Long-Term Core Site Grasshopper Dynamics for the Sevilleta National Wildlife Refuge, New Mexico

Grasshoppers are important animals in semi-arid environments, both
as herbivores and as food resources for higher level consumer
animals. Grasshoppers tend to be numerous and speciose in semi-arid
environments, especially desert grasslands, where they range from
environmental specialists to environmental generalists. Grasshopper
populations tend to change considerably from year to year, often in
response to annual variation in rainfall and plant production. The
purpose of this study was to monitor grasshopper species composition
and abundance over large temporal and spatial dimentions which
include black grama grassland, blue grama grassland, creosotebush
shrubland, and pinyon/juniper woodland environments at the
Sevilleta, in relation to seasonal and annual variation in
precipitation and plant production. Data were collected for all
individual species to provide information on community dynamics as
well as population dynamics, starting in 1992 and continuing to the
present. The working research hypothesis for this study was that
grasshopper populations in all environments will correlate
positively to seasonal and annual variation in precipitation and
plant production. Spring grasshopper populations will be especially
high during El Nino years, and late summer populations especially
high during La Nina years.