2011 Fiscal Year Final Research Report

Evapotranspiration at a secondary forest and a bare land in Central Amazonia

Research Project

Project/Area Number	21500999
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Geography
Research Institution	Hiroshima University
Principal Investigator	TSUCHIYA Akio 広島大学, 大学院・総合科学研究科, 助教 (00263632)
Project Period (FY)	2009 – 2011
Keywords	アマゾン / 再生林 / 天然林 / 牧場 / 蒸散 / 蒸発 / 土壌水分 / 水収支
Research Abstract	Micro-meteorological and stem sap flow measurements were repeated five times from 2009 to 2011 at a primary forest, a secondary forest, and a pasture in central Amazonia. The evapotranspiration was estimated to be 8. 1-17. 2 t/ ha/ day for the secondary forest, and that for the primary forest was 10. 9-24. 3 t/ ha/ day, respectively. The daily evaporation at the pasture was calculated to be 8. 2-28. 7 t/ ha, and that of precipitation was 16. 1-112. 7 t/ ha. When the pasture was covered with grass, the evaporation was larger than the evapotranspiration at forests, while when the livestock had eaten the grass, the evaporation fell below the evapotranspiration. In the latter case, temperatures increased near the ground surface and the air-filled porosity expanded with the progress of evaporation. The cancellation of grazing expansion policies and conversion to secondary forests will be important steps to stopping the drying and warming of Amazonia.

(2 results)