Evaluation And Zoning On Environmental Suitability Of Tea Cultivation In Different Districts Of Southern Shaanxi

As the indigenous region of tea plant [Camellia sinensis(L.)O.Kuntze],China has nearly 5,000 years of cultivation history.QinBa Mountains area in southern Shaanxi is the northernmost point of the natural distribution of Chinese tea plant.With good sunshine conditions,abundant rainfall and better natural environment,it basically meets the growth requirements of tea plant,and the tea industry is also one of the leading industries for farmers in the southern Shaanxi region to shake off poverty and become rich.Environmental conditions have a significant impact on the growth of tea plant.The process is extremely complex and long.In order to better adapt to the requirements of the rapid development of the tea industry and avoid blindly expanding the planting scales,this study based on the ecological characteristics of tea plant,to analyze and identify the key environmental factors affecting tea cultivation in southern Shaanxi from the aspects of climate,soil and topography.Those key factors were used as indexes for ecological evaluation to evaluate suitability of tea cultivation in this area,and divide the suitable area.This study has important guiding significance for the rational utilization of regional ecological resources and the formulation of tea industry planning.The main results are as follows:1.The influence degree of different meteorological factors on the growth of tea plant was quantified.In this study,the date of meteorological factors and tea yield of the eight major tea producing counties(districts)in southern Shaanxi from 2007 to 2016 were taken as objects.The grey relational analysis was used to study the correlational between meteorological factors and tea yield in the tea regions of southern Shaanxi.The results demonstrated that in terms of climate,the temperature and humidity in the environment are the two main factors affecting tea production in southern Shaanxi.2.Define suitability evaluation and zoning indexes.In this study,we quantified the effects of climatic factors on the growth of tea plant and combined the results of previous studies,finally determined ten external environmental factors affecting the growth of tea plant: five climatic factors such as annual average temperature,extreme minimum temperature,extreme maximum temperature,annual precipitation,and relative humidity in air;two soil factors such as soil texture and soil type;three topographic factors such as altitude,slope,and aspect.3.Evaluation of tea cultivation suitability in different areas of southern Shaanxi.With the help of the GIS platform,the single factor evaluation of the ten factors affecting the growth of tea plant was performed,and the single factor suitability distribution evaluation maps were obtained.At the same time,using the analytic hierarchy process to determine the weight of different factors,and the results passed the consistency test.Based on the single factor evaluation and the corresponding weights,zoning map of tea cultivation suitability in southern Shaanxi was generated through the ArcMap technology platform.4.Analysis on the results of tea cultivation suitability zoning in different districts of southern Shaanxi.The evaluation area is divided into three tea cultivation suitability regions,which are suitable regions,secondary suitable regions and unsuitable regions.As a whole,the area suitable and secondary suitable for tea cultivation in southern Shaanxi is large,accounting for 96.87% of the total zoning area.The suitable regions are mainly distributed in the hanjiang valley,danjiang river basin and other hilly regions.Which mainly includes the elevation of 200 to 900 m in Lueyang Ningqiang,Nanzheng,Mianxian,Hantai,Chenggu,Yangxian,Xixiang,Zhenba,Zhenping,Shiquan,Hanyin,Ziyang,Lan’gao,Hanbin,Pingli,Baihe,Shangnan.The secondary suitable regions are mainly distributed in some high mountain regions,the altitude is 900 to 1200 m.Which mainly includes Ningshan,Zhen’an,Zhashui,Shanyang,Danfeng,Shangnan,Lan’gao,Pingli and Zhenping.Unsuitable area is less,mainly distributed in some parts of more than 1200 m mountain regions,including Lueyang,Ningqiang,Mianxian,Liuba,Nanzheng,Xixiang,Ningshan,Shiquan,Xunyang,Baihe,Pingli,Zhenping,Shanyang,Danfeng.