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

Abstract

Os tratamentos consistiram em três taxas de lotação e foram distribuídos em três piquetes: T 1 (3,1 an/ha), T 2 (1,5 an/ha) e T 3 (0 an/ha). Para análise dos dados, agruparam-se as leituras por datas nas respectivas semanas. Foi verificado efeito do pastejo sobre os parâmetros fenológicos observados, notadamente no tratamento com maior taxa de lotação, para as espécies do marmeleiro e da malva, ocasionando redução antecipada do total de folhas, flores e frutos, promovendo alteração na fenologia dessas espécies. Observou-se menor efeito do pastejo sobre a fenologia do pereiro, e não foi verificado efeito sobre a catingueira. Notou-se que os pulsos de precipitação foram suficientes para desencadear os eventos fenológicos nas espécies. A precipitação interferiu no comportamento fenológico das espécies, desencadeando o período de brotamento logo após os primeiros eventos de chuvas, bem como a floração e frutificação, acontecendo em meados do período chuvoso. A queda de folhas ocorre logo após o término do período chuvoso na catingueira, marmeleiro e malva, sendo mais persistente no pereiro.Palavras-chave: Caprinos, Semiárido e Variabilidade. PHENOLOGY OF FOUR CAATINGA SPECIES UNDER CONTINUOUS GRAZINGABSTRACT -The objective of this work was to evaluate the effect of goat grazing on the phenology of Croton sonderianus Müll. Arg., Caesalpinia pyramidalis Tull, Malva sylvestris L. and on Aspidosperma pyrifolium Mart. in a Caatinga area in the Cariri in the state of Paraíba. The experiment was carried on the experimental farm "Bacia Escola" at the Federal University of Paraíba in São João do Cariri, state of Paraíba, 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 1 Recebido

The roles of rainfall, soil properties, and species traits in flowering phenology along a savanna-seasonally dry tropical forest gradient

“…Several approaches have been used to explain seasonal variations in the reproductive phenophases of dry forest species. Parente et al (2012) reported that the most frequent species flowered only after the beginning of the rainy season. Lima et al (2012) found that species with low wood densities and greater water storage capacities flowered between the dry and rainy seasons, while high wood density species flowered only in the rainy season.…”

Temporal rainfall variability as inductor of the phenology of Brazilian semiarid species

“…The sprouting period of P. pyramidalis was occurred between March and July, varying between years, with rapid leaf emission in response to the precipitation pulses, peaked a few days after the rains. Souza et al (2014) and Parente et al (2012) identified that rainfall pulses are sufficient to trigger phenological events in this species. Thus, sprouting of P. pyramidalis can be classified as a rapid and intense precipitation-dependent event in sufficient quantity to rehydrate the plant.…”

“…Amorim et al (2009), worked with another species of the genus Aspidosperma, and reported that both sprouting and leaf fall presented a continuous pattern, with the number of leaves being reduced in relation to sprouting. Parente et al (2012) studied the same species and identified that the precipitation interfered with phenological behavior, triggering the sprouting period soon after the first rainfall events, in which A. pyrifolium was more persistent in maintaining the leaves with the prolongation of the dry season. The higher leaf persistence of A. pyrifolium individuals may be associated with the amount of nitrogen translocated to the new leaves as observed by Castro et al (2013) when studying the phenology of Aspidosperma spcies.…”

Image monitoring on the behavior study of three genetic groups of confined goats

“…Because of their adaptive characteristics to arid and semiarid conditions, native goats can survive and produce in these environments, basically consuming native vegetation that consists of arboreal and shrub species (Araújo et al, 2010;Loiola Filho et al, 2012;Parente et al, 2012).…”