Produção e decomposição da serrapilheira em um ecossistema semiárido do nordeste brasileiro: variação temporal e espacial e efeito da fauna de solo sobre a serrapilheira

• Autor(a) principal: Araújo, Virginia Farias Pereira de
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/tede/4108
• topic: Caatinga; Precipitação; Evapotranspiração; Estrutura da vegetação; Bolsas de serrapilheira; Naftalina; Fauna de solo; Caatinga; Rainfall; Evapotranspiration; Vegetation structure; Litter bags; Naphthalene; Soil fauna; CIENCIAS BIOLOGICAS::ZOOLOGIA

Studies related to litter dynamics are important to comprehend decomposing deciduos material, nutrients cycling, succession patterns, ecological disturbance and environmental variables interactions in terrestrial ecosystems. In opposition to Caatinga's degradation speed, a lack of studies related to litter production dynamics is observed. Thus, this study aimed to evaluate climatic factors (rainfall and evapotranspiration) and vegetation effects over temporal and spatial dynamics of litter production in Brazilian Northeastern's semiarid. A phytosociologic survey was performed in Paraiba's Cariri in 12 sampling areas. Two 1 m2 collectors (with 0,15 m3) were placed about 50 m distant from each other in order to estimate litter monthly production between November 2009 and 2011. Litter deposition values observed in this study varied between 3430 and 4600 kg.ha-1.year-1. Litter production was significantly bigger in the second year of survey and it varied between months in both years. Intra-annual variation was positive to total litter production, showing peaks of litterfall in dry period about three or four months after the greatest rates of monthly rainfall. While reproductive structures and branches corresponded to 14% and miscellany from 3% to 5%, leaves, which represented more than 60% of the total, corresponded to the predominant part of litter. Litter production was significantly different between areas so as each of its parts. The density of plant species, vegetation height and trunk diameter at ground were responsible for 79% of annual litter production in those different areas. Results reveal that litter production in Caatinga have a spatiotemporal heterogeneity, which is related to climate and vegetation and must provide effects over substratum in edaphic microorganisms activities and, consequently, in edaphic conditions and nutrients availability. Therefore, in Caatinga, associations of spatial variations in microhabitats conditions and inter-annual variations could interfere in the offering period of floral resource, substrate nutrients availability and, possibly, in the behavior of substrate-using animals.