Estrutura e distribuição espacial de populações de cactáceas nativas da caatinga no brejo e curimataú paraibano

• Ano de defesa: 2020
• Autor(a) principal: Barbosa, Fabiana dos Anjos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Agricultura; Programa de Pós-Graduação em Ciências Agrárias (Agroecologia); UFPB
• Palavras-chave em Português: Caatinga; Ecologia de Populações; Facheiro; Xique-xique; Population Ecology; CNPQ::CIENCIAS AGRARIAS
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/22754

Cacti are plants sensitive to anthropogenic disturbances because they have endemism, specific geographic distribution, very low relative growth rate and need for pollinating agents for their reproductive success. In this sense, studies on the spatial distribution of their species specimens in Caatinga areas with some degree of anthropization are necessary to support family management and conservation actions in the region. The aim of the study was to analyze the structure and spatial distribution of Pilosocereus pachycladus F. Ritter subsp. pernambucoensis (F. Ritter) and Pilosocereus gounellei (A. Weber ex K. Schum.) Bly. ex Rowl in natural populations in Brejo and Curimataú Paraibano, in the municipalities of Bananeiras and Arara and Bananeiras and Tacima, respectively. In the study areas, 25 plots of 20 m x 20 m were demarcated, totaling a sample area of 10,000 m2 (1ha). Within the plots, all individuals were labeled and the total height and circumference were measured at the base of the stem with the aid of a tape measure. The populations were described by Density (DAi), Frequency (FAi) and Absolute Dominance (DoAi) and Payandeh Aggregation Index (Pi) calculated in Mircosoft Excel 2013. The spatial distribution maps of the isolines in relation to the number of individuals per plot of the Cactaceae specimens were elaborated with the aid of SURFER® v. 8.0.In each plot, the height and diameter of each specimen at ground level (DNS) were obtained, with the aid of a graduated tubular rod and a dendrometric suture, respectively. For populations of P. pachycladus subsp. pernambucoensis 61 specimens were sampled in the vegetation of Bananeiras, presenting an absolute density of 61 ind. ha-1 and absolute frequency (FA) of 52%. 64 specimens were sampled in the Arara area, with an absolute density of 64 ind. ha-1 and absolute frequency (FA) of 56 %. The two populations were arranged in a cluster pattern (Pi = 3.74 and 3.47, respectively). P. pachycladus subsp. pernambucoensis of the two areas have a habit of aggregate growth and population structure with a reduced number of regenerating individuals. For the populations of P.gounellei, 31 specimens from the Bananeiras ecosystem were sampled, with an absolute density of 31 ind. ha-1 and absolute frequency (FA) of 52 %. 41 specimens were sampled in the Tacima forest, with an absolute density of 41 ind. ha-1 and absolute frequency (FA) of 44 %. The two populations were arranged in a cluster pattern (Pi = 4.97 and 2.35, respectively). P. pachycladus subsp. pernambucoensis of the two areas have a habit of aggregate growth and population structure with a reduced number of regenerating individuals. For the populations of P. gounellei, 31 specimens were sampled in the Caatinga of Bananeiras, with an absolute density of 31 ind. ha-1 and absolute frequency (FA) of 52 %. 41 specimens were sampled in the Caatinga of Tacima, with an absolute density of 41 ind. ha-1 and absolute frequency (FA) of 44%. The two populations were arranged in a cluster pattern (Pi = 4.97 and 2.35, respectively). P. gounellei individuals from both areas have a habit of aggregate growth and population structure with low recruitment of individuals. Regional human actions exert pressure on the recruitment rate of populations and this study points to conservationist actions of Cactaceae species to guarantee the survival of these individuals in Brejo and Curimataú Paraibano.