Testing plant-herbivore and plant-plant interactions in a seasonally dry forest

JULIETA POLLICE; SILVIA ELISA NAVARRO RAMOS; ROMINA CECILIA TORRES; MARÍA LUCRECIA HERRERO; DANIEL RENISON; IGNACIO ANDRÉS IBARRA; TATIANA ALEJANDRA VALFRÉ GIORELLO

Halle, Saale, Germany

Conferencia; 30th Conference of the Plant Population Biology Section of the Ecological Society of Germany, Austria and Switzerland - GfÖ; 2017

Helmholtz Centre for Environmental Research (UFZ), the Martin Luther University Halle-Wittenberg, and the German Centre for Integrative Biodiversity Research (iDiv).

The study of plant-herbivore and plant-plant interactions has gained interest in last decades due to the influence of these interactions in the structure and composition of plant communities. Facilitation due to the protection of neighbor plants from harsh abiotic conditions is common in environments with water stress and soil degradation. Also, neighbor plants can provide protection from the negative effects of domestic herbivores. We assess if the facilitation effect depends on the N-fixing ability of neighbor plants and if the magnitude of the facilitation effect changes in grazed and ungrazed conditions. We planted 400 saplings of Kagenecka lanceolata, a native tree of Chaco Serrano region, Central Argentina, in three vegetation treatments (herbaceous, non N-fixing shrub and N-fixing shrub), in grazed and ungrazed conditions and distributed in two experimental areas that differ in their degradation state. One year after planting, sapling survival was almost 30% higher in ungrazed than in grazed condition. Survival did not differ among vegetation treatments in the most preserved area, but there was a positive effect of the two shrub types in the degraded area under both ungrazed and grazed conditions (P=0.02). Mean growth in ungrazed conditions was 17cm while in grazed conditions mean growth was negative since sapling height was lower than on plantation date (P