Prediction of potential distribution of three protective tree species in Xiaoxing'an mountain under different climatic scenarios

Fraxinus mandshurica, Phellodendron amurense and Tilia amurensis are the main sub top-level community building tree species in the Xiaoxing'an mountains region. The purpose of this research is to analyze the potential distribution areas of F. mandshurica, P. amurense and T. amurensis in the context of global climate change, reveal the impact of climate change on plant distribution patterns, and provide a basis for precise improvement of forest quality.

Based on 19 climate factors, soil, and altitude data, the MaxEnt model was used to predict the potential distribution of three protected tree species in the Xiaoxing'an mountains region under four climate change scenarios (ssp126, ssp245, ssp370, and ssp585): currently and in the future (2021-2040, 2041-2060, 2061-2080, and 2081-2100).

1) The MaxEnt model had a good fitting effect, with AUC values greater than 0.7; 2) The important environmental factors of F. mandshurica in sequence were the annual precipitation, the mean temperature of warmest quarter, and the precipitation of wettest month. The important environmental factors of P. amurense were the annual precipitation, the average temperature of coldest season, and the precipitation of coldest season. The important environmental factors of T. amurensis were the annual mean temperature, the mean temperature of coldest season and the annual precipitation; 3) Under the conditions of future climate change, the area of suitable habitat for F. mandshurica fluctuated significantly; Under the ssp370 climate scenario, the area of suitable growing areas for yellow pineapple decreased the most, while in other cases, the area of suitable growing areas tended to stabilize; The suitable growth area of T. amurensis ranged from 21 769.87 to 25 579.46 km², with a small range of variation and a decreasing trend. The central elevation of the core area of the three tree species increased by 85-183 m under four climate changes.

In order to improve the forest quality in the Xiaoxing'anling area, based on the principle of suitable land and trees, P. amurense can be vigorously planted in Yichun city, and purple linden can be vigorously planted in the southern part of Heihe city and the northern part of Yichun city. Climate change has a significant impact on F. mandshurica, with a small area of suitable areas and a large area of reduced levels of suitable areas. It is recommended to increase the protection of F. mandshurica.