南宁的外来入侵植物

根据野外调查及文献资料的整理,对南宁地区外来入侵植物的种类组成、危害现状、原产地、生活型和入侵生境等进行了分析。结果表明,南宁现有外来入侵植物72种,隶属于25科55属,其中菊科植物19种,禾本科9种,苋科和茄科各6种,分别占总种数的26.4%、12.5%和8.3%。就危害程度而言,已造成严重危害的种数达12种,中等危害有17种,轻度危害有43种。从原产地分析来看,源自美洲的入侵植物多达62种,占总种数的86.1%,其次为源自非洲(5种)、地中海(3种)和欧洲(2种)的植物。这些外来入侵植物中,草本植物种类最为丰富(57种,占种总数的79.2%),其次为灌木(10种,13.9%)和乔木(3种,4.2%)。此外,南宁外来入侵植物的种类组成与广州、澳门和厦门等地的共有种数相对较多,而与青岛、北京和沈阳等地的共有种数较少。同时对外来入侵植物的防控对策进行了简要分析。     

我国对3种外来入侵植物的利用

主要介绍了我国在防治生物入侵时,对水葫芦、紫茎泽兰、互花米草等入侵植物的综合利用.     

广州外来入侵植物

根据野外调查及相关文献资料,初步探讨了广州市外来入侵植物的种类组成、分布生境、生长特性、危害以及来源.结果表明:广州市现有外来人侵植物73种,隶属于27科59属,其中菊科(19种)、禾本科(8种)、豆科(7种)和苋科(7种)植物占了入侵植物总种数的56.2%.生活型分析发现,在广州有分布的外来入侵植物中,陆生草本植物最多(58种),其次为灌木(10种)、水生草本(3种),乔木种类最少(2种),它们主要生长在人类干扰比较频繁的低海拔地区.另外,基于对外来入侵植物目前在野外的生长和分布状况等生态学特性进行分析,可大致将它们对本地生物多样性危害程度分为3级,其中危害严重的有11种,危害中等的有25种,危害较轻的有37种.从原产地分析来看,61种来自于热带美洲地区,占广州外来入侵植物总种数的83.6%.与国内其他地区外来入侵植物进行比较发现,广州和广西共有种数最多,有62种,然而,对已经造成严重危害的外来植物种类,在数量上广州与香港、深圳和广西相同种类较多,分别有8种、7种和6种.对广州市目前外来植物的入侵风险(潜在威胁)的评估结果表明,对一些在其它地区已经造成严重危害的外来植物,应当加强监控,防止入侵扩散并造成重大生态灾难.还对广州市外来植物入侵的主要途径及防治策略做了简要分析和说明.     

植物外来种入侵及其对生态系统的影响

对植物外来种的入侵及生态系统的影响进行综述与分析,植物入侵多种因子的影响,可分为外因和内因两类,植物外来种对生态系统的影响主要体现在生产力,土壤营养,水分,干扰体制,群落的结构和动态等方面,在管理外来种时,需对外来种的特性和影响因子进行系统的观察研究,采用机械法,化学方法和生物控制法等综合办法控制植物的入侵,引进植物引来种时,要对引进种的行为特性进行了调查研究,注意其安全性。     

植物功能性状与外来植物入侵

揭示影响外来植物入侵性的功能性状及其生态机制是入侵植物生态学的核心任务之一。本文综述了植物功能性状与外来植物入侵性的研究进展, 通过分析植物功能性状对外来植物入侵的贡献以及外来植物的不同入侵阶段对其功能性状的需求, 探讨植物功能性状与外来植物入侵的相关性及其入侵机理。迄今研究较多的影响外来植物入侵性的功能性状主要包括形态性状、生长性状、生理性状、繁殖性状、种子性状、克隆性状、表型可塑性和遗传变异等。这些功能性状对外来植物入侵的贡献随着入侵阶段的不同而变化。在传播到达阶段, 种子性状对入侵具有重要影响; 在定居建群阶段, 与植物抗逆性和适应性相关的生理性状和繁殖性状发挥主要作用; 在扩散入侵阶段, 克隆性状和影响植物竞争能力的生理性状对植物成功入侵具有重要贡献。由于植物入侵性是其功能性状和环境因素互作的结果, 且功能性状的作用随环境因素和入侵阶段不同而异, 因此, 结合外来植物入侵阶段, 并考虑功能性状与环境因子的互作, 是入侵生物学中植物功能性状研究的发展趋势。     

京津冀外来入侵植物

基于文献报道和分类学考证, 首次全面、系统而又完整地整理了京津冀近20年报道的46科141属210种外来入侵植物种类及信息。经过分析并校正分为国产种和入侵种两大类。国产种又包括一般国产种22科39属39种、国产逸生类9科13属13种、国产归化类3科3属4种、国产入侵类1科1属1种; 外来种包括实则在京津冀没有达到入侵的温室及露地栽培类8科9属9种、外来逸生类12科32属36种、外来归化类10科19属20种、外来有待观察类6科6属6种, 真正对京津冀构成入侵的外来植物20科48属82种。根据京津冀目前标本数目及采集时间、京津冀报道文献次数及具体内容描述, 结合国家入侵等级及京津冀部分地区的实地考察情况, 对82个入侵种进行入侵级别划分, 分析并讨论了京津冀外来入侵物种的组成、原产地、分布特征、生活型和入侵途径以及京津冀外来入侵植物的危害现状, 并提出防治及管理措施。     

南四湖湿地外来入侵植物

南四湖是我国重要的淡水湖泊湿地之一。为阐明南四湖湿地外来植物的现状及入侵规律, 为湿地生态系统的重建、生物多样性的保护和湿地资源开发等提供指导, 通过野外调查和参考有关文献资料, 对南四湖湿地外来植物进行了较为深入的研究, 并与青岛、昆嵛山、滨州沿海三地作了比较。结果表明, 南四湖湿地外来入侵植物有41种, 隶属19科35属; 以菊科和豆科为优势科; 外来入侵物种中热带来源与温带来源比例相当, 人为引入导致的外来入侵植物高达39%。南四湖与沿海三地相比, 沿海三地外来入侵植物的种类均比南四湖湿地多, 其中以经济最发达的青岛种类最多; 青岛外来入侵植物中有35种在南四湖湿地未发现; 南四湖湿地的特有外来入侵植物有5种, 体现出湿地外来入侵植物水生特性。群落相似性分析表明, Jaccard指数和Sorenson指数呈现的规律一致, 南四湖与滨州的相似性最高, 其次为昆嵛山, 与青岛的差异最大。通过分析南四湖湿地外来入侵植物种类和分布规律, 提出了相应的防治对策。     

南四湖湿地外来入侵植物

南四湖是我国重要的淡水湖泊湿地之一。为阐明南四湖湿地外来植物的现状及入侵规律,为湿地生态系统的重建、生物多样性的保护和湿地资源开发等提供指导,通过野外调查和参考有关文献资料,对南四湖湿地外来植物进行了较为深入的研究,并与青岛、昆嵛山、滨州沿海三地作了比较。结果表明,南四湖湿地外来入侵植物有41种,隶属19科35属;以菊科和豆科为优势科;外来入侵物种中热带来源与温带来源比例相当,人为引入导致的外来入侵植物高达39%。南四湖与沿海三地相比,沿海三地外来入侵植物的种类均比南四湖湿地多,其中以经济最发达的青岛种类最多;青岛外来入侵植物中有35种在南四湖湿地未发现;南四湖湿地的特有外来入侵植物有5种,体现出湿地外来入侵植物水生特性。群落相似性分析表明,Jaccard指数和Sorenson指数呈现的规律一致,南四湖与滨州的相似性最高,其次为昆嵛山,与青岛的差异最大。通过分析南四湖湿地外来入侵植物种类和分布规律,提出了相应的防治对策。     

湛江市外来植物入侵状况

[目的]了解湛江市外来入侵植物的种类特征、生活型、起源和危害情况等,对制定预防和控制管理措施提供参考。[方法]以野外调查为主,结合文献资料、网络资源以及标本数据,确定湛江市外来入侵植物的种类、生活型、原产地、引入途径,并进行评估及划分危害等级。[结果]湛江市现有外来入侵植物共112种(含变种),隶属于37科89属,其中,菊科(21种)、禾本科(13种)和豆科(13种)为种类较多的3个科,三者合计占湛江市外来入侵植物总种数的41.96%。湛江市外来入侵植物中以草本植物居多(98种),占入侵植物总数的87.50%。入侵植物主要来源于美洲,共82种,占总种数的73.21%;且55.36%(62种)的入侵植物为有意引入。从危害等级看,外来入侵植物中恶性入侵种(1级)23种,严重入侵种(2级)35种,局部入侵种(3级)21种,一般入侵种(4级)15种,有待观察种(5级)18种。[结论]湛江市的外来入侵植物种类繁多,这与湛江独特的地理位置以及日趋频繁的人类活动息息相关,应当加强监管与防范,及时对外来物种进行治理。     

福建外来入侵植物初步研究

经野外调查和整理分析文献资料,初步认定福建省外来入侵植物并已归化的种类约73种,分属于29科,其中菊科种类最多,有16种。从来源看,来自美洲的有59种,占80.82%。入侵植物中包括6种2003年国家环保总局公布的首批外来入侵物种。文中还对这些外来入侵植物的危害、入侵途径及其防治对策进行讨论。     

Clidemia hirta Invasion at the Pasoh Forest Reserve: An Unexpected Plant Invasion in an Undisturbed Tropical Forest1

Clidemia hirta is a highly invasive shrub in tropical forests throughout the world, but has had little success invading mainland sites and undisturbed forests. In the early 1990s, this plant was found to have invaded an unexpected site, an undisturbed continental tropical forest at Pasoh, Peninsular Malaysia. In 1997, a study was conducted of the C. hirta population at the Pasoh Forest Reserve. A demographic survey of the 50–ha long–term research plot at Pasoh located 1002 C. hirta individuals, 69 of which were reproductive at the time of the study. All but 8 individuals were located in high light gaps or gap edges. Relative growth rates were significantly higher in gaps and gap edges than in the understory, and no reproductive individuals were found in the understory. Mean plant size and dry biomass density increased steadily over the course of the study, while the observed mortality rate was 0 percent over two months. The biomass density of Clidemia at Pasoh was <500 g/ha at the conclusion of this study, but because the population is confined almost exclusively to high light environments, its density in these sites is much higher. The location of C. hirta plants in gaps was significantly correlated with past disturbance by wild pigs, suggesting that soil disturbance and light availability are essential for their establishment. The implication of this study is that by competing with native species in gaps, C. hirta invasion has the potential to alter forest regeneration at Pasoh. Changing land use practices near the reserve have increased the number of wild pigs, and thus the level of disturbance, which may explain the recent success of C. hirta at Pasoh.     

Relationships among Amphibian Assemblage Structure,Wetland pH,and Forest Cover

A common mesofilter approach to conservation of biological diversity and ecosystem function used in agricultural and urban landscapes is maintenance of wetlands and an undisturbed terrestrial buffer surrounding wetlands. Although it is generally accepted that forest buffers protect wetland-associated biological diversity and ecosystem function, the effectiveness and optimal spatial extent of buffers is still an area of debate. During 2007 and 2008 we surveyed amphibians and environmental conditions associated with 54 depression wetlands on the Delmarva Peninsula of Maryland, USA, to examine the role of forest buffers and wetland characteristics in structuring amphibian communities. Forest cover within a 50-m buffer surrounding wetlands was correlated (r = −0.81) with wetland pH but no other wetland characteristics. Wetland pH, canopy cover, hydroperiod, and adjacent forest cover were important predictors of wetland use by individual amphibian species, with many species more likely to occur at wetlands that dried late in the hydrological year and with open canopies. At least one common species preferred circumneutral pH and several restricted-distribution species preferred lower pH (<5). Contrary to expectations, relationships between species occurrence and adjacent forest cover were negative. Our results suggest that current regulations that provide buffers of 30 m or less do not provide adequate protection of wetland water chemistry but that forest encroachment into wetlands may be a threat to the integrity of amphibian communities and should be the target of monitoring, future research, and management efforts. © 2021 The Wildlife Society.     

There is room for everyone: Invasion credit cannot be inferred from the species–area relationship in fragmented forests

Questions

Land use change, habitat fragmentation and biological invasion represent major drivers of global change that strongly interact to alter ecosystems. Following the breaking apart of forests into smaller fragments or the afforestation of former agricultural lands, biodiversity experiences drastic changes due to species loss and turnover over time. This leads to two important outcomes, namely extinction debt and invasion (colonization) credit, which both reflect the inertia of the system's response to environmental changes. Our study investigated the following questions:

• Is it possible to infer invasion credit from species–area relationship (SAR) residuals both for native and alien plants?
• Is there any trend linked with the degree of habitat fragmentation through time?

     

Plant Diversity, Production, Stability, and Susceptibility to Invasion in Restored Northern Tall Grass Prairies (United States)

This study investigated the relationship among plant diversity, production, stability, and susceptibility to invasion in restored northern tall grass prairies (United States). The experiment consisted of 50 species mixtures fertilized with N or P, at high or low levels. Results from the past 5 years were as follows: (1) aboveground biomass increased and year‐to‐year variability declined with increases in plant species and functional form richness, mostly as a result of substantial increases in minimum biomass (maximum biomass was unaffected). (2) Aboveground biomass and biomass stability increased when the species in the mixture had: (a) high relative growth rates, root density, root surface area per unit of root biomass, uptake rates of N or P per unit of root surface area, and N use efficiency and (b) low root to shoot ratio. (3) Invasion of nonseeded species declined with increases in plant species and functional form richness. (4) The results from this experiment did not provide a single specific criterion for selecting an optimal species mixture. However, if the objectives of the restoration were simply to achieve an aboveground biomass variability that is less than that of growing‐season precipitation, then the seed mixtures need to have a minimum of nine species and three functional forms.     

Invasion biology,ecology, and management of Frankliniella occidentalis in China

Frankliniella occidentalis is an economically important invasive pest worldwide, which can damage various horticultural crops and ornamental plants. F. occidentalis was first intercepted in Kunming, Yunnan province in 2000, and first reported to establish a population in Beijing, China in 2003. Since then, this pest is currently distributed across tens of provinces in mainland China and cause increasingly serious damage and loss. To control this pest, invasion biology, monitoring, and integrated pest management have been generally and intensively studied for 15 years in China. Furthermore, western flower thrips (WFT) as an important invasive insect pest, the research achievements on WFT has contributed to the promotion of technological innovation and development for invasive alien species management strategies and techniques in China. This review provides an overview for research on the biology, ecology, prevention, and management of this pest during 15 years in China. Meanwhile, China's “4E action” strategy on F. occidentalis is also discussed in this review.     

Exotic Herbivores as Drivers of Plant Invasion and Switch to Ecosystem Alternative States

This paper discusses the evidence of the way in which coupled herbivore and plant invasions altered the structure and functioning of ecosystems in central Chile, and compares these patterns to results from other Mediterranean ecosystems around the world. In pre-Columbian times, sclerophyllous matorral forests largely covered mediterranean Chile. Remnants of the original, continuous matorral can now be found only on relatively humid slopes of the Coastal Range. In the Intermediate Depression, a long central valley, it has been replaced by extensive savannas dominated by the exotic Acacia caven, whereas the matorral remains on dry slopes as isolated shrub clumps. Experimental work suggests that introduced cattle have played a major role in promoting the shift to Acacia savanna, whereas introduced European rabbits prevent the recolonization of clearings by matorral on the slopes. As in other regions of the world, the loss of woodlands in Chile is likely to have resulted in reduced carbon storage capacity and nutrient recycling, and in increased erosion and climatic aridity within the region. Numerous exotic herbs and grasses now dominate the open areas, and experiments indicate that the dry conditions in the absence of woodland cover in combination with loss of soil fertility and severe grazing by introduced mammals has pushed the competitive balance from native to exotic species. These changes are probably very difficult to reverse. Even if grazing is drastically reduced, drought may prevent the recovery of matorral species in much of the region. However, recent theoretical work suggests that if such grazer reduction is timed to coincide with wet El Niño episodes, recovery of the original woodlands may be triggered.     

广州的外来植物

该文分析了127种广州外来植物的种类及其生长型、原产地、现状、生境和季节变化。结果表明:具有较强繁殖能力的草本、灌木和藤本植物以及一些世界广布或热带性科属的植物和原产美洲、非洲的一些植物具有较强的入侵能力;受人为干扰较强的路边、荒地、池塘、果园、菜园和人工林容易为外来植物入侵,而人为干扰较少的自然生境则不易为外来植物入侵。此外,文章对物种的入侵性和生境的入侵性问题进行了讨论,认为这实际上是一个问题的两个方面,物种的入侵性总是与被入侵的生境联系在一起并相互影响的。     

西双版纳外来植物的物种多样性、用途和生态危害的初步研究

在西双版纳282科近5000种高等植物中,有外来植物153科1127种,其中药用、花卉和可食用种类分别占39．0％、33．9％和20．3％。外来植物集中分布在植物园和当地居民的庭院中,并沿道路向外扩散。外来植物丰富了西双版纳的物种多样性,促进了地方经济发展,但少数杂草类入侵物种的生态危害很明显。     

Logging and Edaphic Factors in the Invasion of an Asian Woody Vine in a Mesic North American Forest

Factors contributing to an invasion of the Asian woody vine Celastrus orbiculatus in a mesic forested Massachusetts (USA) sanctuary were investigated. Planting germinated C. orbiculatus seeds in the field revealed that, although they tolerate a wide range of conditions, seedlings grow largest in moist circumneutral soil under high irradiance. A study of naturally occurring vines in a logged forest suggested that C. orbiculatus invaded two years after harvest, and invasion may have been triggered by logging disturbance. Vine stems were more abundant on former logging roads than in surrounding selectively logged areas. Former logging roads had a significantly higher soil pH than surrounding areas and, due to the direction of construction, a significantly more southerly aspect. Fourteen years after harvest, logging roads continued to provide this aggressive exotic with superior habitat for establishment and growth.