Ck. Yoder et al., ROOT DISTRIBUTION PATTERNS OF COMMON CURLYMESQUITE AND SIDEOATS GRAMAON 2 TEXAS RANGELAND SITES, The Southwestern naturalist, 40(3), 1995, pp. 273-280
Root distribution was determined in terms of biomass, length and root
hairs/mm root for populations of sideoats grama (Bouteloua curtispendu
la) and common curlymesquite (Hilaria belangen) in the Edwards Plateau
and Rolling Plains resource regions of Texas. There were few signific
ant differences in incremental (100 mm increments to a depth of 1 m) o
r total root biomass or root length between species at either site. Si
deoats grama had a significantly greater root hair density than curlym
esquite from the soil surface to a depth of 600 mm at both sites. Root
hair density was greatest, for both species, at the Rolling Plains si
te. Greater root hair density of sideoats grama may be an adaptation a
llowing greater and more rapid access to water, as suggested by concur
rent studies of water use within lysimeters with sideoats grama or cur
lymesquite. This suggests that greater root hair density of sideoats g
rama confers an adaptive advantage with respect to soil water use comp
ared to curlymesquite, and may be partially responsible for its region
al dominance in advanced succession communities.