半干旱矿区侵蚀营力对黑沙蒿根系生长特性的影响及其自修复

以半干旱矿区典型分布的黑沙蒿为研究对象，通过野外原位不离体试验，模拟侵蚀拉拔破坏对黑沙蒿根系生长特性的影响，并分析其受损自修复能力，旨在揭示植物根系在脆弱生态区中抵御外力侵蚀的生存策略。结果表明，拉拔破坏形成机械损伤后，根系生长速率和活性均明显降低，持续拉拔对二者的抑制作用显著大于瞬时拉拔，重度损伤产生的负反馈显著大于轻度损伤。黑沙蒿根系在拉拔破坏后，会出现大量死亡的现象，造成活根数量锐减，瞬时和持续拉拔分别可造成活根减少60.6%和66.9%,轻度和重度损伤后活根分别减少59.7%和67.8%。黑沙蒿根系生长速率和活性修复率均随修复时间的推移而逐渐增大，但自修复能力有限，无法有效消除侵蚀破坏造成的负反馈，生长修复率平均仅为56.8%,活性修复率为70.5%。综上所述，在侵蚀多发区进行植被恢复时，应充分考虑植物根系应对外力破坏时的生长特性和受损自修复能力，以保证植物对逆境的适应并发挥有效固土抗蚀等生态功能。

Effects of erosive agent on root growth and self-healing of Artemisia ordosica in semi-arid mining site

To reveal plant root strategies against external erosion in ecologically fragile zones, we conducted an in situ simulation field experiment to examine the effects of drawing damage on root growth of Artemisia ordosica in semi-arid mining site, and analyzed the self-healing ability of root after erosion. The results showed that the relative growth rate and activity of roots were significantly decreased after being damaged by drawing. The negative effects of persistent drawing on growth rate and activity were significantly greater than that of instantaneous drawing, and that of severe damage was significantly greater than mild damage. A. ordosica roots would die when mechanical damage formed after drawing damage, resulting in higher reduction rate of living root numbers than that of the control. Instantaneous and persistent drawing resulted in a reduction of 60.6% and 66.9% of live roots, respectively. The number of live roots was decreased by 59.7% and 67.8% after mild and severe damage, respectively. After drawing damage, the relative growth rate and activity-repairing rate of A. ordosica roots gradually increased with repair time. Due to the limited self-healing ability, negative impacts caused by erosion damage could not be effectively eliminated. The average repair rate of growth was 56.8%, while the repair rate of activity was 70.5%. In conclusion, the growth characteristics and self-healing ability of roots should be fully considered during vegetation restoration in the frequently eroded areas, in order to ensure the adaptation of plants to the adverse environment and their role in ecological functions such as soil stabilization and erosion resistance.