The organismic and the continuous approaches applied to phytosociological relationships in a lowland neotropical forest, Venezuela

Abstract

The Organismic and the Continuous theories are traditionally considered as antagonist in ecology studies. In this research, we make the floristic characterization of different forest communities and establish the corresponding classification, taking into account the approaches derived from the theories aforementioned. We used 1 ha plots to evaluate individuals bigger than 10 cm dbh (diameter at breast height). In each one of that plots, four sub-plots of 100 m² were measured, to study all the spermatophyta in the understory. The data obtained were considered in an Enlarged Importance Index (EII), for each species in each plot. Then, the phytosociological relationships were established, according to the importance and appearance of all the species in all the plots and the results from conglomerate and multivariate analyses. We found a great unit of vegetation where the species Pentaclethra macroloba and Carapa guianensis are characteristic-dominant. In position of summit and hillside, an Alexa imperatricis Forest was identified. A valley type exists where a Catostemma commune Forest is present, and there is another valley with a Mora excelsa Forest. We found that Organismic and Continuous approaches could be complementary to get a better understanding of the tropical forest ecosystems.

Keywords:

• Ecological classification
• importance index
• forest survey methods
• Guayana shield
• Imataca Forest Reserve