Caracterización florística e hidrológica de turberas de la Isla Grande de Chiloé, Chile

Abstract

Peatlands are globally known as major deposits of fresh water and carbon, affecting the planet's weather and local hydrology; for bearing unique plant and animal species, contributing to biodiversity; and because they represent a major economic resource to humanity. Peatlands are dominated by plants forming dense populations, especially Sphagnum moss and vascular plants belonging to the Cyperaceae and Juncaceae. They present high water table leveis and a deep organic matter layer (peat) below the living layer of plants. The use of fire and logging to clear forests in poor drainage soils have generated a kind of ecosystem similar to peatlands, dominated by Sphagnum moss, where peat accumulation is very low or absent (anthropogenic peatlands or "pomponales"). Compared with natural peatlands, they share the presence of Sphagnum, but they are very different in the use human beings give to them. While natural peatlands are used for peat extraction, anthropogenic peatlands are harvested for the superficial layer of living moss. The ecological consequences after both extractive activities are also different. The aim of this work is to compare the floristic composition and water table leveis between natural and anthropogenic peatlands. We sampled natural and anthropogenic peatlands with and without Sphagnum extraction. We registered 74 taxa (eight lichens, 19 bryophytes and 47 vascular plants). Differences in floristic composition allow us to distinguish between natural and anthropogenic peatlands. Water table leveis also differ between study sites, being less superficial in natural and anthropogenic peatlands without moss extraction. The hydrological alterations after peatland exploitation would bring serious ecological consequences to Chiloe island, since its only source of water comes from rainfall and is stored in these large reservoirs called peatlands.