Small mammal responses to farming practices in central Argentinian agroecosystems: the use of hierarchical occupancy models

GOMEZ, MARÍA DANIELA; GOIJMAN, ANDREA PAULA; CODA, JOSÉ A.; SERAFINI, VANESA NATALIA; PRIOTTO, JOSÉ W.

Congreso; nternational Conference of Rodent Biology and Management; 2018

Organic farming is more environmentally friendly than conventional agriculture,promoting greater levels of habitat heterogeneity. Field borders could be more suitable forbiodiversity in agricultural anthromes. Small mammals are crucial in these anthromes dueto their contribution to food webs and seed consumption. We used hierarchical multiseason occupancy models to assess the effect of organic versus conventional farming onmultiple small mammal species in agricultural anthromes of central Argentina. Wemodelled detectability and increased precision of estimates, overcoming deficiencies ofprevious studies. Small mammals were seasonally surveyed in 70 field borders(conventional) and 63 (organic) during two years. We were able to include less frequentspecialist species, detecting a positive relationship with organic management possiblybecause of higher habitat quality of borders. Vegetation volume was the most importantexplanatory variable in both managements. Species? richness was greater under organicmanagement mainly in spring when the habitat quality differences with conventionalmanagement were the greatest. Spring is key for the rodent assemblage because of thebeginning of reproductive period, when resource demand is important. We suggest thatmaintaining high quality border habitats, as those supported by organic management,could allow farmers to obtain economic profit while also contributing to biodiversityconservation. Considering the positive role that native rodents may have in someagricultural anthromes, the maintenance of high population numbers may be importantfor biodiversity conservation. The approach used in this study shows the importance ofmodelling imperfect detection, reducing bias in parameter estimates, and it should beimplemented in similar studies.