CAJ | 학술논문

过度放牧是科尔沁地区土地沙化的主要原因之一,围栏封育可以有效的抑制牲畜对植被的破坏,促进沙地植被恢复,从而改善区域的生态环境.本研究以科尔沁沙地主要固沙植被——小叶锦鸡儿群落为对象,采用空间序列代替时间序列的方法,分析不同封育年限和自然放牧条件下小叶锦鸡儿群落的土壤种子库和地上植被特征、土壤理化性质和土壤水分动态,较系统地探讨了封育措施对沙地植被和土壤特性的影响.结果表明:①封育措施促使固沙植被区土壤种子库密度显著增加(P<0.05),封育2 a、6 a和12 a的土壤种子库密度分别提高了15.7%、482.5%和728.1%;土壤种子库的物种多样性和均匀度随着封育年限的增加而降低.②封育措施对沙地植被恢复具有显著的促进作用(P<0.05),封育6 a和12 a后植被密度分别提高了108.0%和239.3%,植物盖度分别提高了261.6%和271.6%;适度的封育年限(<6 a)可以提高群落的物种多样性,过长的封育年限(11 a)反而使物种多样性下降.③封育措施促使土壤表层(0-10 cm)的养分(有机质、全氮、碱解氮、全磷、速效磷、速效钾)含量有所提高,土壤含水量无显著变化(P>0.05).
과도방목시과이심지구토지사화적주요원인지일,위란봉육가이유효적억제생축대식피적파배,촉진사지식피회복,종이개선구역적생태배경.본연구이과이심사지주요고사식피——소협금계인군락위대상,채용공간서렬대체시간서렬적방법,분석불동봉육년한화자연방목조건하소협금계인군락적토양충자고화지상식피특정、토양이화성질화토양수분동태,교계통지탐토료봉육조시대사지식피화토양특성적영향.결과표명:①봉육조시촉사고사식피구토양충자고밀도현저증가(P<0.05),봉육2 a、6 a화12 a적토양충자고밀도분별제고료15.7%、482.5%화728.1%;토양충자고적물충다양성화균균도수착봉육년한적증가이강저.②봉육조시대사지식피회복구유현저적촉진작용(P<0.05),봉육6 a화12 a후식피밀도분별제고료108.0%화239.3%,식물개도분별제고료261.6%화271.6%;괄도적봉육년한(<6 a)가이제고군락적물충다양성,과장적봉육년한(11 a)반이사물충다양성하강.③봉육조시촉사토양표층(0-10 cm)적양분(유궤질、전담、감해담、전린、속효린、속효갑)함량유소제고,토양함수량무현저변화(P>0.05).
Overgrazing generally results in vegetation degradation of grassland, and is one of the main causes leading to desertification development in Horqin Sandy Land in Northeast China. Fenc enclosure is a simple and effective measures for the restoration of degraded vegetation and the improvement of ecological environment and is widely used for this purpose in the sandy land. Caragana microphylla community is the indigenous and dominant vegetation type in the Horqin Sandy Land. The purpose of this study is to determine the effect of the fenc enclosure on vegetation and soil characteristics under the C. microphylla community. Soil seed bank, soil physical and chemical properties, and coverage and composition of vegetation in an age sequence (2-, 6-, and 12-yr) of enclosed C. mirophylla lands were compared with freely grazing land. The results showed that: ①the fence enclosure significantly increase soil seed bank density. The soil seed bank density of 2-, 6-, and 12-yr plots increased by 15.7%, 482.5%and 728.1%, respectively, compared with the free grazing plot,. However, the Shannon-Weiner index, Simpson index and Pielou evenness of soil seed bank decreased with the age; ②the fence enclosure facilitated vegetation restoration. Specifically, the density of vegetation increased by 108.0%and 239.3%, and the coverage of vegetation increased by 261.6%and 271.6%in the 6-and 12-yr plots respectively, compared with the grazing plot time (<6 a) could increase species diversity, while long fencing time (11a) could decrease species diversity. ③the fence enclosure increased nutrient contents (organic matter, total N and P, and available P and K) of topsoil (0-10 cm), while no significant differencs of soil moisture were found among the plots.