Point-Quarter Distance and Dimension Measurements to Calculate Shrub Density and Estimate Shrub ANPP in a Chihuahuan Desert Creosote Shrubland at the Sevilleta National Wildlife Refuge, New Mexico

In an effort to better quantify NPP of Creosotebush in the
Five-Points region, it was decided to test the Point-Quarter method
against the standard 1-m2 quadrat method that has been in use since
1998. Transects were laid out across the 5 mammal trapping webs as
well as across burned and unburned plots of the Mixed Shrub site
(MS). Repeated measures of the same bushes are performed seasonally.
Whole shrubs of various size classes are collected, sorted, and
weighed to develop regressions for biomass. Purpose: Data was collected initially to determine density and
dimensions of creosote bush in the Five points area on core rodent
webs and on burned and unburned plots following the 2003 prescribed
burn. It was decided to expand the project by continuing
measurements through time to quantify the change in shrub size and
with simultaneous harvest of shrubs to measure NPP.