Relations among precipitation, biomass production and spectral vegetation indices: scopes and limitations

Abstract

Precipitation is one of the main factors that explain production of biomass in grassland and shrubland. Precipitation use efficiency (PUE), the ratio between biomass production and precipitation, allows the use of simple modeling paradigms (Simple Ecological Sustainability Simulator or SESS) that can be parameterized with weather information existing in the country. The PUE-Precipitation relationship is analyzed based on available experimental evidence, establishing a consistent mathematical relationship congruent with this evidence to reconsider the ratio used in the SESS model. To parameterize the PUE in function of vegetation indexes (IV), an example in Coahuila, Mexico, is analyzed of SESS model runs and NVDIcp index estimates using images from AVHRR sensor, to establish functional relationships between spectral PUE (NDVIcp/P) and the green biomass estimated with SESS model. Finally, development options for approaches to integrating models and remote sensing are discussed.