Tree Component Demography in an Upper Montane Mixed Ombrophilous Forest Under Chronic Anthropogenic Disturbances

Abstract

-The objective of this study was to understand the dynamics of an Upper Montane Mixed Ombrophilous Forest in the municipality of Painel, Santa Catarina, Brazil, where low-level but chronic disturbances, such as extensive cattle grazing and exploitation of non-timber products, are common practices. In 2008, permanent plots were allocated and all tree species with circumference at breast height (CBH) equal to or greater than 15.7 cm were measured. A second survey was conducted in 2014 by the same methodology. Mortality, recruitment, and basal area gain and loss rates were then determined. The tree species were classified into regeneration guilds and proportion tests were conducted to verify the associations between dynamics patterns and guilds. The community has shown a 2.3%.year -1 average mortality rate, a 2.2%.year -1 average recruitment rate, a 3.0%.year -1 average basal area gain rate and a 1.8%.year -1 average basal area loss rate. Species number has decreased from 55 to 48. Regeneration guilds have shown different dynamics patterns, where the pioneers have shown the greatest mortality (19.9%) and recruitment (15.6%) proportion and reduced representativeness in shade-tolerant climax species. Therefore, floristic impoverishment and higher representativeness reduction of late species have been observed. We have concluded that despite disturbances do not result in structural deterioration, they have the potential to slow the succession process and cause a floristic homogenization in the area under study. (19,9%) e recrutamento (15,6%) e com redução da representatividade do grupo de clímax tolerante à sombra. Desta forma, observou-se um empobrecimento florístico e maior redução na representatividade de espécies tardias. Conclui-se que na área de estudo, apesar das perturbações não resultarem em uma degradação estrutural, essas têm o potencial de retardar o processo de sucessão e causar uma homogeneização florística.Palavras-Chave: Floresta com Araucária; Mudança temporal; Sucessão florestal.

Dynamics of Tree Population Structure After Disturbance of Araucaria Forest Remnants

“…Therefore, the rates of change in tree communities after major disturbances are determined by a complex set of interactions between local factors, landscape structure, regional species groups, and species life histories (Chazdon et al 2007(Chazdon et al , 2016. And despite disturbances do not result in structural deterioration, they have the potential to slow the succession process in the area under study (Dallabrida et al 2017).…”

Cattle influence on the population structure of yerba mate (Ilex paraguariensis) in Araucaria Forest

“…These differences may have originated due to several factors such as microclimatic, edaphic conditions, interspecific competition, herbivory, presence of dispersers, or others such as the presence of cattle as investigated in this study. According to DALLABRIDA et al (2017), cattle presence can be considered a chronic anthropic disturbance for the PSC region, with the potential to delay the process of forest succession, influencing the composition and modifications that occur in the tree communities. The presence of cattle negatively acts on population dynamics due to their herbivorous habits, trampling and openings tracks which damage the natural regeneration of the forest (ZAMORANO-ELGUETA et al, 2012;MATTOS, 2015).…”

“…Extensive cattle can be considered a chronic anthropic disorder in the Planalto Serrano Catarinense (PSC), with the potential to delay forest succession process and cause floristic homogenization in the tree community (DALLABRIDA et al, 2017). In order to increase knowledge about I. paraguariensis ecology and conservation, we aimed to evaluate the demography and the spatial pattern of a population in AF areas in order to answer the following question: does the presence of cattle influence the populational structure of I. paraguariensis?…”

Structure and Tree Diversity in a Mixed Ombrophilous Forest Remnant, Southern Brazil

“…Despite the ecological, economic and cultural importance of MOF for the state of SC, there are still great gaps in the knowledge of its composition and structure. Some studies in floristics and phytosociology were developed for the northern plateau of state (Formento et al, 2004;Gasper et al, 2013a,b;Herrera et al 2009;Lingner et al, 2007;Negrelle & Silva, 1992) and there has recently been an important increase in such knowledge for the southern plateau of state (Dallabrida et al, 2018;Higuchi et al, 2013;Klauberg et al, 2010;Manfredi et al, 2015;Martins et al, 2012;Santos et al, 2018;Silva et al, 2016). In a review of phytosociological studies in MOF for southern Brazil, we found no studies for the western region of SC.…”