Semi Arid Land Surface-Atmosphere Project. (SALSA)
An overview of changing surface processes in semiarid grasslands of the San Pedro catchment near Cananea- Sonora, Mexico.
Analisis de los Procesos de Evolucion de las Superficies (suelo-vegetacion) en region semiarida, Rio San Pedro - Sonora, Mexico.
REPORT of the CAMPAIGN 1996-1997
INFORME de ACTIVIDAD 1996-1997.
Monteny B.A.* Lopez Morales J.P.* Elguero E.1 and Lhomme J.P.*
* ORSTOM-DICTUS : Universidad de Sonora, A.P.1819, Hermosillo-SONORA
1 ORSTOM-IMADES : Institudo del Medio Ambiente y del Desarrollo
Sustentable en el Estado de Sonora, Hermosillo - SON.
December 1997
A. Contentido
1. OBJETIVO
2. METAS
3. RESUMENB. Contents
1. INTRODUCTION
2. CHARACTERISTICS OF THE CATCHMENT AREA
2.1. Catchment area and Sites description
2.2. Northeastern Sonora climate
2.3. Vegetation and soil3. EXPERIMENTAL METHODS
3.1. Regional climate - Weather station near Morelos
3.2. Radiation budget
3.3. Available energy (Rn - G)
3.4. Precipitation / soil moisture availability
3.5. Small scale variability
3.6. Soil-vegetation-atmosphere interaction4. PRELIMINARY RESULTS AND INTERPRETATION
4.1. Morelos site climatic characteristics
4.2. Precipitation / soil moisture availability
4.3. Vegetation : areal biomass production
4.4. Radiation budget over sparse vegetation
4.5. Available energy (Rn - G)
4.6. Soil-vegetation-atmosphere interaction: fluxes measurements
4.7. Scale variability
Summary
The results of our study on ecosystem processes in the mountain plateau region of northeastern Sonora (Mexico) suggest that some climatic parameters such as rainfall characteristics, combined with long-term grazing of semiarid grasslands, prompt an increase in the spatiotemporal heterogeneity of water, vegetation and other soil resources. Soil water distributions throughout the area affect the soil surface properties (soil surface temperature, wind erosion), thus promoting the development of more adapted plants and inducing a negative effect on the growth phase in grassland ecosystems. The effects of these processes (desertization/desertification) on productive grassland have modified the general aspect of the catchment landscape. The general trend is an increase in bare areas in some parts, invasion of other types of grasses (annual), bushes and cacti, thus modifying the physiognomy of the landscape.
This study report highlights the overall trends based on nearly 1 year of weather parameters measurements, with emphasis on the summer intensive observation period involving microclimatic measurements on different types of grassland in the semiarid environment of northeastern Sonora.
Our aim is to inform Salsa project participants on the results of our 1996-1997 field study at the San Pedro catchment site (Mexico). The methods used to understand the different processes are presented along with some preliminary data.
homepage