Net Precipitation in a Semideciduous Forest Fragment in Viçosa City, Mg

Abstract

-We aimed to evaluate the net precipitation and rainfall interception in a fragment of semideciduous forest at both early and advanced stages of regeneration in Viçosa city, Minas Gerais state, southeastern Brazil, from January 2012 through July 2013. Six plots were stablished, three in each regeneration stage area. For throughfall and stemflow quantification, 25 rain gauges and collectors were installed in trees having circumference higher than 15 cm, in each plot. An additional rain gauge was installed in an open area to quantify gross precipitation. Gross precipitation in the studied period was 1934 mm. On average, 79.3% and 72.6% of gross precipitation reached the soil via net precipitation in the areas at early and advanced regeneration stages, respectively. Rainfall interception by the forest canopy was higher in the advanced-regeneration area, corresponding to 25.8% of gross precipitation. In the early-regeneration area, on the other hand, rainfall interception accounted for 20.2% of gross precipitation. This suggests that more densely populated areas intercept more rainfall, and consequently have lower net precipitation. Thus, our study shows that rainwater distribution in forest environments changes according to their regeneration status. The replacement of species at different successional stages renders the water to follow different pathways, such as interception, stemflow, and throughfall. This information helps us understand that the succession process can be slow, yet it is the natural way of forest regeneration.Keywords: Forest hydrology; Watershed management; Interception. PRECIPITAÇÃO EFETIVA EM UM FRAGMENTO FLORESTAL ESTACIONAL SEMIDECIDUAL, VIÇOSA, MGRESUMO -Este trabalho teve por objetivo avaliar a precipitação efetiva e a interceptação da chuva em um fragmento de Floresta Estacional Semidecidual em estágio inicial e avançado de regeneração no Município de Viçosa, Minas Gerais, no período de janeiro de 2012 a julho de 2013. Foram demarcadas seis parcelas, três na área de regeneração inicial e três na área de regeneração avançada. Para quantificar a precipitação interna e o escoamento pelo tronco, foram instalados 25 pluviômetros em cada parcela e coletores nas árvores com circunferência > 15 cm. Além disso, um pluviômetro foi instalado em local aberto para quantificar a precipitação em aberto, que no período estudado foi igual a 1934 mm . Em média, 79,3% e 72,6% da precipitação em aberto, respectivamente, no estágio inicial e avançado de regeneração, chegam ao solo via precipitação efetiva. A interceptação pelo dossel florestal foi maior na área avançada do que na área inicial de regeneração, correspondendo, respectivamente, a 25,8% e 20,2% da precipitação em aberto, o que sugere que áreas mais densamente povoadas interceptam maior quantidade de chuva e, consequentemente, geram menor precipitação efetiva. Este estudo mostra então que a distribuição da água de chuva na floresta se modifica à medida que ela avança em regeneração. A substituição de espécies, em diferentes estágios 794

Interception of Rainfall in Successional Tropical Dry Forests in Brazil and Costa Rica

“…At MSSP, the trend was reversed, with the highest collecting capacity in the early stage (0.2%) and the lowest in intermediate and late stages (0.1%). These results contradict previous studies developed in Brazil in TDF that showed the same stemflow trend as the SRNP site [11,22]. Therefore, the results from MSSP were unforeseen and difficult to interpret in this study.…”

“…In the meantime, the effects of forest age or successional forest stages on rainfall interception have only been studied widely in forest plantations, temperate forests, and a few tropical rain forests [8,10]. The interception capacity of TDF successional stages has not been studied with the same effort, except in Costa Rica, Panama, and Brazil [11][12][13]. Therefore, the evaluation of rainfall interception by successional stages of TDF is indispensable for estimating the net rainfall that reaches the soil to provide better hydrological information to understand water balance and water fluxes at the level of forest ecosystems and landscapes.…”

The Dynamics of the Substrate Recovery of Waste Dumps in Calcary Mining Under Natural Regeneration

“…Another important factor regarding the presence of vegetation concerns rainfall interception by the canopy. The more advanced is the successional stage at which a forest is, the higher is rainfall interception by the canopy, as observed by Freitas et al (2016) in the evaluation of liquid precipitation and rainfall interception in a Seasonal Semideciduous Forest fragment at early and advanced stages of regeneration in Viçosa municipality, Minas Gerais state, southeastern Brazil.…”

Processos hidrológicos na bacia hidrográfica do Córrego Zerede em Timóteo-MG

“…O período chuvoso apresenta precipitações de elevadas intensidades, podendo provocar elevado escoamento superficial, a cobertura florestal reduz a intensidade de perda de água da bacia. Freitas et al, (2016) observaram que 18,1% da chuva precipitada foi interceptada pela copa das árvores e evaporada, o restante chega ao solo via precipitação interna, e através do escoamento pelo tronco, retardando a chegada de água até o solo, favorecendo a infiltração em um fragmento florestal em Viçosa-MG.…”