Investigation and Hazard Assessment of Invasive Alien Plants on the Campus of Tongren University

[Objectives]The paper was to investigate and assess the species,distribution and hazard status of invasive alien plants on the campus of Tongren University.[Methods]A survey was conducted using line survey method,and the risk assessment index system of invasive alien plants was established by analytic hierarchy process(AHP).[Results]There were 11 species of invasive alien plants on the campus of Tongren University,belonging to 8 genera and 5 families.There were 6 species of invasive alien plants belonging to Asteraceae,accounting for 54.55%of the total.In terms of the origin of invasive plants,most of them were native to North America and Europe,accounting for 27.27%of the total.In terms of harmful level,there were no high-risk invasive plants on the campus of Tongren University,but Alternanthera philoxeroides had the highest score and was the most harmful.[Conclusions]The present situation of alien plant invasion on the campus of Tongren University is closely related to the ecological environment of the campus.It is suggested to strengthen the management of campus plants,focus on the prevention and control of A.philoxeroides,and carry out regular investigation of invasive alien plants on campus to ensure the ecological safety of the campus.

A risk assessment system for alien plant bio-invasion in Xiamen,China

Bio-invasion has caused serious ecosystem damage and enormous economic losses in China,and it has been the greatest factor to island bio-diversity reduction.Xiamen,as an important seaport with a relatively high conservation value,is particularly vulnerable to bio-invasion for its typical island ecosystem as well as frequent human-made disturbance.As a result of field surveys,literature review, and consultation with experts,a list of 67 alien plants identified as major invaders(12 species)and emerging invade...

Monitoring River Restoration Efforts: Do Invasive Alien Plants Endanger the Success? A Case Study of the Traisen River

River restoration activities are challenging for the native vegetation and the colonization process. The development of invasive alien plant species (IAS) as well as the development of the pioneer vegetation cover and seed bank were observed in one year prior to construction of a new river bed and within the first two years after construction, along the downstream section of the river Traisen in Austria. One year after completion of the new river channel, the occurrence of IAS above ground decreased while the occurrence of target species increased. Furthermore, no seeds of IAS were detected in the new river bed as a result of proper management of soil movement. Despite the positive impact on the abundance of IAS, the restoration project of the river Traisen shows that the fact that such a restoration activity is a disturbance event must be taken into consideration already during the planning process. Supporting the competitiveness of native plant species is an important tool for reducing the danger of establishment of invasive alien species.

Investigation and Analysis of Alien Plants in the Scenic Spot Chengbi Lake

A comprehensive survey and analysis of alien invasive plants at the scenic spot Chengbi Lake was conducted by combining route investigation with interviews and quadrat sampling.There were 21 families,33 genera and 42 species in the scenic spot Chengbi Lake.Among them,herbal plants accounted for 69%.The Compositae and Amaranthaceae families were the most frequent,represented by 18 species in total;and 36 species of these alien invasive plants originated from America,accounting for 85.7% of the total.Fifty-seven percent of the species were introduced as ornamental plants.Seven of them were severely harmful,including Wedelia trilobata,Eupatorium odoratum,Lantana camara,Mirabilis jalapa,Solanum erianthum,Ipomoea cairica and Alternanthera philoxeroides.Strategies to increase defensive awareness,reinforce ecological protection,regulate species introduction and improve supervision mechanisms are discussed.

Diversity, Invasion Status and Usages of Alien Plant Species in Northeastern Hilly State of Tripura: A Confluence of Indo-Barman Hotspot

The present study has explored the first authentic catalogue of the alien flora of the foot Himalayan hilly region along with their diversity, uses, various ecological aspects and invasion status. Environmentally similar south and tropical American aliens are higher in numbers in this region. A total of 216 plant species under 158 genera belonging to 58 families have been compiled in this catalogue. This alien flora occupies ~14.5% of the state flora, while 3.47% is invasive. Families having a large number of alien species are Asteraceae followed by Caesalpiniaceae and Solanaceae. Most of the alien species (61.57%) are of American origin followed by Asia (15.28%) and African continent (12.04%). Life form analysis shows that herbs (42.6%) are dominated alien. Among all the aliens, 67 species are used as ornamental plant, followed by 50 medicinally useful plants. In the state neutralized aliens are (36.57%) followed by invasive alien (24.07%). The present study also reports five alien species for the first time from the study site. This base line study would be the foundation for further advance studies on the invasion ecology and for the future assessment and management of invasive species in this biodiversity rich zone. Present work obviously helps in the agricultural sector of the state as well as the country and gives a clue for further introduction of new species in the country.

Impacts of road on plant invasions in the Middle Mountain region of central Nepal

Biological invasion is triggered by human development activities such as the construction and expansion of road networks.Road verges serve as important habitats and corridors for the distribution of invasive alien plant species(IAPS)between geographically distant habitats.However,the trajectory of plant invasion and the data regarding the impact of roads on IAPS distribution are relatively poor in Nepal.Here,we surveyed two road types(main roads and feeder road)in the Middle Mountain region of central Nepal in order to investigate how different road types are driving the dispersal of IAPS along road verges and the adjacent natural habitats.Systematic sampling was conducted at ca 2.5 km intervals along the roads.At each sampling site,paired plots(25 m×4 m)were sampled:one adjacent to and along the road,and another 20 m away and parallel to it in the interior habitat.Our results revealed that the main road verges had a higher cover(33%)and a larger number of IAPS(14 species)than the feeder road(25%;10 species).The IAPS cover and richness were significantly higher along verges than in the adjacent interior habitats for both road types,indicating that roads are contributing as corridors for the dispersal of IAPS in the Middle Mountain areas of central Nepal.Further,elevation,tree canopy,and disturbances(grazing/mowing/trampling)were found to be the key factors that determine spatial distribution of IAPS along road verges.We emphasize that regular monitoring of vegetation along the road verges can help with the early detection and control of potential IAPS in the region before they become problematic.

Species and Distribution Characteristics of Alien Invasive Plants in Garden Greenbelt of Shijiazhuang City

[Objectives]The paper was to investigate the garden greenbelt in 30 sample plots such as parks,roads,communities,etc.in Shijiazhuang City.[Methods]The species,abundance and frequency of weeds in the greenbelt of public gardens were recorded through point-line-surface investigation,and typical plants were sampled.[Results]There were 56 species of alien invasive plants in garden greenbelts of Shijiazhuang City,belonging to 44 genera and 20 families.In terms of life form,herbaceous plants were absolutely dominant,accounting for 92.8%of the total.The most alien invasive plants were native to America,accounting for 66.1%of the total.In terms of introduction path,the plants introduced artificially and unintentionally accounted for almost half.The species and quantity of alien invasive plants were related to the size of greenbelt area,the length of the build time of the surveyed plot,the composition structure of greenbelt and the level of green management and protection.There was larger distribution of alien invasive plants in the sample plots with large greenbelt area,long build time,herbaceous-dominated greenbelt and low level of green management and protection.Among the 56 alien invasive plants,3 plants were toxic.From the perspective of invasiveness,the alien invasive plants in the garden greenbelt of Shijiazhuang City could be divided into 5 levels:invasive alien species of malignant consequences,invasive alien species of severe consequences,invasive alien species of partial consequences,invasive alien species of average consequences,and invasive alien species to be observed.[Conclusions]This study will provide a reference for the prevention and control of alien plant invasion,and lay a foundation for the prevention and control of existing invasive plants.

Survey and Analysis on Alien Invasive Plants of Jinziling Scenic Spot in Pingle County

According to the field survey of alien invasive plants of Jinziling,there were 23 kinds of alien invasive plants in the scenic spot.Species with the comprehensive dominance degree higher than 10% were as follows: six kinds of Asteraceae: Bidens pilosa,Aster subulatus,Ageratum conyzoides,Conyzai canadens,Parthenium hysterophorus,and Conyza sumatrensis; two kinds of Gramineae: Axonopus compressu,Eleusine indica; two kinds of convolvere: Ipomoea nil,Ipomoea purpurea; two kinds of Fabaceae: Cassiae tora,Medicago hispida; one kind of Verbenaceae: Lantana camara; one kind of Euphorbiaceae: Euphorbia hirta.In total,there were 14 kinds of alien invasive plants.In this survey,the dominant species of invasive plants were obtained by statistical analysis of the composition and distribution of the invasive plants,and the invasion trend was predicted,so as to take effective and economical management and control measures.

Contrasting responses of native and alien plant species to soil properties shed new light on the invasion of dune systems

在陆地生态系统中,沿海沙丘特别容易受到外来植物的入侵。许多研究将沙丘生境的入侵归因于人为因素,但对土壤性质和植物性状在植物入侵中的作用却知之甚少。本研究考察了沙丘系统土壤特征与外来植物入侵的关系,重点研究了土壤养分、土壤盐分和植物功能特征之间的相互作用。研究地点是马拉诺和格拉多泻湖(北亚得里亚海)的沙质堰洲岛。根据沙丘系统生态梯度上的主要生境(前沙丘、后沙丘和盐沼),在10个区域内选择100个地块(4 m×4 m)。在每个地块中记录所有植物物种的发生和丰度,并收集一个土壤核。对每个土壤样品进行土壤质地、电导率(代表土壤盐分)、有机碳和氮含量分析,并与本地和外来植物的种类数和覆盖度相关联。分析外来和本地物种主要的生殖功能和营养功能性状在生境中的变化。研究结果表明,土壤性质对外来物种库和本地物种库的影响不同,与植物整体多样性密切相关。在后沙丘(最易入侵)的生境中,高的土壤导电性限制了外来物种的数量,但土壤有机碳含量随着外来植物丰度的增加而增加,这也表明植物入侵与土壤之间存在潜在的反馈过程。只有在后沙丘生境中,随着环境条件的改善和植物竞争的加剧,本地植物和外来植物的功能性状谱有显著的趋同。本研究结果表明,在恶劣条件下,只有本地特有植物才能茁壮成长,而在中等条件下,土壤特性梯度与植物特性协同作用,抑制/促进外来植物丰富度。

云南九大高原湖泊湖滨带入侵植物物种组成与分布特征

湖滨带植物多样性是湖滨带生态系统维持稳定的关键,入侵植物的出现破坏湖滨带生态平衡,对湖滨带生态安全造成威胁。为揭示云南九大高原湖泊湖滨带入侵植物组成与分布特征,基于文献报道及野外踏查,整理得到云南九大高原湖泊湖滨带外来入侵植物名录,并对其种类组成、原产地、生活型、分布特征、区系类型、繁殖特征进行了分析。结果显示,云南九大高原湖泊湖滨带有外来入侵植物64种,隶属于23科52属。从种类组成上看,外来入侵植物多为菊科(Asteraceae)和苋科(Amaranthaceae);从分布特征上看,滇池湖滨带入侵植物分布最多,泸沽湖湖滨带入侵植物分布最少;从原产地上看,超过50%的入侵植物来自美洲;从生活型上看,外来入侵植物几乎均为草本植物,且以一年生草本植物居多;从物种分布上看,白车轴草Trifolium repens、凤眼莲Eichhornia crassipes、土荆芥Dysphania ambrosioides、喜旱莲子草Alternanthera philoxeroides分布最广;从区系类型上看,九大高原湖泊湖滨带外来入侵植物科和属的区系类型均具有明显的广布与泛热带分布特征;从繁殖特征上看,外来入侵植物花期集中于7-10月,果实类型多为被毛瘦果。研究表明,云南九大高原湖泊湖滨带入侵植物较为多样,与同区域数据比对后发现九大高原湖泊湖滨带入侵植物种数有所增加。不同湖滨带入侵植物种数的差异可能与海拔、温度和周边人口数量有关,较高的海拔,较低的年均温以及较少的周边人口数量都有利于减少湖滨带入侵植物种数。研究结果将为高原湖泊湖滨带生态系统风险评估和防控部署提供理论基础。

济宁市外来入侵植物的区系成分及多样性分析

为弄清济宁市外来入侵植物的区系成分及多样性成因,减少外来入侵植物对济宁市生物多样性的影响提供理论依据。在已知济宁市外来入侵植物种类组成的基础上,通过实地调查对其科、属、种的分布区类型进行了分析,探讨了外来入侵植物多样性的成因。结果表明:在区系组成上,济宁市外来入侵植物的热带性成分占绝对优势,其比例在科、属、种水平上分别为83.33%、52.55%和53.61%。入侵种所在科、属,常广域分布,但入侵种原产地分布范围却不大,并倾向于集中在某些特定区域(如美洲、狭义地中海区)。

基于机器学习的外来入侵植物叶片图像识别方法

为了有效避免外来入侵植物打破当地植物自身的生长环境,提出一种基于机器学习的外来入侵植物叶片图像识别方法.通过基于指数变量的自适应扩张图像滤波算法对外来入侵植物叶片图像滤波处理.构建金字塔卷积网络,提取轮廓纹理特征并且融合,采用softmax函数获取最终的外来入侵植物叶片图像识别结果.通过实验测试证明,所提方法可以有效降低外来入侵植物叶片图像识别时间,提升识别结果准确性,同时所提方法可以在各种应用场景中提供高效、准确的图像处理和识别能力.

基于改进MobileNet的轻量级外来入侵植物识别模型研究

外来入侵植物防治的首要任务是准确识别入侵植物种类,然而外来入侵植物种类繁多,存在类间同质和类内异质现象,给技术人员甄别与防治外来入侵植物带来了挑战。为了准确、实时和高效地识别外来入侵植物,本文提出基于改进MobileNet的轻量级外来入侵植物图像识别模型(MobileNet-LW)。以专业人员鉴定得到的113种11 628幅外来入侵植物图像作为研究对象,并按照6∶2∶2的比例划分训练集、验证集和测试集。通过Retinex、旋转和高斯噪声等方法对图像进行数据增强。为了减少类间同质现象对模型误检的影响,在模型MobileNet基础上添加了SE通道注意力机制和深度连接注意力网络,提高网络对关键特征的提取能力。为了降低模型计算消耗和内存消耗,采用通道剪枝方法对网络瘦身;为了弥补剪枝后造成模型准确率降低,采用教师网络-助教网络-学生网络的形式对剪枝后的网络进行知识蒸馏,学生网络通过软知识的学习来提高识别外来入侵植物的准确率。通过消融试验测试模型的性能,利用平均准确率、平均召回率和平均F1值3个评价指标,对现阶段经典模型与改进后模型MobileNet-LW所获得的识别结果进行评价。消融试验结果显示,在相同数据集条件下,所有改进点对模型的性能都有所提升,且改进后算法在外来入侵植物图像识别中准确率提高了5.4百分点,模型参数量减少了约53%;模型对比试验表明,EfficentNet、DBTNet、ResNet-101、ConvNext和MobileNet-LW 5个模型平均准确率分别为72.3%、74.9%、76.1%、79.7%和86.1%,表明改进后的网络提高了外来入侵植物的识别准确率。基于改进MobileNet的轻量级外来入侵植物识别模型对113种外来入侵植物识别具有较高的准确率,且模型具有轻量化特点。

缙云县外来入侵植物调查及分析

通过对缙云县18个乡镇72个踏查点进行实地踏查,并结合文献资料,研究了缙云县外来植物的结构组成以及分布状况。结果显示,缙云县已存在的外来入侵植物共有59种,隶属25个科,48个属。其中,菊科是缙云县外来植物的主要类群,共20种,占总种数的33.9%。此外,46种原产自美洲,占总数的78.0%。分布最广外来入侵植物是斑地锦、垂序商陆、凤仙花、空心莲子草、三叶鬼针草、胜红蓟、小蓬草。该研究为控制缙云县外来入侵物种提供数据支持,有利于制定对外来植物的防控策略,为缙云县的生态多样性和物种多样性保护提供理论依据和数据参考。

人类活动对河岸湿地植物群落的影响

人类活动干扰是河岸带外来植物侵入的主要原因之一.选取唐河县乡村段和城市段,对比研究河岸湿地外来植物群落特征,旨在探明不同类型人类活动对外来植物的影响程度.研究发现,6个处理中乡村段河岸上乡土植物的比例最高(65.38%).乡村段的乡土植物比城市段多,乡村段的入侵植物明显低于城市段.无论是乡村段还是城市段,乡土植物优势度都最高,乡村段河岸的乡土植物优势度高于城市段,而乡村段河岸外来植物的优势度明显低于城市段,乡村段河岸的入侵植物优势度也显著高于城市段.在乡村段的外来植物中,多年生旱生草本植物的比例最高(38.29%),而在城市段的外来植物中,一年生中生草本植物的比例最高(29.45%).乡村段与城市段的本土植物相似度最高(0.823),其次是乡村段与城市段的外来植物(0.692).随着人类活动干扰强度不断增加,物种的更替变化导致不同区域的植物群落构成呈现出很大的差异,降低了区域之间植物物种的相似性.唐河县段河岸带外来植物种类的构成特点,反映出人类活动对河岸带外来植物干扰逐渐扩大的趋势,包括快速城市化和农业活动等.

外来入侵植物小蓬草发生现状及防治方法研究综述

外来入侵植物小蓬草(Erigeron canadensisL.)传播扩散速度极快,在我国各省市均有发生,包括东北、华北、西北、西南、华中、华东以及华南等区域,常发生在荒地、田间、路边等,是一种发生率极高的杂草,目前已被列入我国入侵物种第三批名单。作者详细整理小蓬草在我国的入侵途径、发生现状及防治方法,科学分析小蓬草的危害和价值,并提出“三加强,一科学”的防治对策建议。该文通过对小蓬草发生现状及防治方法科学分析,深入研判,旨在为外来入侵植物的科学治理提供参考。

中国外来入侵水生植物及其在污染水体生态修复中的应用进展

随着社会经济与工农业的快速发展以及人类活动加剧,外来生物以及以氮、磷为主的富营养化和重金属、有机物等污染物正不同程度威胁中国水生态安全、生物多样性及国民经济高质量发展。相对价格高、工程量大和二次风险高的物理和化学措施,以水生植物为核心的生物-生态法在水生态修复中备受青睐和广泛应用。中国外来入侵水生植物物种多,虽然这些物种入侵程度不同,但其分布相对集中在东部平原区和云贵高原区。过去30年来,中国在防控外来入侵水生植物的同时,挖掘凤眼蓝〔Eichhornia crassipes(Mart.)Solms.〕、喜旱莲子草〔Alternanthera philoxeroides(Mart.)Griseb.〕和大薸(Pistia stratiotes Linn.)等在污染水体生态修复方面的功能和实际应用,取得了一定进展,发现外来入侵水生植物在不同水体和不同污染物类别间有一定的修复差异,且部分物种表现出与本土植物间的比较优势;对水体污染物的去除机制主要包括植物吸收与同化、根系分泌物与根际微生物互作以及植物降解与挥发等。本文全面梳理了中国外来入侵水生植物物种及地理分布,分析了凤眼蓝、喜旱莲子草和大薸等典型外来入侵水生植物修复污染水体的效果与机制,指明外来入侵水生植物的重要研究方向,认为未来在利用外来入侵植物进行水生态修复时,应兼顾防控和资源高值化综合利用及科普教育的协同工作。

Changes in Soil Biota Resulting from Growth of the Invasive Weed, Ambrosia artemisiifolia L.(Compositae), Enhance Its Success and Reduce Growth of Co-Occurring Plants

Exotic plant invasion presents a serious threat to native ecosystem structure and function. Little is known about the role of soil microbial communities in facilitating or resisting the spread of invasive plants into native communities. The purpose of this research is to understand how the invasive annual plant Ambrosia artemisiifolia L. facilitates its competition capacity through changing the structure and function of soil microbial communities. The soil characteristics of different areas invaded by A. artemisiifolia were examined. Greenhouse experiments were designed to assess the effect of A. artemisiifolia invasion-induced changes of soil biota on co-occurring plant growth, and on the interactions between A. artemisiifolia and three co-occurring plant species. The results showed that the soil organic C content was the highest in heavily invaded sites, the lowest in native plant sites, and intermediate in newly invaded sites. Soil available N, P and K concentrations in heavily invaded site were 2.4, 1.9 and 1.7 times higher than those in native plant soil, respectively. Soil pH decreased as A. artemisiifolia invasion intensity increased, and was lower in invaded sites（heavily invaded and newly invaded） than in native plant sites. The soil microbial community structure was clearly separated in the three types of sites, and A. artemisiifolia invasion increased anaerobe, sulfate-reducing bacteria and actinomycete abundance. Soil biota of invaded sites inhibits growth of co-occurring plants（Galinsoga parvifloraCav., Medicago sativa L. and Setaria plicata（Lam.） T. Cooke.） compared to soil biota from un-invaded sites, but facilitates A. artemisiifolia growth and competition with co-occurring plants. A. artemisiifolia biomass was 50-130% greater when competing with three co-occurring plants, compared to single-species competition only（invasion by A. artemisiifolia alone）, in heavily invaded soil. Results of the present study indicated that A. artemisiifolia invasion alters the soil microbial community in a way that favors itself while inhibiting native plant species, with measurable effects on performance of co-occurring plants.