Robberecht, R., B.E. Mahall, and P.S. Nobel. 1983. Experimental removal of intraspecific competitors - effects on water relations and productivity of a desert bunchgrass, Hilaria rigida. Oecologia 60:21-24.
Summary. Intraspecific competition in the C4
bunchgrass Hilaria rigida was examined on a Sonoran Desert
site in southeastern California. Potential competition within
monospecific stands was experimentally altered by removal of the
aboveground portions of all plants within a 1.5 m radius of a
monitored plant. Compared with unaltered plots, altered plots
had less negative soil water potentials during periods of soil
drying. Leaf blades on monitored plants of altered plots remained
green longer and had greater stomatal conductances than those
on monitored plants on unaltered plots. Production of new culms
was twice as great on altered plots. Greater root biomass and
root length were observed in altered plots, and root extension
into soil areas formally occupied by roots of neighboring plants
occurred within one year after treatment. The results indicate
that removal of the aboveground biomass of neighboring plants
reduces the competition for limited available soil water in this
desert environment.
This research was supported by United States Department of Energy
contract DE-AM03-76-SF00012.