title: Woody encroachment and its consequences on hydrological processes in the savannah.
abstract: Woody encroachment due to changes in climate or in the disturbance regimes (fire and herbivory) has been observed throughout the savannah biome over the last century with ecological, hydrological and socioeconomic consequences. We assessed changes in tree density and basal area and estimated changes in rain interception by the canopies across a 5-year period over a biomass gradient in Cerrado vegetation protected from fire. We modelled throughfall, stemflow and net rainfall on the basis of tree basal area (TBA). Tree density increased by an average annual rate of 6.7%, basal area at 5.7% and rain interception by the canopies at 0.6% of the gross rainfall. Independent of the vegetation structure, we found a robust relationship of 0.9% less rainfall reaching the ground as TBA increases by 1 m(2) ha(-1) Increases in tree biomass with woody encroachment may potentially result in less water available for uptake by plants and to recharge rivers and groundwater reserves. Given that water is a seasonally scarce resource in all savannahs, woody encroachment may threaten the ecosystem services related to water resources.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'.
authors: Laboratório de Ecologia e Hidrologia Florestal, Instituto Florestal, Floresta Estadual de Assis, PO Box 104, 19802-970 Assis, São Paulo, Brazil Escola de Engenharia de São Carlos, Centro de Recursos Hídricos e Ecologia Aplicada, Universidade de São Paulo, PO Box 292, 13560-970 São Carlos, São Paulo, Brazil elianehonda@if.sp.gov.br.
authors: Eliane A
authors: 0000-0002-0916-5763
authors: EA
authors: Honda
authors: Laboratório de Ecologia e Hidrologia Florestal, Instituto Florestal, Floresta Estadual de Assis, PO Box 104, 19802-970 Assis, São Paulo, Brazil.
authors: Giselda
authors: 0000-0003-0693-3154
authors: G
authors: Durigan
mesh_terms: D001938:Brazil; D065928:Forests; D065948:Grassland; D062070:Hydrology; D011891:Rain; D014197:Trees / Q000254:growth & development / Q000502:physiology; D058438:Water Cycle
keywords: Cerrado; ecohydrology; fire suppression; rain interception; rain partitioning; tree biomass