scholarly journals Seed dispersal networks in the Galápagos and the consequences of alien plant invasions

2013 ◽  
Vol 280 (1750) ◽  
pp. 20122112 ◽  
Author(s):  
Ruben H. Heleno ◽  
Jens M. Olesen ◽  
Manuel Nogales ◽  
Pablo Vargas ◽  
Anna Traveset
Keyword(s):  
Seed Dispersal ◽  
Time Lag ◽  
Habitat Type ◽  
Plant Invasions ◽  
Psidium Guajava ◽  
Fruit Production ◽  
Alien Plants ◽  
Alien Plant ◽  
Plant Introductions ◽  
The Impact

Alien plants are a growing threat to the Galápagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most dispersed invaders were Lantana camara , Rubus niveus and Psidium guajava , the latter two likely benefiting from an asynchronous fruit production with most native plants, which facilitate their consumption and spread. Lava lizards dispersed the seeds of 27 species, being the most important dispersers, followed by small ground finch, two mockingbirds, the giant tortoise and two insectivorous birds. Most animals dispersed alien seeds, but these formed a relatively small proportion of the interactions. Nevertheless, the integration of aliens was higher in the island that has been invaded for longest, suggesting a time-lag between alien plant introductions and their impacts on seed dispersal networks. Alien plants become more specialized with advancing invasion, favouring more simplified plant and disperser communities. However, only habitat type significantly affected the overall network structure. Alien plants were dispersed via two pathways: dry-fruited plants were preferentially dispersed by finches, while fleshy fruited species were mostly dispersed by other birds and reptiles.

scholarly journals Microbial Communities in the Fynbos Region of South Africa: What Happens during Woody Alien Plant Invasions

Diversity ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 254
Author(s):  
Karin Jacobs ◽  
Tersia Conradie ◽  
Shayne Jacobs
Keyword(s):  
Current Knowledge ◽  
Plant Invasions ◽  
Cape Floristic Region ◽  
Alien Plants ◽  
Microbial Populations ◽  
Invasive Alien Plants ◽  
Alien Plant ◽  
Lack Of Information ◽  
The Common ◽  
Insight Into

The Cape Floristic Region (CFR) is globally known for its plant biodiversity, and its flora is commonly referred to as fynbos. At the same time, this area is under severe pressure from urbanization, agricultural expansion and the threat of invasive alien plants. Acacia, Eucalyptus and Pinus are the common invasive alien plants found across the biome and considerable time, effort and resources are put into the removal of invasive alien plants and the rehabilitation of native vegetation. Several studies have shown that invasion not only affects the composition of plant species, but also has a profound effect on the soil chemistry and microbial populations. Over the last few years, a number of studies have shown that the microbial populations of the CFR are unique to the area, and harbour many endemic species. The extent of the role they play in the invasion process is, however, still unclear. This review aims to provide an insight into the current knowledge on the different microbial populations from this system, and speculate what their role might be during invasion. More importantly, it places a spotlight on the lack of information about this process.

scholarly journals The DIARS toolbox: a spatially explicit approach to monitor alien plant invasions through remote sensing

2018 ◽  
Vol 4 ◽  
pp. e25301
Author(s):  
Carol X. Garzon-Lopez ◽  
Tarek Hattab ◽  
Sandra Skowronek ◽  
Raf Aerts ◽  
Michael Ewald ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Open Source ◽  
New Technologies ◽  
Remote Sensing Data ◽  
Plant Invasions ◽  
Alien Plant ◽  
Practical Applications ◽  
Sensing Data ◽  
The Impact ◽  
Scientific Advances

The synergies between remote sensing technologies and ecological research have opened new avenues for the study of alien plant invasions worldwide. Such scientific advances have greatly improved our capacity to issue warnings, develop early-response systems and assess the impacts of alien plant invasions on biodiversity and ecosystem functioning. Hitherto, practical applications of remote sensing approaches to support nature conservation actions are lagging far behind scientific advances. Yet, for some of these technologies, knowledge transfer is difficult due to the complexity of the different data handling procedures and the huge amounts of data it involves per spatial unit. In this context, the next logical step is to develop clear guidelines for the application of remote sensing data to monitor and assess the impacts of alien plant invasions, that enable scientists, landscape managers and policy makers to fully exploit the tools which are currently available. It is desirable to have such guidelines accompanied by freely available remote sensing data and generated in a free and open source environment that increases the availability and affordability of these new technologies. Here we present a toolbox that provides an easy-to-use, flexible, transparent and open source set of tools to sample, map, model and assess the impact of alien plant invasions using two high-resolution remote sensing products (hyperspectral and LiDAR images). This online toolbox includes a real case dataset designed to facilitate testing and training in any computer system and processing capacity.

scholarly journals Invasive alien plant species in Romania of European Union concern

2021 ◽  
Vol 9 (4) ◽  
pp. 32-44
Author(s):  
Culiţă Sîrbu ◽  
Paulina Anastasiu ◽  
Mihaela Urziceanu ◽  
Petronela Camen-Comănescu ◽  
Ioana-Minodora Sîrbu ◽  
...  
Keyword(s):  
European Union ◽  
Plant Species ◽  
Local Level ◽  
Alien Plants ◽  
Change Scenario ◽  
The European Union ◽  
Alien Plant Species ◽  
Myriophyllum Aquaticum ◽  
Alien Plant ◽  
The Impact

Abstract An assessement of the alien plants of Romania was conducted which considered the requirements of Regulation 1143/2014 of the European Union (EU). Thus, available data about the presence, invasiveness, distribution, pathways of introduction and their known impact in the territory of Romania were analysed. We found that of 36 plant species of EU concern, four are already established in Romania and widespread, at least locally or regionally: Ailanthus altissima, Asclepias syriaca, Elodea nuttallii and Impatiens glandulifera. For Humulus scandens there are some reports, but its presence and status require confirmation. Heracleum sosnowskyi and Ludwigia peploides are confirmed for only one location for each species. The presence of Cabomba caroliniana and Myriophyllum aquaticum in Romania is not confirmed. Most of the records are intentional introductions for ornamental purposes. Regarding their invasiveness, given the geographical origin and history of invasion in warmer climate regions (e.g., tropical, subtropical), many of the species listed as being of EU concern do not currently constitute a real threat to Romania, for the time being, but may do in a climate change scenario for the 2070s. Data about the impact of alien plant species and their management in Romania are scattered or completely missing. Coordinated institutional efforts are needed to increase the efficiency of the management of alien species at national and local level. These efforts should include: enhancing the legislation and the capacity of public institutions to manage invasive species, increasing the research interest in the science of this topic and promoting real measures to mitigate, control and remove alien plants.

The emerging invasive alien plants of the Drakensberg Alpine Centre, southern Africa

Bothalia ◽  
2012 ◽  
Vol 42 (2) ◽  
pp. 71-85 ◽  
Author(s):  
C. Carbutt
Keyword(s):  
Competitive Ability ◽  
Plant Invasions ◽  
Alien Plants ◽  
Suitable Habitat ◽  
Invasive Alien Plants ◽  
Alien Plant ◽  
Invasive Alien Plant ◽  
Management Interventions ◽  
Study Sites ◽  
Disturbed Habitats

An ‘early detection’-based desktop study has identified 23 taxa as ‘current’ emerging invasive alien plants in the Drakensberg Alpine Centre (DAC) and suggests a further 27 taxa as probable emerging invaders in the future. These 50 species are predicted to become problematic invasive plants in the DAC because they possess the necessary invasive attributes and have access to potentially suitable habitat that could result in them becoming major invaders. Most of the ‘current’ emerging invasive alien plant species of the DAC are of a northern-temperate affinity and belong to the families Fabaceae and Rosaceae (four taxa each), followed by Boraginaceae and Onagraceae (two taxa each). In terms of functional type (growth form), most taxa are shrubs (9), followed by herbs (8), tall trees (5), and a single climber. The need to undertake a fieldwork component is highlighted and a list of potential study sites to sample disturbed habitats is provided. A global change driver such as increased temperature is predicted to not only result in extirpation of native alpine species, but to also possibly render the environment more susceptible to alien plant invasions due to enhanced competitive ability and pre-adapted traits. A list of emerging invasive alien plants is essential to bring about swift management interventions to reduce the threat of such biological invasions.

scholarly journals No universal scale-dependent impacts of invasive species on native plant species richness

2014 ◽  
Vol 10 (1) ◽  
pp. 20130939 ◽  
Author(s):  
Thomas J. Stohlgren ◽  
Marcel Rejmánek
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Invasions ◽  
Plant Species Richness ◽  
Native Plant ◽  
Desert Ecosystems ◽  
Alien Plant ◽  
Native Plant Species ◽  
Wide Range ◽  
The Impact

A growing number of studies seeking generalizations about the impact of plant invasions compare heavily invaded sites to uninvaded sites. But does this approach warrant any generalizations? Using two large datasets from forests, grasslands and desert ecosystems across the conterminous United States, we show that (i) a continuum of invasion impacts exists in many biomes and (ii) many possible species–area relationships may emerge reflecting a wide range of patterns of co-occurrence of native and alien plant species. Our results contradict a smaller recent study by Powell et al. 2013 ( Science 339 , 316–318. ( doi:10.1126/science.1226817 )), who compared heavily invaded and uninvaded sites in three biomes and concluded that plant communities invaded by non-native plant species generally have lower local richness (intercepts of log species richness–log area regression lines) but steeper species accumulation with increasing area (slopes of the regression lines) than do uninvaded communities. We conclude that the impacts of plant invasions on plant species richness are not universal.

scholarly journals The first checklist of alien vascular plants of Kyrgyzstan, with new records and critical evaluation of earlier data. Contribution 1

2021 ◽  
Vol 9 ◽  
Author(s):  
Alexander Sennikov ◽  
Georgy Lazkov
Keyword(s):  
Central Asia ◽  
Plant Invasions ◽  
Second World War ◽  
Alien Plants ◽  
National Database ◽  
Herbarium Specimens ◽  
World War ◽  
Alien Plant ◽  
History Of ◽  
Second World

National checklists of alien plants and detailed databases of non-native plant occurrences are required to study and control regional and global plant invasions. No country in Central Asia has a national checklist of alien plants. A recent inventory counted 183 alien plant species in Kyrgyzstan, including archaeophytes and neophytes, established and casual. This preliminary checklist, which was developed for the Global Register of Introduced and Invasive Species in 2018, served as a starting point for the present study. A complete inventory of Xanthium in Kyrgyzstan has revealed that three alien species are resident in the country. Their correct nomenclature is X. orientale (syn. X. albinum, X. californicum, X. sibiricum auct.; invasive neophyle of the period of extensive grain import to the USSR after the Second World War), X. spinosum (invasive neophyte of the period of the Second World War, which arrived as a contaminant on the relocated livestock) and X. strumarium (syn. X. chinense, X. sibiricum; archaeophyte of the Neolithic period, introduced with wheat cultivation, which had lost its invasive status and appeared on the verge of extinction when its pool was no longer renewed by contaminated grain). A history of introduction to Central Asia is uncovered for all the species of Xanthium. A further spread is documented for Bunias orientalis, with a new record extending its distribution to the Eastern Tian-Shan; a complex history of its introduction to Europe and Central Asia is inferred from the archaeological data and its recent dispersal, and the pathways of its introduction to Kyrgyzstan are established. Erigeron annuus s.str. is reported as new to Kyrgyzstan and Uzbekistan, and E. lilacinus as new to Kyrgyzstan, Uzbekistan, Kazakhstan, Nepal and Tajikistan (it was previously recorded as E. annuus s.l. from the three latter countries, in which the presence of E. annuus s.str. is not confirmed). These closely related species differ in their pathways of introduction and invasion status: E. annuus s.str. is an invasive established alien which was imported as a contaminant of forage, whereas E. lilacinus is mostly a casual (locally persisting) alien introduced with contaminated seed of ornamental plants or nursery material, and also intentionally introduced and locally established in the Botanical Garden in Bishkek. Bidens tinctoria (syn. Coreopsis tinctoria) is newly recorded as a casual alien from a single locality in Kyrgyzstan; this species name is validly published here in conformity with the phylogeny of Coreopsideae. Point maps of species distributions in Kyrgyzstan are provided on the basis of a complete inventory of the literature data, herbarium specimens and documented observations, and our recent fieldwork. The maps are documented with a dataset of herbarium specimens and observations. Period and pathways of introduction, vectors of dispersal, current and historical invasion status, evidence of impact and distributional trend are established or inferred for each species. Each species is discussed in the context of plant invasions in Central Asia as a whole. These species accounts are part of the national database of alien plants which aims at producing a comprehensive overview and analysis of plant invasions in Kyrgyzstan.

scholarly journals Habitat type and community age as barriers to alien plant invasions in coastal species-habitat networks

2021 ◽  
Vol 133 ◽  
pp. 108450
Author(s):  
Francesco Lami ◽  
Stefano Vitti ◽  
Lorenzo Marini ◽  
Elisa Pellegrini ◽  
Valentino Casolo ◽  
...  
Keyword(s):  
Habitat Type ◽  
Plant Invasions ◽  
Alien Plant ◽  
Coastal Species ◽  
Habitat Networks

scholarly journals A fine-scale assessment of the ecosystem service-disservice dichotomy in the context of urban ecosystems affected by alien plant invasions

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Luke J. Potgieter ◽  
Mirijam Gaertner ◽  
Patrick J. O’Farrell ◽  
David M. Richardson
Keyword(s):  
Spatial Data ◽  
Cape Town ◽  
Plant Invasions ◽  
Alien Plants ◽  
Urban Landscapes ◽  
Alien Plant ◽  
Management Interventions ◽  
Trade Offs ◽  
Large Trees ◽  
Trees And Shrubs

Abstract Background Natural resources within and around urban landscapes are under increasing pressure from ongoing urbanisation, and management efforts aimed at ensuring the sustainable provision of ecosystem services (ES) are an important response. Given the limited resources available for assessing urban ES in many cities, practical approaches for integrating ES in decision-making process are needed. Methods We apply remote sensing techniques (integrating LiDAR data with high-resolution multispectral imagery) and combined these with supplementary spatial data to develop a replicable approach for assessing the role of urban vegetation (including invasive alien plants) in providing ES and ecosystem disservices (EDS). We identify areas denoting potential management trade-offs based on the spatial distribution of ES and EDS using a local-scale case study in the city of Cape Town, South Africa. Situated within a global biodiversity hotspot, Cape Town must contend with widespread invasions of alien plants (especially trees and shrubs) along with complex socio-political challenges. This represents a useful system to examine the challenges in managing ES and EDS in the context of urban plant invasions. Results Areas of high ES provision (for example carbon sequestration, shade and visual amenity) are characterized by the presence of large trees. However, many of these areas also result in numerous EDS due to invasions of alien trees and shrubs – particularly along rivers, in wetlands and along the urban edge where tall alien trees have established and spread into the natural vegetation (for example increased water consumption, increased fire risk and reduced soil quality). This suggests significant trade-offs regarding the management of species and the ES and EDS they provide. Conclusions The approach applied here can be used to provide recommendations and to guide city planners and managers to fine-tune management interventions at local scales to maximise the provision of ES.

scholarly journals Alien plant invasions in Mediterranean habitats: an assessment for Sicily

2021 ◽  
Author(s):  
Riccardo Guarino ◽  
Milan Chytrý ◽  
Fabio Attorre ◽  
Flavia Landucci ◽  
Corrado Marcenò
Keyword(s):  
Alien Species ◽  
Native Species ◽  
Vascular Plant ◽  
Regional Scale ◽  
Plant Invasions ◽  
Life Forms ◽  
Habitat Specificity ◽  
Alien Plant ◽  
Alien Flora ◽  
The Impact

AbstractLevels of plant invasions in different habitat types were assessed in several regional studies, but few of them were from the Mediterranean. Here we compare the levels of vascular plant invasion across habitats and plant communities of Sicily. We used a large dataset of plant species presences/absences in vegetation plots to analyze the invasion patterns across habitats considering biogeography, life form and phenology of alien plants. Vegetation plots were classified based on the EUNIS classification of European habitats. The invasiveness of each species was expressed in terms of its absolute and percentage frequency. Representation of different life forms and phenological patterns was compared between alien and native species. The fidelity of alien species to individual habitats was calculated using the phi coefficient. Our analysis shows that annual and woody species are the most represented life forms in the alien flora of Sicily and that alien species tend to have a longer flowering period than the native species. The investigated habitats differed strongly in their level of invasion by alien species, ranging from 0 to 15.6% of aliens of all species recorded. Most of the habitats were colonized by very few alien species or completely lacked them, except for sandy coasts, naturally-disturbed riverbeds, and synanthropic habitats. It must be noted, however, that the number of alien species occurring in a given habitat does not relate to the severity of the impact of invasion in that habitat. Some habitats are invaded by few (or single) species, which attain a high cover, transforming the whole ecosystem. The habitat-based approach proved to be suitable for evaluating the habitat specificity and frequency of alien species at a regional scale, improving the capacity for risk assessment in different ecological contexts.

scholarly journals Evaluating the environmental and social net-worth of controlling alien plant invasions in the Inkomati catchment, South Africa

Water SA ◽  
2020 ◽  
Vol 46 (1 January) ◽  
Author(s):  
Rashid Hassan ◽  
Siphokuhle Mahlathi
Keyword(s):  
South Africa ◽  
Plant Invasions ◽  
Social Benefit ◽  
Eradication Programme ◽  
Alien Plant ◽  
Net Worth ◽  
Invasive Alien Plant ◽  
Benefit Cost Analysis ◽  
The Social ◽  
The Impact

The present study attempted to bridge some gaps in the existing literature evaluating the net economic worth of South Africa’s Working for Water (WfW) programme for eradicating invasive alien plant species (IAPS). Specifically, the study employed the social benefit-cost analysis (BCA) methodology to assess the impact of accounting for the opportunity cost of invested capital funds and treating labour as a social benefit on the social worthiness of the WfW programme in the Inkomati catchment. The study also used improved measures of the value of other ecosystem services, particularly the carbon sequestration values. Results of the social BCA provided strong empirical evidence in support of the continuation of IAPS eradication activities, as economically and socially worthwhile investment of the country’s resources. The programme generates higher net worth under lower rates of discounting future values. This confirms the importance of the water-saving benefits, which continue theoretically for ever, at zero cost to the society, as all direct and indirect financial costs cease upon completion of the eradication operations. The social net worth of the IAPS eradication programme obviously increases when expenditure on labour wages was considered a social benefit rather than a direct financial cost, even under strict project funding scenarios that require funding through private capital markets, i.e., paying commercial rates of interest. However, more strategic planning for the control of IAPS is critically important given their high cost. Challenges facing the sustainability of IAPS eradication programmes in the study area and South Africa include: raising sufficient funding from private and public sources, and introducing incentive systems to encourage higher collaboration and participation of private landowners in the currently primarily publicly driven IAPS eradication efforts. The study also suggests a number of policy and technological reforms to address the said challenges.

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