Kelly Cristina Tonello

ESCOAMENTO DA ÁGUA DA CHUVA PELO TRONCO DAS ÁRVORES EM UMA FLORESTA ESTACIONAL SEMIDECIDUAL

This study was conducted at the Estacao de Pesquisas, Treinamento e Educacao Ambiental Mata do Paraiso, located in Vicosa, Minas Gerais, Brazil, and its goal is to evaluate the stem flow of the trees of a fragment of Atlantic Forest, from August 2009 to March 2011. In order to quantify the stem flow six plots were demarcated, measuring 10 m x 10 m. In each plot polyurethane based collectors were adapted on the stem of the tree with circumference 15.0 cm. A rain gauge was installed in an open area to quantify the water directly from the rain. In addition, a qualitative analysis of the trees was performed regarding the stem flow, evaluating the quality of the stem and canopy, its location inside the forest and the level of lianas infestation. Considering the whole period of analysis, 75 measurements were performed. In the plots where the stem flow was quantified, 126 trees were sampled, distributed in 29 families and 59 species. The gross precipitation reached 2391.63 mm and the stem flow represented 31.59 mm, or 1.32% of the gross precipitation. The species with the greater stem flow was Euterpe edulis, with a stem flow average of 637.00 liters. Among the species with the greater stem flow, 73.91% are located in the lower stratum of the forest, showing that some species have a type of morphological adaptation to capture rainwater.

Precipitação efetiva em diferentes formações florestais na floresta nacional de ipanema

RESUMO – O presente trabalho foi conduzido na Floresta Nacional de Ipanema, unidade de conservacao de uso sustentavel localizada no municipio de Ipero-SP, com o objetivo de quantificar e comparar as fracoes de precipitacao efetiva e interceptacao da chuva em tres povoamentos florestais distintos, sendo eles: Eucalyptus cloeziana, Pinus caribea var. hondurensis e Floresta Estacional Semidecidual. Para tanto, realizou-se o monitoramento das variaveis precipitacao interna, escoamento pelo tronco, interceptacao e precipitacao em aberto em cada formacao florestal, ao longo do periodo de novembro de 2009 a maio de 2010. O estudo revelou a precipitacao efetiva de 86,2%, 85,0% e 77,2%; interceptacao de 13,8%, 15,0% e 22,8% em relacao a precipitacao em aberto em Eucalyptus cloeziana, Pinus caribea var. hondurensis e Floresta Estacional Semidecidual, respectivamente. A influencia dos povoamentos na distribuicao da chuva apresentou diferenca significativa somente para o processo de interceptacao entre Floresta Estacional Semidecidual e os demais.

NET PRECIPITATION IN A SEMIDECIDUOUS FOREST FRAGMENT IN VIÇOSA CITY, MG

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 Vicosa 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.

THE INFLUENCE OF THE NUMBER OF LEAVES IN THE MACAÚBA PALM Acrocomia aculeata (Jacq.) Lodd. ex Mart. ON THE CORRELATION BETWEEN STEMFLOW AND GROSS PRECIPITATION

The macauba palm (Acrocomia aculeata) has a great production potential of oil and is an important alternative to diversify agricultural production. In view of the hypothesis that the species may provide a positive contribution to the hydrological processes in a watershed, we aimed to assess the influence of the number of leaves per macauba plant on the correlation between stemflow and gross precipitation. We installed three rain gauges to monitor gross precipitation in an experimental area, and stemflow collectors on the stem of eight macauba plants therein having 10, 13, 18, and 22 leaves. Linear regression equations were obtained, which enabled us to estimate the minimum rainfall volume required for the occurrence of stemflow. A strong positive linear correlation was observed between stemflow and gross precipitation, regardless of the number of leaves per plant. The morphological characteristics of the macauba palm favor rainfall interception, relatively high stemflow values being shown even in young plants. The funnel-shaped crown enabled the conduction of large rainfall volumes to the stem, thus resulting in the occurrence of stemflow even with light precipitations.

Net precipitation and recharge of groundwater in Riacho Fundo watershed, Felixlândia-MG

The amount of planted forests, especially those with exotic species, has increased along the last years in view of the need to supply the ever-growing demand of domestic and foreign markets for forest products. These crops are not only socially controversial but also polemic in what regards hydrological features of the local watershed. In that sense, we aimed to evaluate the net precipitation and water table level in the Riacho Fundo watershed, in Felixlândia municipality, Minas Gerais state, Southeastern Brazil, in a eucalyptus forest cover area located in the Cerrado of that state. Net precipitation was calculated by the sum of throughfall and stemflow. Water table level was monitored along four sites in the toposequence, where four piezometric wells were drilled. Net precipitation and water table level were evaluated from 2008 through 2010. Water table depth in the Riacho Fundo watershed varied with net precipitation and with the topographic position of the piezometric wells, which shows that groundwater in the eucalyptus forest area was recharged over the monitored years.

Throughfall in different forest stands of Iperó, São Paulo

In forestry, throughfall (Pi) is that fraction of rainfall that runs directly through the tree canopy and reaches the ground. It is characterized as the main source of water supply in a watershed. This study aimed to analyze the dynamics of throughfall in three types of forest stands, namely Eucalyptus cloeziana, Pinus sp. and seasonal semideciduous forest (FES), all located in Ipanema National Forest, in the municipality of Ipero-SP. In each stand, a 300 m² plot was established in which ten rain gauges were installed for monitoring throughfall, and three rain gauges were installed in an open area adjacent to the stand for measuring gross precipitation (P). At the end of 25 observations, it was observed that, relative to P values, Pi values were 76.2% in semideciduous forest (FES), 85.1% in E.cloeziana forest and 84.0% in Pinus sp forest. In addition, comparing these stands, a larger leaf canopy coverage and consequently greater capability for water retention was noted in the semideciduous forest. However, no statistical differences were observed (P<0.05) between the stands of interest regarding throughfall.

Scaling Up of Leaf Transpiration and Stomatal Conductance of Eucalyptus grandis x Eucalyptus urophylla in Response to Environmental Variables

© 2013 Tonello and Filho, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Scaling Up of Leaf Transpiration and Stomatal Conductance of Eucalyptus grandis x Eucalyptus urophylla in Response to Environmental Variables

Resistência mecânica do solo à penetração na bacia hidrográfica do Riacho Fundo, Felixlândia-MG

RESUMO – A compactacao do solo devido ao trafego de maquinas utilizadas no setor florestal causa modificacoes estruturais deste, podendo assim interferir na densidade do solo, velocidade e capacidade de infiltracao de agua e no desenvolvimento radicular das culturas. Objetivou-se, neste trabalho avaliar a resistencia mecânica do solo a penetracao na Bacia Hidrografica do Riacho Fundo, Felixlândia-MG em area de uma empresa do setor florestal localizada no cerrado mineiro. Os testes de resistencia a penetracao foram realizados em fevereiro de 2011, em seis parcelas com plantios de eucalipto localizadas nos talhoes 35, 36, 39, 40, 42 e 44, utilizando-se um penetrometro de impacto. Os talhoes apresentaram valores medios da resistencia mecânica do solo acima de 4 MPa e esses altos valores podem estar associados ao uso do solo que antes dos plantios de eucalipto era pastagem e tambem devido a condicao de baixo teor de umidade do solo no periodo em que foi realizada a determinacao da resistencia mecânica do solo.

SURFACE RUNOFF OF RAINFALL IN AN EXPERIMENTAL PLANTATION OF MACAÚBA PALM (Acrocomia aculeata) UNDER DIFFERENT FORMS OF MANAGEMENT

1 Received on 29.06.2015 accepted for publication on 25.10.2017. 2 Universidade Federal de Viçosa, Graduado em Engenharia Florestal, Viçosa, Minas Gerais Brasil. E-mail: <batistacefetrp@yahoo.com.br>. 3 Universidade Federal de Viçosa, Departamento de Engenharia Florestal, Viçosa, Minas Gerais Brasil. E-mail: <herlycarlostdias@gmail.com> and <eshamir@ufv.br>. 4 Universidade Federal de São Carlos, Departamento de Ciências Ambientais, Sorocaba, São Paulo, Brasil. E-mail: <kellytonello@yahoo.com>. 5 Instituto Florestal do Estado de São Paulo, SP Brasil. E-mail: <valdircicco@if.sp.gov.br>. 6 Universidade Federal de Viçosa, Mestre em Ciências Florestais, Viçosa, Minas Gerais Brasil. E-mail: <ljsfloresta@hotmail.com>. 7 Universidade Federal de Viçosa, Laboratório de Anatomia Vegetal, Viçosa, Minas Gerais Brasil. E-mail: <aurorasato@gmail.com>. *Corresponding author.

RAINFALL PARTITIONING IN FRAGMENTS OF CERRADO VEGETATION AT DIFFERENT STAGES OF CONDUCTION OF NATURAL REGENERATION

1 Received on 12.04.2017 accepted for publication on 07.03.2018. 2 Universidade Federal de São Carlos, Programa de Pós-Graduação em Ciências Ambientais, São Carlos, SP-Brasil. E-mail: <debora.bessi@gmail.com>. 3 Universidade Federal de Viçosa, Departamento de Engenharia Florestal, Viçosa, MG-Brasil. E-mail: <herly@ufv.br>. 4 Universidade Federal de São Carlos, Departamento de Ciências Ambientais, Sorocaba, SP-Brasil.. E-mail: <kellytonello@yahoo.com>. *Corresponding author.