Variation in Tree Community Composition and Structure With Changes in Soil Properties Within a Fragment of Semideciduous Forest in South-Eastern Brazil

Abstract

The purpose of the present study was to investigate whether variations in tree community structure and soil properties were interrelated in a fragment of semideciduous forest in Martinho Campos, south-eastern Brazil. The forest was sampled by ten plots, each of which was made up of four contiguous 15×15m quadrats (total 0.9ha). Plots were randomly distributed in the fragment with the help of grid-line coordinates. Soil samples were collected from each quadrat for chemical and textural analyses, and the soil of each quadrat was classified in conformity with the US Soil Taxonomy System. All trees with diameter at the base of the stem ≥5cm were identified and measured (circumference and height). Three soil groups were recognized: Ustifluvent, Ustropept, and Dystropept. A principal component analysis independently discriminated the soil groups in terms of their chemical and textural properties, indicating the consistency of the soil classification. Significant differences among the soil groups were also found for most soil properties. Tree community physiognomy was significantly different in Ustropept soil habitat, where trees showed more pronounced slenderness. A detrended correspondence analysis indicated that tree community structure also responded to the three soil habitats. A canonical correspondence analysis, together with Spearman's rank correlations, demonstrated that species' abundance distributions were significantly correlated with the soil properties. Differences in soil nutrient content (particularly Ca2+ and K+) and in ground water regime are apparently the leading factors determining tree species distributions within the fragment.

Influência do solo e topografia sobre as variações da composição florística e estrutura da comunidade arbóreo-arbustiva de uma floresta estacional semidecidual em Ingaí, MG

“…No caso dos diâmetros, foram empregados intervalos de classe com amplitudes crescentes para compensar o forte decréscimo da densidade nas classes de tamanho maiores, típico da distribuição em J-invertido. Estes intervalos permitem uma melhor representação das classes diamétricas maiores e de baixa densidade, o que é desejável em comparações gráficas (Oliveira Filho et al 2001).…”

Contribution of Topography and Incident Solar Radiation to Variation of Soil and Plant Litter at an Area with Heterogeneous Terrain

“…Their great richness of species has repeatedly been linked to accelerated dynamics of natural processes and high availability of natural resources (Pinto et al, 2006;Homeier et al, 2010;Putten et al, 2013). A frequent approach is to use the relationships between plants and soil to evaluate the variation in richness of tropical forests, operating under the assumption that soil is a main plant resource (Chen et al, 1997;Oliveira-Filho et al, 2001;Budke et al, 2007;John et al, 2007;Gleason et al, 2010;Laurance et al, 2010;Aponte et al, 2013;Brandt et al, 2013). As such, evaluating the soil independently of plants is important to shed light on the particular processes that drive its variation and may, consequently, determine vegetation distribution in tropical forests.…”

Riqueza e estrutura do componente arbóreo e características edáficas de um gradiente de floresta ciliar em Minas Gerais, Brasil

“…As classes de distribuição de diâmetro foram definidas de forma a se ajustarem ao número de indivíduos encontrado e à amplitude da variação do diâmetro na área, conforme a seguir: Classe 1, > 5 a 10 cm; Classe 2, > 10 a 20 cm; Classe 3, > 20 a 40 cm; e Classe 4, > 40 a 80 cm. Os intervalos de classe com amplitude exponencial crescente são adotados para compensar o declínio da densidade nas classes de tamanhos maiores e típico da distribuição exponencial negativa (J-invertido), o que resulta em boa estrutura gráfica (OLIVEIRA-FILHO et al, 2001). No caso das alturas, a distribuição dos indivíduos foi baseada na altura normalmente alcançada pelas árvores, sendo definidas quatro classes: Classe 1, < 4 m; Classe 2, 4 < 8 m; Classe 3, 8 < 12 m; e Classe 4, 12 m.…”

“…Assim, a grande concentração de indivíduos nas classes inferiores de diâmetro pode ser decorrente da baixa disponibilidade de nutrientes e altos valores de umidade do solo, os quais podem restringir o desenvolvimento dos indivíduos. O formato da curva exponencial negativa apresentado pela distribuição de diâmetros é um padrão considerado comum em florestas tropicais (FELFILI et al, 1997), sendo consequência da dinâmica florestal, já que existe relação inversa entre número e tamanho (porte) dos indivíduos amostrados (OLIVEIRA et al, 2001). Schaaf et al (2006) concluíram que a distribuição diamétrica reflete as características autoecológicas das espécies.…”