Effects of environmental changes on interspecific interactions of three sympatric pheasants – A study based on long-term monitoring data

Abstract

• Interactions of 3 pheasants were studied using a new model based on long-term data. • And considered habitat filtering and indirect species interactions together. • Both positive and negative interactions existed among 3 pheasants. • Species interactions varied with habitat heterogeneity and stress levels in 11 years. As the lack of a general understanding of how interspecific interactions change along varying environmental gradients exists, predicting the response of ecological communities to habitat and climate change becomes an arduous task. Researchers generally assess interspecific interactions by investigating species co-occurrence patterns. However, habitat filtering and indirect interspecific interactions can interfere with interspecific interaction signals in co-occurrence data, and these two factors have rarely been considered jointly in previous studies. By using the Markov random fields model which can control the indirect interaction, based on the 11-year co-occurrence data, we analyzed the effects of environmental factors on the interaction of three sympatric pheasant species (Chinese Bamboo Partridge Bambusicola thoracicus , Sichuan Hill Partridge Arborophila rufipectu , Temminck's Tragopan Tragopan temminckii ) in Laojunshan National Nature Reserve, China. To eliminate the interference of habitat filtering, we took the environmental change during the 11-year period as the environmental variable instead of the environmental spatial gradient commonly used in previous studies. We found that the positive interaction increased with the increase of temperature, and decreased with the increase of precipitation, and with the increase of EVI heterogeneity, the positive interaction increased and the negative interaction decreased. The results are consistent with the predictions of habitat heterogeneity hypothesis and stress gradient hypothesis. Our study provides an idea for the follow-up studies of how to eliminate the interference of habitat filtering and indirect interaction in interspecific interaction analysis.