Paulo Cesar Moura da Silva

Análise comparativa da produção de serapilheira em fragmentos arbóreos e arbustivos em área de caatinga na FLONA de Açu-RN

The litter is the most superficial layer of soil in a forest environment, its composed by Leaves, Twigs, seeds, roots and remains, which together have innumerous importance in establishing and balancing the ecosystem. The purpose of this work was to evaluate the litterfall in two different areas, shrubs and treed, in a preserved area of biom caatinga. This research was carried out in the Acu Nacional Forest - FLONA/ ACU-RN. The FLONA was divided in two different areas, in relation to aspects and vegetation postage, for shrubs and trees. 12 litter collections were made. Each area had 20 wooden traps installed measuring 1.0m X 1.0m X 0.15m (0.15m3), with 1mm nylon mesh, distributed at random in the Flonas area. The material collected was put in paper bags, named and taken to the UERN botanic lab. The material was oven-dried at 70o C during 72h and weighed. The results were expressed in g/m2 and submitted to the analysis of variance and test t (p<0.05). The source results showed that the average annual litterfall was estimated at 2,984.5 Kg/ha, with an estimated 3,384 Kg/ha in tree vegetation and 2,580 kg/ha in shrub vegetation. The litterfall in caatinga bioma was similar to other sources in the caatinga areas. The highest values of litterfall were observed after rainy seasons and the beginning of dry seasons in the researched area.

Variabilidade Espacial e Temporal das Precipitações para a Microrregião de Pau dos Ferros-RN (Spatial and Temporal Variability of Precipitation for the Microregion of Pau dos Ferros-RN)

A precipitacao pluviometrica apresenta importância para os estudos climaticos, pois quando ocorrida em excesso, ocasiona implicacoes para os setores produtivos da sociedade tanto economico e social, causando enchentes, assoreamento dos rios, e quedas de barreiras. O presente trabalho teve o objetivo de realizar uma analise da variabilidade espacial e temporal da precipitacao pluvial media e da maxima media anual, para a microrregiao de Pau dos Ferros-RN, por meio de uma geotecnologia, especificamente modelagem espacial. Para realizacao do processamento dos dados e confeccao das cartas foi utilizado o SIG (Sistema de Informacao Geografica), onde os postos meteorologicos dos dezessete municipios foram georreferenciados para projecao cartografica UTM, DATUM WGS 84, fuso (zona) 24. O metodo de interpolacao utilizado foi o inverso do quadrado da distância (IQD). Para verificar a acuracia da interpolacao, foi calculado o erro medio quadratico (RMSE - Root Mean Square Error). O erro medio quadratico (RMSE) apresentou um valor de 0,06544 mm para a precipitacao media anual, ja para a precipitacao media maxima anual foi 0,00764 mm. O interpolador do inverso do quadrado da distância mostrou-se bastante eficaz para especializar a precipitacao pluviometrica. O conhecimento da variabilidade espacial das precipitacoes anuais e maximas ao longo da serie historica em estudo permitem auxiliar no manejo das praticas agricolas e no planejamento de obras de engenharia hidraulica. ABSTRACT Rainfall has importance for climate studies, because when it occurs in excess, leads to implications for the productive sectors of society both economic and social, causing flooding, siltation of rivers and landslides. This study aimed to perform an analysis of the variability spatial and temporal of rainfall and average maximum annual average for the micro region of Pau do Ferros-RN, through a geotechnology, specifically spatial modeling. To perform the data processing and manufacturing of the cards was used GIS (Geographic Information System), where the weather stations of the seventeen counties were georeferenced cartographic projection UTM, WGS 84 DATUM, zone (zone) 24. The interpolation method used was the inverse square of the distance (QID). To verify the accuracy of the interpolation, we calculated the root mean square error (RMSE). The root mean square error (RMSE) had a value of 10.6 mm for daily rainfall average annual, as for the daily rainfall average maximum annual was 12.8 mm. The knowledge of the spatial variability of annual rainfall and maximum along the historical series study to assisting in the management of agricultural practices and planning of hydraulic engineering. Keywords: precipitation, distribution, spatial modeling.