نتایج جستجو برای: distance from forest
تعداد نتایج: 5771037 فیلتر نتایج به سال:
The objective of this paper is to discuss approaches and issues related to modelling stand dynamics for multi-cohort forest management in eastern Canadian boreal forests. In these forests, the interval between wildfires can be rather long, and the development of natural forest stands may include the establishment, growth and mortality of several cohorts of trees. Later cohorts are characterised...
Due to the nutritional content and commercial value of its seeds, Bertholletia excelsa is one of the most important species exploited in the Amazon region. The species is hermaphroditic, insect pollinated, and its seeds are dispersed by barochory and animals. Because the fruit set is dependent on natural pollinator activity, gene flow plays a key role in fruit production. However, to date, ther...
one of the most visible aspects of a forest stand structure is the spatial patterns of trees. competition affects on forest structure and its understanding is important, when the purpose of forest management is to imitate the dynamic of natural ecosystems. for this purpose, an unmanaged intact forest was selected with 26 hectares area. all chestnut leaf oak (quercus castaneifolia) trees with a ...
In 1995, wolves Canis lupus were reintroduced into Yellowstone National Park, USA, where they began to prey on ungulate species. In response to this new predation risk by wolves, we predicted that the two main ungulate species, elk Cervus elaphus and bison Bison bison, should compensate by reducing their use of riskier open meadows and increasing their use of safer forest. Additionally we predi...
population management of exploited species requires information on absolute density and abundance through reliable survey methods. the baseline information is further needed for population dynamics studies and determination of conservation status. the current population size of pheasant is totally unknown, because there is no official attempt to estimate population size in previous years. in th...
Studies of the effects of patch size and isolation on plant species density have yielded contrasting results. However, much of the available evidence comes from relatively recent anthropogenic forest fragments which have not reached equilibrium between extinction and immigration. This is a critical issue because the theory clearly states that only when equilibrium has been reached can the numbe...
BACKGROUND AND AIMS This study sought genetic evidence of long-term isolation in populations of Monstera adansonii var. klotzschiana (Araceae), a herbaceous, probably outbreeding, humid forest hemi-epiphyte, in the brejo forests of Ceará (north-east Brazil), and clarification of their relationships with populations in Amazonia and the Atlantic forest of Brazil. METHODS Within-population genet...
conservation of biodiversity in protected areas will be more challenging if local communities are heavily dependent on them for various products and subsistence needs. this study estimated forest dependency and identified factors influencing dependency for households living around kasane forest reserve (kfr). data collected from 237 households were analyzed using logistic regression model. logi...
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