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In this study, in 2004, Shandong Agricultural University Forestry Experiment Station, with annual seedling trees: Arborvitae (Platycladus orientalis (L.) Franco), black locust (Robinia pseudoacia L.), pagoda tree (Sophora japonica L.), Albizia (Albizia julibrissin Durazz.), Vitex (Vitex negundo L.), Pistacia (Pistacia chinensis Bunge), sumac (Cotinus coggygria SVcinerea), willow (Salix matsudana Koidz), five maple (Acer mono Maxim), poplar (Populus candensis Moench) as the test material. Drought and water control simulation test method uses Hsiao.TC (1973) proposed the design of plants on the division of water gradient method, is divided into four treatment levels: control (ck) 75-80% (representing maximum water holding capacity of the soil percentage); mild stress (T1) 55-60%; moderate stress (T2) 40-45%; severe stress (T3) 30-35%. During the experiment the various species of morphological, physiological and biochemical indexes were continuously measured, tested once every 10 days, a total of 4 times measured, achieved the following results: a comprehensive 10 species survival and external morphology, its ability to endure drought stress relative size as follows: arborvitae gt; Pistacia gt; sumac gt; Acer mono gt; Huang Jing gt; willow gt; Sophora gt; Poplar gt; acacia gt; locust. 2, under drought stress, stomatal conductance decreased, not only inhibiting factor decreased photosynthetic species. Meanwhile, with the stress intensity enhancement, stomatal conductance decreased, increased stomatal resistance, reduce and prevent loss of body water, helps maintain a good body of water balance, improve the body's moisture. Stomatal limitation on the one hand the development of delayed stress, reducing the intensity of photosynthetic organs of coercion, it also induced free radical generation of non-stomatal limitation. 3, with the stress enhancement and stress time, Chla content change show significant downward trend. From Chlb trend can be seen with Chla, Chla reduce variation on Chlb play a certain influence. Stress carotene content of each tree species showed a downward trend, but the extent of decline varies. Stress, the carotene content of each tree species showed a downward trend beginning from each tree species to see the extent of decline carotene, carotenoids Pistacia smaller changes, which may contribute to enhanced drought resistance. 4 associated with osmotic adjustment ability of proline, soluble sugar, soluble protein in the early stages of stress between species showing a varying trend can be seen on the whole drought resistant species
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