Kallianna Dantas Araujo

Espécies da Caatinga como alternativa para o desenvolvimento de novos fitofármacos

Grande parte do semiarido brasileiro encontra-se em avancado processo de degradacao e poucos estudos direcionam seu desenvolvimento em consonância com essa realidade. Diante deste contexto, foi realizado um levantamento etnobotânico, a fim de subsidiar pesquisas sobre fitofarmacos ocorrentes em especies da Caatinga. Para tal, foram aplicados questionarios a 256 familias, visando a documentar o conhecimento local referente as especies arbustivo-arboreas utilizadas como medicinais pela populacao rural do municipio de Monteiro-PB. Procurou-se, por meio do levantamento floristico de um fragmento florestal, com aproximadamente 30 anos de conservacao, verificar a distribuicao das especies citadas nas entrevistas. Constataram-se 37 especies identificadas no fragmento florestal avaliado e 38 no levantamento etnobotânico, com 14 especies em comum entre os levantamentos. As especies Myracrodruon urundeuva, Sideroxylon obtusifolium, Amburana cearensis, Triplaris gardneriana, Anadenanthera colubrina, Hymenaea courbaril e Bauhinia cheilantha apresentaram-se promissoras para pesquisas voltadas a obtencao de fitofarmacos.

Influência do pastejo e da precipitação sobre a fenologia de quatro espécies em área de caatinga

The objective of this work was to evaluate the effect of goat grazing on the phenology of Croton sonderianus Mull. Arg., Caesalpinia pyramidalis Tull, Malva sylvestris L. and on Aspidosperma pyrifolium Mart. in a Caatinga area in the Cariri in the state of Paraiba. The experiment was carried on the experimental farm Bacia Escola at the Federal University of Paraiba in Sao Joao do Cariri, state of Paraiba, in 2008. Five plants per paddock were monitorated, with weekly readings, totaling 28 in from March 5th 2008 to October19th, 2008 by observing the following variables: total number of leaves, green leaves, yellow leaves, dry leaves, fruit and flowers. The treatments consisted of three stocking rates and three pastures: T1 (3.1 an/ha), T2 (1.5 an/ha) and T3 (0 an/ha). For the analysis of the data, readings were grouped by date according to their respective weeks. It was noted effects of pasture on the observed phonological parameters, especially in the treatment with the largest stocking rate, for species of quince tree and mallow causing an early reduction of the total of leaves, flowers and fruits, promoting changes in the phenology of this species. Pasture did not affect much on the phenology of pear tree and no effect was observed for catingueira. It was observed that rain pulses were sufficient to trigger phonological effects in the species. Rainfall interfered in the phenological behavior of the species, triggering the period of sprouting after the first rain, and the flowering and fruiting occurring in the middle of the rainy season. The fall of leaves occurs right after the end of rainy season for catingueira, quince and mallow, and it is more persistent for pear tree.

Cinética de evolução de dióxido de carbono em área de caatinga em São João do Cariri-PB

Because of the importance of meteorological variables in different processes that occur in the soil, the objective of this work was to evaluate the kinetics of carbon dioxide evolution (microbial activity) associated with the meteorological elements in areas in caatinga in the semiarid conditions of Paraiba. The experiment was set in the field, in the Bacia Escola/CCA/UFPB, municipality of Sao Joao do Cariri - PB. The daytime microbial activity, measured by the release of CO2 , was evaluated monthly from January to December 2008, in three adjacent areas of Caatinga corresponding to the treatments: T1 (10 animals - 1 animal/3,200 m 2 ), T2 (5 animals - 1 animal/6,400 m 2 ) and T 3 (control - no animals). The total area of the experiment was 9.6 ha and for each treatment it was used an area of 3.2 ha. Six points of collection (set at random)were selected from each treatment. The treatments were distributed in completely randomized block design arranged in sub-divided plots (3×12×6), and 3 stocking rates (Plot), 12 periods of evaluation (sub-plots) and 6 hours of evaluation (sub-subplots) and 3 blocks. The methodology was based on the principle that the CO2 released by an area of soil is absorbed by a solution of 0.5 N KOH and determined titrimetricallyc with HCl 0.1 N. The evolution of CO2 varied throughout the day in function of weather factors, mainly temperature. The rate of CO2 tended to release more in the afternoon. Due to the importance of soil and air temperatures in many processes that occur in soil, more studies are needed in the semiarid region of Brazil.