Study On The Rules Of Water Consumption Of Dominant Tree Species And The Community Of Artificial Forest In Mountain Area Of Northern China

This article mainly researches water consumption properties of common tree species and the water consumption mechanism of typical stand and tree in Miyun reservoir watershed in Mountain Area of Northern China .Reveal characteristics and rules of water consumption of different species. On the basic of the analytical results, combine soil-water movement in the woodland; establish the scale-transition model of water consumption of forestContraposing the existing vegetation of Miyun reservoir watershed, choosing 22 kinds of shrubs and two pieces of typical forest stand as research object, obtain following conclusion by pot experiment and experiment of typical forest stand, field and experimental research, applying statistical method to analyze water consumption properties from the seedlings to single plant to forest stand. The main conclusion is as follows:Because of biological characteristics of different tree species, form different Ecological Adaptability. At water enough condition, 22 tree species of the young plant used in the experiment whose tendency of transpiration rate, photosynthetic rate and the diurnal changes of water use efficiency are similar. The transpiration rate of arbor trees is higher than Coniferous Trees', but in the average efficiency of using water, Coniferous Trees is greatly higher than arbor trees'. The transpiration rate of positive shrub species is greatly higher than negative shrubs species', but in the average efficiency of using water, negative shrubs species is greatly higher than Coniferous Trees'. According to the correlation analysis of transpiration and environment factor, the result is: solar radiation and stomataconductance have a crucial effect to trees transpiration. According to the correlation analysis of transpiration and environment factor, the result is: solar radiation and stomata conductance have a crucial effect to trees transpiration. And meanwhile, Mathematical model of multiple linear regression of transpiration rate and environment factor has been built up: Y=a+bX₁+cX₂+dX₃+eX₄+fX₅.The correlation coefficient greater than 0. 9.Under the water control condition, comparion the rule of photosynthesis, the rule of transpiration and the change of stomata conductance of different tree species, conclude that different tree species of the seedlings on photosynthesis and transpiration rate descend with the time of water control extending. Because of the special biological configuration and longer time of water control, several tree species are preferable material in choosing fight a drought tree species, such as Platycladus orientalis, Pinus tabulaeformis, Quercus. Dentate, Q. variabilis, Rhamnua davurica and Corylus heterophylla and so on.At water enough condition, in respect of water consumption daily, comparing of Characteristic and law of water consumption day and night, water consumption rate diurnal Course to comparing analysis 22 tree species used in the experiment, conclude that: 7 arbor tree species' rate are 0.71 g/cm²,15 shrubs species' rate are 1.00g/cm². The water consumption of Chinese Pine is higher than Chinese Arborvitae. Among them, The comprehensive sequencing on water consumption of kargeleaf arbor tree is: Acer truncatium >Quercus. variabilis >Rhus chinensis >Quercus. dentata >Robinia pseudoacacia. The comprehensive sequencing on water consumption of bushes is: Deutzia scabra>Rhamnua davurica > Vitex negundo Var.heterophylla >Rungia Chinensis >Cotinus coggygria >Spodiopogon sibiricus> Andrachne chinenSis >Spiraea trichocarpa >Syzygium aromaticum >Myripnois dioica >Corylus heterophylla >Lespedeza bicolor>Rhus typhina>Amorpha fruticosa>Indigofera kirilowii. In general, the amount of water consumption of broad-leafed trees' is bigger than Coniferous Trees' and the amount of water consumption of shrub species is bigger than arbor trees'.In the similar microclimate conditions, the biological characteristic of variety kinds of trees is the major factor to influence the transpiration of trees. The transpiration rate, photosynthetic rate and water utilization efficiency of 15 kinds of experiment trees of typical forests have the similar change directions of their daily variation curves. The maximum transpiration rate of Chinese Pine is higher than Chinese Arborvitae. The order of daily maximum transpiration rate of broadleaved arborous tree speciesfrom high to low is: Ailanthus altissima> Sawtooth oak> Live oak> Robinia pseudoacacia> Quercus variabilis. The same order of shrub species is: Buckthorn> Cotinus coggygria> Sour jujube> Rungia Chinensis > Heterophyllous negundo chastetree>Rhus typhina>Kirilow indigo> Chinese leptopus. All kinds of trees' water utilization efficiency were reducing. Some arborous tree species have the highest water utilization efficiency, such as Chinese Pine, Quercus variabilis, Sawtooth oak and Chinese Arborvitae. The water utilization efficiency of coniferous species is higher than broadleaved species. Some shrub species have low water utilization efficiency such as Rungia Chinensis, Buckthorn, Cotinus coggygria, Kirilow indigo and so on. On the basis of analysis of the transpiration rate and environment factor, we can know that transpiration rate and the stomata conductance and the intensity of illumination are significant correlation. So build the multivariate regression model of the transpiration rate and environment factor: Y=a+bX₁+cX₂+dX₃+eX₄+fX₅, the coemcient of association is higher than 0.9.The transpiration rate can express a composing index of water consumption properties of tree species, but cannot completely reflect how large the water consumption properties of tree species are. Only at the same time determining the transpiration rate of leaves and achieving the area of the whole canopy of a tree, can we find the water consumption rate or the water consumption. We can find that from comparing the water consumption among different species, the water consumption of Robinia pseudoacacia is the highest, and the order of the water consumption is: Robinia pseudoacacia > Ailanthus altissima > Quercus acutissima > Q. dentata > Pinus tabulaeformis > Quercus variabilis > Platycladus orientalis.The main approach of the water consumption of forest stand contains three factors, such as crown interception evaporation, transpiring water-consumption of plants and soil water physical evaporation. Atmospheric precipitation gets through forest canopy, which is a redistribution process about rainfall. According to water balance principle and ignore water change in horizontal direction, conclude the sequence of the interception rates as follows: Cotinus coggygria>Vitex negundo Var.heterophylla > Quercus acutissima >Robinia pseudoacacia >Pinus tabulaeformis >Quercus. Dentate >Platycladus orientalis > Ailanthus altissima. The litter layer interception of Pinus tabulaeformis is about 10.42% in whole precipitation, and Platycladus orientalis is about 9.49% in whole precipitation. Soil water evaporation is a special form during soil water movement. Average evapotranspiration per month of thesoil water whose change assume peak curve in the year. Under the typical clear day condition, daily evaporation of soil water mainly happens in horizon of soil from 0 to 20cm.Water consumption of forest stand is a main output in water balance of forest ecosystem. According to oriented flux method and water balance method accounts measuring water consumption of forest stand. The conclusions are as follows: total water consumption of the Pinus tabulaeformis is 516.52mm in growing season,and the average daily water consumption is 2.74mm, and crown interception is about 25.63% in whole interception, and soil evaporation is about22.15% in whole evaporation, and water consumption of plants is 52.22%in whole water consumption of plants; total water consumption of the mixed forest of the Arborvitae and oak is 527.26mm, and the average daily water consumption is 2.73mm, and crown interception is about 23.66% in whole interception, and soil evaporation is about28.38% in whole evaporation, and water consumption of plants is 47.95%in whole water consumption of plants; total water consumption of the shady slope is 499.0mm, and the average daily water consumption is 2.73mm.The water consumption of forest stand is the chief output item of water - balance of the forest ecosystem. The calculation results is nearly the same though two methods that oriented flux method and water balance method, the result is: the amount water consumption of Chinese pine forests in growing season is 515.3mm, daily average water consumption is 2.74mm, canopy interception account for 25.69%, soil water evaporation account for 22.20%, plants' water consumption account for 52.35%; The amount water consumption of the mixed forest of Chinese arborvitae with oak is 512.8mm, daily average water consumption is 2.73mm, canopy interception account for 24.33%, soil water evaporation account for 29.96%, plants' water consumption account for 49.31%; The amount water consumption of schattenseite bare soil is 499.0mm, daily average water consumption is 2.73mm.Build the relationship in forest stand water consumes, soil water and water movement is the line of thought of module construction. This research improve on the forest water consume model from PhD Shi Qing. On basis of analysis the alteration of the soil water potential, use math method, make forest roots system into a circular cone, and then divide this circular cone into n circular truncated cones. Calculate them separately. At last, a forest consume model (including competition model and no competition model) has been built up.Forest water consume model:Ri is the distance from the center of root system to the edge of area of influence, named influenced radius; B is the distance of the neighboring two trees.Using it with the growing model of forest or forest stand can simulate single tree or forest stand's process of water consumption in different time slot and different tree species from young growth. It can also simulate the alteration of water consumption of forest stand, and the gross quantity of water consumption of forests or forest stand during their whole life.