Factors related to establishment of Prosopis caldenia Burk. seedlings in central rangelands of Argentina

Prosopis caldenia Burk. is one of the woody species that is increasing in abundance due to poor grazing management in the semi-arid phytogeographic region of central Argentina, commonly known as the Caldenal. The objective of this study was to evaluate the effect of herbaceous cover, cattle dung, soil disturbance, and water supply on emergence and survival of P. caldenia seedlings on sites with different grazing histories: (i) a site exposed to long-term continuous grazing by cattle (grazed site), and (ii) a long-term exclosure to domestic livestock (ungrazed site). Removal of grass cover, addition of cattle dung, and water supply enhanced seedling emergence and survival, especially in the grazed site. Results suggest that factors (direct and indirect) associated with prolonged grazing history markedly affect P. caldenia establishment. This in turn alters the grass-woody plant balance, which might reduce the potential capacity of livestock production in the Caldenal. (c) 2004 Elsevier SAS. All rights reserved.