CAJ | 학술논문

【目的】研究流动沙丘与丘间低地过渡带的生态过程，探讨过渡带的时空格局及其对流动沙丘－植被面积的关系的调控作用。【方法】在科尔沁沙地西部乌兰敖都地区，利用样带法在所选择的流动沙丘背风坡迎风坡与丘间低地的连接处，测量沙埋高度、宽度以及风蚀深度，并在生长季末调查样方内植物的丰富度和多度。【结果】1)流动沙丘背风坡在风力作用下，沙子埋压丘间低地植被，导致部分沼泽－草甸植物退出丘间低地；沙丘迎风坡底部的裸沙带，每年生长季初有沙丘先锋植物侵入，在生长季末形成建植种群，最终形成迎风坡过渡带。迎风坡过渡带的宽度为3～5 m，背风坡过渡带的宽度为4～6 m，因此，流动沙丘与丘间低地过渡带属于小尺度过渡带。2)流动沙丘背风坡－丘间低地过渡带的宽度与丘间低地面积及其垂直风向宽度都呈显著负相关(P ＜0.05)，而迎风坡过渡带的相关性不显著(P＞0.05)，但与丘间低地植被扩展宽度呈显著正相关(P ＜0.05)。3)流动沙丘区的植被覆盖面积呈增加趋势。4)面积大于5 hm2的丘间低地，垂直风向宽度大，且植被密度大、植株高，容易形成风障，降低风速，致使背风坡沙埋速度慢，而且迎风坡植物入侵速度快，导致丘间低地植被宽度和面积增加。【结论】在自然条件下，流动沙丘区的植被恢复开始于迎风坡过渡带；迎风坡过渡带和背风坡过渡带的权衡直接调控丘间低地植被的覆盖面积和格局。另外，大面积的丘间低地对于流动沙丘区的植被恢复具有重要作用。
【목적】연구류동사구여구간저지과도대적생태과정，탐토과도대적시공격국급기대류동사구－식피면적적관계적조공작용。【방법】재과이심사지서부오란오도지구，이용양대법재소선택적류동사구배풍파영풍파여구간저지적련접처，측량사매고도、관도이급풍식심도，병재생장계말조사양방내식물적봉부도화다도。【결과】1)류동사구배풍파재풍력작용하，사자매압구간저지식피，도치부분소택－초전식물퇴출구간저지；사구영풍파저부적라사대，매년생장계초유사구선봉식물침입，재생장계말형성건식충군，최종형성영풍파과도대。영풍파과도대적관도위3～5 m，배풍파과도대적관도위4～6 m，인차，류동사구여구간저지과도대속우소척도과도대。2)류동사구배풍파－구간저지과도대적관도여구간저지면적급기수직풍향관도도정현저부상관(P ＜0.05)，이영풍파과도대적상관성불현저(P＞0.05)，단여구간저지식피확전관도정현저정상관(P ＜0.05)。3)류동사구구적식피복개면적정증가추세。4)면적대우5 hm2적구간저지，수직풍향관도대，차식피밀도대、식주고，용역형성풍장，강저풍속，치사배풍파사매속도만，이차영풍파식물입침속도쾌，도치구간저지식피관도화면적증가。【결론】재자연조건하，류동사구구적식피회복개시우영풍파과도대；영풍파과도대화배풍파과도대적권형직접조공구간저지식피적복개면적화격국。령외，대면적적구간저지대우류동사구구적식피회복구유중요작용。
Objective]In active dune fields,the transition zones between active dunes and interdune lowlands,which have high temporal and spatial heterogeneity and complex ecological processes,can indicate or coordinate the relative relationship between vegetation and sand dune and regulate the area and structure of vegetation in the whole active sand dunes. In the last few decades,much attention has been paid to the vegetation processes in active sand dunes or interdune lowlands,while researches on how vegetation establishes and develops in transition zones between active dunes and dune slacks are still scarce. Most of all,study on temporal and spatial patterns,vegetation composition,plant adaptation mechanism and the restrictive factors in transition zones between active dune and interdune lowland is not still reported.[Method]In this paper,by means of the belt transect method in the field investigation,we measured the height and width of sand burial on leeward slopes of active sand dunes as well as the depth of wind erosion on windward slopes of active sand dunes at Wulanaodu region,the western Horqin Sandy Land,and examined the plant richness and abundance in the quadrats by the end of growing seasons. We especially investigated the effects of transition zone dynamics on vegetation areas and patterns in interdune lowlands. Through this study,we aim at answering two questions that how aeolian erosion and sand burial influence the temporal and spatial patterns of the transition zones between active dunes and interdune lowlands and that how the transition zone dynamics affect vegetation areas and patterns in whole active dune fields.[Result]The result showed that (1) part of Limnocryptophyte-meadow and Steppe species in interdune lowlands retreated from the transition zones in leeward slopes and part of pioneer vegetative propagation was dominant in frequency and density in the transition zones of windward slopes due to the dynamic changes of the transition zone between active dune and interdune lowland. The width of the transition zones on leeward slopes was 4 -6 m,and the width of the transition zones on windward slopes was 3 -5 m,indicating that the transition zones belonged to fine-scale ones. The transition zones on leeward slopes formed in late May,and the ones on windward slopes formed in late September. (2) There were significant and positive ( P﹤0 . 05 ) correlations between the widths of transition zones from leeward slopes of active sand dunes to interdune lowlands and the areas of interdune lowlands or the perpendicular widths to the wind direction; the the widths of transition zones from windward slopes of active sand dunes to interdune lowlands were not significantly ( P﹥0 . 05 ) correlated with the areas of interdune lowlands or the perpendicular widths to the wind direction ,but was significantly and positively (P﹤0. 05) correlated with the widths of increased vegetation of interdune lowlands. (3) In the active sand dune field,the vegetation-covered areas had an increasing trend. (4) In the large area (﹥5 hm2 ) of the interdune lowland,the width of the vertical wind direction was large,and vegetation had high density and was high,and thus was able to form large-area windbreaks and lower wind speeds,leading to low speeds of sand burial in the leeward slope and rapid speeds of plant invasion in the windward slope,hence,increase the vegetation width and area in the interdune lowlands of active sand dune fields. [Conclusion]This study indicated that in natural conditions,vegetation restoration of active sand dune fields generally commences with revegetation of transition zones between windward slopes of active sand dunes and interdune lowlands; and the interdune lowlands of large area play an important role during vegetation restoration of active sand dune fields.