Background  Climate change and soil loss tolerance (SLT) are both among the important concerned items in the long term plan of Chinese science and technology. However, little study reports concerning the effect of climate change on soil loss tolerance is available.

Methods  We collected 3 fresh and typical purplish parent rock samples (Penglaizhen group, Shaximiao group, and Suining group) in sub-tropical region (central area of Sichuan Basin) in the beginning of 2015, then moved them to Yanting station in Sichuan of subtropical area, Yuanmou Station (Yunnan dry-hot valley, representing that climate changes into drying and warming), and to Xishuangbanna Station (Yunnan tropical rain forest, representing that climate becomes wetting and warming), respectively, and let them stand these natural climate at earth surface. We measured the soil formation rate (i.e., SLT) of the purplish rock samples by sieving in December of 2015, 2016, 2017, and 2018, respectively.

Results  There is a significant (P < 0.01) exponential function relationship between the soil formation rate of the three parent rocks and the temperature difference and rainfall, and a power function relationship between the rate and the temperature for the parent rocks of Penglaizhen group and Shaximiao group, but no obvious relationship for Suining group. Consequently, model of soil formation rate for Penglaizhen group and Shaximiao group determined by the 3 factors of air temperature, air temperature difference and rainfall, while for Suining group only by the 2 factors of air temperature difference and rainfall. Based on these models, we calculated the annual average soil formation rate of different parent rocks under different observation stations:the averaged soil formation rates of three parent rocks increased by 21.8% and 30.7% at Xishuangbanna and Yuanmou, respectively.

Conclusions  Our results documented that both wetting and warming would increase the SLT value. The SLT of the purple soil increased by 21.8% and 30.7% under the climatic background of Xishuangbanna and Yuanmou, respectively. The results of this study provide scientific basis for accurate determination of SLT in different climatic backgrounds.