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181.
Numerous studies have examined relationships between primary production and biodiversity at higher trophic levels. However, altered production in plant communities is often tightly linked with concomitant shifts in diversity and composition, and most studies have not disentangled the direct effects of production on consumers. Furthermore, when studies do examine the effects of plant production on animals in terrestrial systems, they are primarily confined to a subset of taxonomic or functional groups instead of investigating the responses of the entire community. Using natural monocultures of the salt marsh cordgrass Spartina alterniflora, we were able to examine the impacts of increased plant production, independent of changes in plant composition and/or diversity, on the trophic structure, composition, and diversity of the entire arthropod community. If arthropod species richness increased with greater plant production, we predicted that it would be driven by: (1) an increase in the number of rare species, and/or (2) an increase in arthropod abundance. Our results largely supported our predictions: species richness of herbivores, detritivores, predators, and parasitoids increased monotonically with increasing levels of plant production, and the diversity of rare species also increased with plant production. However, rare species that accounted for this difference were predators, parasitoids, and detritivores, not herbivores. Herbivore species richness could be simply explained by the relationship between abundance and diversity. Using nonmetric multidimensional scaling (NMDS) and analysis of similarity (ANOSIM), we also found significant changes in arthropod species composition with increasing levels of production. Our findings have important implications in the intertidal salt marsh, where human activities have increased nitrogen runoff into the marsh, and demonstrate that such nitrogen inputs cascade to affect community structure, diversity, and abundance in higher trophic levels. 相似文献
182.
Philippa Douglas Daniela Fecht Deborah Jarvis 《Frontiers of Environmental Science & Engineering》2021,15(3):40
183.
184.
Deborah Elcock 《Journal of the American Water Resources Association》2010,46(3):447-460
Elcock, Deborah, 2010. Future U.S. Water Consumption: The Role of Energy Production. Journal of the American Water Resources Association (JAWRA) 46(3):447-460. DOI: 10.1111/j.1752-1688.2009.00413.x Abstract: This study investigates how meeting domestic energy production targets for both fossil and renewable fuels may affect future water demand. It combines projections of energy production developed by the U.S. Department of Energy with estimates of water consumption on a per-unit basis (water-consumption coefficients) for coal, oil, gas, and biofuels production, to estimate and compare the domestic freshwater consumed. Although total domestic freshwater consumption is expected to increase by nearly 7% between 2005 and 2030, water consumed for energy production is expected to increase by nearly 70%, and water consumed for biofuels (biodiesel and ethanol) production is expected to increase by almost 250%. By 2030, water consumed in the production of biofuels is projected to account for nearly half of the total amount of water consumed in the production of all energy fuels. Most of this is for irrigation, and the West North Central Region is projected to consume most of this water in 2030. These findings identify an important potential future conflict between renewable energy production and water availability that warrants further investigation and action to ensure that future domestic energy demand can be met in an economically efficient and environmentally sustainable manner. 相似文献
185.
Jacqueline Geoghegan Deborah Lawrence Laura C. Schneider Katherine Tully 《Regional Environmental Change》2010,10(3):247-260
To assess the impact of land-use change on carbon stocks, we apply a new methodology, linking ecological and economic modeling,
to southern Yucatan, Mexico. A spatial econometric multinomial logit model of ten land-cover classes is estimated (four primary
forest categories, three secondary growth categories, an invasive species, and two agricultural land-cover categories), using
satellite data on land cover, linked with census socioeconomic data and other biophysical spatial data from 2000. The analysis
is novel in that it is the first attempt to link detailed satellite data on land use, with on-the-ground estimates of carbon
stocks in a spatial econometric model of land use. The estimated multinomial logit model is then used with two scenarios of
future economic growth (“low growth” and “high growth” changes in population, agricultural land use, market access, and education
levels) in the region to predict land-cover changes resulting from the economic growth. The per hectare carbon (C) stocks
in each land-cover class are derived from previously published estimates of biomass from field sampling across the study region.
We consider aboveground-only, aboveground plus soil, transient and non-transient pools of carbon. These estimates are scaled
up to the total area in each class according to the predictions of the model baseline and the two development scenarios. Subsequently,
the changes in carbon stocks resulting from the predicted land-cover changes are calculated. Under the low growth scenario,
carbon stocks declined by 5%; under the high growth scenario, losses were 12%. Including soil C, the proportional losses were
lower, but the absolute amount lost was more than double (to 6 Tg C under the low and almost 15 Tg C under the high-growth
scenario). This methodology could be further developed for applications in global change policy, such as payments for environmental
services (PES) or reduction in emissions from deforestation and degradation (REDD). 相似文献
186.
Behavioural and biochemical responses of two marine invertebrates Scrobicularia plana and Hediste diversicolor to copper oxide nanoparticles 总被引:1,自引:0,他引:1
Buffet PE Tankoua OF Pan JF Berhanu D Herrenknecht C Poirier L Amiard-Triquet C Amiard JC Bérard JB Risso C Guibbolini M Roméo M Reip P Valsami-Jones E Mouneyrac C 《Chemosphere》2011,84(1):166-174
Engineered nano-sized Cu oxide particles are extensively used in diverse applications. Because aquatic environments are the ultimate “sink” for all contaminants, it is expected that nanoparticles (NP) will follow the same fate. In this study, two marine invertebrates Scrobicularia plana and Hediste diversicolor were chosen as ecotoxicological models. The aim was to evaluate behavioural (burrowing kinetics, feeding rate) and biochemical (biomarkers) responses of S. plana and H. diversicolor exposed in the laboratory to Cu (10 μg L−1) added in natural seawater either in the form of engineered nanoparticles (NPs) of CuO or as dissolved Cu in 2% HNO3. Exposure was characterized by considering (i) the physico-chemical fate of NP (ii) the fraction of labile Cu in experimental media and (iii) Cu bioaccumulation. Results showed high aggregation of CuO NPs in seawater and no additional bioavailable Cu concentrations. Behavioural impairments were observed in S. plana exposed to CuO NPs or soluble Cu whereas in H. diversicolor, only the exposure to soluble Cu led to a burrowing decrease. No obvious neurotoxicity effects were revealed since in both species, no changes in cholinesterasic activity occurred in response to both forms of Cu exposure. Biomarkers of oxidative-stress catalase and glutathione-S-transferase were enhanced in both species whereas superoxide dismutase was increased only in S. plana exposed to CuO NPs. Metallothionein-like protein was increased in bivalves exposed to both forms of Cu. Since, no detectable release of soluble Cu from CuO NPs occurred during the time of experiment, ecotoxicity effects seem to be related to CuO NPs themselves. 相似文献
187.
Lin DS Greenwood PF George S Somerfield PJ Tibbett M 《Environmental science and pollution research international》2011,18(7):1070-1078
Background, aim and scope
Soil organic matter (SOM) is known to increase with time as landscapes recover after a major disturbance; however, little is known about the evolution of the chemistry of SOM in reconstructed ecosystems. In this study, we assessed the development of SOM chemistry in a chronosequence (space for time substitution) of restored Jarrah forest sites in Western Australia. 相似文献188.
Beck DA Johnson GR Spolek GA 《Environmental pollution (Barking, Essex : 1987)》2011,159(8-9):2111-2118
Numbers of greenroofs in urban areas continue to grow internationally; so designing greenroof soil to reduce the amount of nutrients in the stormwater runoff from these roofs is becoming essential. This study evaluated changes in extensive greenroof water discharge quality and quantity after adding biochar, a soil amendment promoted for its ability to retain nutrients in soils and increase soil fertility. Prototype greenroof trays with and without biochar were planted with sedum or ryegrass, with barren soil trays used as controls. The greenroof trays were subjected to two sequential 7.4cm/h rainfall events using a rain simulator. Runoff from the rain events was collected and evaluated. Trays containing 7% biochar showed increased water retention and significant decreases in discharge of total nitrogen, total phosphorus, nitrate, phosphate, and organic carbon. The addition of biochar to greenroof soil improves both runoff water quality and retention. 相似文献
189.
Multifoci effects of injustice on counterproductive work behaviors and the moderating roles of symbolization and victim sensitivity 下载免费PDF全文
James J. Lavelle Christopher M. Harris Deborah E. Rupp David N. Herda Randall F. Young M. Blake Hargrove Meghan Ann Thornton‐Lugo Gary C. McMahan 《组织行为杂志》2018,39(8):1022-1039
Past research suggests that employees, in response to workplace experiences, selectively engage in targeted counterproductive work behaviors (CWBs). Taking a retributive justice and target similarity perspective, we predict that employee perceptions of unfairness from the organization uniquely predict CWB specifically targeted at the organization whereas employee perceptions of supervisory unfairness uniquely predict CWB specifically targeted at the supervisor. We further hypothesized that moral identity‐symbolization would strengthen these target‐similar relationships. Finally, drawing from the sensitivity to mean intentions model, we hypothesized that victim sensitivity would not only strengthen these target‐similar relationships but also lead to cross‐foci effects of multifoci fairness perceptions on targets of CWB. Results from 3 field studies of full‐time employees provided support for most of our hypothesized relationships. 相似文献
190.
Crab samples, both male and female specie, were purchased from fishermen at the Ojo Rivers, Lagos, Nigeria. The samples separated
into abdomen, muscle tissue, and thorax were oven dried at 80°C for 3 days. The dried samples were then pulverized in a clean
acid-washed mortar and pestle. Approximately 1.00 g each of the pulverized samples was weighed and Zn, Cr, Pb, and Cd were
determined in the solution of the aqua regia digested samples by means of AAS (Buck Scientific 210 GVP model). The results
obtained showed Zn metal to be consistently higher in all the female parts compared to the male with values of 12.92 ± 3.65 μg/g
to 16.03 ± 1.08 μg/g and 9.33 ± 1.77 μg/g to 15.75 ± 1.02 μg/g, respectively. Mean values of 0.39 ± 0.09 μg/g and 0.22 ± 0.02 μg/g
cadmium were found in the abdomen and tissue of the male crab as against 0.35 ± 0.07 μg/g and 0.17 ± 0.07 μg/g in the female
crab. The tissues of both species have comparable value of chromium. Lead was below the detection limit of 0.05 μg/g in the
tissues of male crab but the female tissue contained 0.83 ± 0.13 μg/g and in other parts identified, lead was consistently
higher than the 2.00 μg/g permissible level of WHO in foods. A simple pair t-test did not demonstrate any significant difference in the distribution of metals between the male and female crabs. The
coefficient of variation (CV) calculated for each metal with respect to the studied parts showed Pb to be widely distributed
(56.23–89.54%) while Cr did not vary widely (4.17–8.20%). 相似文献