Geomorphological-related heterogeneity as reflected in tree growth and its relationships with climate of Monte Desert Prosopis flexuosa DC woodlands

S. PIRAINO; ABRAHAM, E.; DIBLASI, ANGELA; ROIG, FIDEL

TREES-STRUCTURE AND FUNCTION

SPRINGER

Lugar: Berlin; Año: 2015

0931-1890

Desert forests grow under diverse ecological conditions, mainly resulting from the spatial heterogeneity of drylands with consequences on tree growth and its interactions with climate. In the Monte Desert, geomorphological processes generate landform and soil variability, determining the distribution and growth of plant species. Prosopis flexuosa DC., a dominant tree species in the Central Monte Desert, grows in territories characterized by a high variability of landform and soil. We applied classical dendrochronological and statistical analysis to disentangle the effect of spatial heterogeneity upon the species radial growth and its further relation with precipitation fluctuations. Trees from 11 plots distributed in seven P. flexuosa forests encompassing the most important geomorphological/landform units in the Central Monte Desert were analyzed. Tree-ring development at both high and low frequencies reflects spatial landform variability. Soil heterogeneity drives ring growth within landform. Regionally, precipitation influences radial growth at the beginning and the end of the growing season, while locally dependent mechanisms related to landform/soil variability emerged. In this sense, the negative influence of latesummer precipitation found for a riparian chronology is a function of soil permeability. Ring growth at the paleoriver environment depends on late spring and early midsummer precipitation, with within-landform differences probably related to soil heterogeneity. In the case of interdune and lowland units, radial growth depends on early spring rainfall. Our findings highlight the influence of the heterogeneity of desert environments on tree growth. The information is relevant to management and conservation policies, particularly for the forests of P. flexuosa in Argentine Monte.