthropogenic activities. The human activities are proving a dual menace for biodiversity. On the one hand, it is causing habitat loss through intensive deforestation, conversion of different natural plant communities for agriculture, and urbanization and industrialization. Moreover, it is resulting in habitat degradation by polluting both terrestrial and aquatic ecosystems, emitting air pollutants resulting in acid rains, ozone layer depletion, global warming, heavy metal contamination and eutrophication of water bodies. As a result, healthy existence of both terrestrial and aquatic ecosystems and their associated biodiversity is altogether threatened. Worldwide efforts are underway to conserve the threatened ecosystems and their related biodiversity. A number of international conventions have been held to conserve natural ecosystems. Pakistan being a signatory of these conventions has its obligation to join hands with international community to conserve the endangered ecosystems within as well as outside its bounds. Under the existing scenario the objective of organizing this symposium was to pinpoint the threats to endangered ecosystems of the world in general and those in Pakistan in particular, and to develop suitable strategies for conservation of such paralyzed ecosystems

Proving the ecosystem value through hydrological modelling

International Nuclear Information System (INIS)

Dorner, W; Spachinger, K; Metzka, R; Porter, M

2008-01-01

Ecosystems provide valuable functions. Also natural floodplains and river structures offer different types of ecosystem functions such as habitat function, recreational area and natural detention. From an economic stand point the loss (or rehabilitation) of these natural systems and their provided natural services can be valued as a damage (or benefit). Consequently these natural goods and services must be economically valued in project assessments e.g. cost-benefit-analysis or cost comparison. Especially in smaller catchments and river systems exists significant evidence that natural flood detention reduces flood risk and contributes to flood protection. Several research projects evaluated the mitigating effect of land use, river training and the loss of natural flood plains on development, peak and volume of floods. The presented project analysis the hypothesis that ignoring natural detention and hydrological ecosystem services could result in economically inefficient solutions for flood protection and mitigation. In test areas, subcatchments of the Danube in Germany, a combination of hydrological and hydrodynamic models with economic evaluation techniques was applied. Different forms of land use, river structure and flood protection measures were assed and compared from a hydrological and economic point of view. A hydrodynamic model was used to simulate flows to assess the extent of flood affected areas and damages to buildings and infrastructure as well as to investigate the impacts of levees and river structure on a local scale. These model results provided the basis for an economic assessment. Different economic valuation techniques, such as flood damage functions, cost comparison method and substation-approach were used to compare the outcomes of different hydrological scenarios from an economic point of view and value the ecosystem service. The results give significant evidence that natural detention must be evaluated as part of flood mitigation projects

[Dynamic changes of Ruoergai Plateau wetland ecosystem service value].

Science.gov (United States)

Zhang, Xiao-Yun; Lü, Xian-Guo; Shen, Song-Ping

2009-05-01

Based on the satellite remote sensing data acquired in 1975 and 2006, and by using the assessment method of ecosystem service value, the dynamic changes of physical production value, gas regulation value, and water storage value of Ruoergai Plateau wetland ecosystem in 1975-2006 were studied. During study period, the total value of the three services decreased from 19.59 billion RMB Yuan to 12.38 billion Yuan RMB, among which, physical production value increased by 0.302 billion RMB Yuan, while the gas regulation and water storage value decreased by 7.507 billion RMB Yuan. The benefit from the increase of physical production was much less than the loss of ecosystem degradation. Overgrazing induced the biomass reduction and soil deterioration, resulting in the decline of Ruoergai Plateau wetland ecosystem service value and service capacity.

Identification and ranking of environmental threats with ecosystem vulnerability distributions.

Science.gov (United States)

Zijp, Michiel C; Huijbregts, Mark A J; Schipper, Aafke M; Mulder, Christian; Posthuma, Leo

2017-08-24

Responses of ecosystems to human-induced stress vary in space and time, because both stressors and ecosystem vulnerabilities vary in space and time. Presently, ecosystem impact assessments mainly take into account variation in stressors, without considering variation in ecosystem vulnerability. We developed a method to address ecosystem vulnerability variation by quantifying ecosystem vulnerability distributions (EVDs) based on monitoring data of local species compositions and environmental conditions. The method incorporates spatial variation of both abiotic and biotic variables to quantify variation in responses among species and ecosystems. We show that EVDs can be derived based on a selection of locations, existing monitoring data and a selected impact boundary, and can be used in stressor identification and ranking for a region. A case study on Ohio's freshwater ecosystems, with freshwater fish as target species group, showed that physical habitat impairment and nutrient loads ranked highest as current stressors, with species losses higher than 5% for at least 6% of the locations. EVDs complement existing approaches of stressor assessment and management, which typically account only for variability in stressors, by accounting for variation in the vulnerability of the responding ecosystems.

Risk and markets for ecosystem services.

Science.gov (United States)

Bendor, Todd K; Riggsbee, J Adam; Doyle, Martin

2011-12-15

Market-based environmental regulations (e.g., cap and trade, "payments for ecosystem services") are increasingly common. However, few detailed studies of operating ecosystem markets have lent understanding to how such policies affect incentive structures for improving environmental quality. The largest U.S. market stems from the Clean Water Act provisions requiring ecosystem restoration to offset aquatic ecosystems damaged during development. We describe and test how variations in the rules governing this ecosystem market shift risk between regulators and entrepreneurs to promote ecological restoration. We analyze extensive national scale data to assess how two critical aspects of market structure - (a) the geographic scale of markets and (b) policies dictating the release of credits - affect the willingness of entrepreneurs to enter specific markets and produce credits. We find no discernible relationship between policies attempting to ease market entry and either the number of individual producers or total credits produced. Rather, market entry is primarily related to regional geography (the prevalence of aquatic ecosystems) and regional economic growth. Any improvements to policies governing ecosystem markets require explicit evaluation of the interplay between policy and risk elements affecting both regulators and entrepreneurial credit providers. Our findings extend to emerging, regulated ecosystem markets, including proposed carbon offset mechanisms, biodiversity banking, and water quality trading programs.

Assessing the Impact of Landscape Development on Ecosystem Services Value in Tropical Watershed

Science.gov (United States)

Foo, Y. S.; Hashim, M.

2014-02-01

As development increases with demand, more forest lands are replaced with cropland, commercial plantation, and infrastructures for being able to accommodate the excessive growth in world's population. Environments were destroyed without considering their values in sustaining life on Earth.This phenomenon is still an ongoing scenario in most of the developing countries in the tropical region including Malaysia. Such unrestricted conversion may cause food or water crisis along with irreparable consequences to local and regional climate as the natural ecosystem is not only the main resources generator but also the climate stabilizer. Contrary to this, a study was conducted in Pahang Watershed, the largest watershed in Peninsular Malaysia with forest as the dominant land cover, to investigate the effect of landscape development on the ecosystem in terms of the erosion and ecosystem service value. Results of soil loss based on USLE indicated a direct relationship between development and total soil loss where total annual soil loss in year 2005 and 2010 showed a significant increase compare to year 2000. Meanwhile, developed and agricultural lands were discovered to be the main contributor whereas forest land produce the least soil loss (oil palm had become the main commercial plantation in current years, the commercial profit brought by oil palm still insufficient to cover losses referring to overall estimated ESVG due to the forest clearance and soil degradation. In addition, for a destroyed ecosystem to be equilibrium again requires years. Therefore, ESVG of the tropical forest are expected to increase continuously in future which mean that the roles of the forest in conserving the environment stabilization and sustainability of life are getting more critical.

Generic evaluation of feedwater transients and small break loss-of-coolant accidents in GE-designed operating plants and near-term operating license applications

International Nuclear Information System (INIS)

1980-01-01

The results are presented of a generic evaluation of feedwater transients, small-break loss-of-coolant accidents (LOCAs), and other TMI-2-related events for General Electric Company (GE)-designed operating plants and near-term operating license applications to confirm or establish the bases for the continued safe operation of the operating plants. The results of this evaluation are presented in this report in the form of a set of findings and recommendations in each of the principal review areas. Additional review of the accident is continuing and further information is being obtained and evaluated. Any new information will be reviewed and modifications will be made as appropriate

Assessing Niger-Delta Wetland Resources: A Case-Study of Mangrove Ecosystem

Science.gov (United States)

Anwan, R. H.; Ndimele, P. E.; Whenu, O. O.; Anetekhai, M. A.; Essien-Ibok, M. A.; Erondu, E. S.

2016-02-01

The Niger Delta is located in the Atlantic coast of Southern Nigeria and is the world's second largest delta with a coastline of about 450km. The Niger Delta region occupies a surface area of about 112,110km2, representing about 12% of Nigeria's total surface area. The Delta's environment can be broken down into four ecological zones: coastal barrier islands, mangrove swamp forests, freshwater swamps, and lowland rainforests. The mangrove swamps of Niger Delta, which is the largest delta in Africa constitute the dominant wetland ecosystem in the Niger Delta region and covers an area of about 1,900km2. Mangroves constitute important nurseries for fishes, crustaceans, sponges, algae and other invertebrates, and also acts as a sink, retaining pollutants from contaminated tidal water. The Niger Delta mangrove together with the creeks and rivers are a major source of food and livelihood for about 30 million people, which represents more than 17% of Nigeria's population. Other ecosystem services provided by this unique environment are flood control, ground water re-fill, reservoir of biodiversity, fuel wood, cultural values etc. This ecosystem also plays important role in climate change mitigation because of its high blue carbon sequestration potential. This is particularly important because of continuous gas flaring in Niger Delta from petroleum operations, which releases carbon dioxide among other gases into the atmosphere. This wetland is potentially a good site for ecotourism and also qualifies to be a world heritage site and Ramsar site if proper steps are taken. The benefits derivable from this fragile ecosystem are under severe threat by anthropogenic stressors. These include the installation of pipelines and seismic exploration by oil companies, crude oil pollution, deforestation, urbanization etc. This paper discusses the extent of depletion and loss of mangrove ecosystem in the Niger Delta region and the value of its goods and services.

Nutrient losses in forest plantations in Sabah, Malaysia

International Nuclear Information System (INIS)

Nykvist, N.; Grip, A.; Malmer, A.

1994-01-01

Inorganic nutrients are lost from terrestrial ecosystems through the harvesting of plant products, leaching, soil erosion and volatilization of nitrogen and sulfur compounds. In this study, carried out in a tropical rain forest ecosystem in Sabah, Malaysia, losses of inorganic nutrients through log removal and runoff/leaching to stream water were compared in clear-fellings, harvested and prepared for planting in two different ways: (i) tractor logging/burning; (ii) and manual logging/no burning. The major findings of the study were that nutrient losses in stream water were reduced by 50% and growth of the planted forest was twice as fast on the catchment where soil disturbance was minimized and burning not used. Weeds were more abundant after burning, and the extra weeding needed increased costs for plantation establishment. Ways of decreasing the loss of inorganic nutrients when clear-felling tropical rain forests are discussed. 32 refs, 4 figs, 3 tabs

Evaluation of the performance degradation at PAFC effect of operating conditions on acid loss

Energy Technology Data Exchange (ETDEWEB)

Miyoshi, Hideaki; Uchida, Hiroyuki; Watanabe, Masahiro [Yamanashi Univ., Kofu (Japan)] [and others

1996-12-31

As a complimentary research project to the demonstration project of 5MW and 1 MW PAFC plants, the mechanism and rate of deterioration of the cells and stacks have been studied from 1995 FY conducted by NEDO, with the objective of establishing an estimation method for the service life-time of the cell stacks. As part of this project, this work has been performed to clarify basic phenomena of the performance degradation at PAFCs jointly by Yamanashi University, PAFC-TRA and PAFC manufacturers. The acid loss into exhaust gases is one of life limiting factors in PAFCs. To design the cells of long-life, it is important to estimate the phosphoric acid loss and to contrive ideas eliminating it. With the objective of obtaining basic data for simulating the acid loss in the large size cells, the effect of the operating conditions on the acid loss into exhaust gases has been studied experimentally by using a single cell with an active electrode area of 100 cm{sup 2}.

Amphibians in the climate vise: loss and restoration of resilience of montane wetland ecosystems in the western US

Science.gov (United States)

Ryan, Maureen E.; Palen, Wendy J.; Adams, Michael J.; Rochefort, Regina M.

2014-01-01

Wetlands in the remote mountains of the western US have undergone two massive ecological “experiments” spanning the 20th century. Beginning in the late 1800s and expanding after World War II, fish and wildlife managers intentionally introduced millions of predatory trout (primarily Oncorhynchus spp) into fishless mountain ponds and lakes across the western states. These new top predators, which now occupy 95% of large mountain lakes, have limited the habitat distributions of native frogs, salamanders, and wetland invertebrates to smaller, more ephemeral ponds where trout do not survive. Now a second “experiment” – anthropogenic climate change – threatens to eliminate many of these ephemeral habitats and shorten wetland hydroperiods. Caught between climate-induced habitat loss and predation from introduced fish, native mountain lake fauna of the western US – especially amphibians – are at risk of extirpation. Targeted fish removals, guided by models of how wetlands will change under future climate scenarios, provide innovative strategies for restoring resilience of wetland ecosystems to climate change.

Identifying pelagic ecosystem indicators for management

DEFF Research Database (Denmark)

Trenkel, Verena; Hintzen, Niels; Rindorf, Anna

2013-01-01

When exploiting fish populations under the ecosystem approach, aiming for MSY is not necessarily sufficient to ensure wider ecosystem sustainability. All of the large stocks of pelagic fish are managed through harvest control rules based on an MSY approach. Ensuring good environmental status...... will probably require further constraints to be imposed by management. Most of the current paradigm with regards to GES for fisheries has been based on demersal fish. Pelagic fisheries and fish are operationally and biologically respectively different. We use the example of applying the ecosystem approach...... between objectives and indicators were explored for a range of examples highlighting the importance of the biology and the interaction between the pelagic ecosystem and humans. Considering MSY targets alone will not fulfil GES objectives with regards to e.g. genetic, phenotypic, and behavioural dimensions...

From bacteria to elephants: Effects of land-use legacies on biodiversity and ecosystem structure in the Serengeti-Mara ecosystem: Chapter 8

Science.gov (United States)

Verchot, Louis V.; Ward, Naomi L.; Belnap, Jayne; Bossio, Deborah; Coughenour, Michael; Gibson, John; Hanotte, Olivier; Muchiru, Andrew N.; Phillips, Susan L.; Steven, Blaire; Wall, Diana H.; Reid, Robin S.

2015-01-01

Generally, ecological research has considered the aboveground and belowground components of ecosystems separately. Consequently, frameworks for integrating the two components are not well developed. Integrating the microbial components into ecosystem ecology requires different approaches from those offered by plant ecology, partly because of the scales at which microbial processes operate and partly because of measurement constraints. Studies have begun to relate microbial community structure to ecosystem function. results suggest that excluding people and livestock from the MMNR, or preventing heavier livestock from grazing around settlements, may not change the general structure of the ecosystem (soils, plant structure), but can change the numbers and diversity of wildlife, nematodes and microbes in this ecosystem in subtle ways.

Effects of Climate and Ecosystem Disturbances on Biogeochemical Cycling in a Semi-Natural Terrestrial Ecosystem

International Nuclear Information System (INIS)

Beier, Claus; Schmidt, Inger Kappel; Kristensen, Hanne Lakkenborg

2004-01-01

The effects of increased temperature and potential ecosystem disturbances on biogeochemical cycling were investigated by manipulation of temperature in a mixed Calluna/grass heathland in Denmark. A reflective curtain covered the vegetation during the night to reduce the heat loss of IR radiation from the ecosystem to the atmosphere. This 'night time warming' was done for 3 years and warmed the air and soil by 1.1 deg. C. Warming was combined with ecosystem disturbances, including infestation by Calluna heather beetles (Lochmaea suturalis Thompson) causing complete defoliation of Calluna leaves during the summer 2000, and subsequent harvesting of all aboveground biomass during the autumn. Small increases in mineralisation rates were induced by warming and resulted in increased leaching of nitrogen from the organic soil layer. The increased nitrogen leaching from the organic soil layer was re-immobilised in the mineral soil layer as warming stimulated plant growth and thereby increased nitrogen immobilisation. Contradictory to the generally moderate effects of warming, the heather beetle infestation had very strong effects on mineralisation rates and the plant community. The grasses completely out-competed the Calluna plants which had not re-established two years after the infestation, probably due to combined effects of increased nutrient availability and the defoliation of Calluna. On the short term, ecosystem disturbances may have very strong effects on internal ecosystem processes and plant community structure compared to the more long-term effects of climate change

Whole-system nutrient enrichment increases secondary production in a detritus-based ecosystem

Science.gov (United States)

W.F. Cross; J.B. Wallace; A.D. Rosemond; S.L. Eggert

2006-01-01

Although the effects of nutrient enrichment on consumer-resource dynamics are relatively well studied in ecosystems based on living plants, little is known about the manner in which enrichment influences the dynamics and productivity of consumers and resources in detritus-based ecosystems. Because nutrients can stimulate loss of carbon at the base of detrital food webs...

Dimensions of ecosystem management: a system approach to policy formulation.

Science.gov (United States)

A.B. Carey

1998-01-01

For the past sixty years, ecologists have been arguing about what an ecosystem is, and the debate continues (Blew 1996; Lenz and Haber 1996). Ecosystem management, however, is an entirely human process that entails not only manipulating and protecting ecosystems but also making private and public goals operational within a larger social environment of public needs,...

Integrating community assembly and biodiversity to better understand ecosystem function: the Community Assembly and the Functioning of Ecosystems (CAFE) approach.

Science.gov (United States)

Bannar-Martin, Katherine H; Kremer, Colin T; Ernest, S K Morgan; Leibold, Mathew A; Auge, Harald; Chase, Jonathan; Declerck, Steven A J; Eisenhauer, Nico; Harpole, Stanley; Hillebrand, Helmut; Isbell, Forest; Koffel, Thomas; Larsen, Stefano; Narwani, Anita; Petermann, Jana S; Roscher, Christiane; Cabral, Juliano Sarmento; Supp, Sarah R

2018-02-01

The research of a generation of ecologists was catalysed by the recognition that the number and identity of species in communities influences the functioning of ecosystems. The relationship between biodiversity and ecosystem functioning (BEF) is most often examined by controlling species richness and randomising community composition. In natural systems, biodiversity changes are often part of a bigger community assembly dynamic. Therefore, focusing on community assembly and the functioning of ecosystems (CAFE), by integrating both species richness and composition through species gains, losses and changes in abundance, will better reveal how community changes affect ecosystem function. We synthesise the BEF and CAFE perspectives using an ecological application of the Price equation, which partitions the contributions of richness and composition to function. Using empirical examples, we show how the CAFE approach reveals important contributions of composition to function. These examples show how changes in species richness and composition driven by environmental perturbations can work in concert or antagonistically to influence ecosystem function. Considering how communities change in an integrative fashion, rather than focusing on one axis of community structure at a time, will improve our ability to anticipate and predict changes in ecosystem function. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Millennium Ecosystem Assessment: MA Ecosystems

Data.gov (United States)

National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Ecosystems provides data and information on the extent and classification of ecosystems circa 2000, including coastal,...

Estimation and comparison of intra operative blood loss in patients with and without venous thromboembolism prophylaxis

International Nuclear Information System (INIS)

Ahsin, S.; Bashir, A.; Faiz, S.A.; Tahir, J.; Ijaz, A.

2014-01-01

To estimate and compare intraoperative blood loss in surgical patients with and without deep vein thrombosis (DVT) prophylaxis using unfractionated heparin Study Design: Clinical Trial Place and Duration: Surgery Department of Fauji Foundation Hospital and Physiology Department Foundation University Medical College from October 2011 to August 2012 Patients and Methodology: Patients were selected by non probability purposive sampling. Patients fulfilling the inclusion criteria were divided into 2 groups 25 each on the basis of order of presentation at Fauji Foundation Hospital until cohort numbers were reached. Group I received no heparin whereas group II received heparin. Written informed consent was taken from the patient after explaining the procedure of the study. Coagulation profile was done for both groups before the planned surgery. Heparin in a dose of 5000 units was administered subcutaneously to group II on the morning of the planned surgery and it was stopped 24 hours post operatively. Blood loss was estimated in both groups by weighing cotton swabs pre and post operatively. Data was analyzed by SPSS version 17. Results: Demographic data and surgical procedure time between the two groups did not differ. Blood loss between the two groups did not show any statistically significant difference. Conclusion: DVT prophylaxis using unfractionated heparin did not lead to any significant overt blood loss when compared with those without it. (author)

How Does Tree Density Affect Water Loss of Peatlands? A Mesocosm Experiment

NARCIS (Netherlands)

Limpens, J.; Holmgren, M.; Jacobs, C.M.J.; Zee, van der S.E.A.T.M.; Karofeld, E.; Berendse, F.

2014-01-01

Raised bogs have accumulated more atmospheric carbon than any other terrestrial ecosystem on Earth. Climate-induced expansion of trees and shrubs may turn these ecosystems from net carbon sinks into sources when associated with reduced water tables. Increasing water loss through tree

Nitrogen Cycling from Increased Soil Organic Carbon Contributes Both Positively and Negatively to Ecosystem Services in Wheat Agro-Ecosystems

Directory of Open Access Journals (Sweden)

Jeda Palmer

2017-05-01

Full Text Available Soil organic carbon (SOC is an important and manageable property of soils that impacts on multiple ecosystem services through its effect on soil processes such as nitrogen (N cycling and soil physical properties. There is considerable interest in increasing SOC concentration in agro-ecosystems worldwide. In some agro-ecosystems, increased SOC has been found to enhance the provision of ecosystem services such as the provision of food. However, increased SOC may increase the environmental footprint of some agro-ecosystems, for example by increasing nitrous oxide emissions. Given this uncertainty, progress is needed in quantifying the impact of increased SOC concentration on agro-ecosystems. Increased SOC concentration affects both N cycling and soil physical properties (i.e., water holding capacity. Thus, the aim of this study was to quantify the contribution, both positive and negative, of increased SOC concentration on ecosystem services provided by wheat agro-ecosystems. We used the Agricultural Production Systems sIMulator (APSIM to represent the effect of increased SOC concentration on N cycling and soil physical properties, and used model outputs as proxies for multiple ecosystem services from wheat production agro-ecosystems at seven locations around the world. Under increased SOC, we found that N cycling had a larger effect on a range of ecosystem services (food provision, filtering of N, and nitrous oxide regulation than soil physical properties. We predicted that food provision in these agro-ecosystems could be significantly increased by increased SOC concentration when N supply is limiting. Conversely, we predicted no significant benefit to food production from increasing SOC when soil N supply (from fertiliser and soil N stocks is not limiting. The effect of increasing SOC on N cycling also led to significantly higher nitrous oxide emissions, although the relative increase was small. We also found that N losses via deep drainage were

Nitrogen Cycling from Increased Soil Organic Carbon Contributes Both Positively and Negatively to Ecosystem Services in Wheat Agro-Ecosystems.

Science.gov (United States)

Palmer, Jeda; Thorburn, Peter J; Biggs, Jody S; Dominati, Estelle J; Probert, Merv E; Meier, Elizabeth A; Huth, Neil I; Dodd, Mike; Snow, Val; Larsen, Joshua R; Parton, William J

2017-01-01

Soil organic carbon (SOC) is an important and manageable property of soils that impacts on multiple ecosystem services through its effect on soil processes such as nitrogen (N) cycling and soil physical properties. There is considerable interest in increasing SOC concentration in agro-ecosystems worldwide. In some agro-ecosystems, increased SOC has been found to enhance the provision of ecosystem services such as the provision of food. However, increased SOC may increase the environmental footprint of some agro-ecosystems, for example by increasing nitrous oxide emissions. Given this uncertainty, progress is needed in quantifying the impact of increased SOC concentration on agro-ecosystems. Increased SOC concentration affects both N cycling and soil physical properties (i.e., water holding capacity). Thus, the aim of this study was to quantify the contribution, both positive and negative, of increased SOC concentration on ecosystem services provided by wheat agro-ecosystems. We used the Agricultural Production Systems sIMulator (APSIM) to represent the effect of increased SOC concentration on N cycling and soil physical properties, and used model outputs as proxies for multiple ecosystem services from wheat production agro-ecosystems at seven locations around the world. Under increased SOC, we found that N cycling had a larger effect on a range of ecosystem services (food provision, filtering of N, and nitrous oxide regulation) than soil physical properties. We predicted that food provision in these agro-ecosystems could be significantly increased by increased SOC concentration when N supply is limiting. Conversely, we predicted no significant benefit to food production from increasing SOC when soil N supply (from fertiliser and soil N stocks) is not limiting. The effect of increasing SOC on N cycling also led to significantly higher nitrous oxide emissions, although the relative increase was small. We also found that N losses via deep drainage were minimally

Photodegradation alleviates the lignin bottleneck for carbon turnover in terrestrial ecosystems.

Science.gov (United States)

Austin, Amy T; Méndez, M Soledad; Ballaré, Carlos L

2016-04-19

A mechanistic understanding of the controls on carbon storage and losses is essential for our capacity to predict and mitigate human impacts on the global carbon cycle. Plant litter decomposition is an important first step for carbon and nutrient turnover, and litter inputs and losses are essential in determining soil organic matter pools and the carbon balance in terrestrial ecosystems. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in arid lands; however, the global significance of this process as a control on carbon cycling in terrestrial ecosystems is not known. Here we show that, across a wide range of plant species, photodegradation enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility to plant litter carbohydrates for microbial enzymes. Photodegradation of plant litter, driven by UV radiation, and especially visible (blue-green) light, reduced the structural and chemical bottleneck imposed by lignin in secondary cell walls. In leaf litter from woody species, specific interactions with UV radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized effect of sunlight exposure on subsequent microbial activity, mediated by increased accessibility to cell wall polysaccharides, suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release, and the carbon balance in a broad range of terrestrial ecosystems.

Estimation of hysteretic losses for MgB2 tapes under the operating conditions of a generator

Science.gov (United States)

Vargas-Llanos, Carlos Roberto; Zermeño, Víctor M. R.; Sanz, Santiago; Trillaud, Frederic; Grilli, Francesco

2016-03-01

Hysteretic losses in the MgB2 wound superconducting coils of a 550 kW synchronous hybrid scaled generator were estimated as part of the European project SUPRAPOWER led by the Spanish Fundación Tecnalia Research & Innovation. Particular interest was given to the losses caused by the magnetic flux ripples in the rotor coils originating from the conventional stator during nominal operation. To compute these losses, a 2D finite element analysis was conducted and Maxwell’s equations written in the H-formulation were solved considering the nonlinear material properties of the conductor materials. The modeled tapes are made of multiple MgB2 filaments embedded in a Ni matrix and soldered to a high purity copper strip and insulated with Dacron braid. Three geometrical models of single tape cross sections of decreasing complexity were studied: (1) the first model reproduced closely the actual cross section obtained from tape micrographs. (2) The second model was obtained from the computed elasto-plastic deformation of a round Ni wire. (3) The third model was based on a simplified cross section with the superconducting filaments bundled in a single elliptical bulky structure. The last geometry allowed the validation of the modeling technique by comparing numerical losses with results from well-established analytical expressions. Additionally, the following cases of filament transpositions of the multi-filamentary tape were studied: no transposition, partial and full transposition; thereby improving understanding of the relevance of the tape fabrication process on the magnitude of the determination of ac losses. Finally, choosing the right level of geometrical detail, the following operational regimes of the machine and its impact on individual superconducting tape losses in the rotor were studied: bias-dc current, ramping current under ramping background field and magnetic flux ripples under dc background current and field.

Estimation of hysteretic losses for MgB2 tapes under the operating conditions of a generator

International Nuclear Information System (INIS)

Vargas-Llanos, Carlos Roberto; Zermeño, Víctor M R; Grilli, Francesco; Sanz, Santiago; Trillaud, Frederic

2016-01-01

Hysteretic losses in the MgB 2 wound superconducting coils of a 550 kW synchronous hybrid scaled generator were estimated as part of the European project SUPRAPOWER led by the Spanish Fundación Tecnalia Research and Innovation. Particular interest was given to the losses caused by the magnetic flux ripples in the rotor coils originating from the conventional stator during nominal operation. To compute these losses, a 2D finite element analysis was conducted and Maxwell’s equations written in the H-formulation were solved considering the nonlinear material properties of the conductor materials. The modeled tapes are made of multiple MgB 2 filaments embedded in a Ni matrix and soldered to a high purity copper strip and insulated with Dacron braid. Three geometrical models of single tape cross sections of decreasing complexity were studied: (1) the first model reproduced closely the actual cross section obtained from tape micrographs. (2) The second model was obtained from the computed elasto-plastic deformation of a round Ni wire. (3) The third model was based on a simplified cross section with the superconducting filaments bundled in a single elliptical bulky structure. The last geometry allowed the validation of the modeling technique by comparing numerical losses with results from well-established analytical expressions. Additionally, the following cases of filament transpositions of the multi-filamentary tape were studied: no transposition, partial and full transposition; thereby improving understanding of the relevance of the tape fabrication process on the magnitude of the determination of ac losses. Finally, choosing the right level of geometrical detail, the following operational regimes of the machine and its impact on individual superconducting tape losses in the rotor were studied: bias-dc current, ramping current under ramping background field and magnetic flux ripples under dc background current and field. (paper)

Calcium constrains plant control over forest ecosystem nitrogen cycling.

Science.gov (United States)

Groffman, Peter M; Fisk, Melany C

2011-11-01

Forest ecosystem nitrogen (N) cycling is a critical controller of the ability of forests to prevent the movement of reactive N to receiving waters and the atmosphere and to sequester elevated levels of atmospheric carbon dioxide (CO2). Here we show that calcium (Ca) constrains the ability of northern hardwood forest trees to control the availability and loss of nitrogen. We evaluated soil N-cycling response to Ca additions in the presence and absence of plants and observed that when plants were present, Ca additions "tightened" the ecosystem N cycle, with decreases in inorganic N levels, potential net N mineralization rates, microbial biomass N content, and denitrification potential. In the absence of plants, Ca additions induced marked increases in nitrification (the key process controlling ecosystem N losses) and inorganic N levels. The observed "tightening" of the N cycle when Ca was added in the presence of plants suggests that the capacity of forests to absorb elevated levels of atmospheric N and CO2 is fundamentally constrained by base cations, which have been depleted in many areas of the globe by acid rain and forest harvesting.

Assessing the Impact of Landscape Development on Ecosystem Services Value in Tropical Watershed

International Nuclear Information System (INIS)

Foo, Y S; Hashim, M

2014-01-01

As development increases with demand, more forest lands are replaced with cropland, commercial plantation, and infrastructures for being able to accommodate the excessive growth in world's population. Environments were destroyed without considering their values in sustaining life on Earth.This phenomenon is still an ongoing scenario in most of the developing countries in the tropical region including Malaysia. Such unrestricted conversion may cause food or water crisis along with irreparable consequences to local and regional climate as the natural ecosystem is not only the main resources generator but also the climate stabilizer. Contrary to this, a study was conducted in Pahang Watershed, the largest watershed in Peninsular Malaysia with forest as the dominant land cover, to investigate the effect of landscape development on the ecosystem in terms of the erosion and ecosystem service value. Results of soil loss based on USLE indicated a direct relationship between development and total soil loss where total annual soil loss in year 2005 and 2010 showed a significant increase compare to year 2000. Meanwhile, developed and agricultural lands were discovered to be the main contributor whereas forest land produce the least soil loss (<10ton/ ha/yr). Apart from this, this study also reports a degrading trend in the overall ecological service value and goods (ESVG). Although oil palm had become the main commercial plantation in current years, the commercial profit brought by oil palm still insufficient to cover losses referring to overall estimated ESVG due to the forest clearance and soil degradation. In addition, for a destroyed ecosystem to be equilibrium again requires years. Therefore, ESVG of the tropical forest are expected to increase continuously in future which mean that the roles of the forest in conserving the environment stabilization and sustainability of life are getting more critical

Lake and wetland ecosystem services measuring water storage and local climate regulation

Science.gov (United States)

Wong, Christina P.; Jiang, Bo; Bohn, Theodore J.; Lee, Kai N.; Lettenmaier, Dennis P.; Ma, Dongchun; Ouyang, Zhiyun

2017-04-01

Developing interdisciplinary methods to measure ecosystem services is a scientific priority, however, progress remains slow in part because we lack ecological production functions (EPFs) to quantitatively link ecohydrological processes to human benefits. In this study, we tested a new approach, combining a process-based model with regression models, to create EPFs to evaluate water storage and local climate regulation from a green infrastructure project on the Yongding River in Beijing, China. Seven artificial lakes and wetlands were established to improve local water storage and human comfort; evapotranspiration (ET) regulates both services. Managers want to minimize the trade-off between water losses and cooling to sustain water supplies while lowering the heat index (HI) to improve human comfort. We selected human benefit indicators using water storage targets and Beijing's HI, and the Variable Infiltration Capacity model to determine the change in ET from the new ecosystems. We created EPFs to quantify the ecosystem services as marginal values [Δfinal ecosystem service/Δecohydrological process]: (1) Δwater loss (lake evaporation/volume)/Δdepth and (2) Δsummer HI/ΔET. We estimate the new ecosystems increased local ET by 0.7 mm/d (20.3 W/m2) on the Yongding River. However, ET rates are causing water storage shortfalls while producing no improvements in human comfort. The shallow lakes/wetlands are vulnerable to drying when inflow rates fluctuate, low depths lead to higher evaporative losses, causing water storage shortfalls with minimal cooling effects. We recommend managers make the lakes deeper to increase water storage, and plant shade trees to improve human comfort in the parks.

Changes in biodiversity and functioning of reef fish assemblages following coral bleaching and coral loss

KAUST Repository

Pratchett, M.S.; Hoey, A.S.; Wilson, S.K.; Messmer, V.; Graham, N.A.J.

2011-01-01

Coral reef ecosystems are increasingly subject to severe, large-scale disturbances caused by climate change (e.g., coral bleaching) and other more direct anthropogenic impacts. Many of these disturbances cause coral loss and corresponding changes in habitat structure, which has further important effects on abundance and diversity of coral reef fishes. Declines in the abundance and diversity of coral reef fishes are of considerable concern, given the potential loss of ecosystem function. This study explored the effects of coral loss, recorded in studies conducted throughout the world, on the diversity of fishes and also on individual responses of fishes within different functional groups. Extensive (>60%) coral loss almost invariably led to declines in fish diversity. Moreover, most fishes declined in abundance following acute disturbances that caused >10% declines in local coral cover. Response diversity, which is considered critical in maintaining ecosystem function and promoting resilience, was very low for corallivores, but was much higher for herbivores, omnivores and carnivores. Sustained and ongoing climate change thus poses a significant threat to coral reef ecosystems and diversity hotspots are no less susceptible to projected changes in diversity and function.

Changes in biodiversity and functioning of reef fish assemblages following coral bleaching and coral loss

KAUST Repository

Pratchett, M.S.

2011-08-12

Coral reef ecosystems are increasingly subject to severe, large-scale disturbances caused by climate change (e.g., coral bleaching) and other more direct anthropogenic impacts. Many of these disturbances cause coral loss and corresponding changes in habitat structure, which has further important effects on abundance and diversity of coral reef fishes. Declines in the abundance and diversity of coral reef fishes are of considerable concern, given the potential loss of ecosystem function. This study explored the effects of coral loss, recorded in studies conducted throughout the world, on the diversity of fishes and also on individual responses of fishes within different functional groups. Extensive (>60%) coral loss almost invariably led to declines in fish diversity. Moreover, most fishes declined in abundance following acute disturbances that caused >10% declines in local coral cover. Response diversity, which is considered critical in maintaining ecosystem function and promoting resilience, was very low for corallivores, but was much higher for herbivores, omnivores and carnivores. Sustained and ongoing climate change thus poses a significant threat to coral reef ecosystems and diversity hotspots are no less susceptible to projected changes in diversity and function.

Modeling dynamics of biological and chemical components of aquatic ecosystems

International Nuclear Information System (INIS)

Lassiter, R.R.

1975-05-01

To provide capability to model aquatic ecosystems or their subsystems as needed for particular research goals, a modeling strategy was developed. Submodels of several processes common to aquatic ecosystems were developed or adapted from previously existing ones. Included are submodels for photosynthesis as a function of light and depth, biological growth rates as a function of temperature, dynamic chemical equilibrium, feeding and growth, and various types of losses to biological populations. These submodels may be used as modules in the construction of models of subsystems or ecosystems. A preliminary model for the nitrogen cycle subsystem was developed using the modeling strategy and applicable submodels. (U.S.)

Hurricanes Katrina and Rita and the Coastal Louisiana Ecosystem Restoration

National Research Council Canada - National Science Library

Zinn, Jeffrey

2005-01-01

... for a $1.1 billion multiyear program to construct five projects that would help to restore portions of the coastal Louisiana ecosystem by slowing the rate of wetland loss and restoring some wetlands...

Modelling the Frequency of Operational Risk Losses under the Basel II Capital Accord: A Comparative study of Poisson and Negative Binomial Distributions

OpenAIRE

Silver, Toni O.

2013-01-01

2013 dissertation for MSc in Finance and Risk Management. Selected by academic staff as a good example of a masters level dissertation. \\ud \\ud This study investigated the two major methods of modelling the frequency of\\ud operational losses under the BCBS Accord of 1998 known as Basel II Capital\\ud Accord. It compared the Poisson method of modelling the frequency of\\ud losses to that of the Negative Binomial. The frequency of operational losses\\ud was investigated using a cross section of se...

Citation patterns of a controversial and high-impact paper: Worm et al. (2006 "Impacts of biodiversity loss on ocean ecosystem services".

Directory of Open Access Journals (Sweden)

Trevor A Branch

Full Text Available Citation patterns were examined for Worm et al. 2006 (Science 314:787-790, a high-impact paper that focused on relationships between marine biodiversity and ecosystem services. This paper sparked much controversy through its projection, highlighted in the press release, that all marine fisheries would be collapsed by 2048. Analysis of 664 citing papers revealed that only a small percentage (11% referred to the 2048 projection, while 39% referred to fisheries collapse in general, and 40% to biodiversity and ecosystem services. The 2048 projection was mentioned more often in papers published soon after the original paper, in low-impact journals, and in journals outside of fields that would be expected to focus on biodiversity. Citing papers also mentioned the 2048 projection more often if they had few authors (28% of single-author papers vs. 2% of papers with 10 or more authors. These factors suggest that the more knowledgeable the authors of citing papers were about the controversy over the 2048 projection, the less likely they were to refer to it. A noteworthy finding was that if the original authors were also involved in the citing papers, they rarely (1 of 55 papers, 2% mentioned the 2048 projection. Thus the original authors have emphasized the broader concerns about biodiversity loss, rather than the 2048 projection, as the key result of their study.

Citation patterns of a controversial and high-impact paper: Worm et al. (2006) "Impacts of biodiversity loss on ocean ecosystem services".

Science.gov (United States)

Branch, Trevor A

2013-01-01

Citation patterns were examined for Worm et al. 2006 (Science 314:787-790), a high-impact paper that focused on relationships between marine biodiversity and ecosystem services. This paper sparked much controversy through its projection, highlighted in the press release, that all marine fisheries would be collapsed by 2048. Analysis of 664 citing papers revealed that only a small percentage (11%) referred to the 2048 projection, while 39% referred to fisheries collapse in general, and 40% to biodiversity and ecosystem services. The 2048 projection was mentioned more often in papers published soon after the original paper, in low-impact journals, and in journals outside of fields that would be expected to focus on biodiversity. Citing papers also mentioned the 2048 projection more often if they had few authors (28% of single-author papers vs. 2% of papers with 10 or more authors). These factors suggest that the more knowledgeable the authors of citing papers were about the controversy over the 2048 projection, the less likely they were to refer to it. A noteworthy finding was that if the original authors were also involved in the citing papers, they rarely (1 of 55 papers, 2%) mentioned the 2048 projection. Thus the original authors have emphasized the broader concerns about biodiversity loss, rather than the 2048 projection, as the key result of their study.

Deep-Sea Mining With No Net Loss of Biodiversity—An Impossible Aim

Directory of Open Access Journals (Sweden)

Holly J. Niner

2018-03-01

Full Text Available Deep-sea mining is likely to result in biodiversity loss, and the significance of this to ecosystem function is not known. “Out of kind” biodiversity offsets substituting one ecosystem type (e.g., coral reefs for another (e.g., abyssal nodule fields have been proposed to compensate for such loss. Here we consider a goal of no net loss (NNL of biodiversity and explore the challenges of applying this aim to deep seabed mining, based on the associated mitigation hierarchy (avoid, minimize, remediate. We conclude that the industry cannot at present deliver an outcome of NNL. This results from the vulnerable nature of deep-sea environments to mining impacts, currently limited technological capacity to minimize harm, significant gaps in ecological knowledge, and uncertainties of recovery potential of deep-sea ecosystems. Avoidance and minimization of impacts are therefore the only presently viable means of reducing biodiversity losses from seabed mining. Because of these constraints, when and if deep-sea mining proceeds, it must be approached in a precautionary and step-wise manner to integrate new and developing knowledge. Each step should be subject to explicit environmental management goals, monitoring protocols, and binding standards to avoid serious environmental harm and minimize loss of biodiversity. “Out of kind” measures, an option for compensation currently proposed, cannot replicate biodiversity and ecosystem services lost through mining of the deep seabed and thus cannot be considered true offsets. The ecosystem functions provided by deep-sea biodiversity contribute to a wide range of provisioning services (e.g., the exploitation of fish, energy, pharmaceuticals, and cosmetics, play an essential role in regulatory services (e.g., carbon sequestration and are important culturally. The level of “acceptable” biodiversity loss in the deep sea requires public, transparent, and well-informed consideration, as well as wide agreement

Influence of curve magnitude and other variables on operative time, blood loss and transfusion requirements in adolescent idiopathic scoliosis.

LENUS (Irish Health Repository)

Nugent, M

2015-05-03

Posterior spinal instrumentation and fusion for correction of adolescent idiopathic scoliosis (AIS) typically requires lengthy operating time and may be associated with significant blood loss and subsequent transfusion. This study aimed to identify factors predictive of duration of surgery, intraoperative blood loss and transfusion requirements in an Irish AIS cohort.

Using grizzly bears to assess harvest-ecosystem tradeoffs in salmon fisheries.

Science.gov (United States)

Levi, Taal; Darimont, Chris T; Macduffee, Misty; Mangel, Marc; Paquet, Paul; Wilmers, Christopher C

2012-01-01

Implementation of ecosystem-based fisheries management (EBFM) requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon provide to terrestrial and aquatic food webs. We used grizzly bears, vectors of salmon nutrients and animals with densities strongly coupled to salmon abundance, as surrogates for "salmon ecosystem" function. Combining salmon biomass and stock-recruitment data with stable isotope analysis, we assess potential tradeoffs between fishery yields and bear population densities for six sockeye salmon stocks in Bristol Bay, Alaska, and British Columbia (BC), Canada. For the coastal stocks, we find that both bear densities and fishery yields would increase substantially if ecosystem allocations of salmon increase from currently applied lower to upper goals and beyond. This aligning of benefits comes at a potential cost, however, with the possibility of forgoing harvests in low productivity years. In contrast, we detect acute tradeoffs between bear densities and fishery yields in interior stocks within the Fraser River, BC, where biomass from other salmon species is low. There, increasing salmon allocations to ecosystems would benefit threatened bear populations at the cost of reduced long-term yields. To resolve this conflict, we propose an EBFM goal that values fisheries and bears (and by extension, the ecosystem) equally. At such targets, ecosystem benefits are unexpectedly large compared with losses in fishery yields. To explore other management options, we generate tradeoff curves that provide stock-specific accounting of the expected loss to fishers and gain to bears as more salmon escape the fishery. Our approach, modified to suit multiple scenarios, provides a generalizable method

Using grizzly bears to assess harvest-ecosystem tradeoffs in salmon fisheries.

Directory of Open Access Journals (Sweden)

Taal Levi

Full Text Available Implementation of ecosystem-based fisheries management (EBFM requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon provide to terrestrial and aquatic food webs. We used grizzly bears, vectors of salmon nutrients and animals with densities strongly coupled to salmon abundance, as surrogates for "salmon ecosystem" function. Combining salmon biomass and stock-recruitment data with stable isotope analysis, we assess potential tradeoffs between fishery yields and bear population densities for six sockeye salmon stocks in Bristol Bay, Alaska, and British Columbia (BC, Canada. For the coastal stocks, we find that both bear densities and fishery yields would increase substantially if ecosystem allocations of salmon increase from currently applied lower to upper goals and beyond. This aligning of benefits comes at a potential cost, however, with the possibility of forgoing harvests in low productivity years. In contrast, we detect acute tradeoffs between bear densities and fishery yields in interior stocks within the Fraser River, BC, where biomass from other salmon species is low. There, increasing salmon allocations to ecosystems would benefit threatened bear populations at the cost of reduced long-term yields. To resolve this conflict, we propose an EBFM goal that values fisheries and bears (and by extension, the ecosystem equally. At such targets, ecosystem benefits are unexpectedly large compared with losses in fishery yields. To explore other management options, we generate tradeoff curves that provide stock-specific accounting of the expected loss to fishers and gain to bears as more salmon escape the fishery. Our approach, modified to suit multiple scenarios, provides a

Effects of biodiversity on ecosystem functioning: a consensus of current knowledge

Science.gov (United States)

Hooper, D.U.; Chapin, F. S.; Ewel, J.J.; Hector, A.; Inchausti, P.; Lavorel, S.; Lawton, J.H.; Lodge, D.M.; Loreau, M.; Naeem, S.; Schmid, B.; SetSlS, H.; Symstad, A.J.; Vandermeer, J.; Wardle, D.A.

2005-01-01

Humans are altering the composition of biological communities through a variety of activities that increase rates of species invasions and species extinctions, at all scales, from local to global. These changes in components of the Earth's biodiversity cause concern for ethical and aesthetic reasons, but they also have a strong potential to alter ecosystem properties and the goods and services they provide to humanity. Ecological experiments, observations, and theoretical developments show that ecosystem properties depend greatly on biodiversity in terms of the functional characteristics of organisms present in the ecosystem and the distribution and abundance of those organisms over space and time. Species effects act in concert with the effects of climate, resource availability, and disturbance regimes in influencing ecosystem properties. Human activities can modify all of the above factors; here we focus on modification of these biotic controls.The scientific community has come to a broad consensus on many aspects of the relationship between biodiversity and ecosystem functioning, including many points relevant to management of ecosystems. Further progress will require integration of knowledge about biotic and abiotic controls on ecosystem properties, how ecological communities are structured, and the forces driving species extinctions and invasions. To strengthen links to policy and management, we also need to integrate our ecological knowledge with understanding of the social and economic constraints of potential management practices. Understanding this complexity, while taking strong steps to minimize current losses of species, is necessary for responsible management of Earth's ecosystems and the diverse biota they contain.Based on our review of the scientific literature, we are certain of the following conclusions:1) Species' functional characteristics strongly influence ecosystem properties. Functional characteristics operate in a variety of contexts

Loss Minimizing Operation of Doubly Fed Induction Generator Based Wind Generation Systems Considering Reactive Power Provision

DEFF Research Database (Denmark)

Baohua, Zhang; Hu, Weihao; Chen, Zhe

2014-01-01

The paper deals with control techniques for minimizing the operating loss of doubly fed induction generator based wind generation systems when providing reactive power. The proposed method achieves its goal through controlling the rotor side q-axis current in the synchronous reference frame...

Madagascar’s Mangroves: Quantifying Nation-Wide and Ecosystem Specific Dynamics, and Detailed Contemporary Mapping of Distinct Ecosystems

Directory of Open Access Journals (Sweden)

Trevor G. Jones

2016-01-01

Full Text Available Mangrove ecosystems help mitigate climate change, are highly biodiverse, and provide critical goods and services to coastal communities. Despite their importance, anthropogenic activities are rapidly degrading and deforesting mangroves world-wide. Madagascar contains 2% of the world’s mangroves, many of which have undergone or are starting to exhibit signs of widespread degradation and deforestation. Remotely sensed data can be used to quantify mangrove loss and characterize remaining distributions, providing detailed, accurate, timely and updateable information. We use USGS maps produced from Landsat data to calculate nation-wide dynamics for Madagascar’s mangroves from 1990 to 2010, and examine change more closely by partitioning the national distribution in to primary (i.e., >1000 ha ecosystems; with focus on four Areas of Interest (AOIs: Ambaro-Ambanja Bays (AAB, Mahajamba Bay (MHJ, Tsiribihina Manombolo Delta (TMD and Bay des Assassins (BdA. Results indicate a nation–wide net-loss of 21% (i.e., 57,359 ha from 1990 to 2010, with dynamics varying considerably among primary mangrove ecosystems. Given the limitations of national-level maps for certain localized applications (e.g., carbon stock inventories, building on two previous studies for AAB and MHJ, we employ Landsat data to produce detailed, contemporary mangrove maps for TMD and BdA. These contemporary, AOI-specific maps provide improved detail and accuracy over the USGS national-level maps, and are being applied to conservation and restoration initiatives through the Blue Ventures’ Blue Forests programme and WWF Madagascar West Indian Ocean Programme Office’s work in the region.

A Practical Decision-Analysis Process for Forest Ecosystem Management

Science.gov (United States)

H. Michael Rauscher; F. Thomas Lloyd; David L. Loftis; Mark J. Twery

2000-01-01

Many authors have pointed out the need to firm up the 'fuzzy' ecosystem management paradigm and develop operationally practical processes to allow forest managers to accommodate more effectively the continuing rapid change in societal perspectives and goals. There are three spatial scales where clear, precise, practical ecosystem management processes are...

Ecosystem-based management and the wealth of ecosystems

OpenAIRE

Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K.; Fenichel, Eli P.

2017-01-01

Ecosystems store vast quantities of wealth, but difficulties measuring wealth held in ecosystems prevent its inclusion in accounting systems. Ecosystem-based management endeavors to manage ecosystems holistically. However, ecosystem-based management lacks headline indicators to evaluate performance. We unify the inclusive wealth and ecosystem-based management paradigms, allowing apples-to-apples comparisons between the wealth of the ecosystem and other forms of wealth, while providing a headl...

Dissolved carbon leaching from soil is a crucial component of the net ecosystem carbon balance

DEFF Research Database (Denmark)

Kindler, Reimo; Siemens, Jan; Kaiser, Klaus

2011-01-01

ecosystem exchange (NEE) plus carbon inputs with fertilization minus carbon removal with harvest. Carbon leaching increased the net losses from cropland soils by 24–105% (median: 25%). For the majority of forest sites, leaching hardly affected actual net ecosystem carbon balances because of the small...... solubility of CO2 in acidic forest soil solutions and large NEE. Leaching of CH4 proved to be insignificant compared with other fluxes of carbon. Overall, our results show that leaching losses are particularly important for the carbon balance of agricultural systems....

Enhanced Store-Operated Calcium Entry Leads to Striatal Synaptic Loss in a Huntington's Disease Mouse Model.

Science.gov (United States)

Wu, Jun; Ryskamp, Daniel A; Liang, Xia; Egorova, Polina; Zakharova, Olga; Hung, Gene; Bezprozvanny, Ilya

2016-01-06

In Huntington's disease (HD), mutant Huntingtin (mHtt) protein causes striatal neuron dysfunction, synaptic loss, and eventual neurodegeneration. To understand the mechanisms responsible for synaptic loss in HD, we developed a corticostriatal coculture model that features age-dependent dendritic spine loss in striatal medium spiny neurons (MSNs) from YAC128 transgenic HD mice. Age-dependent spine loss was also observed in vivo in YAC128 MSNs. To understand the causes of spine loss in YAC128 MSNs, we performed a series of mechanistic studies. We previously discovered that mHtt protein binds to type 1 inositol (1,4,5)-trisphosphate receptor (InsP3R1) and increases its sensitivity to activation by InsP3. We now report that the resulting increase in steady-state InsP3R1 activity reduces endoplasmic reticulum (ER) Ca(2+) levels. Depletion of ER Ca(2+) leads to overactivation of the neuronal store-operated Ca(2+) entry (nSOC) pathway in YAC128 MSN spines. The synaptic nSOC pathway is controlled by the ER resident protein STIM2. We discovered that STIM2 expression is elevated in aged YAC128 striatal cultures and in YAC128 mouse striatum. Knock-down of InsP3R1 expression by antisense oligonucleotides or knock-down or knock-out of STIM2 resulted in normalization of nSOC and rescue of spine loss in YAC128 MSNs. The selective nSOC inhibitor EVP4593 was identified in our previous studies. We now demonstrate that EVP4593 reduces synaptic nSOC and rescues spine loss in YAC128 MSNs. Intraventricular delivery of EVP4593 in YAC128 mice rescued age-dependent striatal spine loss in vivo. Our results suggest EVP4593 and other inhibitors of the STIM2-dependent nSOC pathway as promising leads for HD therapeutic development. In Huntington's disease (HD) mutant Huntingtin (mHtt) causes early corticostriatal synaptic dysfunction and eventual neurodegeneration of medium spine neurons (MSNs) through poorly understood mechanisms. We report here that corticostriatal cocultures prepared from

Variance as a Leading Indicator of Regime Shift in Ecosystem Services

Directory of Open Access Journals (Sweden)

William A. Brock

2006-12-01

Full Text Available Many environmental conflicts involve pollutants such as greenhouse gas emissions that are dispersed through space and cause losses of ecosystem services. As pollutant emissions rise in one place, a spatial cascade of declining ecosystem services can spread across a larger landscape because of the dispersion of the pollutant. This paper considers the problem of anticipating such spatial regime shifts by monitoring time series of the pollutant or associated ecosystem services. Using such data, it is possible to construct indicators that rise sharply in advance of regime shifts. Specifically, the maximum eigenvalue of the variance-covariance matrix of the multivariate time series of pollutants and ecosystem services rises prior to the regime shift. No specific knowledge of the mechanisms underlying the regime shift is needed to construct the indicator. Such leading indicators of regime shifts could provide useful signals to management agencies or to investors in ecosystem service markets.

Global Human Footprint on the Linkage between Biodiversity and Ecosystem Functioning in Reef Fishes

Science.gov (United States)

Mora, Camilo; Aburto-Oropeza, Octavio; Ayala Bocos, Arturo; Ayotte, Paula M.; Banks, Stuart; Bauman, Andrew G.; Beger, Maria; Bessudo, Sandra; Booth, David J.; Brokovich, Eran; Brooks, Andrew; Chabanet, Pascale; Cinner, Joshua E.; Cortés, Jorge; Cruz-Motta, Juan J.; Cupul Magaña, Amilcar; DeMartini, Edward E.; Edgar, Graham J.; Feary, David A.; Ferse, Sebastian C. A.; Friedlander, Alan M.; Gaston, Kevin J.; Gough, Charlotte; Graham, Nicholas A. J.; Green, Alison; Guzman, Hector; Hardt, Marah; Kulbicki, Michel; Letourneur, Yves; López Pérez, Andres; Loreau, Michel; Loya, Yossi; Martinez, Camilo; Mascareñas-Osorio, Ismael; Morove, Tau; Nadon, Marc-Olivier; Nakamura, Yohei; Paredes, Gustavo; Polunin, Nicholas V. C.; Pratchett, Morgan S.; Reyes Bonilla, Héctor; Rivera, Fernando; Sala, Enric; Sandin, Stuart A.; Soler, German; Stuart-Smith, Rick; Tessier, Emmanuel; Tittensor, Derek P.; Tupper, Mark; Usseglio, Paolo; Vigliola, Laurent; Wantiez, Laurent; Williams, Ivor; Wilson, Shaun K.; Zapata, Fernando A.

2011-01-01

Difficulties in scaling up theoretical and experimental results have raised controversy over the consequences of biodiversity loss for the functioning of natural ecosystems. Using a global survey of reef fish assemblages, we show that in contrast to previous theoretical and experimental studies, ecosystem functioning (as measured by standing biomass) scales in a non-saturating manner with biodiversity (as measured by species and functional richness) in this ecosystem. Our field study also shows a significant and negative interaction between human population density and biodiversity on ecosystem functioning (i.e., for the same human density there were larger reductions in standing biomass at more diverse reefs). Human effects were found to be related to fishing, coastal development, and land use stressors, and currently affect over 75% of the world's coral reefs. Our results indicate that the consequences of biodiversity loss in coral reefs have been considerably underestimated based on existing knowledge and that reef fish assemblages, particularly the most diverse, are greatly vulnerable to the expansion and intensity of anthropogenic stressors in coastal areas. PMID:21483714

Use of environmental functions to communicate the values of a mangrove ecosystem under different management regimes

NARCIS (Netherlands)

Gilbert, A.J.; Janssen, R.

1998-01-01

Mangroves are part of rich ecosystems providing a variety of environmental goods and services. Underestimation of their value and of the impacts of human activities is a major factor contributing to the widespread loss and degradation of ecosystems. Economists frequently receive the blame for such

Anthropogenic Drivers of Ecosystem Change: an Overview

Directory of Open Access Journals (Sweden)

Gerald C. Nelson

2006-12-01

Full Text Available This paper provides an overview of what the Millennium Ecosystem Assessment (MA calls "indirect and direct drivers" of change in ecosystem services at a global level. The MA definition of a driver is any natural or human-induced factor that directly or indirectly causes a change in an ecosystem. A direct driver unequivocally influences ecosystem processes. An indirect driver operates more diffusely by altering one or more direct drivers. Global driving forces are categorized as demographic, economic, sociopolitical, cultural and religious, scientific and technological, and physical and biological. Drivers in all categories other than physical and biological are considered indirect. Important direct drivers include changes in climate, plant nutrient use, land conversion, and diseases and invasive species. This paper does not discuss natural drivers such as climate variability, extreme weather events, or volcanic eruptions.

Managing Multiple Catchment Demands for Sustainable Water Use and Ecosystem Service Provision

Directory of Open Access Journals (Sweden)

Kathleen C. Stosch

2017-09-01

Full Text Available Ensuring water, food and energy security for a growing world population represents a 21st century catchment management challenge. Failure to recognise the complexity of interactions across ecosystem service provision can risk the loss of other key environmental and socioeconomic benefits from the natural capital of catchment systems. In particular, the ability of soil and water to meet human needs is undermined by uncertainties around climate change effects, ecosystem service interactions and conflicting stakeholder interests across catchments. This critical review draws from an extensive literature to discuss the benefits and challenges of utilising an ecosystem service approach for integrated catchment management (ICM. State-of-the-art research on ecosystem service assessment, mapping and participatory approaches is evaluated and a roadmap of the key short- and longer-term research needs for maximising landscape-scale ecosystem service provision from catchments is proposed.

Allowing variance may enlarge the safe operating space for exploited ecosystems

NARCIS (Netherlands)

Carpenter, S.R.; Brock, W.A.; Folke, Carl; Nes, Van E.H.; Scheffer, Marten; Polasky, Stephen

2015-01-01

Variable flows of food, water, or other ecosystem services complicate planning. Management strategies that decrease variability and increase predictabilitymay therefore be preferred. However, actions to decrease variance over short timescales (2-4 y), when applied continuously,may lead to

Precipitation as driver of carbon fluxes in 11 African ecosystems

NARCIS (Netherlands)

Merbold, L.; Ardo, J.; Arneth, A.; Scholes, R.J.; Nouvellon, Y.; Grandcourt, de A.; Archibald, S.; Bonnefonds, J.M.; Boulain, N.; Bruemmer, C.; Brueggemann, N.; Cappelaere, B.; Ceschia, E.; El-Khidir, H.A.M.; El-Tahir, B.A.; Falk, U.; Lloyd, J.; Kergoat, L.; Dantec, Le V.; Mougin, E.; Muchinda, M.; Mukelabai, M.M.; Ramier, D.; Roupsard, O.; Timouk, F.; Veenendaal, E.M.; Kutsch, W.L.

2009-01-01

This study reports carbon and water fluxes between the land surface and atmosphere in eleven different ecosystems types in Sub-Saharan Africa, as measured using eddy covariance (EC) technology in the first two years of the CarboAfrica network operation. The ecosystems for which data were available

Attribution of irreversible loss to anthropogenic climate change

Science.gov (United States)

Huggel, Christian; Bresch, David; Hansen, Gerrit; James, Rachel; Mechler, Reinhard; Stone, Dáithí; Wallimann-Helmer, Ivo

2016-04-01

of land area due to coastal and hillslope erosion and sea level change; loss of plant and animal species, loss of ecosystems and biodiversity; loss of human lives, homelands, and cultural identity. Attribution to anthropogenic climate change is analyzed based on recent progress following from the IPCC AR5. Generally, high confidence in attributing irreversible loss to anthropogenic climate change is found in physical systems and more specifically in cryosphere environments, both in mountain and polar regions. Detected loss in terrestrial ecosystems has typically low confidence in attribution whereas loss in some ocean ecosystems (corals) has high confidence. Impacts in human systems that may be classified as irreversible loss are of low confidence in terms of attribution except for the Arctic where higher confidence for a relation with anthropogenic emissions was found. Our analysis suggests that scientific progress in detection and attribution is now at a level that would likely allow policy, or courts, to define mechanisms, or take decisions, as related to irreversible loss in many cryosphere systems. On the other hand, policy may need to consider that at least in the near future it will be difficult to establish clear tracks between irreversible loss in most human systems and anthropogenic climate change, a domain, which however is at the forefront of discussions. We end our discussion with setting out ideas for further clarification of different categories of irreversible loss, including in human systems, and the role of attribution in any policy or legal mechanism in order to help in the development of just and sensible solutions.

How stakeholders frame dam removal: The role of current and anticipated future ecosystem service use

Science.gov (United States)

Reilly, Kate; Adamowski, Jan

2016-04-01

Many river restoration projects, including dam removal, are controversial and can trigger conflicts between stakeholders who are for and against the proposed project. The study of environmental conflicts suggests that differences in how stakeholders 'frame', or make sense of a situation based on their prior knowledge and experiences, can perpetuate conflicts. Understanding different stakeholders' frames, particularly how they converge, can form the basis of successful conflict resolution. In the case of dam removals, it is often assumed that emphasising increased provision of ecosystem services can be a point of convergence between those advocating for ecological restoration and those opposed to removal because of negative human impacts. However, how exactly stakeholders frame a contentious proposed dam removal and how those frames relate to ecosystem services has been little studied. Here we used the case of a potential dam removal in New Brunswick to investigate how people frame the issue and how that relates to their current and anticipated future use of ecosystem services. Based on in-depth interviews with 30 stakeholders in the area, including both people for and against dam removal, we found that both groups currently used ecosystem services and were in favour of ecosystem protection. However, they differed in how they framed the issue of the potential dam removal. The group against dam removal framed the issue as one of loss and risk - they thought that any potential benefits to the ecosystem would be outweighed by the high risk of negative social impacts caused by a loss of access to ecosystem services, such as recreation and aesthetic enjoyment. By contrast, the group in favour of the dam framed the issue as one of opportunity and justice. They thought that following a short transition period, all stakeholders would benefit from the restored river, particularly from a restored salmon fishery, improved aesthetic appeal and the long-term sustainability of an

Surface runoff and phosphorus (P) loss from bamboo (Phyllostachys ...

African Journals Online (AJOL)

Jane

2011-08-24

Aug 24, 2011 ... Key words: Phyllostachys pubescens, ecosystem, surface runoff, phosphorus (P) loss. .... targets and corresponding nutrient demand, nutrient balance and nutrient use .... rainfall, rainfall intensity as well as solar radiation and.

Ecosystemic approaches to land degradation

Energy Technology Data Exchange (ETDEWEB)

Puigdefabregas, J.; Barrio, G. del; Hill, J.

2009-07-01

Land degradation is recognized as the main outcome of desertification. However available procedures for its assessment are still unsatisfactory because are often too costly for surveying large areas and rely on specific components of the degradation process without being able to integrate them in a unique process. One of the objectives of De Survey project is designing and implementing operational procedures for desertification surveillance, including land degradation. A strategic report was compiled and reproduced here for selecting the most appropriate approaches to the project conditions. The report focuses on using attributes of ecosystem maturity as a natural way to integrate the different drivers of land degradation in simple indices. The review surveys different families of attributes concerned with water and energy fluxes through the ecosystem, its capacity to sustain biomass and net primary productivity, and its capacity to structure the space. Finally, some conclusions are presented about the choice criteria of the different approaches in the framne of operational applications. (Author) 20 refs.

Ecosystemic approaches to land degradation

International Nuclear Information System (INIS)

Puigdefabregas, J.; Barrio, G. del; Hill, J.

2009-01-01

Land degradation is recognized as the main outcome of desertification. However available procedures for its assessment are still unsatisfactory because are often too costly for surveying large areas and rely on specific components of the degradation process without being able to integrate them in a unique process. One of the objectives of De Survey project is designing and implementing operational procedures for desertification surveillance, including land degradation. A strategic report was compiled and reproduced here for selecting the most appropriate approaches to the project conditions. The report focuses on using attributes of ecosystem maturity as a natural way to integrate the different drivers of land degradation in simple indices. The review surveys different families of attributes concerned with water and energy fluxes through the ecosystem, its capacity to sustain biomass and net primary productivity, and its capacity to structure the space. Finally, some conclusions are presented about the choice criteria of the different approaches in the framne of operational applications. (Author) 20 refs.

TERRECO: A Flux-Based Approach to Understanding Landscape Change, Potentials of Resilience and Sustainability in Ecosystem Services

Science.gov (United States)

Tenhunen, J. D.; Kang, S.

2011-12-01

The Millenium Assessment has provided a broad perspective on the ways and degree to which global change has stressed ecosystems and their potential to deliver goods and services to mankind. Management of natural resources at regional scale requires a clear understanding of the ways that ongoing human activities modify or create new system stressors, leading to net gains or losses in ecosystem services. Ever since information from the International Biological Program (IBP) was summarized in the 1960s, we know that ecosystem stress response, recovery and resilience are related to changes in ecosystem turnover of materials, nutrient retention or loss, resource use efficiencies, and additional ecosystem properties that determine fluxes of carbon, water and nutrients. At landscape or regional scale, changes in system drivers influence land-surface to atmosphere gas exchange (water, carbon and trace gas emissions), the seasonal course of soil resource stores, hydrology, and transport of nutrients and carbon into and through river systems. In today's terminology, shifts in these fluxes indicate a modification of potential ecosystem services provided to us by the landscape or region of interest, and upon which we depend. Ongoing modeling efforts of the TERRECO project carried out in S. Korea focus on describing landscape and regional level flow networks for carbon, water, and nutrients, but in addition monetary flows associated with gains and losses in ecosystem services (cf. Fig. 1). The description is embedded within a framework which examines the trade-offs between agricultural intensification versus yield of high quality water to reservoirs for drinking water supply. The models also quantify hypothetical changes in flow networks that would occur in the context of climate, land use and social change scenarios.

Integrating ecosystem services into national Forest Service policy and operations

Science.gov (United States)

Robert Deal; Lisa Fong; Erin Phelps; Emily Weidner; Jonas Epstein; Tommie Herbert; Mary Snieckus; Nikola Smith; Tania Ellersick; Greg Arthaud

2017-01-01

The ecosystem services concept describes the many benefits people receive from nature. It highlights the importance of managing public and private lands sustainably to ensure these benefits continue into the future, and it closely aligns with the U.S. Forest Service (USFS) mission to “sustain the health, diversity, and productivity of the Nation’s forests and...

Head losses prediction and analysis in a bulb turbine draft tube under different operating conditions using unsteady simulations

Science.gov (United States)

Wilhelm, S.; Balarac, G.; Métais, O.; Ségoufin, C.

2016-11-01

Flow prediction in a bulb turbine draft tube is conducted for two operating points using Unsteady RANS (URANS) simulations and Large Eddy Simulations (LES). The inlet boundary condition of the draft tube calculation is a rotating two dimensional velocity profile exported from a RANS guide vane- runner calculation. Numerical results are compared with experimental data in order to validate the flow field and head losses prediction. Velocity profiles prediction is improved with LES in the center of the draft tube compared to URANS results. Moreover, more complex flow structures are obtained with LES. A local analysis of the predicted flow field using the energy balance in the draft tube is then introduced in order to detect the hydrodynamic instabilities responsible for head losses in the draft tube. In particular, the production of turbulent kinetic energy next to the draft tube wall and in the central vortex structure is found to be responsible for a large part of the mean kinetic energy dissipation in the draft tube and thus for head losses. This analysis is used in order to understand the differences in head losses for different operating points. The numerical methodology could then be improved thanks to an in-depth understanding of the local flow topology.

Mainstreaming Natural Capital into Decisions: Integrated Valuation of Ecosystem Services

Directory of Open Access Journals (Sweden)

Arnas Palaima

2013-08-01

Full Text Available The purpose of the article is to review current paradigms in ecosystem services valuation, existing gaps and current trends in addressing those gaps. Natural capital, often defined as the stock of natural ecosystems that yields a flow of valuable ecosystem goods or services into the future, is often undervalued or not valued at all by governments, business and society, which leads to environmental degradation and loss of biodiversity. One of the major reasons of such undervaluation is the lack of practical, realistic quantitative methods/models that would establish ecosystem services value and its change due to human development. A promising, recently developed ecosystem services modeling system is InVEST: “Integrated Valuation of Ecosystem Services and Trade-Offs.” InVEST is a set of Geographic Information Systems (GIS models that predict the provision and value of ecosystem services and habitat provision given land use/land cover maps and related biophysical, economic, and institutional data for the study region. InVEST, if further developed and applied in a systematic way, could facilitate mainstreaming the natural capital into decisions at all levels and provide a strong foundation for local natural resources managers to improve and optimize their environmental management strategies.

Food Web Response to Habitat Restoration in Various Coastal Wetland Ecosystems

Science.gov (United States)

James, W. R.; Nelson, J. A.

2017-12-01

Coastal wetland habitats provide important ecosystem services, including supporting coastal food webs. These habitats are being lost rapidly. To combat the effects of these losses, millions of dollars have been invested to restore these habitats. However, the relationship between restoring habitat and restoring ecosystem functioning is poorly understood. Analyzing energy flow through food web comparisons between restored and natural habitats can give insights into ecosystem functioning. Using published stable isotope values from organisms in restored and natural habitats, we assessed the food web response of habitat restoration in salt marsh, mangrove, sea grass, and algal bed ecosystems. We ran Bayesian mixing models to quantify resource use by consumers and generated habitat specific niche hypervolumes for each ecosystem to assess food web differences between restored and natural habitats. Salt marsh, mangrove, and sea grass ecosystems displayed functional differences between restored and natural habitats. Salt marsh and mangrove food webs varied in the amount of each resource used, while the sea grass food web displayed more variation between individual organisms. The algal bed food web showed little variation between restored and natural habitats.

Comparative review of multifunctionality and ecosystem services in sustainable agriculture.

Science.gov (United States)

Huang, Jiao; Tichit, Muriel; Poulot, Monique; Darly, Ségolène; Li, Shuangcheng; Petit, Caroline; Aubry, Christine

2015-02-01

Two scientific communities with broad interest in sustainable agriculture independently focus on multifunctional agriculture or ecosystem services. These communities have limited interaction and exchange, and each group faces research challenges according to independently operating paradigms. This paper presents a comparative review of published research in multifunctional agriculture and ecosystem services. The motivation for this work is to improve communication, integrate experimental approaches, and propose areas of consensus and dialog for the two communities. This extensive analysis of publication trends, ideologies, and approaches enables formulation of four main conclusions. First, the two communities are closely related through their use of the term "function." However, multifunctional agriculture considers functions as agricultural activity outputs and prefers farm-centred approaches, whereas ecosystem services considers ecosystem functions in the provision of services and prefers service-centred approaches. Second, research approaches to common questions in these two communities share some similarities, and there would be great value in integrating these approaches. Third, the two communities have potential for dialog regarding the bundle of ecosystem services and the spectrum of multifunctional agriculture, or regarding land sharing and land sparing. Fourth, we propose an integrated conceptual framework that distinguishes six groups of ecosystem services and disservices in the agricultural landscape, and combines the concepts of multifunctional agriculture and ecosystem services. This integrated framework improves applications of multifunctional agriculture and ecosystem services for operational use. Future research should examine if the framework can be readily adapted for modelling specific problems in agricultural management. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

OpenAIRE

Mo Shuqing; Zhang Xiufeng; Tang Yali; Liu Zhengwen; Kettridge Nicholas

2017-01-01

Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aer...

Biodiversity increases the resistance of ecosystem productivity to climate extremes.

Science.gov (United States)

Isbell, Forest; Craven, Dylan; Connolly, John; Loreau, Michel; Schmid, Bernhard; Beierkuhnlein, Carl; Bezemer, T Martijn; Bonin, Catherine; Bruelheide, Helge; de Luca, Enrica; Ebeling, Anne; Griffin, John N; Guo, Qinfeng; Hautier, Yann; Hector, Andy; Jentsch, Anke; Kreyling, Jürgen; Lanta, Vojtěch; Manning, Pete; Meyer, Sebastian T; Mori, Akira S; Naeem, Shahid; Niklaus, Pascal A; Polley, H Wayne; Reich, Peter B; Roscher, Christiane; Seabloom, Eric W; Smith, Melinda D; Thakur, Madhav P; Tilman, David; Tracy, Benjamin F; van der Putten, Wim H; van Ruijven, Jasper; Weigelt, Alexandra; Weisser, Wolfgang W; Wilsey, Brian; Eisenhauer, Nico

2015-10-22

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

Remote sensing and aerial photography for delineation and management of coastal ecosystems

Digital Repository Service at National Institute of Oceanography (India)

Jagtap, T.G.

sensing data. may provide necessary information to the planners and researchers. interested in the 11 .. coastal ecosystems. Mismanagement or lack of management of coastal zones may result in the loss of marine ecosystems, influencing erosion and the sea..., topographic maps and other resources. The effective management and research of coastal zones, require information on coastal landforms, wetlands, shoreline changes, sediment and current pattern, which can easily be obtained from the satellite data. Coastal...

Quantifying changes in multiple ecosystem services during 1992-2012 in the Sanjiang Plain of China.

Science.gov (United States)

Wang, Zongming; Mao, Dehua; Li, Lin; Jia, Mingming; Dong, Zhangyu; Miao, Zhenghong; Ren, Chunying; Song, Changchun

2015-05-01

Rapid and periodic assessment of the impact of land cover changes on ecosystem services at regional levels is essential to understanding services and sustainability of ecosystems. This study focused on quantifying and assessing changes of multiple ecosystem services in the Sanjiang Plain of China as a result of land cover changes over the period of 1992-2012. This region is important for its large area of natural wetlands and intensive agriculture. The ecosystem services that were assessed for this region included its regulating services (water yield and ecosystem carbon stocks), supporting services (suitable waterbird habitats), and provisioning services (food production), and the approach to the assessment was composed of the surface energy balance algorithms for land (SEBAL), soil survey re-sampling method and an empirical waterbird habitat suitability model. This large scale and integrated investigation represents the first systematic evaluation on the status of ecosystem carbon stocks in the Sanjiang Plain in addition to the development of an effective model for analysis of waterbird habitat suitability with the use of both remote sensing and geographic information systems (GIS). More importantly, the result from this study has confirmed trade-offs between ecosystem services and negative consequences to environment in this region. The trade-offs were typically manifested by increased water yield and significantly grown food production, which is in contrast with significant losses in ecosystem carbon stocks (-14%) and suitable waterbird habitats (-23%) mainly due to the conversion of land cover from wetland to farmland. This finding implies that land use planning and policy making for this economically important region should take ecosystem service losses into account in order to preserve its natural ecosystems in the best interest of society. Copyright © 2015 Elsevier B.V. All rights reserved.

Platform and Ecosystem Transitions: Strategic and Organizational Implications

OpenAIRE

Altman, Elizabeth J.

2015-01-01

By most conventional measures of corporate success (revenue, market capitalization, global brand growth, etc.) businesses operating as multi-sided platforms (MSPs) and their associated ecosystems constitute the majority of the fastest growing organizations in the global economy. In the strategy and economics fields there is a burgeoning literature related to MSP-governed businesses and their ecosystems primarily focused on pricing, growth, governance, and competitive considerations. Yet, in o...

Seed loss in prostate brachytherapy. Operator dependency and impact on dosimetry

Energy Technology Data Exchange (ETDEWEB)

El-Bared, Nancy; Sebbag, Natanel; Beliveau-Nadeau, Dominic; Hervieux, Yannick; Larouche, Renee; Taussky, Daniel; Delouya, Guila [Centre hospitalier de l' Universite de Montreal - Hopital Notre-Dame, Departement de Radio-Oncologie, Montreal, QC (Canada)

2016-05-15

The aim of our study was to review seed loss and its impact on dosimetry as well as the influence of the treating physician on seed loss and dosimetry in patients treated with prostate brachytherapy using permanent loose {sup 125}I implant. We analyzed 1087 consecutive patients treated by two physicians between July 2005 and April 2015 at a single institution. Pelvic fluoroscopic imaging was done 30 days post implant and a chest X-ray when seed loss was observed. Seed loss occurred in 19.4 % of patients: in 20.0 % of implants done by the most experienced physician and in 17.2 % by the less experienced physician (p = 0.4) and migration to the thorax occurred in 5.9 % (6.9 vs. 2.2 %, p = 0.004). The mean seed loss rate was 0.57 % [standard deviation (SD) 1.39] and the mean rate of seeds in the thorax was 0.14 % (SD 0.65). The most experienced physician had a higher mean number of seeds lost: 0.36 versus 0.25 (p = 0.055), and a higher mean number of seed migration to the thorax: 0.1 versus 0.02 (p < 0.001). When at least one seed was lost, a decrease of 4.2 Gy (p < 0.001) in the D90 and a decrease of 3.5 % (p = 0.002) in the V150 was observed. We found a significant decrease in V150 and D90 with the occurrence of seed loss. Furthermore, we found a difference in seed migration among the physicians demonstrating that seed loss is operator dependant. (orig.) [German] Wir analysierten den Prozentsatz des Seed-Verlusts sowie den Einfluss von Arzterfahrung und Seed-Abgang auf die Dosimetrie bei Patienten, die mit einer Prostata-Brachytherapie mit permanent beweglichen {sup 125}I-Implantaten behandelt wurden. Eingeschlossen in diese Studie wurden alle zwischen Juli 2005 und April 2015 an unserem Krankenhaus von zwei Aerzten konsekutiv behandelten 1087 Patienten. Anhand fluoroskopischer Bilder wurden noch vorhandene Seeds 30 Tage nach dem Eingriff gezaehlt. Bei unvollstaendiger Seed-Anzahl wurde ein Thorax-Roentgenbild angefertigt. In 19% der Patienten ging mindestens ein

Ecosystem transformation by emerging infectious disease: loss of large tanoak from California forests

Science.gov (United States)

Richard C. Cobb; Joao A.N. Filipe; Ross K. Meentemeyer; Christopher A. Gilligan; David M. Rizzo

2012-01-01

1. Few pathogens are the sole or primary cause of species extinctions, but forest disease has caused spectacular declines in North American overstorey trees and restructured forest ecosystems at large spatial scales over the past 100 years. These events threaten biodiversity associated with impacted host trees and other resources valued by human societies even when...

The economics of ecosystems and biodiversity, REDD+ and climate change in mangrove ecosystems of Southeast Asia

Directory of Open Access Journals (Sweden)

Filiberto Pollisco

2013-07-01

Full Text Available Mangroves are trees and shrubs that grow in saline coastal habitats. They occupy large stretches of the sub-tropical and tropical coastlines around the world. They not only provide valuable goods such as timber, fish and medicinal plants but also vital ecological services, such as prevention of coastal erosion. They also help buffer coastal communities from storms and floods. During the ASEAN Conference on Biodiversity held in Singapore in 2009, Ellison reported that mangrove forests in South East Asia are among the highest biodiversity resources in the world, occupying an area of 60.9 x 102 km2. Unfortunately, the region also has the highest rates of mangrove loss in the world, losing 628 km2 per year in two decades. In many parts of the world, where mangrove forests have been cleared, there are now problems of erosion and siltation, and loss of life and property have occurred due to destructive hurricanes, storms and tsunamis. The complex relationship between climate change and mangrove ecosystems can be seen from two different angles. On the one hand, mangrove ecosystems have a critical function in combating climate change; on the other hand, they are affected by climate change. The values of ecosystems vary according to local biophysical and ecological circumstances and the social, economic and cultural context. Intangible values, which may be reflected in society’s willingness to pay to conserve particular species or landscapes, or to protect common resources, must be considered alongside more tangible values such as food or timber to provide a complete economic picture. This has important implications for mangrove conservation strategies and suggests that the preservation of contiguous areas is preferable to patches that are spatially dispersed.

EnviroAtlas - Ecosystem Service Market and Project Locations, U.S., 2015, Forest Trends' Ecosystem Marketplace

Science.gov (United States)

This EnviroAtlas dataset contains points depicting the location of market-based programs, referred to herein as markets, and projects addressing ecosystem services protection in the United States. The data were collected via surveys and desk research conducted by Forest Trends' Ecosystem Marketplace from 2008 to 2016 on biodiversity (i.e., imperiled species/habitats; wetlands and streams), carbon, and water markets. Additional biodiversity data were obtained from the Regulatory In-lieu Fee and Bank Information Tracking System (RIBITS) database in 2015. Points represent the centroids (i.e., center points) of market coverage areas, project footprints, or project primary impact areas in which ecosystem service markets or projects operate. National-level markets are an exception to this norm with points representing administrative headquarters locations. Attribute data include information regarding the methodology, design, and development of biodiversity, carbon, and water markets and projects. This dataset was produced by Forest Trends' Ecosystem Marketplace for EnviroAtlas in order to support public access to and use of information related to environmental markets. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) o

ITER SAFETY TASK NID-5D: Operational tritium loss and accident investigation for heat transport and water detritiation systems

International Nuclear Information System (INIS)

Kalyanam, K.M.; Fong, C.; Moledina, M.; Natalizio, A.

1995-02-01

The task objectives are to: a) determine major pathways for tritium loss during normal operation of the cooling systems and water detritiation system, b) estimate operational losses and environmental tritium releases from the heat transport and water detritiation systems of ITER, and c) prepare a preliminary Failure Modes and Effects Analysis (FMEA) for the ITER Water Detritiation System. The analysis will be used to estimate chronic environmental tritium releases (airborne and waterborne) for the ITER Cooling Systems and Water Detritiation System. The assessment will form the basis for demonstrating the acceptability of ITER for siting in the Early Safety and Environmental Characterization Study (ESECS), to be issued in early 1995. (author). 7 refs., 10 tabs., 11 figs

TOWARDS THE LEGAL RECOGNITION AND GOVERNANCE OF FOREST ECOSYSTEM SERVICES IN MOZAMBIQUE

Directory of Open Access Journals (Sweden)

S Norfolk

2013-06-01

Full Text Available Within the context of Mozambique, this paper examines the state of forest ecosystem services, the dependency of the population on these systems for their well-being, if an adaptive governance regime is being created which will ensure the resilience of the forest ecosystem services including the legal framework, the institutions operating within this framework, the tools available and their functioning, and how cooperative governance is operating.

Hierarchical Synthesis of Coastal Ecosystem Health Indicators at Karimunjawa National Marine Park

Science.gov (United States)

Danu Prasetya, Johan; Ambariyanto; Supriharyono; Purwanti, Frida

2018-02-01

The coastal ecosystem of Karimunjawa National Marine Park (KNMP) is facing various pressures, including from human activity. Monitoring the health condition of coastal ecosystems periodically is needed as an evaluation of the ecosystem condition. Systematic and consistent indicators are needed in monitoring of coastal ecosystem health. This paper presents hierarchical synthesis of coastal ecosystem health indicators using Analytic Hierarchy Process (AHP) method. Hierarchical synthesis is obtained from process of weighting by paired comparison based on expert judgments. The variables of coastal ecosystem health indicators in this synthesis consist of 3 level of variable, i.e. main variable, sub-variable and operational variable. As a result of assessment, coastal ecosystem health indicators consist of 3 main variables, i.e. State of Ecosystem, Pressure and Management. Main variables State of Ecosystem and Management obtain the same value i.e. 0.400, while Pressure value was 0.200. Each main variable consist of several sub-variable, i.e. coral reef, reef fish, mangrove and seagrass for State of Ecosystem; fisheries and marine tourism activity for Pressure; planning and regulation, institutional and also infrastructure and financing for Management. The highest value of sub-variable of main variable State of Ecosystem, Pressure and Management were coral reef (0.186); marine tourism pressure (0.133) and institutional (0.171), respectively. The highest value of operational variable of main variable State of Ecosystem, Pressure and Management were percent of coral cover (0.058), marine tourism pressure (0.133) and presence of zonation plan, regulation also socialization of monitoring program (0.53), respectively. Potential pressure from marine tourism activity is the variable that most affect the health of the ecosystem. The results of this research suggest that there is a need to develop stronger conservation strategies to facing with pressures from marine tourism

Prediction of prestressing losses for long term operation of nuclear reactor buildings

Directory of Open Access Journals (Sweden)

Thillard G.

2011-04-01

Full Text Available Prestressed concrete is used in nuclear reactor buildings to guarantee containment and structural integrity in case of an accident. Monitoring and operating experience over 40 years has shown that prestressing losses can be much greater than the design estimation based on the usual standard laws. A method was developed to determine the realistic residual prestress level in structures, in particular for those where no embedded instrumentation was installed, taking into account in situ measurement results rather than design characteristics. The results can enable the owner to justify extending the lifespan while guaranteeing adequate safety and to define and plan adequate maintenance actions.

Maintaining ecosystem resilience: functional responses of tree cavity nesters to logging in temperate forests of the Americas.

Science.gov (United States)

Ibarra, José Tomás; Martin, Michaela; Cockle, Kristina L; Martin, Kathy

2017-06-30

Logging often reduces taxonomic diversity in forest communities, but little is known about how this biodiversity loss affects the resilience of ecosystem functions. We examined how partial logging and clearcutting of temperate forests influenced functional diversity of birds that nest in tree cavities. We used point-counts in a before-after-control-impact design to examine the effects of logging on the value, range, and density of functional traits in bird communities in Canada (21 species) and Chile (16 species). Clearcutting, but not partial logging, reduced diversity in both systems. The effect was much more pronounced in Chile, where logging operations removed critical nesting resources (large decaying trees), than in Canada, where decaying aspen Populus tremuloides were retained on site. In Chile, logging was accompanied by declines in species richness, functional richness (amount of functional niche occupied by species), community-weighted body mass (average mass, weighted by species densities), and functional divergence (degree of maximization of divergence in occupied functional niche). In Canada, clearcutting did not affect species richness but nevertheless reduced functional richness and community-weighted body mass. Although some cavity-nesting birds can persist under intensive logging operations, their ecosystem functions may be severely compromised unless future nest trees can be retained on logged sites.

Marine biodiversity-ecosystem functions under uncertain environmental futures.

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Bulling, Mark T; Hicks, Natalie; Murray, Leigh; Paterson, David M; Raffaelli, Dave; White, Piran C L; Solan, Martin

2010-07-12

Anthropogenic activity is currently leading to dramatic transformations of ecosystems and losses of biodiversity. The recognition that these ecosystems provide services that are essential for human well-being has led to a major interest in the forms of the biodiversity-ecosystem functioning relationship. However, there is a lack of studies examining the impact of climate change on these relationships and it remains unclear how multiple climatic drivers may affect levels of ecosystem functioning. Here, we examine the roles of two important climate change variables, temperature and concentration of atmospheric carbon dioxide, on the relationship between invertebrate species richness and nutrient release in a model benthic estuarine system. We found a positive relationship between invertebrate species richness and the levels of release of NH(4)-N into the water column, but no effect of species richness on the release of PO(4)-P. Higher temperatures and greater concentrations of atmospheric carbon dioxide had a negative impact on nutrient release. Importantly, we found significant interactions between the climate variables, indicating that reliably predicting the effects of future climate change will not be straightforward as multiple drivers are unlikely to have purely additive effects, resulting in increased levels of uncertainty.

Marine biodiversity–ecosystem functions under uncertain environmental futures

Science.gov (United States)

Bulling, Mark T.; Hicks, Natalie; Murray, Leigh; Paterson, David M.; Raffaelli, Dave; White, Piran C. L.; Solan, Martin

2010-01-01

Anthropogenic activity is currently leading to dramatic transformations of ecosystems and losses of biodiversity. The recognition that these ecosystems provide services that are essential for human well-being has led to a major interest in the forms of the biodiversity–ecosystem functioning relationship. However, there is a lack of studies examining the impact of climate change on these relationships and it remains unclear how multiple climatic drivers may affect levels of ecosystem functioning. Here, we examine the roles of two important climate change variables, temperature and concentration of atmospheric carbon dioxide, on the relationship between invertebrate species richness and nutrient release in a model benthic estuarine system. We found a positive relationship between invertebrate species richness and the levels of release of NH4-N into the water column, but no effect of species richness on the release of PO4-P. Higher temperatures and greater concentrations of atmospheric carbon dioxide had a negative impact on nutrient release. Importantly, we found significant interactions between the climate variables, indicating that reliably predicting the effects of future climate change will not be straightforward as multiple drivers are unlikely to have purely additive effects, resulting in increased levels of uncertainty. PMID:20513718

Functional complexity and ecosystem stability: an experimental approach

Energy Technology Data Exchange (ETDEWEB)

Van Voris, P.; O' Neill, R.V.; Shugart, H.H.; Emanuel, W.R.

1978-01-01

The complexity-stability hypothesis was experimentally tested using intact terrestrial microcosms. Functional complexity was defined as the number and significance of component interactions (i.e., population interactions, physical-chemical reactions, biological turnover rates) influenced by nonlinearities, feedbacks, and time delays. It was postulated that functional complexity could be nondestructively measured through analysis of a signal generated from the system. Power spectral analysis of hourly CO/sub 2/ efflux, from eleven old-field microcosms, was analyzed for the number of low frequency peaks and used to rank the functional complexity of each system. Ranking of ecosystem stability was based on the capacity of the system to retain essential nutrients and was measured by net loss of Ca after the system was stressed. Rank correlation supported the hypothesis that increasing ecosystem functional complexity leads to increasing ecosystem stability. The results indicated that complex functional dynamics can serve to stabilize the system. The results also demonstrated that microcosms are useful tools for system-level investigations.

Ecosystem-based management of a Mediterranean urban wastewater system: a sensitivity analysis of the operational degrees of freedom.

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Corominas, Lluís; Neumann, Marc B

2014-10-01

Urban wastewater systems discharge organic matter, nutrients and other pollutants (including toxic substances) to receiving waters, even after removing more than 90% of incoming pollutants from human activities. Understanding their interactions with the receiving water bodies is essential for the implementation of ecosystem-based management strategies. Using mathematical modeling and sensitivity analysis we quantified how 19 operational variables of an urban wastewater system affect river water quality. The mathematical model of the Congost system (in the Besòs catchment, Spain) characterizes the dynamic interactions between sewers, storage tanks, wastewater treatment plants and the river. The sensitivity analysis shows that the use of storage tanks for peak shaving and the use of a connection between two neighboring wastewater treatment plants are the most important factors influencing river water quality. We study how the sensitivity of the water quality variables towards changes in the operational variables varies along the river due to discharge locations and river self-purification processes. We demonstrate how to use the approach to identify interactions and how to discard non-influential operational variables. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radiation exposure of aquatic ecosystem compartments

International Nuclear Information System (INIS)

Colonna-Cesari-Florent, L.; Bontoux, J.

1999-01-01

In the frame of a normal operation, a nuclear site releases gaseous as well liquid effluents in environment. Limits are defined but if they are acceptable for man, do they allow to preserve species of ecosystem? Two points stand out of this study: the natural radioactivity is dominating in exposure but can one neglect an addition of artificial radioactivity? The species of Rhone river ecosystem are potentially submitted to a thermal and/or chemical stress, only a combined study, taking into account every situation of stress, could lead to a long term preservation of our environmental inheritance. (N.C.)

Forest restoration, biodiversity and ecosystem functioning

Science.gov (United States)

2011-01-01

Globally, forests cover nearly one third of the land area and they contain over 80% of terrestrial biodiversity. Both the extent and quality of forest habitat continue to decrease and the associated loss of biodiversity jeopardizes forest ecosystem functioning and the ability of forests to provide ecosystem services. In the light of the increasing population pressure, it is of major importance not only to conserve, but also to restore forest ecosystems. Ecological restoration has recently started to adopt insights from the biodiversity-ecosystem functioning (BEF) perspective. Central is the focus on restoring the relation between biodiversity and ecosystem functioning. Here we provide an overview of important considerations related to forest restoration that can be inferred from this BEF-perspective. Restoring multiple forest functions requires multiple species. It is highly unlikely that species-poor plantations, which may be optimal for above-ground biomass production, will outperform species diverse assemblages for a combination of functions, including overall carbon storage and control over water and nutrient flows. Restoring stable forest functions also requires multiple species. In particular in the light of global climatic change scenarios, which predict more frequent extreme disturbances and climatic events, it is important to incorporate insights from the relation between biodiversity and stability of ecosystem functioning into forest restoration projects. Rather than focussing on species per se, focussing on functional diversity of tree species assemblages seems appropriate when selecting tree species for restoration. Finally, also plant genetic diversity and above - below-ground linkages should be considered during the restoration process, as these likely have prominent but until now poorly understood effects at the level of the ecosystem. The BEF-approach provides a useful framework to evaluate forest restoration in an ecosystem functioning context, but

Biodiversity losses and conservation responses in the Anthropocene.

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Johnson, Christopher N; Balmford, Andrew; Brook, Barry W; Buettel, Jessie C; Galetti, Mauro; Guangchun, Lei; Wilmshurst, Janet M

2017-04-21

Biodiversity is essential to human well-being, but people have been reducing biodiversity throughout human history. Loss of species and degradation of ecosystems are likely to further accelerate in the coming years. Our understanding of this crisis is now clear, and world leaders have pledged to avert it. Nonetheless, global goals to reduce the rate of biodiversity loss have mostly not been achieved. However, many examples of conservation success show that losses can be halted and even reversed. Building on these lessons to turn the tide of biodiversity loss will require bold and innovative action to transform historical relationships between human populations and nature. Copyright © 2017, American Association for the Advancement of Science.

Major losses of nutrients following a severe drought in a boreal forest.

Science.gov (United States)

Houle, Daniel; Lajoie, Geneviève; Duchesne, Louis

2016-11-28

Because of global warming, the frequency and severity of droughts are expected to increase, which will have an impact on forest ecosystem health worldwide 1 . Although the impact of drought on tree growth and mortality is being increasingly documented 2-4 , very little is known about the impact on nutrient cycling in forest ecosystems. Here, based on long-term monitoring data, we report nutrient fluxes in a boreal forest before, during and following a severe drought in July 2012. During and shortly after the drought, we observed high throughfall (rain collected below the canopy) concentrations of nutrient base cations (potassium, calcium and magnesium), chlorine, phosphorus and dissolved organic carbon (DOC), differing by one to two orders of magnitude relative to the long-term normal, and resulting in important canopy losses. The high throughfall fluxes had repercussions in the soil solution at a depth of 30 cm, leading to high DOC, chlorine and potassium concentrations. The net potassium losses (atmospheric deposition minus leaching losses) following the drought were especially important, being the equivalent of nearly 20 years of net losses under 'normal' conditions. Our data show that droughts have unexpected impacts on nutrient cycling through impacts on tree canopy and soils and may lead to important episodes of potassium losses from boreal forest ecosystems. The potassium losses associated with drought will add to those originating from tree harvesting and from forest fires and insect outbreaks 5-7 (with the last two being expected to increase in the future as a result of climate change), and may contribute to reduced potassium availability in boreal forests in a warming world.

Biodiversity losses: The downward spiral

Science.gov (United States)

Tomback, Diana F.; Kendall, Katherine C.; Tomback, Diana F.; Arno, Stephen F.; Keane, Robert E.

2001-01-01

The dramatic decline of whitebark pine (Pinus albicaulis) populations in the northwestern United States and southwestern Canada from the combined effects of fire exclusion, mountain pine beetles (Dendroctonus ponderosae), and white pine blister rust (Cronartium ribicola), and the projected decline of whitebark pine populations rangewide (Chapters 10 and 11) do not simply add up to local extirpations of a single tree species. Instead, the loss of whitebark pine has broad ecosystem-level consequences, eroding local plant and animal biodiversity, changing the time frame of succession, and altering the distribution of subalpine vegetation (Chapter 1). One potential casualty of this decline may be the midcontinental populations of the grizzly bear (Ursus arctos horribilis), which use whitebark pine seeds as a major food source (Chapter 7). Furthermore, whitebark pine is linked to other white pine ecosystems in the West through its seed-disperser, Clark's nutcracker (Nucifraga columbiana) (Chapter 5). Major declines in nutcracker populations ultimately seal the fate of several white pine ecosystems, and raise the question of whether restoration is possible once a certain threshold of decline is reached.

Integrating forest products with ecosystem services: a global perspective

Science.gov (United States)

Robert L. Deal; Rachel. White

2012-01-01

Around the world forests provide a broad range of vital ecosystem services. Sustainable forest management and forest products play an important role in global carbon management, but one of the major forestry concerns worldwide is reducing the loss of forestland from development. Currently, deforestation accounts for approximately 20% of total greenhouse gas emissions....

Payments for ecosystem services and the financing of global biodiversity conservation

NARCIS (Netherlands)

Hein, L.G.; Miller, D.C.; Groot, de R.S.

2013-01-01

It is generally recognized that addressing the ongoing loss of global biodiversity requires a substantial increase in funding for conservation activities, particularly in developing countries. An increasing interest in Payment Mechanisms for Ecosystem Services (PES) begs the question of whether a

Ecosystem services and economic theory: integration for policy-relevant research.

Science.gov (United States)

Fisher, Brendan; Turner, Kerry; Zylstra, Matthew; Brouwer, Roy; de Groot, Rudolf; Farber, Stephen; Ferraro, Paul; Green, Rhys; Hadley, David; Harlow, Julian; Jefferiss, Paul; Kirkby, Chris; Morling, Paul; Mowatt, Shaun; Naidoo, Robin; Paavola, Jouni; Strassburg, Bernardo; Yu, Doug; Balmford, Andrew

2008-12-01

It has become essential in policy and decision-making circles to think about the economic benefits (in addition to moral and scientific motivations) humans derive from well-functioning ecosystems. The concept of ecosystem services has been developed to address this link between ecosystems and human welfare. Since policy decisions are often evaluated through cost-benefit assessments, an economic analysis can help make ecosystem service research operational. In this paper we provide some simple economic analyses to discuss key concepts involved in formalizing ecosystem service research. These include the distinction between services and benefits, understanding the importance of marginal ecosystem changes, formalizing the idea of a safe minimum standard for ecosystem service provision, and discussing how to capture the public benefits of ecosystem services. We discuss how the integration of economic concepts and ecosystem services can provide policy and decision makers with a fuller spectrum of information for making conservation-conversion trade-offs. We include the results from a survey of the literature and a questionnaire of researchers regarding how ecosystem service research can be integrated into the policy process. We feel this discussion of economic concepts will be a practical aid for ecosystem service research to become more immediately policy relevant.

Navigating Risk When Entering and Participating in a Business Ecosystem

Directory of Open Access Journals (Sweden)

Derek Smith

2013-05-01

Full Text Available Entrepreneurs typically have limited resources during the start-up phase of a business. Business ecosystems are a strategy for entrepreneurs to access and exchange many different aspects of value, resources, and benefits. However, there may be business risks for entering a particular type of ecosystem, and further risks may be encountered after entering and participating in a business ecosystem. These risks are significant and can inhibit a startup's growth. In this article, the literature on business ecosystems is reviewed as it relates to risk to discover insights of relevance to entrepreneurs, top management teams, and business-ecosystem operators. First, the published research is organized into two streams: i risks relating to categories of business ecosystems, and ii risks relating to participating in business ecosystems. Then, the problem is abstracted to develop a potential strategy for managing these risks, which features a pre-entry inspection followed by real-time resource management. Finally, five recommendations are offered for entrepreneurs seeking to enter and participate in business ecosystems.

Relative blood loss and operative time can predict length of stay following orthognathic surgery.

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Andersen, K; Thastum, M; Nørholt, S E; Blomlöf, J

2016-10-01

The aim of this study was to investigate the length of stay (LOS) following orthognathic surgery and thereby to establish a benchmark. The secondary aim was to identify predictors of postoperative LOS following orthognathic surgery. Patients were treated consecutively during the period 2010 to 2012. Inclusion criteria were (1) patient age ≥18 years, and (2) surgery involving a three-piece Le Fort I osteotomy, or a bilateral sagittal split osteotomy (BSSO), or bimaxillary surgery. A total of 335 patients were included. The following data were recorded: height, weight, body mass index (BMI), age, sex, operative time, intraoperative blood loss, and type of surgery. LOS was defined as the duration of time from date of surgery to date of discharge. The average LOS was 1.3 days following Le Fort I osteotomy, 1.3 days following BSSO, and 1.8 days following bimaxillary surgery. In the multivariate regression model (R(2)=0.11), predictors of a prolonged LOS were operative time (P<0.001) and relative blood loss (P=0.002). No significant effect of age, BMI, sex, or treatment on LOS was observed. The short duration of LOS found in this study supports the possibility of increasing outpatient pathways for selected patients. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Seagrass Ecosystem Services and Their Variability across Genera and Geographical Regions.

Science.gov (United States)

Mtwana Nordlund, Lina; Koch, Evamaria W; Barbier, Edward B; Creed, Joel C

2016-01-01

Threats to and loss of seagrass ecosystems globally, impact not only natural resources but also the lives of people who directly or indirectly depend on these systems. Seagrass ecosystems play a multi-functional role in human well-being, e.g. food through fisheries, control of erosion and protection against floods. Quantifying these services reveals their contributions to human well-being and helps justify seagrass conservation. There has been no comprehensive assessment as to whether seagrass ecosystem services are perceived to vary over the globe or amongst genera. Our study compiles the most complete list of ecosystem services provided by seagrasses so far, including bioregional- and genus-specific information from expert opinion and published studies. Several seagrass ecosystem services vary considerably in their (known) provision across genera and over the globe. Seagrasses genera are clearly not all equal with regard to the ecosystem services they provide. As seagrass genera are not evenly distributed over all bioregions, the presence of an ecosystem service sometimes depends on the genera present. Larger sized seagrass genera (e.g. Posidonia, Enhalus) are perceived to provide more substantial and a wider variety of ecosystem services than smaller species (e.g. Halophila, Lepilaena). Nevertheless, smaller species provide important services. Our findings point out data gaps, provide new insight for more efficient management and recommend caution in economic valuation of seagrass services worldwide.

Are Wind Power and Hydropower Complements or Competitors? An Analysis of Ecosystem Service Constraints in the Roanoke Basin

Science.gov (United States)

Reed, P. M.; Fernandez, A. R.; Blumsack, S.

2011-12-01

Hydropower can provide inexpensive, flexible fill-in power to compensate for intermittent renewable generation. Policies for hydropower dams maintain multiple services beyond electric generation, including environmental protection, flood control and recreation. We model the decision of a hydroelectric generator to shift some of its power production capacity away from the day-ahead energy market into a "wind-following" service that smoothes the intermittent production of wind turbines. Offering such a service imposes both private and social opportunity costs. Since fluctuations in wind energy output are not perfectly correlated with day-ahead energy prices, a wind-following service will necessarily affect generator revenues. Seasonal wind patterns produce conflicts with the goal of managing rivers for "ecosystem services" - the maintenance or enhancement of downstream ecosystems. We illustrate our decision model using the Kerr Dam in PJM's territory in North Carolina. We simulate the operation of Kerr Dam over a three-year period that features hydrologic variability from normal water years to extreme drought conditions. We use an optimization framework to estimate reservation prices for Kerr Dam offering wind-following services in the PJM market. Wind-following may be profitable for Kerr Dam at low capacity levels during some time periods if ecosystems services are neglected and if side payments, or reserves-type payments, are provided. Wind-following with ecosystem services yields revenue losses that typically cannot be recovered with reserves market payments. Water release patterns are inconsistent with ecosystem-services goals when Kerr Dam dedicates significant capacity to wind-following, particularly in drought years.

Hydroeconomic Analysis of the Balance between Renewable Wind Energy, Hydropower, and Ecosystems Services in the Roanoke River Basin

Science.gov (United States)

Fernandez, A.; Blumsack, S.; Reed, P.

2012-04-01

Hydropower can provide inexpensive, flexible fill-in power to compensate for intermittent renewable generation. Policies for hydropower dams maintain multiple services beyond electric generation, including environmental protection, flood control and recreation. We model the decision of a hydroelectric generator to shift some of its power production capacity away from the day-ahead energy market into a "wind-following" service that smoothes the intermittent production of wind turbines. Offering such a service imposes both private and social opportunity costs. Since fluctuations in wind energy output are not perfectly correlated with day-ahead energy prices, a wind-following service will necessarily affect generator revenues. Seasonal wind patterns produce conflicts with the goal of managing rivers for "ecosystem services" - the maintenance or enhancement of downstream ecosystems. We illustrate our decision model using the Kerr Dam in PJM's territory in North Carolina. We simulate the operation of Kerr Dam over a three-year period that features hydrologic variability from normal water years to extreme drought conditions. We use an optimization framework to estimate reservation prices for Kerr Dam offering wind-following services in the PJM market. Wind-following may be profitable for Kerr Dam at low capacity levels during some time periods if ecosystems services are neglected and if side payments, or reserves-type payments, are provided. Wind-following with ecosystem services yields revenue losses that typically cannot be recovered with reserves market payments. Water release patterns are inconsistent with ecosystem-services goals when Kerr Dam dedicates significant capacity to wind-following, particularly in drought years.

Ecosystem stability in space: α, β and γ variability.

Science.gov (United States)

Wang, Shaopeng; Loreau, Michel

2014-08-01

The past two decades have seen great progress in understanding the mechanisms of ecosystem stability in local ecological systems. There is, however, an urgent need to extend existing knowledge to larger spatial scales to match the scale of management and conservation. Here, we develop a general theoretical framework to study the stability and variability of ecosystems at multiple scales. Analogously to the partitioning of biodiversity, we propose the concepts of alpha, beta and gamma variability. Gamma variability at regional (metacommunity) scale can be partitioned into local alpha variability and spatial beta variability, either multiplicatively or additively. On average, variability decreases from local to regional scales, which creates a negative variability-area relationship. Our partitioning framework suggests that mechanisms of regional ecosystem stability can be understood by investigating the influence of ecological factors on alpha and beta variability. Diversity can provide insurance effects at the various levels of variability, thus generating alpha, beta and gamma diversity-stability relationships. As a consequence, the loss of biodiversity and habitat impairs ecosystem stability at the regional scale. Overall, our framework enables a synthetic understanding of ecosystem stability at multiple scales and has practical implications for landscape management. © 2014 John Wiley & Sons Ltd/CNRS.

Earth Observation Data for Mapping and Evaluation of Ecosystem Services to Improve Human Livelihoods and Conserve Species

Science.gov (United States)

Shapiro, Aurelie C.; Bhagabati, Nirmal

2010-12-01

Mapping and evaluating ecosystem services is of increasing concern and urgency for conservation organizations such as WWF. Coupling biodiversity assessments with ecosystem services e.g., carbon sequestration, water regulation, sediment reduction, is an effective way to visualize additional financial and human benefits of conservation for decision makers. WWF is eager to apply various Earth Observation data to conservation applications for consistent mapping and monitoring of natural ecosystems and the potential impacts of their loss on humans and wildlife alike. Such examples include forest carbon mapping, integrated evaluation of ecosystem services (via the InVEST tool) and bundling endangered Tiger habitat with various ecosystem services for bundled benefits.

Operative blood loss and the frequency of haemorrhage associated with adenotonsillectomy in children: a double-blind trial of ethamsylate.

Science.gov (United States)

Arora, Y R; Manford, M L

1979-06-01

One hundred children were allocated randomly to receive either ethamsylate (Dicynene) or a placebo before undergoing adenotonsillectomy. Blood loss at operation was estimated from the haemoglobin content of swabs and aspirated fluid. Mean blood loss in the ethamsylate-treated group was not significantly less than in the controls. The frequency of secondary haemorrhage was significantly less in children treated with ethamsylate (P less than 0.01). No side-effects were reported in either group.

Stream hydrology limits recovery of riparian ecosystems after wolf reintroduction.

Science.gov (United States)

Marshall, Kristin N; Hobbs, N Thompson; Cooper, David J

2013-04-07

Efforts to restore ecosystems often focus on reintroducing apex predators to re-establish coevolved relationships among predators, herbivores and plants. The preponderance of evidence for indirect effects of predators on terrestrial plant communities comes from ecosystems where predators have been removed. Far less is known about the consequences of their restoration. The effects of removal and restoration are unlikely to be symmetrical because removing predators can create feedbacks that reinforce the effects of predator loss. Observational studies have suggested that the reintroduction of wolves to Yellowstone National Park initiated dramatic restoration of riparian ecosystems by releasing willows from excessive browsing by elk. Here, we present results from a decade-long experiment in Yellowstone showing that moderating browsing alone was not sufficient to restore riparian zones along small streams. Instead, restoration of willow communities depended on removing browsing and restoring hydrological conditions that prevailed before the removal of wolves. The 70-year absence of predators from the ecosystem changed the disturbance regime in a way that was not reversed by predator reintroduction. We conclude that predator restoration may not quickly repair effects of predator removal in ecosystems.

Competition favors elk over beaver in a riparian willow ecosystem

Science.gov (United States)

Baker, B.W.; Peinetti, H.R.; Coughenour, M.C.; Johnson, T.L.

2012-01-01

Beaver (Castor spp.) conservation requires an understanding of their complex interactions with competing herbivores. Simulation modeling offers a controlled environment to examine long-term dynamics in ecosystems driven by uncontrollable variables. We used a new version of the SAVANNA ecosystem model to investigate beaver (C. Canadensis) and elk (Cervus elapses) competition for willow (Salix spp.). We initialized the model with field data from Rocky Mountain National Park, Colorado, USA, to simulate a 4-ha riparian ecosystem containing beaver, elk, and willow. We found beaver persisted indefinitely when elk density was or = 30 elk km_2. The loss of tall willow preceded rapid beaver declines, thus willow condition may predict beaver population trajectory in natural environments. Beaver were able to persist with slightly higher elk densities if beaver alternated their use of foraging sites in a rest-rotation pattern rather than maintained continuous use. Thus, we found asymmetrical competition for willow strongly favored elk over beaver in a simulated montane ecosystem. Finally, we discuss application of the SAVANNA model and mechanisms of competition relative to beaver persistence as metapopulations, ecological resistance and alternative state models, and ecosystem regulation.

An invasive foundation species enhances multifunctionality in a coastal ecosystem.

Science.gov (United States)

Ramus, Aaron P; Silliman, Brian R; Thomsen, Mads S; Long, Zachary T

2017-08-08

While invasive species often threaten biodiversity and human well-being, their potential to enhance functioning by offsetting the loss of native habitat has rarely been considered. We manipulated the abundance of the nonnative, habitat-forming seaweed Gracilaria vermiculophylla in large plots (25 m 2 ) on southeastern US intertidal landscapes to assess impacts on multiple ecosystem functions underlying coastal ecosystem services. We document that in the absence of native habitat formers, this invasion has an overall positive, density-dependent impact across a diverse set of ecosystem processes (e.g., abundance and richness of nursery taxa, flow attenuation). Manipulation of invader abundance revealed both thresholds and saturations in the provisioning of ecosystem functions. Taken together, these findings call into question the focus of traditional invasion research and management that assumes negative effects of nonnatives, and emphasize the need to consider context-dependence and integrative measurements when assessing the impact of an invader, including density dependence, multifunctionality, and the status of native habitat formers. This work supports discussion of the idea that where native foundation species have been lost, invasive habitat formers may be considered as sources of valuable ecosystem functions.

Climate and fishing steer ecosystem regeneration to uncertain economic futures

Science.gov (United States)

Blenckner, Thorsten; Llope, Marcos; Möllmann, Christian; Voss, Rudi; Quaas, Martin F.; Casini, Michele; Lindegren, Martin; Folke, Carl; Chr. Stenseth, Nils

2015-01-01

Overfishing of large predatory fish populations has resulted in lasting restructurings of entire marine food webs worldwide, with serious socio-economic consequences. Fortunately, some degraded ecosystems show signs of recovery. A key challenge for ecosystem management is to anticipate the degree to which recovery is possible. By applying a statistical food-web model, using the Baltic Sea as a case study, we show that under current temperature and salinity conditions, complete recovery of this heavily altered ecosystem will be impossible. Instead, the ecosystem regenerates towards a new ecological baseline. This new baseline is characterized by lower and more variable biomass of cod, the commercially most important fish stock in the Baltic Sea, even under very low exploitation pressure. Furthermore, a socio-economic assessment shows that this signal is amplified at the level of societal costs, owing to increased uncertainty in biomass and reduced consumer surplus. Specifically, the combined economic losses amount to approximately 120 million € per year, which equals half of today's maximum economic yield for the Baltic cod fishery. Our analyses suggest that shifts in ecological and economic baselines can lead to higher economic uncertainty and costs for exploited ecosystems, in particular, under climate change. PMID:25694626

Ecosystem-based management and the wealth of ecosystems

Science.gov (United States)

Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K.; Fenichel, Eli P.

2017-01-01

We merge inclusive wealth theory with ecosystem-based management (EBM) to address two challenges in the science of sustainable management of ecosystems. First, we generalize natural capital theory to approximate realized shadow prices for multiple interacting natural capital stocks (species) making up an ecosystem. These prices enable ecosystem components to be better included in wealth-based sustainability measures. We show that ecosystems are best envisioned as portfolios of assets, where the portfolio’s performance depends on the performance of the underlying assets influenced by their interactions. Second, changes in ecosystem wealth provide an attractive headline index for EBM, regardless of whether ecosystem wealth is ultimately included in a broader wealth index. We apply our approach to the Baltic Sea ecosystem, focusing on the interacting community of three commercially important fish species: cod, herring, and sprat. Our results incorporate supporting services embodied in the shadow price of a species through its trophic interactions. Prey fish have greater shadow prices than expected based on market value, and predatory fish have lower shadow prices than expected based on market value. These results are because correctly measured shadow prices reflect interdependence and limits to substitution. We project that ecosystem wealth in the Baltic Sea fishery ecosystem generally increases conditional on the EBM-inspired multispecies maximum sustainable yield management beginning in 2017, whereas continuing the current single-species management generally results in declining wealth. PMID:28588145

Ecosystem-based management and the wealth of ecosystems.

Science.gov (United States)

Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K; Fenichel, Eli P

2017-06-20

We merge inclusive wealth theory with ecosystem-based management (EBM) to address two challenges in the science of sustainable management of ecosystems. First, we generalize natural capital theory to approximate realized shadow prices for multiple interacting natural capital stocks (species) making up an ecosystem. These prices enable ecosystem components to be better included in wealth-based sustainability measures. We show that ecosystems are best envisioned as portfolios of assets, where the portfolio's performance depends on the performance of the underlying assets influenced by their interactions. Second, changes in ecosystem wealth provide an attractive headline index for EBM, regardless of whether ecosystem wealth is ultimately included in a broader wealth index. We apply our approach to the Baltic Sea ecosystem, focusing on the interacting community of three commercially important fish species: cod, herring, and sprat. Our results incorporate supporting services embodied in the shadow price of a species through its trophic interactions. Prey fish have greater shadow prices than expected based on market value, and predatory fish have lower shadow prices than expected based on market value. These results are because correctly measured shadow prices reflect interdependence and limits to substitution. We project that ecosystem wealth in the Baltic Sea fishery ecosystem generally increases conditional on the EBM-inspired multispecies maximum sustainable yield management beginning in 2017, whereas continuing the current single-species management generally results in declining wealth.

Economic Valuation of Ecosystem Goods and Services in a Melting Arctic

Science.gov (United States)

O'Garra, T.

2014-12-01

The Arctic region is composed of unique ecosystems that provide a range of goods and services to local and global populations. However, Arctic sea-ice is melting at an unprecedented rate, threatening many of these ecosystems and the services they provide. Yet as the ice melts and certain goods and services are lost, other resources such as oil and minerals will become accessible. The question is: how do the losses compare with the opportunities? And how are the losses and potential gains likely to be distributed? To address these questions, this study provides a preliminary assessment of the quantity, distribution and economic value of the ecosystem services (ES) provided by Arctic ecosystems, both now and in the future given a scenario of sure climate change. Using biophysical and economic data from existing studies (and some primary data), preliminary estimates indicate that the Arctic currently provides 357m/yr (in 2014 US) in subsistence hunting value to local communities, of which reindeer/caribou comprise 83%. Reindeer herding provides 110m/yr to Arctic communities. Interestingly, 'non-use (existence/cultural) values' associated with Arctic species are very high at 11bn/yr to members of Arctic states. The Arctic also provides ES that accrue to the global community: oil resources (North Slope; 5bn profits in 2013), commercial fisheries ( 515mn/yr) and most importantly, climate regulation services. Recent models (Whiteman; Euskirchen) estimate that the loss of climate regulation services provided by Arctic ice will cost 200 - 500bn/yr, a value which dwarfs all others. Assuming no change in atmospheric temperature compared to 2014, the net present value of the Arctic by 2050 (1.4% discount rate) comes to over $9 trillion. However, given Wang and Overland (2009) predictions of ice-free summers by 2037, we expect many of these benefits will be lost. For example, it is fairly well-established that endemic species, such as polar bears, will decline with sea-ice melt

Ecosystem services, land-cover change, and stakeholders: finding a sustainable foothold for a semiarid biodiversity hotspot

CSIR Research Space (South Africa)

Reyers, B

2009-01-01

Full Text Available -cover change involves changes in the human management of ecosystems (e.g., settlement, cultivation, and grazing) that alter the biogeochemical cycles, climate, and hydrology of an ecosystem. It also drives biodiversity loss through habitat fragmentation... and Frank 2006, Li et al. 2007). Case studies and simulations of land-cover change have also been used to examine the effects on single ecosystem services or processes (e.g., nitrogen levels (Turner et al. 2003), pollination (Priess et al. 2007...

Modelling the dynamic interactions between food production and ecosystem services

NARCIS (Netherlands)

Duku, C.

2017-01-01

Given the high levels of food insecurity and the loss of vital ecosystem services associated with deforestation, countries in sub-Saharan Africa (SSA) face a major dilemma. How can they produce enough food in a changing climate to feed an increasing population while protecting natural forests and

Ecosystem consequences of tree monodominance for nitrogen cycling in lowland tropical forest.

Science.gov (United States)

Brookshire, E N Jack; Thomas, Steven A

2013-01-01

Understanding how plant functional traits shape nutrient limitation and cycling on land is a major challenge in ecology. This is especially true for lowland forest ecosystems of the tropics which can be taxonomically and functionally diverse and rich in bioavailable nitrogen (N). In many tropical regions, however, diverse forests occur side-by-side with monodominant forest (one species >60% of canopy); the long-term biogeochemical consequences of tree monodominance are unclear. Particularly uncertain is whether the monodominant plant-soil system modifies nutrient balance at the ecosystem level. Here, we use chemical and stable isotope techniques to examine N cycling in old-growth Mora excelsa and diverse watershed rainforests on the island of Trinidad. Across 26 small watershed forests and 4 years, we show that Mora monodominance reduces bioavailable nitrate in the plant-soil system to exceedingly low levels which, in turn, results in small hydrologic and gaseous N losses at the watershed-level relative to adjacent N-rich diverse forests. Bioavailable N in soils and streams remained low and remarkably stable through time in Mora forests; N levels in diverse forests, on the other hand, showed high sensitivity to seasonal and inter-annual rainfall variation. Total mineral N losses from diverse forests exceeded inputs from atmospheric deposition, consistent with N saturation, while losses from Mora forests did not, suggesting N limitation. Our measures suggest that this difference cannot be explained by environmental factors but instead by low internal production and efficient retention of bioavailable N in the Mora plant-soil system. These results demonstrate ecosystem-level consequences of a tree species on the N cycle opposite to cases where trees enhance ecosystem N supply via N2 fixation and suggest that, over time, Mora monodominance may generate progressive N draw-down in the plant-soil system.

Ecosystem consequences of tree monodominance for nitrogen cycling in lowland tropical forest.

Directory of Open Access Journals (Sweden)

E N Jack Brookshire

Full Text Available Understanding how plant functional traits shape nutrient limitation and cycling on land is a major challenge in ecology. This is especially true for lowland forest ecosystems of the tropics which can be taxonomically and functionally diverse and rich in bioavailable nitrogen (N. In many tropical regions, however, diverse forests occur side-by-side with monodominant forest (one species >60% of canopy; the long-term biogeochemical consequences of tree monodominance are unclear. Particularly uncertain is whether the monodominant plant-soil system modifies nutrient balance at the ecosystem level. Here, we use chemical and stable isotope techniques to examine N cycling in old-growth Mora excelsa and diverse watershed rainforests on the island of Trinidad. Across 26 small watershed forests and 4 years, we show that Mora monodominance reduces bioavailable nitrate in the plant-soil system to exceedingly low levels which, in turn, results in small hydrologic and gaseous N losses at the watershed-level relative to adjacent N-rich diverse forests. Bioavailable N in soils and streams remained low and remarkably stable through time in Mora forests; N levels in diverse forests, on the other hand, showed high sensitivity to seasonal and inter-annual rainfall variation. Total mineral N losses from diverse forests exceeded inputs from atmospheric deposition, consistent with N saturation, while losses from Mora forests did not, suggesting N limitation. Our measures suggest that this difference cannot be explained by environmental factors but instead by low internal production and efficient retention of bioavailable N in the Mora plant-soil system. These results demonstrate ecosystem-level consequences of a tree species on the N cycle opposite to cases where trees enhance ecosystem N supply via N2 fixation and suggest that, over time, Mora monodominance may generate progressive N draw-down in the plant-soil system.

Tradeoffs between income, biodiversity, and ecosystem functioning during tropical rainforest conversion and agroforestry intensification.

Science.gov (United States)

Steffan-Dewenter, Ingolf; Kessler, Michael; Barkmann, Jan; Bos, Merijn M; Buchori, Damayanti; Erasmi, Stefan; Faust, Heiko; Gerold, Gerhard; Glenk, Klaus; Gradstein, S Robbert; Guhardja, Edi; Harteveld, Marieke; Hertel, Dietrich; Höhn, Patrick; Kappas, Martin; Köhler, Stefan; Leuschner, Christoph; Maertens, Miet; Marggraf, Rainer; Migge-Kleian, Sonja; Mogea, Johanis; Pitopang, Ramadhaniel; Schaefer, Matthias; Schwarze, Stefan; Sporn, Simone G; Steingrebe, Andrea; Tjitrosoedirdjo, Sri S; Tjitrosoemito, Soekisman; Twele, André; Weber, Robert; Woltmann, Lars; Zeller, Manfred; Tscharntke, Teja

2007-03-20

Losses of biodiversity and ecosystem functioning due to rainforest destruction and agricultural intensification are prime concerns for science and society alike. Potentially, ecosystems show nonlinear responses to land-use intensification that would open management options with limited ecological losses but satisfying economic gains. However, multidisciplinary studies to quantify ecological losses and socioeconomic tradeoffs under different management options are rare. Here, we evaluate opposing land use strategies in cacao agroforestry in Sulawesi, Indonesia, by using data on species richness of nine plant and animal taxa, six related ecosystem functions, and on socioeconomic drivers of agroforestry expansion. Expansion of cacao cultivation by 230% in the last two decades was triggered not only by economic market mechanisms, but also by rarely considered cultural factors. Transformation from near-primary forest to agroforestry had little effect on overall species richness, but reduced plant biomass and carbon storage by approximately 75% and species richness of forest-using species by approximately 60%. In contrast, increased land use intensity in cacao agroforestry, coupled with a reduction in shade tree cover from 80% to 40%, caused only minor quantitative changes in biodiversity and maintained high levels of ecosystem functioning while doubling farmers' net income. However, unshaded systems further increased income by approximately 40%, implying that current economic incentives and cultural preferences for new intensification practices put shaded systems at risk. We conclude that low-shade agroforestry provides the best available compromise between economic forces and ecological needs. Certification schemes for shade-grown crops may provide a market-based mechanism to slow down current intensification trends.

Loss Distribution Approach (LDA: metodología actuarial aplicada al riesgo operacional Loss Distribution Approach (LDA: actuarial methodology apply to operational risk

Directory of Open Access Journals (Sweden)

Luis Ceferino Franco Arbeláez

2008-07-01

Full Text Available Este artículo es resultado de un proyecto de investigación sobre la gestión integral del riesgo operacional promovido por la Vicerrectoria de Investigaciones de la Universidad de Medellín, y cofinanciado por una firma comisionista. Se presenta una aplicación del modelo LDA, el cual se basa en la recopilación de los datos de pérdidas históricas (frecuencia y severidad, que se registran internamente en las organizaciones. Dichos datos pueden ser complementados con datos externos. Estas pérdidas son clasificadas en una matriz que relaciona las líneas de negocio de la organización y los eventos operacionales de pérdida, a partir de la cual se calcula la carga de capital. La aplicación se desarrolló para una entidad financiera. El artículo está organizado de la siguiente forma: la primera sección es introductoria al tema. En la segunda parte se presenta formalmente el modelo LDA; luego se realiza una aplicación, y en la cuarta sección se presentan algunas conclusiones.This paper is the result of a research project on integrated management of operational risk, promoted by Universidad de Medellin Research Vice-Principal's Office and co-financed by a financial company. It presents an application of the LDA model, which is based on data collection of historical losses (frequency and severity, which are recorded internally in organizations. Such data can be supplemented with external data. These losses are classified in a matrix that relates business lines of the organization and operational loss events, from which capital charge is estimated. The application was developed for a financial institution. The paper is organized as follows: The first section is introductory to the subject. The second part formally presents a LDA model; then an application is made, and in the fourth part some conclusions are presented.

Surrogate runner model for draft tube losses computation within a wide range of operating points

International Nuclear Information System (INIS)

Susan-Resiga, R; Ciocan, T; Muntean, S; De Colombel, T; Leroy, P

2014-01-01

We introduce a quasi two-dimensional (Q2D) methodology for assessing the swirling flow exiting the runner of hydraulic turbines at arbitrary operating points, within a wide operating range. The Q2D model does not need actual runner computations, and as a result it represents a surrogate runner model for a-priori assessment of the swirling flow ingested by the draft tube. The axial, radial and circumferential velocity components are computed on a conical section located immediately downstream the runner blades trailing edge, then used as inlet conditions for regular draft tube computations. The main advantage of our model is that it allows the determination of the draft tube losses within the intended turbine operating range in the early design stages of a new or refurbished runner, thus providing a robust and systematic methodology to meet the optimal requirements for the flow at the runner outlet

Neuronal Store-Operated Calcium Entry and Mushroom Spine Loss in Amyloid Precursor Protein Knock-In Mouse Model of Alzheimer's Disease.

Science.gov (United States)

Zhang, Hua; Wu, Lili; Pchitskaya, Ekaterina; Zakharova, Olga; Saito, Takashi; Saido, Takaomi; Bezprozvanny, Ilya

2015-09-30

Alzheimer's disease (AD) is the most common reason for elderly dementia in the world. We proposed that memory loss in AD is related to destabilization of mushroom postsynaptic spines involved in long-term memory storage. We demonstrated previously that stromal interaction molecule 2 (STIM2)-regulated neuronal store-operated calcium entry (nSOC) in postsynaptic spines play a key role in stability of mushroom spines by maintaining activity of synaptic Ca(2+)/calmodulin kinase II (CaMKII). Furthermore, we demonstrated previously that the STIM2-nSOC-CaMKII pathway is downregulated in presenilin 1 M146V knock-in (PS1-M146V KI) mouse model of AD, leading to loss of hippocampal mushroom spines in this model. In the present study, we demonstrate that hippocampal mushroom postsynaptic spines are also lost in amyloid precursor protein knock-in (APPKI) mouse model of AD. We demonstrated that loss of mushroom spines occurs as a result of accumulation of extracellular β-amyloid 42 in APPKI culture media. Our results indicate that extracellular Aβ42 acts by overactivating mGluR5 receptor in APPKI neurons, leading to elevated Ca(2+) levels in endoplasmic reticulum, compensatory downregulation of STIM2 expression, impaired synaptic nSOC, and reduced CaMKII activity. Pharmacological inhibition of mGluR5 or overexpression of STIM2 rescued synaptic nSOC and prevented mushroom spine loss in APPKI hippocampal neurons. Our results indicate that downregulation of synaptic STIM2-nSOC-CaMKII pathway causes loss of mushroom synaptic spines in both presenilin and APPKI mouse models of AD. We propose that modulators/activators of this pathway may have a potential therapeutic value for treatment of memory loss in AD. Significance statement: A direct connection between amyloid-induced synaptic mushroom spine loss and neuronal store-operated calcium entry pathway is shown. These results provide strong support for the calcium hypothesis of neurodegeneration and further validate the synaptic

Ecosystem development after mangrove creation: plant-soil change across a twenty-year chronosequence in Tampa Bay, FL

Science.gov (United States)

On a global scale, the loss of mangroves has been high (~1-2% loss per year in recent decades). Recognizing the important ecosystem services supported by mangroves, restoration and creation efforts are increasingly proposed as mechanisms to replace those services lost after mangr...

Generic evaluation of feedwater transients and small break loss-of-coolant accidents in combustion engineering designed operating plants

International Nuclear Information System (INIS)

1980-01-01

The purpose of this report is to summarize the results of a generic evaluation of feedwater transients, small break loss-of-coolant accidents (LOCAs), and other TMI-2-related events in the Combustion Engineering (CE)-designed operating plants and to establish or confirm the bases for their continued operation. The results of this evaluation are presented in this report in the form of a set of findings and recommendations in each of the principal review areas

Quantifying the Benefit of Early Climate Change Mitigation in Avoiding Biodiversity Loss

Science.gov (United States)

Warren, R.; Vanderwal, J.; Price, J.; Welbergen, J.; Atkinson, I. M.; Ramirez-Villegas, J.; Osborn, T.; Shoo, L.; Jarvis, A.; Williams, S.; Lowe, J. A.

2014-12-01

Quantitative simulations of the global-scale benefits of climate change mitigation in avoiding biodiversity loss are presented. Previous studies have projected widespread global and regional impacts of climate change on biodiversity. However, these have focused on analysis of business-as-usual scenarios, with no explicit mitigation policy included. This study finds that early, stringent mitigation would avoid a large proportion of the impacts of climate change induced biodiversity loss projected for the 2080s. Furthermore, despite the large number of studies addressing extinction risks in particular species groups, few studies have explored the issue of potential range loss in common and widespread species. Our study is a comprehensive global scale analysis of 48,786 common and widespread species. We show that without climate change mitigation, 57+/-6% of the plants and 34+/-7% of the animals studied are likely to lose over 50% of their present climatic range by the 2080s. This estimate incorporates realistic, taxon-specific dispersal rates. With stringent mitigation, in which emissions peak in 2016 and are reduced by 5% annually thereafter, these losses are reduced by 60%. Furthermore, with stringent mitigation, global temperature rises more slowly, allowing an additional three decades for biodiversity to adapt to a temperature rise of 2C above pre-industrial levels. The work also shows that even with mitigation not all the impacts can now be avoided, and ecosystems and biodiversity generally has a very limited capacity to adapt. Delay in mitigation substantially reduces the percentage of impacts that can be avoided, for example if emissions do not peak until 2030, the percentage of losses that can be avoided declines to 40%. Since even small declines in common and widespread species can disrupt ecosystem function and services, these results indicate that without mitigation, globally widespread losses in ecosystem service provision are to be expected.

Application of artificial intelligence to risk analysis for forested ecosystems

Science.gov (United States)

Daniel L. Schmoldt

2001-01-01

Forest ecosystems are subject to a variety of natural and anthropogenic disturbances that extract a penalty from human population values. Such value losses (undesirable effects) combined with their likelihoods of occurrence constitute risk. Assessment or prediction of risk for various events is an important aid to forest management. Artificial intelligence (AI)...

Ecosystem model of the entire Beaufort Sea marine ecosystem: a tool for assessing food-web structure and ecosystem changes from 1970 to 2014

Science.gov (United States)

Suprenand, P. M.; Hoover, C.

2016-02-01

The Beaufort Sea coastal-marine ecosystem is approximately a 476,000 km2 area in the Arctic Ocean, which extends from -112.5 to -158° longitude to 67.5 to 75° latitude. Within this Arctic Ocean area the United States (Alaskan) indigenous communities of Barrow, Kaktovik, and Nuiqsut, and the Canadian (Northwest Territories) indigenous communities of Aklavik, Inuvik, Tuktoyaktuk, Paulatuk, Ulukhaktok, and Sachs Harbour, subsist by harvesting marine mammals, fish, and invertebrates from the Beaufort Sea to provide the majority of their community foods annually. The ecosystem in which the indigenous communities harvest is considered a polar habitat that includes many specialized species, such as polar bears that rely on sea-ice for foraging activities and denning, or ice algae that are attached to the cryosphere. However, the polar habitat has been experiencing a diminishing sea-ice extent, age, and seasonal duration, with concomitant increases in sea surface temperatures (SSTs), since the 1970s. Changes in sea-ice and SST have consequences to the Beaufort Sea coastal-marine ecosystem, which includes animal habitat losses, alterations to trophodynamics, and impacts to subsistence community harvesting. The present study was aimed at capturing trophodynamic changes in the Beaufort Sea coastal-marine ecosystem from 1970 to 2014 using a fitted spatial-temporal model (Ecopath with Ecosim and Ecospace) that utilizes forcing and mediation functions to describe animal/trophodynamic relationships with sea-ice and sea surface temperature, as well as individual community harvesting efforts. Model outputs reveals similar trends in animals population changes (e.g., increasing bowhead whale stock), changes in apex predator diets (e.g., polar bears eating less ringed seal), and changes in animal distributions (e.g., polar bears remaining closer to land over time). The Beaufort Sea model is a dynamic tool for Arctic Ocean natural resource management in the years to come.

Climate change on arctic environment, ecosystem services and society (CLICHE)

Science.gov (United States)

Weckström, J.; Korhola, A.; Väliranta, M.; Seppä, H.; Luoto, M.; Tuittila, E.-S.; Leppäranta, M.; Kahilainen, K.; Saarinen, J.; Heikkinen, H.

2012-04-01

The predicted climate warming has raised many questions and concerns about its impacts on the environment and society. As a respond to the need of holistic studies comprising both of these areas, The Academy of Finland launched The Finnish Research Programme on Climate Change (FICCA 2011-2014) in spring 2010 with the main aim to focus on the interaction between the environment and society. Ultimately 11 national consortium projects were funded (total budget 12 million EUR). Here we shortly present the main objectives of the largest consortium project "Climate change on arctic environment, ecosystem services and society" (CLICHE). The CLICHE consortium comprises eight interrelated work packages (treeline, diversity, peatlands, snow, lakes, fish, tourism, and traditional livelihoods), each led by a prominent research group and a team leader. The research consortium has three main overall objectives: 1) Investigate, map and model the past, present and future climate change-induced changes in central ecosystems of the European Arctic with unprecedented precision 2) Deepen our understanding of the basic principles of ecosystem and social resilience and dynamics; identify key taxa, structures or processes that clearly indicate impending or realised global change through their loss, occurrence or behaviour, using analogues from the past (e.g. Holocene Thermal Maximum, Medieval Warm Period), experiments, observations and models 3) Develop adaptation and mitigation strategies to minimize the adverse effects of climate change on local communities, traditional livelihoods, fisheries, and tourism industry, and promote sustainable development of local community structures and enhance the quality of life of local human populations. As the project has started only recently no final results are available yet. However, the fieldwork as well as the co-operation between the research teams has thus far been very successful. Thus, the expectations for the final outcome of the project

Bitumen and biocarbon : land use conversions and loss of biological carbon due to bitumen operations in the Boreal forests of Alberta, Canada

Energy Technology Data Exchange (ETDEWEB)

Lee, P.; Cheng, R.

2009-07-01

This paper discussed land use changes, biological carbon content, and the potential greenhouse gas (GHG) emissions caused by existing and future oil sands mining and in situ extraction in Alberta, Canada. The study focused on estimating changes to the natural ecosystems caused by open pit mines, tailings ponds, mine waste, overburden piles and other major infrastructure put in place by surface mining activities. The study showed that a total of 488,968 ha of peatlands, mineral wetlands, and upland forest ecosystems have undergone changes as a result of oil sands mining activities. Natural ecosystems that have undergone land use changes as a result of exploration wells, production wells, access roads, pipelines, and other infrastructure related to existing and potential in situ operations totalled 1,124,919 ha. If all 578.9 megatonnes of carbon produced by oil sands mines in Alberta were emitted, it is likely that 873.4 megatonnes of carbon dioxide (CO{sub 2}) would be released into the atmosphere. The average annual release of CO{sub 2} was estimated at 8.7 megatonnes over a 100 year period. 59 refs., 11 tabs., 12 figs.

Assessment of the impact of increased solar ultraviolet radiation upon marine ecosystems

Science.gov (United States)

Worrest, R. C.; Vandyke, H.

1978-01-01

Reduction of the earth's ozone layer, with a resultant increase in transmission of solar ultraviolet radiation in the 290 to 320nm waveband (UV-B), via space shuttle operations through the stratosphere is considered. It is shown that simulated solar ultraviolet radiation can, under experimental conditions, detrimentally affect the marine organisms that form the base of the food web of oceanic and estuarine ecosystems. Whether a small increase in biologically harmful ultraviolet radiation might overwhelm these mechanisms and produce changes that will have damaging consequences to the biosphere is discussed. The potential for irreversible damage to the productivity, structure and/or functioning of a model estuarine ecosystem by increased UV-B radiation and whether these ecosystems are highly stable or amenable to adaptive change is studied. Data are provided to assess the potential impact upon marine ecosystems if space shuttle operations contribute to a reduction of the stratospheric ozone layer and the sensitivity of key community components to increased UV-B radiation is examined.

Rainfall changes affect the algae dominance in tank bromeliad ecosystems

Science.gov (United States)

Pires, Aliny Patricia Flauzino; Leal, Juliana da Silva; Peeters, Edwin T. H. M.

2017-01-01

Climate change and biodiversity loss have been reported as major disturbances in the biosphere which can trigger changes in the structure and functioning of natural ecosystems. Nonetheless, empirical studies demonstrating how both factors interact to affect shifts in aquatic ecosystems are still unexplored. Here, we experimentally test how changes in rainfall distribution and litter diversity affect the occurrence of the algae-dominated condition in tank bromeliad ecosystems. Tank bromeliads are miniature aquatic ecosystems shaped by the rainwater and allochthonous detritus accumulated in the bases of their leaves. Here, we demonstrated that changes in the rainfall distribution were able to reduce the chlorophyll-a concentration in the water of bromeliad tanks affecting significantly the occurrence of algae-dominated conditions. On the other hand, litter diversity did not affect the algae dominance irrespective to the rainfall scenario. We suggest that rainfall changes may compromise important self-reinforcing mechanisms responsible for maintaining high levels of algae on tank bromeliads ecosystems. We summarized these results into a theoretical model which suggests that tank bromeliads may show two different regimes, determined by the bromeliad ability in taking up nutrients from the water and by the total amount of light entering the tank. We concluded that predicted climate changes might promote regime shifts in tropical aquatic ecosystems by shaping their structure and the relative importance of other regulating factors. PMID:28422988

Operation of an enclosed aquatic ecosystem in the Shenzhou-8 mission

Science.gov (United States)

Li, Xiaoyan; Richter, Peter R.; Hao, Zongjie; An, Yanjun; Wang, Gaohong; Li, Dunhai; Liu, Yongding; Strauch, Sebastian M.; Schuster, Martin; Haag, Ferdinand W.; Lebert, Michael

2017-05-01

Long- term spaceflight needs reliable Biological life support systems (BLSS) to supply astronauts with enough food, fresh air and recycle wasters, but the knowledge about the operation pattern and controlling strategy is rear. For this purpose, a miniaturized enclosed aquatic ecosystem was developed and flown on the Chinese spaceship Shenzhou-8. The system with a total volume of about 60 mL was separated into two chambers by means of a gas transparent membrane. The lower chamber was inoculated with Euglena gracilis cells, and the upper chamber was cultured with Chlorella cells and three snails. After 17.5 days flight, the samples were analyzed. It was found that all snails in the ground module (GM) were alive, while in the flight module (FM) only one snail survived. The total cell numbers, assimilation of nutrients like nitrogen and phosphorus, soluble proteins and carbohydrate contents showed a decrease in FM than in GM. The correlation analysis showed upper chambers of both FM and GM had the same positive and negative correlation factors, while differential correlation was found in lower chambers. These results suggested primary productivity in the enclosed system decreased in microgravity, accompanied with nutrients assimilation. The FM chamber endured lacking of domination species to sustain the system development and GM chamber endured richness in population abundance. These results implied photosynthesis intensity should be reduced to keep the system healthy. More Chlorella but less Euglena might be a useful strategy to sustain system stability. It is the first systematic analysis of enclosed systems in microgravity.

Response diversity determines the resilience of ecosystems to environmental change.

Science.gov (United States)

Mori, Akira S; Furukawa, Takuya; Sasaki, Takehiro

2013-05-01

A growing body of evidence highlights the importance of biodiversity for ecosystem stability and the maintenance of optimal ecosystem functionality. Conservation measures are thus essential to safeguard the ecosystem services that biodiversity provides and human society needs. Current anthropogenic threats may lead to detrimental (and perhaps irreversible) ecosystem degradation, providing strong motivation to evaluate the response of ecological communities to various anthropogenic pressures. In particular, ecosystem functions that sustain key ecosystem services should be identified and prioritized for conservation action. Traditional diversity measures (e.g. 'species richness') may not adequately capture the aspects of biodiversity most relevant to ecosystem stability and functionality, but several new concepts may be more appropriate. These include 'response diversity', describing the variation of responses to environmental change among species of a particular community. Response diversity may also be a key determinant of ecosystem resilience in the face of anthropogenic pressures and environmental uncertainty. However, current understanding of response diversity is poor, and we see an urgent need to disentangle the conceptual strands that pervade studies of the relationship between biodiversity and ecosystem functioning. Our review clarifies the links between response diversity and the maintenance of ecosystem functionality by focusing on the insurance hypothesis of biodiversity and the concept of functional redundancy. We provide a conceptual model to describe how loss of response diversity may cause ecosystem degradation through decreased ecosystem resilience. We explicitly explain how response diversity contributes to functional compensation and to spatio-temporal complementarity among species, leading to long-term maintenance of ecosystem multifunctionality. Recent quantitative studies suggest that traditional diversity measures may often be uncoupled from

Remote Sensing of Mangrove Ecosystems: A Review

Directory of Open Access Journals (Sweden)

Stefan Dech

2011-04-01

Full Text Available Mangrove ecosystems dominate the coastal wetlands of tropical and subtropical regions throughout the world. They provide various ecological and economical ecosystem services contributing to coastal erosion protection, water filtration, provision of areas for fish and shrimp breeding, provision of building material and medicinal ingredients, and the attraction of tourists, amongst many other factors. At the same time, mangroves belong to the most threatened and vulnerable ecosystems worldwide and experienced a dramatic decline during the last half century. International programs, such as the Ramsar Convention on Wetlands or the Kyoto Protocol, underscore the importance of immediate protection measures and conservation activities to prevent the further loss of mangroves. In this context, remote sensing is the tool of choice to provide spatio-temporal information on mangrove ecosystem distribution, species differentiation, health status, and ongoing changes of mangrove populations. Such studies can be based on various sensors, ranging from aerial photography to high- and medium-resolution optical imagery and from hyperspectral data to active microwave (SAR data. Remote-sensing techniques have demonstrated a high potential to detect, identify, map, and monitor mangrove conditions and changes during the last two decades, which is reflected by the large number of scientific papers published on this topic. To our knowledge, a recent review paper on the remote sensing of mangroves does not exist, although mangrove ecosystems have become the focus of attention in the context of current climate change and discussions of the services provided by these ecosystems. Also, climate change-related remote-sensing studies in coastal zones have increased drastically in recent years. The aim of this review paper is to provide a comprehensive overview and sound summary of all of the work undertaken, addressing the variety of remotely sensed data applied for mangrove

Simulation study on beam loss in the alpha bucket regime during SIS-100 proton operation

Science.gov (United States)

Sorge, S.

2018-02-01

Crossing the transition energy γt in synchrotrons for high intensity proton beams requires well tuned jump schemes and is usually accompanied by longitudinal emittance growth. In order to avoid γt crossing during proton operation in the projected SIS-100 synchrotron special high-γt lattice settings have been developed, in order to keep γt above the beam extraction energy. A further advantage of this scheme is the formation of alpha buckets which naturally lead to short proton bunches, required for the foreseen production and storage of antiprotons for the FAIR facility. Special attention is turned on the imperfections of the superconducting SIS-100 magnets because together with the high-γt lattice settings, they could potentially lead to enhanced beam loss. The aim of the present work is to estimate the beam loss by means of particle tracking simulations.

Mobility on Demand Operational Concept Report.

Science.gov (United States)

2017-09-10

This operational concept report provides an overview of the Mobility on Demand (MOD) concept and its evolution, description of the MOD ecosystem in a supply and demand framework, and its stakeholders and enablers. Leveraging the MOD ecosystem framewo...

Arctic ecosystem responses to a warming climate

DEFF Research Database (Denmark)

Mortensen, Lars O.

sheet, loss of multiannual sea-ice and significant advances in snowmelt days. The biotic components of the arctic ecosystem have also been affected by the rapid changes in climate, for instance resulting in the collapse of the collared lemming cycle, advances in spring flowering and changes in the intra...... biotic interactions. Hence, through the use of up-to-date multivariate statistical tools, this Ph.D. study has been concerned with analyzing how the observed rapid climate changes are affecting the arctic ecosystems. The primary tool has been the implementation of structural equation modeling (SEM) which....... Additionally, the study demonstrated that climate effects had distinct direct and indirect effects on different trophic levels, indicating cascading effects of climate through the trophic system. Results suggest that the Arctic is being significantly affected by the observed climate changes and depending...

Impacts of exotic forest pathogens on Mediterranean ecosystems: Four case studies

Science.gov (United States)

Matteo Garbelotto; Marco Pautasso

2011-01-01

Mediterranean ecosystems are hotspots of biodiversity. Because of a coincidence of high species richness and human presence, Mediterranean biodiversity is particularly threatened by processes such as habitat degradation, fragmentation and loss, pollution, climate change and introduction of invasive species. Invasive tree pathogens are among the problematic exotic...

Social science constructs in ecosystem assessments: revisiting community capacity and community resiliency.

Science.gov (United States)

Ellen M. Donoghue; Victoria E. Sturtevant

2007-01-01

This article explores the development of sociological constructs in community assessment components of large-scale ecosystem assessments. We compare the conceptual and operational development of the constructs of community capacity and community resiliency used in three community assessments in the western United States: the Forest Ecosystem Management Assessment Team...

Dual role of lignin in plant litter decomposition in terrestrial ecosystems.

Science.gov (United States)

Austin, Amy T; Ballaré, Carlos L

2010-03-09

Plant litter decomposition is a critical step in the formation of soil organic matter, the mineralization of organic nutrients, and the carbon balance in terrestrial ecosystems. Biotic decomposition in mesic ecosystems is generally negatively correlated with the concentration of lignin, a group of complex aromatic polymers present in plant cell walls that is recalcitrant to enzymatic degradation and serves as a structural barrier impeding microbial access to labile carbon compounds. Although photochemical mineralization of carbon has recently been shown to be important in semiarid ecosystems, litter chemistry controls on photodegradative losses are not understood. We evaluated the importance of litter chemistry on photodegradation of grass litter and cellulose substrates with varying levels of lignin [cellulose-lignin (CL) substrates] under field conditions. Using wavelength-specific light attenuation filters, we found that light-driven mass loss was promoted by both UV and visible radiation. The spectral dependence of photodegradation correlated with the absorption spectrum of lignin but not of cellulose. Field incubations demonstrated that increasing lignin concentration reduced biotic decomposition, as expected, but linearly increased photodegradation. In addition, lignin content in CL substrates consistently decreased in photodegradative incubations. We conclude that lignin has a dual role affecting litter decomposition, depending on the dominant driver (biotic or abiotic) controlling carbon turnover. Under photodegradative conditions, lignin is preferentially degraded because it acts as an effective light-absorbing compound over a wide range of wavelengths. This mechanistic understanding of the role of lignin in plant litter decomposition will allow for more accurate predictions of carbon dynamics in terrestrial ecosystems.

Global consequences of afforestation and bioenergy cultivation on ecosystem service indicators

Science.gov (United States)

Krause, Andreas; Pugh, Thomas A. M.; Bayer, Anita D.; Doelman, Jonathan C.; Humpenöder, Florian; Anthoni, Peter; Olin, Stefan; Bodirsky, Benjamin L.; Popp, Alexander; Stehfest, Elke; Arneth, Almut

2017-11-01

Land management for carbon storage is discussed as being indispensable for climate change mitigation because of its large potential to remove carbon dioxide from the atmosphere, and to avoid further emissions from deforestation. However, the acceptance and feasibility of land-based mitigation projects depends on potential side effects on other important ecosystem functions and their services. Here, we use projections of future land use and land cover for different land-based mitigation options from two land-use models (IMAGE and MAgPIE) and evaluate their effects with a global dynamic vegetation model (LPJ-GUESS). In the land-use models, carbon removal was achieved either via growth of bioenergy crops combined with carbon capture and storage, via avoided deforestation and afforestation, or via a combination of both. We compare these scenarios to a reference scenario without land-based mitigation and analyse the LPJ-GUESS simulations with the aim of assessing synergies and trade-offs across a range of ecosystem service indicators: carbon storage, surface albedo, evapotranspiration, water runoff, crop production, nitrogen loss, and emissions of biogenic volatile organic compounds. In our mitigation simulations cumulative carbon storage by year 2099 ranged between 55 and 89 GtC. Other ecosystem service indicators were influenced heterogeneously both positively and negatively, with large variability across regions and land-use scenarios. Avoided deforestation and afforestation led to an increase in evapotranspiration and enhanced emissions of biogenic volatile organic compounds, and to a decrease in albedo, runoff, and nitrogen loss. Crop production could also decrease in the afforestation scenarios as a result of reduced crop area, especially for MAgPIE land-use patterns, if assumed increases in crop yields cannot be realized. Bioenergy-based climate change mitigation was projected to affect less area globally than in the forest expansion scenarios, and resulted in

CLIMOOR. Climate driven changes in the functioning of heath and moorland ecosystems

Energy Technology Data Exchange (ETDEWEB)

Beier, C. [ed.; Tietema, A.; Riis Nielsen, T.; Emmett, B.; Estiarte, M.; Penuelas, J.; Llorens Guash, L.; Williams, D.; Gordon, C.; Pugh, B.; Roda, F.; Gundersen, P.; Gorissen, A.

2000-01-01

Emission of green house gases, partly generated from human activities, reduces the loss of heat from the earth thereby potentially causing climate change. This change in climate has been predicted to result in a 1-3 deg. C increase in temperature with more vigorous rainstorms and prolonged drought periods in the coming 100 years. The consequence of such climatic changes for the terrestrial ecosystems are largely unknown. In order to improve our understanding of the ecosystem response to climate change and thereby to improve the basis for the international negotiations and political decisions to avoid or minimise climate change and its effects, a European research project CLIMOOR has been initiated. The project is a cross European research project involving 6 research groups from Denmark, the Netherlands, UK and Spain and is funded by EU and the participating institutions. The project investigates the potential effects of warming and drought on heath and moorland ecosystems at four European sites. The ecosystems are manipulated at field scale by reducing the heat loss at night by IR-reflective curtains and by removing the precipitation during a 2 month period in the summer. The effects of these manipulations on the plants and the soil are studied. This report describes the technique used to apply the climate change at field scale and presents some preliminary results after the first growing season. EU and the participating institutions fund CLIMOOR. (au)

The roles of productivity and ecosystem size in determining food chain length in tropical terrestrial ecosystems.

Science.gov (United States)

Young, Hillary S; McCauley, Douglas J; Dunbar, Robert B; Hutson, Michael S; Ter-Kuile, Ana Miller; Dirzo, Rodolfo

2013-03-01

Many different drivers, including productivity, ecosystem size, and disturbance, have been considered to explain natural variation in the length of food chains. Much remains unknown about the role of these various drivers in determining food chain length, and particularly about the mechanisms by which they may operate in terrestrial ecosystems, which have quite different ecological constraints than aquatic environments, where most food chain length studies have been thus far conducted. In this study, we tested the relative importance of ecosystem size and productivity in influencing food chain length in a terrestrial setting. We determined that (1) there is no effect of ecosystem size or productive space on food chain length; (2) rather, food chain length increases strongly and linearly with productivity; and (3) the observed changes in food chain length are likely achieved through a combination of changes in predator size, predator behavior, and consumer diversity along gradients in productivity. These results lend new insight into the mechanisms by which productivity can drive changes in food chain length, point to potential for systematic differences in the drivers of food web structure between terrestrial and aquatic systems, and challenge us to consider how ecological context may control the drivers that shape food chain length.

Ecosystem Vulnerability Review: Proposal of an Interdisciplinary Ecosystem Assessment Approach

Science.gov (United States)

Weißhuhn, Peter; Müller, Felix; Wiggering, Hubert

2018-06-01

To safeguard the sustainable use of ecosystems and their services, early detection of potentially damaging changes in functional capabilities is needed. To support a proper ecosystem management, the analysis of an ecosystem's vulnerability provide information on its weaknesses as well as on its capacity to recover after suffering an impact. However, the application of the vulnerability concept to ecosystems is still an emerging topic. After providing background on the vulnerability concept, we summarize existing ecosystem vulnerability research on the basis of a systematic literature review with a special focus on ecosystem type, disciplinary background, and more detailed definition of the ecosystem vulnerability components. Using the Web of ScienceTM Core Collection, we overviewed the literature from 1991 onwards but used the 5 years from 2011 to 2015 for an in-depth analysis, including 129 articles. We found that ecosystem vulnerability analysis has been applied most notably in conservation biology, climate change research, and ecological risk assessments, pinpointing a limited spreading across the environmental sciences. It occurred primarily within marine and freshwater ecosystems. To avoid confusion, we recommend using the unambiguous term ecosystem vulnerability rather than ecological, environmental, population, or community vulnerability. Further, common ground has been identified, on which to define the ecosystem vulnerability components exposure, sensitivity, and adaptive capacity. We propose a framework for ecosystem assessments that coherently connects the concepts of vulnerability, resilience, and adaptability as different ecosystem responses. A short outlook on the possible operationalization of the concept by ecosystem vulnerabilty indices, and a conclusion section complete the review.

Preface: Ecosystem services, ecosystem health and human communities

Science.gov (United States)

Plag, Hans-Peter

2018-04-01

This special issue contains a collection of manuscripts that were originally intended to be included in the special issue on "Physics and Economics of Ecosystem Services Flows" (Volume 101, guest editors H. Su, J. Dong and S. Nagarajan) and "Biogeochemical Processes in the Changing Wetland Environment" (Volume 103, guest editors J. Bai, L. Huang and H. Gao). All of them are addressing issues related to ecosystem services in different settings. Ecosystem services are of high value for both the ecosystems and human communities, and understanding the impacts of environmental processes and human activities on ecosystems is of fundamental importance for the preservation of these services.

The marine ecosystem services approach in a fisheries management perspective

DEFF Research Database (Denmark)

Pedersen, Søren Anker; Lassen, Hans; Frost, Hans Staby

that the concept of marine ecosystem services is not helpful for the two first mentioned types of analysis and that a cost-benefit analysis that is implied by the marine ecosystem services concept is inadequate for the third. We argue that the discussion needs to be divided into two: (1) finding the boundaries......This paper reviews the concepts of marine ecosystem services and their economic valuation in a European fisheries management perspective. We find that the concept is at best cumbersome for advising on how best to regulate fisheries even in an ecosystem context. We propose that operational fisheries...... management must consider three different types of analysis, the yield of and the effect of fishing on the commercial species, the effects of fishing on habitats and non-commercial species and finally an overall analysis of the combined impact of all human activities on the marine ecosystem. We find...

Nitrogen-limited mangrove ecosystems conserve N through dissimilatory nitrate reduction to ammonium.

Science.gov (United States)

Fernandes, Sheryl Oliveira; Bonin, Patricia C; Michotey, Valérie D; Garcia, Nicole; LokaBharathi, P A

2012-01-01

Earlier observations in mangrove sediments of Goa, India have shown denitrification to be a major pathway for N loss. However, percentage of total nitrate transformed through complete denitrification accounted for nitrate reduced. Here, we show that up to 99% of nitrate removal in mangrove sediments is routed through dissimilatory nitrate reduction to ammonium (DNRA). The DNRA process was 2x higher at the relatively pristine site Tuvem compared to the anthropogenically-influenced Divar mangrove ecosystem. In systems receiving low extraneous nutrient inputs, this mechanism effectively conserves and re-circulates N minimizing nutrient loss that would otherwise occur through denitrification. In a global context, the occurrence of DNRA in mangroves has important implications for maintaining N levels and sustaining ecosystem productivity. For the first time, this study also highlights the significance of DNRA in buffering the climate by modulating the production of the greenhouse gas nitrous oxide.

A decision support system for restoration planning of stream valley ecosystems

NARCIS (Netherlands)

Pieterse, N.M.; Verkroost, A.W.M.; Wassen, M.; Olde Venterink, H.; Kwakernaak, C.

2002-01-01

Despite efforts that have been put into conservation, there is a continuing loss of species and ecosystems in Western Europe. There is a growing awareness that restoration is an essential step to stop this tide. Unfortunately, there is lack of understanding about the multitude of functions and the

How lichens impact on terrestrial community and ecosystem properties.

Science.gov (United States)

Asplund, Johan; Wardle, David A

2017-08-01

Lichens occur in most terrestrial ecosystems; they are often present as minor contributors, but in some forests, drylands and tundras they can make up most of the ground layer biomass. As such, lichens dominate approximately 8% of the Earth's land surface. Despite their potential importance in driving ecosystem biogeochemistry, the influence of lichens on community processes and ecosystem functioning have attracted relatively little attention. Here, we review the role of lichens in terrestrial ecosystems and draw attention to the important, but often overlooked role of lichens as determinants of ecological processes. We start by assessing characteristics that vary among lichens and that may be important in determining their ecological role; these include their growth form, the types of photobionts that they contain, their key functional traits, their water-holding capacity, their colour, and the levels of secondary compounds in their thalli. We then assess how these differences among lichens influence their impacts on ecosystem and community processes. As such, we consider the consequences of these differences for determining the impacts of lichens on ecosystem nutrient inputs and fluxes, on the loss of mass and nutrients during lichen thallus decomposition, and on the role of lichenivorous invertebrates in moderating decomposition. We then consider how differences among lichens impact on their interactions with consumer organisms that utilize lichen thalli, and that range in size from microfauna (for which the primary role of lichens is habitat provision) to large mammals (for which lichens are primarily a food source). We then address how differences among lichens impact on plants, through for example increasing nutrient inputs and availability during primary succession, and serving as a filter for plant seedling establishment. Finally we identify areas in need of further work for better understanding the role of lichens in terrestrial ecosystems. These include

Nitrogen excess in North American ecosystems: Predisposing factors, ecosystem responses, and management strategies

Science.gov (United States)

Fenn, M.E.; Poth, M.A.; Aber, J.D.; Baron, Jill S.; Bormann, B.T.; Johnson, D.W.; Lemly, A.D.; McNulty, S.G.; Ryan, D.F.; Stottlemyer, R.

1998-01-01

Most forests in North America remain nitrogen limited, although recent studies have identified forested areas that exhibit symptoms of N excess, analogous to overfertilization of arable land. Nitrogen excess in watersheds is detrimental because of disruptions in plant/soil nutrient relations, increased soil acidification and aluminum mobility, increased emissions of nitrogenous greenhouse gases from soil, reduced methane consumption in soil, decreased water quality, toxic effects on freshwater biota, and eutrophication of coastal marine waters. Elevated nitrate (NO3/-) loss to groundwater or surface waters is the primary symptom of N excess. Additional symptoms include increasing N concentrations and higher N:nutrient ratios in foliage (i.e., N:Mg, N:P), foliar accumulation of amino acids or NO3/-, and low soil C:N ratios. Recent nitrogen-fertilization studies in New England and Europe provide preliminary evidence that some forests receiving chronic N inputs may decline in productivity and experience greater mortality. Long-term fertilization at Mount Ascutney, Vermont, suggests that declining and slow N-cycling coniferous stands may be replaced by fast-growing and fast N-cycling deciduous forests. Symptoms of N saturation are particularly severe in high-elevation, nonaggrading spruce-fir ecosystems in the Appalachian Mountains and in eastern hardwood watersheds at the Fernow Experimental Forest near Parsons, West Virginia. In the Los Angeles Air Basin, mixed conifer forests and chaparral watersheds with high smog exposure are N saturated and exhibit the highest streamwater NO3/- concentrations for wildlands in North America. High-elevation alpine watersheds in the Colorado Front Range and a deciduous forest in Ontario, Canada, are N saturated, although N deposition is moderate (~8 kg??ha-1??yr-1). In contrast, the Harvard Forest hardwood stand in Massachusetts has absorbed >900 kg N/ha during 8 yr of N amendment studies without significant NO3/- leaching

Diversity, Adaptability and Ecosystem Resilience

Science.gov (United States)

Keribin, Rozenn; Friend, Andrew

2013-04-01

Our ability to predict climate change and anticipate its impacts depends on Earth System Models (ESMs) and their ability to account for the high number of interacting components of the Earth System and to gauge both their influence on the climate and the feedbacks they induce. The land carbon cycle is a component of ESMs that is still poorly constrained. Since the 1990s dynamic global vegetation models (DGVMs) have become the main tool through which we understand the interactions between plant ecosystems and the climate. While DGVMs have made it clear the impacts of climate change on vegetation could be dramatic, predicting the dieback of rainforests and massive carbon losses from various ecosystems, they are highly variable both in their composition and their predictions. Their treatment of plant diversity and competition in particular vary widely and are based on highly-simplified relationships that do not account for the multiple levels of diversity and adaptability found in real plant ecosystems. The aim of this GREENCYCLES II project is to extend an individual-based DGVM to treat the diversity of physiologies found in plant communities and evaluate their effect if any on the ecosystem's transient dynamics and resilience. In the context of the InterSectoral Impacts Model Intercomparison Project (ISI-MIP), an initiative coordinated by a team at the Potsdam Institute for Climate Impact Research (PIK) that aims to provide fast-track global impact assessments for the IPCC's Fifth Assessment Report, we compare 6 vegetation models including 4 DGVMs under different climate change scenarios and analyse how the very different treatments of plant diversity and interactions from one model to the next affect the models' results. We then investigate a new, more mechanistic method of incorporating plant diversity into the DGVM "Hybrid" based on ecological tradeoffs mediated by plant traits and individual-based competition for light.

Life on the margin: genetic isolation and diversity loss in a peripheral marine ecosystem, the Baltic Sea.

Science.gov (United States)

Johannesson, Kerstin; André, Carl

2006-07-01

Marginal populations are often isolated and under extreme selection pressures resulting in anomalous genetics. Consequently, ecosystems that are geographically and ecologically marginal might have a large share of genetically atypical populations, in need of particular concern in management of these ecosystems. To test this prediction, we analysed genetic data from 29 species inhabiting the low saline Baltic Sea, a geographically and ecologically marginal ecosystem. On average Baltic populations had lost genetic diversity compared to Atlantic populations: a pattern unrelated to dispersal capacity, generation time of species and taxonomic group of organism, but strongly related to type of genetic marker (mitochondrial DNA loci had lost c. 50% diversity, and nuclear loci 10%). Analyses of genetic isolation by geographic distance revealed clinal patterns of differentiation between Baltic and Atlantic regions. For a majority of species, clines were sigmoid with a sharp slope around the Baltic Sea entrance, indicating impeded gene flows between Baltic and Atlantic populations. Some species showed signs of allele frequencies being perturbed at the edge of their distribution inside the Baltic Sea. Despite the short geological history of the Baltic Sea (8000 years), populations inhabiting the Baltic have evolved substantially different from Atlantic populations, probably as a consequence of isolation and bottlenecks, as well as selection on adaptive traits. In addition, the Baltic Sea also acts a refuge for unique evolutionary lineages. This marginal ecosystem is thus vulnerable but also exceedingly valuable, housing unique genes, genotypes and populations that constitute an important genetic resource for management and conservation.

Land use impact evaluation in life cycle assessment based on ecosystem thermodynamics

International Nuclear Information System (INIS)

Wagendorp, Tim; Gulinck, Hubert; Coppin, Pol; Muys, Bart

2006-01-01

Life Cycle Assessment (LCA) studies of products with a major part of their life cycle in biological production systems (i.e. forestry and agriculture) are often incomplete because the assessment of the land use impact is not operational. Most method proposals include the quality of the land in a descriptive way using rank scores for an arbitrarily selected set of indicators. This paper first offers a theoretical framework for the selection of suitable indicators for land use impact assessment, based on ecosystem thermodynamics. According to recent theories on the thermodynamics of open systems, a goal function of ecosystems is to maximize the dissipation of exogenic exergy fluxes by maximizing the internal exergy storage under form of biomass, biodiversity and complex trophical networks. Human impact may decrease this ecosystem exergy level by simplification, i.e. decreasing biomass and destroying internal complexity. Within this theoretical framework, we then studied possibilities for assessing the land use impact in a more direct way by measuring the ecosystems' capacity to dissipate solar exergy. Measuring ecosystem thermal characteristics by using remote sensing techniques was considered a promising tool. Once operational, it could offer a quick and cheap alternative to quantify land use impacts in any terrestrial ecosystem of any size. Recommendations are given for further exploration of this method and for its integration into an ISO compatible LCA framework

In situ radiation test of silicon and diamond detectors operating in superfluid helium and developed for beam loss monitoring

Energy Technology Data Exchange (ETDEWEB)

Kurfürst, C.; Dehning, B.; Sapinski, M.; Bartosik, M.R.; Eisel, T.; Fabjan, C.; Rementeria, C.A. [CERN, Geneva (Switzerland); Griesmayer, E. [CIVIDEC Instrumentation, GmbH, Vienna (Austria); Eremin, V. [Ioffe Institute, St. Petersburg (Russian Federation); Verbitskaya, E., E-mail: elena.verbitskaya@cern.ch [Ioffe Institute, St. Petersburg (Russian Federation); Zabrodskii, A.; Fadeeva, N.; Tuboltsev, Y.; Eremin, I. [Ioffe Institute, St. Petersburg (Russian Federation); Egorov, N. [Research Institute of Material Science and Technology, Zelenograd, Moscow (Russian Federation); Härkönen, J.; Luukka, P.; Tuominen, E. [Helsinki Institute of Physics, Helsinki (Finland)

2015-05-11

As a result of the foreseen increase in the luminosity of the Large Hadron Collider, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the results of ongoing research efforts targeting the upgrading of the monitoring system by exploiting Beam Loss Monitor detectors based on semiconductors located as close as possible to the superconducting coils of the triplet magnets. In practice, this means that the detectors will have to be immersed in superfluid helium inside the cold mass and operate at 1.9 K. Additionally, the monitoring system is expected to survive 20 years of LHC operation, resulting in an estimated radiation fluence of 1×10{sup 16} proton/cm{sup 2}, which corresponds to a dose of about 2 MGy. In this study, we monitored the signal degradation during the in situ irradiation when silicon and single-crystal diamond detectors were situated in the liquid/superfluid helium and the dependences of the collected charge on fluence and bias voltage were obtained. It is shown that diamond and silicon detectors can operate at 1.9 K after 1×10{sup 16} p/cm{sup 2} irradiation required for application as BLMs, while the rate of the signal degradation was larger in silicon detectors than in the diamond ones. For Si detectors this rate was controlled mainly by the operational mode, being larger at forward bias voltage. - Highlights: • Silicon and diamond detectors are proposed for beam loss monitoring at LHC. • The first in situ radiation test of Si and diamond detectors at 1.9 K is described. • Both diamond and silicon detectors survived after 1×10{sup 16} p/cm{sup 2} irradiation at 1.9 K. • The rate of Si detectors degradation depends on bias polarity and is larger at V{sub forw}. • Sensitivity of Si detectors irradiated to 1×10{sup 16} p/cm{sup 2} is independent on resistivity.

Assessing ecosystem effects of reservoir operations using food web-energy transfer and water quality models

Science.gov (United States)

Saito, L.; Johnson, B.M.; Bartholow, J.; Hanna, R.B.

2001-01-01

We investigated the effects on the reservoir food web of a new temperature control device (TCD) on the dam at Shasta Lake, California. We followed a linked modeling approach that used a specialized reservoir water quality model to forecast operation-induced changes in phytoplankton production. A food web–energy transfer model was also applied to propagate predicted changes in phytoplankton up through the food web to the predators and sport fishes of interest. The food web–energy transfer model employed a 10% trophic transfer efficiency through a food web that was mapped using carbon and nitrogen stable isotope analysis. Stable isotope analysis provided an efficient and comprehensive means of estimating the structure of the reservoir's food web with minimal sampling and background data. We used an optimization procedure to estimate the diet proportions of all food web components simultaneously from their isotopic signatures. Some consumers were estimated to be much more sensitive than others to perturbations to phytoplankton supply. The linked modeling approach demonstrated that interdisciplinary efforts enhance the value of information obtained from studies of managed ecosystems. The approach exploited the strengths of engineering and ecological modeling methods to address concerns that neither of the models could have addressed alone: (a) the water quality model could not have addressed quantitatively the possible impacts to fish, and (b) the food web model could not have examined how phytoplankton availability might change due to reservoir operations.

Ecosystem services as a common language for coastal ecosystem-based management.

Science.gov (United States)

Granek, Elise F; Polasky, Stephen; Kappel, Carrie V; Reed, Denise J; Stoms, David M; Koch, Evamaria W; Kennedy, Chris J; Cramer, Lori A; Hacker, Sally D; Barbier, Edward B; Aswani, Shankar; Ruckelshaus, Mary; Perillo, Gerardo M E; Silliman, Brian R; Muthiga, Nyawira; Bael, David; Wolanski, Eric

2010-02-01

Ecosystem-based management is logistically and politically challenging because ecosystems are inherently complex and management decisions affect a multitude of groups. Coastal ecosystems, which lie at the interface between marine and terrestrial ecosystems and provide an array of ecosystem services to different groups, aptly illustrate these challenges. Successful ecosystem-based management of coastal ecosystems requires incorporating scientific information and the knowledge and views of interested parties into the decision-making process. Estimating the provision of ecosystem services under alternative management schemes offers a systematic way to incorporate biogeophysical and socioeconomic information and the views of individuals and groups in the policy and management process. Employing ecosystem services as a common language to improve the process of ecosystem-based management presents both benefits and difficulties. Benefits include a transparent method for assessing trade-offs associated with management alternatives, a common set of facts and common currency on which to base negotiations, and improved communication among groups with competing interests or differing worldviews. Yet challenges to this approach remain, including predicting how human interventions will affect ecosystems, how such changes will affect the provision of ecosystem services, and how changes in service provision will affect the welfare of different groups in society. In a case study from Puget Sound, Washington, we illustrate the potential of applying ecosystem services as a common language for ecosystem-based management.

In situ radiation test of silicon and diamond detectors operating in superfluid helium and developed for beam loss monitoring

Science.gov (United States)

Kurfürst, C.; Dehning, B.; Sapinski, M.; Bartosik, M. R.; Eisel, T.; Fabjan, C.; Rementeria, C. A.; Griesmayer, E.; Eremin, V.; Verbitskaya, E.; Zabrodskii, A.; Fadeeva, N.; Tuboltsev, Y.; Eremin, I.; Egorov, N.; Härkönen, J.; Luukka, P.; Tuominen, E.

2015-05-01

As a result of the foreseen increase in the luminosity of the Large Hadron Collider, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the results of ongoing research efforts targeting the upgrading of the monitoring system by exploiting Beam Loss Monitor detectors based on semiconductors located as close as possible to the superconducting coils of the triplet magnets. In practice, this means that the detectors will have to be immersed in superfluid helium inside the cold mass and operate at 1.9 K. Additionally, the monitoring system is expected to survive 20 years of LHC operation, resulting in an estimated radiation fluence of 1×1016 proton/cm2, which corresponds to a dose of about 2 MGy. In this study, we monitored the signal degradation during the in situ irradiation when silicon and single-crystal diamond detectors were situated in the liquid/superfluid helium and the dependences of the collected charge on fluence and bias voltage were obtained. It is shown that diamond and silicon detectors can operate at 1.9 K after 1×1016 p/cm2 irradiation required for application as BLMs, while the rate of the signal degradation was larger in silicon detectors than in the diamond ones. For Si detectors this rate was controlled mainly by the operational mode, being larger at forward bias voltage.

Ecosystem Services

Science.gov (United States)

Ecosystem goods and services are the many life-sustaining benefits we receive from nature and contribute to environmental and human health and well-being. Ecosystem-focused research will develop methods to measure ecosystem goods and services.

Biodiversity and Ecosystem Functioning: Exploring Principles of Ecology with Agricultural Plants

Science.gov (United States)

Ruesink, Jennifer; O'Connor, Eileen; Sparks, Grace

2006-01-01

To date, little of the ecological research on biological diversity and ecosystem functioning has been carried out in agricultural systems, despite the fact that agriculture is a major contributor to loss of native habitats and species. However, agricultural research has demonstrated that polycultures of multiple crop species can have higher total…

Wind Erosion Caused by Land Use Changes Significantly Reduces Ecosystem Carbon Storage and Carbon Sequestration Potentials in Grassland

Science.gov (United States)

Li, P.; Chi, Y. G.; Wang, J.; Liu, L.

2017-12-01

Wind erosion exerts a fundamental influence on the biotic and abiotic processes associated with ecosystem carbon (C) cycle. However, how wind erosion under different land use scenarios will affect ecosystem C balance and its capacity for future C sequestration are poorly quantified. Here, we established an experiment in a temperate steppe in Inner Mongolia, and simulated different intensity of land uses: control, 50% of aboveground vegetation removal (50R), 100% vegetation removal (100R) and tillage (TI). We monitored lateral and vertical carbon flux components and soil characteristics from 2013 to 2016. Our study reveals three key findings relating to the driving factors, the magnitude and consequence of wind erosion on ecosystem C balance: (1) Frequency of heavy wind exerts a fundamental control over the severity of soil erosion, and its interaction with precipitation and vegetation characteristics explained 69% variation in erosion intensity. (2) With increases in land use intensity, the lateral C flux induced by wind erosion increased rapidly, equivalent to 33%, 86%, 111% and 183% of the net ecosystem exchange of the control site under control, 50R, 100R and TI sites, respectively. (3) After three years' treatment, erosion induced decrease in fine fractions led to 31%, 43%, 85% of permanent loss of C sequestration potential in the surface 5cm soil for 50R, 100R and TI sites. Overall, our study demonstrates that lateral C flux associated with wind erosion is too large to be ignored. The loss of C-enriched fine particles not only reduces current ecosystem C content, but also results in irreversible loss of future soil C sequestration potential. The dynamic soil characteristics need be considered when projecting future ecosystem C balance in aeolian landscape. We also propose that to maintain the sustainability of grassland ecosystems, land managers should focus on implementing appropriate land use rather than rely on subsequent managements on degraded soils.

Losses of ecosystem service values in the Taihu Lake Basin from 1979 to 2010

Science.gov (United States)

Zhang, Hui; Wang, Qiao; Li, Guangyu; Zhang, Hanpei; Zhang, Jue

2017-06-01

The Taihu Lake Basin, an east-coastal developed area, is one of the fastest-growing metropolitan areas in China. Ecosystem services in the Taihu Lake Basin have been overexploited and jeopardized. Based on land-use and land-cover change (LUCC) data from 1979, 1984, 2000, and 2010, in conjunction with the adjusted ecosystem service values (ESV), changes in ESV were analyzed in detail. Results revealed that LUCC resulted in a substantial decrease in total ESV from 3.92 billion in 1979 to 2.98 billion in 2010. The ESV of cropland decreased from 1.64 billion in 1979 to 1.34 billion in 2010, which represented a 20.28% reduction. The ESV of water areas decreased from 1.08 billion in 1979 to 0.36 billion in 2010, which represented a 65.62% reduction mainly because of a decline in water quality. In terms of annual change rate, cropland and water areas showed a sustained downward trend. Spatially, ESV declines were mainly observed in Suzhou, Wuxi, Changzhou, and Shanghai, probably due to a combination of economic progress, population growth, and rapid urbanization. The research results can be a useful reference for policymakers in mitigating ESV decline.

Riverine ecosystem services and the thermoelectric sector: strategic issues facing the Northeastern United States

Science.gov (United States)

Miara, A.; Vorosmarty, C. J.; Stewart, R.; Wollheim, W. M.; Rosenzweig, B.

2013-12-01

Major strategic issues facing the global thermoelectric sector include environmental regulation, climate change and increasing electricity demand. We have addressed such issues by modeling thermoelectric generation in the Northeastern United States that is reliant on cooling under five sensitivity tests to evaluate losses/gains in power production, thermal pollution and suitable aquatic habitat, comparing the contemporary baseline (2000-2010) with potential future states. Integral to the analysis, we developed a methodology to quantify river water availability for cooling, which we define as an ecosystem service. Projected climate conditions reduce river water available for efficient power plant operations and the river's capacity to absorb waste heat, causing a loss of regional thermoelectric generation (RTG) (2.5%) in some summers that, compared to the contemporary baseline, is equal to the summertime electricity consumption of 1.3 million Northeastern US homes. Vulnerabilities to warm temperatures and thermal pollution can be alleviated through the use of more efficient natural gas (NG) power plants that have a reduced reliance on cooling water. Conversion of once-through (OT) to cooling tower (CT) systems and the Clean Water Act (CWA) temperature limit regulation, both of which reduce efficiencies at the single plant level, show potential to yield beneficial increases in RTG. This is achieved by obviating the need for large volumes of river water, thereby reducing plant-to-plant interferences through lowering the impact of upstream thermal pollution and preserving a minimum standard of cooling water. The results and methodology framework presented here, which can be extrapolated to other regional assessments with contrasting climates and thermoelectric profiles, can identify opportunities and support decision-making to achieve more efficient energy systems and riverine ecosystem protection.

Review of ecosystem level impacts of emerald ash borer on black ash wetlands: What does the future hold?

Science.gov (United States)

Randall K. Kolka; Anthony W. D' Amato; Joseph W. Wagenbrenner; Robert A. Slesak; Thomas G. Pypker; Melissa B. Youngquist; Alexis R. Grinde; Brian J. Palik

2018-01-01

The emerald ash borer (EAB) is rapidly spreading throughout eastern North America and devastating ecosystems where ash is a component tree. This rapid and sustained loss of ash trees has already resulted in ecological impacts on both terrestrial and aquatic ecosystems and is projected to be even more severe as EAB invades black ash-dominated wetlands of the western...

Ecosystem Model Skill Assessment. Yes We Can!

Science.gov (United States)

Olsen, Erik; Fay, Gavin; Gaichas, Sarah; Gamble, Robert; Lucey, Sean; Link, Jason S

2016-01-01

Accelerated changes to global ecosystems call for holistic and integrated analyses of past, present and future states under various pressures to adequately understand current and projected future system states. Ecosystem models can inform management of human activities in a complex and changing environment, but are these models reliable? Ensuring that models are reliable for addressing management questions requires evaluating their skill in representing real-world processes and dynamics. Skill has been evaluated for just a limited set of some biophysical models. A range of skill assessment methods have been reviewed but skill assessment of full marine ecosystem models has not yet been attempted. We assessed the skill of the Northeast U.S. (NEUS) Atlantis marine ecosystem model by comparing 10-year model forecasts with observed data. Model forecast performance was compared to that obtained from a 40-year hindcast. Multiple metrics (average absolute error, root mean squared error, modeling efficiency, and Spearman rank correlation), and a suite of time-series (species biomass, fisheries landings, and ecosystem indicators) were used to adequately measure model skill. Overall, the NEUS model performed above average and thus better than expected for the key species that had been the focus of the model tuning. Model forecast skill was comparable to the hindcast skill, showing that model performance does not degenerate in a 10-year forecast mode, an important characteristic for an end-to-end ecosystem model to be useful for strategic management purposes. We identify best-practice approaches for end-to-end ecosystem model skill assessment that would improve both operational use of other ecosystem models and future model development. We show that it is possible to not only assess the skill of a complicated marine ecosystem model, but that it is necessary do so to instill confidence in model results and encourage their use for strategic management. Our methods are applicable

Biodiversity as a solution to mitigate climate change impacts on the functioning of forest ecosystems.

Science.gov (United States)

Hisano, Masumi; Searle, Eric B; Chen, Han Y H

2018-02-01

Forest ecosystems are critical to mitigating greenhouse gas emissions through carbon sequestration. However, climate change has affected forest ecosystem functioning in both negative and positive ways, and has led to shifts in species/functional diversity and losses in plant species diversity which may impair the positive effects of diversity on ecosystem functioning. Biodiversity may mitigate climate change impacts on (I) biodiversity itself, as more-diverse systems could be more resilient to climate change impacts, and (II) ecosystem functioning through the positive relationship between diversity and ecosystem functioning. By surveying the literature, we examined how climate change has affected forest ecosystem functioning and plant diversity. Based on the biodiversity effects on ecosystem functioning (B→EF), we specifically address the potential for biodiversity to mitigate climate change impacts on forest ecosystem functioning. For this purpose, we formulate a concept whereby biodiversity may reduce the negative impacts or enhance the positive impacts of climate change on ecosystem functioning. Further B→EF studies on climate change in natural forests are encouraged to elucidate how biodiversity might influence ecosystem functioning. This may be achieved through the detailed scrutiny of large spatial/long temporal scale data sets, such as long-term forest inventories. Forest management strategies based on B→EF have strong potential for augmenting the effectiveness of the roles of forests in the mitigation of climate change impacts on ecosystem functioning. © 2017 Cambridge Philosophical Society.

Pollination ecosystem services in South African agricultural systems

OpenAIRE

Annalie Melin; Mathieu Rouget; Jeremy J. Midgley; John S. Donaldson

2014-01-01

Insect pollinators, both managed and wild, have become a focus of global scientific, political and media attention because of their apparent decline and the perceived impact of this decline on crop production. Crop pollination by insects is an essential ecosystem service that increases the yield and quality of approximately 35% of crops worldwide. Pollinator declines are a consequence of multiple environmental pressures, e.g. habitat transformation and fragmentation, loss of floral resources,...

Balanced Harvest in the Real World. Scientific, Policy and Operational Issues in an Ecosystem Approach to Fisheries

NARCIS (Netherlands)

Garcia, S.M.; Bianchi, G.; Charles, A.; Kolding, J.; Rice, J.; Rochet, M.J.; Zhou, S.; Delius, G.; Reid, D.; Zwieten, van P.A.M.; Atcheson, M.; Bartley, D.; Borges, L.; Bundy, A.; Dagorn, L.; Dunn, D.; Hall, M.; Heino, M.; Jacobsen, B.; Jacobsen, N.S.; Law, R.; Makino, M.; Martin, F.; Skern-Mauritzen, M.; Suuronen, P.; Symons, D.

2015-01-01

The concept of the Ecosystem Approach has entered the fishery harvesting discussions both from fishery perspectives (Reykjavik Declaration; FAO 2003 Annex to the Code of Conduct and from the principles of the Ecosystem Approach adopted by the CBD in 1995. Both perspectives establish the need to

Solar radiation uncorks the lignin bottleneck on plant litter decomposition in terrestrial ecosystems

Science.gov (United States)

Austin, A.; Ballare, C. L.; Méndez, M. S.

2015-12-01

Plant litter decomposition is an essential process in the first stages of carbon and nutrient turnover in terrestrial ecosystems, and together with soil microbial biomass, provide the principal inputs of carbon for the formation of soil organic matter. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in low rainfall ecosystems; however, the generality of this process as a control on carbon cycling in terrestrial ecosystems is not known, and the indirect effects of photodegradation on biotic stimulation of carbon turnover have been debated in recent studies. We demonstrate that in a wide range of plant species, previous exposure to solar radiation, and visible light in particular, enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility for microbial enzymes to plant litter carbohydrates due to a reduction in lignin content. Photodegradation of plant litter reduces the structural and chemical bottleneck imposed by lignin in secondary cell walls. In litter from woody plant species, specific interactions with ultraviolet radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized positive effect of solar radiation exposure on subsequent microbial activity is mediated by increased accessibility to cell wall polysaccharides, which suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release and the carbon balance in a broad range of terrestrial ecosystems.

The roles of dimensionality, canopies and complexity in ecosystem monitoring.

Directory of Open Access Journals (Sweden)

Christopher H R Goatley

Full Text Available Canopies are common among autotrophs, increasing their access to light and thereby increasing competitive abilities. If viewed from above canopies may conceal objects beneath them creating a 'canopy effect'. Due to complexities in collecting 3-dimensional data, most ecosystem monitoring programmes reduce dimensionality when sampling, resorting to planar views. The resultant 'canopy effects' may bias data interpretation, particularly following disturbances. Canopy effects are especially relevant on coral reefs where coral cover is often used to evaluate and communicate ecosystem health. We show that canopies hide benthic components including massive corals and algal turfs, and as planar views are almost ubiquitously used to monitor disturbances, the loss of vulnerable canopy-forming corals may bias findings by presenting pre-existing benthic components as an altered system. Our reliance on planar views in monitoring ecosystems, especially coral cover on reefs, needs to be reassessed if we are to better understand the ecological consequences of ever more frequent disturbances.

Consequences of biodiversity loss diverge from expectation due to post-extinction compensatory responses

Science.gov (United States)

Thomsen, Matthias S.; Garcia, Clement; Bolam, Stefan G.; Parker, Ruth; Godbold, Jasmin A.; Solan, Martin

2017-03-01

Consensus has been reached that global biodiversity loss impairs ecosystem functioning and the sustainability of services beneficial to humanity. However, the ecosystem consequences of extinction in natural communities are moderated by compensatory species dynamics, yet these processes are rarely accounted for in impact assessments and seldom considered in conservation programmes. Here, we use marine invertebrate communities to parameterise numerical models of sediment bioturbation - a key mediator of biogeochemical cycling - to determine whether post-extinction compensatory mechanisms alter biodiversity-ecosystem function relations following non-random extinctions. We find that compensatory dynamics lead to trajectories of sediment mixing that diverge from those without compensation, and that the form, magnitude and variance of each probabilistic distribution is highly influenced by the type of compensation and the functional composition of surviving species. Our findings indicate that the generalized biodiversity-function relation curve, as derived from multiple empirical investigations of random species loss, is unlikely to yield representative predictions for ecosystem properties in natural systems because the influence of post-extinction community dynamics are under-represented. Recognition of this problem is fundamental to management and conservation efforts, and will be necessary to ensure future plans and adaptation strategies minimize the adverse impacts of the biodiversity crisis.

Effects on the function of Arctic ecosystems in the short- and long-term perspectives.

Science.gov (United States)

Callaghan, Terry V; Björn, Lars Olof; Chernov, Yuri; Chapin, Terry; Christensen, Torben R; Huntley, Brian; Ims, Rolf A; Johansson, Margareta; Jolly, Dyanna; Jonasson, Sven; Matveyeva, Nadya; Panikov, Nicolai; Oechel, Walter; Shaver, Gus

2004-11-01

Historically, the function of Arctic ecosystems in terms of cycles of nutrients and carbon has led to low levels of primary production and exchanges of energy, water and greenhouse gases have led to low local and regional cooling. Sequestration of carbon from atmospheric CO2, in extensive, cold organic soils and the high albedo from low, snow-covered vegetation have had impacts on regional climate. However, many aspects of the functioning of Arctic ecosystems are sensitive to changes in climate and its impacts on biodiversity. The current Arctic climate results in slow rates of organic matter decomposition. Arctic ecosystems therefore tend to accumulate organic matter and elements despite low inputs. As a result, soil-available elements like nitrogen and phosphorus are key limitations to increases in carbon fixation and further biomass and organic matter accumulation. Climate warming is expected to increase carbon and element turnover, particularly in soils, which may lead to initial losses of elements but eventual, slow recovery. Individual species and species diversity have clear impacts on element inputs and retention in Arctic ecosystems. Effects of increased CO2 and UV-B on whole ecosystems, on the other hand, are likely to be small although effects on plant tissue chemisty, decomposition and nitrogen fixation may become important in the long-term. Cycling of carbon in trace gas form is mainly as CO2 and CH4. Most carbon loss is in the form of CO2, produced by both plants and soil biota. Carbon emissions as methane from wet and moist tundra ecosystems are about 5% of emissions as CO2 and are responsive to warming in the absence of any other changes. Winter processes and vegetation type also affect CH4 emissions as well as exchanges of energy between biosphere and atmosphere. Arctic ecosystems exhibit the largest seasonal changes in energy exchange of any terrestrial ecosystem because of the large changes in albedo from late winter, when snow reflects most

Elevated moisture stimulates carbon loss from mineral soils by releasing protected organic matter.

Science.gov (United States)

Huang, Wenjuan; Hall, Steven J

2017-11-24

Moisture response functions for soil microbial carbon (C) mineralization remain a critical uncertainty for predicting ecosystem-climate feedbacks. Theory and models posit that C mineralization declines under elevated moisture and associated anaerobic conditions, leading to soil C accumulation. Yet, iron (Fe) reduction potentially releases protected C, providing an under-appreciated mechanism for C destabilization under elevated moisture. Here we incubate Mollisols from ecosystems under C 3 /C 4 plant rotations at moisture levels at and above field capacity over 5 months. Increased moisture and anaerobiosis initially suppress soil C mineralization, consistent with theory. However, after 25 days, elevated moisture stimulates cumulative gaseous C-loss as CO 2 and CH 4 to >150% of the control. Stable C isotopes show that mineralization of older C 3 -derived C released following Fe reduction dominates C losses. Counter to theory, elevated moisture may significantly accelerate C losses from mineral soils over weeks to months-a critical mechanistic deficiency of current Earth system models.

Plant hydraulic diversity buffers forest ecosystem responses to drought

Science.gov (United States)

Anderegg, W.; Konings, A. G.; Trugman, A. T.; Pacala, S. W.; Yu, K.; Sulman, B. N.; Sperry, J.; Bowling, D. R.

2017-12-01

Drought impacts carbon, water, and energy cycles in forests and may pose a fundamental threat to forests in future climates. Plant hydraulic transport of water is central to tree drought responses, including curtailing of water loss and the risk of mortality during drought. The effect of biodiversity on ecosystem function has typically been examined in grasslands, yet the diversity of plant hydraulic strategies may influence forests' response to drought. In a combined analysis of eddy covariance measurements, remote-sensing data of plant water content variation, model simulations, and plant hydraulic trait data, we test the degree to which plant water stress schemes influence the carbon cycle and how hydraulic diversity within and across ecosystems affects large-scale drought responses. We find that current plant functional types are not well-suited to capture hydraulic variation and that higher hydraulic diversity buffers ecosystem variation during drought. Our results demonstrate that tree functional diversity, particularly hydraulic diversity, may be critical to simulate in plant functional types in current land surface model projections of future vegetation's response to climate extremes.

Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO₂ exposure in a subtropical oak woodland.

Science.gov (United States)

Hungate, Bruce A; Dijkstra, Paul; Wu, Zhuoting; Duval, Benjamin D; Day, Frank P; Johnson, Dale W; Megonigal, J Patrick; Brown, Alisha L P; Garland, Jay L

2013-11-01

Rising atmospheric carbon dioxide (CO₂) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO₂. We used open-top chambers to manipulate CO₂ during regrowth after fire, and measured C, N and tracer (15) N in ecosystem components throughout the experiment. Elevated CO₂ increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO₂ increased soil microbial activity and labile soil C, but more slowly cycling soil C pools tended to decline. Recovery of a long-term (15) N tracer indicated that CO₂ exposure increased N losses and altered N distribution, with no effect on N inputs. Increased plant C accrual was accompanied by higher soil microbial activity and increased C losses from soil, yielding no statistically detectable effect of elevated CO₂ on net ecosystem C uptake. These findings challenge the treatment of terrestrial ecosystems responses to elevated CO₂ in current biogeochemical models, where the effect of elevated CO₂ on ecosystem C balance is described as enhanced photosynthesis and plant growth with decomposition as a first-order response. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Ecosystem Development after Mangrove Wetland Creation: Plant-Soil Change across a 20-year Chronosequence

Science.gov (United States)

Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland loss. However, ecosystem development and functional equivalence in restored and created mangrove wetlands is poorly understood. We compared a 20-yr chrono...

Current status of low power/shutdown PSA and accident sequence analysis for loss of RHR during mid-loop operation

International Nuclear Information System (INIS)

Park, Chang Kyu; Choi, Young; Kim, Tae Woon; Jin, Young Ho

1994-07-01

Probabilistic safety assessment (PSA) has been applied to only full-power operation of nuclear power plant (NPP), but some events which were recently occurred could reach severe plant damage state. Thus, various countries around the world have focused their interests on the evaluation for low power/shutdown (LP/S) operation. This report covers the main stream of LP/S PSA methodology, current status of LP/S PSA practices and results, and accident sequence analysis for loss of RHR during mid-loop operation. Therefore this report would be helpful for us to practice LP/S PSA for YGN 5,6 NPP which will be built in the near future. Also the results of accident sequence analysis show that operator's mis-diagnosis and failure of recovery action would initiate core damage during LP/S operation. In summary, overall environmental improvements (equipments, procedures, Tech Spec, etc, ...) and operating support system will be very useful to reduce risk during LP/S operation. (Author) 5 figs., 9 tabs

Non-random species loss in bacterial communities reduces antifungal volatile production

NARCIS (Netherlands)

Hol, G.; Garbeva, P.; Hordijk, C.; Hundscheid, M.P.J.; Klein Gunnewiek, P.J.A.; Agtmaal, van M.; Boer, de W.

2015-01-01

The contribution of low-abundance microbial species to soil ecosystems is easily overlooked because there is considerable overlap between metabolic abilities (functional redundancy) of dominant and subordinate microbial species. Here we studied how loss of less abundant soil bacteria affected the

7 CFR 1430.306 - Determination of losses incurred.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Determination of losses incurred. 1430.306 Section... Disaster Assistance Payment Program § 1430.306 Determination of losses incurred. (a) Eligible payable losses are calculated on a dairy operation by dairy operation basis and are limited to those occurring in...

Measuring Entrepreneurial Ecosystems

OpenAIRE

Stam, F.C.

2017-01-01

How can entrepreneurial ecosystems and productive entrepreneurship can be traced empirically and how is entrepreneurship related to entrepreneurial ecosystems. The analyses in this chapter show the value of taking a systems view on the context of entrepreneurship. We measure entrepreneurial ecosystem elements and use these to compose an entrepreneurial ecosystem index. Next, we measure the output of entrepreneurial ecosystems with different indicators of high-growth firms. We use the 12 provi...

The marine ecosystem services approach in a fisheries management perspective

OpenAIRE

Søren Anker Pedersen; Hans Lassen; Hans Frost

2015-01-01

This paper reviews the concepts of marine ecosystem services and their economic valuation in a European fisheries management perspective. We find that the concept is at best cumbersome for advising on how best to regulate fisheries even in an ecosystem context.We propose that operational fisheries management must consider three different types of analysis, the yield of and the effect of fishing on the commercial species, the effects of fishing on habitats and non-commercial species and finall...

First Lagrangian ROMS–IBM simulations indicate large losses of ...

African Journals Online (AJOL)

... and models suggests that passive biological material such as eggs and larvae can be advected offshore away from the Agulhas Bank, South Africa, and hence removed from the ecosystem on which their survival and recruitment depends. Such losses have been cited as the root cause of the sudden drop in annual squid ...

Detection of Equipment Faults Before Beam Loss

CERN Document Server

Galambos, J.

2016-01-01

High-power hadron accelerators have strict limits on fractional beam loss. In principle, once a high-quality beam is set up in an acceptable state, beam loss should remain steady. However, in practice, there are many trips in operational machines, owing to excessive beam loss. This paper deals with monitoring equipment health to identify precursor signals that indicate an issue with equipment that will lead to unacceptable beam loss. To this end, a variety of equipment and beam signal measurements are described. In particular, several operational examples from the Spallation Neutron Source (SNS) of deteriorating equipment functionality leading to beam loss are reported.

Soil ecology and ecosystem services of dairy and semi-natural grasslands on peat

NARCIS (Netherlands)

Deru, Joachim G.C.; Bloem, Jaap; Goede, de Ron; Keidel, Harm; Kloen, Henk; Rutgers, Michiel; Akker, van den Jan; Brussaard, Lijbert; Eekeren, van Nick

2018-01-01

Peat wetlands are of major importance for ecosystem services such as carbon storage, water regulation and maintenance of biodiversity. However, peat drainage for farming leads to CO2 emission, soil subsidence and biodiversity losses. In the peat areas in the Netherlands, solutions are sought in

Preservation of beam loss induced quenches, beam lifetime and beam loss measurements with the HERA-p beam-loss-monitor system

International Nuclear Information System (INIS)

Wittenburg, K.

1994-01-01

The beam-loss-monitors (BLMs) in the HERA-Proton-ring (HERAp) must fulfil the following requirements: They have to measure losses sensitive and fast enough to prevent the superconducting magnets from beam loss induced quenching; the dynamic range of the monitors must exceed several decades in order to measure losses during beam lifetimes of hundreds of hours as well as the much stronger losses that may quench superconducting magnets; they have to be insensitive to the synchrotron radiation of the adjacent electron-ring (HERAe); and their radiation hardness must allow a monitor-lifetime of a few years of HERA operation. These requirements are well satisfied by the HERAp-BLM-System. (orig.)

Nitrogen Dynamics in European Forest Ecosystems: Considerations regarding Anthropogenic Nitrogen Depositions

OpenAIRE

Agren, G.I.; Kauppi, P.

1983-01-01

This study deals with the nutrient cycle of forest ecosystems over large geographic regions in Europe as affected by nitrogen deposition. The view is taken that the nitrogen cycle of a forest ecosystem has a maximum capacity for circulating nitrogen. Two different cases are defined: case (1) in which the nutrient cycle functions below its maximum capacity, and case (2) in which the circulation operates at the maximum level.

Mapping Ecosystem Services

OpenAIRE

Georgiev,Teodor; Burkhard,Benjamin; Maes,Joachim

2017-01-01

Ecosystem services are the contributions of ecosystem structure and function (in combination with other inputs) to human well-being. That means, humankind is strongly dependent on well-functioning ecosystems and natural capital that are the base for a constant flow of ecosystem services from nature to society. Therefore ecosystem services have the potential to become a major tool for policy and decision making on global, national, regional and local scales. Possible applications are manifold:...

7 CFR 1430.606 - Determination of losses incurred.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Determination of losses incurred. 1430.606 Section... Disaster Assistance Payment Program II (DDAP-II) § 1430.606 Determination of losses incurred. (a) Eligible payable losses are calculated on a dairy operation by dairy operation basis and are limited to those...

Australia's TERN: Building, Sustaining and Advancing Collaborative Long Term Ecosystem Research Networks

Science.gov (United States)

HEld, A. A.; Phinn, S. R.

2012-12-01

TERN is Australia's Terrestrial Ecosystem Research Network (www.tern.org.au) is one of several environmental data collection, storage and sharing projects developed through the government's research infrastructure programs 2008-2014. This includes terrestrial and coastal ecosystem data collection infrastructure across multiple disciplines, hardware, software and processes used to store, analyse and integrate data sets. TERN's overall objective is to build the collaborations, infrastructure and programs to meet the needs of ecosystem science communities in Australia in the long term, through institutional frameworks necessary to establish a national terrestrial ecosystem site and observational network, coordinated networks enabling cooperation and operational experience; public access to quality assured and appropriately licensed data; and allowing the terrestrial ecosystem research community to define and sustain the terrestrial observing paradigm into the longer term. This paper explains how TERN was originally established, and now operates, along with plans to sustain itself in the future. TERN is implemented through discipline/technical groups referred to as "TERN Facilities". Combined, the facilities provide observations of surface mass and energy fluxes over key ecosystems, biophysical remote sensing data, ecological survey plots, soils information, and coastal ecosystems and associated water quality variables across Australia. Additional integrative facilities cover elements of ecoinformatics, data-scaling and modelling, and linking science to management. A central coordination and portal facility provides meta-data storage, data identification, legal and licensing support. Data access, uploading, meta-data generation, DOI attachment and licensing is completed at each facility's own portal level. TERN also acts as the open-data repository of choice for Australian scientists required to publish their data. Several key lessons we have learnt, will be presented

Blacklist Ecosystem Analysis Update: 2014

Science.gov (United States)

2014-12-01

example, we checked to see if any of the blacklisted IP addresses were known sinkhole IP addresses. This information would essentially invalidate the...indicator as an indicator of malicious activity, since sinkholes are operated by CERTCC-2014-82 4 Blacklist Ecosystem Analysis CERT/CC network defenders who...clean up and collect intelligence on threats. Only one list out of 67, LI_3, contained any sinkhole IP addresses and that list contained only 10. All

The importance of rapid, disturbance-induced losses in carbon management and sequestration

Science.gov (United States)

Breshears, D.D.; Allen, Craig D.

2002-01-01

Management of terrestrial carbon fluxes is being proposed as a means of increasing the amount of carbon sequestered in the terrestrial biosphere. This approach is generally viewed only as an interim strategy for the coming decades while other longer-term strategies are developed and implemented — the most important being the direct reduction of carbon emissions. We are concerned that the potential for rapid, disturbance-induced losses may be much greater than is currently appreciated, especially by the decision-making community. Here we wish to: (1) highlight the complex and threshold-like nature of disturbances — such as fire and drought, as well as the erosion associated with each — that could lead to carbon losses; (2) note the global extent of ecosystems that are at risk of such disturbance-induced carbon losses; and (3) call for increased consideration of and research on the mechanisms by which large, rapid disturbance-induced losses of terrestrial carbon could occur. Our lack of ability as a scientific community to predict such ecosystem dynamics is precluding the effective consideration of these processes into strategies and policies related to carbon management and sequestration. Consequently, scientists need to do more to improve quantification of these potential losses and to integrate them into sound, sustainable policy options.

Mapping Ecosystem Services for Land Use Planning, the Case of Central Kalimantan

NARCIS (Netherlands)

Sumarga, E.; Hein, L.G.

2014-01-01

Indonesia is subject to rapid land use change. One of the main causes for the conversion of land is the rapid expansion of the oil palm sector. Land use change involves a progressive loss of forest cover, with major impacts on biodiversity and global CO2 emissions. Ecosystem services have been

Ecosystem Jenga!

Science.gov (United States)

Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.

2009-01-01

To give students a tangible model of an ecosystem and have them experience what could happen if a component of that ecosystem were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced ecosystem through a modification of the popular game Jenga. This activity can be…

Alpine ecosystems

Science.gov (United States)

P.W. Rundel; C.I. Millar

2016-01-01

Alpine ecosystems are typically defined as those areas occurring above treeline, while recognizing that alpine ecosystems at a local scale may be found below this boundary for reasons including geology, geomorphology, and microclimate. The lower limit of the alpine ecosystems, the climatic treeline, varies with latitude across California, ranging from about 3500 m in...

Solar energy development and aquatic ecosystems in the southwestern United States: potential impacts, mitigation, and research needs.

Science.gov (United States)

Grippo, Mark; Hayse, John W; O'Connor, Ben L

2015-01-01

The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.

Mapping environmental land use conflict potentials and ecosystem services in agricultural watersheds.

Science.gov (United States)

Kim, Ilkwon; Arnhold, Sebastian

2018-07-15

In mountainous watersheds, agricultural land use cause changes in ecosystem services, with trade-offs between crop production and erosion regulation. Management of these watersheds can generate environmental land use conflicts among regional stakeholders with different interests. Although several researches have made a start in mapping land use conflicts between human activities and conservation, spatial assessment of land use conflicts on environmental issues and ecosystem service trade-offs within agricultural areas has not been fully considered. In this study, we went further to map land use conflicts between agricultural preferences for crop production and environmental emphasis on erosion regulation. We applied an agricultural land suitability index, based on multi-criteria analysis, to estimate the spatial preference of agricultural activities, while applying the Revised Universal Soil Loss Equation (RUSLE) to reflect the environmental importance of soil erosion. Then, we classified the agricultural catchment into four levels of land use conflicts (lowest, low, high and highest) according to preference and importance of farmland areas, and we compared the classes by crop type. Soil loss in agricultural areas was estimated as 45.1thayr, and agricultural suitability as 0.873; this indicated that land use conflicts in the catchment could arise between severe soil erosion (environmental importance) and agricultural suitability (land preferences). Dry-field farms are mainly located in areas of low land use conflict level, where land preference outweighs environmental importance. When we applied farmland management scenarios with consideration of services, conversion to highest-conflict areas (Scenario 1) as 7.5% of the total area could reduce soil loss by 24.6%, while fallow land management (Scenario 2) could decrease soil loss 19.4% more than the current scenario (Business as usual). The result could maximize land management plans by extracting issues of spatial

Strategic ecosystems of Colombia

International Nuclear Information System (INIS)

Marquez Calle German

2002-01-01

The author relates the ecosystems in Colombia, he makes a relationship between ecosystems and population, utility of the ecosystems, transformation of the ecosystems and poverty and he shows a methodology of identification of strategic ecosystems

Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO2 exposure in a subtropical oak woodland

Science.gov (United States)

Hungate, Bruce A; Dijkstra, Paul; Wu, Zhuoting; Duval, Benjamin D; Day, Frank P; Johnson, Dale W; Megonigal, J Patrick; Brown, Alisha L P; Garland, Jay L

2013-01-01

Summary Rising atmospheric carbon dioxide (CO2) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO2. We used open-top chambers to manipulate CO2 during regrowth after fire, and measured C, N and tracer 15N in ecosystem components throughout the experiment. Elevated CO2 increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO2 increased soil microbial activity and labile soil C, but more slowly cycling soil C pools tended to decline. Recovery of a long-term 15N tracer indicated that CO2 exposure increased N losses and altered N distribution, with no effect on N inputs. Increased plant C accrual was accompanied by higher soil microbial activity and increased C losses from soil, yielding no statistically detectable effect of elevated CO2 on net ecosystem C uptake. These findings challenge the treatment of terrestrial ecosystems responses to elevated CO2 in current biogeochemical models, where the effect of elevated CO2 on ecosystem C balance is described as enhanced photosynthesis and plant growth with decomposition as a first-order response. PMID:23718224

Ecosystem regime shifts disrupt trophic structure.

Science.gov (United States)

Hempson, Tessa N; Graham, Nicholas A J; MacNeil, M Aaron; Hoey, Andrew S; Wilson, Shaun K

2018-01-01

Regime shifts between alternative stable ecosystem states are becoming commonplace due to the combined effects of local stressors and global climate change. Alternative states are characterized as substantially different in form and function from pre-disturbance states, disrupting the delivery of ecosystem services and functions. On coral reefs, regime shifts are typically characterized by a change in the benthic composition from coral to macroalgal dominance. Such fundamental shifts in the benthos are anticipated to impact associated fish communities that are reliant on the reef for food and shelter, yet there is limited understanding of how regime shifts propagate through the fish community over time, relative to initial or recovery conditions. This study addresses this knowledge gap using long-term data of coral reef regime shifts and recovery on Seychelles reefs following the 1998 mass bleaching event. It shows how trophic structure of the reef fish community becomes increasingly dissimilar between alternative reef ecosystem states (regime-shifted vs. recovering) with time since disturbance. Regime-shifted reefs developed a concave trophic structure, with increased biomass in base trophic levels as herbivorous species benefitted from increased algal resources. Mid trophic level species, including specialists such as corallivores, declined with loss of coral habitat, while biomass was retained in upper trophic levels by large-bodied, generalist invertivores. Recovering reefs also experienced an initial decline in mid trophic level biomass, but moved toward a bottom-heavy pyramid shape, with a wide range of feeding groups (e.g., planktivores, corallivores, omnivores) represented at mid trophic levels. Given the importance of coral reef fishes in maintaining the ecological function of coral reef ecosystems and their associated fisheries, understanding the effects of regime shifts on these communities is essential to inform decisions that enhance ecological

The importance of dissimilatory nitrate reduction to ammonium (DNRA) in the nitrogen cycle of coastal ecosystems

DEFF Research Database (Denmark)

Giblin, Anne E.; Tobias, Craig R.; Song, Bongkeun

2013-01-01

Until recently, it was believed that biological assimilation and gaseous nitrogen (N) loss through denitrification were the two major fates of nitrate entering or produced within most coastal ecosystems. Denitrification is often viewed as an important ecosystem service that removes reactive N from...... the ecosystem. However, there is a competing nitrate reduction process, dissimilatory nitrate reduction to ammonium (DNRA), that conserves N within the ecosystem. The recent application of nitrogen stable isotopes as tracers has generated growing evidence that DNRA is a major nitrogen pathway that cannot...... of denitrification and DNRA, and how the balance changes with increased nitrogen loading, is of critical importance for predicting eutrophication trajectories. Recent improvements in methods for assessing rates of DNRA have helped refine our understanding of the rates and controls of this process, but accurate...

Ecosystem impacts of hypoxia: thresholds of hypoxia and pathways to recovery

International Nuclear Information System (INIS)

Steckbauer, A; Duarte, C M; Vaquer-Sunyer, R; Carstensen, J; Conley, D J

2011-01-01

Coastal hypoxia is increasing in the global coastal zone, where it is recognized as a major threat to biota. Managerial efforts to prevent hypoxia and achieve recovery of ecosystems already affected by hypoxia are largely based on nutrient reduction plans. However, these managerial efforts need to be informed by predictions on the thresholds of hypoxia (i.e. the oxygen levels required to conserve biodiversity) as well as the timescales for the recovery of ecosystems already affected by hypoxia. The thresholds for hypoxia in coastal ecosystems are higher than previously thought and are not static, but regulated by local and global processes, being particularly sensitive to warming. The examination of recovery processes in a number of coastal areas managed for reducing nutrient inputs and, thus, hypoxia (Northern Adriatic; Black Sea; Baltic Sea; Delaware Bay; and Danish Coastal Areas) reveals that recovery timescales following the return to normal oxygen conditions are much longer than those of loss following the onset of hypoxia, and typically involve decadal timescales. The extended lag time for ecosystem recovery from hypoxia results in non-linear pathways of recovery due to hysteresis and the shift in baselines, affecting the oxygen thresholds for hypoxia through time.

Assessing antiquity and turnover of terrestrial ecosystems in eastern North America using fossil pollen data: A preliminary study

International Nuclear Information System (INIS)

Liu Yao; Jackson, Stephen T; Brewer, Simon; Williams, John W

2010-01-01

We explored formal approaches to identifying and interpreting the antiquity and turnover of terrestrial ecosystems in eastern North America using pollen records. Preliminary results of cluster analyses, receiver-operating characteristic (ROC) analyses, and likelihood estimation of ecosystem analog in a simple Bayesian model allow assessment of modern ecosystem antiquities and past ecosystem turnovers. Approaches discussed in this study thus provide a vehicle for further studies.

Context dependency and saturating effects of loss of rare soil microbes on plant productivity

Directory of Open Access Journals (Sweden)

Gera eHol

2015-06-01

Full Text Available Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing towards a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins.

Context dependency and saturating effects of loss of rare soil microbes on plant productivity.

Science.gov (United States)

Hol, W H Gera; de Boer, Wietse; de Hollander, Mattias; Kuramae, Eiko E; Meisner, Annelein; van der Putten, Wim H

2015-01-01

Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition, and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing toward a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins.

Aquatic ecosystems in the coal mining landscape of the upper Olifants River, and the way forward

CSIR Research Space (South Africa)

Oberholster, Paul J

2014-03-01

Full Text Available can provide guidance on managing water ecosystems in the future at various stages of mining operations, which include understanding the interface between water ecosystems and coal mining activities, assessing the likelihood of coal mining activities...

Environmental management of mangrove ecosystems. An approach for the Colombian case

International Nuclear Information System (INIS)

Uribe P, Johanna; Urrego G, Ligia E

2009-01-01

The aim of the present documental investigation is to analyze the published information on the current state of mangrove ecosystems and its management. A categorical system was established in order to facilitate the analysis of the compiled information. Firstly, the socioeconomic and biological importance of mangrove ecosystems is examined. The causes of environmental degradation of mangroves are analyzed. Four groups of causes were identified: global climate change, urban development, over exploitation of resources and land use changes. Likewise, the effects of the environmental degradation of the mangroves are classified into three groups: biological function deterioration, loss of consumable and not consumable goods and services. Additionally, the environmental management actions carried out in mangroves are analyzed, which implies, on one hand the normativity (both national and international) and on the other, the implemented management strategies. From the categorical analysis tendencies, gaps and ambiguities of the information compiled are identified. Finally, some useful conclusions and recommendations for future management of mangrove ecosystems are presented.

Consequences of tropical land use for multitrophic biodiversity and ecosystem functioning.

Science.gov (United States)

Barnes, Andrew D; Jochum, Malte; Mumme, Steffen; Haneda, Noor Farikhah; Farajallah, Achmad; Widarto, Tri Heru; Brose, Ulrich

2014-10-28

Our knowledge about land-use impacts on biodiversity and ecosystem functioning is mostly limited to single trophic levels, leaving us uncertain about whole-community biodiversity-ecosystem functioning relationships. We analyse consequences of the globally important land-use transformation from tropical forests to oil palm plantations. Species diversity, density and biomass of invertebrate communities suffer at least 45% decreases from rainforest to oil palm. Combining metabolic and food-web theory, we calculate annual energy fluxes to model impacts of land-use intensification on multitrophic ecosystem functioning. We demonstrate a 51% reduction in energy fluxes from forest to oil palm communities. Species loss clearly explains variation in energy fluxes; however, this relationship depends on land-use systems and functional feeding guilds, whereby predators are the most heavily affected. Biodiversity decline from forest to oil palm is thus accompanied by even stronger reductions in functionality, threatening to severely limit the functional resilience of communities to cope with future global changes.

Linkages Among Water Vapor Flows, Food Production, and Terrestrial Ecosystem Services

Directory of Open Access Journals (Sweden)

Johan Rockström

1999-12-01

Full Text Available Global freshwater assessments have not addressed the linkages among water vapor flows, agricultural food production, and terrestrial ecosystem services. We perform the first bottom-up estimate of continental water vapor flows, subdivided into the major terrestrial biomes, and arrive at a total continental water vapor flow of 70,000 km3/yr (ranging from 56,000 to 84,000 km3/yr. Of this flow, 90% is attributed to forests, including woodlands (40,000 km3/yr, wetlands (1400 km3/yr, grasslands (15,100 km3/yr, and croplands (6800 km3/yr. These terrestrial biomes sustain society with essential welfare-supporting ecosystem services, including food production. By analyzing the freshwater requirements of an increasing demand for food in the year 2025, we discover a critical trade-off between flows of water vapor for food production and for other welfare-supporting ecosystem services. To reduce the risk of unintentional welfare losses, this trade-off must become embedded in intentional ecohydrological landscape management.

Windage Power Loss in Gas Foil Bearings and the Rotor-Stator Clearance of High Speed Generators Operating in High Pressure Environments

Science.gov (United States)

Bruckner, Robert J.

2009-01-01

Closed Brayton Cycle (CBC) and Closed Supercritical Cycle (CSC) engines are prime candidates to convert heat from a reactor into electric power for robotic space exploration and habitation. These engine concepts incorporate a permanent magnet starter/generator mounted on the engine shaft along with the requisite turbomachinery. Successful completion of the long-duration missions currently anticipated for these engines will require designs that adequately address all losses within the machine. The preliminary thermal management concept for these engine types is to use the cycle working fluid to provide the required cooling. In addition to providing cooling, the working fluid will also serve as the bearing lubricant. Additional requirements, due to the unique application of these microturbines, are zero contamination of the working fluid and entirely maintenance-free operation for many years. Losses in the gas foil bearings and within the rotor-stator gap of the generator become increasingly important as both rotational speed and mean operating pressure are increased. This paper presents the results of an experimental study, which obtained direct torque measurements on gas foil bearings and generator rotor-stator gaps. Test conditions for these measurements included rotational speeds up to 42,000 revolutions per minute, pressures up to 45 atmospheres, and test gases of nitrogen, helium, and carbon dioxide. These conditions provided a maximum test Taylor number of nearly one million. The results show an exponential rise in power loss as mean operating density is increased for both the gas foil bearing and generator windage. These typical "secondary" losses can become larger than the total system output power if conventional design paradigms are followed. A nondimensional analysis is presented to extend the experimental results into the CSC range for the generator windage.

Riverine ecosystem services and the thermoelectric sector: strategic issues facing the Northeastern United States

International Nuclear Information System (INIS)

Miara, Ariel; Vörösmarty, Charles J; Rosenzweig, Bernice; Stewart, Robert J; Wollheim, Wilfred M

2013-01-01

Major strategic issues facing the global thermoelectric sector include environmental regulation, climate change and increasing electricity demand. We have addressed such issues by modeling thermoelectric generation in the Northeastern United States that is reliant on cooling under five sensitivity tests to evaluate losses/gains in power production, thermal pollution and suitable aquatic habitat, comparing the contemporary baseline (2000–2010) with potential future states. Integral to the analysis, we developed a methodology to quantify river water availability for cooling, which we define as an ecosystem service. Projected climate conditions reduce river water available for efficient power plant operations and the river’s capacity to absorb waste heat, causing a loss of regional thermoelectric generation (RTG) (2.5%) in some summers that, compared to the contemporary baseline, is equal to the summertime electricity consumption of 1.3 million Northeastern US homes. Vulnerabilities to warm temperatures and thermal pollution can be alleviated through the use of more efficient natural gas (NG) power plants that have a reduced reliance on cooling water. Conversion of once-through (OT) to cooling tower (CT) systems and the Clean Water Act (CWA) temperature limit regulation, both of which reduce efficiencies at the single plant level, show potential to yield beneficial increases in RTG. This is achieved by obviating the need for large volumes of river water, thereby reducing plant-to-plant interferences through lowering the impact of upstream thermal pollution and preserving a minimum standard of cooling water. The results and methodology framework presented here, which can be extrapolated to other regional assessments with contrasting climates and thermoelectric profiles, can identify opportunities and support decision-making to achieve more efficient energy systems and riverine ecosystem protection. (letter)

Transformation of Digital Ecosystems

DEFF Research Database (Denmark)

Henningsson, Stefan; Hedman, Jonas

2014-01-01

the Digital Ecosystem Technology Transformation (DETT) framework for explaining technology-based transformation of digital ecosystems by integrating theories of business and technology ecosystems. The framework depicts ecosystem transformation as distributed and emergent from micro-, meso-, and macro- level......In digital ecosystems, the fusion relation between business and technology means that the decision of technical compatibility of the offering is also the decision of how to position the firm relative to the coopetive relations that characterize business ecosystems. In this article we develop...... coopetition. The DETT framework consists an alternative to the existing explanations of digital ecosystem transformation as the rational management of one central actor balancing ecosystem tensions. We illustrate the use of the framework by a case study of transformation in the digital payment ecosystem...

Anthropogenic and natural influence on disease prevalence at the humanlivestockwildlife interface in the Serengeti ecosystem, Tanzania

OpenAIRE

Fyumagwa, Robert Dominikus

2012-01-01

Anthropogenic activities in ecosystems interfere with natural processes and cause habitat fragmentation and loss. Habitat fragmentation and loss restrict wildlife movement between populations consequently reducing the gene flow and genetic diversity. Increased human encroachment on wildlife habitat compromises immunity and disturbs host-pathogen relationships resulting in disease outbreaks in naïve populations. Tick-borne and infectious diseases are considered a major threat to the health of ...

Coastal Zone Ecosystem Services: from science to values and decision making; a case study.

Science.gov (United States)

Luisetti, T; Turner, R K; Jickells, T; Andrews, J; Elliott, M; Schaafsma, M; Beaumont, N; Malcolm, S; Burdon, D; Adams, C; Watts, W

2014-09-15

This research is concerned with the following environmental research questions: socio-ecological system complexity, especially when valuing ecosystem services; ecosystems stock and services flow sustainability and valuation; the incorporation of scale issues when valuing ecosystem services; and the integration of knowledge from diverse disciplines for governance and decision making. In this case study, we focused on ecosystem services that can be jointly supplied but independently valued in economic terms: healthy climate (via carbon sequestration and storage), food (via fisheries production in nursery grounds), and nature recreation (nature watching and enjoyment). We also explored the issue of ecosystem stock and services flow, and we provide recommendations on how to value stock and flows of ecosystem services via accounting and economic values respectively. We considered broadly comparable estuarine systems located on the English North Sea coast: the Blackwater estuary and the Humber estuary. In the past, these two estuaries have undergone major land-claim. Managed realignment is a policy through which previously claimed intertidal habitats are recreated allowing the enhancement of the ecosystem services provided by saltmarshes. In this context, we investigated ecosystem service values, through biophysical estimates and welfare value estimates. Using an optimistic (extended conservation of coastal ecosystems) and a pessimistic (loss of coastal ecosystems because of, for example, European policy reversal) scenario, we find that context dependency, and hence value transfer possibilities, vary among ecosystem services and benefits. As a result, careful consideration in the use and application of value transfer, both in biophysical estimates and welfare value estimates, is advocated to supply reliable information for policy making. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Measuring and Modeling the U.S. Regulatory Ecosystem

Science.gov (United States)

Bommarito, Michael J., II; Katz, Daniel Martin

2017-09-01

Over the last 23 years, the U.S. Securities and Exchange Commission has required over 34,000 companies to file over 165,000 annual reports. These reports, the so-called "Form 10-Ks," contain a characterization of a company's financial performance and its risks, including the regulatory environment in which a company operates. In this paper, we analyze over 4.5 million references to U.S. Federal Acts and Agencies contained within these reports to measure the regulatory ecosystem, in which companies are organisms inhabiting a regulatory environment. While individuals across the political, economic, and academic world frequently refer to trends in this regulatory ecosystem, far less attention has been paid to supporting such claims with large-scale, longitudinal data. In this paper, in addition to positing a model of regulatory ecosystems, we document an increase in the regulatory energy per filing, i.e., a warming "temperature." We also find that the diversity of the regulatory ecosystem has been increasing over the past two decades. These findings support the claim that regulatory activity and complexity are increasing, and this framework contributes an important step towards improving academic and policy discussions around legal complexity and regulation.

ANALYSIS OF OPTIMUM OPERATING MODES OF POWER TRANSFORMERS UNDER OPERATING CONDITIONS

Directory of Open Access Journals (Sweden)

I. V. Khomenko

2016-12-01

Full Text Available Purpose. The study of parallel operation optimal modes of transformer equipment for a variety of operating conditions: same or different types of transformers, with or without reactive power flows. Methodology. Losses of energy in transformers make 30 % of all losses. Therefore the choice of the economically justified parallel operation of transformers is effective action to reduce losses. Typically, in the calculations of reactive power flows in the transformers are not taken into account. It is interesting to analyze the optimal operating conditions of transformers with and without reactive power flows. Results. Calculations for transformers in distribution networks showed that the inclusion of reactive power flows in transformers significant impact on the calculated optimum regimes of transformers.

Wetland Loss Patterns and Inundation-Productivity ...

Science.gov (United States)

Tidal salt marsh is a key defense against, yet is especially vulnerable to, the effects of accelerated sea level rise. To determine whether salt marshes in southern New England will be stable given increasing inundation over the coming decades, we examined current loss patterns, inundation-productivity feedbacks, and sustaining processes. A multi-decadal analysis of salt marsh aerial extent using historic imagery and maps revealed that salt marsh vegetation loss is both widespread and accelerating, with vegetation loss rates over the past four decades summing to 17.3 %. Landward retreat of the marsh edge, widening and headward expansion of tidal channel networks, loss of marsh islands, and the development and enlargement of interior depressions found on the marsh platform contributed to vegetation loss. Inundation due to sea level rise is strongly suggested as a primary driver: vegetation loss rates were significantly negatively correlated with marsh elevation (r2 = 0.96; p = 0.0038), with marshes situated below mean high water (MHW) experiencing greater declines than marshes sitting well above MHW. Growth experiments with Spartina alterniflora, the Atlantic salt marsh ecosystem dominant, across a range of elevations and inundation regimes further established that greater inundation decreases belowground biomass production of S. alterniflora and, thus, negatively impacts organic matter accumulation. These results suggest that southern New England salt ma

The impact of shrimp farming on mangrove ecosystems

DEFF Research Database (Denmark)

Ashton, Elizabeth Clare

2008-01-01

. Policy to position shrimp farms behind mangroves can be effective but also requires good institutional capacity and coordination, effective enforcement, incentives, land tenure and participation of all stakeholders for success. Better management practices have been identified which reduce impacts......Farmed shrimp production and value continue to increase with Asia producing the global majority of shrimp and the USA, Japan and Europe being the main importers. Shrimp farming systems are very diverse in their management, size and impacts. There are many causes for mangrove loss but the conversion...... of mangroves to shrimp farms has caused considerable attention. The major issues of shrimp farming include the loss of important ecological and socio-economic functions of mangrove ecosystems, changes in hydrology, salinization, introduction of non-native species and diseases, pollution from effluents...

Searching for resilience: addressing the impacts of changing disturbance regimes on forest ecosystem services

Science.gov (United States)

Seidl, Rupert; Spies, Thomas A.; Peterson, David L.; Stephens, Scott L.; Hicke, Jeffrey A.

2016-01-01

Summary 1. The provisioning of ecosystem services to society is increasingly under pressure from global change. Changing disturbance regimes are of particular concern in this context due to their high potential impact on ecosystem structure, function and composition. Resilience-based stewardship is advocated to address these changes in ecosystem management, but its operational implementation has remained challenging. 2. We review observed and expected changes in disturbance regimes and their potential impacts on provisioning, regulating, cultural and supporting ecosystem services, concentrating on temperate and boreal forests. Subsequently, we focus on resilience as a powerful concept to quantify and address these changes and their impacts, and present an approach towards its operational application using established methods from disturbance ecology. 3. We suggest using the range of variability concept – characterizing and bounding the long-term behaviour of ecosystems – to locate and delineate the basins of attraction of a system. System recovery in relation to its range of variability can be used to measure resilience of ecosystems, allowing inferences on both engineering resilience (recovery rate) and monitoring for regime shifts (directionality of recovery trajectory). 4. It is important to consider the dynamic nature of these properties in ecosystem analysis and management decision-making, as both disturbance processes and mechanisms of resilience will be subject to changes in the future. Furthermore, because ecosystem services are at the interface between natural and human systems, the social dimension of resilience (social adaptive capacity and range of variability) requires consideration in responding to changing disturbance regimes in forests. 5. Synthesis and applications. Based on examples from temperate and boreal forests we synthesize principles and pathways for fostering resilience to changing disturbance regimes in ecosystem management. We

[Impacts of hydroelectric cascade exploitation on river ecosystem and landscape: a review].

Science.gov (United States)

Yang, Kun; Deng, Xi; Li, Xue-Ling; Wen, Ping

2011-05-01

Hydroelectric cascade exploitation, one of the major ways for exploiting water resources and developing hydropower, not only satisfies the needs of various national economic sectors, but also promotes the socio-economic sustainable development of river basin. unavoidable anthropogenic impacts on the entire basin ecosystem. Based on the process of hydroelectric cascade exploitation and the ecological characteristics of river basins, this paper reviewed the major impacts of hydroelectric cascade exploitation on dam-area ecosystems, river reservoirs micro-climate, riparian ecosystems, river aquatic ecosystems, wetlands, and river landscapes. Some prospects for future research were offered, e.g., strengthening the research of chain reactions and cumulative effects of ecological factors affected by hydroelectric cascade exploitation, intensifying the study of positive and negative ecological effects under the dam networks and their joint operations, and improving the research of successional development and stability of basin ecosystems at different temporal and spatial scales.

Mapping cultural ecosystem services: A framework to assess the potential for outdoor recreation across the EU

NARCIS (Netherlands)

Paracchini, M.L.; Zulian, G.; Kopperoinen, L.; Maes, J.; Schagner, J.P.; Termansen, M.; Zandersen, M.; Perez-Soba, M.; Scholefield, P.A.; Bidoglio, G.

2014-01-01

Research on ecosystem services mapping and valuing has increased significantly in recent years. However, compared to provisioning and regulating services, cultural ecosystem services have not yet been fully integrated into operational frameworks. One reason for this is that transdisciplinarity is

Icefield-to-ocean linkages across the northern Pacific coastal temperate rainforest ecosystem

Science.gov (United States)

O'Neel, Shad; Hood, Eran; Bidlack, Allison L.; Fleming, Sean W.; Arimitsu, Mayumi L.; Arendt, Anthony; Burgess, Evan W.; Sergeant, Christopher J.; Beaudreau, Anne E.; Timm, Kristin; Hayward, Gregory D.; Reynolds, Joel H.; Pyare, Sanjay

2015-01-01

Rates of glacier mass loss in the northern Pacific coastal temperate rainforest (PCTR) are among the highest on Earth, and changes in glacier volume and extent will affect the flow regime and chemistry of coastal rivers, as well as the nearshore marine ecosystem of the Gulf of Alaska. Here we synthesize physical, chemical and biological linkages that characterize the northern PCTR ecosystem, with particular emphasis on the potential impacts of glacier change in the coastal mountain ranges on the surface–water hydrology, biogeochemistry, coastal oceanography and aquatic ecology. We also evaluate the relative importance and interplay between interannual variability and long-term trends in key physical drivers and ecological responses. To advance our knowledge of the northern PCTR, we advocate for cross-disciplinary research bridging the icefield-to-ocean ecosystem that can be paired with long-term scientific records and designed to inform decisionmakers.

Gauging leaf-level contributions to landscape-level water loss within a Western US dryland fores

Science.gov (United States)

Murphy, P.; Potts, D. L.; Minor, R. L.; Hamerlynck, E. P.; Sutter, L., Jr.; Barron-Gafford, G.

2017-12-01

Western US forests represent a large constituent of the North American water and carbon cycles, yet the primary controls on water loss from these ecosystems remains unknown. In dryland forests, such as those found in the Southwestern US, water availability is key to ecosystem function, and the timing and magnitude of water loss can have lasting effects on the health of these communities. One poorly defined part of the water balance in these forests is the partitioning of evapotranspiration (ET) into evaporation (E; blue flow) to transpiration (T; green flow). A study of water fluxes at multiple scales in a semiarid montane forest in Southern Arizona speaks to the partitioning of these two water flows. Within the footprint of an eddy covariance system, which estimates ecosystem ET, we have examined the impacts of variation in climate, species makeup, and topographic position on E and T. This was done using leaf-level measures of T, pedon-scale measures of E, and whole-tree water loss by way of sap flux sensors. Where available, we have examined E, T, and ET fluxes across multiple seasons and years of highly variable precipitation records. Understanding the partitioning of ET is crucial, considering that projected changes to dryland ecosystems include longer periods of drought separated by heavier precipitation events. At a moment when potential impacts of changing climate on dryland structure and function are poorly understood, a stronger comprehension of these blue and green water flows is necessary to forecast the productivity of Western US forests into the future.

Timing anthropogenic stressors to mitigate their impact on marine ecosystem resilience

OpenAIRE

Wu, Paul Pao-Yen; Mengersen, Kerrie; McMahon, Kathryn; Kendrick, Gary A.; Chartrand, Kathryn; York, Paul H.; Rasheed, Michael A.; Caley, M. Julian

2017-01-01

Better mitigation of anthropogenic stressors on marine ecosystems is urgently needed to address increasing biodiversity losses worldwide. We explore opportunities for stressor mitigation using whole-of-systems modelling of ecological resilience, accounting for complex interactions between stressors, their timing and duration, background environmental conditions and biological processes. We then search for ecological windows, times when stressors minimally impact ecological resilience, defined...

Farm management, not soil microbial diversity, controls nutrient loss from smallholder tropical agriculture

Directory of Open Access Journals (Sweden)

Stephen A Wood

2015-03-01

Full Text Available Tropical smallholder agriculture supports the livelihoods of over 900 million of the world’s poorest people. This form of agriculture is undergoing rapid transformation in nutrient cycling pathways as international development efforts strongly promote greater use of mineral fertilizers to increase crop yields. These changes in nutrient availability may alter the composition of microbial communities with consequences for rates of biogeochemical processes that control nutrient losses to the environment. Ecological theory suggests that altered microbial diversity will strongly influence processes performed by relatively few microbial taxa, such as denitrification and hence nitrogen losses as nitrous oxide, a powerful greenhouse gas. Whether this theory helps predict nutrient losses from agriculture depends on the relative effects of microbial community change and increased nutrient availability on ecosystem processes. We find that mineral and organic nutrient addition to smallholder farms in Kenya alters the taxonomic and functional diversity of soil microbes. However, we find that the direct effects of farm management on both denitrification and carbon mineralization are greater than indirect effects through changes in the taxonomic and functional diversity of microbial communities. Changes in functional diversity are strongly coupled to changes in specific functional genes involved in denitrification, suggesting that it is the expression, rather than abundance, of key functional genes that can serve as an indicator of ecosystem process rates. Our results thus suggest that widely used broad summary statistics of microbial diversity based on DNA may be inappropriate for linking microbial communities to ecosystem processes in certain applied settings. Our results also raise doubts about the relative control of microbial composition compared to direct effects of management on nutrient losses in applied settings such as tropical agriculture.

Activation of the marine ecosystem model 3D CEMBS for the Baltic Sea in operational mode

Science.gov (United States)

Dzierzbicka-Glowacka, Lidia; Jakacki, Jaromir; Janecki, Maciej; Nowicki, Artur

2013-04-01

The paper presents a new marine ecosystem model 3D CEMBS designed for the Baltic Sea. The ecosystem model is incorporated into the 3D POPCICE ocean-ice model. The Current Baltic Sea model is based on the Community Earth System Model (CESM from the National Center for Atmospheric Research) which was adapted for the Baltic Sea as a coupled sea-ice model. It consists of the Community Ice Code (CICE model, version 4.0) and the Parallel Ocean Program (version 2.1). The ecosystem model is a biological submodel of the 3D CEMBS. It consists of eleven mass conservation equations. There are eleven partial second-order differential equations of the diffusion type with the advective term for phytoplankton, zooplankton, nutrients, dissolved oxygen, and dissolved and particulate organic matter. This model is an effective tool for solving the problem of ecosystem bioproductivity. The model is forced by 48-hour atmospheric forecasts provided by the UM model from the Interdisciplinary Centre for Mathematical and Computational Modelling of Warsaw University (ICM). The study was financially supported by the Polish State Committee of Scientific Research (grants: No N N305 111636, N N306 353239). The partial support for this study was also provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBaltyk founded by European Union through European Regional Development Fund contract no. POIG 01.01.02-22-011/09. Calculations were carried out at the Academy Computer Centre in Gdańsk.

Organism-Sediment Interactions Govern Post-Hypoxia Recovery of Ecosystem Functioning

Science.gov (United States)

Van Colen, Carl; Rossi, Francesca; Montserrat, Francesc; Andersson, Maria G. I.; Gribsholt, Britta; Herman, Peter M. J.; Degraer, Steven; Vincx, Magda; Ysebaert, Tom; Middelburg, Jack J.

2012-01-01

Hypoxia represents one of the major causes of biodiversity and ecosystem functioning loss for coastal waters. Since eutrophication-induced hypoxic events are becoming increasingly frequent and intense, understanding the response of ecosystems to hypoxia is of primary importance to understand and predict the stability of ecosystem functioning. Such ecological stability may greatly depend on the recovery patterns of communities and the return time of the system properties associated to these patterns. Here, we have examined how the reassembly of a benthic community contributed to the recovery of ecosystem functioning following experimentally-induced hypoxia in a tidal flat. We demonstrate that organism-sediment interactions that depend on organism size and relate to mobility traits and sediment reworking capacities are generally more important than recovering species richness to set the return time of the measured sediment processes and properties. Specifically, increasing macrofauna bioturbation potential during community reassembly significantly contributed to the recovery of sediment processes and properties such as denitrification, bedload sediment transport, primary production and deep pore water ammonium concentration. Such bioturbation potential was due to the replacement of the small-sized organisms that recolonised at early stages by large-sized bioturbating organisms, which had a disproportionately stronger influence on sediment. This study suggests that the complete recovery of organism-sediment interactions is a necessary condition for ecosystem functioning recovery, and that such process requires long periods after disturbance due to the slow growth of juveniles into adult stages involved in these interactions. Consequently, repeated episodes of disturbance at intervals smaller than the time needed for the system to fully recover organism-sediment interactions may greatly impair the resilience of ecosystem functioning. PMID:23185440

Land Use in LCA: Including Regionally Altered Precipitation to Quantify Ecosystem Damage.

Science.gov (United States)

Lathuillière, Michael J; Bulle, Cécile; Johnson, Mark S

2016-11-01

The incorporation of soil moisture regenerated by precipitation, or green water, into life cycle assessment has been of growing interest given the global importance of this resource for terrestrial ecosystems and food production. This paper proposes a new impact assessment model to relate land and water use in seasonally dry, semiarid, and arid regions where precipitation and evapotranspiration are closely coupled. We introduce the Precipitation Reduction Potential midpoint impact representing the change in downwind precipitation as a result of a land transformation and occupation activity. Then, our end-point impact model quantifies terrestrial ecosystem damage as a function of precipitation loss using a relationship between woody plant species richness, water and energy regimes. We then apply the midpoint and end-point models to the production of soybean in Southeastern Amazonia which has resulted from the expansion of cropland into tropical forest, with noted effects on local precipitation. Our proposed cause-effect chain represents a complementary approach to previous contributions which have focused on water consumption impacts and/or have represented evapotranspiration as a loss to the water cycle.

Biodiversity and ecosystem functioning in evolving food webs.

Science.gov (United States)

Allhoff, K T; Drossel, B

2016-05-19

We use computer simulations in order to study the interplay between biodiversity and ecosystem functioning (BEF) during both the formation and the ongoing evolution of large food webs. A species in our model is characterized by its own body mass, its preferred prey body mass and the width of its potential prey body mass spectrum. On an ecological time scale, population dynamics determines which species are viable and which ones go extinct. On an evolutionary time scale, new species emerge as modifications of existing ones. The network structure thus emerges and evolves in a self-organized manner. We analyse the relation between functional diversity and five community level measures of ecosystem functioning. These are the metabolic loss of the predator community, the total biomasses of the basal and the predator community, and the consumption rates on the basal community and within the predator community. Clear BEF relations are observed during the initial build-up of the networks, or when parameters are varied, causing bottom-up or top-down effects. However, ecosystem functioning measures fluctuate only very little during long-term evolution under constant environmental conditions, despite changes in functional diversity. This result supports the hypothesis that trophic cascades are weaker in more complex food webs. © 2016 The Author(s).

Above and belowground controls on litter decomposition in semiarid ecosystems: effects of solar radiation, water availability and litter quality

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Austin, A. T.; Araujo, P. I.; Leva, P. E.; Ballare, C. L.

2008-12-01

The integrated controls on soil organic matter formation in arid and semiarid ecosystems are not well understood and appear to stem from a number of interacting controls affecting above- and belowground carbon turnover. While solar radiation has recently been shown to have an important direct effect on carbon loss in semiarid ecosystems as a result of photochemical mineralization of aboveground plant material, the mechanistic basis for photodegradative losses is poorly understood. In addition, there are large potential differences in major controls on above- and belowground decomposition in low rainfall ecosystems. We report on a mesocosm and field study designed to examine the relative importance of different wavelengths of solar radiation, water availability, position of senescent material above- and belowground and the importance of carbon litter quality in determining rates of abiotic and biotic decomposition. In a factorial experiment of mesocosms, we incubated leaf and root litter simultaneously above- and belowground and manipulated water availability with large and small pulses. Significant interactions between position-litter type and position-pulse sizes demonstrated interactive controls on organic mass loss. Aboveground decomposition showed no response to pulse size or litter type, as roots and leaves decomposed equally rapidly under all circumstances. In contrast, belowground decomposition was significantly altered by litter type and water pulses, with roots decomposing significantly slower and small water pulses reducing belowground decomposition. In the field site, using plastic filters which attenuated different wavelengths of natural solar radiation, we found a highly significant effect of radiation exclusion on mass loss and demonstrated that both UV-A and short-wave visible light can have important impacts on photodegradative carbon losses. The combination of position and litter quality effects on litter decomposition appear to be critical for the

Prairie strips improve biodiversity and the delivery of multiple ecosystem services from corn-soybean croplands

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Losses of biodiversity and ecosystem services from industrial agricultural lands are persistent and growing challenges in the United States despite decades of spending on natural resource management. Most investments have been targeted toward engineered practices (e.g., sediment control basins, terr...

High carbon losses due to recent cropland expansion in the United States

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Spawn, S.; Lark, T.; Gibbs, H.

2017-12-01

Land conversion for agriculture in the United States has reached record highs in recent years. From 2008 to 2012 nearly 30,000 square kilometers of previously un-cultivated land were converted to agricultural land use with much of this expansion occurring on grasslands (77%) and shrublands (8%). To understand the effects of this conversion on global C cycling, we created novel, spatially explicit biomass maps for these biomes by combining existing satellite data products with models derived from field measurements. We then estimated changes in existing C stocks by combining our derived data with existing Landsat-scale data on land cover, land conversion, forest biomass and soil organic carbon (C) stocks. We find that conversion results in annual C losses of approximately 25 Tg C from US terrestrial ecosystems. Nationwide, roughly 80% of total emissions result from committed soil organic C losses. While biomass losses from expansion into forests and wetlands are disproportionately high per unit area, the vast majority of C losses occurred in grassland ecosystems, with grassland roots representing close to 70% of total biomass losses across all biomes. C losses are partially offset each year by agricultural abandonment which we estimate could sequester as much as 15 Tg C, annually. Taken together, we find that US agricultural expansion results in net annual emissions of 10 Tg C which is nearly 30% of emissions from existing US croplands. Our estimate is comparable to a recent analogous estimate for conversion of the Brazilian Cerrado and is equivalent to 10% of annual C losses from pantropical deforestation, suggesting that the effects of US cropland expansion could be globally significant.

The EBM-DPSER conceptual model: integrating ecosystem services into the DPSIR framework.

Directory of Open Access Journals (Sweden)

Christopher R Kelble

Full Text Available There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society

The EBM-DPSER Conceptual Model: Integrating Ecosystem Services into the DPSIR Framework

Science.gov (United States)

Kelble, Christopher R.; Loomis, Dave K.; Lovelace, Susan; Nuttle, William K.; Ortner, Peter B.; Fletcher, Pamela; Cook, Geoffrey S.; Lorenz, Jerry J.; Boyer, Joseph N.

2013-01-01

There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR) conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER) conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society and does so within

Ecosystem degradation in India

International Nuclear Information System (INIS)

Sinha, B.N.

1990-01-01

Environmental and ecosystem studies have assumed greater relevance in the last decade of the twentieth century than even before. The urban settlements are becoming over-crowded and industries are increasingly polluting the air, water and sound in our larger metropolises. Degradation of different types of ecosystem are discussed in this book, Ecosystem Degradation in India. The book has been divided into seven chapters: Introduction, Coastal and Delta Ecosystem, River Basin Ecosystem, Mountain Ecosystem, Forest Ecosystem, Urban Ecosystem and the last chapter deals with the Environmental Problems and Planning. In the introduction the environmental and ecosystem degradation problems in India is highlighted as a whole while in other chapters mostly case studies by experts who know their respective terrain very intimately are included. The case study papers cover most part of India and deal with local problems, stretching from east coast to west coast and from Kashmir to Kanyakumari. (author)

Addressing the Multiple Drivers of Wetland Ecosystems Degradation in Lagos, Nigeria

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Agboola, J.; Ndimele, P. E.; Odunuga, S.; Akanni, A.; Kosemani, B.; Ahove, M.

2015-12-01

Several body of knowledge have noted the importance of wetland ecosystems in climate moderation, resource supply and flood risk reduction amongst others. Relevant as it may, rapidly increasing population and uncontrolled urban development poses a challenge in some regions and require understanding of the ecosystem components and drivers of change over a long period of time. Thus, the main thrust of this paper is to analyse multiple drivers of wetland ecosystems degradation in the last 30 years in the Lagos megacity using field study, desktop review, satellite data and laboratory analysis. Key drivers identified includes: conversion of wetlands to settlements and waste sink, land use planning that neglects wetland conservation and restoration, ineffective legal status for wetlands, over exploitation leading to degradation and fragmentation of wetland ecosystems governance. In stemming further loss of this vital ecosystem, this study adopted and proposed respectively, the Drivers, Pressure, State, Impact and Response (DPSIR) and Integrated Planning Approach (IPA) frameworks in analysing policy and governance issues in wetland development. These analyses figured out amongst others, strict conservation and sustainable use of wetland resources, habitat restoration, climate adaptation measures, legal protection and wetland management institution as major responses to current multiple pressures facing wetland ecosystems in Lagos. For these frameworks to be made meaningful, weak coordination among government agencies and institutional capacity in implementation and law enforcement, unsustainable resource extraction by private/business organization and issues on alternative sources of income on the part of the local communities amongst others needs to be addressed.

Biophysical and sociocultural factors underlying spatial trade-offs of ecosystem services in semiarid watersheds

Directory of Open Access Journals (Sweden)

Marina García-Llorente

2015-09-01

Full Text Available Biophysical and social systems are linked to form social-ecological systems whose sustainability depends on their capacity to absorb uncertainty and cope with disturbances. In this study, we explored the key biophysical and socio-cultural factors underlying ecosystem service supply in two semiarid watersheds of southern Spain. These included variables associated with the role that freshwater flows and biodiversity play in securing the system's capacity to sustain essential ecosystem services and their relationship with social demand for services, local water governance, and land-use intensification. Our results reveal the importance of considering the invisible dimensions of water and biodiversity, i.e. green freshwater flows and trait-based indicators, because of their relevance to the supply of ecosystem services. Furthermore, they uncover the importance of traditional irrigation canals, a local water governance system, in maintaining the ecosystems' capacity to supply services. The study also highlights the complex trade-offs that occur because of the spatial mismatch between ecosystem service supply (upstream and ecosystem service demand (downstream in watersheds. Finally, we found that land-use intensification generally resulted in losses of the biophysical factors that underpin the supply of some ecosystem services, increases in social demand for less diversified services, and the abandonment of local governance practices. Attempts to manage social-ecological systems toward sustainability at the local scale should identify the key biophysical and socio-cultural factors that are essential for maintaining ecosystem services and should recognize existing interrelationships between them. Land-use management should also take into account ecosystem service trade-offs and the consequences resulting from land-use intensification.

Response of ecosystem services to land use change in Xiamen Island

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Gao, L.

2009-12-01

: Land use change was a major factor affecting ecosystem services. Taken Xiamen Island as an example, by integrating remote sensing data to examine land use patterns from 1950 to 2007, the regional ecosystem services of Xiamen Island were evaluated based on two revised methods aiming to identify the stress effects and mechanisms of land use change on ecosystem services. The results showed that during 1950~2007, in general, Xiamen Island’s land use intensity had been annually rising. The trends of Xiamen Island’s ecosystem services value acquired by two methods were both consistent with decreasing along with the growth of land use intensity. Before 1987, the ecosystem service value of Xiamen Island had increased by 1.07 million yuan, due to the expanding of 12.87 km2 water and wetland. After the establishment of Xiamen special economic zone in 1984, the rapid urbanization has resulted a sharp decline in ecosystem service value, the average annual loss reached by 619,773 yuan after 1987. As the utilization of land reaching saturation and the launching of ecological projects, such as the Xiamen Eastern Sea Comprehensive Improvement Project, it could be predicted that the decreasing trend of ecosystem services value was going to be slowed down in the near future. The first revised method referencing four eco-system services solved the problem of overestimated value caused by the second revised method based on provisioning service alone. By applying the ESV total correction method, the problem of over counting service value by correction made from a single aspect could be solved.Equivalent value per unit area of ecosystem services in China 2007 and revised value by second method Note: The modified coefficient of crop, orchard & forest, wetland and inland water provisioning ESV revised by the second method is 2.858, 2.405, 1.523, 1.843 respectively; for regulating, ultural and supporting ESV, the coefficient is 2.339, 15.339, 2.339 respectively.

Landowner behavior can determine the success of conservation strategies for ecosystem migration under sea-level rise.

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Field, Christopher R; Dayer, Ashley A; Elphick, Chris S

2017-08-22

The human aspects of conservation are often overlooked but will be critical for identifying strategies for biological conservation in the face of climate change. We surveyed the behavioral intentions of coastal landowners with respect to various conservation strategies aimed at facilitating ecosystem migration for tidal marshes. We found that several popular strategies, including conservation easements and increasing awareness of ecosystem services, may not interest enough landowners to allow marsh migration at the spatial scales needed to mitigate losses from sea-level rise. We identified less common conservation strategies that have more support but that are unproven in practice and may be more expensive. Our results show that failure to incorporate human dimensions into ecosystem modeling and conservation planning could lead to the use of ineffective strategies and an overly optimistic view of the potential for ecosystem migration into human dominated areas.

Connecting above and below: the impacts of large wildlife loss and pastoralism on savanna carbon dynamics

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Forbes, E. S.; Young, H. S.; Young, T.; Schimel, J.

2016-12-01

There is widespread evidence that large wildlife species contribute to ecosystem carbon efflux; however, their influence is not incorporated into traditional carbon models. As large wildlife loss continues in the Anthropocene and in the face of climate change, it becomes increasingly important to understand the impacts of their loss on ecosystem carbon. The charismatic, threatened wildlife in central Kenya's savanna provide an ideal framework for these questions. We compared differences in carbon efflux in the presence or absence of native herbivores and/or cattle, as a proxy for wildlife loss and the interaction of pastoralism. We measured carbon dynamics in situ with a closed-chamber system and microbial respiration rates in lab by incubating sampled soil. We discovered a significant effect of herbivore presence/absence on carbon efflux: incubated soils collected from plots with cattle only exhibit greater carbon accumulation and faster initial respiration rates than soils collected from plots with native herbivores and no cattle, native herbivores and cattle, and neither native herbivores nor cattle. When measured in situ, plots with no herbivores show higher efflux than plots with only native herbivores, and plots with both. The data also suggest that grazing pressure results in successively lower efflux. The differences in these studies imply that the impacts of large wildlife loss differ on microbial respiration as an isolated mechanism in ecosystem carbon exchange, and total carbon efflux. This is most likely because in situ efflux measurements encompass environmental variables as well as soil microbial respiration. The lab data suggest that cattle as the only herbivore causes greater soil microbial efflux compared to native herbivores alone, native herbivores with cattle, or no herbivores. The in situ data show that no herbivores results in increased carbon efflux, and suggest that increasing numbers of herbivores lowers efflux.These studies demonstrate

A Regional Multi-permit Market for Ecosystem Services

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Bernknopf, R.; Amos, P.; Zhang, E.

2014-12-01

Regional cap and trade programs have been in operation since the 1970's to reduce environmental externalities (NOx and SOx emissions) and have been shown to be beneficial. Air quality and water quality limits are enforced through numerous Federal and State laws and regulations while local communities are seeking ways to protect regional green infrastructure and their ecosystems services. Why not combine them in a market approach to reduce many environmental externalities simultaneously? In a multi-permit market program reforestation (land offsets) as part of a nutrient or carbon sequestration trading program would provide a means to reduce agrochemical discharges into streams, rivers, and groundwater. Land conversions also improve the quality and quantity of other environmental externalities such as air pollution. Collocated nonmarket ecosystem services have societal benefits that can expand the crediting system into a multi-permit trading program. At a regional scale it is possible to combine regulation of water quality, air emissions and quality, and habitat conservation and restoration into one program. This research is about the economic feasibility of a Philadelphia regional multi-permit (cap and trade) program for ecosystem services. Instead of establishing individual markets for ecosystem services, the assumption of the spatial portfolio approach is that it is based on the interdependence of ecosystem functions so that market credits encompasses a range of ecosystem services. Using an existing example the components of the approach are described in terms of scenarios of land portfolios and the calculation of expected return on investment and risk. An experiment in the Schuylkill Watershed will be described for ecosystem services such as nutrients in water and populations of bird species along with Green House Gases. The Philadelphia regional market includes the urban - nonurban economic and environmental interactions and impacts.

Evaluation of Environmental Quality Productive Ecosystem Guayas (Ecuador).

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Pozo, Wilson; Pardo, Francisco; Sanfeliu, Teófilo; Carrera, Gloria; Jordan, Manuel; Bech, Jaume; Roca, Núria

2015-04-01

Natural resources are deteriorating very rapidly in the Gulf of Guayaquil and the area of influence in the Guayas Basin due to human activity. Specific problems are generated by the mismanagement of the aquaculture industry affecting the traditional agricultural sectors: rice, banana, sugarcane, cocoa, coffee, and soya also studied, and by human and industrial settlements. The development of industrial activities such as aquaculture (shrimp building for shrimp farming in ponds) and agriculture, have increasingly contributed to the generation of waste, degrading and potentially toxic elements in high concentrations, which can have adverse effects on organisms in the ecosystems, in the health of the population and damage the ecological and environmental balance. The productive Guayas ecosystem, consists of three interrelated ecosystems, the Gulf of Guayaquil, the Guayas River estuary and the Guayas Basin buffer. The objective of this study was to evaluate the environmental quality of the productive Guayas ecosystem (Ecuador), through operational and specific objectives: 1) Draw up the transition coastal zone in the Gulf of Guayaquil, 2) Set temporal spatial variability of soil salinity in wetlands rice, Lower Guayas Basin, 3) evaluate the heavy metals in wetland rice in the Lower Basin of Guayas. The physical and chemical parameters of the soils have been studied. These are indicators of environmental quality. The multivariate statistical method showed the relations of similarities and dissimilarities between variables and parameter studies as stable. Moreover, the boundaries of coastal transition areas, temporal spatial variability of soil salinity and heavy metals in rice cultivation in the Lower Basin of Guayas were researched. The sequential studies included and discussed represent a broad framework of fundamental issues that has been valued as a basic component of the productive Guayas ecosystem. They are determinants of the environmental quality of the Guayas

Climate, ecosystems, and planetary futures: The challenge to predict life in Earth system models.

Science.gov (United States)

Bonan, Gordon B; Doney, Scott C

2018-02-02

Many global change stresses on terrestrial and marine ecosystems affect not only ecosystem services that are essential to humankind, but also the trajectory of future climate by altering energy and mass exchanges with the atmosphere. Earth system models, which simulate terrestrial and marine ecosystems and biogeochemical cycles, offer a common framework for ecological research related to climate processes; analyses of vulnerability, impacts, and adaptation; and climate change mitigation. They provide an opportunity to move beyond physical descriptors of atmospheric and oceanic states to societally relevant quantities such as wildfire risk, habitat loss, water availability, and crop, fishery, and timber yields. To achieve this, the science of climate prediction must be extended to a more multifaceted Earth system prediction that includes the biosphere and its resources. Copyright © 2018, American Association for the Advancement of Science.

Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity

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Pellegrini, Adam F. A.; Ahlström, Anders; Hobbie, Sarah E.; Reich, Peter B.; Nieradzik, Lars P.; Staver, A. Carla; Scharenbroch, Bryant C.; Jumpponen, Ari; Anderegg, William R. L.; Randerson, James T.; Jackson, Robert B.

2018-01-01

Fire frequency is changing globally and is projected to affect the global carbon cycle and climate. However, uncertainty about how ecosystems respond to decadal changes in fire frequency makes it difficult to predict the effects of altered fire regimes on the carbon cycle; for instance, we do not fully understand the long-term effects of fire on soil carbon and nutrient storage, or whether fire-driven nutrient losses limit plant productivity. Here we analyse data from 48 sites in savanna grasslands, broadleaf forests and needleleaf forests spanning up to 65 years, during which time the frequency of fires was altered at each site. We find that frequently burned plots experienced a decline in surface soil carbon and nitrogen that was non-saturating through time, having 36 per cent (±13 per cent) less carbon and 38 per cent (±16 per cent) less nitrogen after 64 years than plots that were protected from fire. Fire-driven carbon and nitrogen losses were substantial in savanna grasslands and broadleaf forests, but not in temperate and boreal needleleaf forests. We also observe comparable soil carbon and nitrogen losses in an independent field dataset and in dynamic model simulations of global vegetation. The model study predicts that the long-term losses of soil nitrogen that result from more frequent burning may in turn decrease the carbon that is sequestered by net primary productivity by about 20 per cent of the total carbon that is emitted from burning biomass over the same period. Furthermore, we estimate that the effects of changes in fire frequency on ecosystem carbon storage may be 30 per cent too low if they do not include multidecadal changes in soil carbon, especially in drier savanna grasslands. Future changes in fire frequency may shift ecosystem carbon storage by changing soil carbon pools and nitrogen limitations on plant growth, altering the carbon sink capacity of frequently burning savanna grasslands and broadleaf forests.

Changes in ecosystem service values in Zhoushan Island using remote sensing time series data

Science.gov (United States)

Zhang, Xiaoping; Qin, Yanpei; Lv, Ying; Zhen, Guangwei; Gong, Fang; Li, Chaokui

2017-10-01

The largest inhabited island, Zhoushan Island, is the center of economy, culture, shipping, and fishing in the Zhoushan Archipelago New Area. Its coastal wetland and tidal flats offer significant ecological services including floodwater storage, wildlife habitat, and buffers against tidal surges. Yet, large-scale land reclamation and new land development may dramatically change ecosystem services. In this research, we assess changes in ecosystem service values in Zhoushan Island during 1990-2000-2011. Three LANDSAT TM and/or ETM data sets were used to determine the spatial pattern of land use, and previously published value coefficients were used to calculate the ecosystem service values delivered by each land category. The results show that total value of ecosystem services in Zhoushan Island declined by 11% from 2920.07 billion Yuan to 2609.77 billion Yuan per year between 1990 and 2011. This decrease is largely attributable to the 51% loss of tidal flats. The combined ecosystem service values of woodland, paddy land and tidal flats were over 90% of the total values. The result indicates that future land-use policy should pay attention to the conservation of these ecosystems over uncontrolled reclamation and coastal industrial development, and that further coastal reclamation should be on rigorous environmental impact analyses.

Silvicultural operation on the forest ecosystems: Methodology for forest hydrological monitoring; Effetti del taglio sugli ecosistemi forestali in ambiente montamo: Proposte metologiche per il monitoraggio dell`idrologia forestale

Energy Technology Data Exchange (ETDEWEB)

Andreotti, A; Collina, M; Serra, F; Naviglio, L [ENEA, Centro Ricerche Brasimone, Bologna (Italy). Dipt. Ambiente; Bonora, P [ENEA, Centro Ricerche ` E. Clementel` , Bologna (Italy). Dipt. Ambiente; Gregori, E; Napoli, R [Istituto Sperimentale per lo Studio e la Difesa del Suolo, Firenze (Italy)

1997-03-01

During 1994, Ente Nazionale per l`Energia Elettrica, with the contribution of the Ministry of Agricultural, Alimentary and Forest Resources, started a research program to assess the effects of the silvicultural operations on the forest ecosystems, investigating particularly the hydrological aspects, the erosion and the nutrient cycle. The research must monitor two forest plots coinciding with two secondary watersheds in the Torto stream valley (Northern Italy - high Bolognan Appennines) during about ten years. One plot will be let naturally evolve, while the other one, after a period of 3-5 years, must be subject to a cut; the comparison between the two plots will allow us to evaluate the nature and the size of the changes induced in the ecosystem by man through the silvicultural operations. Because of the complexity of the environmental parameters the authors want to study, initially it was necessary to determine methodology and instruments required for attaining the set goals. In this technical report are shown the results the authors obtained at the end of this first testing and setting up period, and therefore it assumes the form of a methodological protocol for carrying out the research itself.

Ecosystem productivity is associated with bacterial phylogenetic distance in surface marine waters.

Science.gov (United States)

Galand, Pierre E; Salter, Ian; Kalenitchenko, Dimitri

2015-12-01

Understanding the link between community diversity and ecosystem function is a fundamental aspect of ecology. Systematic losses in biodiversity are widely acknowledged but the impact this may exert on ecosystem functioning remains ambiguous. There is growing evidence of a positive relationship between species richness and ecosystem productivity for terrestrial macro-organisms, but similar links for marine micro-organisms, which help drive global climate, are unclear. Community manipulation experiments show both positive and negative relationships for microbes. These previous studies rely, however, on artificial communities and any links between the full diversity of active bacterial communities in the environment, their phylogenetic relatedness and ecosystem function remain hitherto unexplored. Here, we test the hypothesis that productivity is associated with diversity in the metabolically active fraction of microbial communities. We show in natural assemblages of active bacteria that communities containing more distantly related members were associated with higher bacterial production. The positive phylogenetic diversity-productivity relationship was independent of community diversity calculated as the Shannon index. From our long-term (7-year) survey of surface marine bacterial communities, we also found that similarly, productive communities had greater phylogenetic similarity to each other, further suggesting that the traits of active bacteria are an important predictor of ecosystem productivity. Our findings demonstrate that the evolutionary history of the active fraction of a microbial community is critical for understanding their role in ecosystem functioning. © 2015 John Wiley & Sons Ltd.

The potential of novel native plant materials for the restoration of novel ecosystems

Directory of Open Access Journals (Sweden)

T.A. Jones

2015-05-01

Full Text Available Abstract Extensive ecological change has been sustained by many dryland ecosystems throughout the world, resulting in conversion to so-called novel ecosystems. It is within such ecological contexts that native plant materials destined for ecological applications must be able to function. In the Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis [Beetle & A.M. Young] S.L. Welsh ecosystems of the Intermountain West, for example, novel ecosystem structure and functioning are pervasive. Invasive species, particularly annual grasses, fuel repeated wildfires that drive previously stable ecosystem states across thresholds to less desirable states that are highly recalcitrant to restoration efforts. Structural changes include reductions of native flora, damage to biological soil crusts, and alterations to soil microbiota. Functional changes include altered hydrologic and nutrient cycling, leading to permanent losses of soil organic matter and nitrogen that favor the invaders. We argue that there is an important place in restoration for plant materials that are novel and/or non-local that have been developed to be more effective in the novel ecosystems for which they are intended, thus qualifying them as “ecologically appropriate.” Such plant materials may be considered as an alternative to natural/local “genetically appropriate” plant materials, which are sometimes deemed best adapted due to vetting by historical evolutionary processes.

Linking ecosystem characteristics to final ecosystem services for public policy

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Wong, Christina P; Jiang, Bo; Kinzig, Ann P; Lee, Kai N; Ouyang, Zhiyun

2015-01-01

Governments worldwide are recognising ecosystem services as an approach to address sustainability challenges. Decision-makers need credible and legitimate measurements of ecosystem services to evaluate decisions for trade-offs to make wise choices. Managers lack these measurements because of a data gap linking ecosystem characteristics to final ecosystem services. The dominant method to address the data gap is benefit transfer using ecological data from one location to estimate ecosystem services at other locations with similar land cover. However, benefit transfer is only valid once the data gap is adequately resolved. Disciplinary frames separating ecology from economics and policy have resulted in confusion on concepts and methods preventing progress on the data gap. In this study, we present a 10-step approach to unify concepts, methods and data from the disparate disciplines to offer guidance on overcoming the data gap. We suggest: (1) estimate ecosystem characteristics using biophysical models, (2) identify final ecosystem services using endpoints and (3) connect them using ecological production functions to quantify biophysical trade-offs. The guidance is strategic for public policy because analysts need to be: (1) realistic when setting priorities, (2) attentive to timelines to acquire relevant data, given resources and (3) responsive to the needs of decision-makers. PMID:25394857

Forest Ecosystem Services and Eco-Compensation Mechanisms in China

Science.gov (United States)

Deng, Hongbing; Zheng, Peng; Liu, Tianxing; Liu, Xin

2011-12-01

Forests are a major terrestrial ecosystem providing multiple ecosystem services. However, the importance of forests is frequently underestimated from an economic perspective because of the externalities and public good properties of these services. Forest eco-compensation is a transfer mechanism that serves to internalize the externalities of forest ecosystem services by compensating individuals or companies for the losses or costs resulting from the provision of these services. China's current forest eco-compensation system is centered mainly on noncommercial forest. The primary measures associated with ecosystem services are (1) a charge on destructive activities, such as indiscriminate logging, and (2) compensation for individual or local activities and investments in forest conservation. The Compensation Fund System for Forest Ecological Benefits was first listed in the Forest Law of the People's Republic of China in 1998. In 2004, the Central Government Financial Compensation Fund, an important source for the Compensation Fund for Forest Ecological Benefits, was formally established. To improve the forest eco-compensation system, it is crucial to design and establish compensation criteria for noncommercial forests. These criteria should take both theoretical and practical concerns into account, and they should be based on the quantitative valuation of ecosystem services. Although some initial headway has been made on this task, the implementation of an effective forest eco-compensation system in China still has deficiencies and still faces problems. Implementing classification-based and dynamic management for key noncommercial forests and establishing an eco-compensation mechanism with multiple funding sources in the market economy are the key measures needed to conquer these problems and improve the forest eco-compensation system and China's forestry development in sequence.

Forest ecosystem services and eco-compensation mechanisms in China.

Science.gov (United States)

Deng, Hongbing; Zheng, Peng; Liu, Tianxing; Liu, Xin

2011-12-01

Forests are a major terrestrial ecosystem providing multiple ecosystem services. However, the importance of forests is frequently underestimated from an economic perspective because of the externalities and public good properties of these services. Forest eco-compensation is a transfer mechanism that serves to internalize the externalities of forest ecosystem services by compensating individuals or companies for the losses or costs resulting from the provision of these services. China's current forest eco-compensation system is centered mainly on noncommercial forest. The primary measures associated with ecosystem services are (1) a charge on destructive activities, such as indiscriminate logging, and (2) compensation for individual or local activities and investments in forest conservation. The Compensation Fund System for Forest Ecological Benefits was first listed in the Forest Law of the People's Republic of China in 1998. In 2004, the Central Government Financial Compensation Fund, an important source for the Compensation Fund for Forest Ecological Benefits, was formally established. To improve the forest eco-compensation system, it is crucial to design and establish compensation criteria for noncommercial forests. These criteria should take both theoretical and practical concerns into account, and they should be based on the quantitative valuation of ecosystem services. Although some initial headway has been made on this task, the implementation of an effective forest eco-compensation system in China still has deficiencies and still faces problems. Implementing classification-based and dynamic management for key noncommercial forests and establishing an eco-compensation mechanism with multiple funding sources in the market economy are the key measures needed to conquer these problems and improve the forest eco-compensation system and China's forestry development in sequence.

Vascular plants promote ancient peatland carbon loss with climate warming.

Science.gov (United States)

Walker, Tom N; Garnett, Mark H; Ward, Susan E; Oakley, Simon; Bardgett, Richard D; Ostle, Nicholas J

2016-05-01

Northern peatlands have accumulated one third of the Earth's soil carbon stock since the last Ice Age. Rapid warming across northern biomes threatens to accelerate rates of peatland ecosystem respiration. Despite compensatory increases in net primary production, greater ecosystem respiration could signal the release of ancient, century- to millennia-old carbon from the peatland organic matter stock. Warming has already been shown to promote ancient peatland carbon release, but, despite the key role of vegetation in carbon dynamics, little is known about how plants influence the source of peatland ecosystem respiration. Here, we address this issue using in situ (14)C measurements of ecosystem respiration on an established peatland warming and vegetation manipulation experiment. Results show that warming of approximately 1 °C promotes respiration of ancient peatland carbon (up to 2100 years old) when dwarf-shrubs or graminoids are present, an effect not observed when only bryophytes are present. We demonstrate that warming likely promotes ancient peatland carbon release via its control over organic inputs from vascular plants. Our findings suggest that dwarf-shrubs and graminoids prime microbial decomposition of previously 'locked-up' organic matter from potentially deep in the peat profile, facilitating liberation of ancient carbon as CO2. Furthermore, such plant-induced peat respiration could contribute up to 40% of ecosystem CO2 emissions. If consistent across other subarctic and arctic ecosystems, this represents a considerable fraction of ecosystem respiration that is currently not acknowledged by global carbon cycle models. Ultimately, greater contribution of ancient carbon to ecosystem respiration may signal the loss of a previously stable peatland carbon pool, creating potential feedbacks to future climate change. © 2016 John Wiley & Sons Ltd.

Approaches to modelling hydrology and ecosystem interactions

Science.gov (United States)

Silberstein, Richard P.

2014-05-01

As the pressures of industry, agriculture and mining on groundwater resources increase there is a burgeoning un-met need to be able to capture these multiple, direct and indirect stresses in a formal framework that will enable better assessment of impact scenarios. While there are many catchment hydrological models and there are some models that represent ecological states and change (e.g. FLAMES, Liedloff and Cook, 2007), these have not been linked in any deterministic or substantive way. Without such coupled eco-hydrological models quantitative assessments of impacts from water use intensification on water dependent ecosystems under changing climate are difficult, if not impossible. The concept would include facility for direct and indirect water related stresses that may develop around mining and well operations, climate stresses, such as rainfall and temperature, biological stresses, such as diseases and invasive species, and competition such as encroachment from other competing land uses. Indirect water impacts could be, for example, a change in groundwater conditions has an impact on stream flow regime, and hence aquatic ecosystems. This paper reviews previous work examining models combining ecology and hydrology with a view to developing a conceptual framework linking a biophysically defensable model that combines ecosystem function with hydrology. The objective is to develop a model capable of representing the cumulative impact of multiple stresses on water resources and associated ecosystem function.

Establishing IUCN Red List Criteria for Threatened Ecosystems

Science.gov (United States)

Rodríguez, Jon Paul; Rodríguez-Clark, Kathryn M; Baillie, Jonathan E M; Ash, Neville; Benson, John; Boucher, Timothy; Brown, Claire; Burgess, Neil D; Collen, Ben; Jennings, Michael; Keith, David A; Nicholson, Emily; Revenga, Carmen; Reyers, Belinda; Rouget, Mathieu; Smith, Tammy; Spalding, Mark; Taber, Andrew; Walpole, Matt; Zager, Irene; Zamin, Tara

2011-01-01

Abstract The potential for conservation of individual species has been greatly advanced by the International Union for Conservation of Nature's (IUCN) development of objective, repeatable, and transparent criteria for assessing extinction risk that explicitly separate risk assessment from priority setting. At the IV World Conservation Congress in 2008, the process began to develop and implement comparable global standards for ecosystems. A working group established by the IUCN has begun formulating a system of quantitative categories and criteria, analogous to those used for species, for assigning levels of threat to ecosystems at local, regional, and global levels. A final system will require definitions of ecosystems; quantification of ecosystem status; identification of the stages of degradation and loss of ecosystems; proxy measures of risk (criteria); classification thresholds for these criteria; and standardized methods for performing assessments. The system will need to reflect the degree and rate of change in an ecosystem's extent, composition, structure, and function, and have its conceptual roots in ecological theory and empirical research. On the basis of these requirements and the hypothesis that ecosystem risk is a function of the risk of its component species, we propose a set of four criteria: recent declines in distribution or ecological function, historical total loss in distribution or ecological function, small distribution combined with decline, or very small distribution. Most work has focused on terrestrial ecosystems, but comparable thresholds and criteria for freshwater and marine ecosystems are also needed. These are the first steps in an international consultation process that will lead to a unified proposal to be presented at the next World Conservation Congress in 2012. Establecimiento de Criterios para la Lista Roja de UICN de Ecosistemas Amenazados Resumen El potencial para la conservación de muchas especies ha avanzado enormemente

Towards ecosystem accounting

NARCIS (Netherlands)

Duku, C.; Rathjens, H.; Zwart, S.J.; Hein, L.

2015-01-01

Ecosystem accounting is an emerging field that aims to provide a consistent approach to analysing environment-economy interactions. One of the specific features of ecosystem accounting is the distinction between the capacity and the flow of ecosystem services. Ecohydrological modelling to support

The Ecosystem of Startups as a Component of the Innovation Ecosystem

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Sytnik Natalia I.

2017-08-01

Full Text Available The article analyzes the current theoretical perceptions of the ecosystem of startups and presents the author’s own vision of this entity. It has been proposed to consider the ecosystem of startups as a subsystem of the innovation ecosystem, which aims at creating innovative products and services by startup companies. The ecosystem of startups is an open dynamic system in which the backbone subject is a startup company at various stages of the life cycle. The sustenance subjects in an ecosystem are the organizations, associations and individuals that cause impacts, to varying degrees, on the establishing or development of startups. The activities of the subjects are carried out in the following directions: public regulation, financing, training, information, and infrastructure support for startups. The ecosystem consists of a number of economic, material-and-technical, market, and socio-cultural factors that directly or indirectly influence the actions of the subjects. The vital activity of the ecosystem of startups is maintained by the active interaction of the subjects, connected by a network of internal links with the environment and between themselves.

A Modified Gash Model for Estimating Rainfall Interception Loss of Forest Using Remote Sensing Observations at Regional Scale

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Yaokui Cui

2014-04-01

Full Text Available Rainfall interception loss of forest is an important component of water balance in a forested ecosystem. The Gash analytical model has been widely used to estimate the forest interception loss at field scale. In this study, we proposed a simple model to estimate rainfall interception loss of heterogeneous forest at regional scale with several reasonable assumptions using remote sensing observations. The model is a modified Gash analytical model using easily measured parameters of forest structure from satellite data and extends the original Gash model from point-scale to the regional scale. Preliminary results, using remote sensing data from Moderate Resolution Imaging Spectroradiometer (MODIS products, field measured rainfall data, and meteorological data of the Automatic Weather Station (AWS over a picea crassifolia forest in the upper reaches of the Heihe River Basin in northwestern China, showed reasonable accuracy in estimating rainfall interception loss at both the Dayekou experimental site (R2 = 0.91, RMSE = 0.34 mm∙d −1 and the Pailugou experimental site (R2 = 0.82, RMSE = 0.6 mm∙d −1, compared with ground measurements based on per unit area of forest. The interception loss map of the study area was shown to be strongly heterogeneous. The modified model has robust physics and is insensitive to the input parameters, according to the sensitivity analysis using numerical simulations. The modified model appears to be stable and easy to be applied for operational estimation of interception loss over large areas.

The “genetic erosion” of the soil ecosystem

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Giuseppe Lo Papa

2013-06-01

Full Text Available This paper takes into consideration the influence of human activities on the loss of pedodiversity in a Mediterranean area due to large scale farming. In particular it examines the quantitative and qualitative soil changes in a period of 53 years (from 1955 to 2008 evaluating the loss of soil diversity at soil subgroups level of the USDA Soil Taxonomy system. The following indices were used: richness; Shannon’s diversity index; Simpson diversity index; Shannon’s evenness index; Simpson’s evenness index. In this case study, considering what we observed in time, the human intervention in soil transformation could increase the diversity in the landscape in an initial phase, but forwarding by large scale farming the result is a huge loss of pedodiversity in time, as diversity indices remarkably have shown. This analysis enabled identification of disappeared soil types, with their unique history of formation. In our opinion this strongly reflects a sort of “genetic erosion” of the soil types, resulting in a substantial weakening of the whole pedo-ecosystem.

[Quantitative analysis of blood loss in liposuction].

Science.gov (United States)

Schor, N; Zatz, R M; Mendonça, A R; Takatu, P M; Patto, G S

1989-01-01

This study was performed in 15 female patients submitted to suction lipectomy as an isolated procedure, to establish blood loss in the procedure. A wide variation of blood-to-fat ratios was observed (17 to 59%) with a mean blood loss in lipoaspirates of 34 +/- 3%. Internal blood losses occurring in the first 72 post-operative hours were as important as or more important than external losses, and responsible for a mean 7% fall in the level of hemoglobin. Internal blood losses occurred between 72 hours and the 7th to the 10th post-operative days and were responsible for a mean 3% fall in the level of hemoglobin. Blood losses occurring in this study were demonstrated to be greater than usually assumed. Some prophylactic measures are recommended to provide for a safer treatment of these patients: an iron supplementation during the pre-operative period; careful clinical and laboratorial screening for bleeding disorders and for the intake of drugs that can interfere with coagulation; use of smaller-diameter cannulas for aspiration, auto-transfusion when aspirating in excess of 1,000 ml, and limiting the aspiration to 1,500 ml.

Tundra biome research in Alaska: the structure and function of cold-dominated ecosystems

Energy Technology Data Exchange (ETDEWEB)

Brown, J.; West, G.C.

1970-11-01

The objective of the Tundra Biome Program is to acquire a basic understanding of tundra, both alpine and arctic, and taiga. Collectively these are referred to as the cold-dominated ecosystems. The program's broad objectives are threefold: To develop a predictive understanding of how the wet arctic tundra ecosystem operates, particularly as exemplified in the Barrow, Alaska, area; to obtain the necessary data base from the variety of cold-dominated ecosystem types represented in the United States, so that their behavior can be modeled and simulated, and the results compared with similar studies underway in other circumpolar countries; to bring basic environmental knowledge to bear on problems of degradation, maintenance, and restoration of the temperature-sensitive and cold-dominated tundra/taiga ecosystems. (GRA)

Dynamics of organic carbon losses by water erosion after biocrust removal

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Cantón Yolanda

2014-12-01

Full Text Available In arid and semiarid ecosystems, plant interspaces are frequently covered by communities of cyanobacteria, algae, lichens and mosses, known as biocrusts. These crusts often act as runoff sources and are involved in soil stabilization and fertility, as they prevent erosion by water and wind, fix atmospheric C and N and contribute large amounts of C to soil. Their contribution to the C balance as photosynthetically active surfaces in arid and semiarid regions is receiving growing attention. However, very few studies have explicitly evaluated their contribution to organic carbon (OC lost from runoff and erosion, which is necessary to ascertain the role of biocrusts in the ecosystem C balance. Furthermore, biocrusts are not resilient to physical disturbances, which generally cause the loss of the biocrust and thus, an increase in runoff and erosion, dust emissions, and sediment and nutrient losses. The aim of this study was to find out the influence of biocrusts and their removal on dissolved and sediment organic carbon losses. One-hour extreme rainfall simulations (50 mm h-1 were performed on small plots set up on physical soil crusts and three types of biocrusts, representing a development gradient, and also on plots where these crusts were removed from. Runoff and erosion rates, dissolved organic carbon (DOC and organic carbon bonded to sediments (SdOC were measured during the simulated rain. Our results showed different SdOC and DOC for the different biocrusts and also that the presence of biocrusts substantially decreased total organic carbon (TOC (average 1.80±1.86 g m-2 compared to physical soil crusts (7.83±3.27 g m-2. Within biocrusts, TOC losses decreased as biocrusts developed, and erosion rates were lower. Thus, erosion drove TOC losses while no significant direct relationships were found between TOC losses and runoff. In both physical crusts and biocrusts, DOC and SdOC concentrations were higher during the first minutes after runoff

Introduced and invasive species in novel rangeland ecosystems: friends or foes?

Science.gov (United States)

Belnap, Jayne; Ludwig, John A.; Wilcox, Bradford P.; Betancourt, Julio L.; Dean, W. Richard J.; Hoffmann, Benjamin D.; Milton, Sue J.

2012-01-01

Globally, new combinations of introduced and native plant and animal species have changed rangelands into novel ecosystems. Whereas many rangeland stakeholders (people who use or have an interest in rangelands) view intentional species introductions to improve forage and control erosion as beneficial, others focus on unintended costs, such as increased fire risk, loss of rangeland biodiversity, and threats to conservation efforts, specifically in nature reserves and parks. These conflicting views challenge all rangeland stakeholders, especially those making decisions on how best to manage novel ecosystems. To formulate a conceptual framework for decision making, we examined a wide range of novel ecosystems, created by intentional and unintentional introductions of nonnative species and land-use–facilitated spread of native ones. This framework simply divides decision making into two types: 1) straightforward–certain, and 2) complex–uncertain. We argue that management decisions to retain novel ecosystems are certain when goods and services provided by the system far outweigh the costs of restoration, for example in the case of intensively managed Cenchrus pastures. Decisions to return novel ecosystems to natural systems are also certain when the value of the system is low and restoration is easy and inexpensive as in the case of biocontrol of Opuntia infestations. In contrast, decisions whether to retain or restore novel ecosystems become complex and uncertain in cases where benefits are low and costs of control are high as, for example, in the case of stopping the expansion of Prosopis and Juniperus into semiarid rangelands. Decisions to retain or restore novel ecosystems are also complex and uncertain when, for example, nonnative Eucalyptus trees expand along natural streams, negatively affecting biodiversity, but also providing timber and honey. When decision making is complex and uncertain, we suggest that rangeland managers utilize cost–benefit analyses

Incorporating Ecosystem Goods and Services in Environmental Planning - Definitions, Classification and Operational Approaches

Science.gov (United States)

2013-07-01

the characteristics of the surrounding landscape , including proximity to and use by people are considered as key determinants in the levels and values...a certain level of management may be necessary in some environments. Within the definition of ecosystem goods and services, there are two major...regulation Erosion regulation Disease regulation Pest regulation Pollination Cultural Cultural diversity Spiritual and religious values Recreation

Models for predicting fuel consumption in sagebrush-dominated ecosystems

Science.gov (United States)

Clinton S. Wright

2013-01-01

Fuel consumption predictions are necessary to accurately estimate or model fire effects, including pollutant emissions during wildland fires. Fuel and environmental measurements on a series of operational prescribed fires were used to develop empirical models for predicting fuel consumption in big sagebrush (Artemisia tridentate Nutt.) ecosystems....

Structurally complex habitats provided by Acropora palmata influence ecosystem processes on a reef in the Florida Keys National Marine Sanctuary

Science.gov (United States)

Lemoine, N. P.; Valentine, J. F.

2012-09-01

The disappearance of Acropora palmata from reefs in the Florida Keys National Marine Sanctuary (FKNMS) represents a significant loss in the amount of structurally complex habitat available for reef-associated species. The consequences of such a widespread loss of complex structure on ecosystem processes are still unclear. We sought to determine whether the disappearance of complex structure has adversely affected grazing and invertebrate predation rates on a shallow reef in the FKNMS. Surprisingly, we found grazing rates and invertebrate predation rates were lower in the structurally complex A. palmata branches than on the topographically simple degraded reefs. We attribute these results to high densities of aggressively territorial damselfish, Stegastes planifrons, living within A. palmata. Our study suggests the presence of agonistic damselfish can cause the realized spatial patterns of ecosystem processes to deviate from the expected patterns. Reef ecologists must therefore carefully consider the assemblage of associate fish communities when assessing how the mortality of A. palmata has affected coral reef ecosystem processes.

Bibliography of environmental research: Ecosystems Department, 1952--1975

International Nuclear Information System (INIS)

Helbling, J.L.

1975-12-01

This 3rd biennial edition of the Cumulative Bibliography of Environmental Research was prepared as a single source of information on the publication history of the Ecosystems Department, from its genesis in the Biology Operation of General Electric, to its present status as an independent department of the Pacific Northwest Laboratories of Battelle Memorial Institute

Global Trends in Exposure to Light Pollution in Natural Terrestrial Ecosystems

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Jonathan Bennie

2015-03-01

Full Text Available The rapid growth in electric light usage across the globe has led to increasing presence of artificial light in natural and semi-natural ecosystems at night. This occurs both due to direct illumination and skyglow - scattered light in the atmosphere. There is increasing concern about the effects of artificial light on biological processes, biodiversity and the functioning of ecosystems. We combine intercalibrated Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS images of stable night-time lights for the period 1992 to 2012 with a remotely sensed landcover product (GLC2000 to assess recent changes in exposure to artificial light at night in 43 global ecosystem types. We find that Mediterranean-climate ecosystems have experienced the greatest increases in exposure, followed by temperate ecosystems. Boreal, Arctic and montane systems experienced the lowest increases. In tropical and subtropical regions, the greatest increases are in mangroves and subtropical needleleaf and mixed forests, and in arid regions increases are mainly in forest and agricultural areas. The global ecosystems experiencing the greatest increase in exposure to artificial light are already localized and fragmented, and often of particular conservation importance due to high levels of diversity, endemism and rarity. Night time remote sensing can play a key role in identifying the extent to which natural ecosystems are exposed to light pollution.

The role of arbuscular mycorrhizas in reducing soil nutrient loss.

Science.gov (United States)

Cavagnaro, Timothy R; Bender, S Franz; Asghari, Hamid R; Heijden, Marcel G A van der

2015-05-01

Substantial amounts of nutrients are lost from soils via leaching and as gaseous emissions. These losses can be environmentally damaging and expensive in terms of lost agricultural production. Plants have evolved many traits to optimize nutrient acquisition, including the formation of arbuscular mycorrhizas (AM), associations of plant roots with fungi that acquire soil nutrients. There is emerging evidence that AM have the ability to reduce nutrient loss from soils by enlarging the nutrient interception zone and preventing nutrient loss after rain-induced leaching events. Until recently, this important ecosystem service of AM had been largely overlooked. Here we review the role of AM in reducing nutrient loss and conclude that this role cannot be ignored if we are to increase global food production in an environmentally sustainable manner. Copyright © 2015 Elsevier Ltd. All rights reserved.

Linking ecosystem characteristics to final ecosystem services for public policy.

Science.gov (United States)

Wong, Christina P; Jiang, Bo; Kinzig, Ann P; Lee, Kai N; Ouyang, Zhiyun

2015-01-01

Governments worldwide are recognising ecosystem services as an approach to address sustainability challenges. Decision-makers need credible and legitimate measurements of ecosystem services to evaluate decisions for trade-offs to make wise choices. Managers lack these measurements because of a data gap linking ecosystem characteristics to final ecosystem services. The dominant method to address the data gap is benefit transfer using ecological data from one location to estimate ecosystem services at other locations with similar land cover. However, benefit transfer is only valid once the data gap is adequately resolved. Disciplinary frames separating ecology from economics and policy have resulted in confusion on concepts and methods preventing progress on the data gap. In this study, we present a 10-step approach to unify concepts, methods and data from the disparate disciplines to offer guidance on overcoming the data gap. We suggest: (1) estimate ecosystem characteristics using biophysical models, (2) identify final ecosystem services using endpoints and (3) connect them using ecological production functions to quantify biophysical trade-offs. The guidance is strategic for public policy because analysts need to be: (1) realistic when setting priorities, (2) attentive to timelines to acquire relevant data, given resources and (3) responsive to the needs of decision-makers. © 2014 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.

Major impacts of climate change on deep-sea benthic ecosystems

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Andrew K. Sweetman

2017-02-01

Full Text Available The deep sea encompasses the largest ecosystems on Earth. Although poorly known, deep seafloor ecosystems provide services that are vitally important to the entire ocean and biosphere. Rising atmospheric greenhouse gases are bringing about significant changes in the environmental properties of the ocean realm in terms of water column oxygenation, temperature, pH and food supply, with concomitant impacts on deep-sea ecosystems. Projections suggest that abyssal (3000–6000 m ocean temperatures could increase by 1°C over the next 84 years, while abyssal seafloor habitats under areas of deep-water formation may experience reductions in water column oxygen concentrations by as much as 0.03 mL L–1 by 2100. Bathyal depths (200–3000 m worldwide will undergo the most significant reductions in pH in all oceans by the year 2100 (0.29 to 0.37 pH units. O2 concentrations will also decline in the bathyal NE Pacific and Southern Oceans, with losses up to 3.7% or more, especially at intermediate depths. Another important environmental parameter, the flux of particulate organic matter to the seafloor, is likely to decline significantly in most oceans, most notably in the abyssal and bathyal Indian Ocean where it is predicted to decrease by 40–55% by the end of the century. Unfortunately, how these major changes will affect deep-seafloor ecosystems is, in some cases, very poorly understood. In this paper, we provide a detailed overview of the impacts of these changing environmental parameters on deep-seafloor ecosystems that will most likely be seen by 2100 in continental margin, abyssal and polar settings. We also consider how these changes may combine with other anthropogenic stressors (e.g., fishing, mineral mining, oil and gas extraction to further impact deep-seafloor ecosystems and discuss the possible societal implications.

An integrated ecosystem model for coral reef management where oceanography, ecology and socio-economics meet

NARCIS (Netherlands)

Weijerman, Mariska

2015-01-01

Widespread coral reef decline, including decline in reef fish populations upon which many coastal human populations depend, have led to phase-shifts from the coral-dominated systems, found desirable by humans, to algal-dominated systems that provide less ecosystem services, and the loss of

7 CFR 1493.130 - Recovery of losses.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Recovery of losses. 1493.130 Section 1493.130...) Operations § 1493.130 Recovery of losses. (a) Notification. Upon payment of loss to the exporter or the... by CCC's Payment Guarantee: $4,668.55 Computation of Pro Rata Sharing in Recovery of Losses In...

Assessing changes in the value of ecosystem services in response to land-use/land-cover dynamics in Nigeria.

Science.gov (United States)

Arowolo, Aisha Olushola; Deng, Xiangzheng; Olatunji, Olusanya Abiodun; Obayelu, Abiodun Elijah

2018-09-15

Increasing human activities worldwide have significantly altered the natural ecosystems and consequently, the services they provide. This is no exception in Nigeria, where land-use/land-cover has undergone a series of dramatic changes over the years mainly due to the ever-growing large population. However, estimating the impact of such changes on a wide range of ecosystem services is seldom attempted. Thus, on the basis of GlobeLand30 land-cover maps for 2000 and 2010 and using the value transfer methodology, we evaluated changes in the value of ecosystem services in response to land-use/land-cover dynamics in Nigeria. The results showed that over the 10-year period, cultivated land sprawl over the forests and savannahs was predominant, and occurred mainly in the northern region of the country. During this period, we calculated an increase in the total ecosystem services value (ESV) in Nigeria from 665.93 billion (2007 US$) in 2000 to 667.44 billion (2007 US$) in 2010, 97.38% of which was contributed by cultivated land. The value of provisioning services increased while regulation, support, recreation and culture services decreased, amongst which, water regulation (-11.01%), gas regulation (-7.13%), cultural (-4.84%) and climate regulation (-4.3%) ecosystem functions are estimated as the most impacted. The increase in the total ESV in Nigeria associated with the huge increase in ecosystem services due to cultivated land expansion may make land-use changes (i.e. the ever-increasing agricultural expansion in Nigeria) appear economically profitable. However, continuous loss of services such as climate and water regulation that are largely provided by the natural ecosystems can result in huge economic losses that may exceed the apparent gains from cultivated land development. Therefore, we advocate that the conservation of the natural ecosystem should be a priority in future land-use management in Nigeria, a country highly vulnerable to climate change and incessantly

Modeling operator actions during a small break loss-of-coolant accident in a Babcock and Wilcox nuclear power plant

International Nuclear Information System (INIS)

Ghan, L.S.; Ortiz, M.G.

1991-01-01

A small break loss-of-accident (SBLOCA) in a typical Babcock and Wilcox (B ampersand W) nuclear power plant was modeled using RELAP5/MOD3. This work was performed as part of the United States Regulatory Commission's (USNRC) Code, Scaling, Applicability and Uncertainty (CSAU) study. The break was initiated by severing one high pressure injection (HPI) line at the cold leg. Thus, the small break was further aggravated by reduced HPI flow. Comparisons between scoping runs with minimal operator action, and full operator action, clearly showed that the operator plays a key role in recovering the plant. Operator actions were modeled based on the emergency operating procedures (EOPs) and the Technical Bases Document for the EOPs. The sequence of operator actions modeled here is only one of several possibilities. Different sequences of operator actions are possible for a given accident because of the subjective decisions the operator must make when determining the status of the plant, hence, which branch of the EOP to follow. To assess the credibility of the modeled operator actions, these actions and results of the simulated accident scenario were presented to operator examiners who are familiar with B ampersand W nuclear power plants. They agreed that, in general, the modeled operator actions conform to the requirements set forth in the EOPs and are therefore plausible. This paper presents the method for modeling the operator actions and discusses the simulated accident scenario from the viewpoint of operator actions