Herly Carlos Teixeira Dias

Situação atual da mata ciliar do ribeirão São Bartolomeu em Viçosa, MG

n This study surveyed the present riparian forest along a segment of the Sao Bartolomeu watershed, ViAosa, MG, and estimated the area that should be planted with native species, using a simple and effective method for measuring small drainage systems. The segment studied showed that only 5.7% of the legally required riparian forest exists, represented by nine forest fragments in different stages of ecological succession for a total area of 3.46 hectares. In order to revegetate completely the riparian study area, a model plantation based on a species combination of different ecological groups is proposed. The area to be revegetated in order to obey current legislation is 57.24 hectares, meaning that about 82,830 seedlings of native species will need to be planted.

Precipitação efetiva em fragmento secundário da Mata Atlântica

This study was carried out in the Mata do Paraiso Experimental Training and Educational Station located in Vicosa, Minas Gerais state with the objective of estimating the net precipitation along a segment of a recently regenerated native semideciduous secondary forest, from September 2002 to May 2003. Throughfall and stemflow measurements were registered in three plots. During the study period of 5/9/02 through 7/5/03, 30 rainfall events have been monitored. Results showed values of net precipitation of 849,6 mm, throughfall of 831,7 mm, stemflow of 17,9 mm and loss interception of 189,9 mm corresponding respectively to 81,7%, 80,0%, 1,7% and 18,3% of gross precipitation value which totaled 1039,5 mm for the study period.

MORFOMETRIA DA BACIA HIDROGRÁFICA DA CACHOEIRA DAS POMBAS, GUANHÃES - MG 1

RESUMO – O objetivo deste trabalho foi estudar a morfometria da bacia hidrografica da Cachoeira das Pombas, localizada no Municipio de Guanhaes, MG. A base de dados foi disponibilizada pelo convenio SIF/CENIBRA/ UFV e consistiu dos dados matriciais Modelo Digital de Elevacao Hidrologicamente Consistente (MDEHC), rede hidrografica e direcoes de escoamento. As caracteristicas morfometricas e delimitacao da bacia e subbacias hidrograficas foram obtidas automaticamente pelo software Hidrodata 2.0. A area de drenagem encontrada foi de 6,981 km² e o perimetro de 14,864 km. De forma geral, constatou-se que a area estudada possui forma alongada, com baixa densidade de drenagem, relevo forte-ondulado e declividade media de 33,9%. Esses parâmetros possuem grande influencia sobre o escoamento superficial e, consequentemente, sobre o processo de erosao, que resulta em perda de solo, agua, materia orgânica, nutrientes e microfauna, que podem vir a provocar o assoreamento e eutrofizacao dos corpos d´agua. Quanto a orientacao do terreno, pode-se se constatar que 41% do terreno da bacia hidrografica esta exposto a face norte-oeste, e 33% de sua area total encontra-se sombreada. Para um estudo mais detalhado, procuraram-se caracterizar suas sub-bacias, onde cada uma foi analisada individualmente, concluindo-se que as cinco sub-bacias apresentam deficiencia de densidade de drenagem e forma alongada. Em termos de declividade media, os valores variaram entre 29,6 e 40,4%, representando o relevo forte-ondulado. Pode-se constatar, tambem, que a morfometria diferenciada entre as sub-bacias evidencia a necessidade de um manejo especifico de cada uma delas.

Análise hidrológica e socioambiental da bacia hidrográfica do córrego Romão dos Reis, Viçosa-MG

This study was carried out to analyze the hydrological and socioeconomic aspects in the hydrographic watershed of Romao dos Reis stream in Vicosa county, Zona da Mata region, Minas Gerais State. In this study, the land use and occupation are emphasized as determinant factors for analyzing water quality, besides physical factors. The watershed was divided into sub-watersheds enabling to choose the representative sites for data collection and analysis. Data on flow rate, water quality, relief, precipitation, landscape (top, hillside and terrace), soil type, social and economic aspects were collected. A digitalized model built from mosaics and aerial photos of the area at 1:30.000 scale was used to draw up the maps. Information on the number of residents and owners as well as their respective cropping systems and watershed occupation were obtained by applying semi-structured interviews in order to get a better understanding of the social organization and management of land use in the farms. Degradation indicators were pointed out, as well as suitable management strategies for environmental improvement that would contribute and ensure the sustainability of the watershed.

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.

Análise da qualidade das águas das precipitações em aberto e efetiva em um fragmento secundário da Mata Atlântica, no município de Viçosa, MG

The purpose of the present work was to evaluate water quality of rainfall (RF), throughfall (TF) and stemflow (SF) in a spontaneous forest ecosystem between March and October 2004. Three plots were established under the forest canopy where physical water quality analysis were carried out for throughfall and stemflow samples. Volume-weighted mean (VWM) values founded for pH, Electrical Conductivity (EC) (µS cm-1), Dissolved Solids (DS) and Turbidity (TB) were 6.55, 6.90 and 6.34; 41.57, 100.50 and 66.36; 6.09, 165 and 223.92; 1.53, 2.72 and 1.94 respectively to RF, TF and SF. Rainfall physical water quality characteristics were affected by the canopy, specially after drought periods between storms. Net throughfall and stemflow had the capacity to regularize RF pH, besides significantly increasing EC, DS and TB. The study was carried out on the Mata do Paraiso (EPTEA-MP), research station of the Universidade Federal de Vicosa (UFV) in the city of Vicosa, Minas Gerais - Brazil.

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.

Precipitação efetiva e interceptação da chuva em um fragmento florestal com diferentes estágios de regeneração

The objective of this study was to evaluate the net precipitation and the interception in a fragment of semi deciduous forest both at initial and advanced stages of regeneration in in Vicosa, Minas Gerais, from August 2009 to February 2011. Six plots were demarcated: three in the initial, and three in the advanced regeneration areas, respectively. To quantify the throughfall and the stemflow, 25 rain gauges and gatherers were installed in trees with 15 cm circumference in each plot. In addition, a rain gauge was installed in an open area to quantify the unobstructed precipitation. The gross precipitation in the period studied was of 1509.96 mm. On average, 85.08 and 74.93% of the gross precipitation, for initial and advanced stages of precipitation, respectively, reach the soil via net precipitation. The interception by the forest canopy was greater in the advanced than in the initial regeneration area, corresponding to 25.07 and 14.92% of the open area precipitation, respectively, suggesting that the more densely populated areas intercept greater rainfall, and consequently, generate less net precipitation.

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.