@article {51660, title = {Effect of eliminating subterranean termites on the growth of creosotebush, Larrea tridentata}, journal = {The Southwestern Naturalist}, volume = {34}, number = {4}, year = {1989}, note = {//NMSU//LTER II//Listed in LTER3 proposal as citing LTER2 support//}, month = {1989}, pages = {549-551}, abstract = {

Soils devoid of termites are more compacted (Elkins et al., 1886), and nitrogen concentrations in the soil surface decrease with depth. This should affect the growth of deep-rooted shrubs. We studied the effects of water supplementation and termite removal on shoot growth of the common Chihuahuan Desert shrub Larrea tridentata to test the hypothesis that reduced infiltration by removal of termites would reduce growth rates of the shrub.

}, keywords = {article, articles, journal, journals, Larrea,termite effect on growth, termite, Larrea productivity, termite, removal of, water amendment, water infiltration,termite}, doi = {10.2307/3671517}, url = {files/bibliography/89-SWNat-Whitford.pdf}, author = {Julio R. Gutierrez and Walter G. Whitford} } @article {51717, title = {Effects of different patterns of supplemental water and nitrogen fertilization on productivity and composition of Chihuahuan Desert annual plants}, journal = {The American Midland Naturalist}, volume = {119}, number = {2}, year = {1988}, note = {//NMSU//LTER I//Listed in LTER2 proposal as citing LTER1 support//}, month = {1988}, pages = {336-343}, abstract = {

The effects of supplemental water supplied as large events, 25 mm per month, or as frequent small events, 6 mm per week, and available nitrogen on density, aboveground biomass and species composition of an annual plant community were studied in the northern Chihuahuan Desert. The amendments of water an N had no effect on total annual plant density. However, supplemental water resulted in increased density of eight species and nitrogen fertilization produced increased densities in nine species. Total aboveground biomass was higher in the nitrogen fertilized plots; water amendments had no effect on dry matter production and there were no significant water-nitrogen interactions. Cluster analysis showed that species composition was similar on the fertilized plots and that the plots receiving 25 mm month-1 additional water in a single event differed most from the others. Species richness was highest in the 6 mm week-2 , unfertilized plots, and lowest in the unwatered-unfertilized plots. Biomass production of six of the 23 species recorded was significantly increased by nitrogen fertilization and biomass of two species was significantly reduced.

}, keywords = {annual plant, density, annual plant,aboveground biomass, annual plant,nitrogen amendment, annual plant,species composition, annual plant,water amendment, article, articles, journal, journals, nitrogen, amendment, plant, productivity, productivity,annual plants, rainfall simulation}, doi = {10.2307/2425816 }, url = {files/bibliography/JRN00076.pdf}, author = {Julio R. Gutierrez and Da Silva, Oswaldo A. and Maria I. Pagani and Danforth Weems and Walter G. Whitford} } @article {51774, title = {Chihuahuan Desert annuals: importance of water and nitrogen}, journal = {Ecology}, volume = {68}, number = {6}, year = {1987}, note = {//NMSU//LTER I//Listed in LTER2 proposal as citing LTER1 support//}, month = {1987}, pages = {2032-2045}, abstract = {

We examined the effects of water supplementation and nitrogen amendment on biomass, cover, and density of annual plants on a termite-free and a termite-present area in the Chihuahuan Desert. Soil moisture was higher in the termite than in the termite-free plots, and in the watered than in the unwatered plots during the spring and summer. There were no differences in soil moisture among plots during the winter. Soil nitrogen was higher in the termite-free than in the termite plots. There were no differences in total plant biomass produced in termite and termite-free areas. There were significant differences in relative abundances of species among treatments. Natural rainfall was sufficient for maximum spring-annual biomass development on all plots except for the termite-free unfertilized, unwatered plots. there were the direst plots but had high soil nitrogen. Most of the herbaceous species responded to the water amendments by lengthening growing seasons, increasing density, or increasing biomass. When there was sufficient water for most of the spring annuals, high soil nitrogen levels favored increased densities and biomasses of Descurainia pinnata and Lepidium lasiocarpum. The absence of C4 summer annuals in the high-nitrogen plots suggests that relatively high soil nitrogen adversely affected the summer annuals. Termite-free watered plots had higher soil moisture than the termite-unwatered plots, but summer annuals were relatively abundant in the latter. Water amendments had a greater effect on the species abundances in the termite-free area than in the one with termites. In the area with termites, nitrogen amendments had a greater effect on species abundances. Species diversity and richness were affected by site fertility as was species composition. This study demonstrates that we must understand patterns of soil nitrogen availability and processes affecting nitrogen availability in addition to water availability, in order to understand productivity and species composition of Chihuahuan Desert annual plants.

}, keywords = {annual plant, density, annual plant, phenology, annual plant,productivity, annual plant,soil moisture, annual plant,soil nitrogen, annual plant,termite, article, articles, irrigation, also SEE , journal, journals, nitrogen, amendment, phenology,annual plant, plant community, composition, soil moisture, soil, nitrogen, termite}, doi = {10.2307/1939894}, url = {files/bibliography/JRN00052.pdf}, author = {Julio R. Gutierrez and Walter G. Whitford} } @article {51773, title = {Responses of Chihuahuan Desert herbaceous annuals to rainfall augmentation}, journal = {Journal of Arid Environments}, volume = {12}, year = {1987}, note = {//NMSU//LTER I//Listed in LTER2 proposal as citing LTER1 support//}, month = {1987}, pages = {127-139}, abstract = {

Densities and biomass of annual herbaceous plants were compared on plots receiving supplemental water of 25 mm at 4-week intervals or 6.6mm per week, and plots receiving only natural rainfall. During the first summer, there were no significant differences in total biomass between treatments, but the density and biomass of two species, Astragalus tephrodes and Euphorbia micormera, were greater on the watered plots. Several spring annuals responded to supplemental water and by late spring (April) there were decreases in biomass on the watered plots, with the greatest decreases on the 6.3 mm per week plots. Few species of summer annuals responded to supplemental water during the second year, possibly as a result of smaller rain events and/or limitation of available nitrogen. Root shoot biomass ratios were between 0.15 and 0.25 for winter-spring annuals and 0.04 and 0.03 for summer annuals.

}, keywords = {annual plant, growth response, annual plant, rainfall simulation, annual plant,soil nutrient, article, articles, Astragalus, water response, Euphorbia, water response, journal, journals, rainfall simulation, rainfall simulation,annual plant response, water,also SEE }, doi = {10.1016/S0140-1963(18)31183-2}, url = {files/bibliography/JRN00059.pdf}, author = {Julio R. Gutierrez and Walter G. Whitford} } @mastersthesis {51907, title = {Ephemeral plant responses to termites, water and nitrogen in a Chihuahuan Desert}, year = {1984}, note = {//NMSU//NONE, LTER//}, month = {1984}, pages = {102}, school = {New Mexico State University}, type = {Ph.D. Dissertationpp}, address = {Las Cruces, New Mexico}, abstract = {The effects of subterranean termites, water supplementation and nitrogen amendment on ephemeral plant biomass, cover and density were investigated in a Chihuahuan desert ecosystem. Plants were sampled on one plot of 1200 m2 previously treated with chlordane to eliminate the termites and one untreated plot (with termites). These plots were subdivided in twelve 3 x 3 m subplots. Six of these subplots were irrigated every 15 days with 13 mm H2O and the other six received only natural rainfall (unwatered plots). Three randomly selected plots in the watered and unwatered treatments in both termite and no termite plots were fertilized with 2.5 g/m2 ammonium nitrate. Soil temperature and soil moisture in the watered and unwatered plots were measured on a regular basis. Soil nitrogen and tissue nitrogen of some selected plant species growing in the different treatments were analyzed. There were no differences in soil temperature among treatments. Soil moisture was higher in the termite than in the no-termite plots, and in the watered than in the unwatered plots during spring and summer. Soil nitrogen was higher in the no-termite than in the termite plot. Long-lived plant species such as Baileya multiradiata and Eriastrum diffusum accumulated more nitrogen in the termite and watered plots than in the no-termite and unwatered plots. Short-lived species did not exhibit differences in tissue nitrogen when the different treatments were compared. Ephemeral plant species composition differed, but neither total plant biomass nor total plant cover differed between termite and no-termite plots. Most of the species responded to the water treatments either by lengthening their growing seasons, increasing their density or increasing their biomass production. In most of the cases water amendments had a greater effect on the species abundances in the no-termite than in termite plots. In the termite plots, nitrogen amendments produced the larger effects and plant response to the treatments suggests that, in the no-termite plots, the system is shifting from one dominated by water-responsive species to another dominated by nitrogen-responsive species. Termite plots were dominated by deep-rooted water-responsive species (e.g., B. multiradiata).}, keywords = {dissertation, dissertations, ephemeral plant, also SEE , ephemeral plant, nutrients, ephemeral plant, termites, nitrogen, amendment, pesticide, Chlordane, rainfall simulation, ephemeral plants, termite, Chlordane, termite,plant response, theses, thesis, water, amendment}, author = {Julio R. Gutierrez} }