Relationships Between Chihuahuan Desert Perennial Grass Production and Precipitation

Abstract

Perennial grass production on the Chihuahuan Desert Rangeland Research Center in south-central New Mexico was correlated with precipitation characteristics over a 34-year period. Total December through September precipitation was highly correlated (r ¼ þ0.77, n ¼ 34) with perennial grass production. Practical generalized indices were developed that could be broadly applied by managers for predicting perennial grass production from precipitation characteristics. Perennial grass production and precipitation data on 3 separate pastures were collected over a 6-year period to evaluate the reliability of models to predict perennial grass production. Simple linear, 2-variable, quadratic, and polynomial regression models gave perennial grass production estimates that were well correlated with actual values (r ¼ þ0.85 to þ0.91, n ¼ 17) across the 3 pastures. The quadratic regression model (Y ¼ 4.04 À 0.24X þ 0.012 X 2 , X ¼ December through September precipitation, Y ¼ forage production, n ¼ 34, r ¼ 0.85) gave the most accurate predicted values. Our quadratic regression model should be of practical use to ranchers and range managers on Chihuahuan Desert upland rangelands receiving 200-300 mm annual precipitation, with loamy to sandy loam soils and in mid-to late-seral ecological condition. These conditions match those generally found on Chihuahuan Desert Uplands. We consider our quadratic regression model to be highly useful over large areas to ranchers in southern New Mexico, southeastern Arizona, southwestern Texas, and north-central Mexico. Resumen La producció n de zacates perennes en el Centro de Investigació n de Pastizales del Desierto Chihuahuense en la regió n sur-central de New Mexico se correlacionó con las características de precipitació n de un periodo de 34 añ os. La precipitació n total de Septiembre a Diciembre estuvo altamente correlacionada (r ¼ þ0.77, n ¼ 34) con la producció n de zacates perennes. Se desarrollaron índices prá cticos generalizados que pudieran ser aplicados ampliamente por los manejadores para predecir la producció n de zacates perennes a partir de las características de precipitació n. Los datos de precipitació n y producció n delos zacates perennes de tres potreros separados se colectaron en un periodo de 6 añ os para evaluar la confiabilidad delos modelos para predecir la producció n de zacates perennes. Modelos de regresió n lineal simple, de dos variables cuadrá ticos y polinomiales dieron estimaciones de la producció n de zacates perennes que estuvieron bien correlacionados con los valores actuales (r ¼ þ0.85 a þ0.91, n ¼ 17) a través de los 3 potreros. El modelo cuadrático de regresió n (Y ¼ 4.04 À 0.24X þ 0.012 X 2 , X ¼ precipitació n de Septiembre a Diciembre, Y ¼ producció n de forraje, n ¼ 34, r ¼ 0.85) dio los valores de predicció n má s certeros. Nuestro modelo de regresió n cuadrá tica debe ser de uso practico para los rancheros y manejadores de pastizales de la parte alta del Desierto Chihuahuense que reciben una precipitació n anual de 200-300 mm y con suelos de textura...

Long-Term Vegetation Trends on Grazed and Ungrazed Chihuahuan Desert Rangelands

“…Black grama, the primary decreaser forage grass in southern New Mexico, showed no difference (P . Therefore, our study was consistent with Paulsen and Ares (1962), Havstad et al (1999), Navarro et al (2002), Holechek et al (2003), and Khumalo and Holechek (2005) in showing that fluctuation in the contribution of species greatly influenced vegetation dynamics in the Chihuahuan Desert. Frequency of black grama was similar (P .…”

Anticipating changes in variability of grassland production due to increases in interannual precipitation variability

“…The relationships between precipitation and production could also be nonlinear (Khumalo andHolechek 2005, Hsu et al 2012), which might lead to disproportionate increases in ANPP variability. Nonlinear, concave-down relationships may characterize ecosystems where resources other than water limit production in wet years more than in dry years.…”

Functional Group and Species Responses to Precipitation in Three Semi-Arid Rangeland Ecosystems

“…In addition, a high correlation (r ¼ 0.88) was found between annual precipitation and forage production for 19 sites encompassing a shortgrass steppe to tallgrass prairie gradient from northeastern Colorado to eastern Kansas and Nebraska (Barrett et al, 2002). Regression relationships have been developed for predicting forage production from precipitation in many rangeland ecosystems (e.g., O'Connor et al, 2001;Khumalo and Holechek, 2005).…”