新疆克亚克库都克唐代烽燧遗址木炭记录的薪材利用和植被生态

FUEL WOOD UTlLIZATION AND VEGETATION ECOLOGY AT THE KEYAKEKUDUKE WATCHTOWER SITE OF TANG DYNASTY IN YULI COUNTY,XINJIANG—INFERRED FROM CHARCOAL RECORDS

考古遗址中的木炭遗存是重建过去局地木本植被群落组成、植物多样性、景观生态格局以及探索人地关系的关键生物指标之一。对于具有特殊性质的烽燧遗址,木炭是一种用以解读可能与烽烟传递军情、戍守人员生活用火密切相关的特定薪材的地质档案。文章对新疆尉犁克亚克库都克唐代烽燧遗址出土的大量木炭样品进行筛选、鉴定和定量分析,以了解驻防先民对烽燧薪材的选择,重建当地的植被生态和景观。木炭显微结构观察结果及树种数量百分比统计显示,有4种木材被选作薪材,包括数量百分比最高的柽柳属(Tamarix sp.)(83.63%)和数量百分比较低的杨属(Populus sp.)(11.95%)、柳属(Salix sp.)(3.54%),以及驼绒藜属(Krascheninnikovia sp.)(0.88%)。基于"最省力原则"和木炭化石组合中树木种属含量与现今当地林地中的丰度和多度成对应比例关系等理论,推断该军事遗址附近为以柽柳属为优势种,其他木本植物为伴生种的植物群落结构。这与现今在塔里木盆地东北部边缘河流沿岸典型的植被类型分布特征相似,由此进一步指示当时先民生存的地表景观为沿河绿洲。

The Keyakekuduke watchtower( 41° 05’31″N,87° 16’13″E) is situated on the east edge of the Tarim Basin in Yuli County,Xinjiang. It is located on the north bank of the middle reaches of the Kongqi River,which flows eastwards into the Lop Nor. The extremely dry climate in this region allows for excellent preservation of organic remains. The age of the construction and occupation of the watchtower occurred during the Tang Dynasty( 618 ~907 A.D.). It belonged to a grass-roots military management organization on the “Loulan”Road,which was a vital branch of the Silk Road. The site consists of two parts: a watchtower and the living quarters for soldiers. Five ash piles,named HD1 ~ HD5,were cleared around the tower;these piles were mainly formed by the accumulation of garbage from ancient resident households.For watchtowers with special properties,charcoal is a geological archive to interpret specific fuelwood that may be closely related to the timely transmission of military information and living activities. In this paper,226 charcoal fragments > 4 mm excavated from the HD1 of the Keyakekuduke watchtower were identified,and quantitatively analyzed. The anatomical features of the three sections of charcoal fossils were observed by Stereo microscope and SEM. Wood anatomy atlases were used for the identification.The results show that four taxa were selected as fuelwood,including Tamarix sp.( 83. 63%),Populus sp.( 11. 95%),Salix sp.( 3. 54%) and Krascheninnikovia sp.( 0. 88%). It suggests that Tamarix sp. was the most exploited woody plant for fuel in this area. Considering the inconvenience of transportation at that time,these branches for fuelwood should be collected around the site by the ancients. In view of the limited types of local vegetation,these woods were used as fuel for beacon-fire and domestic fire simultaneously.Based on the theories of “Principle of Least Effort ” and the concordance between composition of fossil charcoals and abundance as well as richness of tree species in modern local woodland,it can be inferred that the plant community near this military site is dominated by Tamarix sp.,with other woody plants as the auxiliary species. Today,Tamarix sp. and Populus sp. constitute the desert riparian forest landscape in Tarim Basin. As a kind of hygrophilous plant which is not common in this region,the existence of Salix sp. indicates that there might be a water source in the vicinity of the beacon tower. The result of the environment reconstruction of this site is similar to the typical vegetation distribution pattern along the rivers in the northeastern margin of Tarim Basin today,which further indicates that the surface landscape of the ancestors at that time was the oasis along the river.