Page 178 - 《广西植物》2025年第11期
P. 178
2 1 2 2 广 西 植 物 45 卷
1 1 1 1 2ꎬ4 2
LIU Shizhang ꎬ WU Jing ꎬ CHEN Lanying ꎬ GUO Yongle ꎬ LÜ Jingya ꎬ LI Bowen ꎬ
2 1 2 2 3
ZHOU Yang ꎬ A Wang ꎬ LÜ Wangwang ꎬ SUN Jianping ꎬ LIU Yunxia ꎬ
3 5 2∗
JIA Yuefeng ꎬ BAI Ling ꎬ WANG Shiping
( 1. School of Ecology and Environmentꎬ Xizang Universityꎬ Lhasa 850000ꎬ Chinaꎻ 2. Institute of Tibetan Plateau Researchꎬ Chinese Academy
of Sciencesꎬ Beijing 100101ꎬ Chinaꎻ 3. Xizang Low Carbon Grass Animal Husbandry Technology Co.ꎬ Ltd.ꎬ Lhasa 850000ꎬ
Chinaꎻ 4. University of Chinese Academy of Sciencesꎬ Beijing 100049ꎬ Chinaꎻ 5. Xizang Autonomous
Region Agricultural Technology Popularization Service Centerꎬ Lhasa 850000ꎬ China )
Abstract: Fence enclosure is one of the primary restoration measures for degraded grasslands on the Qinghai ̄Xizang
Plateauꎬ demonstrating significant effectiveness in restoring lightly or moderately degraded grasslands but limited success
in desertified grasslandsꎬ the reasons for which remain unclear. This study focused on lightly degraded and desertified
(sand patches) alpine meadows and alpine steppes in Nagquꎬ Xizangꎬ systematically analyzing the characteristics of soil
seed banks and their relationship with aboveground vegetation in grasslands of different degradation levels inside and
outside fence. The study specifically investigated the scientific hypothesis that the poor restoration effect of fence on
desertified grasslands is related to the lack of target plant species in the soil seed bank. The results were as follows: (1)
 ̄2
The soil seed bank densities of alpine meadow and alpine steppe ranged from 184 to 2 162 seedsm and 74 to 812
 ̄2
seeds m ꎬ respectively. Notablyꎬ in alpine meadowꎬ the soil seed bank density of desertified grassland was
significantly higher than that of lightly degraded grasslandꎬ while the opposite was observed in alpine steppe. Fence
significantly increased the soil seed bank density of lightly degraded grasslands in both grassland types but had no
significant effect on desertified grasslands. The high species similarity between inside and outside fences of the soil seed
bank suggested minimal differences in species composition. (2) Overallꎬ grassland typeꎬ degradation levelꎬ and fence
had no significant impact on soil seed bank species diversity. (3) Regardless of fenceꎬ although the soil seed banks of
alpine meadow and desertified alpine steppe contained seeds of target plants beneficial for restorationꎬ but their densities
were far lower than those of weed species. ( 4) The similarity coefficients between soil seed banks and species
composition of aboveground plant communities ranged from 0.33 to 0.43 in alpine meadow and 0.22 to 0.33 in alpine
steppeꎬ both indicating low similarity and substantial differences in species composition. Thereforeꎬ this study confirms
the critical role of the soil seed bank in the restoration of desertified grasslandsꎬ with the scarcity of target plant seeds
being a key limiting factor for natural restoration of desertified grasslands. It is recommended that artificial interventionsꎬ
such as reseeding target plant speciesꎬ be implemented to enhance the ecological restoration of desertified grasslands.
Key words: fenceꎬ alpine meadowꎬ alpine steppeꎬ soil seed bankꎬ aboveground plant communityꎬ species diversityꎬ
species similarity
土壤种子库是指存在于土壤表层及深层所有 明圆等ꎬ2023)、植被类型(Wang et al.ꎬ 2020) 及退
活种子的总和ꎬ根据种子在土壤中的保留时间可 化程度对土壤种子库的影响( 赵晓男等ꎬ2020) 等
分为短暂土壤种子库(保留不超过 1 年) 和持久土 方面ꎮ 然而ꎬ关于围栏封育条件下不同类型高寒
壤种子库( 保留 1 年以上) ( Ma et al.ꎬ 2018ꎻ Chu 草地(高寒草甸与草原) 及不同退化程度( 轻度退
et al.ꎬ 2019)ꎮ 作为植物群落组成和结构维持的 化与沙化草地) 的土壤种子库特征及其与地上植
重要物质基础( Plue et al.ꎬ 2021)ꎬ土壤种子库被 物群落相似性关系的系统性研究仍然不足ꎬ这一
视为潜在的植物群落(李志强等ꎬ2010)ꎮ 近年来ꎬ 认知缺口严重限制了我们对高寒退化草地自然恢
随着气候变化和土地利用方式的剧烈改变ꎬ土壤 复潜力的准确评估和科学认知ꎮ
种子库在维持草原生态系统功能方面的重要性日 青藏高原高寒草地总面积达 150 万 km ꎬ占高
2
益凸显(Klaus et al.ꎬ 2018)ꎮ 当前ꎬ土壤种子库理 原总面积的 50%以上(Wang et al.ꎬ 2022)ꎬ其中高
论已成为恢复生态学研究的重要方向ꎬ国内外相 寒草甸和高寒草原是该区域最主要的生态系统类
关研究主要集中在放牧影响( Chu et al.ꎬ 2019ꎻ许 型(孙建等ꎬ2021)ꎮ 围栏封育作为当地广泛实施

