2.1. Study Area

The cultivation area of P. alba var. pyramidalis was used as a proxy study area (Figure 1). P. alba var. pyramidalis is a fine tree species for farmland shelterbelt, fast-growing and high-yield forest, windbreak and sand-fixation forest, and roadside greening because of its excellent characteristics, with strong wind resistance, drought resistance, and ease of maintenance [7]. All afforestation projects are flourishing with the long-term support and protection of the Chinese government. The host trees are widely distributed in northern China, especially in Xinjiang. To better understand the climatic environment, the distribution profile of the P. alba var. pyramidalis is as follows (Table 1) [7,26].

Occurrence records of T. klimeschi and current distribution P. alba var. pyramidalis in China.

Profile of the cultivation area of Populus alba var. pyramidalis.