By taking parts of Mt. Gaolan and the Xujiashan Experimental substation

General Extension Station of Forestry Science and technology of Gansu Province as examples

the coverage of vegetation communi-ties

importantvalue of differentcommunities

and species diversity in artificial vegetation region

enclosed region

and contrastregion were investigated. The resultindicates thatas long as the tree varieties are prop-erly chosen and technological measures for afforestation are suitable to local conditions

the ecological envi ronmentin the area similar to thatin the north mountain of Lanzhou City can be gradually improved. In addi? tion

the enclosure measure is proved to be an effective way for vegetation restoration in the region. The artificial vegetation species

in terms of their importantvalues

rank in the descendantorder of Caragana microphylla

tamarix ramosissima

Platycladus orientalis

A mmopiptanthus mongolicus

Nitraria sibirica

Lycium chinense

Prunus aymeniaca

and Prunus daridiana. Under any circumstance

Reaumuria soongorica and Symp egma regelii Bge are dominantspecies

showing a strong adaptation to local environment. Diversified index

evenness index

and richness index of artificial vegetation are close to those in enclosed forestregion and differ greatly from those in contrastregion. Using comparability comparison methods

we can conclude thatartificial vegetation region

enclosure region and contrastregion have greater differences in the comparability analysis. With the constantincrease of species quantity and types in forest

the three areas themself will demonstrate greater differences.