Density and cover of winter annual plants in three harvester ant habitats at the Jornada Basin LTER site, 1987

This dataset contains plant cover and density data collected in
three harvester ant (Pogonomyrmex rugosus) nesting habitats at the
Jornada Basin LTER site in 1987. The purpose of this investigation
was to answer three general questions: 1. How does the modification
of soil properties and the ratios of resources (e.g., water-N) by
ants alter species assemblages of winter annual plants at the edge
of the ant nests? 2. How does the "spring cleaning",
clipping, predation or herbivory by ants affect success of the
winter annual plants at the edge of ant nests? 3. Are there
significant differences in the floristic assemblage and belowground
standing crop (root biomass) between the edge of ant nest and the
surrounding unaffected soils? Variables included in the dataset
include density and cover of all winter annual plants measured at
regular intervals between January and May of 1987. Density is
expressed as the number of individuals of a species per square
meter. The cover of each species was calculated as the area covered
by a perpendicular (not vertical) projection of its aerial parts
onto the ground surface and expressed in covered area (cm squared)
per square meter. This study was completed in 1987.