Effect of water-lever regulation on species selection for ecological restoration practice in the water-level fluctuation zone of Three Gorges Reservoir
Effect of water-lever regulation on species selection for ecological restoration practice in the water-level fluctuation zone of Three Gorges Reservoir
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DOI：
10.17521/cjpe.2015.0041
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发表时间：
2015-04-01
影响因子：
--
通讯作者：
Li Zhao-Jia
中科院分区：
文献类型：
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作者：
Fan Da-Yong;Xiong Gao-Ming;Li Zhao-Jia
三峡水库消落带建成后面临着一系列生态问题。生态修复实践是解决这些问题的关键。从理论上讲，物种选择是生态恢复的关键。然而，近年来植物群落对水位消落带的适应能力的周年观测结果与淹水模拟试验结果不一致，也与短期的原位种植试验结果不一致。造成这种不一致性的原因之一是实际水位调度方案与洪水模拟试验所采用的方案在洪水节律、历时和深度上存在差异。通过对重庆忠县四年多来的实际水位的分析，发现：（1）实际水位调度与理论水位调度存在较大差异;（B）非生长季146、152、158、164、170和176 m高程的淹没天数10月至次年4月的发病率分别为294、266、223、167、101和0。在生长季节洪水期间，这些地点的洪水日数分别为68、20、11、1、0和0。海拔164米以下的场地在生长季节经常遭受内涝。目前，大多数水淹模拟试验只强调生长季的短期浅水淹没，而忽略了非生长季的深水淹没。事实上，许多研究已经证明，植物对淹水的反应在生长季节与非生长季节之间以及在深淹与浅淹之间存在着显著差异。此外，淹水模拟实验没有解释原位种间关系和群落组装。因此, 模拟淹水试验对物种筛选实践的指导意义有限。基于以上分析，建议今后的物种选择策略设计应重点关注：1）非生长季物种对消落带的适应机制; 2）释淹后物种的生长恢复、扩展和定殖; 3）对植物群落和野外生长植物的长期观测。需要认真对待对田间生长植物的长期观察。运用植物功能型方法研究消落带的物种分布、种群和群落动态以及景观格局，对消落带生态恢复实践具有重要的指导作用，是三峡库区生态研究的重要组成部分。
The water-level fluctuation zones in the Three Gorges Reservoir are facing a number of ecological problems following establishment. Ecological restoration practice is the key to solve these problems. Theoretically, species selection is critical for ecological restoration. However, the results of plant adaptation capability to the water-level fluctuation zone by yearly community observations in the past few years did not match those obtained from flooding simulation experiments, nor are they consistent with the short-term in situ planting experiments. One of the reasons leading to such inconsistency is that the practical water-level scheduling is different from the scheme adopted in the flooding simulation experiments with regards to the flooding rhythm, duration and depth. An analysis on the practical water level over four years in Zong Xian of Chongqing revealed that: a) there existed a large difference between the practical and theoretical water-level scheduling; b) the submerged days at the elevation of 146, 152, 158, 164, 170 and 176 m during the non-growing season (from October to the following April) were 294, 266, 223, 167, 101 and 0, respectively. The flooding days at those sites during the growing season flooding were 68, 20, 11, 1, 0, and 0, respectively. Sites below the elevation of 164 m suffer frequent waterlogging during the growing season. Currently, most flooding simulation experiments only emphasized the short-term shallow submergence during growing season, neglecting deep submergence during non-growing season. In fact, many studies have proven that significant differences in the responses of plants to submergence existed between the growing and non-growing seasons, as well as between deep and shallow submergence. Further, flooding simulation experiments did not account for in situ inter-specific relationship and community assembly. Accordingly, the flooding simulation experiment for species selection strategy has some shortcomings. Based on the analysis, we suggest that the species selection strategy design in the future should emphasize on: 1) the mechanisms attributing to adaptation of species to the water fluctuation zone during non-growing season; 2) the growth recovery, expansion and colonization of species following release from submergence; and 3) long-term observations on plant community and field grown plants. Long-term observations of field grown plants need to be taken seriously. Studies of species distribution, population and community dynamics, as well as landscape pattern, using plant functional type method, have an important role in guiding the ecological restoration practice in the water fluctuation zone, and are an important part of ecological research in the Three Gorges Reservoir area.