Can dryland use modify the assemblage of animals removing Prosopis flexuosa (Fabaceae) seeds?

CLAUDIA M. CAMPOS; MIGUEL F.; MÓNICA I. CONA

Simposio; 6th International Symposium- Workshop on Frugivores and Seed.; 2015

The fruits of Prosopis flexuosa are indehiscent pods, with a mesocarp rich in sugars and proteinand palatable to dispersing animals. The aim of this study is to analyse the role of seed removersat sites with different land uses (protected area with grazing exclusion -Ñacuñán Reserve-,protected area with domestic animals included -Ischigualasto Park-, and unprotected area undercontinuous grazing pressure -adjacent to Ñacuñán Reserve-). Fruit removal field trials areconducted using camera traps (Moultrie M-990i). At each site, we offer 20 pods (250 seeds) under20 trees for 48h. The main results allow identifying and quantifying seed removal by animals thatdisperse seeds by endozoochory (native species: Lycalopex griseus, Dolichotis patagonum, Rheaamericana, Lama guanicoe; exotic species: Lepus europaeus, cow, horse, donkey) and scatter-hoarding (Microcavia asutralis), and animals that predate seeds (Graomys griseoflavus). In theprotected area without livestock and in the unprotected area, the main species removing seeds areG. griseoflavus (41.75±1.4; mean ± SE), L. griseus (13.12±0.9), and M. australis (11.4± 00.9). Inthe protected area with domestic animals, endozoochorous mammals are the most importantdispersers: donkey, L. griseus, cow, horse, and D. patagonum. This is the first study assessing theextent of P. flexuosa seed removal by different animals in drylands under different land useconditions. In the long term, grazing exclusion produces changes in habitat structure and adecrease in the abundance of some dispersers, such as D. patagonum and M. australis, promotingseed removal by sigmodontine rodents that mainly act as seed predators.