34 research outputs found
Efeitos da umidade do solo e da cobertura vegetal na distribuição e abundância de Drosera montana (Droseraceae)
Comparações florísticas e estruturais entre comunidades de palmeiras em fragmentos de floresta primária e secundária da Área de Proteção Ambiental Raimundo Irineu Serra - Rio Branco, Acre, Brasil
O presente estudo compara a composição e estrutura das comunidades de palmeiras da Área de Proteção Ambiental Raimundo Irineu Serra - APARIS, localizada no perímetro urbano do Município de Rio Branco-Acre. Foram selecionadas três áreas de floresta secundária em estágios sucessionais distintos: 7,5 anos, 27,5 anos, 37,5 anos de idade, e um fragmento de floresta primária. Em cada área foram instaladas cinco parcelas de 20 X 20m, onde foram analisadas a composição florística, estrutura horizontal e estrutura populacional das palmeiras. Foram identificados 1.034 indivíduos, incluídos em 12 gêneros e 19 espécies de palmeiras. A área de floresta primária apresentou maior diversidade. Na análise da estrutura populacional de cada área, comprovamos a existência de uma escassez de plântulas (≤ 50 cm de altura) e adultos reprodutivos. A fragmentação alterou a composição e diminuiu a riqueza e a diversidade de palmeiras na área da APARIS, enquanto, está favorecendo a dominância de certas espécies como A. phalerata.This study compares the composition and structure of palm communities in fragments of secondary and primary forest within the Raimundo Irineu Serra Environmental Protection Area (APARIS), located at the urban perimeter of Rio Branco, Acre. To evaluate the palm communities, we selected secondary forest areas belonging to three distinct successional stages: 7.5 years; 27.5 years, 37.5 years, and a primary forest fragment. In each forest type we installed five 20 x 20 m plots, where we analyzed floristic composition, vegetation structure, and population demography of all palm species (Arecaceae). In all, we identified 1034 palm individuals, including 12 genera, 19 species. Primary forest exhibited the greatest palm diversity. Structural analysis of each area revealed a scarcity of seedlings (≤ 50 cm tall) and reproductive adults. Fragmentation altered the composition and decreased the richness and diversity of palms within the APARIS, while at the same time, favoring the dominance of certain species, such as A. phalerata
Caracterização fitossociológica de um remanescente de Floresta Ombrófila mista em Guarapuava, PR
Conservation priorities of useful plants from different techniques of collection and analysis of ethnobotanical data
This study analyzes three methods of data analysis to verify which one would be more appropriate to get information aiming the conservation, selecting the use value (VU) inventory in situ and conservation property index (IPC). It was developed in in Northeast Brazil, via interviewed householders (46 informants). The VU was calculated considering only the effective use of plants; the inventory in situ was made through the frequency of species occurrence in homes; and the IPC combining ethnobotanical and phytossociological data. It was observed a similar cast of the indicated species by VU and inventory in situ, being different from the IPC cast. As this study sought to analyze the best technique for species identification which were needing conservationist actions, and obtained different results among the chosen methods. It has been suggested the use of methods that unite in their analysis both ethnobotanical and ecological aspects, like in the plants list from the priority index of conservation, which demonstrated to be more efficient to identify rare species in the local vegetation. The VU and the inventory in situ are more efficient to identify the most known and used species in the communities, however without analyzing these plants in the local vegetation
Estrutura e composição de um trecho de Mata Atlântica no Parque Estadual das Fontes do Ipiranga, São Paulo, SP, Brasil
Soziologie und Synökologie von Foraminiferen und Thecamöben aus dem Brackwasser des Balize-Deltas, Louisiana
Remote forest refugia for Fijian wildlife
On Pacific islands non-native rats and mongooses threaten many native species. In Fiji we compared visitation rates of rats and mongooses at bait stations and measured biomass of leaf-litter invertebrates to assess the relative predation pressure from these species in forest areas at different distances from the forest edge. Forest areas over 5 km from the forest edge had significantly fewer baits encountered by rats or mongooses than did natural forest areas nearer agricultural and urban habitats. Remote forest areas may function as a last refuge for island species threatened by predation from non-native rats and mongooses. The biomass of leaf-litter invertebrates in remote forest areas was higher, indicating a refuge effect for some taxa targeted by rats and mongooses. Protection of the few remaining large blocks of natural forests on Pacific islands may be the most cost-effective approach for conserving many island endemics threatened by rats and mongooses. Logging roads can compromise this refuge effect by acting as dispersal routes for rats into natural forests
