【作者】 李明丽；

【导师】 郭水良；

【作者基本信息】 浙江师范大学 ， 植物学， 2010， 硕士

【摘要】 近年来,随着经济、社会及各种对外交流的发展,外来植物入侵风险逐渐增加。江浙沪地区作为我国的对外交流、经济贸易中心,外来入侵植物的数量急剧增加,因此必须建立适应本区域的外来植物入侵性风险评估体系。本文主要以江苏、浙江和上海为研究区域,进行草本植物的生态学调查,通过对植物性状与入侵性,植物分布与环境因子等关系的研究,找出构建本区域外来植物入侵性风险评估体系的指标,构建相应的入侵风险评估系统。主要研究结果如下：1.江浙沪地区共调查有171种外来植物,隶属38科74属。本区域的外来植物种类种类丰富,优势科现象明显,菊科最多(47种),其次是禾本科(29)、豆科(13)和苋科(10)；该地区外来植物地理分布类型中热带分布占大多数,区系特点是比较年轻的,主要来自美洲(56%)和欧洲(29%),因此在引种时应加强对这些原产地物种的控制。2.通过对江浙沪地区植物的生态调查,以498个样地,431种植物的生态重要值为基础,计测其生态位宽度发现,猪殃殃、野塘蒿、小飞蓬、加拿大一枝黄花、一年蓬出现的频率最高,在调查区域有广泛的分布；498个样地中总的生态重要值最高的分别是加拿大一枝黄花(23.099)、猪殃殃(20.802)、大巢菜(16.865)、葎草(16.635)、野老鹳草(11.642)、野塘蒿(11.447)等,这些都是危害大、入侵性强的植物；生态位宽度最大的分别是猪殃殃(5.193)、野塘蒿(5.044)、加拿大一枝黄花(4.804)、小飞蓬(4.817)、一年蓬(4.542)和钻形紫菀(4.041),这些植物都具有更强的入侵能力,更能够适应多样化的生境。因此,植物的生境多样化程度可以作为构建风险评估系统的一个指标,分布于多样化生境的,应赋予较大的权值。3.基于498个样地植物的野外调查,建立样地-环境因子数据矩阵,运用SPSS 13.0中的Bivariate相关性分析模块,计算生态重要值和人为干扰度之间的相关系数,探讨这种相关性与植物杂草性(入侵性)之间的关系。发现调查区域内生态重要值与人为干扰度间相关系数最大的分别是狗尾草(0.313)、牛筋草(0.265)、马唐(0.251)、加拿大一枝黄花(0.227)、钻形紫菀(0.222)和苍耳(0.213)等,这些植物均为杂草或重要的外来入侵植物；最不适于生活在人为干扰环境的植物有三脉叶马兰(-0.250)、鱼腥草(-0.239)、野大豆(-0.238)、过路黄(-0.235)、渐尖毛蕨(-0.225)、绞股蓝(-0.225)等,结合文献资料和野外观察,表明生态重要值与人为干扰强度间的相关系数越大,植物的入侵能力也越强,此相关系数可以作为植物对人为干扰环境的一种入侵能力,再进一步分析这种相关系数(即入侵能力)与植物学性状间的关系。4.计测了421种被子植物26个植物学性状,统计分析了这些性状和入侵性之间的关系。发现该地区具有入侵倾向的植物多数具有以下性状：一、二年生生活型、没有营养繁殖器官如块根、块茎等、花部呈辐射对称、两性花、传播体(果实或种子)小、种子数量多、生活在阳生生境中、植株直立、风媒传粉、果实或种子无刺、植株有毒等。5.文献检索表明,具有入侵性的植物一般都具有较小的DNA C-值,染色体倍性高,种子具有休眠且萌发不整齐,通过释放化感物质抑制土著植物的种子萌发和幼苗生长。针对前人在植物入侵风险评估系统中存在的不足,结合本文的研究结果,结合文献检索资料,提出了江浙沪地区外来植物入侵性风险评估体系。该体系共包括5个一级指标,27个二级指标,各指标的加权值即是最终的评估分数,得分0-29的,可以接受,允许其引进；得分30-59的,有一定的风险,引入后采取一定的措施严格控制其逃逸和扩散；得分60-100的,入侵风险高,不可接受,必须禁止引进。最后选取本地区有分布的54种外来植物对该评估系统进行验证,确认了这一系统的合理性。更多还原

【Abstract】 In recent years, with the development of economic,social and foreign exchange, alien plant invasions become more and more evident. As foreign exchange, economic and trade center of China, the number of alien invasive plants in Jiangsu, Zhejiang and Shanghai increased dramatically, so a Risk Assessment System for exotic plants in this area should be established to prevent plant invasions effectively. Based on the current theory of invasion ecology, the investigation of herbs in Jiangsu, Zhejiang and Shanghai, the relationship between attributes of plants and invasiveness, distribution of plants and environmental factors, the indices in relation to plant invasiveness were identified, thus a risk assessment sysment for exotic plants in Jiangsu, Zhejiang and Shanghai were established. The main results are:1. The species of alien plants in Jiangsu, Zhejiang and Shanghai were surveyed with the square plot method in different habitats. Based on our investigation, together with the literature, 171 alien plant species, belonging to 74 genera and 38 families, were confirmed. Among them,Compositae (47 species), Gramineae (29), Leguminosae (13), Maranthaceae (10) are the dominant families. In this region, the proportion of tropical distribution of these 171 alien plant species was higher, floristic characteristic was younger. Totally about 85% of the alien plants originate from America (56%) and Europe (29%), so appropriate measures to control the introduction of the plants from America and Europe are essential.2. Based on the ecological important value of 431 plants in 498 sites, their niche breadth was calculated based on the Shannon equation. Galium aparine var. tenerum, Conyza bonariensis, Conyza canadensis, Solidago canadensis and Erigeron annuus had the highest frequency and a broad distribution; Solidago canadensis, Galium aparine var. tenerum, Vicia sativa, Humulus scandens, Geranium carolinianum and Conyza bonariensis, had the largest total important values, being 23.099,20.802,16.865,16.635,11.642 and 11.447, respectively; Galium aparine var. tenerum, Conyza bonariensis, Solidago canadensis, Conyza canadensis, Erigeron anuus and Aster subulatus had the largest niche breadth, being 5.193,5.044,4.804, 4.817,4.542,4.041, respectively, which means that these plants are higher invasive because of their ability to adapt to diverse habitats. Therefor, the degree of diverse habitats for a apecies could be used as an indicator to build risk assessment system.3. Pearson correlations between the ecological important value and the disturbance intensity were calculated to elucidate the ability to adapt the disturbed environment for a species.The results showed:Setaria viridis, Eleusine indica, Digitaria sanguinalis, Solidago canadensis, Aster subulatus, Xanthium sibiricum had the largest correlation coefficients, being 0.313,0.265,0.251,0.227,0.222 and 0.213, respectively; while Aster ageratoides Aster ageratoides (-0.250), Houttuynia cordata (-0.239), Glycine soja (-0.238), Lysimachia christinae (-0.235), Cyclosorus acuminatus (-0.225) and Gynostemma pentaphyllum (-0.225) had the largest negective correlation coefficients, being less than -0.225. According to the investigation in the field, as well as the check of related literature, the larger the correlation coefficient was, the more suitable for a species to grow in the disturbed ebvironment, and thus the plant had laeger invasiveness.4. A total of 26 characters of 421 plants in Jiangsu, Zhejiang and Shanghai were recorded, and the relationship between these characters with their invasiveness (namely the correlation coefficient between the ecological important value and the disturbance intensity for a species) were analyzed. Our results showed that the invasive plants tend to have annual or biennial life form, toxic. These plants also adapted to xeric or suuny habitats. They are likely to have wind pollinated bieesual flowers, actinomorphic flowers and produce many small mucilaginous or armed seeds. They are unlikely to have thorns, or reproduce vegetatively.5.Invasive plants are generally characterized by having smaller DNA C-values, dormancy and irregular germination seeds; higher polyploid and allelochemicals to inhibit seed germination and seedling growth of indigenous plants. Sum up the above, a risk assessment system was established about invasive plants in Jiangsu, Zhejiang and Shanghai. This system includes five one-level indexes and 27 two-level indexes, the weighted value of each index is the final assessment scores. A species whose assessment scores from 0 to 29 is acceptable, allowing it to introduce, those from 30 to 59 is of certain risk, certain measures should be taken after introduction to control their escape and spread, and those from 60 to 100 is of high risk, and are unacceptable, we must prohibit them from introduction. Finally,54 exotic plants in Jiangsu, Zhejiang and shanghai were selected to authenticate this system.更多还原