The role of heteromyid rodents in establishment and survival of mesquite in Chihuahuan Desert black grama (<i>Bouteloua eriopoda</i>) grasslands

TitleThe role of heteromyid rodents in establishment and survival of mesquite in Chihuahuan Desert black grama (Bouteloua eriopoda) grasslands
Publication TypeConference Paper
Year of Publication2004
AuthorsDuval B.D., Killgore A., Jackson E., Whitford WG
Conference NameSixth Symposium on the Natural Resources of the Chihuahuan Desert Region
Date PublishedOctober 15, 2004
Conference LocationAlpine, TX
ARIS Log Number171297
Keywordsagents of dispersal, black grama, Chihuahuan Desert, fire, heteromyid rodents, mesquite, microsite location, small mammal activity
AbstractWe conducted experiments to examine the relative influence of fire, small mammal activity, and microsite location on the germination and survival of honey mesquite (Prosopis glandulosa) in Chihuahuan Desert black grama (Bouteloua eriopoda) grassland. Mesquite seeds were placed in simulated heteromyid rodent cache pits in unburned and burned black grama grassland and on banner-tailed kangaroo rat (Dipodomys spectabilis) burrow mounds. Germination was highest in the unburned grassland, but over-winter survival was greater in the burn microsites. A large proportion seed pits were partially excavated (between 15.6 to 21.1% of the uncaged pits and between 1.1 to 5.5% of the caged pits). However, between 0 to 50.0% of the seedlings germinated in pits that had previously been excavated. Of the seeds placed in the field in the early monsoon season, 8.0% survived over winter and 13.6% of the germinants from the post-monsoon season survived over winter. There was higher germination (13.8%) from the early monsoon experiment than in the post-monsoon experiment (3.9%). There were seasonal differences in numbers of emergent seedlings with a peak in September 2002 following late summer rains. There were no significant differences in numbers of germinants in burn and grass microsites, but there were significantly fewer germinants on banner-tailed kangaroo rat mounds. These studies suggest that heteromyid rodents may serve as agents of dispersal for honey mesquite in Chihuahuan Desert black grama grasslands.