Dendroecology of Prosopis species in the world: Secular traces of natural and anthropic events and their effects on Prosopis growth

Abstract

Prosopis genus comprises 44 species which grow in arid and semiarid environments of America, Asia and Africa and in Oceania as introduced species. Of those 44 species, 30 grow in America. Argentina is supposed to be the origin center of the genus Prosopis, and that could explain the fact that this country has the highest species variability. Prosopis species are of great ecological and social value providing goods such as firewood, food, feed for livestock and medicines as well as services acting as watershed stabilizers and nitrogen and carbon sequesters. In this chapter, we address the new insights that dendrochronological studies have provided about Prosopis genus worldwide with main emphasis in Latin America. Many studies provide information about growth dynamics which are later on applied to develop management plans, to quantify the increment in dead and alive biomass throughout time or to estimate growth changes linked to social and political events. Rainfall is the main growth driver of Prosopis throughout the Andes from Peru to central Argentina, whereas in the flat Pampas temperature is the main tree-ring width driver. Climate variables are hard to separate from other factors affecting growth such as geomorphology, anthropogenic impact and groundwater depth. Outside of Latin America, dendrochronology of Prosopis has been used for the analysis of anthropogenic contamination. Fire, the main disturbance factor in arid and semiarid environments, showed a regional dynamic as a result of human activities. Most dendroecological studies on Prosopis species, which allowed determining these species dynamics, concluded that Prosopis do not present an encroaching behavior. This review demonstrates the avant-garde and influential value of Prosopis genus for dendroecological research as it allows reconstructing past disturbances as fire, anthropogenic impact and changes in groundwater depth for the last 50–100 years and up to 356 years in the case of Prosopis caldenia Burkart in the Pampean Region.