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.
    
Commercial seeds are widely used for re‐vegetation interventions in Mediterranean areas. These seeds mostly consist of species and varieties of non‐local provenance. The current practice relies mainly on forage or turf and fast growing species, even if it is often inefficient. Twenty‐two local populations or commercial varieties of annual and perennial species belonging to the botanical families Leguminosae, Graminaceae and Compositae were evaluated in a 4‐year field experiment in order to investigate their potential in terms of establishment and persistence in the re‐vegetation of an inactive sand quarry. Native species showed better performances than commercial varieties and encouraged further actions for the valorisation of local plant biodiversity. Among legumes, the best adapted species was the perennial Lotus cytisoides that showed high persistence in combination with other positive traits. A few annual species, that is, Melilotus indica, Trifolium subterraneum and Ornithopus sativus performed well and persisted until the end of the experiment. Among perennial grasses, Cynodon dactylon survived to drought and low soil nutrients. Both native annual grasses Lolium rigidum and Aegilops geniculata performed very well during the first 2 years of experiments. Both forbs, the perennial Cichorium intybus and the annual Chrysanthemum coronarium did not guarantee a satisfactory persistence. Some native species were evidenced, which may play an important role in the re‐vegetation of sand quarries and have good potential to be further characterized before introduction in the seed market. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

2.
    
Grasslands are impacted by many disturbances, including energy development. While temporary working platforms using access mats to support large equipment can minimize soil disturbance, less is known about matting impacts on grassland vegetation. We assessed heavy traffic effects on sandy and loamy Mixedgrass Prairie in southeast Alberta, Canada, where traffic occurred in 2015 either directly on grassland or on temporary matting. Vegetation was assessed in 2016 and 2017. Treatments varied in type (with/without matting), timing (spring vs. fall vs. season-long) and duration (6 vs. 12 weeks, and 24 weeks for season-long) of occurrence. While grass biomass was unaffected by direct wheeled traffic, native forb biomass declined, particularly during the first growing season; 1 year later, plots with prior long-term matting had more native forbs. Where traffic occurred on mats, grass biomass decreased when mats were placed for 6 or 12 weeks in spring, or for the entire growing season. Longer mat use also increased introduced forbs, which were positively associated with soil nitrogen supply rates. Plant biomass changes from matting (less grass, more introduced forbs) were more apparent in loamy-sand than loam soils. Overall, while direct traffic had limited impacts on vegetation, matting was more likely to alter vegetation, particularly when placed in spring or for longer periods, and further varied with ecosite type and the timing of traffic disturbance. We recommend that access mats be limited to placement for short periods (≤12 weeks), preferably in falling, to conserve mixedgrass prairie, while longer placement intervals be avoided.  相似文献   

3.
Tallgrass prairie restoration has been practiced for more than 75 years, yet few studies have systematically tested restoration methods over large geographic regions with the intent of refining methodology. In this study, we used three planting methods (dormant-season broadcast, growing-season broadcast and growing-season drill) fully crossed with three levels of seed species richness (10, 20, and 34 spp). We replicated the study on nine former agricultural fields located from east-central Iowa (Neal Smith National Wildlife Refuge) to northwestern Minnesota (Litchfield, Fergus Falls and Morris Wetland Management Districts), USA, within the northern tallgrass prairie biome. Objectives were to evaluate the relative influences of planting method, seed mix richness, and their interactions, on (1) planted cover (both total and by guild) and richness, (2) exotic species cover, and (3) non-planted native species cover. Optimal techniques varied between the two study areas: the dormant broadcast method produced greater cover of planted species at the Minnesota sites and the growing-season drill method produced greater cover of planted species at Iowa sites. The dormant broadcast method strongly favored establishment of perennial forbs while the growing-season drill favored warm-season grasses. Although increasing richness of the seed mix produced greater planted species richness, this did not result in greater resistance to exotic invasion. We conclude that, if planting during the growing season, drilling seed is preferable to broadcasting, but if the choice is between broadcasting seed in the dormant or growing season, the dormant season is preferred.  相似文献   

4.
Decomposed granite (DG) slopes are often difficult to revegetate after existing topsoil and vegetative cover have been removed. In this study, naturally vegetated soils and denuded DG cut slopes were evaluated to compare edaphic (soil-related) conditions that may differ between the vegetated and non-vegetated states. Potential plant nutrient deficiencies were evaluated by soil nutrient extraction, plant tissue analysis and by greenhouse bioassay methods. The DG cut slopes have approximately one-quarter to one-half the clay content, soil organic matter, water-holding capacity, and total and available nitrogen (N) of the adjacent natural soils. Soil extraction tests for phosphorus (P) availability gave variable results, but a growth response to P amendment was observed in a greenhouse bioassay. The native topsoils and the DG cut slope materials had non-limiting levels of pH, exchangeable Ca, Mg and K, and total P. Cation exchange capacity and sulfate–sulfur (S) were low but similar between the two soil groups. Principle nutrient limitations are interpreted to be N, P, and possibly S and boron (B), in order of decreasing severity. Based on these results, we conclude that the removal of humified soil organic matter on the cut slopes reduces plant growth directly by lowering several of these essential nutrients, and indirectly by decreasing the soil's water-retention and infiltration capacity. Soil organic matter is viewed as a critical factor and major contrast between barren and revegetated DG materials. © 1998 John Wiley & Sons, Ltd.  相似文献   

5.
    
Revegetation accelerates soil fertility improvement and enhances biodiversity on mine dumps. The objective of the study was to determine the status of edaphic conditions; aboveground carbon stocks; and plant diversity. The study was conducted on nickel tailings dump revegetated with Senegalia polyacantha aged 8, 9, 10 and 11 years in Zimbabwe. Results showed high bulk densities and pH values; low organic carbon; deficiency in K; and toxic levels for Ni and As implying that the tailings materials are still marginal for vegetation establishment. Limited presence of woody species suggests that the substrate is not yet suitable for colonization by such species. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

6.
This study was conducted to evaluate the effect of different wood vermicompost application rates on some soil physical and chemical properties as well as on growth parameters of a grass seed mixture (RSM 7.2.1) in tertiary sand contaminated with coal spoil. The experiment was carried out in a greenhouse over a period of 42 days. Soil was mixed with vermicompost at ratios of 0.0, 3.0, 12.5, and 25.0% and sown with the grass seed mixture. Soil samples and plant material were analyzed to determine the effect of different vermicompost application rates on the physical and chemical properties. Results revealed that the physical and chemical properties of the soil improved with increasing application rates of vermicompost. In addition, soil treated with vermicompost showed significant increases in fresh- and dry-matter yields of the grass, as well as enhanced uptake of nutrients by the grass. This indicated that treatment of contaminated soils with vermicompost may be beneficial for reclamation processes by facilitating revegetation of disturbed areas.  相似文献   

7.
    
Hydroseeding is a technique increasingly used to establish vegetation on large degraded areas, such as large‐scale road construction sites and quarries. Native grasses and legume species are used on rehabilitation and restoration projects as a first step in the recovery of such places, prior to the establishment of native forbs and shrubs that occurs at a slower pace. The effect of mycorrhizal inoculation on the development of nine species of grasses and legumes that can be potentially used in restoration processes in the Mediterranean area was studied, in microcosm experiments under greenhouse conditions. The effect of adding arbuscular mycorrhizal (AM) inoculum to a hydroseeding mixture was also investigated in greenhouse and in field conditions. In the hydroseeding experiments the mycorrhizal inoculum was added to the seed slurry in a jet agitated hydroseeding machine and sprayed to the soil surface with a pressurised spray in a one‐step application. The study shows that Glomus intraradices Schenk & Smith BEG72 is able to establish the symbiosis when applied at sowing while Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe BEG116 is not. It also confirms that legumes are more highly mycotrophic than grasses. The results of the hydroseeding experiments demonstrate the establishment of the symbiosis using this technology, both in the greenhouse and in the field. Mycorrhizal inoculation improved above ground plant growth and increased the legumes/grasses ratio. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

8.
将生态系统健康理论引入路边生态系统,选择纵向岭谷区大保(大理-保山)和思小(思茅-小勐养)两段高速公路作为案例工程,采用生态系统距离指数、协调指数和健康指数对高速公路沿线生态系统的健康状态进行了尝试性评价,进而分析了高速公路建设对沿线生态系统健康的影响.结果表明,高速公路建设对沿线生态系统健康产生了一定程度的影响,其影响范围可能在200m内,且距离高速公路越近,其影响强度越大;不同地理位置和地貌条件下高速公路建设对沿线生态系统健康的影响强度不同,大保高速公路的影响作用强于思小高速公路(除山腰路段沿线0~50 m),不同地貌条件下其影响程度的强弱比较满足:山腰>山顶.  相似文献   

9.
    
Legislation requiring the rehabilitation of new opencast coal mines came into effect in New South Wales, Australia, in 1973. Mining companies now stockpile original topsoil which is later spread with fertilizer over re-shaped overburden and waste carbonaceous material. Problems in successfully revegetating new surfaces are exacerbated by the thinness and infertility of natural soils, which are deficient in phosphorus and moderately acid. Revegetation has not been successful on untreated mine waste and overburden. This study provides a general overview of some aspects of post-rehabilitation soil chemistry and vegetation on these soils. A limited number of samples, collected from three mine sites having different rainfall and varying ages of rehabilitated areas, were tested for pH, EC, organic carbon, total phosphorus and available aluminium. Rehabilitated areas were all characterised by very low levels of total phosphorus, neutral pH, and variable and relatively low organic carbon, and some showed aluminium toxicity. Heavy application of gypsum at one of the steeper sites was associated with acid pH, high EC values, low total P, Al toxicity, some soil erosion and little plant cover. Except for this site, the variable vegetation cover at the sites studied seemed adequate for long-term re-establishment, despite serious weed invasion at some non-studied sites, soil loss on newly re-formed surfaces, and generally poor natural and rehabilitated soils.  相似文献   

10.
    
Catastrophic soil erosion has resulted in the desertification of vast areas in Iceland. Barren lands are revegetated on a large scale by aerial broadcasting of commercial grass seed of Festuca rubra cv. Leik (red fescue) and subsequent regular fertilizer application for five years. Vegetation cover following aerial seeding of F. rubra was recorded in three reclaimed sites, which were two, ten and 25 years old, in an inland area in southern Iceland. As a comparison, vegetation cover was also recorded on barren land. Plant succession was inferred from these records. Vegetation cover was recorded using the point-intercept method. Spores of arbuscular mycorrhizae fungi (AMF) were recorded from each site. Barren lands have characteristically low (<5%) vegetation cover. The highest cover of F. rubra was found two years after revegetation was initiated. Non-dependent AMF forbs also colonized and increased their cover rapidly in the second year due to fertilizer application, but after a decade their cover declined. Ten years after the aerial seeding, F. rubra disappeared and the area was dominated by the native grass Agrostis stolonifera (creeping bent grass). A cover of mosses and plant litter was also recorded on the ten-year-old site. AMF spores were low in all studied sites, and colonization of AMF was only found in the roots of A. stolonifera. After 25 years, it appeared that the cover of native forbs started to increase again and salix bushes were established. Aerial seeding of F. rubra failed to create a long-lasting cover to facilitate natural rapid succession. Alternative revegetation practices, taking into consideration the dynamics of the mutualistic microorganisms (Rhizobium and AMF)/plant association, are suggested for a better and more economic management of reclamation strategies. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

11.
    
Few plants can tolerate the loose sandy‐soils of the arid deserts. Selection of native plants that could be used in rehabilitation of degraded deserts necessitates information about their seed dormancy and germination requirements. This study assessed the effects of light and temperature requirements during germination for eight common perennial grasses that have the potential to rehabilitate the arid Arabian deserts. The selected grasses vary considerably in seed mass. Germination of clonally propagated grasses (six species) was significantly greater, but slower, than that of two non‐clonal grasses. Four of these six species (Lasiurus scindicus , Panicum turgidum , Aeluropus lagopoides and Halopyrum mucronatum ) produce larger seeds and attained greater germination in both light and darkness at a wide range of temperatures. However, the other two (Centropodia forsskaolii and Coelachyrum piercei ) produce medium‐sized seeds with higher dormancy. Smaller seeds of Sporobolus arabicus were positively photoblastic at all temperatures, but those of Sporobolus spicatus were neutrally photoblastic at lower temperatures and positively photoblastic at higher temperatures. There was a significant negative relationship between seed mass and relative light germination, indicating that small seeds require more light during germination. It is recommended to use seeds of the six clonal grasses for restoration of degraded arid deserts. The ability of these grasses to germinate in different light and temperature regimes indicates their ability to germinate at any time of the year, even when seeds are buried. The light and temperature requirements of the different grasses are explained in the light of their adaptation and distribution in natural habitats. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

12.
贡嘎山旅游景区泥石流灾害及减灾对策   总被引:2,自引:0,他引:2       下载免费PDF全文
采用文献资料法和理论分析法,探讨了矿区沉陷地复垦与生态重建的若干问题,目的在于提高矿区环境治理投资效果,促进矿区可持续发展.构建了矿区沉陷地复垦与生态重建的主要理论、关键技术和投资效果评价方法.最后指出,矿区沉陷地环境治理中,应将土地复垦与生态重建相结合.  相似文献   

13.
    
Brine, produced as a by‐product of oil extraction, when contained in evaporation ponds can cause soil salinization in the vicinity of these ponds. Native halophytes may assist revegetation and rehabilitation of these salt‐affected soils. This study was conducted to investigate the revegetation and rehabilitation potential of brine‐affected land using native halophytes (Tecticornia pergranulata (J.M.Black) K.A.Sheph. & Paul G.Wilson, Sclerolaena longicuspis (F.Muell.) A.J.Scott and Frankenia serpyllifolia Lindl). Soil samples from adjacent bare and vegetated areas of brine‐affected land were compared to assess the physico‐chemical properties associated with the vegetation cover. The salt contents of the halophytes, plant bioaccumulation, bioconcentration, and translocation factors were measured to evaluate remediation capacity of the species. We hypothesized that the halophytes reduce the ions' concentrations and thus soil salinity and sodicity. The examined halophytes were associated with a reduction in salinity and sodicity by an average of 38.5% and 33% in the top 10 cm of the soil, respectively. Tpergranulata had the highest shoot Na+ content (98 g/kg dry wt), bioaccumulation (14.21), and translocation (23.09) factors for Na+ that indicated the higher remediation potential of this species. Despite the high remediation potential of the examined species, halophytes are not able to reduce the salt content of the landscape to create conditions for the growth of glycophytes. However, the salt‐affected land can be revegetated by halophytes, and halophytes probably provide a stable vegetation cover for the landscape in ecological succession. An improvement in soil physical properties is required for revegetation success.  相似文献   

14.
Mining activities along the west coast of South Africa will lead to salinization of the soil if sea-water is used in the mining process. Laboratory studies were conducted to determine the influence of leaching depth and the amount and frequency of irrigation on the growth of Atriplex semibaccata R. Br. Leaching depth as well as the amount and frequency of irrigation had no significant effect on biomass production. However, the interaction between leaching depth and amount of irrigation did influence the biomass production of Atriplex semibaccata. Root:shoot ratio increased as the amount of irrigation decreased.  相似文献   

15.
    
Exposed, steep earthy road slopes (ESERs) in the semiarid loess region of China are prone to soil erosion and are difficult to revegetate. Topsoil desiccation (TSD) leads to land degradation, which limits the revegetation success. In this study, TSD was assessed on south‐facing ESERs (with slopes of 45–55°, 55–65°, 65–75°, and >75°), and a revegetation method using the deep planting of container seedlings of 3 species (both native and introduced species) was designed to overcome the problems associated with TSD. Plant growth was evaluated by measuring plant height and diameter of the stem base after 4 growing seasons. The following results were obtained: (a) TSD occurs on south‐facing ESERs and persists after the rainy season. The thickness of the TSD layer remained at approximately 15 cm (<20 cm for all studied slope grades) on the slopes with a formation time of approximately 3 years as of the beginning of this study, and the thickness increased to 35–40 cm on the control slope after 4 years of the study. (b) Using the deep planting of container seedlings method, plant roots can completely penetrate the TSD layer. The selected native species (Caragana korshinskii Kom. and Tamarix chinensis Lour.) and introduced species (Caryopteris clandonensis ‘Worcester Gold’) all survived; among them, Tchinensis Lour. exhibited the best growth and the best adaptation to changes in slope grade. The applied method can also effectively inhibit further increases in TSD and can be used in semiarid loess regions and similar areas.  相似文献   

16.
    
When plants establish in novel environments, they can modify soil microbial community structure and functional properties in ways that enhance their own success. Although soil microbial communities are influenced by abiotic environmental variability, rhizosphere microbial communities may also be affected by plant activities such as nutrient uptake during the growing season. We predicted that during the growing season, plant N uptake would explain much of the variation in rhizosphere microbial community assembly and functional traits. We grew the invasive C3 grass Bromus tectorum and three commonly co-occurring native C3 grasses in a controlled greenhouse environment, and examined rhizosphere bacterial community structural and functional characteristics at three different plant growth stages. We found that soil N availability and plant tissue N levels strongly correlated with shifts in rhizosphere bacterial community structure. It also appeared that the rapid drawdown of soil nutrients in the rhizosphere during the plant growing season triggered a selection event whereby only those microbes able to tolerate the changing nutrient conditions were able to persist. Plant N uptake rates inversely corresponded to microbial biomass N levels during periods of peak plant growth. Mechanisms which enable plants to influence rhizosphere bacterial community structure and function are likely to affect their competitive ability and fitness. Our study suggests that plants can alter their rhizosphere microbiomes through influencing nutrient availability. The ways in which plants establish their rhizosphere bacterial communities may now be viewed as a selection trait related to intrinsic plant species nutrient demands.  相似文献   

17.
以成都平原复垦宅基地土壤为对象,研究3类种养废弃物(秸秆、猪粪和菌渣)与化肥配施下土壤酶活性、微生物数量的动态变化及其相关性。结果表明:(1)3类\"种养废弃物+化肥\"配施相比空白(CK)和常规施肥(CF)方式,均能显著提高复垦宅基地土壤微生物数量和土壤酶活性。(2)小麦成熟期,0—20,20—40cm土层土壤微生物总数分别在猪粪还田(MCF)和菌渣还田(FCF)下达到最大值26.89×10~6 cfu/g和17.82×10~6 cfu/g。MCF和FCF处理下3种微生物(细菌、真菌和放线菌)数量都显著高于SCF处理,但MCF和FCF处理之间基本无显著差异。(3)归一化的土壤酶活性值除在0—20cm土层MCF处理达到最高值0.140外,其余均在FCF处理下达到最大。在小麦成熟期,土壤脲酶、蔗糖酶和过氧化氢酶活性基本呈现出FCFSCFMCF的规律(除0—20cm土层土壤脲酶)。(4)5种处理下的土壤酶活性、微生物数量、土壤有机碳及全氮之间均表现出显著相关。(5)0—20cm土层种养废弃物配施处理下微生物数量、脲酶及蔗糖酶活性在小麦生育期内呈倒\"U\"型变化趋势,过氧化氢酶活性呈不断上升的趋势;20—40cm土层微生物数量和土壤酶活大致呈递增趋势。(6)综合分析表明,\"菌渣+化肥\"配施处理(FCF)为成都平原复垦宅基地土壤培肥较适宜方式。  相似文献   

18.
种草对马尾松林地植被多样性的影响   总被引:1,自引:1,他引:1  
治理前 ,试验地植物种类稀少 ,水土流失严重 ,1983年种植 2 0余种草本植物进行治理 ,翌年植被覆盖恢复 ,基本控制了水土流失。 17年后林下植物种类组成发生较大变化 ,共有 14种灌木、8种草本和 1种藤本植物 ,前期种植的草本植物已退出。但由于土壤贫瘠、干旱 ,林下植被中耐干旱瘠薄的灌木和芒萁占绝对优势 ,Shannon wiener等多样性指数和均匀度指数仍较低 ,进展演替极为缓慢。如何对群落进一步进行调控和管理 ,以加速进展演替 ,有待进一步研究。  相似文献   

19.
乌江流域水土流失区退耕还林措施和对策   总被引:1,自引:0,他引:1       下载免费PDF全文
乌江流域是贵州经济发展的黄金地域,对振兴贵州经济及对西南地区建设具有重要战略意义。为了使生态系统向良性循环转化,必须从退耕还林还牧(草)入手。其主要措施、对策:(1)执行有关技术政策:(2)摸清底子,制订退耕还林还牧规划:(3)流域治理开发首先抓住一个核心,实现两个调整;(4)群决群众后顾之忧,进行外部、内部经济补偿;(5)从实际出发,退耕既要坚定不移,又要稳妥,不能一刀切;(6)帮助农民寻求近期受益的致富门路,搞好剩余劳力转移;(7)进行生态农业、生态林业建设。  相似文献   

20.
乌江流域是贵州经济发展的黄金地域,对振兴贵州经济及对西南地区建设具有重要战略意义。为了使生态系统向良性循环转化,必须从退耕还林还牧(草)入手。其主要措施、对策:(1)执行有关技术政策:(2)摸清底子,制订退耕还林还牧规划:(3)流域治理开发首先抓住一个核心,实现两个调整;(4)群决群众后顾之忧,进行外部、内部经济补偿;(5)从实际出发,退耕既要坚定不移,又要稳妥,不能一刀切;(6)帮助农民寻求近期受益的致富门路,搞好剩余劳力转移;(7)进行生态农业、生态林业建设。  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