Features of the Daurian Pika habitats in Southwestern Transbaikalia
N. G. BORISOVA1, A. I. STARKOV1, S. V. POPOV1, M. A. ERBAJEVA2
1Institute of General and Experimental biology of SB RAS, Ulan-Ude, Russia
2Dobretsov Geological Institute of Siberian Branch of Russian Academy of Sciences, Ulan-Ude, Russia
Keywords: Ochotona dauurica, the number of burrow entrances, spatially-balanced design, relief, characteristics of the soil layer, projective vegetation coverage, generalized linear models
Abstract
Impending climate and environmental changes will require robust species distribution modeling to inform management decisions to mitigate their impacts on biodiversity. Such modeling needs the appropriate data (often including many variables) that have influenced species’ distributions over time. The Daurian Pika is a good model species for climate warming feedbacks because of its habitats climate extremes (very hot summers, very cold winters) and its key role in ecosystems of the northern Asian steppes. In this study, we quantified the predictors of pika abundance at a local scale. In 236 plots (10 × 10 m2), we measured 8 environmental variables and counted the openings of pika burrows as an index of the relative pika abundance. Generalized linear models were used to identify the dependence of the openings number on chosen environmental predictors. In the independent field study, we counted the number of pika burrow openings in the plots of the same size and used it to test the best models. The best models include percentage coverage of dense tall vegetation, slope aspect, and soil thickness as predictors. Pikas are more abundant in the plots with thick soil covered by dense, tall vegetation. Also, there are trends to set burrows on gentle slopes and plains, on grounds with slightly dense or dense and plastic soil, with low stoniness. The number of burrow openings is significantly lower on the northern and eastern slopes. Our best model predicted number of burrow openings in test plots in two localities reasonably well. Our results demonstrate that a set of abiotic factors accurately predicts the Daurian pika distribution at a local scale. We suppose that among analyzed factors, some directly relate to pikas and possibly affect their distribution in a similar way in any environment. These are soil characteristics that allow pikas to construct burrows and likely vegetation cover. Other factors mediate the impact of climate on microclimate and food resources, and their effects vary depending on local environment characteristics.
|
