Restoration of overgrazed dry Chaco forest using topsoil translocation

FERNANDA MARTÍNEZ-GÁLVEZ; MARINA ALEJANDRA DIAZ LEGUIZAMON; NICOLÁS CIMINO ; JOHANNA CROCE; FLORENCIA MINOLA; CAROLINA BEATRIZ TRIGO; ANTONIO DALMASSO ; ANDRÉS TÁLAMO

Conferencia; 9th World Conference on Ecological Restoration; 2021

Society for Ecological Restoration

In dry Chaco forest extensive grazing is practiced and the concentration of livestock around water sources produces highly degraded places. We assessed the role of soil seed bank to restore an overgrazed study area at the northwest of Argentina, but no seedling emergence was found. Thus, we evaluated the restoration of the overgrazed place using topsoil translocations combined with treatments to improve seedling emergence. Before the rainy period begins, in 0.25m2 experimental units we reintroduced 0,0125 m3 of topsoil in places with and without livestock. In addition, to increase the emergence and establishment of new individuals, we improved soil conditions (using soil scarification) and we ameliorated climate conditions (placing topsoil under nurse plants, artificial shadows, or under branches structures). After 15 months (at the end of the rainy period), 5.5 individuals/0.25m2 emerged in the best treatment (with livestock exclusion, soil scarification, and protection with nurse plants). In experimental units with livestock no emergence was found. The majority of individuals emerged were herbs, followed by woody plants, and grasses; we did not find succulent plants. We recommend to complement topsoil translocations with reintroductions of the missing life forms for a better representation of the Chaco forest. The restoration of dry Chaco forest can be achieved by using topsoil translocations after the livestock (disturbance) was removed, before the beginning of the rainy period, in places with soil and environmental conditions improved.