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排序方式: 共有319条查询结果,搜索用时 15 毫秒
261.
为了弄清南岳自然保护区内藤本植物资源现状,对该区内藤本植物进行了多样性调查研究。结果表明:野生藤本植物共计59科129属282种(含变种),其中蕨类植物有3科5属6种,双子叶植物有50科112属250种,单子叶植物有6科12属26种,裸子植物缺乏。该区地理成分复杂多样,科级地理成分有8个分布型,属级地理成分有12个分布型,种级地理成分有11个分布型,均以热带成分为主,温带成分占有较大比例,说明该区热带成分向温带渗透和过度的性质。藤本植物的生活型,以木质藤本占优势,为6064%,草质藤本占39.36%,一年生藤本占1441%。藤本植物的攀援类型分为4型9亚型,以缠绕类为主,占37〖JP2〗94%;其次为吸固类,占2305%,又可分为不定根类、吸盘类和寄生类3亚型;卷曲类占2093%,又可分为须卷类、柄卷类和枝卷类3亚型;刺蔓类最少占1809%,又可分为枝蔓类和钩刺类2亚型。该区藤本植物资源丰富,在垂直绿化与经济开发上具有十分广阔的前景 相似文献
262.
263.
David Mouillot Alexis Titeux Christophe Migon Valérie Sandroni Jean-Pierre Frodello Denise Viale 《Environmental Modeling and Assessment》2000,5(4):185-192
The lagoon of Biguglia (northeastern Corsica) is one of a number Nature Reserve. Anthropogenic activities are increasing over its watershed however. The present study aims to examine the state of health of the lagoon with the example of two pollutants (Cd and Cu). Water samples were collected in spring and summer 1997. The trace metal fluxes between the various compartments were measured. Transfer processes from the watershed to the lagoon were also examined. The temporal evolution of Cd and Cu content is assessed on the one hand by comparing the present data with former reference work (1992). On the other hand, a 5-box model is implemented in order to reduce the complex functioning of the lagoon to a system of differential equations. With the help of a numerical resolution method, the increase of metallic concentration levels is estimated since 1992. On the basis of 1997 data, two hypotheses are compared. The hypothesis that takes into account a growing increase of anthropogenic activities on the watershed gives, by extrapolation, results that are closer to field measurements. However, even with this hypothesis, the cadmium content in the lagoon is underestimated. This may signify that for this metal the evolution of the lagoon pollution is more important than a linear increase. 相似文献
264.
We develop a reserve design strategy to maximize the probability of species persistence predicted by a stochastic, individual-based,
metapopulation model. Because the population model does not fit exact optimization procedures, our strategy involves deriving
promising solutions from theory, obtaining promising solutions from a simulation optimization heuristic, and determining the
best of the promising solutions using a multiple-comparison statistical test. We use the strategy to address a problem of
allocating limited resources to new and existing reserves. The best reserve design depends on emigration, dispersal mortality,
and probabilities of movement between reserves. When movement probabilities are symmetric, the best design is to expand a
subset of reserves to equal size to exhaust the habitat budget. When movement probabilities are not symmetric, the best design
does not expand reserves to equal size and is strongly affected by movement probabilities and emigration rates. We use commercial
simulation software to obtain our results. 相似文献
265.
Three studies used digital color photographs to compare responses to natural scenes, skylines after dark, and skylines during the day (seven of each). Study 1 had 59 respondents rate the pleasantness of each scene. They gave similar ratings to Night Skylines and Natural Scenes, and rated each as more pleasant than the Day Skylines. Study 2 had 56 other participants choose from each of seven sets of each kind of scene the one they would most like to have as a framed print in their home or office, and to report the reasons. Participants chose Night Skylines most often, followed by Natural Scenes and then Day Skylines. While participants most often picked attractive as a reason for their choice, those who chose Night Skylines also picked exciting as the reason, and those who picked Natural Scenes also picked relaxing or peaceful as a reason. Study 3 obtained ratings of selected formal features of each scene. The 23 judges rated the Natural scenes as more natural, orderly, open, and curvilinear, less complex, and as having smoother transitions than either Day or Night Skylines; and they judged the Night Skylines as higher in complexity but lower in order than Day Skylines. The results suggest that preferences in relation to the scene categories may well depend on a mix of their formal characteristics and their content. 相似文献
266.
A multi-scaled model for biodiversity conservation in forests was introduced in Sweden 30 years ago, which makes it a pioneer
example of an integrated ecosystem approach. Trees are set aside for biodiversity purposes at multiple scale levels varying
from individual trees to areas of thousands of hectares, with landowner responsibility at the lowest level and with increasing
state involvement at higher levels. Ecological theory supports the multi-scaled approach, and retention efforts at every harvest
occasion stimulate landowners’ interest in conservation. We argue that the model has large advantages but that in a future
with intensified forestry and global warming, development based on more progressive thinking is necessary to maintain and
increase biodiversity. Suggestions for the future include joint planning for several forest owners, consideration of cost-effectiveness,
accepting opportunistic work models, adjusting retention levels to stand and landscape composition, introduction of temporary
reserves, creation of “receiver habitats” for species escaping climate change, and protection of young forests. 相似文献
267.
Meaningful human–nature interactions can counteract the extinction of experience and positively influence people’s nature relatedness, health and wellbeing. In this study, we explored urban wild food foraging to understand how best to enable human-nature interactions in cities by means of foraging. Using a structured questionnaire, a total of 458 residents of Vienna, Austria were surveyed. Sixty-four percent of visitors of public urban green spaces previously foraged for wild food species, whereas foraging frequencies were related to the targeted plant species and their life forms. People who foraged more frequently had greater nature relatedness, more childhood foraging experiences and lived on the outskirts of the city, but their socio-demographic backgrounds were heterogeneous. Social acceptance and lack of access to wild foods were perceived to be barriers. To promote nature relatedness through urban foraging, the legal framework, access to low-contamination foraging areas, availability of wild foods and social acceptance need to be improved.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01648-1. 相似文献
268.
Local people's perceptions as decision support for protected area management in Wolong Biosphere Reserve, China 总被引:5,自引:0,他引:5
This paper examines local people's knowledge, attitudes and perceptions towards Wolong Biosphere Reserve (WBR) and its management policies. Pertinent data were collected through a questionnaire survey and group discussions. This study revealed that local people's perceptions were affected by many factors, including education, gender, residence location, household size and acreage of land owned. Although most respondents had limited knowledge about WBR because of their absence in WBR management, they held a positive attitude towards WBR. An in-depth analysis of their attitudes and perceptions showed that two potential conflicts might affect biodiversity conservation and protected area management. One of them was the imbalance between the limited cropland holding and the oversupply of the labor force, and the other one was the increase in electricity price versus the decrease in economic incentives for the Natural Forest Protection Project. The study also revealed that relocation was considered unacceptable to most respondents. However, those residing far from the main road were willing to relocate more than those near the main road. Based on our studies, some recommendations are given for improvement of WBR management. 相似文献
269.
Gölcük Nature Park (GNP) is an area protected by law in Turkey. It is an important nature park with rich flora, fauna, geomorphologic forms, landscape features, and recreational potential in the region. However, GNP does not have a recreation management plan. The purpose of this study was to determine the actual natural, cultural, and visual resources of GNP, determine the most suitable recreational sites with multiple factors, evaluate the demands and tendencies of visitors, and suggest recreational activities and facilities for the most suitable sites of GNP. However, it was also conceived as leading to a recreational plan and design of GNP in the future and identifying the entire appropriate and current data of GNP with the creation of various maps. This study used multifactor analysis to determine the most suitable recreation sites of GNP. Used recreation factors were established including degree of slope, proximity to water resources, accessibility, elevation, vegetation, soil, climate, aspect, current cultural facilities, visual values, and some limiting factors in accordance with the characteristics of GNP. Weighting and suitability values of factors were determined by 30 local expert surveys. All obtained data were evaluated and integrated in the Geographical Information Systems base. Obtained maps were overlapped. Thus, recreational suitability zones map were created manually. However, the demands and behaviours from visitor surveys in GNP were focused on the most suitable recreation sites of the park. Finally, 10% of GNP was identified as the most suitable sites for recreational use. Various recreational facilities and activities (including picnicking, sports facilities and playgrounds, camping sites, walking paths, food and local outlets, etc.) were recommended for nine of the most suitable areas on the proposed recreational map. 相似文献
270.
Environmental education and financial support of nature conservation are considered among the primary components of the environmentalist
dimension of ecotourism. The potential of environmental education calls for enhancing visitor environmental knowledge and
prompting change of visitor behavior. The present study addressed the evaluation of the environmentalist dimension of ecotourism
in the Dadia Forest Reserve. The first objective of the research was to study the influence of variables determined prior
to the visit, namely, visitor and visit characteristics, visitor environmental information sources, visitor pro-environmental
behavior, and visitation goals, on variables determined during the visit, that is, visitor participation in and satisfaction
from ecotourism activities. The second objective was to study the effect of selected variables on visitor knowledge and behavior
intentions. Visitor participation in and satisfaction from ecotourism activities were primarily controlled by visit characteristics.
Levels of visitor knowledge were quite satisfactory; however, coherence among knowledge items was rather loose. On the other
hand, behavior intention items revealed the highest possible degree of coherence, which should be attributed to the pervasive
influence of visitor satisfaction from watching birds at the Bird Observatory within the Dadia Forest Reserve. Ecotourism
activities, during which the main part of environmental knowledge was offered, exerted no effect on visitor knowledge; all
the same, they significantly influenced visitor behavior intentions. Overall, visitor behavior intentions revealed a considerable
potential of financing environmental protection and providing voluntary work in the frame of the environmental management
of the Dadia Forest Reserve. 相似文献