Height Structure and Spatial Pattern of Five Tropical Tree Species in Two Seasonal Semideciduous Forest Fragments With Different Conservation Histories

Abstract

-Anthropogenic disturbances in forests modify survival conditions and development of plants, which has direct effect on the height and spatial structure of tree populations. This study aimed to compare the height structure and spatial pattern of five tree species in two distinct fragments of seasonal semideciduous forest with different histories of conservation. We studied shade-intolerant (Astronium graveolens Jacq., Gallesia integrifolia (Spreng.) Harms) and shade-tolerant species (Chrysophyllum gonocarpum (Mart. & Eichler ex Miq.) Engl., Euterpe edulis Mart. and Holocalyx balansae Micheli). Sixty plots of 100 m 2 (10 m x 10 m) were allocated, being 30 contiguous plots in each fragment. All individuals of five species were marked, assessed for total height data and mapped using Cartesian coordinates. We observed differences in height structure between fragments. All populations had a random spatial pattern, except to H. balansae in the less conserved fragment and E. edulis in the conserved fragment that showed a clumped spatial pattern. There were evidences of forest regeneration due to the establishment of shade-tolerant species in less conserved fragment and coexistence of functional groups in both fragments. The height structure and spatial pattern analyses indicating that anthropogenic exploitation changed the environment and population structure in the less conserved area when compared to conserved area. The anthropic exploitation was ceased few years ago, so it is expected that the less conserved fragment reach the stability of an old-growth forest.Keywords: Size structure; Spatial pattern; Tropical forest. (10 m x 10 m), sendo 30 parcelas contíguas em cada fragmento. Todos os indivíduos, das cinco espécies, contidos nas áreas foram marcados, medidos a altura e mapeados com o uso de coordenadas cartesianas. Foram observadas diferenças na distribuição de altura, entre as áreas com diferentes históricos de conservação. Todas as populações apresentaram distribuição aleatória, com exceção de H. balansae na área menos conservada e E. edulis na área sem histórico de perturbação, que apresentaram distribuição agregada. Há indícios de regeneração florestal, devido ao estabelecimento de ESTRUTURA DE ALTURA E DISTRIBUIÇÃO ESPACIAL DE CINCO ESPÉCIES ARBÓREAS EM DOIS FRAGMENTOS DE FLORESTA ESTACIONAL SEMIDECIDUAL COM DIFERENTES HISTÓRICOS DE CONSERVAÇÃO 396Revista Árvore, Viçosa-MG, v.40, n.3, p.395-405, 2016 RODRIGUES, D.R. et al.espécies tolerantes à sombra na área menos conservada e a coexistência de grupos funcionais em ambas as áreas. A análise dos resultados da estrutura de altura e espacial demonstrou indicativos de que a exploração antrópica alterou o ambiente e a estrutura populacional das espécies da área menos conservada, quando comparado com a área mais conservada. Como não há mais exploração antrópica, espera-se que o fragmento menos conservado atinja a estabilidade de uma floresta madura.Palavras-chave: Estrutura de tamanho; Padrão espacial; Floresta tropical.

Functional Characterisation of an Anthropised Atlantic Forest Fragment

“…Shade-tolerant species tend to develop under competitive conditions in shaded environments, with increasing importance toward the maturing stages of forest succession (Tabarelli & Mantovani 1999, Chazdon 2012, Braga et al 2015. Hence, the largest percentage of shade-tolerant individuals found on sector C, unaffected by anthropisation, in relation to B, indicates that the former presents a more favorable environment for the development of such species, confirming its more advanced state of conservation (Chazdon 2012, Rodrigues et al 2016).…”

“…Sector C had lower-than-expected values for light species and higher-than-expected values for shade-tolerant species, which, considering the predominance of the latter group in conserved forests (Tabarelli & Mantovani 1999, Chazdon 2012, Corrêa et al 2014, reaffirms this sector's higher state of conservation. On the other hand, the non-significance of all other comparisons reflects the typical mixture of species found in tropical forests, which simultaneously comprise different groups representing distinct regeneration stages and dispersal syndromes (Chazdon 2012, Rodrigues et al 2016).…”

Composition of Caatinga Species Under Anthropic Disturbance and Its Correlation With Rainfall Partitioning

“…The vegetation structure can be used as an indicator of an ecosystem's conservation state. Thus, a forest inventory with multiple measurements of floristic and structural parameters is often the only way of predicting the components of vegetation changes over time (Batista et al, 2015;Rodrigues et al, 2016).…”

Population structure of understory, canopy/emergent tree species in Brazilian Atlantic Forest remnants with different Conservation status

“…The spatial structure (or spatial distribution) is an outcome of the competitive ability, colonization, and survival of populations (Maestre et al, 2008). Thus, these aspects of population structure play role as an important indicator of forest regeneration, despite not replacing the study of demography and the spatial distribution processes (Berry et al, 2008;Rodrigues et al, 2016).…”

“…Light plays a major role in plant dynamics (Tang & Dubayah, 2017;Valladares & Niinemets, 2008), particularly in areas with high heterogeneity like in selectively Logged Forests (Rodrigues et al, 2016(Rodrigues et al, , 2019. However, species may respond differently according to their characteristics, such as shade tolerance degree or forest stratum (Bianchini et al, 2010;Laurans et al, 2014;Swaine & Whitmore, 1988).…”