流域生态恢复的生态学和社会学意义已获得广泛关注，但流域恢复的科学基础尚不明确，同时由于流域内环境变化的异步性，全球已实施的恢复政策大多证明是不成功的。近日，兰州大学李育团队提出了一种新的模式来验证流域生态恢复政策的正确性和有效性。相关成果发表于《科学报告》。

石羊河是我国内陆河流域中人口最密集、水资源开发利用程度最高、用水矛盾最突出、生态环境问题最严重的流域之一。为尽快遏制流域生态恶化态势，国家安排专项资金3亿元，于2007年制定和实施了《石羊河流域重点治理规划》。如何科学验证恢复政策的有效性和恢复目标的正确性，对发展流域生态恢复科学，降低环境风险，实现经济可持续发展有重要意义。

李育告诉记者，基于多时间尺度的指导思想，他们提出了一种新的模式来验证石羊河流域生态恢复政策的正确性和有效性。在千年尺度上，他们选取石羊河流域8个全新世沉积剖面，综合流域剖面孢粉结果及现代花粉传播特征，通过定义一种全新的花粉-气候指数，定量得出某三个时段流域植被带变化范围。现代时间尺度上，运用EOF方法定量分析了石羊河流域2000年-2014年夏季（6~8月）NDVI的时空变化。研究表明，该流域植被带变化模式在千年尺度和现代年际尺度呈现一致性，为验证该流域生态治理规划提供不同时间尺度的科学依据。

李育指出，现行《石羊河流域重点治理规划》的实施对上游祁连山水源涵养林区生态环境的保护和恢复起到了积极作用。该项研究为流域恢复政策的制定和流域恢复长期目标的提出提供了科学依据，对流域恢复科学发展具有重要意义。（来源：科学网 彭科峰）

Verification of watershed vegetation restoration policies, arid China

Abstract  Verification of restoration policies that have been implemented is of significance to simultaneously reduce global environmental risks while also meeting economic development goals. This paper proposed a novel method according to the idea of multiple time scales to verify ecological restoration policies in the Shiyang River drainage basin, arid China. We integrated modern pollen transport characteristics of the entire basin and pollen records from 8 Holocene sedimentary sections, and quantitatively reconstructed the millennial-scale changes of watershed vegetation zones by defining a new pollen-precipitation index. Meanwhile, Empirical Orthogonal Function method was used to quantitatively analyze spatial and temporal variations of Normalized Difference Vegetation Index in summer (June to August) of 2000–2014. By contrasting the vegetation changes that mainly controlled by millennial-scale natural ecological evolution with that under conditions of modern ecological restoration measures, we found that vegetation changes of the entire Shiyang River drainage basin are synchronous in both two time scales, and the current ecological restoration policies met the requirements of long-term restoration objectives and showed promising early results on ecological environmental restoration. Our findings present an innovative method to verify river ecological restoration policies, and also provide the scientific basis to propose future emphasizes of ecological restoration strategies.

原文链接：http://www.nature.com/articles/srep30740