Long term variations in rodent abundance in a rural landscape of the Pampa, Argentina

FRASCHINA, JIMENA; LEÓN, VANINA A.; BUSCH, MARÍA

ECOLOGICAL RESEARCH

SPRINGER TOKYO

Año: 2012 vol. 27 p. 191 - 202

0912-3814

The goal of this study was to analyze the variations in 16 abundance of rodent communities along the last 24 years in a rural area, and their relation to possible changes in climatic variables and land use. The principal change in the area observed along the study period was an increase in the area covered by soybean. The habitats studied were cropfields and borders The total abundance of rodents did not show a significant trend of variation along years in cropfields while in borders the abundance in autumn-winter (A-W) showed a significant trend to decrease along years. The different rodent species showed a differential response along time. While Calomys laucha and C. musculinus showed a decrease between the period before and after the soybean expansion, Akodon azarae did not change its abundance along years. The mean minimum temperature increased over time while the numbers of days with frost decrease. Total rodent abundance in A-W was positively associated with the cumulated precipitation of the previous spring-summer period and negatively with the cumulated precipitation of the same period. We conclude that rodent abundance variations in cropfields and borders of the study area are influenced by precipitation, but the observed trends of variation along years are better explained by changes in agricultural practices than by meteorological variablesCalomys laucha and C. musculinus showed a decrease between the period before and after the soybean expansion, Akodon azarae did not change its abundance along years. The mean minimum temperature increased over time while the numbers of days with frost decrease. Total rodent abundance in A-W was positively associated with the cumulated precipitation of the previous spring-summer period and negatively with the cumulated precipitation of the same period. We conclude that rodent abundance variations in cropfields and borders of the study area are influenced by precipitation, but the observed trends of variation along years are better explained by changes in agricultural practices than by meteorological variables