首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
通过研究金安桥水电站废弃渣场种子库和周边群落种子库以及渣场地面和周边群落地面植被的变化特征,结果表明:①周边群落土壤种子库和地面植物的物种丰富度大于渣场,从地面与种子库的物种组成分析得出,渣场植被恢复正处于由一年生草本植物向多年生草本植物过渡的阶段;②周边群落地面植物与土壤种子库的物种丰富度(30,33)及数量(186,1962),渣场地面植物与土壤种子库的物种丰富度(10,12)及数量(35,1784);③由于植物种子寿命短,加之土壤环境差,导致周边群落地面植物与种子库相似度(0.09)和渣场地面植物与种子库的相似度(0)差异性大。  相似文献   

2.
Desertification in degraded grasslands is manifested through the development of bare sandy patches, which eventually lead to habitat fragmentation. The ability of these bare sandy patches to regenerate naturally through in-situ soil seed banks is not well understood. To fill this knowledge gap, we randomly selected 24 bare sandy patches with areas ranging from 19 to 898 m2 in a desertified grassland of the Horqin sandy land, Northern China to determine whether soil seed bank can be used for natural regeneration of bare sandy patches. Species composition and density of soil seed bank as well as aboveground vegetation composition, abundance and coverage were investigated. We then determined their relationships with in-situ habitat characteristics. Our observations showed that the studied area had low soil seed bank density and species richness, as well as depauperate soil seed bank communities. Consequently, local soil seed bank was not able to provide sufficient seed source for natural regeneration. This was indicated by the relationships between aboveground vegetation, soil seed bank and the in-situ habitat characteristics. For bare patches with an area between 300 m2 and 900 m2, increase the soil seed bank density and species richness should be the main restoration measures. For bare patches with a small area of less than 50 m2, restoration of vegetation density should be the main measure. Our data highlighted that different extents of desertification, indicated by different bare patches, are requiring distinct restoration measures.  相似文献   

3.
汶川地震不同次生地质灾害类型区土壤种子库特征   总被引:1,自引:0,他引:1  
为了解地震后次生地质灾害土壤种子库特征及其植被恢复特点,在四川省北川县采用野外取样和在当地自然环境下萌发相结合的办法,研究了5种不同灾害类型(包括滑坡、崩塌、泥石流、落石及堰塞湖)土壤种子库大小、物种组成及其与地上植被之间的关系。研究结果表明,不同灾害类型土壤种子库密度介于30133.33±6776.03~93383.33±26499.81粒/m2方差分析显示,只有落石损毁类型种子库密度与其它几种灾害类型差异显著,各灾害类型土壤种子库种子密度在0-5cm和5-10cm土层之间无明显分层区别。土壤种子库中一年生和多年生草本所占比例为90.48%,灌木所占比例为9.52%,没有观察到乔木种。各土壤种子库之间Sorensen相似性指数较高,为0.529~0.714土壤种子库与相应样地地上植物之间相似性不高,相关性也不密切,其相似性指数介于0.167~0.292。建议灾害损毁地植被恢复以自然恢复为主,若采取简易的水土保持措施和适量客土措施,将会促进种子的萌发和植被的更新种子库中缺乏乔木种,快速乔木化需要人工输入种子雨。  相似文献   

4.
[目的]对黄土丘陵沟壑区红砂灌丛植被土壤种子库的特征及红砂灌丛植被自然更新潜力进行分析和评估,以说明红砂灌丛土壤种子库在植被恢复与重建中的重要作用。[方法]采用土壤种子库"萌发法"(每个地段10个2m×2m样方内分表土层0—2cm和2—5cm土层采集土样)及野外植被调查方法,对黄土丘陵沟壑不同坡位红砂灌丛土壤种子库进行研究。[结果]黄土丘陵沟壑区红砂灌丛植被土壤种子库发芽试验共观察到的4 251株幼苗,分属于9个物种。土壤种子库密度在100~1 000粒/m2,物种数在0.8~1.2种/0.01m2,下坡段的土壤种子库平均种子密度和平均物种数均比上坡段高。3个坡段的2个层次的平均种子密度和平均物种数均随土层加深而减小。3个坡段土壤种子库和地上植被的组成物种多为草本植物和红砂灌丛,地上植被与其土壤种子库的密度及物种数均呈不显著相关;物种组成的Sorensen相似性指数较高,均达到0.60以上,且土壤种子库比地上植被具有更高的物种丰富度。[结论]黄土丘陵沟壑区红砂灌丛具有依靠土壤种子库实现自然更新的潜力,但由于物种组成种类较少,现存灌丛植被一旦遭到破坏,仅靠土壤种子库恢复现存植被是困难的,需要在对自然恢复潜力评估的基础上,积极采取人工保护促进自然恢复的策略。  相似文献   

5.
风沙黄土区排土场作为一种人造生态系统,自然条件恶劣,土壤贫瘠,植被恢复困难。为了探明有效的人工促进植被恢复措施,采用植被调查与种子库萌发试验相结合的方法,通过研究不同植被类型地上植物群落与土壤种子库特征及二者的关系,探讨了其植被恢复效益及潜力。结果表明:研究区人工植被恢复下地上植物群落中共47种植物,分属16科40属,土壤种子库共14种植物,分属5科13属,其中均以禾本科、菊科、藜科、豆科占主导地位; 灌木植被的地上植被和土壤种子库的物种多样性均表现为最优; 地上植被与土壤种子库密度的变化范围为88.48~495.47株/m2,74.74~1422.91粒/m2,且均在草地类型下最大。土壤种子库和地上植被的相似性普遍较低,相似性系数仅为0.16~0.23。因此,风沙黄土区排土场的植被恢复与重建需要加强保护与管理,可以考虑构建以草灌配置为主的人工植被恢复模式,保障群落的恢复潜力,并提高群落多样性与稳定性,亦可考虑引入外源种子库提升群落恢复的潜力。  相似文献   

6.
为了解汶川地震灾区典型区不同植被类型土壤种子库特征及其与灾害受损程度间的关系,采用野外调查取样和室内试验相结合的方法,研究了北川县苏保河与魏家沟流域4种植被类型(未受损林地、受损林地、灾后恢复草地和灾后裸地)土壤种子库的物种组成、种子密度、多样性及其与地上植物群落的关系。结果表明:4种植被类型样地中,土壤种子库密度为212.5~1 758.3个·m-2,每样带(200 m2)平均物种数为4.3~14.7个。4种植被类型土壤种子库的组成物种多为多年生或一年生草本植物,土壤种子库与相应地上植被的物种数仅受损林地与灾后恢复草地中呈显著相关;物种组成的Sorensen相似指数除裸地低于0.250外,其余均高于0.250。基于以上分析结果,在灾区进行植被恢复,需要考虑次生灾害对植被的持续破坏可能性,采用工程措施及人为引种的方式增加成活率和延续性。  相似文献   

7.
The similarity in species composition and abundance between the soil seed bank and its associated vegetation was studied in six vegetation units of the Strandveld Succulent Karoo, South Africa. A total of 103 taxa were recorded in the vegetation, of which 34 taxa were also present in the seed bank. Five taxa were unique to the soil seed bank. In general, the taxa most abundant in the vegetation were also recorded in the seed bank and vice versa. Mean seed bank density varied between different plant types. Perennial taxa were most abundant in the vegetation, while annual taxa were most abundant in the seed bank. Annual taxa (excluding grasses) yielded the highest similarity between vegetation and seed bank (67ċ9 per cent), while that of perennial (excluding grasses) and grass taxa were 34ċ2 per cent and 40ċ0 per cent respectively. An overall similarity of 47ċ0 per cent between the seed bank and its associated vegetation was obtained for this part of the Strandveld Succulent Karoo. The seed bank of the study site will be a good source of future annual vegetation, but not of perennial vegetation. Topsoil replacement, sowing and transplanting of selected species will be essential for the success of post‐mining revegetation efforts following complete destruction of the existing vegetation. Annual species may be recruited from the soil stored seed bank, while many perennial species will have to be reintroduced by means of sowing and/or transplanting. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

8.
以六盘山森林植被为研究对象,通过20多年的森林土壤种子库变化与植被演替过程的试验研究,分析了8种森林群落类型的不同生长年限、生长坡位、枯枝落叶层和土壤深度对土壤种子库形成过程的影响。结果表明:六盘山森林群落不同生长坡位,土壤种子库的储量坡中部>坡下部>坡上部;不同层次土壤种子库,枯枝落叶层远高于0-15 cm深土层,8种森林群落类型排序为华北落叶松林>油松林>华山松林>辽东栎林>山杨林>白桦林>灌丛>草地;土壤种子库储量高峰期,不同群落有显著差异,华山松林和油松林在林龄的30~40年,华北落叶松林在20年,辽东栎林、山杨林、白桦林在15~20年,灌丛和草地在10~20年,其森林群落生长年限与土壤种子库储量变化趋势呈拟合曲线,符合指数方程,相关性极为显著;土壤种子库物种组成丰富,草本和灌木植物远高于乔木树种,乔木树种仅有3~5种,但多数为外来入侵种,而在每一类型中出现频率最高的草地植物多为蒿类,灌木植物为柔毛绣线菊和沙棘,乔木为辽东栎树种。因此,在六盘山林区植被自然更新与合理演替的驱动种和先锋种草地植物为蒿类,灌木植物为柔毛绣线菊和沙棘,乔木为辽东栎,其次是华北落叶松、油松和华山松。  相似文献   

9.
Plant invaders may directly or indirectly affect ecosystem resilience through their impact on soil seed banks. The invaders, and the application of control measures, change seed bank dynamics by altering the number of seeds entering and leaving the seed bank. We tested the impact of bitou bush (Chrysanthemoides monilifera ssp. rotundata), on the seed bank. We examined seed banks in heavily-invaded, sparsely-invaded and managed dunes, where bitou bush biomass had been controlled. While management of bitou bush may have reduced the density of bitou bush seeds in the soil, it did not reduce the richness of other weed species. Native tree species richness was significantly higher in seed banks of sparsely-invaded than either heavily-invaded or managed sites, perhaps indicating a permanent shift in community structure following invasion. However, remaining indices of native seed bank diversity were similar across all invasion categories, indicating that seed banks of many native species were unaffected by both invasion and management. While examination of seed banks is informative in assessing past and potential community dynamics, low similarity between the standing vegetation and seed bank at all sites indicated that many hind dune species had other storage or regeneration modes and seed banks cannot be relied upon for comprehensive dune restoration.  相似文献   

10.
坝上草原退耕地植被不同恢复处理土壤种子库研究   总被引:1,自引:1,他引:1  
采用野外调查取样和室内实验相结合的方法,研究坝上草原退耕地土壤种子库的物种组成、密度和物种多样性等特征.结果表明:自然恢复、浅耕处理和深耕处理3种不同恢复措施下,土壤种子库物种丰富度(种)大小为浅耕处理(18)>自然恢复(15)>深耕处理(14);自然恢复处理、浅耕处理和深耕处理土壤种子库密度分别为23 949粒·m-2、15746粒·m-2和10600粒·m-2,浅耕处理和深耕处理分别比自然恢复处理减少34.3%和55.7%;不同恢复方式下土壤种子库与地上植被的物种密度的对应关系可用三次曲线来表示.土壤种子库间有较高的相似系数,但随着干扰程度的增加而减少.  相似文献   

11.
The effects of pollution on thecomposition of soil seed banks in four drained pinemires located along a pollution gradient in southernFinland were studied using the emergence method. Thespecies composition of the seed bank was compared withthe above ground vegetation. Dominant species in theseed banks were Calluna vulgaris, Betulaspp. and Ledum palustre. Seeds seemed to beviable despite a heavy pollution load. Especially inthe vicinity of the pollution source, seed bank andabove ground vegetation were weakly correlated.  相似文献   

12.
In the attempt to ensure long-term-conservation of flood meadows along the northern Upper Rhine transfer of seed-containing plant material was successfully applied since 2000. In this highly dynamic habitat, many typical plant species rely on a persistent seed bank for re-establishment after disturbance. But in contrast to the re-established above ground vegetation, seed bank composition remains unknown. Thus the main aims of the study were to elucidate the current seed bank composition and to assess patterns of seed and species traits. To this end we sampled above ground vegetation and seed bank on plant material plots and on control plots left to natural recruitment.Although the seed bank was still dominated by agrestal and ruderal plant species, it already contained seeds of transferred species. Analyses revealed that on the plant material plots seed density of plant material species declined significantly with soil depth, just as similarity between above ground vegetation and seed bank declined. In contrast, the seed bank on control plots comprised significantly lower numbers of transferred species. We found a vertical pattern of seed bank composition: in general, the upper seed bank layer comprised more elongated and large seeds of long-lived, competitive species able to build up transient seed bank. The lower soil layer was dominated by seeds of short-lived, agrestal and ruderal species, producing small, round and long-term persistent seeds.The present study shows that the build up of a seed bank typical of flood meadows is a time-consuming process. Thus restorative management in the early phase of vegetation development should focus on fostering high seed production of transferred species.  相似文献   

13.
通过研究陕北安塞退耕3~31 a的阴阳坡10个样地的持久土壤种子库特征及其与地上植被的关系,分析持久土壤种子库在植被恢复中的作用。结果表明:调查样地持久土壤种子库由15个科36个物种组成,种子密度在1 908~12 617粒/m2之间,1年生物种占80%,随着退耕演替的进行,种子库中1年生物种比例呈下降趋势,多年生物种比例呈上升趋势,地带性物种在持久种子库中的比例也随退耕时间的延长而增加,物种数和种子库密度均随退耕演替先增大后降低;持久土壤种子库与地上植被的相似性较低,Serensen相似性系数为0.21~0.42;通过对适宜物种的确限度及土壤种子库大小的分析,认为该区退耕地的持久土壤种子库具有一定的植被恢复潜力。  相似文献   

14.
土壤种子库研究的热点问题及发展趋向   总被引:2,自引:0,他引:2  
白文娟  章家恩  全国明 《土壤》2012,44(4):562-569
土壤种子库是指存在于土壤上层凋落物和土壤中全部存活种子的总和。土壤种子库是种群定居、生存、繁衍和扩散的基础,也是植被潜在更新能力的重要组成部分,在植被的更新、演替和恢复过程中起着重要的作用。本文总结提出了土壤种子库研究的几个热点问题以及发展趋向,包括土壤种子库的研究方法,入侵植物的土壤种子库,种子雨、种子库与地上植被的关系,种子库在退化生态系统植被恢复和生物多样性保护中的作用,土壤侵蚀对土壤种子库的影响,全球变化对土壤种子库的影响。同时对这些领域的研究进展进行了综述,旨在为进一步推动今后土壤种子库的研究工作提供参考。  相似文献   

15.
汶川地震生态治理区土壤种子库及其与地上植被的关系   总被引:1,自引:1,他引:1  
为了比较地震灾区不同气候类型植被恢复区土壤种子库时空分布特征,采用野外调查取样和室内试验相结合的方法,研究了四川省汶川县威州镇和绵竹市汉旺镇4类生态治理区[干旱干暖河谷受损治理区(DHD)、干旱干暖河谷未受损区(DHU)、亚热带湿润季风气候受损治理区(HMD)、亚热带湿润季风气候未受损区(HMU)]土壤种子库的萌发动态、数量特征、物种组成、多样性特征及其与地上植被之间的关系。结果表明:未受损区具有2个萌发高峰期,受损治理区只有1个萌发高峰期,不同气候类型治理区土壤种子库在不同土壤深度表现出不同的萌发潜力;4类治理区土壤种子库平均密度为192~1 544粒·m?2,表层密度和平均密度均为未受损区受损治理区,干旱干暖河谷气候区亚热带湿润季风气候区;4类治理区共有50种植物萌发,草本植物占显著优势;HMU、HMD、DHU、DHD地上植被与土壤种子库物种组成的S?rensen相似性系数分别为26.23%、44.9%、30.77%、16.00%,Jaccard相似性系数分别为15.09%、28.95%、18.18%、9.09%;不同类型样地土壤种子库特有种和共有物种均表现出不同的生活型格局。基于以上分析结果,在灾区进行植被恢复时,应该考虑治理区的气候环境,因地制宜的进行人工引种和制定恢复措施。  相似文献   

16.
为了解北京山区土质边坡和土石边坡土壤种子库特征,在北京市鹫峰、百花山和云蒙山采用野外调查和室内萌发试验相结合的办法,研究这3个区域中土质边坡和土石边坡土壤种子库大小、物种组成及其与地上植被之间的关系。各个研究区的土壤种子库共包含54种植物,隶属于26科53属,其中有30种灌木,23种草本,1种蕨类,未观察到乔木种;土壤种子库密度介于(16 166.67±2 165.16)~(20 612.50±2 717.32)粒/m~2;各个试验地0—5cm土壤层与5—10cm土壤层种子库的种子数量垂直分布有一致的规律性,0—5cm土壤层种子库密度略高于5—10cm土壤层;土壤种子库与相应样地地上植被之间相似性指数介于0.390~0.492。通过研究发现,所选地区土壤种子库中包含大量植物种子,在合适的环境条件下,可以顺利萌发,能够满足一般情况下的生态修复要求,可以考虑作为客土在北京山区的环境修复中发挥作用。  相似文献   

17.
干旱矿区废弃地重金属生境土壤种子库时空动态   总被引:2,自引:1,他引:1  
通过不同季节野外调查取样和室外萌发试验,分析了干旱矿区重金属生境土壤种子库的时空动态。研究结果表明,该区域土壤种子库储量随季节变化存在差异。土壤种子库储量10月最高,5月份减小至最低。土壤种子库物种种类随时间的变化与土壤种子库储量相似;土壤中种子主要分布在0-5 m土层中,该层种子比例平均占种子库全部种子数量的76.5%。随着土层深度的增加,种子数量逐渐减少。5-10 cm土层中种子比例平均只占种子库全部种子数量的23.5%。10 cm以下土层几乎没有种子分布。  相似文献   

18.
The creation of small-scale vegetation mosaics by mound building is an important aspect of ant activity in grasslands. The consequences of this process for the composition of the viable soil seed bank are poorly understood. In this study we quantified the impact of the yellow ant Lasius flavus on both aboveground vegetation and seed bank of a low-intensity pasture located in the Vogelsberg area (Hesse, Germany). A few species of the mound vegetation (mainly therophytes) were restricted to the mounds, but most species also occurred in the surrounding area. The seed bank of ant mounds differed from that of the pasture soil between the mounds, with the abundance of germinating seeds being twice as high in the mounds. This was mainly due to the very large number of seeds originating from winter annuals and Thymus pulegioides. Seed abundance of most other species was lower in the mounds. Our results showed that this is partly due to dispersule weight limiting dispersal of seeds from the surrounding vegetation onto the mounds.  相似文献   

19.
元谋干热河谷山地植被修复区土壤种子库研究   总被引:9,自引:0,他引:9       下载免费PDF全文
 为了解干热河谷不同植被修复方法的土壤种子库的变化模式,采用对不同处理地段(包括水平阶间坡面、自然坡面、沟底)和对照(放牧地)的土壤种子库组成、大小进行比较研究的方法,研究元谋干热河谷山地植被修复区的土壤种子库。结果表明:1)植被修复区土壤种子库密度、丰富度均大于对照区;2)修复区内第2年土壤种子库密度、丰富度均大于第1年;3)水平阶间坡面和各类型间的土壤种子库密度差异显著;4)种子库中草本植物占很大比例;5)孔颖草和扭黄茅是种子库2大优势种。研究项目所采取植被修复措施在很大程度上改善土壤种子库的数量结构和物种组成。  相似文献   

20.
To understand how shrub cover affects the spatiotemporal patterns of the soil seed bank and to assess the role of vegetation in the restoration of desertified land in a semi‐arid region of China, we investigated the species composition and seed density of the soil seed bank under and outside the canopies over two seasons for an age sequence of Caragana microphylla shrubs in the Horqin Sandy Land region, Inner Mongolia. The results showed that a total of 24 plant species seeds were present in the soil seed bank, of which 20 were annuals or biennials. The seed densities in the soil seed bank were in the range of 830 – 13882·5 seeds m−2 at 10 cm depth. Species richness in the soil seed bank did not increase as the shrubs aged, whereas the seed densities increased significantly. Five annual species: Setaria viridis, Eragrostis pilosa, Chenopodium acuminatum, Chenopodium glaucum and Corispermum acuminatum, contributed above 90 per cent of the seeds to the soil seed bank. On the basis of seed characteristics and seed reduction amount during the growing season, we concluded that it represents a mixture of persistent and transient seeds in different proportions. More seeds accumulated under the canopies than outside the mature shrub cover, but no significant difference was found the younger cover. These results suggest that shrub size and age had an important role in augmenting seed abundance of the soil seed bank but not the species richness. We confirmed the important effects of shrub cover on seed accumulation and vegetation recovery, especially the value of more mature age vegetation for countering land degradation. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号