Nutrient resorption from senescing leaves in two Stipa species native to central Argentina.

DISTEL, R.A., ; A.S. MORETTO ; N.G. DIDONÉ

AUSTRAL ECOLOGY

Wiley Blackwell

Año: 2003 vol. 28 p. 210 - 215

1442-9985

Nutrient resorption from senescing leaves enables plants to conserve and reuse nutrients. As such, it could be expected that plant species adapted to infertile soils have a higher nutrient resorption efciency (percentage reduction of nutrients between green and senesced leaves) and/or higher nutrient resorption prociency (absolute reduction of nutrients in senesced leaves) than those adapted to fertile soils. Our objective was to compare nitrogen (N) and phosphorous (P) resorption of two congener grasses that successfully occupy uplands of relatively low fertility (Stipa gynerioides ) or lowlands of relatively high fertility (Stipa brachychaeta ) in natural rasslands of central Argentina. The two  Stipa  species did not differ in N and P resorption efciency, but S. gynerioides  had a higher N and P resorption prociency than S. brachychaeta . As a consequence, leaf-level N and P use efciency were higher in the species adapted to low fertility conditions than in the species adapted to high fertility conditions. The higher nutrient resorption prociency of  S. gynerioides  was also associated with relatively low leaf-litter decomposition and nutrient release rates found in a previous study.