Data set ID:
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? Data set contains soil water content data measured gravimetrically at monthly intervals from January to May. Soil samples were taken from ant nest edge and from adjacent reference sites (5 m apart).
field data sheets
Soil water content from ant nest edge soil and from adjacent reference sites (5 meter apart) was measured gravimetically at monthly intervals from January to May. A 35 cm3 soil core sample was randomly taken at the edge of each ant nest, and another soil core sample of the same volume was taken at the adjacent site (5 m away) for every ant nest to 11 cm depth. Because the surface of ant nests was relatively flat and gravelly, rock particles > 2.0 mm in diameter were removed with a small brush before taking the edge soil samples. The soil core hole was refilled with adjacent soil to avoid creating a disturbance site, and rock or mineral particles were replaced.
This study was conducted at three sites on the Jornada LTER during winter-spring 1987. A burrograss-tobosa swale grassland was site 1, an area dominated by the perennial grasses Scleropogon brevifolia (burrograss) and Hilaria mutica (tobosa). This area is located 3,000 ft. (1,000 m) SE of the playa bottom or playa basin (College Playa) and subject to rare sheet flooding. A playa fringe (College Playa) was site 2, an area characterized by scattered Prosopis glandulosa (mesquite) mixed with Yucca elata and Larrea tridentata (creosotebush). The upper basin slope was site 3, an area characterized by a fairly uniform cover of Xanthocephalum sarothrae (snakeweed) and a high diversity of annual forbs and grasses. The soil series described on the watershed by Wierenga et al. (1987) from site 1 to site 3 are Dalby (Typic Torrerts, fine), Headquarter (Ustollic Haplargid, fine loamy), Bucklebar (Typic Haplargid, fine-loamy), and Dona Ana (Typic Haplargid, coarse-loamy), respectively.