Luciana Sanches

Seasonal Patterns of Evapotranspiration for a Vochysia divergens Forest in the Brazilian Pantanal

The recent and widespread expansion of the pioneer tree species Vochysia divergens Pohl into western Brazil has the potential to significantly alter the structure and function of the Pantanal—a UNESCO World Heritage Site and the World’s largest tropical wetland. Here we assess the seasonal pattern of evapotranspiration (ET) and micrometeorological variables of V. divergens (locally known as cambarazal), located in the Northeast of the Brazilian Pantanal. ET was calculated from a number of micrometeorological measurements recorded between January 2007 and January 2008. The results indicate that ET was the dominant sink for net radiation (Rn) during the wet and dry seasons, primarily because the forest was either flooded (December–May) or retained a high level of soil moisture. ET decreased during the dry season due to a decline in Rn and surface water availability, and an increase in atmospheric vapor pressure deficit. Based on this analysis we conclude that the spread of V. divergens into the Pantanal and the associated high rates of ET are due in part to high water availability, even during the dry season, and the consistently high leaf area index that increases the transpiration surface area when the water table is below the soil surface.

Estimativa do balanço de energia em cambarazal e pastagem no norte do Pantanal pelo método da razão de Bowen

O estudo do balanco de energia de uma superficie vegetada e a atmosfera e importante para caracterizar o microclima local, identificar interacoes entre variaveis ambientais e a vegetacao, e identificar efeitos das atividades antropogenicas. O objetivo deste trabalho foi estimar a variacao sazonal do balanco de energia pelo metodo da razao de Bowen em uma area de vegetacao monodominante de Cambara na RPPN SESC-Pantanal e uma area de pastagem na Fazenda Experimental da UFMT. Os componentes do balanco de energia apresentaram sazonalidade, com maiores medias na estacao chuvosa nas duas areas de estudo. No cambarazal houve maior variacao do fluxo de calor latente da estacao seca para a chuvosa que na pastagem. Entretanto, a variacao sazonal do fluxo de calor sensivel foi menor no cambarazal que na pastagem, devido ao efeito termo-regulador do cambarazal, em funcao da maior biomassa. A energia disponivel aos dois sitios foi destinada prioritariamente em fluxo de calor latente, 80,0% no cambarazal e 56,6% na pastagem, seguido pelo fluxo de calor sensivel, 19,1 e 42,9%, e pelo fluxo de calor no solo, 0,3 e 7,2%.

Contribuição de folhas na formação da serrapilheira e no retorno de nutrientes em floresta de transição no norte de Mato Grosso

RESUMO Este estudo foi desenvolvido numa area de floresta de transicao Amazonia-Cerrado no norte de Mato Grosso. Teve como objetivo quantificar a dinâmica da producao e acumulo e as partes constituintes da serrapilheira, bem como a participacao das folhas no retorno do nitrogenio, fosforo e carbono ao solo por meio da decomposicao. Foram coletados mensalmente durante um ano dados de serrapilheira total produzida, serrapilheira total acumulada no solo e avaliada a decomposicao de folhas no periodo de seca e de chuvas. A producao de serrapilheira apresentou variacoes sazonais com maiores valores no periodo seco e predominio da fracao foliar durante todo o ano. Por outro lado, a serrapilheira acumulada nao apresentou diferencas significativas entre o periodo de seca e o chuvoso como tambem correlacao significativa com a serrapilheira produzida. A decomposicao da serrapilheira exclusiva de folhas foi mais intensa no periodo chuvoso e em ordem decrescente de especies, em T. schomburgkii, Thyrsodium sp, B. lactescens e P. sagotianum. A especie P. sagotianum tanto no periodo seco quanto no chuvoso apresentou maior resistencia a decomposicao. O potencial de retorno de nitrogenio ao solo foi da ordem de 70,3 kg.ha -1 .ano -1 , para o fosforo, de 76,1 kg.ha -1 .ano -1 e para o carbono, de 3,5 ton.ha -1 .ano -1 . Houve uma correlacao entre a decomposicao exclusiva de folhas e o retorno de nitrogenio e fosforo para todas as especies estudadas no periodo de seca. No periodo chuvoso foi registrada correlacao significativa somente para nitrogenio e o carbono para a especie P. sagotianum. PALAVRAS-CHAVE: ciclagem de nutrientes, serrapilheira, floresta de transicao.

Efluxo de CO2 do solo em floresta de transição Amazônia Cerrado e em área de pastagem

The objective of this paper was (a) to estimate the CO2 soil efflux in a Mature Transitional Tropical Forest Amazonia and a area of Pasture in the north of the Mato Grosso; (b) to analyzer the influence of the soil humidity and temperature, and accumulated litter. The measurements had been carried through with device of CO2 absorption for infra-red ray (EGM/WMA-2 PP System, Hitchin Hertz, UK) in may/2005 to april/2006. The average values of the CO2 efflux of the ground in the Forest and the area of 5,45 and 4,94 µmolm-2s-1 Pasture µmolm-2s-1, respectively. In the dry season the behavior of the CO2 efflux of the ground was similar in the Mature Transitional Tropical Forest Amazonian and in the area of Pasture, and in the wet season the ecosystems had presented distinct behaviors, and the CO2 efflux of the ground in the area of Pasture was superior to the one in the Transitional Forest. It is essential that if it evaluates the influence of other factors in the CO2 efflux in ecosystems located in one same ecotono for the attainment of new answers that contribution to clarify doubt atmospheric CO2 emission to them the worldwide level.

Seasonal variations in litter production and its relation with MODIS vegetation indices in a semi-deciduous forest of Mato Grosso

Litter production is related to canopy processes including the timing and amount of leaf development, reproduction and net primary production. However, quantifying spatial and temporal patterns in litter production is complicated in Amazonian semi-deciduous forests because of high spatial heterogeneity and seasonal variation in rainfall. Here, we use monthly measurements of litter production and Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) composites over a 6-year period to assess whether MODIS can be used to quantify litter production of tropical semi-deciduous forests. Original MODIS NDVI and EVI values were poorly related to the seasonal periodicity in litter production, but after using singular spectrum analysis (SSA) signal extraction techniques, clear relationships between litter production and the NDVI and EVI emerged. These results indicate that MODIS NDVI and EVI data are useful for detecting temporal patterns in litter production for Amazonian semi-deciduous forests if signal extraction analyses such as SSA are conducted.

Partição do saldo de radiação em áreas de floresta amazônica e floresta de transição Amazônia - cerrado

In this work the seasonal behavior and the daily cycle of micrometeorological parameters and energy fluxes, in Amazonian forest (Rebio Jaru) and Transitional Amazonia-Cerrado forest (Maracai Farm) is analyzed. The measurements were done by equipments installed in the micrometeorological towers of LBA project (Large Scale Biosphere-Atmosphere Experiment in Amazonia), one located near from Ji-Parana city, RO (area of Amazonian forest) and other located near from Sinop city, MT (area of Transitional forest). The results analysis indicate the existence of a well defined seasonality with dry and wet seasons in both localities, which is reflected in the behavior of the precipitation, air humidity and temperature and, consequently, in the latent heat (λE) and sensible heat (H) fluxes. In the energy balance, the daily means show a different behavior of λE, in both areas, indicating more adaptation capacity of Amazonia forest to the dry period. The Rn/λE partition values showed similar seasonal behavior for both areas, with larger values for the wet season, decreasing for the dry season.

Análise de Fourier e Wavelets aplicada à temperatura do ar em diferentes tipologias de ocupação

Comumente, series temporais de temperatura do ar sao usadas nos estudos de clima devido a natureza temporal de seus sinais, que requerem investigacoes baseadas no espaco tempo-frequencia a fim de revelar caracteristicas espectrais em funcao do tempo. A transformada Wavelet fornece a representacao precisa de um sinal em funcao do tempo e da frequencia, simultaneamente, alem de permitir analisar qualquer tipo de sinal ao qual a Serie de Fourier se limita em determinadas analises. Desta forma, o presente trabalho fez uma analise da serie temporal da temperatura do ar utilizando a serie de Fourier e a transformada de Wavelet em quatro pontos, tres de area urbana e um de area rural, em 2007. A intensidade de energia na alta escala de frequencia para a temperatura do ar foi 24 h verificando-se potencias significativas no decorrer do ano todo, nas escalas temporais de 2 a 32 dias, para os quatro pontos de estudo cuja variância mais acentuada foi no centro da area urbana.

BENEFÍCIOS DA ARBORIZAÇÃO EM PRAÇAS URBANAS - O CASO DE CUIABÁ/MT

The urban forestry contributes directly to the quality of life in cities, benefiting their physical-environmental. Examining the case of two public squares in Cuiaba, Brazil, this study investigated how trees affect the conditions of the microclimate in urban areas. This study aimed to assess the variables that contribute the thermal environment of squares Popular and April 8 and how this influences the use by people analyzing the relationships among the factors involved in this process, mainly through the woody vegetation. This involved measurements of leaf area index (LAI), rates of shading and tree density (ISA and IDA), size and identification of various species. Also, we performed measurements of meteorological variables for 15 continuous days on a rainy dry season and another in 2009. Held parallel to one behavioral assessment verification of the dynamics of use by people. It was observed that the mean air temperature below the canopy was reduced by 0.45 ° C and 0.30 ° C respectively in dry and rainy seasons. By multivariate analysis using clusters of vegetation characteristics, the results indicated dichotomy resulting in a number of areas with high leaf area index and large trees, and another group with less leaf area index, tree size and percentage of shaded area. It was concluded that it is important to add efforts to qualify the environment through public squares better planning and proper methodology in selecting tree species to be adopted.

Macro-nutrientes no lençol freático em Floresta Intacta, Floresta de Manejo e Pastagem no norte de Mato Grosso

Forest removal for other land uses has been a constant in the north of Mato Grosso and can alter the hydrological and biochemical cycles. In this context, the present work aims to identify the variation of phosphorus and nitrogen in the water sheet in areas of Mature Forest, Management Forest and Pasture in the north of Mato Grosso. The water level was measured monthly and water samples for analysis were collected monthly from January/2005 to November/2006. We verified the precipitation and the air temperature seasonality, and in the dry season the quality of the water sheet presented greater values of total phosphorus and total Kjeldhal nitrogen in the studied areas. The phosphorus and nitrogen presented greater values in forest ecosystems (Forest and Management Forest) as indicative of the function of the vegetal covering in the nutrient cycle.

Fuzzy Logic System Modeling Soybean Rust Monocyclic Process

The soybean rust (Phakopsora pachyrhizi H. Sydow & P. Sydow) was reported in soybean (Glycine max L. Merrill) in many tropical and subtropical regions, causing significant reductions in productivity and quality of seeds (Bromfield, 1984, Hartman et al., 2005; Kawuki et al., 2004; McGee, 1992, Medina et al., 2006, Sinclair & Backman, 1989; Vale, 1985, Yang et al., 1990, Yang et al., 1991; Yorinori & Lazzarotto, 2004), with losses of up to 70% in production (Bromfield, 1976). The rust occurs in almost all soybean fields in Brazil. The states with high occurrence of the disease in 2003/04 were Mato Grosso, Goias, Minas Gerais and Sao Paulo. Considering Brazilian states in 2002/03, soybean rust caused losses of 4.011 million of megagrams or the equivalent of US