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21.
Jonathan P Freeman Thomas J Stohlgren Molly E Hunter Philip N Omi Erik J Martinson Geneva W Chong Cynthia S Brown 《Ecological applications》2007,17(6):1656-1665
Fire is a natural part of most forest ecosystems in the western United States, but its effects on nonnative plant invasion have only recently been studied. Also, forest managers are engaging in fuel reduction projects to lessen fire severity, often without considering potential negative ecological consequences such as nonnative plant species introductions. Increased availability of light, nutrients, and bare ground have all been associated with high-severity fires and fuel treatments and are known to aid in the establishment of nonnative plant species. We use vegetation and environmental data collected after wildfires at seven sites in coniferous forests in the western United States to study responses of nonnative plants to wildfire. We compared burned vs. unburned plots and plots treated with mechanical thinning and/or prescribed burning vs. untreated plots for nonnative plant species richness and cover and used correlation analyses to infer the effect of abiotic site conditions on invasibility. Wildfire was responsible for significant increases in nonnative species richness and cover, and a significant decrease in native cover. Mechanical thinning and prescribed fire fuel treatments were associated with significant changes in plant species composition at some sites. Treatment effects across sites were minimal and inconclusive due to significant site and site x treatment interaction effects caused by variation between sites including differences in treatment and fire severities and initial conditions (e.g., nonnative species sources). We used canonical correspondence analysis (CCA) to determine what combinations of environmental variables best explained patterns of nonnative plant species richness and cover. Variables related to fire severity, soil nutrients, and elevation explained most of the variation in species composition. Nonnative species were generally associated with sites with higher fire severity, elevation, percentage of bare ground, and lower soil nutrient levels and lower canopy cover. Early assessments of postfire stand conditions can guide rapid responses to nonnative plant invasions. 相似文献
22.
Quantifying species recovery and conservation success to develop an IUCN Green List of Species 下载免费PDF全文
H. Resit Akçakaya Elizabeth L. Bennett Thomas M. Brooks Molly K. Grace Anna Heath Simon Hedges Craig Hilton‐Taylor Michael Hoffmann David A. Keith Barney Long David P. Mallon Erik Meijaard E.J. Milner‐Gulland Ana S.L. Rodrigues Jon Paul Rodriguez P.J. Stephenson Simon N. Stuart Richard P. Young 《Conservation biology》2018,32(5):1128-1138
Stopping declines in biodiversity is critically important, but it is only a first step toward achieving more ambitious conservation goals. The absence of an objective and practical definition of species recovery that is applicable across taxonomic groups leads to inconsistent targets in recovery plans and frustrates reporting and maximization of conservation impact. We devised a framework for comprehensively assessing species recovery and conservation success. We propose a definition of a fully recovered species that emphasizes viability, ecological functionality, and representation; and use counterfactual approaches to quantify degree of recovery. This allowed us to calculate a set of 4 conservation metrics that demonstrate impacts of conservation efforts to date (conservation legacy); identify dependence of a species on conservation actions (conservation dependence); quantify expected gains resulting from conservation action in the medium term (conservation gain); and specify requirements to achieve maximum plausible recovery over the long term (recovery potential). These metrics can incentivize the establishment and achievement of ambitious conservation targets. We illustrate their use by applying the framework to a vertebrate, an invertebrate, and a woody and an herbaceous plant. Our approach is a preliminary framework for an International Union for Conservation of Nature (IUCN) Green List of Species, which was mandated by a resolution of IUCN members in 2012. Although there are several challenges in applying our proposed framework to a wide range of species, we believe its further development, implementation, and integration with the IUCN Red List of Threatened Species will help catalyze a positive and ambitious vision for conservation that will drive sustained conservation action. 相似文献
23.
Cokriging optimization of monitoring network configuration based on fuzzy and non-fuzzy variogram evaluation 总被引:3,自引:0,他引:3
Passarella G Vurro M D'Agostino V Barcelona MJ 《Environmental monitoring and assessment》2003,82(1):1-21
A number of optimization approaches regarding monitoring networkdesign and sampling optimization procedures have been reported inthe literature. Cokriging Estimation Variance (CEV) is a usefuloptimization tool to determine the influence of the spatial configuration of monitoring networks on parameter estimations. Itwas used in order to derive a reduced configuration of a nitrateconcentration monitoring well network. The reliability of the reduced monitoring configuration suffers from the uncertainties caused by the variographer's choices and several inherent assumptions. These uncertainties can be described considering thevariogram parameters as fuzzy numbers and the uncertainties by means of membership functions.Fuzzy and non-fuzzy approaches were used to evaluate differencesamong well network configurations. Both approaches permitted estimates of acceptable levels of information loss for nitrate concentrations in the monitoring network of the aquifer of the Plain of Modena, Northern Italy. The fuzzy approach was found torequire considerably more computational time and numbers of wellsat comparable level of information loss. 相似文献
24.
Molly M. Pohl 《Journal of the American Water Resources Association》2002,38(6):1511-1519
ABSTRACT: Over 76,000 dams have been constructed on American rivers to provide services such as flood protection, water storage, hydroelectric power, and navigation. Although most dams continue to provide sufficient benefits to retain the structure, dam removal is becoming increasingly common. This study involved the construction of a dam removal database to analyze spatial and temporal trends in dam removal. The data included information on 417 cases of dismantled American dams, 153 with known rationales for removal. Database analysis indicated that the leading purposes for dismantling structures are safety concerns and interest in environmental restoration. There is substantial geographic variability in dam removal rationales, with California leading in razing dams for environmental purposes, and Wisconsin leading in economic and safety rationales. States with substantial removals tend to have programs that support and fund dam razing. Although removals for safety reasons have been increasing steadily in the past three decades, environmental removals made a rather dramatic and sudden entry into the dam removal arena in the 1990s. Analysis of spatial and temporal trends in dam razing are of particular significance given the likely increase in dam removals in the 21st Century. 相似文献
25.
Gavin McDonald Molly Wilson Diogo Veríssimo Rebecca Twohey Michaela Clemence Dean Apistar Stephen Box Paul Butler Fel Cesar Cadiz Stuart J. Campbell Courtney Cox Micah Effron Steve Gaines Raymond Jakub Roquelito H. Mancao Pablo T. Rojas Rocky Sanchez Tirona Gabriel Vianna 《Conservation biology》2020,34(5):1176-1189
Small-scale fisheries are an important livelihood and primary protein source for coastal communities in many of the poorest regions in the world, yet many are overfished and thus require effective and scalable management solutions. Positive ecological and socioeconomic responses to management typically lag behind immediate costs borne by fishers from fishing pressure reductions necessary for fisheries recovery. These short-term costs challenge the long-term success of these interventions. However, social marketing may increase perceptions of management benefits before ecological and socioeconomic benefits are fully realized, driving new social norms and ultimately long-term sustainable behavior change. By conducting underwater visual surveys to quantify ecological conditions and by conducting household surveys with community members to quantify their perceptions of management support and socioeconomic conditions, we assessed the impact of a standardized small-scale fisheries management intervention that was implemented across 41 sites in Brazil, Indonesia, and the Philippines. The intervention combines TURF reserves (community-based territorial use rights for fishing coupled with no-take marine reserves) with locally tailored social-marketing behavior change campaigns. Leveraging data across 22 indicators and 4 survey types, along with data from 3 control sites, we found that ecological and socioeconomic impacts varied and that communities supported the intervention and were already changing their fishing practices. These results suggest that communities were developing new social norms and fishing more sustainably before long-term ecological and socioeconomic benefits of fisheries management materialized. 相似文献
26.
The Adaptation for Conservation Targets (ACT) Framework: A Tool for Incorporating Climate Change into Natural Resource Management 总被引:1,自引:0,他引:1
MS Cross ES Zavaleta D Bachelet ML Brooks CA Enquist E Fleishman LJ Graumlich CR Groves L Hannah L Hansen G Hayward M Koopman JJ Lawler J Malcolm J Nordgren B Petersen EL Rowland D Scott SL Shafer MR Shaw GM Tabor 《Environmental management》2012,50(3):341-351
As natural resource management agencies and conservation organizations seek guidance on responding to climate change, myriad potential actions and strategies have been proposed for increasing the long-term viability of some attributes of natural systems. Managers need practical tools for selecting among these actions and strategies to develop a tailored management approach for specific targets at a given location. We developed and present one such tool, the participatory Adaptation for Conservation Targets (ACT) framework, which considers the effects of climate change in the development of management actions for particular species, ecosystems and ecological functions. Our framework is based on the premise that effective adaptation of management to climate change can rely on local knowledge of an ecosystem and does not necessarily require detailed projections of climate change or its effects. We illustrate the ACT framework by applying it to an ecological function in the Greater Yellowstone Ecosystem (Montana, Wyoming, and Idaho, USA)-water flows in the upper Yellowstone River. We suggest that the ACT framework is a practical tool for initiating adaptation planning, and for generating and communicating specific management interventions given an increasingly altered, yet uncertain, climate. 相似文献
27.
Modeling the Spatially Varying Water Balance Processes in a Semiarid Mountainous Watershed of Idaho1
Benjamin T. Stratton Venakataramana Sridhar Molly M. Gribb James P. McNamara Balaji Narasimhan 《Journal of the American Water Resources Association》2009,45(6):1390-1408
Stratton, Benjamin T., Venakataramana Sridhar, Molly M. Gribb, James P. McNamara, and Balaji Narasimhan, 2009. Modeling the Spatially Varying Water Balance Processes in a Semiarid Mountainous Watershed of Idaho. Journal of the American Water Resources Association (JAWRA) 45(6):1390‐1408. Abstract: The distributed Soil Water Assessment Tool (SWAT) hydrologic model was applied to a research watershed, the Dry Creek Experimental Watershed, near Boise Idaho to investigate its water balance components both temporally and spatially. Calibrating and validating SWAT is necessary to enable our understanding of the water balance components in this semiarid watershed. Daily streamflow data from four streamflow gages were used for calibration and validation of the model. Monthly estimates of streamflow during the calibration phase by SWAT produced satisfactory results with a Nash Sutcliffe coefficient of model efficiency 0.79. Since it is a continuous simulation model, as opposed to an event‐based model, it demonstrated the limited ability in capturing both streamflow and soil moisture for selected rain‐on‐snow (ROS) events during the validation period between 2005 and 2007. Especially, soil moisture was generally underestimated compared with observations from two monitoring pits. However, our implementation of SWAT showed that seasonal and annual water balance partitioning of precipitation into evapotranspiration, streamflow, soil moisture, and drainage was not only possible but closely followed the trends of a typical semiarid watershed in the intermountain west. This study highlights the necessity for better techniques to precisely identify and drive the model with commonly observed climatic inversion‐related snowmelt or ROS weather events. Estimation of key parameters pertaining to soil (e.g., available water content and saturated hydraulic conductivity), snow (e.g., lapse rates, melting), and vegetation (e.g., leaf area index and maximum canopy index) using additional field observations in the watershed is critical for better prediction. 相似文献
28.
A small subsurface ion mobility spectrometer (SS-IMS) was constructed and tested with several environmental contaminants to determine its potential for monitoring gaseous volatile organic compounds in the vadose zone. Trichloroethylene (TCE) and tetrachloroethylene (PCE) were detected and separated in IMS for the first time. Detection limits as low as 1 part per billion volume-to-volume (ppb(v)) were observed. Reduced mobility (K(0)) values were reported for 11 environmental contaminants. These data demonstrated the potential of ion mobility spectrometry as a viable technology for detecting and separating environmental soil-gas contaminants in the field, which may lead to a practical and simple approach for long-term monitoring of contaminated soils. 相似文献
29.
Iride Passarella Irene Elia Barbara Guarino Giancarlo Bourlot Michèle Nègre 《Journal of environmental science and health. Part. B》2013,48(2):137-143
The dissipation of the fungicides captan, cyprodinil, fludioxonil, dithianon, and tebuconazole and of the insecticides chlorpyrifos, fenitrothion, and malathion was studied, following a single treatment of different cultivars of pears, apples, and peaches. The study was conducted in northern Italy, over two successive growing seasons (2004 and 2005). The treatments were performed by the farmers involved, in line with their usual practice. At various time intervals from treatment to harvest, representative samples of fruit were collected and analyzed for pesticide residues. In some cases, concentrations lower than the maximum residue levels (MRLs) were found immediately after treatment. In all trials a rapid decline in pesticide concentrations was observed leading to residues at harvest greatly below the MRLs. 相似文献
30.
An adaptive management approach is necessary but not sufficient to address the long-term challenges of the Greater Yellowstone
Ecosystem (GYE). Adaptive management, in turn, has its own particular challenges, of which we focus on two: science input, and stakeholder engagement. In order to frame our discussion and subsequent recommendations, we place the current management difficulties into their
historical context, with special emphasis on the 1990 Vision document, which attempted a broad synthesis of management goals for the ecosystem. After examining these two key challenges
in the context of the GYE, we make several recommendations that would allow for more effective ecosystem management in the
long term. First, we recommend adoption of the GYE as a site for long-term science research and monitoring with an emphasis
on integrative research, long-term federal funding, and public dissemination of data. Second, we conclude that a clearer prioritization
of legislative mandates would allow for more flexible ecosystem management in the GYE, a region where conflicting mandates
have historically led to litigation antithetical to effective ecosystem management. Finally, we recommend a renewed attempt
at an updated Vision for the Future that engages stakeholders (including local landholders) substantively from the outset. 相似文献