干旱区生态环境知识资源中心(Arid): 荒漠草原土壤种子库对灌丛引入和降水梯度的响应特征

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	荒漠草原土壤种子库对灌丛引入和降水梯度的响应特征
其他题名	Responses of the soil seed bank to simulated rainfall levels and anthropogenically introduced shrub encroachment in the desert steppe
	于露 1; 周玉蓉 1; 赵亚楠 1; 郭天斗 1; 孙忠超 1; 王红梅 2
来源期刊	草业学报
ISSN	1004-5759
出版年	2020
卷号	29 期号:4 页码:41-50
中文摘要	为了揭示宁夏荒漠草原土壤种子库对灌丛引入过程及降水的响应特征,采用室内萌发法和野外水分激发法,对宁夏荒漠草原封育草地、放牧地、不同年限(3、12、22yr)和间距(40、6、2m)柠条灌丛地开展草地-放牧-灌丛引入过程的土壤种子库萌发及其对不同降水梯度(-60%,-40%,-20%,0,20%,40%)响应特征进行了研究。结果如下:不同年限、间距引入灌丛地0~200 cm年平均土壤水分含量显著低于封育草地和放牧地(P<0.05),随着灌丛年限和密度增加,加剧深层土壤水分的消耗,土壤旱化加重,使得灌丛地无明显春季返潮期,土壤水分仅为8.14%、8.83%,分别显著低于同期封育草地和放牧地16.00%、13.00%,在这样的水土条件下不同年限、间距灌丛地室内萌发下的0~10 cm土壤种子库密度分别为6186和5831粒·m~(-2),分别高于封育草地、放牧地2965、2065粒·m~(-2)(P<0.05)。各样地主要集中于0~5 cm土层,占萌发总数70.04%,且均以一年生猪毛蒿萌发为主,高达87.12%~96.55%,并随灌丛年限和密度的增大而增加,而多年生草本萌发种类仅为5种;不同降水梯度野外激发下的不同年限、间距灌丛地种子萌发平均数量为855和640粒·m~(-2),以降水量+20%时所激发土壤种子库萌发密度最高,分别为2266和1600粒·m~(-2),一年生与多年生草本种子库萌发密度和种类均随降水量升高而增加,且均在降水梯度最大时(+40%)呈下降趋势,而且相较于多年生草本,一年生草本在不同灌丛地萌发率高达90.58%~ 100.00%,显著高于放牧地或封育地(P<0.05),在灌丛引入过程中对土壤干旱和降水变化表现得更为敏感和适应。
英文摘要	This study explored the responses of the soil seed bank(0-5 and 5-10 cm soil depths sampled)to variation in precipitation and to encroachment by anthropogenically introduced shrubs(Caragana)in desert steppe grassland in Yanchi County,Ningxia Province.Simulated rainfall levels relative to mean annual precipitation of 290 mm (-60%,-40%,-20%,0,20%,40%)were generated for eight otherwise similar sites with different vegetation categories:grassland fenced to preclude grazing(FY),grazed grassland(FM),and grassland with introduced shrubs established for 3,12,or 22 years(3 sites,PY3,PY12,PY22)or at planting distances of 2,6,or 40m (3 sites,PS2,PS6,PS40).Species represented in the seedbank and their numbers were determined using germination counts after incubation of sampled soil in the field and in the greenhouse.A major finding was that in grassland with introduced shrubs,soil moisture for 0-200 cm soil depth was 8.14% when averaged across seasons and over PY sites,and 8.83% when averaged over PS sites,which was significantly lower(P<0.05)than corresponding values for FY and FM sites(16.00%and 13.00%,respectively).PS and PY sites also did not show higher soil moisture levels in spring than in autumn that were seen in FY and FM plots,and the soil moisture reduction at 40m spacing was about 50%of that at 6 and 2mshrub spacing.The number of species detected in the soil seed bank in field germination tests at the eight sites ranged between 4 and 7,comprising annual herbs,perennial herbs and shrubs,with total counts of 2965·m~(-2) and 2065·m~(-2),respectively,for FY and FM sites;6198,6465 and 5897·m~(-2),respectively,for PY3,PY12 and PY22 sites;and 3898,5897 and 7698·m~(-2),respectively,for PS40,PS6 and PS2 sites.Of the total seed bank germination counts across the eight sites,89.6% (range 87.12%to 96.55%)belonged to the annual herb Artemisia scoparia,and 70.04%came from the 0-5 cm soil layer.The number of species detected in glasshouse pot germination tests at different simulated rainfall levels,for samples from the eight sites,ranged between 1 and 5.For soil samples from all eight sites,the highest numbers of germinated seeds occurred in the+20%rainfall treatments and the lowest in the-60%treatment,while the+40%treatment was usually second lowest.For FY and FM sites the germinated seed density of the+20%treatment was 533 and 233·m~(-2),respectively.For sites with introduced shrubs,peak germination was 2266·m~(-2) and 1600·m~(-2) averaged over PY and PS sites,respectively.In summary,at these sites,introduced Caraganashrubs depleted soil moisture at depth,and the soil moisture reduction increased the dominance in the seedbank of the annual herb Artemisia scoparia,and tended to reduce species richness of the seedbank.
中文关键词	荒漠草原 ; 人工灌丛 ; 土壤种子库 ; 土壤水分
英文关键词	desert grassland anthropogenic introduced shrub soil seed bank soil moisture
语种	中文
收录类别	CSCD
WOS类目	AGRICULTURE MULTIDISCIPLINARY
WOS研究方向	Agriculture
CSCD记录号	CSCD:6689695
来源机构	宁夏大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/318358
作者单位	1.宁夏大学农学院, 银川, 宁夏 750021, 中国; 2.宁夏大学农学院;;西北退化生态系统恢复与重建教育部重点实验室, ;;西北退化生态系统恢复与重建教育部重点实验室, 银川;;银川, 宁夏;;宁夏 750021;;750021, 中国
推荐引用方式 GB/T 7714	于露,周玉蓉,赵亚楠,等. 荒漠草原土壤种子库对灌丛引入和降水梯度的响应特征[J]. 宁夏大学,2020,29(4):41-50.
APA	于露,周玉蓉,赵亚楠,郭天斗,孙忠超,&王红梅.(2020).荒漠草原土壤种子库对灌丛引入和降水梯度的响应特征.草业学报,29(4),41-50.
MLA	于露,et al."荒漠草原土壤种子库对灌丛引入和降水梯度的响应特征".草业学报 29.4(2020):41-50.