Edaphic Factors and Flooding Periodicity Determining Forest Types in a Topographic Gradient in the Northern Brazilian Amazonia

L. A. Beltrán Alemán *

Post-Graduate Program in Natural Resources, PRONAT, Federal University of Roraima, Campus Paricarana, Boa Vista, RR, Brazil.

R. I. Barbosa

Department of Environmental Dynamics, National Institute for Research in Amazonia (INPA), Rua Coronel Pinto 315, 69301-150 Boa Vista, Roraima, Brazil.

I. Montero Fernández

Postgraduate Program in Biodiversity and Biotecnology - Roraima, Federal University of Roraima, Campus Paricarana, Boa Vista, RR, Brazil.

L. C. S. Carvalho

Post-Graduate Program in Natural Resources, PRONAT, Federal University of Roraima, Campus Paricarana, Boa Vista, RR, Brazil and University of Exeter, Prince of Wales Road, Exeter, Devon, EX4 4SB, UK.

P. E. Barni

Universidade Estadual de Roraima (UERR), Campus Rorainópolis, Av. Senador Helio Campos, s/n, 69375-000 Rorainópolis, Roraima, Brazil.

R. L. C. Oliveira

Universidade Estadual de Roraima, Coordenação do Curso de Ciências Biológicas, Rua Sete de Setembro, 231, Canarinho, Boa Vista, 69306-530, Roraima, Brazil.

J. F. Vale Jr.

Departamento de Solos e Engenharia Agrícola, Universidade Federal de Roraima, Campus Cauamé, BR 174, Km 12, Bairro Monte Cristo, CEP 69300-000, Boa Vista, Roraima, Brazil.

S. A. Saravia Maldonado

National University of Agriculture, Highway to Dulce Nombre de Culmí, Neighborhood El Espino Catacamas-Olancho, Honduras.

N. E. Arriaga Pérez

National University of Agriculture, Highway to Dulce Nombre de Culmí, Neighborhood El Espino Catacamas-Olancho, Honduras.

*Author to whom correspondence should be addressed.


Abstract

The Brazilian Amazonia is a region covered by an extensive mosaic of tropical forests conditioned by different topographical and hydro-edaphic features. Although studies relating environmental determinants of structure and floristic composition are systematically evolving in the region, there is no doubt that there are still information gaps due to the lack of research in peripheric areas of the Amazonia. The seasonally flooded areas of the state of Roraima situated on rio Branco-rio Negro basin, northern Brazilian Amazonia, still are deprived of such information. In this way, this work had as objective determine the physical and soil chemical attributes, and the flooding periodicity that characterize different forest types dispersed in a topographic gradient located in an area on the north of rio Branco-rio Negro basin. Soil samples (0-60 cm) were collected along a 2.7 km transect (31.1-64.8 m a.s.l.) crossing three different forest types: (i) mosaic between treed and forested shade-loving (La+Ld), (ii) area of ecological tension between forested shade-loving and open ombrophilous forest (LO) and (iii) open ombrophilous forest (Ab+As). The results indicated different soil classes and flooding periodicity for each forest type observed: Entisols Fluvents (La+Ld, 3-4 months flooded), Entisols Quartzipsamments (LO, 1-2 months) and Yellow Ultisols (Ab+As, no flooding). All analyzed soils were defined as nutrient-poor areas, especially those located on low altitude, characterized for higher hydrological restrictions (seasonal flooding) aggregating forest types of lower structural patterns (e.g. La+Ld). Soils on low altitude were also characterized as those with the highest percentage of fine sand and silt, while soil free of seasonal flooding (Yellow Ultisols) presented the highest levels of clay and coarse sand, always associated with the ombrophilous forests (higher structural patterns). These results improve our understanding of the environmental factors conditioning different forest types in this peripheral region of Amazonia, suggesting that ecosystems with higher hydro-edaphic restrictions are a strong indicator of forest types with lower structural patterns.

Keywords: Oligotrophic ecosystems, water table, ecotone, phytophysiognomy


How to Cite

Alemán, L. A. Beltrán, R. I. Barbosa, I. Montero Fernández, L. C. S. Carvalho, P. E. Barni, R. L. C. Oliveira, J. F. Vale Jr., S. A. Saravia Maldonado, and N. E. Arriaga Pérez. 2019. “Edaphic Factors and Flooding Periodicity Determining Forest Types in a Topographic Gradient in the Northern Brazilian Amazonia”. International Journal of Plant & Soil Science 28 (6):1-11. https://doi.org/10.9734/ijpss/2019/v28i630127.