SOLAR RADIATION VS. ATMOSPHERIC DEMAND AND THE GROWTH OF PARICÁ (Schizolobium amazonicum)

Paricá, a native species of the Amazon, is considered an excellent alternative for use in commercial forest plantations. Its wood is used for various purposes, particularly in the manufacturing of veneers and plywood. However, despite its economic importance and potential use, there are still many questions regarding the silviculture of this species. Therefore, master's student Siléia Oliveira Guimarães conducted research aimed at evaluating the ecophysiology of Paricá seedlings growing under different levels of shading and atmospheric demands, defined by air temperature (Temp) and vapor pressure deficit (dpv).

Inside climate-controlled greenhouses, Paricá seedlings grew in two environments with different atmospheric demands: low (with Temp of 20.2°C and dpv of 0.2 KPa) and high (with Temp of 25.2°C and dpv of 1.1 KPa). Within each environment, shading levels of 87%, 58%, and 0% were applied. After three months, the evaluated variables were: total dry mass, leaf mass ratio, stem mass ratio, root mass ratio, stem diameter, specific leaf area, leaf area ratio, total chlorophyll, stomatal density, and leaf blade length.

Analyzing the research results, the interaction between solar radiation regime and atmospheric demand stands out. For example, in shaded treatments, there was greater dry mass production and larger leaf area in the environment with higher atmospheric demand. However, when seedlings were grown in full sunlight, there was no significant difference between environments, despite marked differences in leaf anatomy and pigment concentration.

The research conducted by student Siléia Oliveira Guimarães contributes to understanding the relationship between environment and species, helping to clarify important points that will contribute to the successful use of the species in forest plantation projects, agroforestry systems, and the restoration of degraded areas.

Further details can be found in the complete dissertation of the student on our website.

Low demand environment: A = intense shading; B = moderate shading; C = full sun. 

High demand environment: D = intense shading; E = moderate shading; F = full sun.