Hillside topographic pattern of tree species diversity and soil nutrients in Mount Tai, China

Forest plant diversity, soil nutrients, and hillside terrain factors are intricately linked and serve as vital indicators for assessing the overall health and biodiversity of an ecosystem. In our study, we delved into the altitudinal patterns of soil nutrients and tree diversity in Mount Tai, exploring the relationship between topographic factors and tree diversity.

We conducted field investigations along four distinct routes: Tianwaicun, Red Gate, Tianzhufeng, and Taohuayuan. Across an altitude gradient spanning from 500 to 1500 m, we established four quadrats for every 100 m of vertical ascent.

We found that: 1) the forest soil of Mount Tai has higher carbon, nitrogen and phosphorus nutrients, but with little soil potassium nutrients. 2) the forest soil nutrient pattern in Mount Tai is affected and restricted by herbaceous plants, but is less correlated with woody plants. 3) among the hillside terrain factors examined, slope position had the greatest impact on tree diversity, followed by slope direction, altitude, and gradient. 4) tree diversity exhibited a unique pattern along the altitudinal gradient, characterized by three distinct peaks and valleys.

In terms of slope patterns, moderate slopes showed the highest diversity, surpassing both steep and gently sloping areas. For slope direction, westward-facing slopes were the most diverse, while northward-facing slopes were the least. Middle slope positions demonstrated greater diversity than upper and lower positions. This study provided the basis for the healthy management of forest ecosystem in this area.