Rainfall water quality under different forest stands

Abstract

The rainfall-forest canopy interaction can impact on the chemical and physical rain-water features and is expected that different forests will have different effects on throughfall rain-water quality parameters. This study aimed (i) to compare chemical and physical rainwater quality variables observed in both gross precipitation and throughfall measured in two different forest stands (Atlantic semideciduous forest remnant - AFR, and a Eucalyptus urograndis plantation - EUP). Each stand was monitored with 8 internal rain-gauges and one external rain-gauge, encompassing the period from March 2015 to March 2016. The results pointed out a seasonal behavior of chemical and physical rain-water variables. Gross precipitation and throughfall presented different behaviors for pH, NH3 , NH4 + and Ca hardness for AFR, and NH3 , NH4 +, Phosphate, Chloride, Ca hardness, Total Dissolved Solids and Conductivity for EUP. Besides, significant differences between the stands were found in terms of throughfall indicators for some of the rainfall events, remarkably NH3 and NH4 + which were always higher at AFR. Our findings reinforce that trees and forests promote rain water enrichment with nutrients, performing key role on environmental services such as nutrient water and air pollution mitigation.