Abstract:

To provide theoretical evidence for ecological recovery and protection on wild fruit forest, the relationship between plant community species diversity and soil factors under different intensities of grazing disturbance were explored in wild fruit forest of western Tianshan Mountain. Taking the undergrowth plants in the wild fruit forest as research object, according to the division method of grazing intensity and the typical plot method, 12 typical herbal samples were arranged. Using the plant species important value, species diversity and soil factor as the evaluation indexes, mild type (2-3 km from the herdsmen’s settlement), moderate type (1-2 km from the herdsmen’s settlement), and severe type (0-1 km from the herdsmen’s settlement) were compared to study the change of community structure, species diversity and soil factors. The relationship between plant community species diversity and soil factors was analyzed. The results showed that with the increase of grazing intensity, the plant composition of the community changed significantly, the plant community dominant species Cynodon dactylon and Trifolium spp. were gradually replaced by Taraxacum mongolicum. The species diversity of understory plant communities showed a gradual decline, the soil physical and chemical properties had obvious differences in the wild fruit forest of the western Tianshan Mountain. The soil organic matter and total nitrogen content showed a trend of first decrease and then increase but the total potassium content showed a gradually increasing trend. The preliminary conclusion shows that total potassium content and N/K in soil are the main soil limiting factors on the diversity of wild fruit forest communities, which is most probably caused by nutrient-restitution of livestock excrement.

Key words: grazing disturbance, wild fruit forest, species diversity, soil factors, plant community