Investigation And Diversity Of Cliff Plants In Wulingyuan Based On UAV Close-up Photography

Wulingyuan National Forest Park is located in the northwest of Hunan Province.There are 3,103 stone peaks in this area,which are distributed at 200-1200m above sea level.The abundant quartz sand peaks are tens to hundreds of meters high,and there are abundant cliff plant communities growing on them.The cliff is the exposed surface of the rock vertically or nearly vertically(generally refers to the slope>70°).And cliff plants refer to the plants living on the cliff face.Due to the lack of investigation means,has not been a massive investigation and study.However,the investigation and research of cliff plants is of great significance to determine the pioneer plants under extreme site conditions such as rocky desertification and drought,and improve the ecological conditions of rocky desertification and arid areas.In this study,UAV close-up photography was used to investigate cliff plants.The feasibility of this method was tested by field investigation,indoor data search and plant identification.The diversity of cliff plants in Wulingyuan quartz sandstone was investigated and a database of cliff plants was established.At the same time,combined with the cliff plant data collected on the cliff plants and cliff top plants to compare the differences.The variation trend of cliff plants with light,altitude,site conditions,humidity and road was analyzed,and the influencing factors of quartz sandstone plants were discussed.The results of this study were as follows:(1)A total of272 species of cliff wall plants belonging to 142 genera of 55 families and 172 species of cliff top plants belonging to 117 genera of 62 families were found in this survey,which were collected by the method of UAV close-up photography and sample plot survey.This practice proves that UAV close-up photography can be a new method for the investigation of cliff plants.(2)There is no significant difference between the dominant plant species of the Wulingyuan quartz sandstone cliff top and cliff wall plants.But the species richness of the cliff top plants is higher than that of the cliff top plants,and the uniformity of the cliff top plants is obviously higher than that of the cliff wall plants.There are 79 species belonging to 55 genera and 33 families on the original cliff tops,114 species belonging to 85 genera and 50 families on the disturbed cliff tops.Of these,23 families are found in both types of cliff tops.The plant richness of native cliff tops was higher than that of the cliff tops disturbed by human activities,but the diversity index and evenness index of native cliff tops were lower than that of the cliff tops disturbed by human activities.(3)The relationship between cliff plants and natural factors such as altitude,light and site conditions was studied.It was found that the species number and altitude of cliffs obeyed normal distribution.And the number of species reached the peak at 700-800m above sea level.Simpson index and Pielou index reached the highest at low altitude,and decreased with the increase of altitude.The species composition,dominant species and occurrence frequency of cliff plants were different in different site conditions.The correlation analysis of the influence factors of the cliff plants showed that there were different significant relationships among the indices of the cliff plants under different illumination conditions or different site conditions.The comparison of plant analysis results under different humidity showed that the area with higher humidity had richer plant species.According to the analysis of the road buffer zones,the dominant species and plant diversity of the cliff plants in Wulingyuan did not show a specific rule with the distribution distance of the road,nor did the dominant species of the cliff plants change significantly between the buffer zones.(4)On the basis of field investigation,the related information of cliff plants was collected and sorted out.And the database of cliff plants was established.