Connectivity, spatial structure and the identification of priority areas for conservation of Belém area of endemism, Amazon.

Human activity has prompted a rapid decline in the forested areas of the Amazon, resulting in an increase in the number of isolated forest fragments. Belém is the smallest and most deforested area of endemism in the biome. Its high level of degradation translates into great biodiversity vulnerability and the need for urgent measures to address these changes. The aim of this research was to analyze connectivity among the Belém's remaining forest fragments and to classify them according to their importance for population dispersal. We used morphological spatial pattern analysis to characterize landscape structure and the integral index of connectivity to defi ne the importance of forest fragments. From a structural perspective, 55.28% of the forested area was classifi ed as core, 16.88% as edge. From a functional perspective, few fragments were classifi ed as highly important. In general, larger fragments were more important for connectivity. The protected areas seem to not have considered the forest connectivity in their planning, although the designation of priority areas has valued this variable. This study provides an important theoretical outline for considering connectivity in the planning phase and represents a contribution to more detailed research on how to maintain biodiversity in the Belém Area of Endemism.

Disentangling structural patterns of natural forest fragments in a savanna matrix in the eastern Brazilian Amazon / Desvendando padrões estruturais de fragmentos florestais na Amazônia Oriental

ABSTRACT Natural fragments are an important source of richness for the management and conservation of a local flora. The objective of this study was to evaluate the effect of fragmentation on the structure and composition of the plant communities of forest fragments (FF) in Alter do Chão, eastern Brazilian Amazonia. The study sample consisted of 25 FF and nine continuous forest (CF) sites. We compared plant density and species richness between site categories by t-tests, analyzed the differences in composition by cluster analysis, and assessed the effect of fragment size and distance to CF on the basal area and diameter of FF assemblages by linear regression. Individual trees and shrubs with DBH ≥1.27 cm were measured in 2x250 m plots. 17,078 individuals were recorded - 75.32% in FF and 24.68% in CF, comprising 475 species, 216 genera and 64 families. Myrtaceae and Fabaceae were the most abundant families in both FF and CF. Average species richness in FF and CF was statistically different. The 20 species with the highest importance values were similar in FF and CF. The average plant diameter was similar in FF and CF, suggesting that both are "mature" forests composed of thin individuals. Average diameter and total basal area showed a negative relationship with distance to CF and fragment area, respectively. Similarity analysis revealed two groups, one composed exclusively of portions of fragmented forest. Fragments and continuous forest differed in species composition, but were similar in structure. Diameter distribution in fragments was similar to that of primary forests.

RESUMO Fragmentos naturais constituem importante fonte de recursos para o manejo e conservação da flora local. Este trabalho avaliou o efeito da fragmentação sobre a estrutura e a composição das comunidades de plantas de fragmentos florestais (FF), em Alter do Chão, na Amazônia oriental brasileira. Foram amostrados 25 sítios em FF e nove em floresta contínua (CF). Analisamos a diferença na densidade de plantas e na riqueza de espécies entre FF e CF por teste-t, e na composição por análise de agrupamento. Utilizou-se regressão linear para avaliar o efeito do tamanho dos fragmentos e distância à CF sobre a área basal e diâmetro. Os indivíduos com DAP ≥1,27 cm foram medidos em parcelas de 2x250 m. Foram registrados 17.078 indivíduos, 75,32% nos FF e 24,68% na CF, distribuídos em 475 espécies, 216 gêneros e 64 famílias. As famílias Myrtaceae e Fabaceae foram as mais abundantes em ambos FF e CF. A riqueza média diferiu significativamente entre FF e CF. As 20 espécies com maior valor de importância foram semelhantes nos FF e CF. O diâmetro médio nos FF e CF foi semelhante, sugerindo tratar-se em ambos casos de florestas "maduras" compostas por indivíduos finos. O diâmetro médio e a área basal total mostraram relação negativa com a distância à CF e área dos fragmentos, respectivamente. A análise de similaridade revelou dois grupos, um deles composto exclusivamente por fragmentos. Composicionalmente, os fragmentos diferiram da floresta contínua, sendo estruturalmente semelhantes entre si, evidenciando distribuição diamétrica semelhante à das florestas primárias.