Setting Restoration Priorities For Burned Nothofagus Forests: Impacts Of Wildfire On Microsite Abundance

MATTHEW JOSEPH RUGGIRELLO; ROSINA SOLER; GIMENA BUSTAMANTE; VANESSA LENCINAS

Ginebra

Conferencia; International Association for Ecology: 13th International Congress of Ecology; 2022

International Association for Ecology

The objective of this work was to determine the impacts of wildfire on microsite type and abundance in N. pumilio-dominated forests. During the summer of 2021-2022 (December-March), we established 96, 100 m2 plots in burned and unburned (control) N. pumilio forests. Microsite type (eg., grass, bush, downed log) and abundance were recorded at 100 points per plot. Other variables measured at plot-level included distance to the unburned forest edge and cattle feces count. Leaflitter was negatively associated with distance to the unburned forest edge (r = −0.54; p < 0.001), as the percent of microsites per plot dominated by leaflitter fell from 38% in unburned plots, to 16% at 30 m, 3% at 150 m, and 1% at 270 m from the unburned forest edge. Grass-dominated microsites were positively correlated to the presence of cattle feces (r = 0.35; p < 0.001) and negatively correlated to leaflitter (r = −0.30; p=0.003). Forb cover was also negatively correlated to leaflitter (r = −0.46; p < 0.001), but not tied to cattle feces count. The combination of reduced leaflitter and increased grass and forb cover creates unfavorable conditions for N. pumilio regeneration. These adverse conditions are exacerbated in the interior of burned areas with cattle grazing. N. pumilio is unlikely to regenerate in such conditions without active restoration. A restoration experiment is underway to determine whether sowing seeds with leaflitter transported to burned areas will result in greater seed germination and seedling survival.