Effects of nitrogen amendment on annual plants in the Chihuahuan Desert

TitleEffects of nitrogen amendment on annual plants in the Chihuahuan Desert
Publication TypeJournal Article
Year of Publication1989
AuthorsMun H.T, Whitford WG
JournalPlant and Soil
Date Published1989
Accession NumberJRN00094
Call Number00231
Keywordsannual plants,nitrogen amendment, article, articles, dominance-diversity curve, ecosystem dynamics, annual plants, fertilization, nitrogen, journal, journals, nitrogen amendment, plants, annual distribution, plants, primary production, plants, response to nitrogen, plants, species diversity, primary production, annual plants, species diversity, transect,annual plants

Effects of nitrogen amendments on spring annual plant distribution, primary production, and species diversity in a semi-arid environment were studied. The ecological responses of spring annual plant species to nitrogen differed between species, and between sites. The distribution of each species in a control transect was wider than in a nitrogen-treated transect. Annual plant species diversity at each station in the control transect was higher than that of the nitrogen-treated transect. The lower site of the Lower Basin Slope areas had the highest species diversity (0.94 for the control and 0.84 for the nitrogen-treated), and the Upper Basin Slope area, shrub vegetation zone, had the lowest species diversity (0.27 for the control and 0.05 for the nitrogen-treated) in both transects. Inorganic nitrogen in the nitrogen-treated transect soils was consistently higher than that in the control transect soils; however, the former showed more fluctuation from station to station in the latter. Above-ground biomass of spring annual plants in the nitrogen-treated transect was consistently higher than that in the control at each station. The maximum above-ground biomass in the control and nitrogen-treated transect was 24.4+-4.4 g m-2 and 61.2+-10.6 g m-2, respectively. Variations in above-ground biomass along the transect did not parallel with the variation in inorganic nitrogen in soils and species diversity.ty.