Growth of Schizolobium amazonicum (Huber ex Ducke) under different conditions of shading and atmospheric demand
Name: SILÉIA OLIVEIRA GUIMARÃES
Publication date: 22/10/2015
Advisor:
Name |
Role |
|---|---|
| JOSÉ EDUARDO MACEDO PEZZOPANE | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| JOSÉ EDUARDO MACEDO PEZZOPANE | Advisor * |
| PAULO CEZAR CAVATTE | External Examiner * |
Summary: GUIMARÃES, Siléia Oliveira. Growth of Schizolobium amazonicum (Huber ex Ducke) under different conditions of shading and atmospheric demand. 2015. Dissertation (Master of Forest Science) - Federal University of Espirito Santo, Jerônimo Monteiro, ES. Advisor: Profº. Dr. José Eduardo Macedo Pezzopane.
The paricá (Schizolobium amazonicum Huber ex Ducke) presents itself as an excellent alternative for use in plantations of pure forest stands, agroforestry and land reclamation projects. The wood is used for various purposes, principally in manufacturing blades and plywood. However, despite its economic importance and potential use, the species still needs to be studied in silvicultural terms. Therefore, this study aimed to evaluate the morphological, physiological, anatomical and adaptive responses of Shizolobium amazonicum seedlings due to different levels of atmospheric demands and shading. The experiment was conducted in two environments of different atmospheric demands (low and high) with vessels arranged on three metal benches (3.0 x 1.2 x 1.0 m in length, width and height, respectively). In each environment, two benches had two different levels of shading (heavy and moderate using 1.5 m high black nylon screen structures), and one bench had no shade at all (full sun), thus providing 3 different levels of photosynthetically active radiation. We employed a completely randomized design (CRD) with 6 treatments in a 2x3 factorial with six replications and two levels of atmospheric demand and 3 levels of solar radiation, with a total of 36 plants. After being subjected to treatments for 94 days, seedling growth was characterized by measurements of morphological, physiological and anatomic variables and by the phenotypic plasticity index. Mean variables were subjected to analysis of variance and then compared by the Tukey test (P ≤ 0.05). Analyses were performed using the statistical program Assistat 7.7 beta. In the species studied, shading exerted greater influence on most of the variables analyzed (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 length of leaf surface), however, the atmospheric demand was a limiting factor for the variables of height, internode length, total leaf area and unit leaf area. According to the observed data of total dry matter and the phenotypic plasticity index, the species showed preference for the environment of high atmospheric demand (average temperature of 25.2 ° C and average vapor pressure deficit (VPD) of 1.1 kPa) in moderate shading and full sun conditions. This response approximately reflects the prevalent conditions of the center of origin of this species, which covers the regions of the Tropical Amazon Rainforest and the Tropical Semideciduous Forest. Still though, in environments of low atmospheric demand, the condition of full sun favored the production of total dry mass. In this way, the seedlings of the species Shizolobium amazonicum may be indicated for use in reforestation projects, land reclamation and agroforestry systems under full sun conditions in both high or low atmospheric demand environments or moderate shade (58%) conditions in high atmospheric demand environments.
Keywords: anatomy, acclimation, ecophysiology, morphology, paricá, temperature, water vapor pressure deficit
