Microclimate Characteristics Of Tea Plantation Shelterbelt In Coastal Hilly Region Of Jiaodong, China

With the implementation of the tea planting and the improvement of tea plantation management, the areas for tea plantation has been expanded gradually in Rushan city. Rushan tea has a special geographical environment of North China, together with the quality of irrigation water and atmospheric all meet the construction standard of ecological tea plantation, which provides a favorable condition for excellent quality and texture of tea in Rushan city. But due to the low temperature in winter and early spring, the areas of tea plantation facing the dilemma of development in the north area. However, the winter cold defence with greenhouse is higher in the cost of investment, therefore, how to run the planting area with higher yield and quality at a lower cost has become a major issue of the sustainable development in the test plantation area.In this study, the four sizes shelterbelt of tea plantations(8 m × 80 m, 12 m × 80 m, 20 m × 80 m and 40 m × 80 m) as the research object which planted in the Dongdongling village, Xujia town, Rushan city, Shandong province. There were emplaced observation points in four kinds shelterbelt of tea plantations, the wind speed, air temperature, soil temperature, relative air humidity, relative soil moisture and soil evaporation were measured in April, August and December of 2014, and the tea plantation without shelterbelt as control. The results showed that:Firstly, the four shelterbelt systems can reduce wind speed, and show April>August>December in seasonal regularity, in wind-break potencies the four sizes tea plantations shelterbelt show that 8m×80m>12m×80m>20m×80m>40m×80m in April, August and December.Secondly, the four shelterbelt systems can regulate temperatures, air temperature and soil temperature showed increasing temperature in April and December, and cooling down in August, in air temperature and soil temperature the four sizes tea plantations shelterbelt show that 8m×80m>12m×80m>20m×80m>40m×80m in April, August and December.Thirdly, the four shelterbelt systems have some hydrological effects; the air relative humidity has a certain effect of increasing in April, August and December, soil relative moisture is shown higher than control in April and December, and shown lower compared with the control in August. The soil potential evaporation shown reduces in April, August and December. In air relative humidity、soil relative moisture and soil potential evaporation,the four sizes tea plantations shelterbelt show that 8m×80m>12m×80m>20m×80m>40m×80m in April, August and December.Fourthly, the results of principal component analysis showed that, the main factors inducing different microclimate characteristics were the air temperature and air relative humidity, with factor loads of 0.988 and-0.989, respectively. The results of correlation analysis showed that, the air temperature and wind speed showed a highly significant correlation(p<0.01), there was significant correlation with soil evaporation(p<0.05); There was a significant correlation between air relative humidity and wind speed, soil evaporation, the significant level are respectively p=0.027, p=0.016. Therefore, wind speed and soil evaporation may be indirect factors in inducing different microclimate characteristics.Finally, according to the width of horizontal terrace and the spacing of two roads make up tea plantations shelterbelt with different sizes. Planting one line evergreen species in the terrace and form a single line auxiliary shelterbelts with sparse structure which can reduce the soil coerced. Then planting four line coniferous species and hardwood species in the vertical direction of problem wind and form the tight structure shelterbelts of theropencedrymion. The shelterbelt system of 8 m × 80 m to 20 m×80 m is better than the other systems in the effects of wind speed, temperature and hydrology, and it improved microclimate in favor of tea production, the shelterbelt system can reduce the degree of freezing damage of tea plant, diminish the temperature difference, and ease the drought conditions to ensure adequate water, to promote the stable and high yield of tea in Rushan city.