Effect of flooding on survival and initial growth of Ocotea pulchella (Nees) Mez. seedlings in semi-controlled light conditions

Abstract

ABSTRACT(Eff ect of fl ooding on survival and initial growth of Ocotea pulchella (Nees) Mez. seedlings in semi-controlled light conditions). Taking into account the occurrence of Ocotea pulchella in areas subjected to periodic fl ooding, this work aimed to evaluate the survival and initial development of Ocotea pulchella seedlings (2 months old) and juveniles (9 months old) in response to waterlogging under diff erent light regimes by varying both light quantity and light quality, in order to test for possible fl ood tolerance of the species as aff ected by light conditions. Th ree levels of soil moisture (fi eld capacity, mean fl ooding -only for seedlings -and full fl ooding) and four light treatments (full sun, neutral shade, far red enriched shading and neutral plus far red) were tested. Th e survival of seedlings and juveniles during one year was relatively high, whereas growth was negatively aff ected by full sun and fl ooding. Seedling growth was inhibited by soil waterlogging whatever the light condition, whereas plant growth at fi eld capacity and mean fl ooding was similar. Flooding also inhibited the growth of juveniles, and that response was practically not aff ected by the light regimes. Th e results suggest that Ocotea pulchella seedlings can survive in the understory, even in areas subject to fl ooding, forming a slow-growth seedling bank. Th e species seems to tolerate relatively long-term soil waterlogging when kept out of direct sunlight. Otherwise, responses of waterlogged plants to shading seem to be aff ected by irradiance and light quality.

Sobrevivência e crescimento inicial de Ocotea pulchella (Lauraceae) em uma floresta de restinga da Ilha do Cardoso, SP

“…Desta forma, a hipóxia modifica o balanço de nutrientes minerais, ocasionando maior saturação por alumínio e baixo pH do solo, o que pode reduzir a absorção e transporte de íons e levar a planta a um estresse nutricional (Kozlowski et al 1991). A resposta de plantas jovens de O. pulchella à alta umidade do solo pode ser ilustrada em experimento realizado exsitu em condições semi-controladas, no qual juvenis desta espécie apresentaram redução significativa do crescimento em substrato alagado em diferentes condições de luz (Pires & Cardoso 2011).…”