Abstract: As the most sensitive component of water expenditure of farmland in arid region, evapotranspiration is a key component of water and energy balance in oasis ecosystems. Shelterbelt is an important ecological barrier to oasis farmland in arid region, with undeniable impacts on evapotranspiration of oasis farmland. In this study, the impacts of distribution patterns of farmland shelterbelts on oasis evapotranspiration were studied in the typical watershed of the north slope of the Tianshan Mountains in Xinjiang. The results showed that the shelterbelts can not only effectively reduce the evapotranspiration of oasis farmland, but also maintain the relatively stable evapotranspiration at a relatively low level at a certain extent. For the pattern function of the shelterbelts, there was a significant and negative correlation between the ratio of belt to patch and the evapotranspiration of shelterbelts (P<0.01), the ring degree and farmland evapotranspiration were negatively correlated (P<0.05), while the connectivity had no significant effects on evapotranspiration (P>0.05), indicating that the distribution density of shelterbelts and the degree of formation of shelterbelt network structure had significant effects on farmland evapotranspiration, whereas the connectivity of the shelterbelt network with basic grid shape had no effect on evapotranspiration. Our results suggest that studying the impact of shelterbelt pattern on evapotranspiration at the landscape level would be helpful for the planning and management of farmland shelterbelts.

Key words: intercropping, redundancy analysis., carbon source, principal component analysis, mulberry