Study on regional characteristics of plant landscape in yao village of longsheng county

. Taking the plant landscape of Baimian Yao Village and Huangluo Yao Village in the regional environment of Longsheng Autonomous County as the research object, combing and analyzing the status quo of their plant species and plant communities, and combining the folk culture and living area of the minority ethnic group in Guangxi—the Yao nationality,it summarizes the characteristics of plant landscape such as the application of native plant varieties, the level of plant vertical landscape space, and the combination of plant application and folk culture. In order to provide theoretical and practical guidance for the future plant landscape construction in this area.


Introduction
Regionality refers to the comprehensive characteristics of a certain area under the influence of the natural environment, things and activities, and historical and social context [1] .The time category of the concept of regionalism is variable,it not only refers to the comprehensive characteristics of a region in a specific space-time background, but also refers to the regional comprehensive characteristics presented by a region in the process of time, which has the characteristics of changing with time [2] .With the development of globalization and the improvement of economic foundation, people's requirements for the quality of plant landscape are increasingly high, the highly distinctive garden plant landscape has become the aesthetic object that people expect, there is also mutual learning and reference in the construction of plant landscape between different regions. In this process, problems such as "one thousand cities, one side of the same landscape in different regions" appeared in the rural landscape design，so it is very necessary to develop and protect the regional landscape of garden plants [3] .
As one of the basic types of traditional settlements, the landscape features of ancient villages have been enriched with the historical process of human settlement activities [4] .In the context of ecological civilization, the economy has driven the rapid development of tourism， due to the long-term effect of modern elements on the traditional ethnic minorities, the plant landscape in the traditional ethnic minority villages is affected by the urban and rural greening pattern, and deviates from the traditional construction method of ethnic local plant landscape.Minority folk villages contain rich ethnic history and culture as well as distinctive ethnic local features and features, they often form ethnic minority villages based on the characteristic natural landforms and combined with their own living customs and cultural traditions. Therefore, to study the regional characteristics of plant landscape in a few folk villages is not only conducive to coordinating the development, protection and coordinated development of traditional ethnic villages, but also helpful to provide basic information and design ideas for local rural landscape planning and urban garden design.

Overview of the study area
Longsheng County, located in the northeast of Guangxi, is a south subtropical monsoon climate zone [5] .There is plenty of sunshine and rainfall, and the average temperature is 18.1 degrees Celsius. There are four types of soil: yellow brown soil, yellow red soil, red soil and yellow soil. Its zonal vegetation is dominated by subtropical monsoon evergreen and deciduous mixed forest, with diverse plant habitats and rich species [6] .The forest coverage rate is as high as 76.9%, including woodland, shrubbery, forest and suitable woodland.Among them, economic forest is about 134,000 square hectares, accounting for 65.1%. The other ecological forests accounted for 34.9% of the woodland area. Due to the influence of human activities, the forest native vegetation stock is small, mainly composed of Moraceae, Camelaceae, Hamamelisaceae, Lauraceae, Araceae and other species of plants.

Survey contents and methods
Plant landscape is an indispensable part of environmental construction, and shows the overall plant style and landscape construction level. Taking into account the history, construction characteristics, conservation and management level of a few folk villages and other factors comprehensively, two typical plant communities with good effects in two folk villages were selected to take photos and draw the plan. The plant name, number (tree record, shrub and grass record tree/cluster number), plant community structure, DBH, crown width or tree degree, crown height and growth and development information in the survey area were recorded.

The regional characteristics of plant species of Yao nationality in Longsheng
A field survey of plant species in two typical ethnic minority villages in Longsheng Autonomous County was carried out,a total of 66 species of garden plants, belonging to 49 families and 62 genera, were counted. According to the distribution of families and genera in the region, the plants in the survey area are mainly subtropical species, mainly distributed in Moraceae, Camelliaceae, Araceae, Rutaceae.According to "Flora of Guangxi", the native plants and exotic plants in the tree layer accounted for 76% and 24%, respectively, according to the statistics of plant sources in the region;the proportion of native plants and exotic plants in shrub layer was 80% and 20%, respectively, the proportion of native and exotic plants in herbaceous layer was 88% and 12%, respectively. Therefore, in the plant landscape communities of Baimian Yao Village and Huangluo Yao Village, there are abundant and diverse native plants planted in the arboreal layer, and the proportion of exotic plants in the arboreal layer is large. The main native tree, shrub and herb species with high planting amount are shown in Table 1. It can be seen from Table 1 that the local plant resources in the counties and autonomous regions of Longsheng are not only rich in application, but also highly adaptable and of high ornamental value, which provides guarantee for the biodiversity and ecosystem stability of a few folk villages. While planting local plants in a reasonable way, the planting of exotic plants in a few folk villages also takes up a certain proportion.The exotic plants have been cultivated and domesticated for many days and months, and have been adapted to the local environmental conditions and shown a good growth state,they have played a positive role in enriching the biodiversity of a few folk villages and constructing the landscape of plant communities. The species of exotic trees, shrubs and grasses with high planting amount are shown in Table 2.

The regional characteristics of the plant community of Yao nationality in Longsheng
Plant community refers to the combination of all plants living in a certain area, which is formed by mutual influence of each individual plant through reciprocity and competition, and is the result of their adaptation to the common living environment. Each relatively stable plant community has certain species composition and structure [7] .In this study, the plant planting collocation in the two selected typical minority folk villages was investigated and statistics were made, and the community structure and ornamental characteristics were analyzed, and 8 plant communities with rich structure and high ornamental value were obtained ( Table 3).As shown in Table 3, the plant communities in a few folk villages take native plants as the backbone tree species and exotic plants as the ornament, so that the composition of the plant communities can most intuitively express the natural plant landscape with regional characteristics.

Summary of regional characteristics of Longsheng Yao plants
Both Baimian Yao Village and Huangluo Yao Village have remarkable characteristics of native plants. In the application of native plants in the landscape, the two Yao villages have their own application principles and aesthetic characteristics.Is common, there are some regional plant application such as osmanthus, liquidambar, Chinese beech, eucalyptus, fields such as strong adaptability, growth in good condition of native plant species as the backbone, the plant landscape of the whole ecological function, decoration, space, define functions are rev to the leading role, showing LongSheng County living style and features.The application of some regional plants is unique and has certain aesthetic value and ecological significance, such as the application of fruiting plants such as Orangeberry and Ardisia crenata. For example, the preservation of wild vegetation, such as Polygonum capitatum, climbing groundsel herb, and Cibotium barometz, not only makes the villages' aesthetic features remarkable, but also shows the unique features of the mountainous areas of ethnic minorities. In general, the plant landscape inside the Yao Village in Longsheng County is different from the conventional plant landscape configuration in the general urban park and green space. The plant species selection is rich, the form is characteristic, and the scale and distribution are suitable for the internal space of the village.

Plant landscape characteristics of Yao Village in Longsheng County
Baimian Yao Village and Huangluo Yao Village are both villages with the characteristics of Yao style plant landscape, and are related to the folk culture and living area of Yao minority.Yao nationality is a minority nationality with profound historical and cultural deposits in China. The regional characteristics of its main living environment have created a variety of local plant species, and also increased people's application and love of plants.

Application of native plant varieties
Local plants are plants that are native to the region or have been introduced, cultivated and propagated for a long time, and have many advantages such as adapting to the local natural environment, maintaining the local ecological stability, strong growth adaptability and low maintenance and management cost [8] . Moreover, some local plants are closely related to local legends, allusion and customs.In the greening of traditional villages, the application of native plant varieties is not only conducive to improving the local greening environment, but also can well reflect the regional natural characteristics and traditional local culture of a village.At the same time, because native plants have low requirements for living environment and are easy to survive, the cost of planting and maintenance is relatively low.Therefore, the construction of local plants as the main plant landscape has become one of the important development directions of gardens.

Plant vertical landscape space level
The rational collocation of plants not only makes the landscape spatial hierarchy diverse [9] , but also has different visual senses.Therefore, the plant landscape can be divided into four landscape levels, namely, large tree --small tree, large shrub --small shrub, erect herbaceous --ground covering herbaceous. The top plants are mainly Ficus in Moraceae and Phyllostachys graminae, which are mostly planted at the border of the village to construct the green skyline of Yaozhai. The second layer is dominated by small trees and large shrubs, mostly planted with evergreen or color shrubs and crape myrtle to highlight the seasonal image. The third layer is small shrubs and perennial, erect herbs, the plants are mainly ornamental (flower, fruit), medicinal type;the lowest layer for the floor of the herb can be eaten.Among them, the lianas are shade-resistant and climbing with other plants, while the lianas are sunny and climbing on the bamboo fence, so that the whole plant landscape is connected in series, presenting the stylized style of Yao Village.

The combination of plant application and folk culture
The application of plants in Longsheng Autonomous County is closely related to the culture and folk custom of Yao Nationality.They believe that the tree deity can protect the peace of the village, help the Yao people eliminate disasters and diseases, and bless the Yao people, so the Yao people have the traditional idea of worships trees.Especially for maple trees, Yao people think that maple trees are the incarnation of their ancestor Chiyou and their protectant god [10] .In one of the main courtyars of the village, there is a sacred monument to be worshipped by people.Behind the sacred monument are towering ancient maple trees, which can not be damaged unless they are pruned by special personnel on festivals and festivals.

Conclusion
However, due to the development of tourism, the distinctive style of Yaozhai village has gradually disappeared，first, in the construction of public green space, the planting, variety and pruning methods of plants are the most common and most used in the greening of surrounding towns in these two areas, which destroys the original plant landscape ecology to a certain extent;second, with regard to the greening of the small courtyards in front of and behind the villagers' houses, since Longsheng Yaozhai itself is located in a mountainous region, the available construction area is limited, so the area of courtyards for residents is even more limited.The relevant local departments should strengthen the protection and conservation management of plants to avoid the encroachment of green space or plant space by infrastructure construction, especially in some plants and landscapes with characteristics, such as maple trees.In this perfect the construction of some characteristic regional landscape, and increase the application of native plant varieties. At the same time, combined with the garden characteristics of Yao people, the space of Yao village is decorated to interpret and show the Yao culture.