Precipitação efetiva em diferentes formações florestais na floresta nacional de ipanema

Abstract

RESUMO -O presente trabalho foi conduzido na Floresta Nacional de Ipanema, unidade de conservação de uso sustentável localizada no município de Iperó-SP, com o objetivo de quantificar e comparar as frações de precipitação efetiva e interceptação da chuva em três povoamentos florestais distintos, sendo eles: Eucalyptus cloeziana, Pinus caribea var. hondurensis e Floresta Estacional Semidecidual. Para tanto, realizou-se o monitoramento das variáveis precipitação interna, escoamento pelo tronco, interceptação e precipitação em aberto em cada formação florestal, ao longo do período de novembro de 2009 à maio de 2010. O estudo revelou a precipitação efetiva de 86,2%, 85,0% e 77,2%; interceptação de 13,8%, 15,0% e 22,8% em relação à precipitação em aberto em Eucalyptus cloeziana, Pinus caribea var. hondurensis e Floresta Estacional Semidecidual, respectivamente. A influência dos povoamentos na distribuição da chuva apresentou diferença significativa somente para o processo de interceptação entre Floresta Estacional Semidecidual e os demais.Palavras-chave: Precipitação interna; Escoamento pelo tronco; Hidrologia florestal. NET PRECIPITATION IN DIFFERENT FOREST FRAGMENTS OF IPANEMA NATIONAL FOREST ABSTRACT -This study was conducted in the National

PARTITIONING OF RAINFALL IN EXPERIMENTAL PLANTATIONS OF Eucalyptus urophylla AND Pinus elliottii

“…Thus, the amount of gross rainfall was responsible for 99% of the throughfall variation. The high correlation among these variables has already been documented in the literature (LIMA, 1976;MOURA et al, 2012;GASPAROTO et al, 2014). For stemflow, the R² values ranged from moderate (0.6139 for eucalyptus and 0.6447 for pine) to high (0.8011 for eucalyptus and 0.8170 for pine).…”

“…The mean percentages of throughfall, stemflow, and interception for pine were intermediate to those in studies with species of this genus in Brazil (GIGLIO, KOBIYAMA, 2013, TONELLO et al, 2014. For eucalyptus, interception losses were much lower than the minimum limit of 12% presented by Giglio and Kobiyama (2013).…”

“…From nine articles, authors recorded the following ranges of throughfall, stemflow and interception related to rainfall: 71.2% to 90.4%, 1.0% to 7.4%, and 6.6% to 21.4%, respectively, in pine plantations; and 78.2% to 84.0%, 1.0% to 8.1%, and 12.2% to 15.6% in eucalyptus plantations, respectively. Studies after this review found values of throughfall, stemflow and interception at 84.0%, 1% and 15.0%, respectively, for P. caribaea; 85.2%, 1.0% and 13.8%, respectively, for E. cloeziana (TONELLO et al, 2014); 81%, 5% and 14%, respectively, for E. urograndis (TREVISAN et al, 2012); and 78.1%, 11.1% and 14.6%, respectively, for E. grandis (SARI et al, 2016).…”

Trees Lose Their Leaves Later in Agroforestry Systems

“…This is because only a small part of the water intercepted by the trees is absorbed by the leaves, most of it flows down the trunk and reaches the ground. The interception of rainwater by the canopy can vary from 13 to 22% of the precipitated total [19] and for precipitations of less than 11.0 mm the intercepted water does not even reach the soil, due to its rapid evaporation [20]. From the second half of July, when there are no more rainfall, the Vw30 in SF starts to reduce gradually, reaching the lowest values at the end of September (0.24 cm 3 cm -3 ) (Figure 2), which are equivalent to the values found at the same depth in the AGP (Figure 3).…”

Relationships between rainfall and throughfall in a secondary forest in southeastern Brazil: an evaluation of different statistical models

“…In addition, it is also possible to obtain parameters for the modelling of other hydrological processes from linear models (PYPKER et al, 2005;ZOU et al, 2015), such as canopy water storage capacity, the fraction of direct TF, amongst others. For example, the inverse value of the parameter a obtained by the linear model in the present study (Table 2) represents the canopy water storage capacity, indicating the RF depth needed to saturate the canopy and promote TF (LORENZON; DIAS; LEITE, 2013;STAELENS et al, 2008;TONELLO et al, 2014). Although the linear and power models have similar capabilities to explain the variation of TF mm , the use of linear models is recommended, since the parameters of these models can be used in more detailed analyzes of hydrological modelling, and allow comparison among the results obtained at different locations.…”