Fenologia de Cenostigma pyramidale (Tul.) Gagnon & G.P.Lewis em Sistema Ecológico de Caatinga no Cariri Ocidental Paraibano.

Abstract

Considering the importance of studies related to phenology to define the behavior of plant species and their ecosystems, the objective of this work was to evaluate the phenophases of Cenostigma pyramidale (Tul.) Gagnon & G.P.Lewis in an area of Caatinga in the semi-arid region of Paraíba. The study was carried out in the Experimental Space Reserved for Studies of Ecology and Dynamics of the Caatinga – Area I of the Ecology and Botany Laboratory – LAEB/CDSA/UFCG (7°39'38.8'' S and 36°53'42.4'' W; 538 m altitude). This space has an area of 1.05ha and 96 plots of 10 X 10m were placed in it. To monitor the phenophases of the species, we sought to identify one individual per plot, however, considering that two plots did not have the species, a total of 94 individuals were selected. Monitoring was carried out monthly from March 2019 to February 2020, recording data on budding, leaf senescence, floral bud, flowering and fruitification. Fournier intensity percentage and activity index were analyzed. In the monitoring period, the budding phenophase showed greater intensity when there was a gradual increase in precipitation. Considering the senescence phenophase, it had the highest peaks of intensity evidenced in the months October, November and December/2019, these months showing absence or reduced levels of precipitation. In the behavior of the flower bud and flowering phenophases, it was observed in the intensity that there was a synchronism between these phenophases, expressing practically the same in all monitoring months. Related to fruitification, the highest intensity occurred in April/2019, and in the same month precipitation also reached the highest value. As for the activity index for budding, between January and February 2020 all individuals expressed this phenophase. In the months of June/2019 to October/2019, the highest synchronism of the senescence phenophase was observed, in this way, it was found that 100% of the individuals expressed this activity during the beginning of the dry period. The peak of activity of the flower bud and flowering phenophases occurred in April/2019, when the highest rainfall was observed. Fruitification had the highest activity index in April/2019. Therefore, it was observed that precipitation has a great influence on phenological events, especially reproductive ones, which have greater demand for this resource.