Ecological restoration of degraded lands of the Monte desert: response of Prosopis trees to silvicultural practices

ALVAREZ, J.A; CONY, M.A.; VILLAGRA, P.E.

Ciudad del Cabo

Congreso; 8TH World Conference on Ecological Restoration; 2019

RES

The current degradation of desert ecosystems determines the use of management practices such as reforestation with native woody species for their ecological restoration. In addition, pruning has been suggested to optimize productivity and improve potential use for local people. Our objective was to examine the annual response to pruning by individuals planted in two degraded environments of the Monte desert: 1) individuals of Prosopis flexuosa and P. chilensis in dunes areas (DIVISADERO=DIV) (33.76S, 67.75W) and b) individuals of P. flexuosa from two different provenances planted in the rocky foothills (CRICYT=CRI) (32.89S and 68.87W). Pruning consisted in the extraction of lateral branches, leaving the main stem of 50% of the individuals. We measured the following allometric variables: equivalent basal diameter (DEQ), crown diameter, and total height. We selected 32 P. flexuosa and 32 P. chilensis trees (measurements: 2003-2012) in DIV. In CRI we selected 48 P. flexuosa trees by provenance (total N=96). Pruning was carried out at two times: the beginning of the trial and at 9 years (measurements: 2005-2017). There were no differences in height of the pruned species (DIV), nor between the different populations of P. flexuosa (CRI). We only found differences for DEQ in trees pruned at 9 years of establishment (CRI). We recorded a rapid recovery of crown diameter in pruned trees of the CRI, but not in DIV for either of the two Prosopis species. Pruning does not produce a clear increase in growth in the initial stages but it does in older trees.