Effects of variable retention forest management on richness and abundance of plants, insects and birds in Nothofagus pumilio forests

SCHINDLER, S; SOLER, R; LENCINAS, MV; MARTÍNEZ PASTUR, G; PERI, P

Congreso; IUFRO World Congress; 2015

Variable retentionharvesting should maintain postharvest continuity of structural andcompositional diversity. Here, we test the performance of variable retention inconserving biodiversity by synthesizing results from long-term field trials ina meta-analysis. We compared the effect of aggregated (AR) and dispersedretention (DR) on primary forests conditions (PF), including 517 study casesfor Nothofagus pumilio forests inTierra del Fuego (Argentina).The effect sizes were calculated by Z-transformation in random-effect modelswith categorical data. Richness and abundance of native plants were higher inAR and DR than in PF, with the exception of a lower abundance in DR. Exoticplants were particularly rich and abundant in DR. Insects were hardly affectedby the treatments, whereas birds richness and abundance were higher in AR andDR than in PF. Forest species maintained their populations in AR, but not inDR; temporal trends showed a fast increase of plant species richness and acontinuous increase of plant abundance. Due to the considerable increase ofexotic species in DR, we conclude that variable retention has significantecological impact on the original forest characteristics. However, at least inAR, plants, insects and birds of  N. pumilio forests, were maintained inseemingly stable populations.