Study Of The Bamboos Planted In Coastal Sandy Soil On The Resistance To Wind,Salt And Drought

At present, the kind of tree in the coastal shelter belt is always single so that the quality of shelter forest decline appears the difficult second-generation renovation. Bamboo is a perfect vegetation, especially, Dendrocalamopsis oldhami, Dendrocalamopsis vario-striata, Dendrocalamus latiflorus, Dendrocalamopsis beecheyana var. pubescens, Dendrocalamus brandisii, Dendrocalamus minor var. amoenus. Due to its superior properties like short growing cycle, wide accommodation and usage, bamboo has constantly attracted the attention of scientists and researchers. At the same time, bamboo shoot has high-yield and abundant nutrition, also bamboo wood has high value in use. For the rhizome of bamboo is mutual interlock, the ability of self-reproduced of bamboo is very strong. Bamboo is adapted to grow in the climate of southeast coastal. So, bamboo is introduced into the coastal sandy soil, in order to improve the soil fertility and the structure of the kind of tree in the coastal shelter belt and realize the coastal shelter forest management of the sustainable development. Finally bamboo forest is to achieve high economic benefit, as well as social benefit and ecological benefit. The paper that studied on the resistance to wind, salt and drought of bamboo, which mixed with the Casuarinacae, the result as follows:(1) Under the salt and water stress, the membrane permeability of D. latiflorus,D. minor var. amoenus,D. brandisii gradually declines ,followed by the time of stress and the intension of stress. For the cell velum is seriously destroyed under salt and water stress. The stronger the intension stress, the bigger membrane permeability. On the contrary, the membrane permeability becomes smaller. By analysis of variance, the membrane permeability of bamboo has extremely remarkable difference, following the time and intension of salt stress.(2)Under light salt stress, the net photosynthesis speed of different bamboos is not different. It declines largely with the time of salt stress and the intension of salt stress. The declining scope of the net photosynthesis speed of Dendrocalamus minor var. amoenus is the largest, then Dendrocalamus brandisi,D. latiflorus is the smallest. The variety regularity of the light respiration and dark respiration speed is the same as that of the net photosynthesis speed. By analysis of variance, with the time of salt stress and the intension of salt stress, the dark respiration speed of the bamboo has extremely remarkable difference. Under water stress, the variety regularity of net photosynthesis speed, the light respiration and dark respiration speed of three kinds of bamboos gradually declines, with the time of water stress and the intension of water stress.(3)With the time and intension of salt stress, the content of chlorophyll varies slightly, and declines obviously. The declining extent of chlorophyll. a is smaller than that of chlorophyll. b. The content of chlorophyll under the intensive water stress declines larger than the middle water stress. The chloroplast of bamboo is lightly destroyed under the middle water stress.(4)The larger the consistency and time of salt stress, the worse the ability of leaves' keeping water. The ability of D. latiflorus is the biggest, D. minor var. amoenus is the second,and then is D. brandisii. Under water stress, the variety regulation of the ability of leaves' keeping water is the same as that of salt stress. The content of losing water of the bamboos' leaves under the stronger water stress is larger than that under the middle water stress.(5)Under water and salt stress, the relatively water capacity of bamboos declines by the consistency and time of stress, the water saturation deficient is opposite.(6)The variety of the containing N, P and K of bamboos is related with the time and intension of water and salt stress. Under salt stress, the containing N, P declines by the consistency and time of stress. On the contrary, the containing K increases gradually. Under water stress, the containing N, P and K of bamboos under the stronger water stress varied largely than that under the middle water stress.(7) Through to generally evaluate three kinds of bamboos on the resistance to salt and drought, it concludes that the ability of Dendrocalamus latiflorus on the resistance to salt is the biggest, D. brandisii is the second then is D. minor var. amoenus. Under the middle water stress, it shows that the ability of D. minor var. amoenus on the resistance to drought is the biggest, D. latiflorus is the second then is D. brandisii. Under the intension water stress, it results that the ability of D. latiflorus on the resistance to drought is the biggest, D. minor var. amoenus is the second then is D. brandisii.(8)Among the introduced bamboos, fiber length of different parts of bamboos has extremely remarkable differences. And fiber length in the lower part of stem is longer than that in the higher part of stem. So is the fiber length of old bamboo. As to fiber length of old bamboo, the big to small order shows: D. minor var. amoenus, D. vario-striata ,D. oldhami, D. latiflorus, D. beecheyana var. pubescens and D.s brandisii.(9)The main physical and mechanical properties of different bamboos have remarkable differences: As to shearing strength parallel to grain of bamboo, the big to small order shows :D.minor var. amoenus,D.vario-striata,D.oldhaml,D.brandisii,D.beecheyanus var. pubescens and D.latiflorus. As to compressive strength parallel to grain of bamboos, the big to small order shows: D.minor var. amoenus,D.vario-striata, D. beecheyana var. pubescens,D.brandisiiJ).oldhaml and D.latiflorus. As to bending strength of bamboos, the big to small order shows: D.minor var. amoenus,D.vario-striata,D.brandisii,D.oldhaml,D var. pubescens and D.latiflorus. As to modulus of elasticity of bamboos, the big to small order shows :D.?mwor var. amoenus,D.oldhamlJD.var. pubescens,D.brandisii,D.vario-striata and D.latiflorus. As to toughness of the wet wood of bamboos, the big to small order shows:D.minor var. amoenus,D.vario-striata,D.oldhaml,D.latiflorus,D.brandisii and D var. pubescens. As to toughness of the dry wood of bamboos, the big to small order shows:D. amoenus,D.vario-striata,D.latiflorus, D.brandisii,D.pubescens and D.oldhaml.(10) The main physical and mechanical indexes of bamboo wood are nearly related to fiber length (L) and fiber width (W). The relation between these indexes and L/W ratio, air-dried density and basic density is not remarkable while the correlative coefficient is very small. The relationship between fiber length and mechanical indexes is the largest. The larger...