Floristics and phytophysionomies in Piratini river floodplain and their relevance to the conservation in south Brazilian Pampa

Abstract

Piratini river floodplain (PRFP) is located in coastal region of Pampa biome in southern Brazil. Recently, the PRFP was considered as a priority area for biodiversity conservation in biome, inspite of the lack of knowledge about your natural resources. The aim of this study is to survey the vascular flora, describe, quantify and identify the main native and anthropic phytophysiognomies and discuss the relevance of these to information to biodiversity conservation in a regional scale in biome. The main phytophysiognomic types were identified in aerial photographs using basic criteria of remote sensing, with checks and corrections in the field, estimated the vegetation heights based in plant life-form categories, and assessed the condition of flooding and conservation status of each vegetation type. In forest communities floristic inventory has been conducted. We defined five native and three anthropic phytophysiognomies, that were subdivided into ten different floristic subtypes. The present cover of native forests in PRFR is 4,376.83 ha, the second major remnant area in coastal Pampa. In these forests, we sampled 199 vascular plant species distributed in 146 genera and 71 botanical families, some of them classified as threatened, with restricted distribution to the region or endemic. The main phytophysiognomies of coastal Pampa were found in the PRFP. These findings corroborate the statement made by the Ministry of Environment that PRFP is an area of high priority for conservationin the biome.

Key words: floristic survey, floodplain, vascular flora, coastal plain, plant richness.