The presence of the Chinese caterpillar fungus (CCF) depends on the distribution of its host insects and host plants. However, its distribution pattern in response to climate change and interspecific relationships in geographical distribution is unknown. We used the MaxEnt model to obtain areas suitable for the CCF, considering its host insects and host plants under different historical climate backgrounds. We then superimposed and analyzed them to explore the range shift in response to climate change of Chinese caterpillar fungus based on species redundancy. From the Last Glacial Maximum (LGM) to 2050, the suitable distribution pattern of the CCF is estimated to change from fragmentized to concentrated and connected. The high redundancy area (HRA) continued to increase from the Middle Holocene (MH) to the present and 2050, with an increased area of 31.46×104 km2. The suitable area moved to the northwest and the total movement distance of its average coordinates was about 500 km. The altitude of the suitable area increased continuously from the LGM to the present and to 2050, and the average altitude of HRA increased from 2740.89 m (LGM) to 4246.76 m (2050). The distribution pattern and changes of CCF under different climatic conditions provides a reference for the current and future geographical regional planning for conservation and sustainable utilization. The distribution pattern similarity of the CCF suitable area, suitable area for host insects, and host plants HRA of distribution area, might be the result of their long-term co-evolution. The decreasing trend of CCF yield under human disturbance was not as severe as expected, suggesting that climate change may be beneficial to distribution expansion of the CCF.

Saprophytic fungi play vital roles in nutrient cycling and ecosystem dynamics. However, our understanding of how saprophytic fungi interact with each other to decompose organic matter is very limited. Here, we conducted field surveys of pinecone-colonizing/decomposing mushrooms, investigated the chemical compositions of decomposing pinecones, and analyzed seven new genomes of three pairs of mushrooms in the genera Auriscalpium and Strobilurus with substrate specificities. Each pair of mushrooms successively colonizes the pinecones of a different pine species: A. orientale-S. luchuensis on Pinus yunnanensis, A. vulgare-S. stephanocystis on Pinus sylvestris, and A. microsporum-S. pachcystidiatus/S. orientalis on Pinus armandii. Our analyses revealed evidence for both competition and cooperation between Auriscalpium and Strobilurus fungi during pinecone decomposition. Their successive colonization of the two fungi groups with complementary profiles of carbohydrate-active enzymes enabled efficient decomposition and utilization of pinecones. The Auriscalpium fungi are highly effective at utilizing the recalcitrant primary organic carbons such as lignin and hemicellulose in freshly fallen pinecones. The decomposition by Auriscalpium fungi enabled the successive colonization by Strobilurus fungi which can produce an arsenal of secondary metabolites such as strobilurins to inhibit other fungi and have abundant carbohydrate-active enzymes for effective utilization of the remaining organic compounds in pinecones.