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Title: Competition for water between deep- and shallow-rooted grasses

Conference · · Bulletin of the Ecological Society of America; (United States)
OSTI ID:7016908
;  [1];  [2]
  1. Washington State Univ., Pullman, WA (United States)
  2. Pacific Northwest Laboratory, Richland, WA (United States)

Competition between root systems of neighboring plants may be altered by seasonal variation in precipitation and soil moisture. Competitive effects of a deep-rooted, perennial grass, Pseudoroegneria spicata, on a shallow-rooted, perennial grass, Poa sandbergii, were monitored over two growing seasons by isolating the root system of P. sandbergii individuals within PVC tubes and comparing plant and soil characteristics to controls. When isolated for the entire growing season, P. sandbergii continued vegetative growth three weeks longer and later season soil water content was significantly greater than controls. Differences in soil water content were greatest between 30 and 50cm, below P. sandbergii's typical rooting depth. Flowering phenology was unchanged. When plants were isolated late in the season, treated plants showed more negative predown xylem pressure potential the morning after isolatron. Compared to controls, soil water content was reduced the day after tube insertion. These immediate effects on plant and soil water status may be due to removal of water supplied nightly by hydraulic lift.

DOE Contract Number:
AC06-76RL01830
OSTI ID:
7016908
Report Number(s):
CONF-940894-; CODEN: BECLAG
Journal Information:
Bulletin of the Ecological Society of America; (United States), Vol. 75:2; Conference: Annual Ecological Society of America (ESA) meeting: science and public policy, Knoxville, TN (United States), 7-11 Aug 1994; ISSN 0012-9623
Country of Publication:
United States
Language:
English