Variação espacial do microclima em sistema silvipastoril com Grevillea robusta A. Cunn

Abstract

The silvipastoril system (SSP) about the interaction between animals, pastures and trees at the same time and space, and in a sustainable way. One of the main changes that occurs in this environment is in relation to microclimate generated due to the presence of trees. The present work had as objective to evaluate the different distances, in relation to the planting of trees, interfere in the microclimate in silvipastoril system with Grevillea robusta A.cunn. The research took place in the municipality of Saudade do Iguaçu-PR, in the condo Pizzolatto, which has silvipastoril system for eleven years. Monitoring of the climatic variables was carried out with the aid of a meteorological microestação with datalogger function, from May to October 2017. The weather station was positioned at 2, 10 and 18 meters in relation to the tree line. Within each distance the station was placed in the shadow and/or Sun, when necessary. The surveys were conducted three times a day, at 9, 12 and 15 hours. The design used is randomized in blocks trifactorial scheme, being three distances (2, 10 and 18 meters), two levels of shading and three times (9, 12 and 15 h). The data were subjected to analysis of variance and when significant Tukey test was carried out at 5% probability of error. The air temperature showed higher to 12 and 15 hours in places under the Sun. The global solar irradiance presented at 12 hours peak and average values were higher in sunny locations. The relative air humidity decreased throughout the day, where at 9 hours expressed percentage of 61.5%, reducing to 51% for 12 hours and 45.7% at 15 hours. Wind speed reported higher at 9 and 12 hours, with 1.4 m s-1, compared with 15 hours of 1.0 m s-1. The soil temperature during the day was 17.7° C at 9 hours, 19.1° C at 12 and 20.7° C at 15 hours. Were also observed soil temperature values smaller to 10 meters from the line of trees and in shaded spots. Soil moisture introduced interaction between distances and levels of shading, where the average values met minors 18 meters and shaded place. It can be concluded with the present work there was only spatial variation for soil-climatic variables. The shading level on silvipastoril system affected the microclimate in General, except for the speed of the wind. There is interference from the timetables of the day for variables such as temperature and relative humidity, global solar irradiance, wind speed and soil temperature. Soil moisture is modified by the presence of shadow and also because of the distance from the row of trees, less to 18 meters.