Diversity Analysis of Ground Cover Plant Communities of Seven Forest Parks in Guangzhou

Taking the ground cover plants of seven forest parks in Guangzhou as the research object, a total of 79 quadrats were set up, and the frequency of plant occurrences in the quadrats was counted. It belongs to 58 families and 90 ge-nera, including 41 species of herbs, belonging to 25 families and 39 genera; 54 species of woody plants, belonging to 34 families and 47 genera; 1 species of vines, belonging to 1 family and 1 genus; 3 species of ferns, belonging to 3 families and 3 species. The frequency of plant appearance showed that the ground cover in Guangzhou Park was dominated by herbs, with more woody plants and fewer ferns and vines. Herbaceous plants are mainly foliage plants, and there are few coleus plants; there are more coleus plants in woody plants. There are various types of ornamental plants, flexible plant collocation, and rich landscaping levels. Provide data reference for the application of ground cover plants in urban park green space landscape construction.


Introduction
In the traditional concept, ground cover refers to all plants that can cover the ground are called ground cover, including herbs, dwarf bushes in woody, weir-like or semi-vine shrubs or vines (Chen, 1988). Yu Yang and Qin Kuijie that ground cover generally refers to low plant community, there is coverage (Wang & Qin, The research on ground cover plants started late, but in recent decades, a lot of research work on garden ground cover plants has been carried out at home and abroad, and some progress has also been made (Hu, 2001;Wei, 1994;Zhang, & Xia, 2003;An, 2007;Shi, 2002;Fukushima & Li, 2002). The research mainly focuses on several aspects: the investigation, introduction and screening of ground cover plants. The domestic related research began after 1970, and the foreign countries were slightly earlier than the domestic ones. Both of them have achieved relatively rich results. Domestic research provides a major theoretical basis for the development of ground cover plants in my country, and is also of great significance in ground cover planting; research on the adaptability and tolerance of ground cover plants, mainly to study the shade tolerance, cold tolerance and salt and alkali tolerance of plants Sex (Cao, 2015).

Materials
Guangzhou is located between 112 degrees 57 minutes to 114 degrees 3 minutes east longitude and 22 degrees 26 minutes to 23 degrees 56 minutes north latitude. There are abundant light and heat resources in this area. The annual average sunshine hours exceed 1500 hours, and the annual average temperature is 21.4˚C ~ 22.0˚C. The temperature in July is the highest, the average is 28.7˚C, and the lowest in January is 14.0˚C. The annual average precipitation is 1784 mm, and the annual average relative humidity is 75%; the frost free period is more than 340 days.
The survey was conducted from February 1 to June 1, 2019. The investigation of species composition adopts the method of minimum area to count the species list of a community. Ground cover is an indispensable part of landscaping, especially the greening of parks plays an important role. By studying the ground cover plants in various parks, this paper analyzes the application of ground cover plants and the landscape construction of ground cover plants, and lays the foundation for the application research of garden ground cover plants in Guangzhou parks. The ground cover plants used in this paper are "plants with a growth height below lm, dense branches and leaves, planted in patches, with strong expansion ability, and can cover the ground" (Song, 2001). The main parks in Guangzhou were inspected, and seven comprehensive parks in Guangzhou were finally se-

The Quadrat Setting and Survey
Quadrat setting refer to the principles of comprehensiveness, representativeness, and typicality (Wang & Deng, 2014;Liu & Mao, 2012;Zhu, 2002). In seven parks including Yuexiu Park, Tianhe Park, and Liuhua Lake Park in Guangzhou, the ground cover plants at various locations in the park were selected. In the landscaping area, a 10 m × 10 m quadrat was set up. A total of 79 quadrats were investigated. The types of groundcover plants in the quadrat were counted, photographs of the groundcover plant landscape were taken, and the collocation of groundcover plants was recorded and analyzed.

Number of Occurrences and Frequency Calculation
The frequency of occurrence of a certain plant = n/N × 100%, n is the number of occurrences of a certain plant, and N is the total number of surveyed fields.

Composition of Ground Cover Plants
According to the investigation, among the seven comprehensive parks in Guangzhou, there are 99 species of ground cover plants in parks, belonging to 58 families and 90 genera. Among them, 41 species of herbs belong to 25 families and 39 genera. There are 54 species of woody plants, belonging to 34 families and 47 genera, 1 species of vine, belonging to 1 family and 1 genus. There are 3 species of ferns, belonging to 3 families and 3 species (Table 1).

Application Analysis of Herb Ground Cover
As can be seen from Table 2, the types of herbs in the ground cover in Guangzhou Park are relatively rich, with 11 kinds of herbs being used more than 10%  (Table 2).

Analysis of Woody Ground Cover
From

Discussion
Based on the classification of ground cover plants and the related theory of ground cover plant landscape construction. Seven representative comprehensive parks were selected, and 79 quadrats were set up. The plant species in the quadrats were recorded, and the plant configuration was photographed and analyzed. Through research, the ground cover species are classified as herbs, woody, vines and ferns.
Through the analysis of the survey data, the following conclusions are drawn. The ground cover plants in Guangzhou Park are mainly herbs and woody plants, and ferns and vines are only a few. The proportion of leafy plants is small, most of them are shade-tolerant or shade plants, and the proportion of woody plants is relatively large.
A variety of plants of the same color can be used for planting in plant pieces, which will not affect the landscape effect but also increase the species diversity of the plant community. When mixing and planting plants, it is not advisable to choose too many plants, which can create a sense of hierarchy, and the primary and secondary can be clearly defined.
Most parks have unreasonable planting arrangements at the initial stage of planting, and some plants grow poorly due to later growth competition. Different planting densities lead to poor landscape viewing effects of ground cover plants. The planting density of planted ground cover plants should be adjusted reasonably. Avoid this happening again.

Conclusion
Taking