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421.
422.
Cecilia Luttrell Erin Sills Riza Aryani Andini Desita Ekaputri Maria Febe Evinke 《Mitigation and Adaptation Strategies for Global Change》2018,23(2):291-310
Reducing Emissions from Deforestation and Degradation (REDD+) in developing countries is based on the premise that conserving tropical forests is a cost-effective way to reduce carbon emissions and therefore can be fully funded by international actors with obligations or interests in reducing emissions. However, concerns have repeatedly been raised about whether stakeholders in REDD+ host countries will actually end up bearing the costs of REDD+. Most prior analyses of the costs of REDD+ have focused on the opportunity costs of foregone alternative uses of forest land. We draw on a pan-tropical study of 22 subnational REDD+ initiatives in five countries to explore patterns in implementation costs, including which types of organizations are involved and which are sharing the costs of implementing REDD+. We find that many organizations involved in the implementation of REDD+, particularly at the subnational level and in the public sector, are bearing implementation costs not covered by the budgets of the REDD+ initiatives. To sustain this level of cost-sharing, REDD+ must be designed to deliver local as well as global forest benefits. 相似文献
423.
Morrice JA Danz NP Regal RR Kelly JR Niemi GJ Reavie ED Hollenhorst T Axler RP Trebitz AS Cotter AM Peterson GS 《Environmental management》2008,41(3):347-357
A better understanding of relationships between human activities and water chemistry is needed to identify and manage sources
of anthropogenic stress in Great Lakes coastal wetlands. The objective of the study described in this article was to characterize
relationships between water chemistry and multiple classes of human activity (agriculture, population and development, point
source pollution, and atmospheric deposition). We also evaluated the influence of geomorphology and biogeographic factors
on stressor-water quality relationships. We collected water chemistry data from 98 coastal wetlands distributed along the
United States shoreline of the Laurentian Great Lakes and GIS-based stressor data from the associated drainage basin to examine
stressor-water quality relationships. The sampling captured broad ranges (1.5–2 orders of magnitude) in total phosphorus (TP),
total nitrogen (TN), dissolved inorganic nitrogen (DIN), total suspended solids (TSS), chlorophyll a (Chl a), and chloride; concentrations were strongly correlated with stressor metrics. Hierarchical partitioning and all-subsets
regression analyses were used to evaluate the independent influence of different stressor classes on water quality and to
identify best predictive models. Results showed that all categories of stress influenced water quality and that the relative
influence of different classes of disturbance varied among water quality parameters. Chloride exhibited the strongest relationships
with stressors followed in order by TN, Chl a, TP, TSS, and DIN. In general, coarse scale classification of wetlands by morphology (three wetland classes: riverine, protected,
open coastal) and biogeography (two ecoprovinces: Eastern Broadleaf Forest [EBF] and Laurentian Mixed Forest [LMF]) did not
improve predictive models. This study provides strong evidence of the link between water chemistry and human stress in Great
Lakes coastal wetlands and can be used to inform management efforts to improve water quality in Great Lakes coastal ecosystems. 相似文献
424.
To combat high rates of malnutrition in sub‐Saharan Africa, the UN Millennium Project has called for increased emphasis on technologies that explicitly link agricultural and nutritional components. While there is a large literature on the factors that influence household decisions to adopt new agricultural technologies with economic or environmental benefits, less is known about the factors that determine the uptake and continued use of agricultural technologies promoted exclusively for their health benefits. Using data from a 2004 survey in the Tamberma region of Togo and Benin, we identify factors that influence the adoption and disadoption of soybeans — a crop being promoted throughout West Africa for its high protein content. Similar to the literature on adoption of other sustainable agriculture technologies, we find that household preferences, resource endowments, and risk and uncertainty affect household decisions about soybeans. However, by analyzing decisions about initial uptake and continued cultivation separately, we uncover the importance of intrahousehold dynamics and experience with the soybean crop. To successfully address malnutrition through new agricultural technologies, researchers and rural extension agents should take a disaggregated view of technology adoption, seeking to identify and tailor their outreach to the different factors important at different stages of the dissemination process. 相似文献
425.
Erin A. Hopkins 《The Environmentalist》2016,36(2):209-216
The aim of this paper is to demonstrate the importance of accounting for environmental impacts in project feasibility. Cost–benefit analysis, a germane tool for measuring a project’s feasibility, can be utilized for projects with environmental consequences. This paper first provides a background on cost–benefit analysis as well as a background on environmental cost–benefit analysis. It then provides the steps taken in order to perform this type of analysis. With this cost–benefit analysis and environmental cost–benefit analysis framework in mind, six international case studies are reviewed to demonstrate how cost–benefit analysis is applied to various environmental projects around the world using different methods and from both a public and private sector viewpoint. Recommendations are then put forward to address the need for continued consideration and implementation of environmental impacts on cost–benefit analyses. 相似文献
426.
The triazine herbicide atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-trazine) was selected as a chemical stressor in an investigation of how toxicological responses of individually grown macrophytes reflect those of plants grown in more natural model populations and two-species communities. Phytotoxicity of the compound to Myriophyllumspicatum L. and Elodeacanadensis Michx. was assessed under semi-natural field conditions using 12000l outdoor microcosms. Exposure concentrations of 25, 50, 100, 250mugl(-1) plus controls (n=3) were evaluated, selected to fall within a range of concentrations known to produce a toxic response in the tested macrophytes, and effective concentrations required to cause a decrease in biomass endpoints by 10%, 25%, and 50% were estimated. The sensitivities of aquatic plants to atrazine did not differ substantially between planting systems, and few interactions between the effects of the planting method and atrazine effects on macrophyte biomass were detected using a two-way ANOVA. A lack of significant differences in biomass and relative growth rate measures between plants grown under the various test systems also indicated that interactions between and among species did not influence growth of plants in the model population and communities. Under these test conditions, the use of the "cone-tainer" method provided estimates of toxicity consistent with those from plants grown in assemblages, and potential interactions between plants were not found to modify the response of macrophytes to atrazine. 相似文献
427.
Effects of urbanization on the population structure of freshwater turtles across the United States 下载免费PDF全文
David R. Bowne Bradley J. Cosentino Laurel J. Anderson Christopher P. Bloch Sandra Cooke Patrick W. Crumrine Jason Dallas Alexandra Doran Jerald J. Dosch Daniel L. Druckenbrod Richard D. Durtsche Danielle Garneau Kristen S. Genet Todd S. Fredericksen Peter A. Kish Mary Beth Kolozsvary Frank T. Kuserk Erin S. Lindquist Carol Mankiewicz James G. March Timothy J. Muir K. Greg Murray Madeline N. Santulli Frank J. Sicignano Peter D. Smallwood Rebecca A. Urban Kathy Winnett‐Murray Craig R. Zimmermann 《Conservation biology》2018,32(5):1150-1161
Landscape‐scale alterations that accompany urbanization may negatively affect the population structure of wildlife species such as freshwater turtles. Changes to nesting sites and higher mortality rates due to vehicular collisions and increased predator populations may particularly affect immature turtles and mature female turtles. We hypothesized that the proportions of adult female and immature turtles in a population will negatively correlate with landscape urbanization. As a collaborative effort of the Ecological Research as Education Network (EREN), we sampled freshwater turtle populations in 11 states across the central and eastern United States. Contrary to expectations, we found a significant positive relationship between proportions of mature female painted turtles (Chrysemys picta) and urbanization. We did not detect a relationship between urbanization and proportions of immature turtles. Urbanization may alter the thermal environment of nesting sites such that more females are produced as urbanization increases. Our approach of creating a collaborative network of scientists and students at undergraduate institutions proved valuable in terms of testing our hypothesis over a large spatial scale while also allowing students to gain hands‐on experience in conservation science. 相似文献
428.
Summary. While the response to damage-released chemical alarm cues within the superorder Ostariophysi appears to be highly conserved
across species, it is generally observed that the intensity of response to heterospecific alarm cues decreases with increasing
phylogenetic distance. Recent studies have demonstrated that purine-N-oxides function as chemical alarm cues within Ostariophyian fishes and that the nitrogen-oxide functional group is conserved
as the chief molecular trigger. According to the purine-ratio hypothesis, these cross-species differences may be due to the
relative proportion of different carrier compounds associated with the nitrogen-oxide molecular trigger. To test this hypothesis,
we exposed glowlight tetras (Hemigrammus erythrozonus, Characidae, Ostariophysi) to one of five synthetic stimuli (hypoxanthine-3-N-oxide (H3NO), pyridine-N-oxide (PNO) or mixed stimuli of 75 % H3NO-25 % PNO, 50 % H3NO-50 % PNO, or 25 % H3NO-75 % PNO), natural conspecific chemical
alarm cue or a distilled water control. We quantified changes in shoal cohesion and vertical area use as species typical indicators
of an antipredator response. As predicted, response intensity decreased as the ratio of hypoxanthine-3-N-oxide to pyridine-N-oxide decreased and the strongest response was to natural alarm cue. These results suggest that species-specific carrier
compounds may account for the well-documented cross-species differences in the response to heterospecific alarm cues within
phylogenetically related taxa. 相似文献
429.
Matthew Gronquist Frank C. Schroeder Helen Ghiradella David Hill Erin M. McCoy Jerrold Meinwald Thomas Eisner 《Chemoecology》2006,16(1):39-43
Summary. Lucidota atra, a diurnal firefly, shares possession of defensive steroids (lucibufagins or LBGs) with nocturnal fireflies of the genus
Photinus. Photinus are protected against predators by their LBGs, but not against fireflies of the genus Photuris, the so-called firefly femmes fatales, which prey upon Photinus, thereby acquiring LBGs for their own defense. We propose that L. atra may have been prompted evolutionarily to become diurnal by the opportunity to avoid, thereby, being hunted by Photuris. Indeed, L. atra, if offered to Photuris, were eagerly devoured by the latter, which sequestered their LBG’s. In feeding on L. atra, Photuris may be driven by a gustatory affinity for LBGs. Persistent nocturnality might therefore have put L. atra at risk vis à vis Photuris. Diurnality freed the firefly from that risk, without compromising its defended status with respect to other predators. Possession
of LBGs may in fact account for L. atra’s unacceptability to birds and spiders. 相似文献
430.
Spatial statistical models that use flow and stream distance 总被引:6,自引:1,他引:6
Jay M. Ver Hoef Erin Peterson David Theobald 《Environmental and Ecological Statistics》2006,13(4):449-464
We develop spatial statistical models for stream networks that can estimate relationships between a response variable and
other covariates, make predictions at unsampled locations, and predict an average or total for a stream or a stream segment.
There have been very few attempts to develop valid spatial covariance models that incorporate flow, stream distance, or both.
The application of typical spatial autocovariance functions based on Euclidean distance, such as the spherical covariance
model, are not valid when using stream distance. In this paper we develop a large class of valid models that incorporate flow
and stream distance by using spatial moving averages. These methods integrate a moving average function, or kernel, against
a white noise process. By running the moving average function upstream from a location, we develop models that use flow, and
by construction they are valid models based on stream distance. We show that with proper weighting, many of the usual spatial
models based on Euclidean distance have a counterpart for stream networks. Using sulfate concentrations from an example data
set, the Maryland Biological Stream Survey (MBSS), we show that models using flow may be more appropriate than models that
only use stream distance. For the MBSS data set, we use restricted maximum likelihood to fit a valid covariance matrix that
uses flow and stream distance, and then we use this covariance matrix to estimate fixed effects and make kriging and block
kriging predictions.
Received: July 2005 / Revised: March 2006 相似文献