西鄂尔多斯铁路防护林柠条锦鸡儿和沙冬青对不同管护措施的生理生态响应

 对西鄂尔多斯铁路防护林中滴灌栽植围封、无灌溉栽植围封和天然围封样地中柠条锦鸡儿和沙冬青的生理生态响应特点进行了研究。结果表明:滴灌栽植围封样地中柠条锦鸡儿和沙冬青比另两样地中有较好的水分状况和生长状况,较高的蒸腾速率和净光合速率。两种植物在滴灌栽植样地中蒸腾速率和净光合速率日变化都呈单峰曲线;在无灌溉栽植围封和天然围封样地中的蒸腾速率、净光合速率日变化都呈双峰曲线,有较明显的光合“午休”现象。3个样地间,柠条锦鸡儿及沙冬青的水分利用效率（WUE）差异不显著,说明本研究中的滴灌量没有使植物的WUE低于其在自然降水条件下的值。此外,柠条锦鸡儿对水分条件变化的响应较为敏感,水分条件改善时可大幅提高生产力;而沙冬青对水分条件变化的响应较平稳,水分条件改善时生产力提高幅度相对较小。可见柠条更适合用于建立滴灌人工防护植被,而沙冬青更适合自然状态下的恢复。

Ecophysiological Responses of Caragana korshinskii and Ammopiptanthus mongolicus in Shelter-forest along Railway in Western Ordos to Different Management Measures

This paper studied the ecophysiological response characteristics of C. korshinskii and A. mongolicus in drip-irrigation enclosed site, no-irrigation enclosed site and natural enclosed site in the shelter-forest alone the railway in the western Ordos, in order to provide scientific proof for better maintaining the stability of shelter-forest along railway. The results showed that the C. korshinskii and A. mongolicus growing in drip-irrigation enclosed site grew well, and have better water condition, higher transpiration rate and net photosynthesis rate. The diurnal changes of transpiration rate and photosynthesis rate of these two species in drip-irrigation enclosed site were single-peak curves, while that in the no-irrigation enclosed site and the natural enclosed site were double-peak curves. These two species in the later two sites had obvious siesta phenomena of photosynthesis. The water use efficiency (WUE) of these two species in the three sites was roughly the same, which indicated that the amount of drip-irrigation did not make the WUE of these two species in the drip-irrigation enclosed site lower than the value obtained under the condition of natural precipitation. In addition, C. korshinskii was more sensitive to the changes of water condition, thus when water condition is ameliorated, this species can enhance its productivity greatly. Whilst, the responses of A. mongolicus to the changes of water condition were more obtuse, thus even when water condition is improved, the productivity of this species will increase relatively less. Therefore, C. korshinskii is more suitable for the construction of planted defending vegetation with drip-irrigation, whilst A. mongolicus is more fitful for the recovery of vegetation under natural conditions.