Response of a Woody Species from Atlantic Rain Forest, Hedyosmum Brasiliense Mart. Ex Miq. (chloranthaceae), Submitted to Water Stress Doi: 10.5007/2178-4574.2010V39p1

The studies about water status for woody plants of the Atlantic rain forest are negligence, despite its altitudinal gradient which reflect in five topographic formations with different water availability and the poor conservation status of this biome and high level of habitat fragmentation that demands a deeper scientific knowledge regarding species response to environmental heterogeneity. Seedlings of Hedyosmum brasiliense Mart. ex Miq., present at all altitudinal gradient of Atlantic rain forest were submitted to water stress and the results indicated that the species presents strategy that provides delay of tissue dissection through the adoption of mechanisms that can promote higher water absorption and retention with possibly aids its altitudinal distribution in Atlantic rain forest. These mechanisms were the increase of the root length, stomatal density, epidermis and palisade parenchyma thickness, root xylem arches; the higher distribution of carbon to root related to the shoot; the decrease of the leaf area, LAR, stomatal aperture, stomatal size, intercellular spaces and the presence of osmotic adjustment through the increase in the proline content.