Phenology of some herbaceous and woody species in central, semiarid Argentina

Abstract

Phenological stages of several grasses, shrubs, trees and herbaceous dicots are described at a site typical of rangelands in the Monte Phytogeographical Province (Argentina). High soil water levels determined an extension of tillering during su=er in the autumn-winter-spring perennial grasses, and during latespring and su=er in the spring-su=er perennial grasses. This cautions about strictly classifying these grasses as either cool-or warm-season species. Stem elongation, flowering, fructification and/or seed dispersal in several perennial grasses, and the boot stage, flowering and/or the reproductive stage in some woody species occurred earlier in dryer than in wet springs. However, reproductive phenological phases in other perennial grass and woody species were either advanced or extended later into the season as years became wetter. During wet su=ers, sprouting can extend even until early autumn in the woody species. The temporal plasticity in the phenology of grasses, herbaceous dicots or woody species suggests they are well adapted to the great intra - and interannual variation in rainfall which can occur in the region under study.