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81.
Although the consequences of the homogenization of Earth’s flora and fauna are not well understood, experts agree that biological invasions pose hazards to rare species. As a result, there is a need for a systematic approach to assess risks from invasive species. The Relative Risk Model can be adapted to assess combinations of rare species, invasive species, and regions. It also can be applied to different taxonomic groups and at different spatial scales. This flexibility makes it a promising tool for invasive species risk assessment. We used the Relative Risk Model to quantify risks posed to endangered plant species by non-indigenous invasive plant species in Nebraska.We modeled the suitable habitats for eight invasive plant species, which we subsequently compared to documented occurrences of endangered plant species in a Geographic Information System. We combined this data with an assessment of the ecological impacts of each invasive species in a regional risk assessment framework to simultaneously calculate relative risk scores for invasive plant species, imperiled plant species, and subregions. We assessed uncertainty with Monte Carlo simulations.The results of this assessment are discrete values indicating the relative threat posed by invasive species to rare species, the relative risk posed to the rare species, and the relative risk in subregions. Results indicate that the invasive species Elaeagnus angustifolia and Rhamnus cathartica pose the greatest risks to endangered plants in Nebraska. The rare species Panax quinquefolius and the subregion Western Corn Belt Plains show the highest risk scores. 相似文献
82.
近年来,关于UV-B辐射变化对植物影响的研究有了许多新的突破。该研究主要综述了UV-B变化对植物影响的相关研究进展,分析了植物不同方面对紫外光UV-B变化的响应以及UV-B与其他胁迫共同作用对植物的影响,同时展望了UV-B变化对植物甚至对整个生态系统影响等问题中值得进一步讨论和探究的问题。 相似文献
83.
84.
从污染的土壤中筛选出两株较高抗铅细菌(CJ1,CJ2)和两株真菌(ZJ1,ZJ2),经过菌株的液体培养对铅的除去率达到了60.6%、51.3%、78.7%、47.2%。其中选择两种去除率高的细菌CJ1和真菌ZJ1,通过黑麦草的盆栽试验,在其内添加不同种类的微生物、EDDS(乙二胺二琥珀酸)及微生物与螯合剂的复合调控,分析了黑麦草吸收铅能力。结果发现,EDDS和真菌的复合处理下黑麦草根系和叶片中的铅含量分别比对照增加了7.7倍和10.68倍。说明复合处理对铅在黑麦草体内的富集和传输上有显著的诱导作用。 相似文献
85.
植物组织培养实验教学研究 总被引:1,自引:0,他引:1
植物组织培养是现代生物技术的重要组成部分,也是园艺专业学生的必修课程。近几年,在植物组织培养实验教学大纲修订、实验内容设计、资源合理利用、实验考核等方面进行了研究和探索,取得了较好的实验教学效果。 相似文献
86.
《Scandinavian Journal of Forest Research》2012,27(1):37-43
The formation of the organic layer within Scandinavian forest soil started about 10000 yr ago, following the retreat of the continental ice sheet. Since then the land has been slowly rising in northern Europe and uplift still occurs on the coast of the Bothnian Bay at a rate of about 0.6-0.9 m per 100 yr. Four, 300 m long, successional gradients were studied from the shoreline to a Scots pine (Pinus sylvestris) stand with a fully developed humus layer of a few centimetres' thickness. The plantless shoreline was followed by small foredunes and dunes, characterized by Agrostis stolonifera and Leymus arenarius, respectively, and the deflation basin characterized by lichens and sparse Festuca ovina and Deschampsia flexuosa. The study sites situated in Scots pine stands of about 25 and 40 yr age were characterized by sparse dwarf shrubs, lichens and bryophytes. The amount of organic matter in soil increased along the gradient. When the microbial biomass, estimated as indicative phospholipid fatty acids (PLFAs), was calculated on the organic matter basis, the total microbial biomass as well the amount of bacterial PLFAs decreased from the earlier stages of succession towards the pine forest. The ratio of fungal to bacterial PLFAs increased along the succession. The bacterial community structure in the shore soil was different to that in the dune soil or in forested zones. On the plantless shore the microbial community was almost completely described by PLFAs indicative of Gram-negative bacteria. In addition to these bacterial PLFAs, dunes were characterized by PLFAs indicative of actinomycetes. Thus, the fungal part of the microbial community seemed to respond most to the accumulation of organic matter and increasing C/N ratio, while the bacterial biomass and bacterial community structure seemed also to reflect the composition of the vegetation and the varying quality of the organic matter. 相似文献
87.
采用高效液相色谱分析方法分析测定植物样品中的叶黄素含量,对不同的前处理方法进行了实验。最佳测定方法为利用植物冻干样,以丙酮为提取液进行HPLC测定。利用上述方法进行一些植物中的叶黄素含量的测定,结果表明在所测定的几种植物中,叶黄素的含量差异很大。其中羽衣甘蓝的含量最高,其次为白薯叶、苋菜、菠菜等。 相似文献
88.
二氧化硫对植物的影响及植物的自我修复 总被引:3,自引:0,他引:3
近年来SO2污染比较严重,它对植物有着多方面的影响。目前,SO2单一污染物对植物生理生化的直接影响已比较清楚,但SO2对植物的间接影响以及SO2与其他污染物对植物的复合影响,特别中在分了水平上研究SO2的影响等内容尚不清楚。植物一方面要受到SO2污染的影响,另一方面又对SO2的影响具有一定程度的修复能力。植物细胞保护酶通过清除活性氧在植物的自我修复中起着重要的作用。 相似文献
89.
山东省常见带刺植物研究 总被引:2,自引:0,他引:2
通过对植物学的学习和实习考察,大体掌握植物的分类,对于易混淆植物难以鉴别,特征掌握不全面。鉴于此,结合野外考察将一些易混淆的带刺植物分科属加以区别,并以个别种属举例说明,以此加深理解,对以后分类提供帮助。 相似文献
90.
介绍了湛江市在创园中所采取的相关措施,探讨在加强城市景观与生态敏感区保护、利用乡土植物资源、构建高绿量植物群落、加强管理等方面的实践,提出了“低成本高效益”的生态创园工作理念。 相似文献