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Effect of Tree Spacing and Understory Vegetation on Water Use in a Pumice Soil
Author(s) -
Barrett James W.,
Youngberg C. T.
Publication year - 1965
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1965.03615995002900040034x
Subject(s) - understory , pumice , vegetation (pathology) , environmental science , water content , seedbed , neutron probe , hydrology (agriculture) , thinning , geology , forestry , agronomy , sowing , geography , ecology , volcano , biology , medicine , neutron cross section , physics , geotechnical engineering , pathology , canopy , neutron temperature , quantum mechanics , seismology , neutron
Water use in a pumice soil in central Oregon increased significantly with increased density of a sapling ponderosa pine ( Pinus ponderosa Laws.) stand. Study plots were thinned to 62, 125, 250, 500, and 1,000 trees/acre and replicated six times. Soil moisture measurements were begun 2 years after thinning and continued for three successive growing seasons. Soil moisture was measured with a neutron probe at three permanent stations on each plot at 3‐week intervals during the summer. Total amount of water use was 1.6 times greater on plots containing 1,000 trees/acre than on plots containing 62 trees/acre. Moisture use on plots where understory vegetation was allowed to develop normally was 45% greater than on plots where vegetation was removed. Soil in the area is a Regosol developed in dacite pumice, approximately 7,300 years old, from the eruption of Mount Mazama (Crater Lake).