Light environment influences the flood tolerance in Cordia americana (L.) Gottschling & J.S.Mill.

Abstract

The subtropical riverine forests present a variation in soil water availability throughout the year, following precipitation seasonality. The objective of this work was to evaluate the responses of Cordia americana to different light intensities combined with soil flooding. Seedlings were acclimated to light treatments, with full sun and shade conditions. Sun and shade plants were subjected to soil flooding during periods of 10 (short) and 30 (longer) days. After 10 days, flooded plants had a higher root dry mass accumulation and soluble sugars content, regardless of the light condition. Shade plants presented higher shoot soluble sugars content in relation to the sun plants. After 30 days, a higher shoot soluble sugar content was observed in sun and shade flooded plants. In addition, a higher root soluble sugar content was also observed in sun plants under flood. Periods of short flooding, characterized in subtropical forests as from 5 to 15 days, favor the growth of shade plants and the roots sugar accumulation, fact that can explain the species distribution. However, long periods of flooding may be associated with light environment plasticity, suggesting that the sun plants present a higher flooding tolerance, directly associated with the ability to maintain the sugar content.

Respostas morfológicas ao alagamento em espécies arbóreas de florestas ribeirinhas subtropicais brasileiras

“…A abscisão foliar e a redução do crescimento da raiz merecem destaque, sugerindo um efeito direto da redução da difusão de gases nos processos metabólicos da parte aérea e raiz. Já a estratégia de I. vera e E. involucrata para tolerar períodos de alagamento parece envolver mecanismos de ajustes bioquímicos para manutenção do crescimento (Bender et al 2017, Samojeden et al 2018.…”