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151.
基于MSPA与MCR模型的余江县生态网络构建基于MSPA与MCR模型的余江县生态网络构建 总被引:4,自引:0,他引:4
在我国社会经济快速发展的背景下,城市化进程的不断推进导致城市生态斑块日益减少,生态环境问题正在逐年增加,构建生态网络是改善城市生态环境与服务功能的有效方法之一。以余江县为研究区,采用形态学空间格局分析(MSPA)方法和景观指数法,提取对生态网络具有重要意义的生态源地,并基于MCR模型构建综合阻力面,采用最小成本路径方法生成潜在廊道,再基于重力模型、中介中心度等对关键廊道及踏脚石斑块进行识别并提取,从而构建研究区潜在生态网络。结果表明:MSPA方法能够与MCR模型有机的结合,通过定量的分析识别出研究区潜在生态廊道,并根据斑块的中介作用选定踏脚石斑块,明确研究区景观要素的保护优先度,将景观中的潜在生态源地及廊道作为生态网络构建的主要依据,能够更加科学地为余江县生态网络的构建提供指导,同时也可为其他区域提供参考。 相似文献
152.
Anna Maria J?nsson Olle Anderbrant Jennie Holmér Jacob Johansson Guy Schurgers Glenn P. Svensson Henrik G. Smith 《Ambio》2015,44(3):249-255
In recent years, climate impact assessments of relevance to the agricultural and forestry sectors have received considerable attention. Current ecosystem models commonly capture the effect of a warmer climate on biomass production, but they rarely sufficiently capture potential losses caused by pests, pathogens and extreme weather events. In addition, alternative management regimes may not be integrated in the models. A way to improve the quality of climate impact assessments is to increase the science–stakeholder collaboration, and in a two-way dialog link empirical experience and impact modelling with policy and strategies for sustainable management. In this paper we give a brief overview of different ecosystem modelling methods, discuss how to include ecological and management aspects, and highlight the importance of science–stakeholder communication. By this, we hope to stimulate a discussion among the science–stakeholder communities on how to quantify the potential for climate change adaptation by improving the realism in the models. 相似文献
153.
A method to estimate the impact of clear-cutting on nutrient concentrations in boreal headwater streams 总被引:1,自引:0,他引:1
Large-scale forestry operations, like clear-cutting, may impair surface water quality if not done with environmental considerations in mind. Catchment and country level estimates of nutrient loads from forestry are generally based on specific export values, i.e., changes in annual exports due to the implemented forestry operations expressed in kg ha−1. We introduce here a specific concentration approach as a method to estimate the impact of clear-cutting on nutrient concentrations and export in headwater streams. This new method is potentially a more dynamic and flexible tool to estimate nutrient loads caused by forestry, because variation in annual runoff can be taken into account in load assessments. We combined water quality data from eight boreal headwater catchment pairs located in Finland and Sweden, where the effect of clear-cutting on stream water quality has been studied experimentally. Statistically significant specific concentration values could be produced for total nitrogen, nitrate, ammonium, and phosphate. The significant increases in the concentrations of these nutrients occurred between 2 and 6 years after clear-cutting. Significant specific concentration values could not be produced for total phosphorus and total organic carbon with the whole dataset, although in some single studies significant increases in their concentrations after clear-cutting were observed. The presented method enables taking into account variation in runoff, temporal dynamics of effects, and the proportional size of the treated area in load calculations. The number of existing studies considering large site-specific variation in responses to clear-cutting is small, and therefore further empirical studies are needed to improve predictive capabilities of the specific concentration values. 相似文献
154.
Identification of vulnerable arable areas to phosphorus (P) losses is needed to effectively implement mitigation measures. Indicators for source (soil test P, STP), potential mobilization by erosion (soil dispersion), and transport (unit-stream power length-slope, LS) risks were used to screen the vulnerability to suspended solids (SS) and P losses in two contrasting catchments regarding topography, soil textural distribution, and STP. Soils in the first catchment ranged from loamy sand to clay loam, while clay soils were dominant in the second catchment. Long-term SS and total P losses were higher in the second catchment in spite of significantly lower topsoil STP. A higher proportion of areas in the second catchment were identified with higher risk due to the significantly higher risk of overland flow generation (LS) and a significantly higher mobilization risk in the soil dispersion laboratory tests. A simple screening method was presented to improve the placement of mitigation measures. 相似文献
155.
Eliana S. Da Silva Vanessa Prevot Claude Forano Pascal Wong-Wah-Chung Hugh D. Burrows Mohamed Sarakha 《Environmental science and pollution research international》2014,21(19):11218-11227
Decatungstate W10O32 4? was efficiently intercalated between the layers of three-dimensionally ordered macroporous Mg2Al-layered double hydroxide. The structural and textural properties of as-prepared intercalated compound were characterized using different solid-state characterization techniques such as X-ray powder diffraction, FTIR and Raman spectroscopies and electronic microscopy. The photocatalytic properties of immobilized W10O32 4? within Mg2Al structure were investigated using 2-(1-naphthyl) acetamide (NAD) as a model of pesticide. The influence of different parameters such as amount of catalyst, pH and oxygen concentration were investigated. An optimal NAD degradation was obtained for a photocatalyst concentration of 60 mg l?1. Under our experimental conditions, this heterogeneous photocatalyst induces photodegradation of 60 % of NAD after 17 h of irradiation at 365 nm and at pH 6.6. Interestingly, pesticide photodegradation leads to the mineralization of substrates to H2O and CO2 and the photocatalyst can be recycled and reused without any loss of activity over four cycles. 相似文献
156.
Rogério Luiz Da Silva Claudia Pereira Da silva Sandro Navickiene 《Journal of environmental science and health. Part. B》2013,48(6):589-594
An extraction method based on matrix solid-phase dispersion was developed to determine pirimicarb, methyl parathion, malathion, procymidone, α -endosulfan and β -endosulfan in lettuce using gas chromatography-mass spectrometry. The best results were obtained using 4.0 g of lettuce, 2.0 g of silica as dispersant sorbent, 0.1 g of activated carbon as clean up sorbent and acetonitrile as eluting solvent. The method was validated using lettuce samples fortified with pesticides at six different concentration levels (0.1 to 2.0 mg/kg). Average recoveries (7 replicates) ranged from 50 to 120 %, with relative standard deviations between 0.6 and 8.0 %. Detection and quantification limits for lettuce ranged from 0.01 to 0.02 mg/kg and 0.04 to 0.10 mg/kg, respectively. 相似文献
157.
Bellmore JR Baxter CV Ray AM Denny L Tardy K Galloway E 《Environmental management》2012,49(3):734-750
Pre-restoration studies typically focus on physical habitat, rather than the food-base that supports aquatic species. However,
both food and habitat are necessary to support the species that habitat restoration is frequently aimed at recovering. Here
we evaluate if and how the productivity of the food-base that supports fish production is impaired in a dredge-mined floodplain
within the Yankee Fork Salmon River (YFSR), Idaho (USA); a site where past restoration has occurred and where more has been
proposed to help recover anadromous salmonids. Utilizing an ecosystem approach, we found that the dredged segment had comparable
terrestrial leaf and invertebrate inputs, aquatic primary producer biomass, and production of aquatic invertebrates relative
to five reference floodplains. Thus, the food-base in the dredged segment did not necessarily appear impaired. On the other
hand, we observed that off-channel aquatic habitats were frequently important to productivity in reference floodplains, and
the connection of these habitats in the dredged segment via previous restoration increased invertebrate productivity by 58%.
However, using a simple bioenergetic model, we estimated that the invertebrate food-base was at least 4× larger than present
demand for food by fish in dredged and reference segments. In the context of salmon recovery efforts, this observation questions
whether additional food-base productivity provided by further habitat restoration would be warranted in the YFSR. Together,
our findings highlight the importance of studies that assess the aquatic food-base, and emphasize the need for more robust
ecosystem models that evaluate factors potentially limiting fish populations that are the target of restoration. 相似文献
158.
Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida 总被引:1,自引:0,他引:1
Hogan DM Labiosa W Pearlstine L Hallac D Strong D Hearn P Bernknopf R 《Environmental management》2012,49(2):502-515
Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban
development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land
use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects
at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio
Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve
communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated
through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened
and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential,
and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1)
assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative
impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion
of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may
result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation
of potential future LU patterns and incorporate EV into decision making. 相似文献
159.
Santoro R Jucker T Prisco I Carboni M Battisti C Acosta AT 《Environmental management》2012,49(3):534-542
Sandy coastlines are sensitive ecosystems where human activities can have considerable negative impacts. In particular, trampling
by beach visitors is a disturbance that affects dune vegetation both at the species and community level. In this study we
assess the effects of the limitation of human trampling on dune vegetation in a coastal protected area of Central Italy. We
compare plant species diversity in two recently fenced sectors with that of an unfenced area (and therefore subject to human
trampling) using rarefaction curves and a diversity/dominance approach during a two year study period. Our results indicate
that limiting human trampling seems to be a key factor in driving changes in the plant diversity of dune systems. In 2007
the regression lines of species abundance as a function of rank showed steep slopes and high Y-intercept values in all sectors, indicating a comparable level of stress and dominance across the entire study site. On the
contrary, in 2009 the regression lines of the two fenced sectors clearly diverge from that of the open sector, showing less
steep slopes. This change in the slopes of the tendency lines, evidenced by the diversity/dominance diagrams and related to
an increase in species diversity, suggests the recovery of plant communities in the two fences between 2007 and 2009. In general,
plant communities subject to trampling tended to be poorer in species and less structured, since only dominant and tolerant
plant species persisted. Furthermore, limiting trampling appears to have produced positive changes in the dune vegetation
assemblage after a period of only two years. These results are encouraging for the management of coastal dune systems. They
highlight how a simple and cost-effective management strategy, based on passive recovery conservation measures (i.e., fence
building), can be a quick (1–2 years) and effective method for improving and safeguarding the diversity of dune plant communities. 相似文献
160.
Community-based collaborative groups involved in public natural resource management are assuming greater roles in planning,
project implementation, and monitoring. This entails the capacity of collaborative groups to develop and sustain new organizational
structures, processes, and strategies, yet there is a lack of understanding what constitutes collaborative capacity. In this
paper, we present a framework for assessing collaborative capacities associated with community-based public forest management
in the US. The framework is inductively derived from case study research and observations of 30 federal forest-related collaborative
efforts. Categories were cross-referenced with literature on collaboration across a variety of contexts. The framework focuses
on six arenas of collaborative action: (1) organizing, (2) learning, (3) deciding, (4) acting, (5) evaluating, and (6) legitimizing.
Within each arena are capacities expressed through three levels of social agency: individuals, the collaborative group itself,
and participating or external organizations. The framework provides a language and set of organizing principles for understanding
and assessing collaborative capacity in the context of community-based public forest management. The framework allows groups
to assess what capacities they already have and what more is needed. It also provides a way for organizations supporting collaboratives
to target investments in building and sustaining their collaborative capacities. The framework can be used by researchers
as a set of independent variables against which to measure collaborative outcomes across a large population of collaborative
efforts. 相似文献