Ecofisiologia de Platycyamus regnellii Benth e Cariniana estrellensis (Raddi) Kuntze submetidas à diferentes condições de sombreamento

Abstract

Platycyamus regnellii and Cariniana estrellensis are native species of Mata Atlântica with different ecological groups and genus, fairly widespread in southern of Minas Gerais of importance for the enrichment of forested areas and restoration of degraded areas. This research aimed at evaluate the physiological responses of seedlings of these two species in relation to light availability during the initial growth analyzing plants at 90 days of age were subjected to different levels of shading: full sun; 50% shading and 70% shading. During 120 days, plants were analyzed for height increment, leaf number, biomass production and physiological parameters: maximum and net photosynthetic rate, fotorespiration, apparent quantum efficiency, light compensation point and light saturation point. The experiment was conducted in a completely randomized design with 3x2 factorial analysis and subjected to analysis of variance by means of Scott-Knot test. Overall, P. reginelli and C. estrellensis had a similar response to radiation and better growth when kept in intermediate shading (50%) during the initial growth stage. The results confirm the empirical observations that classify the species P. reginelli as a pioneer and C. estrellensis as secondary species.