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Effects of habitat and landscape fragmentation on humans and biodiversity in densely populated landscapes 总被引:3,自引:0,他引:3
Manuela Di Giulio Rolf Holderegger Silvia Tobias 《Journal of environmental management》2009,90(10):2959-2968
Landscape fragmentation has often been seen as an only ecological problem. However, fragmentation also has a societal perspective, namely, in how humans perceive landscape fragmentation and in how landscape fragmentation potentially influences human well-being. These latter aspects have rarely been addressed so far. The inter-relationship of ecological and human dimensions of landscape fragmentation becomes especially evident when looking at the landscape where most people in industrial countries live, namely in suburban and urban areas. In these areas, landscape planners and environmental managers are confronted with the problem that landscapes should fullfil various functions, often with conflicting goals, e.g. nature reserves to enhance species richness vs. recreational areas for city-dwellers. We reviewed the ecological and sociological literature relevant for fragmentation in suburban and urban landscapes. In an interdisciplinary approach, we evaluated whether there are similarities and dissimilarities between the ecological and the human aspects of landscape fragmentation. We found important similarities. An example is that for both, humans and biodiversity, the loss of semi-natural areas has more drastic effects than the fragmentation of these areas per se. However, there are also relevant differences. We concluded that in densely populated landscapes a shift from responsive planning to an intentional design of environments is therefore needed. 相似文献
165.
PD Dr. Rolf Altenburger Dr. Dana Kühnel Martin Bittens Dr. Birgit Daus Dr. Werner Brack Dr. Florian Centler Prof. Dr. Hauke Harms Dr. Martin Thullner Dr. Lukas Y. Wick Prof. Dr. Kai-Uwe Goss Prof. Dr. Frank-Dieter Kopinke Dr. Katrin Mackenzie Dr. Anja Miltner PD Dr. Matthias Liess Dr. Rainer Wennrich Dr. Anne E. Berns PD Dr. Peter Burauel 《Environmental Sciences Europe》2010,22(4):502-506
166.
Dong W Xie G Miller TR Franklin MP Oxenberg TP Bouwer EJ Ball WP Halden RU 《Environmental pollution (Barking, Essex : 1987)》2006,142(1):132-142
Directly adjacent to the Chesapeake Bay lies the Aberdeen Proving Ground, a U.S. Army facility where testing of armor-piercing ammunitions has resulted in the deposition of >70,000 kg of depleted uranium (DU) to local soils and sediments. Results of previous environmental monitoring suggested limited mobilization in the impact area and no transport of DU into the nation's largest estuary. To determine if physical and biological reactions constitute mechanisms involved in limiting contaminant transport, the sorption and biotransformation behavior of the radionuclide was studied using geochemical modeling and laboratory microcosms (500 ppb U(VI) initially). An immediate decline in dissolved U(VI) concentrations was observed under both sterile and non-sterile conditions due to rapid association of U(VI) with natural organic matter in the sediment. Reduction of U(VI) to U(IV) occurred only in non-sterile microcosms. In the non-sterile samples, intrinsic bioreduction of uranium involved bacteria of the order Clostridiales and was only moderately enhanced by the addition of acetate (41% vs. 56% in 121 days). Overall, this study demonstrates that the migration of depleted uranium from the APG site into the Chesapeake Bay may be limited by a combination of processes that include rapid sorption of U(VI) species to natural organic matter, followed by slow, intrinsic bioreduction to U(IV). 相似文献
167.
Werth S Wagner HH Gugerli F Holderegger R Csencsics D Kalwij JM Scheidegger C 《Ecology》2006,87(8):2037-2046
Dispersal is a process critical for the dynamics and persistence of metapopulations, but it is difficult to quantify. It has been suggested that the old-forest lichen Lobaria pulmonaria is limited by insufficient dispersal ability. We analyzed 240 DNA extracts derived from snow samples by a L. pulmonaria-specific real-time PCR (polymerase chain reaction) assay of the ITS (internal transcribed spacer) region allowing for the discrimination among propagules originating from a single, isolated source tree or propagules originating from other locations. Samples that were detected as positives by real-time PCR were additionally genotyped for five L. pulmonaria microsatellite loci. Both molecular approaches demonstrated substantial dispersal from other than local sources. In a landscape approach, we additionally analyzed 240 snow samples with real-time PCR of ITS and detected propagules not only in forests where L. pulmonaria was present, but also in large unforested pasture areas and in forest patches where L. pulmonaria was not found. Monitoring of soredia of L. pulmonaria transplanted to maple bark after two vegetation periods showed high variance in growth among forest stands, but no significant differences among different transplantation treatments. Hence, it is probably not dispersal limitation that hinders colonization in the old-forest lichen L. pulmonaria, but ecological constraints at the stand level that can result in establishment limitation. Our study exemplifies that care has to be taken to adequately separate the effects of dispersal limitation from a limitation of establishment. 相似文献
168.
Biodiversity, distributions and adaptations of Arctic species in the context of environmental change 总被引:1,自引:0,他引:1
Callaghan TV Björn LO Chernov Y Chapin T Christensen TR Huntley B Ims RA Johansson M Jolly D Jonasson S Matveyeva N Panikov N Oechel W Shaver G Elster J Henttonen H Laine K Taulavuori K Taulavuori E Zöckler C 《Ambio》2004,33(7):404-417
The individual of a species is the basic unit which responds to climate and UV-B changes, and it responds over a wide range of time scales. The diversity of animal, plant and microbial species appears to be low in the Arctic, and decreases from the boreal forests to the polar deserts of the extreme North but primitive species are particularly abundant. This latitudinal decline is associated with an increase in super-dominant species that occupy a wide range of habitats. Climate warming is expected to reduce the abundance and restrict the ranges of such species and to affect species at their northern range boundaries more than in the South: some Arctic animal and plant specialists could face extinction. Species most likely to expand into tundra are boreal species that currently exist as outlier populations in the Arctic. Many plant species have characteristics that allow them to survive short snow-free growing seasons, low solar angles, permafrost and low soil temperatures, low nutrient availability and physical disturbance. Many of these characteristics are likely to limit species' responses to climate warming, but mainly because of poor competitive ability compared with potential immigrant species. Terrestrial Arctic animals possess many adaptations that enable them to persist under a wide range of temperatures in the Arctic. Many escape unfavorable weather and resource shortage by winter dormancy or by migration. The biotic environment of Arctic animal species is relatively simple with few enemies, competitors, diseases, parasites and available food resources. Terrestrial Arctic animals are likely to be most vulnerable to warmer and drier summers, climatic changes that interfere with migration routes and staging areas, altered snow conditions and freeze-thaw cycles in winter, climate-induced disruption of the seasonal timing of reproduction and development, and influx of new competitors, predators, parasites and diseases. Arctic microorganisms are also well adapted to the Arctic's climate: some can metabolize at temperatures down to -39 degrees C. Cyanobacteria and algae have a wide range of adaptive strategies that allow them to avoid, or at least minimize UV injury. Microorganisms can tolerate most environmental conditions and they have short generation times which can facilitate rapid adaptation to new environments. In contrast, Arctic plant and animal species are very likely to change their distributions rather than evolve significantly in response to warming. 相似文献
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Merz J Nakarmi G Shrestha S Dahal BM Dongol BS Schaffner M Shakya S Sharma S Weingartner R 《Environmental management》2004,34(1):26-37
Inadequacy and poor quality of water supply for domestic purposes is increasingly becoming a concern in rural catchments of the Middle Mountains of Nepal. Water quantity is an issue in pocket areas of these catchments, while water quality is subject to concern in most of the water sources. Microbiological contamination in particular poses a risk to human health. In addition, sediment pollution during the monsoon season is perceived as an issue by the local residents. Elevated phosphate and nitrate levels in many water sources indicate intensive interaction with surface water hailing from agricultural areas and human settlements. These water quantity and quality concerns in two watersheds of Nepal, the Jhikhu Khola and the Yarsha Khola watersheds, are not isolated cases. Similar problems are reported from other watersheds monitored under the People and Resource Dynamics in Mountain Watersheds of the Hindu Kush-Himalayas (PARDYP) project in China, India, and Pakistan and the literature of this region. 相似文献