نتایج جستجو برای: forest surveys
تعداد نتایج: 183820 فیلتر نتایج به سال:
To test for direct and indirect effects of a top predator on three lower trophic levels, we conducted two multiyear predator addition experiments in a tropical wet forest. Periodic additions of a top predator (predatory clerid beetle) to a wet forest understory shrub caused a reduction in the predatory beetle's prey (a predatory ant), increased herbivory, and reduced leaf area of the plant. The...
Project Goals and Objectives – The objective of the proposed surveys and analyses are to (1) produce a quantitative baseline characterization of the structure of kelp forest ecosystems in five of the marine protected areas (MPAs) recently established by the MLPA Initiative in the NCCSR, (2) provide a quantitative comparison between the kelp forest ecosystems in these MPAs and associated referen...
Aim We used alien plant species introduced to a botanic garden to investigate the relative importance of species traits (leaf traits, dispersal syndrome) and introduction characteristics (propagule pressure, residence time and distance to forest) in explain ing establishment success in surrounding tropical forest. We also used invasion scores from a weed risk assessment protocol as an independe...
Identification and mapping of the significant alterations are the main objectives of the exploration geochemical surveys. The field study is time-consuming and costly to produce the classified maps. Therefore, the processing of remotely sensed data, which provide timely and multi-band (multi-layer) data, can be substituted for the field study. In this study, the ASTER imagery is used for altera...
On the diversity and richness of understory bryophytes at Nectandra Cloud Forest Reserve, Costa Rica
BACKGROUND A survey of the understory bryophytes in the Nectandra Cloud Forest Preserve yielded 1083 specimens distributed among 55 families, represented by 74 genera of mosses, 75 genera of liverworts and 3 of hornworts. We studied and analyzed the bryophytic distribution on six types of substrates: 1) corticolous, 2) epiphyllous, 3) saxicolous, 4) terricolous, 5) aquatic and 6) lignicolous. T...
Valued attributes of forests encourage surveys and inventories of multiple attributes that need quantitative definition and integration followed by comprehensible presentation. The Forest Identity defines the four attributes of expanse, growing stock, biomass and carbon in terms of measurable forest area (A), forest density (D), biomass to growing stock ratio (B), and carbon concentration (C). ...
Endemic Hawaiian Drosophilidae, a radiation of nearly 1000 species including 13 federally listed as endangered, occur mostly in intact native forest, 500-1500 m above sea level. But their persistence in disturbed forest and agricultural areas has not been documented. Thus, control efforts for agricultural pests may impact endemic species if previously undocumented refugia in agricultural areas ...
A recent publication hypothesized that deep snowfall can limit fisher (Martes pennanti) populations, and high fisher populations limit marten populations (M. americana). These hypotheses were evaluated by comparing the historic (1919-1924) and current (1989-1994) distributions of both Martes species in California to current snowfall distributions and forest types presumed to be habitats for eac...
Madagascar is a biodiversity hotspot threatened by habitat loss, which is detrimental to the future survival of forest-dwelling herpetofauna. For conservation purposes, it is essential to determine how species respond to different types of anthropogenic habitat alteration. We conducted standardized field surveys (a variation of visual encounter survey) to assess species richness, abundance and ...
The thamin (Cervus eldi) is an endangered species of deer whose present range is greatly reduced from its original distribution covering the deciduous forests throughout south-east Asia. We mapped the present distribution of thamin using ground surveys and tied this information to habitat types derived from satellite images in order to detect patterns that might indicate the landscape features ...
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