Water and Nitrogen Effects on Growth and Allocation Patterns of Creosotebush in the Northern Chihuahuan Desert

Abstract

A field experiment udng 2 patterns of irrigation and 1 level of nitrogen fertilizer (10 g-N m-2) was conducted in order to discern water and nitrogen interactions that may control production of creosotebush, (Laweu tridentatu (D.C.) Cov. The 2 patterns of irrigation simulated precipitation from small, frequent events (6 mm water added weekly) or large, infrequent events (25 mm water added monthly). Understanding the factors controlling the production of this rangeland shrub may aid in the development of strategies for its management. Vegetative growth occurred mostly during March-May (spring) and August-October (summer-fall). Fruit production occurred mainly in the spring and root growth occurred mainly in the summer-fall. Irrigation increased vegetative growth and decreased fruit production. Responses to irrigation were greater during summer-fall than in the spring. Small, frequent water additions caused larger increases in vegetative plus fruit growth than did large, infrequent water additions. Nitrogen fertilization increased the growth of both vegetation and fruit in irrigated and unirrigated plots. Stem mortality and root growth were not significantly affected by irrigation or nitrogen fertilizer. Tbeae results suggest that creosotebush production is limited by both soil moisture and nitrogen availability and that temporal patterns of ralnfail may be as important as total amounts.

Emission of nitrous oxide and carbon dioxide from semi-arid tropical soils in Chiapas México

“…The N 2 emissions, as a percentage of (N 2 O+N 2 ) produced, however, were similar in the different treatments. Our data confirm the evidence that on a regional scale, aside from water availability, N availability may limit net primary N 2 O production in arid and semi-arid ecosystems (Fisher et al, 1988;Gutierrez et al, 1992). Sudden rainfall events rapidly increase the activity of soil organisms thereby stimulating N 2 O emissions (Freckman et al, 1987: Schwinning & Sala, 2004.…”

Simulating the Productivity of Desert Woody Shrubs in Southwestern Texas

“…The base temperature (TG, °C), the temperature below which development ceases, and optimum temperature (TB, °C), the temperature at which development rate and growth rate were greatest, were estimated from the observed weather data from the three weather stations. According to Fisher et al [80] (1988) and Newingham et al [81] (2012), creosotebush grows slowly in spring, while fast vegetative growth and reproductive growth occur in summer. Therefore, TB and TG for creosotebush were determined from average temperatures in spring and summer, respectively.…”

Assessing vegetation structure and ANPP dynamics in a grassland–shrubland Chihuahuan ecotone using NDVI–rainfall relationships

“…For the shrub-dominated site, summer peaks in the NDVI signal are smaller, and for particular years both spring and late-autumn peaks can exceed summer greenness. Accordingly, the timing of plant growth for Larrea tridentata (which dominates the reference shrubland site) has been shown to vary from year to year, since this species has the ability to shift the temporal patterns of vegetation growth to take advantage of changes in resource availability (Fisher et al, 1988;Reynolds et al, 1999;Weiss et al, 2004;Muldavin et al, 2008).…”

“…7b). Accordingly, field observations of ANPP for Chihuahuan landscapes found that grassland primary production is particularly coupled with monsoonal rainfall, while desert shrublands appear to be less dependent on summer precipitation (Fisher et al, 1988;Reynolds et al, 1999;Huenneke et al, 2002;Muldavin et al, 2008;Throop et al, 2012).…”