干旱区生态环境知识资源中心

The aim was to propose a bioclimatic map of the plain of Mendoza province reflecting the climatic differences expressed by vegetation activity (foliar phenology) at regional scale. The digital image of the bioclimatic aridity index P/ETP, resulting from a previous research on time series of NDVI images, was recoded into bioclimatic classes. Each class was analysed, assessing whether factors such as soil or human activities are influencing aridity, as expressed by vegetation. Mean annual phenological rhythm was graphed for each bioclimate by reconstructing the yearly NDVI curve. Results show that humid and subhumid classes are due to irrigation. The proposed map presents five classes: subdesert (8.4%), lower arid (15.3%), upper arid (24.2%), lower semiarid (25%) and upper semiarid (27.1%). Each climatic class has a different expression of vegetation activity under natural conditions, all year long. The phenological rhythm shows that aridity reduces the contrast between minimum and maximum NDVI and that time of maximal vegetation cover varies from January, under semiarid climate, to April, in subdesert climate. This proposal allows enhancement and optimization of meteorological data throughout the whole plain by means of vegetation phenology.