杭州市外来入侵植物初步研究

通过对杭州市7区、县(市)的野外调查,结合有关文献资料的整理和分析,确定杭州市主要外来入侵植物72种,隶属30科63属.对外来入侵植物的生境特点、入侵途径及危害性进行分析,提出加强植物检疫、谨慎引种,建立植物风险评估体系,开展对外来入侵植物利用的研究等加强对外来入侵植物管理和控制的对策.     

我国外来入侵物种的危害及防治对策初探

外来入侵物种已经对我国的生态环境保护、社会经济等构成了严重的危害。本文介绍了外来入侵物种的概念和入侵途径及危害现状，提出了外来物种入侵的防治对策。     

珠海市外来入侵植物调查

据初步调查统计,珠海市共有外来入侵植物25科51属56种,多为草本。文中对这些植物的入侵途径和危害进行了分析,并提出一些防治建议。     

衡阳市外来入侵植物调查

通过采取样方调查和样线调查相结合的方法,结合查阅相关文献资料,初步确定衡阳市现有外来入侵植物39种.这些外来入侵植物隶属于20科,其中菊科和苋科最多,分别为9种、5种;陆生37种,水生2种.目前有13种已显现暴发式增长,其他外来入侵植物暂处时滞阶段.这些外来入侵植物大多分布在人类活动频繁或植物生态系统遭破坏的地区,这说...     

珠海市外来入侵植物调查

据初步调查统计,珠海市共有外来入侵植物30科61属67种,多为草本.对这些植物的入侵途径和危害进行了分析,并提出一些防治建议.     

要重视和防范外来有害生物的入侵危害

该文论述了外来有害生物危害的严重性和治理工作的艰巨性，以及生物入侵防范工作在我国生态环境建设和保护中的重要地位。提出了加强外来有害生物入侵防范工作的6项措施。     

济南外来入侵植物三裂叶豚草的危害与防治

三裂叶豚草植物繁殖和再生能力强,适应性广,传播迅速,是世界公认的公害性杂草。不仅是一种恶性农田杂草,也是一种致敏性植物。豚草传入我国历史不长,分布区域不太广,其危害性刚刚显露,因此有关部门应加强检疫,采取有效措施予以消灭。     

西双版纳外来入侵植物初步调查

经调查,云南西双版纳现已知的外来入侵植物约有75种,并对其入侵的途径和入侵后对西双版纳的生态环境、生物多样性、农业生产带来的影响和危害进行了讨论。     

湖北省外来入侵植物研究

通过实地调查和查阅文献,研究了湖北省外来入侵植物的种类、原产地、生活型等。结果表明:当前湖北省共有外来入侵植物114种,隶属于28科,其中,在外来入侵植物中,菊科最多(34种),占总数的29.8%;豆科次之(14种);禾本科排第3位(11种)。从入侵湖北省的外来入侵植物总体构成来看,以来自美洲的外来植物种类最多(66种),占57.9%,其次为欧洲(29种),占25.4%,亚洲和非洲较少。笔者还对湖北省外来植物的入侵现状进行了讨论。     

云南外来入侵植物研究

在查阅资料及多年实地观察的基础上,首次系统地对云南的外来入侵植物进行了研究。明确了云南现有的外来入侵植物计有129种,经对这些植物进行种类、来源、性状的构成以及危害程度的统计分析。结果表明,云南的外来入侵植物有39科,86属。含5种以上的有8科,来源于南美热带的种类最多,达63种,占云南外来入侵植物种数的49%;草本植物97种,占云南外来入侵植物种数的75%。依据这些外来入侵植物在云南的分布情况和在其分布地的优势度并予赋值,以此划分它们的危害等级。具Ⅰ级危害程度的有6种,Ⅱ级危害程度的有34种,Ⅲ级危害程度的有89种。据此得出云南外来入侵植物的种类数量居全国之首,已成为我国外来入侵植物最严重区域的结论。应引起相关部门的高度重视,采取有力措施,防止危害进一步加剧。     

外来植物入侵对生态安全的威胁

外来植物入侵是外来物种入侵的组成部分,也是威胁我国生态安全的重要因素之一,它改变了原有的植物种群结构,给生态环境和生物多样性造成极大的破坏,也给农林业造成了巨大的损失,直接威胁到国家生态安全。因此,加强外来植物入侵的防范和管理已是当务之急。本文简要介绍了外来入侵植物的概念、入侵途径及危害现状,并对提出了外来植物入侵的防治对策。     

Patterns of exotic plant invasions in Pennsylvania’s Allegheny National Forest using intensive Forest Inventory and Analysis plots

Intensive Forest Inventory and Analysis (FIA) plot data collected in the Allegheny National Forest (ANF), Pennsylvania, between 1999 and 2006 were evaluated for their ability to predict ANF’s vulnerability to invasion by exotic plants. A total of 26 variables classified by biotic, abiotic, or disturbance characteristics were examined. Likelihood of colonization by invasive exotic and non-invasive exotic plants was analyzed using a logistic regression model. Approximately, 11% of the 449 species documented in these plots were exotic, which is higher than has been found in other northeastern forested plots. Only 1% of the ANF flora was invasive exotic plants and these were at low abundance, confirming that most invasions are still at an early stage of establishment. Sites richer in native or non-invasive exotic plants and with more alkaline soils were more likely to be invaded. Younger forests, forests with non-forest patches present, and forests rich in native species were more likely to be colonized by exotic (invasive or non-invasive) plants. Frangula alnus, which is starting to spread locally, differed from the other invasive exotic species in terms of its association with high sapling density to tree density ratios, high soil nitrogen levels, and the presence of fire. Variables representing mortality due to beech bark disease and distance to the nearest exotic planting manifested counterintuitive results. In both cases, the combined occurrence of mortality due to beech bark disease or a close (less than 500 m away) known propagule source and the presence of an invasive or non-invasive exotic plant was rare. We encourage increased use of intensive sampling for FIA in the U.S.A. and similar monitoring programs in other countries, but suggest adding a step to the plot selection phase that would allow forest-wide or regional stratified sampling of typically coarse-scale variables, such as historic or predicted defoliation or fire events, and forest or land type. A more accurate picture of the importance of disturbance variables in defining forest vulnerability to plant invasion may be achieved.     

The effect of herbivory on seedling survival of the invasive exotic species Pinus radiata and Eucalyptus globulus in a Mediterranean ecosystem of Central Chile

Herbivory may be an important factor affecting seedling survival of exotic species invading new habitats. We evaluated the effect of vertebrate herbivory on the seedling survival of two widely planted and invasive tree species (Pinus radiata and Eucalyptus globulus), in a Mediterranean-type ecosystem of central Chile. An important role of herbivory on seedling survival of these two species in their introduced ranges has previously been documented. However, this has mainly been evaluated in forest plantations where habitat and vegetation conditions differ from wild habitats in which invasion occurs. We planted seedlings with and without protection against vertebrate herbivores in different aspects (a mesic south-facing slope and a xeric north-facing slope) and vegetation cover (open sites and sites with patchy tree cover). We found that regardless of aspect or vegetation cover, herbivory, in this case mainly caused by exotic vertebrates, significantly and negatively affected seedling survival of both species. However, while the effect of herbivory on P. radiata was significant in every vegetation and habitat condition, for E. globulus, the effect of herbivory was significant only for open sites in the mesic habitat. These results suggest that, as observed in forestry plantations, vertebrate herbivory may constrain seedling establishment of these two exotic trees and potentially impede the invasion. However, the importance of herbivory in controlling exotic species may vary depending on the vegetation and habitat conditions in some species such as E. globulus.     

Allelopathic effects of invasive Eucalyptus camaldulensis on germination and early growth of four native species in the Western Cape,South Africa

Eucalyptus camaldulensis Dehnh. (red river gum; Myrtaceae) is an invasive tree in riparian habitats of the Western Cape, South Africa, where it replaces indigenous vegetation and affects ecosystem functioning. These invasions lead to changes in river geomorphology and reduction in stream flow. The mechanisms that drive these effects are poorly understood. The potential for allelopathic effects of aqueous extracts of E. camaldulensis tissues and of soil and litter collected beneath E. camaldulensis trees on the germination and seedling growth of four selected native plant species was investigated in a greenhouse experiment. Soils collected beneath E. camaldulensis trees were used in three treatments: untreated soils, sterilised soils and sterilised soils overlaid with a eucalypt litter layer. In addition, soils collected from underneath native species were used in two treatments: untreated soils and soils overlaid with a eucalypt litter layer. All soil treatments were watered with three E. camaldulensis leaf, bark and root aqueous treatments. Compounds present in the aqueous extracts and fresh samples were identified using gas chromatography. Soil and aqueous treatments showed varying effects on germination and seedling growth of the four native species. Germination and seedling growth of Olea europaea subsp. africana and Dimorphotheca pluvialis were significantly reduced by E. camaldulensis root and bark aqueous extracts as well as by the soils treatments. The addition of eucalypt litter to native and sterilised soils reduced shoot and root growth of all four native species. Compounds such as -phellandrene, eucalyptol, p-menth-1-en-8-ol and -pinene, which have the potential to inhibit germination and plant growth, were identified in E. camaldulensis aqueous extracts and fresh samples. Although the methods applied in this study had limitations (e.g. lack of control treatment to litter addition), the results provide an additional motivation to prioritise removal of invasive E. camaldulensis stands from riparian ecosystems. Restoration initiatives should target native species that are not negatively affected by allelopathy.     

吉林省林木引种成就及今后发展设想

本文从用材、绿化、经济树种等角度阐述了吉林省林木引种取得的成就,并对今后的引种工作提出了建议。     

绿色植物生长调节剂GGR推广机制的探讨

根据湖南省推广绿色植物生长调节剂的多年实践 ,总结出一条使这一高新科技成果转入试验、示范、推广以及成果不断充实完善的良性循环运转机制。通过采取宏观调控和市场调节相结合的方法 ,建立起上下相连、左右相通的系统的服务保障体系 ,初步形成了试验、示范、销售、科普宣传和人才培养为一体的良性循环。基本上达到了建全体系、培养人才、建立示范、全面应用、促进科技进步的目的。     

外来入侵杂草对广州市白云山的危害及其防治策略的探讨

本文分析了广州市白云山风景区分布的有害外来杂草的种类及对风景区产生的危害，并对如何防治的策略进行了初步的探讨。     

盐胁迫对木槿属两个外来种质生长及叶绿素含量影响

采用盆栽试验,研究了不同质量分数的NaCl胁迫对木槿属两个新引进植物Hibiscus‘Moy grande’、H.dasycalyx高生长、干物质量、根冠比及叶绿素含量变化等指标的影响。结果表明:4 g/kg盐处理水平时,两种材料的高生长量均与对照无显著差异,H.‘Moy grande’的干物质量积累较对照略有下降,H.dasycalyx干物质量积累则受到显著抑制(P﹤0.05);根冠比测定数据表明盐胁迫对两种材料地上部分的生长抑制强于对根系生长的抑制;盐胁迫下两种材料叶绿素a、叶绿素b含量变化趋势与单位质量叶片叶绿素含量的变化相似,均有不同程度的升高。生长指标分析结果表明H.‘Moy grande’对NaCl胁迫的抗性强于H.dasycalyx。     

西藏外来林业有害生物的发生与防范

经过分析西藏的气候和生态环境以及现有森林健康状况,得出结论:外来林业有害生物传入风险极大,适宜定殖的种类繁多。同时介绍了传入西藏的外来林业有害生物主要种类、发生特点、危害程度,入侵途径和载体,提出防范措施。     

土壤重金属污染的植物效应

指出了土壤重金属污染对环境、农业生产及人的健康会造成危害,已引起环保部门的重视。我国对这方面的研究开展较迟,系统性较差,从土壤重金属来源、危害,特别是植物吸收、运转、伤害机理上进行了系统地分析。