RESUMEN
Los mosaicos agrícolas han sido estudiados para comprender como contribuyen a mantener la riqueza de las especies según el tipo de matriz. Sin embargo, el estudio de la fenología de las especies dentro de estos ambientes ha sido dejado de lado. Por lo tanto mi objetivo con esta investigación fue analizar los cambios en la riqueza y abundancia de las especies de aves entre meses dentro de un mosaico periurbano agrícola tropical. Adicionalmente analicé si los cambios en la riqueza de las especies varían según su grado de dependencia por el bosque y el gremio alimenticio al que pertenecen. Realice muestreos mensuales del 2002 al 2010 dentro de una matriz de 30 ha dominada por potreros y cafetales, mezcladas con regeneración natural y zonas urbano-rurales. A lo largo de los muestreos anoté todos los individuos visto y escuchados de cada especie a lo largo de un trasecto de 3 km. Encontré que la riqueza de especies varió a lo largo de los meses, siendo mayor de enero a marzo (periodo seco del área de estudio) para todas las categorías de residencia (ej.: residentes, migratorias norteñas, sureñas, y altitudinales). Por tipo de gremio alimenticio la riqueza de especies aumento de enero a febrero para los frugívoros pequeños y en setiembre para los insectívoros; mientras que los otros gremios presentaron una riqueza similar de especies a lo largo del año. Por grado de dependencia de bosque solo las aves con dependencia moderada presentaron un aumento en su riqueza de enero a junio. El estudio reveló la ocurrencia de diferentes patrones de riqueza de aves a lo largo del año según el grado de dependencia del bosque, gremio alimenticio, y residencia en el país. Estas matrices poseen una riqueza alta de especies, pero en constante variación a lo largo del año, por lo que estos cambios en los patrones de riqueza deberían tomarse en cuenta para futuras políticas de conservación de dichos agroecosistemas.
Species richness inside agricultural landscape has been studied intensively and according to the type of landscape structure. However, the species phenology inside the mostly agricultural landscape is poorly understood. Therefore, my objective was to analyze species richness and individual abundance changes between months inside a semiurban agricultural landscape. Additionally, I analyzed if changes in species richness varied with the trophic guild and forest dependence of each species. From 2002 to 2010I I sampled 30 ha of coffee plantations and cattle land with natural successional regenerations and rural development. I recorded every individual listened and seen along a 3 km long transect once a month. The species richness changed between months and was higher between January and March (dry season in the study area) for all residence status (i.e., residents and north, south, and altitudinal migrants). Small frugivore species richness was higher between January and February, insectivore species richness was higher in September. The other food guilds had steady richness and abundance throughout the year. Species with a medium forest dependence showed higher species richness between January and June. Species richness phenology changed along the year depending on residence status, trophic guild, and forest dependence, a finding that should be taken into account in future conservation of this type of habitat.
RESUMEN
Forest roads have many kinds of direct and indirect effects such as physical, ecological, and socio-economic effects in landscape scale. In this study the relationship between forest road network and the structure of a multifunctionally planned forest landscape, in the south of Turkey was examined. The aim of the study was to determine whether or not the correlation between road network and landscape structure across a gradient of road density, categorical road/no road approach and landscape pattern data from the managed forest landscapes existed. It was concerned with three type polygons that were forest functioning patches, compartments, and stand patches and were associated with higher road density or existing of road network. To quantify the case, it was analyzed whether the spatial structure of forest patches adjacent to roads differs from the spatial structure of forest patches away from roads. GIS was used to integrate quantitative indices of landscape structure. There was little negatively significant relationship between road density and patch area/size, patch perimeter, and shape index of patton index (PI) and no correlation with patch number and Fractal Dimension (FD). The forest road network modified spatial pattern of patch shape through PI values. The road network increased the number of patch and decreased mean patch size. The existence of road network was more effective than topography index appearing of PI and FD in the roaded areas. It was indicated to potential reverse impacts of road network on spatial structure of forest compartments in terms of shape index (FD). Highest proportions of harvestable forest areas fall into roaded areas. The results define that road networks are effective on the spatial structure of forest landscape. The forest road network of study area has all probable ecological impacts of forest roads mentioned in context.
RESUMEN
The purpose of this study was to investigate the effects of different landscape structures on the understory Collembola community. Four different forest physiognomies were compared: Pinus spp. plantation, Eucalyptus spp. plantation, Araucaria angustifolia plantation, and a remaining native Araucaria forest. Three areas containing two sampling units (25 m x 2 m each) were selected in each forest physiognomy. Understory Collembola collection was done with a 1 x 1m canvas sheet held horizontally below the vegetation, which was beaten with a 1m long stick, seasonally from September 2003 to August 2004. We evaluated the influence of forest physiognomies on the abundance, richness and diversity of Collembola communities. It was also verified if the habitat structure of each physiognomy was associated with the composition of the Collembola community. A total number of 4,111 individuals were collected belonging to the families Entomobrydae and Tomocerida (Entomobryomorpha), and Sminthuridae (Symphypleona), and divided in 12 morphospecies. Pinus plantation presented the highest richness, abundance and diversity of Collembola and it was associated to diverse understory vegetation. The abundance of Entomobrydae and Sminthuridae was associated to the presence of bushes, while Tomoceridae abundance was associated to the presence of trees. The habitat structure, measured through understory vegetation density and composition, plays an important role on the determination of the structure and composition of the Collembola community.
O propósito deste estudo foi investigar os efeitos da estrutura do sub-bosque na comunidade de colêmbolos. Foram comparados quatro ambientes florestais distintos: plantações de Pinus spp., plantações de Eucalyptus spp., plantações de Araucaria angustifolia e áreas de floresta ombrófila nativa remanescente. Para cada fisionomia vegetal houve três áreas com duas unidades amostrais de 25 m × 2 m cada. As coletas foram realizadas com guarda-chuva entomológico, medindo 1 m × 1 m, no período de setembro de 2003 a agosto de 2004. Investigou-se se a abundância, a riqueza e a diversidade da comunidade de colêmbolos foram influenciadas pelas fisionomias vegetais. Também verificou-se se a estrutura do habitat de cada tipo de floresta teve associação com a composição da comunidade de colêmbolos. Foram coletados 4111 indivíduos, pertencentes às famílias Entomobryidae, Tomoceridae e Sminthuridae, divididos em 12 morfoespécies. A plantação de Pinus spp. apresentou maior riqueza, abundância e diversidade de colêmbolos, devido à maior quantidade de vegetação disponível no sub-bosque. A composição de colêmbolos esteve associada aos tipos vegetacionais, com Entomobryidae e Sminthuridae associados aos arbustos, e Tomoceridade às árvores. A estrutura do habitat, medida através da densidade e composição da vegetação do sub-bosque mostrou-se um fator importante na determinação da estrutura e composição da comunidade de Collembola.