Alessandro de Paula

DECOMPOSIÇÃO DA SERAPILHEIRA FOLIAR DE FLORESTA NATIVA E PLANTIOS DE Pterogyne nitens E Eucalyptus urophylla NO SUDOESTE DA BAHIA

The decomposition process regulates the accumulation of litter and nutrient cycling in forest ecosystems, being central to its maintenance. The objective of this study was to evaluate the dynamics of leaf litter decomposition in three forest ecosystems (semideciduous forest Montana and homogeneous stands of Pterogyne nitens Tul. and Eucalyptus urophylla ST Blake), located in Vitoria da Conquista, Bahia, Brazil. To evaluate the decomposition, newly fallen leaves on the ground of trees and shrubs in each of the studied toppings were collected. The sheets were dried at 65 °C, and thereafter, 10 g portions were weighed and placed in litter bags, which were randomly distributed on the surface of the forest floor in each of the areas studied. Five litter bags at random were collected after 30, 60, 90, 120, 150 and 180 days of installation. After collection, the material contained in each litter bag was subjected to drying in an oven at 65 °C and weighed. Based on the obtained masses were estimated the percentage of the remaining mass, the rate of decomposition ( k ) and half-life time of the litter ( t 1 /2 ). For chemical characterization three subsamples were separated from the dried leaf litter, which were ground and analyzed by determination of the total nitrogen, carbon, polyphenols, lignin and cellulose. The decomposition was related to environmental variables (precipitation, temperature and humidity) and the microenvironment (temperature and soil moisture).The total accumulated litter varied significantly between the settlements studied, the highest value was observed in the area of Eucalyptus urophylla (12,7 Mg ha -1 ), followed by native forest (6,9 Mg ha -1 ) and Pterogyne nitens (1,1 Mg ha -1 ). At the end of the six months of the experiment, Eucalyptus urophylla showed the greatest remaining mass (73,6%), followed by native forest (67,8%) and Pterogyne nitens (46,3%). The decomposition constant ( k ) was higher in litter of Pterogyne nitens (0,0054 g g -1 day), with lower values for native forest (0,0016 g g -1 day) and Eucalyptus urophylla (0,0015 g g -1 day). The rate of decomposition of leaf litter of the peopling of Pterogyne nitens is in a superior position in relation to rates of native forest and stand of Eucalyptus urophylla , which provides the largest species ability to recycle organic matter and nutrients. The decomposition process in the studied ecosystems is influenced not only by the quality of the litter but also by the quality of their microenvironment.

FENOLOGIA DE Astronium graveolens Jacq. EM FLORESTA ESTACIONAL DECIDUAL EM VITÓRIA DA CONQUISTA, BAHIA

This current study had the objective to study the phenology of tree species Astronium graveolens Jacq. and correlates it with precipitation, relative humidity and temperature of the study area. The studies were conducted in a fragment of the deciduous forest in the campus of the State University of Southwest Bahia in Vitoria da Conquista, Bahia state, Brazil. The subjects were visited fortnightly from September 2010 to December 2014, when the phenological characteristics related to senescence, budding, flowering and fruiting were recorded. Data analysis done through normality tests, utilization of circular statistics to test the seasonality of phenophases and correlation test of Spearmans rank to check with which intensity and direction the climatic events were related to the phenophases. The species presented a foliar fall with deciduous pattern of high synchrony with concentration in the dry season, followed by budding highly synchronic that began in the early wet season. The flowering and fruiting presented a biennial pattern, being an event that was manifested as low sync at the asynchronous.

USO DE ESPÉCIES DA ARBORIZAÇÃO URBANA NO BIOMONITORAMENTO DE POLUIÇÃO AMBIENTAL

Biomonitoring is the use of living organisms to identify possible environmental pollution. The objective of this study was to evaluate the influence of intensity of urban traffic in the availability of elements and suspended solids as well as identify the potential in the accumulation and retention of substances in different tree species using its leaves as passive biomonitors and for accumulation. As samples we used tree leaves collected from two areas in the municipality of Vitoria da Conquista (BA state), with transit vehicles and moderate human activities, and in a zone of increased traffic and intense activities. We determined the particulate matter (MP) deposited in the leaves by the gravimetric method and the elements Fe, Cu, Ni, Co and Cd by atomic absorption spectrometry with graphite furnace (GF AAS). Fe was significantly distinguished from other variables, with higher concentrations than other metals. The data was interpreted by multivariate analysis. Cluster analysis separated two groups, one consisting of MP, Fe and Cd, because they are originated from the wear and tear of vehicles and burning fossil fuels. The species of the family Fabaceae showed greater similarity to Cu element, namely, because the Cu metabolic activity is inversely proportional to the concentration of nitrogen behavior. The vehicle traffic directly influenced the availability of some toxic elements and the concentration of the deposited solid particles. It is concluded that the species influences the accumulation of chemical elements and have different catchment potentials. The trees can be utilized as biomonitors which are passive of accumulation.

INFLUÊNCIA DOS ELEMENTOS METEOROLÓGICOS NA EVAPOTRANSPIRAÇÃO DE REFERÊNCIA ESTIMADA UTILIZANDO-SE O IRRIGÂMETRO NO MUNICÍPIO DE GUANAMBI-BA - DOI: 10.13083/1414-3984/reveng.v23n3p251-260

There are few studies on the behavior and interactions of meteorological elements on evaporation or evapotranspiration occurring in evaporimeters as the Irrigameter. Therefore, the aim of this study to analyze the effects of the interactions of weather elements, maximum temperature and minimum air, relative humidity, wind speed and solar radiation, the estimated reference evapotranspiration using the Irrigameter, operating in different heights of water level in evaporator. The study was conducted in the experimental area of the Federal Institute of Bahia, located in the municipality of Guanambi-BA. The experiment was a completely randomized design with seven treatments and three repetitions. The treatments were individually equipped with Irrigameters operating with equal water levels in the evaporators from 1 to 7cm, taken from a the reference level of the device, totaling 21 Irrigameters. To assess the direct and indirect effects of each meteorological variable on the reference evapotranspiration estimated by Irrigameter, the path analysis was used which correlates evapotranspiration, the dependent variable, with meteorological elements, the independent variables. In all water levels studied the meteorological elements that best correlated with the estimated reference evapotranspiration were relative humidity, solar radiation and wind speed, with values equal to 0.58, 0.53 and 0.49, respectively.