| Truffle is a kind of ectomycorrhizal fungus,which grows underground and has important medicinal,food and ecological value.Due to the increasing demand for truffle in the market,unreasonable digging methods have destroyed the habitat of truffle and their symbiotic tree species.Truffle is often associated or symbiotic with pine,oak,fir and other tree species,especially Pinus armandii Franch.However,it is unclear at present what the relationship is between the distribution of P.armandii and truffle in space.Due to the many factors that affect the symbiosis between truffle and symbiotic tree species,even if it can grow mycorrhizal under natural conditions or artificial cultivation,whether it can grow fruiting bodies later depends on the temperature of the environment,rainfall,soil type,etc.Conditions and factors are complicated.The unique climate type in Yunnan Province provides good conditions for the proliferation of various truffle.Therefore,in this study,Yunnan Province was used as an example.The Max Ent model was used to predict the potential habitat of truffle.The symbiotic relationship between truffle and P.armandii was explored on a spatial scale.Analyze;at the same time predict the spatial distribution of the two in 2050 and 2070,and explore the impact of climate change on the spatial distribution of the two and the response of the symbiotic relationship to climate change.The research can provide scientific guidance for the protection and rational development and utilization of truffle and their symbiotic tree species,and at the same time provide a reference for the subsequent research on the symbiosis relationship between truffle and other specific tree species.The results show that:(1)The main environmental factors affecting truffle distribution were annual temperature range,mean temperature in the coldest season and rainfall in the driest month.(2)At this stage,the high-adapted areas of truffle in Yunnan Province are mainly concentrated at the junction of Zhaotong and Qujing,Kunming,and the Lancang River and Jinsha River basins in northwestern Yunnan.The area of high-adapted areas is 15151km2,accounting for 3.30% of the total area.The southern of Yunnan part is an unsuitable area,accounting for 76.09% of the total area.(3)At this stage,the potential symbiosis zone between truffle and P.armandii appears in the south of Diqing,Lijiang,the northeast of Dali,the northwest of Chuxiong,the northwest of Kunming,the junction of Qujing and Zhaotong,and the Baoshan area.The areas with larger distribution areas are Chuxiong and Lijiang,with an area of 36.69km2 and 30.77km2,respectively.At this stage,truffle have a significant positive correlation with P.armandii,and the areas with strong correlation are in overall agreement with the potential symbiotic areas of the two.(4)Changes in the area of the truffle suitable area in different periods: under the rcp26 scenario,the truffle suitable area shows an expansion trend from now to 2050 to 2070;under the rcp85 scenario,the suitable area decreases first and then expands Increased,but the area of suitable areas in the future is lower than the current distribution area.In the future climate change,the area of suitable truffle in the low greenhouse gas emission scenario is significantly higher than the high greenhouse gas emission scenario.Spatial changes: Under the future climate change,the truffle-adapted area as a whole will show a tendency to shift northward.The reduced habitats are mainly concentrated in the south and east,and the new habitats are characterized by decentralization.(5)Changes in the potential symbiotic area between truffle and P.armandii in different stages: At present,the area where the truffle overlap with P.armandii and suitable habitats is shrinking in the south by 2050.From 2050 to 2070,on the whole,the southern and eastern areas of the potential symbiotic zone have a tendency to shrink,but there is no obvious tendency to expand northward.The potential symbiotic zone at the junction of Nujiang,Diqing,Lijiang,and Dali is relatively stable and is not affected by emission scenarios,and they are distributed;no matter which emission scenario,the potential symbiotic zone between truffle and P.armandii from 2050 to 2070 appears Increasing trend;but the area of potential symbiosis area under the background of rcp26 concentration is significantly higher than that under the background of rcp85 concentration.At present,the spatial correlation between truffle and P.armandii is low,and the spatial correlation between the two is relatively high under future climate change. |
