兰州市北山无灌溉区植被恢复效益初步研究

在陇东半湿润易旱地区,通过大田试验,研究了限量补充灌溉及套作对冬小麦、玉米产量和水分利用效率(WUE)的影响,探讨了冬小麦套作玉米、单作冬小麦和单作玉米地土壤水分的时空动态及利用特性.结果表明,套作可显著提高冬小麦和玉米的产量和水分利用效率,套作耗水量较相应单作耗水量的加权平均增加了5.7%～7.3%,产量提高了52.8%～50.6%;限量补灌对套作和单作小麦的增产作用显著,对单作玉米的WUE也具有显著的提高作用,但对单作小麦和套作WUE的影响不显著;冬小麦套作玉米对水分利用的互补作用主要发生在冬小麦收获后,主要通过利用冬小麦带和深层水分提高利用效率,套作是既可提高旱农区当季降水利用率又可保留适宜底墒水平的高效种植模式.

Preliminary Study on the Benefits of Non-irrigation Vegetation Restoration in the North Mountain Area of Lanzhou City

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.