本文關鍵詞： 塔克拉瑪干沙漠南緣 策勒 紅柳沙包 孢粉 氣候　出處：《河北師范大學》2015年碩士論文　論文類型：學位論文

【摘要】：策勒縣位于新疆南疆塔克拉瑪干沙漠南緣中段(35°17′~39°30′N,80°03′~82°10′E,平均海拔1380m),屬于暖溫帶干旱荒漠氣候,干燥度極高,可達20.8;日照時間較長,春夏多大風,多干熱天氣,沙塵暴頻繁,植被種類組成極其貧乏,且植被群落類型單調、結構單一。本文通過對策勒縣達瑪溝地區(qū)紅柳沙包剖面的孢粉組合特征研究,利用古氣候定量重建方法(WAPLS方法),重建了研究區(qū)近400年來的氣候變化過程,并探討了植物群落的演替變化。研究結果顯示,近400年來研究區(qū)氣候和植被演化經(jīng)歷了3個主要階段和9個次一級的氣候波動。1590~1810年,是研究期內歷時最長的一次以溫暖干旱階段,但伴有次一級的冷暖和干濕交替,其中包括1590~1650年和1731~1794年的偏濕期,1651~1730年和1795~1810年的偏干期。該階段形成以蒿屬、藜科、禾本科和檉柳科等植物為主的荒漠草原植被。氣溫為10.5~13.4℃,平均12.0℃,降水量為19.7~60.1mm,平均37.4mm。當時小冰期的低溫條件和北大西洋濤動的負異常導致西風帶位置南移、強度增強,使得到達研究區(qū)的水汽產生變化,促使該階段的干旱時期相對較長。1811~1945年,是一個由暖干向冷濕的過渡期,氣候波動較大,經(jīng)歷了明顯的冷濕~冷干~冷濕~暖干的交替過程,其中1811~1838年和1859~1909年為兩個冷濕期,1839~1858年,為一個冷干期;1910~1945年,是一個偏暖干期。本階段植被條件有所改善,形成以檉柳、藜科等植物為主的荒漠灌叢植被,年平均氣溫為9.8~13.4℃,平均10.9℃,降水量為19.7~83.8mm,平均54.3mm;1946~2010年,氣溫小幅度下降,降水量明顯增多,進入一個相對冷濕階段,年均溫為9.5~12.2℃,平均10.3℃,降水量為37.8~98.5mm,平均68.9mm。植被類型仍以荒漠灌叢為主。孢粉組合中出現(xiàn)大量以大禾本為主的農作物孢粉,人類活動對研究區(qū)氣候環(huán)境影響逐漸增大。20世紀30年代以來,人工綠洲面積迅速擴大,明顯的“綠洲效應”使區(qū)域氣溫小幅度下降,降水持續(xù)增加;20世紀70年代以后,降水呈現(xiàn)下降趨勢。
[Abstract]:Cele County is located in the middle section of the southern edge of Taklimakan Desert in southern Xinjiang, with an average altitude of 1380mg. It is a warm temperate arid desert climate with a high degree of dryness of 20.8.The sunshine time is longer, the spring and summer are windy, the dry and hot weather is more dry and hot, and the sandstorm is frequent. The vegetation species composition is extremely poor, and the vegetation community type is monotonous and the structure is single. This paper studies the sporopollen assemblage characteristics of Hongliu Shabao section in Damagou area, Cele County, China. The paleoclimate quantitative reconstruction method WAPLS method was used to reconstruct the climate change process in the past 400 years in the study area, and the succession changes of plant communities were discussed. In the past 400 years, the climate and vegetation evolution in the study area has experienced three main stages and nine sub-level climatic fluctuations .1590 ~ 1810, which is the longest warm and arid stage in the study period, but accompanied by sub-level cold and warm, dry and wet alternations. It includes the dry periods of 1651 ~ 1730 and 1795 ~ 1730 in the wet period from 1590 to 1650 and from 1731 to 1794. The desert steppe vegetation is formed in this stage, which is dominated by Artemisia, Chenopodiaceae, Gramineae and Tamariaceae. The temperature is 10.50.13.4 鈩，

本文編號：1555991