| This paper systematkally researched the characteristics of growth and physiology of Sophora viciifolia Hance(a kind of natural shrub) and its effects on the content of soil water, soil nutrieftt and soil physical property. The paper applied some methods and theory of plant ecology, plant physiology, physics of soil and soil chemistry etc.Three different age S.viciifolia Hance in the different plot were selected, Caraganar land and fallow land as a comparison. Through investigating their index of growth and soil water content from April to October, observing their species composition in July and above-ground biomass in September, measuring seasonal changes of plant moisture stress, net photosynthesis rate, transpiration rate of S.viciifolia and Hance, after analyzing all kind of data, the following conclusions can be drawn:1. The height of S.viciifolia Hance is 1.5m, crest amplitude is 2.0×2.0m2, the average number of branches is 4.45, and plant coverage is from 75% to 90%. The length of new branch in a year is more than 50cm, and the new branch grows faster in June, July and August. The above-ground biomass amount is between 11.81-109.15t/hm2. S.viciifolia Hance has good funcjtion for soil and water conservation. At present, it is on the frontal stage of natural vegetation succession, the ground-diameter is keeping linear growth. The status of plot determines the plant's growth rate. There is a big difference among species (including 16 fccsetcses).2. The curve of diurnal variations of photosynthetic rate of S.viciifolia shows a one-peak type(maximal photosynthesis rate occurred 10'clock). The most of curves of the diurnal variations of transpiration rate is a one-peak type, a few of them show a two-peak type. Photosynthesis and transpiration have no obvious difference between different age S.viciifolia, but they have consanguineous physiological responses to environmental factors such as photon flux density, air temperature and the content of soil water. Compared with Caraganar, S.viciifolia formed the physiological mechanics of less photosynthetic rate and less tranpiration rate to resist drought. In addition, they have similar water use efficency.3. The curve of diurnal variations of the plant moisture stress of S.viciifolia shows a one-peak type(minimum occurred 12'clock, maximum occurred pre-dawn). The seasonal variations of PMS responses to its growth stage, and PMS increased gradually from April to October. PMS has no obvious relation to age and has good relation to air temperature, photon flux density and air humidity. The pre-dawn PMS is steady. Compared with Caraganar, thedrought-resistance ability of S.viciifolia is stronger.4. The amount of water consumption of S.viciifolia through evaporation and transpiration is 523-590mm, the depth of water consumption is about 2.5m, which is closer to Caraganar's. The consumption of soil water is the most In June and July, minimum occurred in August and began to increase in September. The whole water is supplied by rainfall. S.viciifolia endured slightly water coerce. The water wane of S.viciifolia is less than Caraganar's, they adapt the specific soil water situation under different species composition, population density and vegetation coverage. The content of soil water in the 10m profile shows: the content of soil water is high in 4-6m, there is a soil-drying-layer in 6-8m profile which was formed in the frontal stage of S.viciifolia growth. After two years, it didn't develop further. S.viciifolia has a balance with rainfall.5. S.viciifolia can enrich and accumulate soil nutrients. The content of soil nutrients in 0-20cm profile is higher than that of 20-60cm profile. In the S.viciifolia plot, there are more organic matter, the whole nitrogen, quik-result nitrogen, quik-result kalium. Both S.viciifolia and Caraganar have good activation to quik-result phosphorus. In addition, S.viciifolia can improve soil physical properties. The content of soil aggregation (>2.0mm) in 0-20cm profile is higher than fallow land's and Carag...
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