نتایج جستجو برای: forest and pastures
تعداد نتایج: 16850860 فیلتر نتایج به سال:
Throughout the eastern United States, plant species distributions and community patterns have developed in response to heterogeneous environmental conditions and a wide range of historical factors, including complex histories of natural and anthropogenic disturbance. Despite increased recognition of the importance of disturbance in determining forest composition and structure, few studies have ...
The factors influencing weight changes during the grazing season of Brown Swiss autumn-calving cows and Brown Swiss and Pirenaica spring-calving cows and their calves were studied over an 8-yr period in Spanish mountain conditions. The data set comprised 552 annual production cycles of cows that calved in two consecutive years. The animals grazed on alpine ranges during the summer and on forest...
Silvopastoral systems are traditional components of the landscape in the Swiss Jura Mountains, and are promising approaches for the sustainable management of mountain areas worldwide. Due to complex vegetation dynamics, pasturewoodlands are very vulnerable to the currently occurring land use and climate changes. Therefore, management requires integrative long-term predictions of successional tr...
Habitat fragmentation is thought to lower the viability of tropical trees by disrupting their mutualisms with native pollinators. However, in this study, Dinizia excelsa (Fabaceae), a canopy-emergent tree, was found to thrive in Amazonian pastures and forest fragments even in the absence of native pollinators. Canopy observations indicated that African honeybees (Apis mellifera scutellata) were...
The objective of this paper is to assess the changes in soil physical and chemical properties resulting from conversion native forest pasture secondary state Santa Catarina, Brazil. Seven forest–pasture successional stages were identified using aerial photographs satellite images acquired 1957, 1978, 2008. Successional coded as FFF, FPF, PFF, PPF, FPP, FFP, PPP, where first, second, third lette...
The conversion of native forests into pastures is still a common practice in Brazil. Abandoned have great potential for natural regeneration and therefore could play an important role meeting the enormous demand forest restoration. Few studies, however, investigated extent to which spatially-structured environmental variables community structure are correlated with variation species abundance r...
New Zealand Journal of Ecology (1998) 22(2): 189-196 ©New Zealand Ecological Society limitation on the sustainability of pastoral land use in New Zealand and this issue has been heightened by recent resource management legislation (Blaschke et al., 1992). In contrast, there have been few investigations on the effects of forest removal on the New Zealand soil fauna (Yeates, 1991). Contraction in...
Deforestation and fragmentation are major components of global change; both are contributing to the rapid loss of tropical forest area with important implications for ecosystem functioning and biodiversity conservation. The forests of South Ecuador are a biological 'hotspot' due to their high diversity and endemism levels. We examined the deforestation and fragmentation patterns in this area of...
The aim of this work was to evaluate the occurrence of arbuscular mycorrhizal fungi (AMF) species diversity in soil samples from the Amazon region under distinct land use systems (Forest, Old Secondary Forest, Young Secondary Forest, Agroforestry systems, Crops and Pasture) using two distinct trap cultures. Traps established using Sorghum sudanense and Vigna unguiculata (at Universidade Regiona...
The impacts of forest fragmentation on both reproductive biology and genetic diversity of native plant species is hardly understood, despite some studies have analyzed this current worldwide problem. Since this constitutes one of the main threats to seasonal semi-deciduous forests in Southeastern Brazil, we investigated the reproductive success and the genetic diversity of a distylous, understo...
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