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311.
Corace RG Shartell LM Schulte LA Brininger WL McDowell MK Kashian DM 《Environmental management》2012,49(2):359-371
To facilitate forest planning and management on National Wildlife Refuges, we synthesized multiple data sources to describe
land ownership patterns, land cover, landscape pattern, and changes in forest composition for four ecoregions and their associated
refuges of the Upper Midwest. We related observed patterns to ecological processes important for forest conservation and restoration,
with specific attention to refuge patterns of importance for forest landbirds of conservation priority. The large amount of
public land within the ecoregions (31–80%) suggests that opportunities exist for coarse and meso-scale approaches to conserving
and restoring ecological processes affecting the refuges, particularly historical fire regimes. Forests dominate both ecoregions
and refuges, but refuge forest patches are generally larger and more aggregated than in associated ecoregions. Broadleaf taxa
have increased in dominance in the ecoregions and displaced fire-dependent taxa such as pine (Pinus spp.) and other coniferous species; these changes in forest composition have likely also affected refuge forests. Despite
compositional changes, larger forest patches on refuges suggests that they may provide better habitat for area-sensitive forest
landbirds of mature, compositionally diverse forests than surrounding lands if management continues to promote increased patch
size. We reason that although fine-scale research and monitoring for species of conservation priority is important, broad
scale (ecoregional) assessments provide crucial context for effective forest and wildlife management in protected areas. 相似文献
312.
An inventory survey conducted to determine pesticide usage in a sub-catchment of the Nzoia sugarcane belt found a variety of pesticides used in the sub-catchment, which are reported in this paper. Analysis of soil samples from seven fallow experimental field plots left uncultivated for various periods from 3 to 96?months after cultivation with pesticide application indicated persistence of high concentrations of pesticide residues in the soil, with estimated soil half-lives (in years) ranging from 0.72 to 57.75 for organochlorines and from 1.13 to 8.25 for herbicides. The mean water concentrations (in ??g/L) of the pesticide residues in River Kuywa, which flows through the Nzoia Nucleus Estate sugarcane farms, ranged from 0.12 (lindane) to 1.36 (p,p??-DDT) for organochlorines and from 0.14 (atrazine) to 1.75 (diuron) for herbicides during the heavy rains period in August 2008 while the mean sediment concentrations (in ??g/g) ranged from 0.28 (lindane) to 1.87 (endrin) for organochlorines and 0.39 (hexazinone) to 4.61 (alachlor) for herbicides. The mean concentrations of residues in water during the light rain period in December 2008 ranged from 0.17 (p,p??-DDT) to 0.71 (aldrin) for organochlorines and 0.01 (atrazine) to 1.74 (alachlor) for herbicides while the sediment concentrations ranged from 0.38 (p,p??-DDT) to 1.145 (aldrin) for organochlorines and 0.74 (atrazine) to 1.98 (alachlor) for herbicides. Although DDT, aldrin, dieldrin, and endrin were not reported in the survey, their presence in the fallow experimental field plot soils and in River Kuywa water and sediment could indicate previous application, lack of recorded data or illegal usage since 1997 when they were banned. Notably, the concentrations of alachlor, diuron, cypermethrin, and hexazinone in the water column were substantial indicating their extensive usage and residual persistence in the sub-catchment, with subsequent wash-off and leaching into River Kuywa. The concentration levels of some of the individual pesticides exceeded the EU limit requirements for drinking water and indicated potential risk to humans and cattle if the water is used without treatment. 相似文献
313.
This study examined what factors best predict residents’ concerns about neighborhood safety. One-hundred and twenty-two participants were selected from a large, Midwestern metropolitan area. All participants lived in high crime areas. Participants completed a 22-item questionnaire that assessed their perceptions of neighborhood safety and vigilance. These items were clustered as: 1) Community care and vigilance, 2) neighborhood safety concerns, 3) physical incivilities, and 4) social incivilities. Police crime data were also used in the analyses. Our findings suggest that aspects of the broken window theory, collective efficacy, and place attachments/territoriality play a role in affecting residents’ concerns about neighborhood safety. 相似文献
314.
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
315.
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
316.
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
317.
Poudyal NC Johnson-Gaither C Goodrick S Bowker JM Gan J 《Environmental management》2012,49(3):623-635
Wildland fire in the South commands considerable attention, given the expanding wildland urban interface (WUI) across the
region. Much of this growth is propelled by higher income retirees and others desiring natural amenity residential settings.
However, population growth in the WUI increases the likelihood of wildfire fire ignition caused by people, as humans account
for 93% of all wildfires fires in the South. Coexisting with newly arrived, affluent WUI populations are working class, poor
or otherwise socially vulnerable populations. The latter groups typically experience greater losses from environmental disasters
such as wildfire because lower income residents are less likely to have established mitigation programs in place to help absorb
loss. We use geographically weighted regression to examine spatial variation in the association between social vulnerability
(SOVUL) and wildfire risk. In doing so, we identify “hot spots” or geographical clusters where SOVUL varies positively with
wildfire risk across six Southern states—Alabama, Arkansas, Florida, Georgia, Mississippi, and South Carolina. These clusters
may or may not be located in the WUI. These hot spots are most prevalent in South Carolina and Florida. Identification of
these population clusters can aid wildfire managers in deciding which communities to prioritize for mitigation programming. 相似文献
318.
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
319.
Enhanced 1,2-dichloroethane degradation in heavy metal co-contaminated wastewater undergoing biostimulation and bioaugmentation 总被引:1,自引:0,他引:1
Biostimulation, bioaugmentation and dual-bioaugmentation strategies were investigated in this study for efficient bioremediation of water co-contaminated with 1,2-dichloroethane (1,2-DCA) and heavy metals, in a microcosm set-up. 1,2-DCA concentration was periodically measured in the microcosms by gas chromatographic analysis of the headspace samples, while bacterial population and diversity were determined by standard plate count technique and Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR–DGGE) analysis, respectively. Dual-bioaugmentation, proved to be most effective exhibiting 22.43%, 26.54%, 19.58% and 30.49% increase in 1,2-DCA degradation in microcosms co-contaminated with As3+, Cd2+, Hg2+ and Pb2+, respectively, followed by bioaugmentation and biostimulation. Dual-bioaugmented microcosms also exhibited the highest increase in the biodegradation rate constant (k1) resulting in 1.76-, 2-, 1.7- and 2.1-fold increase in As3+, Cd2+, Hg2+ and Pb2+ co-contaminated microcosms respectively, compared to the untreated microcosms. Dominant bacterial strains obtained from the co-contaminated microcosms were found to belong to the genera Burkholderia, Pseudomonas, Bacillus, Enterobacter and Bradyrhizobium, previously reported for 1,2-DCA and other chlorinated compounds degradation. PCR–DGGE analysis revealed variation in microbial diversity over time in the different co-contaminated microcosms. Results obtained in this study have significant implications for developing innovative bioremediation strategies for treating water co-contaminated with chlorinated organics and heavy metals. 相似文献
320.
Organochlorine contamination in the Mediterranean coastal environment of Egypt was assessed based on 26 surface sediments samples collected from several locations on the Egyptian coast, including harbors, coastal lakes, bays, and estuaries. The distribution and potential ecological risk of contaminants is described. Organochlorine compounds (OCs) were widely distributed in the coastal environment of Egypt. Concentrations of PCBs, DDTs, and chloropyrifos ranged from 0.29 to 377 ng g−1 dw, 0.07 to 81.5 ng g−1 dw, and below the detection limit (DL) to 288 ng g−1 dw, respectively. Other organochlorinated pesticides (OCP) studied were 1–2 orders of magnitude lower. OCP and PCBs had higher concentrations at Burullus Lake, Abu Qir Bay, Alexandria Eastern Harbor, and El Max Bay compared to other sites. OCP and PCB contamination is higher in the vicinity of possible input sources such as shipping, industrial activities and urban areas. PCB congener profiles indicated they were derived from more than one commercially available mixture. The ratios of commercial chlordane and heptachlor metabolites indicate historical usage; however, DDT and HCHs inputs at several locations appear to be from recent usage. The concentrations of PCBs and DDTs are similar to those observed in sediments from coastal areas of the Mediterranean Sea. Ecotoxicological risk from DDTs and PCBs is greatest in Abu Qir Bay, Alexandria Harbor, and El-Max Bay. 相似文献