新疆巴音布鲁克湿地沉积摇蚊记录对气候变化的响应

Succession of sedimentary chironomid assemblages in recent years responding to climate change in Bayinbuluk alpine wetland,Xinjiang

基于新疆巴音布鲁克高寒湿地中一碟形洼地沉积岩芯210Pb测年、摇蚊、沉积理化指标分析结果,利用冗余分析,结合气象资料,探讨了近60 a来气候变化对摇蚊演替的影响.摇蚊亚化石组合表明,从1990s开始摇蚊优势种从适应性较强的Chironomus plumosus-type向与水生植物关系密切的Dicrotendips nervosus-type、Paratanytarsus penicillatus-type转变.冗余分析结果表明总有机碳含量和粒度是影响摇蚊组合演替的主要环境因子,两者共同解释了摇蚊组合变化的31%.气候变化通过改变湿地水量平衡影响水生植被、土壤侵蚀和水体扰动,进而影响摇蚊种群演替.

The climate pattern has shifted from the warm-dry to warm-wet conditions in the arid northwestern China since 1980s. Changes in ice melting and precipitation in alpine areas caused by this climatic change can alter wetland hydrological processes, which in turn have an effect on biological habitats and ecosystem functions. Together with local instrumental data, this study inves- tigates the effect of climate change on chimnomid succession over the past 60 years using the redundancy analysis （RDA） based on sedimentary chironomid assemblages and sedimentary proxies including 210 Pb dating, total organic carbon （TOC） contents and par- ticle size, from a sediment core derived from a dish-like depression in the Bayinbuluk alpine wetland. Chironomus plumosus-type was the dominance of chironomid species before 1990s, and replaced by phytophilous including Dicrotendips nervosus-type and Pa- ratanytarsus peniciUatus-type after that years. RDA results showed that TOC contents and particle size were the most important vari- ables influencing the chironomid succession. The two factors can explain 31 percent of chironomid variations. Climatic through alte- ring the water balance which affects aquatic vegetation, water turbidity and soil erosion, can affect chironomid succession indirect- ly.