Study On Afforestation Technology In Semiarid Region Of Northwest Hubei Province

This paper studied the distribution characters of rain quantity and heat quantity. Accordingly, the afforestation technology tests, which included afforesting in multi-seasons, planting by mulching plastic, and by using water-retaining agent, and the drought-resistant physiological characters studying through water stress tests of potted plant, had been carried out in the past years. The results showed that the climate in the northwest of Hubei province could be divided into two districts: northwest river valley low mountain tepid semiarid region and southwest hilly mildness half-moist climatic region. In six nursery stock for tests, Couninghamia lanceoLata Caragana microphylla Robinia pseuidoacacia and Platycladus Orientalis are low water potential energy drought resistance tree, Pinus elliottii and Hippophae rhamnoides are sub-low water potential energy drought resistance tree; Stressed under the condition of the moisture content, the bound water content, the leaf blade thickness and the leaf area were obviously reduced, and the speed of net photosynthesis and transpiration both were obviously dropped, and efficiency of the moisture content reduced along with the arid progress; By synthetically analysed the change of nursery stock's shape characteristic, moisture physiology and the metabolism physiology, we found that the nursery stock for tests all exhibited the drought-resistant physiological characters, but compared with Pinus elliottii engelm, Couninghamia lanceoLata, Robinia pseuidoacacia and Hippophae rhamnoides, the characters of Caragana microphylla and Platycladus orientalis are stronger; Afforesting in different seasons enhanced the survival rate of trees greatly, compared with in spring, the survival rate was enhanced by 30%, and the difference is remarkable; The nursery stock growth quantity could be enhanced by 1.6 ~ 6 times, the difference is wondrously remarkable; Regarding the different trees, the survival rate of trees planted in middle or late autumn is different. The survival rate of broad-leaf tree planted in late autumn, such as Robinia pseuidoacacia and Hippophae rhamnoides, is obviously higher...