扎龙湿地植被覆盖度及其分布结构对水文气象要素的响应

扎龙湿地位于乌裕尔河尾闾，是世界上现存最大的芦苇湿地，也是丹顶鹤等珍稀鸟类重要的繁育场所和栖息地。本次研究基于遥感、气象和水文数据，通过像元二分法反演植被覆盖度，分析扎龙湿地核心区2005-2017年植被覆盖度时空分布特征，探究径流、降水和气温3项水文气象要素对湿地不同等级植被覆盖度的影响，为科学开展湿地生态需水核算和芦苇植被保护提供参考。结果表明，湿地中高植被覆盖和高植被覆盖区域主要分布于乌裕尔河来水和人工补水形成的河道及周围地区，2005-2017年，中高植被覆盖和高植被覆盖区域面积总体呈增长趋势，湿地植被生态质量整体改善。乌裕尔河来水及人工补水量对中高植被覆盖和高植被覆盖区域面积的增长起到显著促进作用，并且存在年际滞后性；温度升高有利于湿地核心区内植被覆盖度整体的提高，但促进作用并不明显；降水与湿地核心区植被覆盖无明显影响作用，乌裕尔河来水及人工补水量是影响扎龙湿地核心区植被覆盖度的主要因素。

Response of Vegetation Cover and Structure to Meteorological and Hydrologic Factors in Zhalong Wetland

The Zhalong wetland is the largest reed wetland in the world and the important breeding site and habitat of rare birds like Grus japonensis, located in lower reaches of the Wuyuer River. This paper analyzed the temporal and spatial distribution characteristics of vegetation coverage in the Zhalong Wetland core zone by dimidiate pixel model, further studied the effect of runoff, rainfall and temperature on the area proportion of different vegetation coverage based on the meteorological data and hydrologic data. The results showed that regions of medium-high vegetation cover and high vegetation cover neared the river channel created by scour of river water and diversion water. During 2005-2017, the area of medium-high vegetation cover and high vegetation cover regions were increased generally. Vegetation ecology of the Zhalong Wetland was improved. The increase of medium-high vegetation cover and high vegetation cover area was promoted by the Wuyuer River water and diversion water, as well as the promotion lags a year generally. Elevated temperature can promote vegetation cover of the entire wetland, but the acceleration is moderate. No significant influence of rainfall on vegetation cover was observed in the wetland. The runoff was the major factor that effected vegetation cover in the Zhalong Wetland. Relevant results can provide suggestions for ecological water requirement estimate and vegetation protection in the Zhalong Wetland.