Long-term plasticity in growth, storage and defense allocation produces drought-tolerant juvenile shrubs of Prosopis alpataco R.A. Philippi (Fabaceae)

VILELA, A; AGUERO, R; RAVETTA, D.A.; GONZÁLEZ-PALEO, L.

FLORA

ELSEVIER GMBH

Año: 2012 vol. 207 p. 436 - 441

0367-2530

Evaluation of phenotypic plasticity of plants is important to predict the long-term fate of populationsexposed to environmental change. Climate scenarios predict a decrease in rainfall and increase in temperaturefor Northern Patagonia (Argentina). The long-term assessment of the effect of water shortageon allocation patterns of Prosopis alpataco provides insights into how climate change could affect thisdominant shrub of the Monte Desert. A single-factor (water supply) field experiment was conducted.Phenotypic plasticity in biomass partitioning and allocation to storage and defense was assessed overthe course of pre-reproductive growth during five years. Water-effect and size-dependent effects weresorted out. Our results indicate that as plants grow larger, root:shoot ratio increases, as well as totalnon-structural carbohydrates pool, irrespective of water treatment. Increasing belowground allocationthrough partitioning to reserves instead of allocation to non-storage mass, favors carbohydrate formsthat later can be mobilized. Spine mass ratio increased 3-fold in response to drought. These conservativestrategies might facilitate the persistence of Prosopis alpataco in a novel and drier environment, throughthe production of drought-tolerant juvenile individuals.TNCSpinesBiomass allocationPlasticityAllometric trajectoryClimate change