Marr, Bruce R. Ellender, Darragh J. Woodford, Mhairi E. Alexander, Ryan J. In many countries around the world, the most damaging invasive plant species are grasses. However, the status of grass invasions in South Africa has not been documented recently. Vernon Visser, John R.
South Africa has committed to producing a National Status Report on Biological Invasions by October and thereafter every three years. This will be the first status report at a national level specifically on biological invasions. John R. Wilson, Mirijam Gaertner, David M. Richardson, Brian W. Optimising invasive fish management in the context of invasive species legislation in South Africa. South Africa hosts a large number of non-native freshwater fishes that were introduced for various industries. This study assesses the history and status of national legislation pertaining to invasive freshwater fishes, and the practical implications of the legislation for managing different species with contrasting distributions, impacts and utilisation value.
Darragh J. Woodford, Phillip Ivey, Martine S. Jordaan, Peter K. Kimberg, Tsungai Zengeya, Olaf L. This paper reviewed the benefits and negative impacts of alien species that are currently listed in the Alien and Invasive Species Regulations of the National Environmental. Management: Biodiversity Act Act no 10 of and certain alien species that are not yet listed in the regulations for which conflicts of interest complicate management. There is a long history of species being moved around the world by humans.
Assessing and managing the threat posed by Epipremnum aureum in South Africa. The predictive success of risk assessments is still largely a function of invasiveness elsewhere. Therefore, species that are invasive elsewhere should be prioritised for management, and where possible eradicated.
We set out to investigate the threat posed by the alien climber Epipremnum aureum Araceae and assess techniques for controlling the spread of the species in South Africa. Water hyacinth Eichhornia crassipes is considered the most damaging aquatic weed in the world. However, few studies have quantified the impact of this weed economically and ecologically, and even fewer studies have quantified the benefits of its control.
Fraser etal. Molecular identification of Azolla invasions in Africa: The Azolla specialist, Stenopelmus rufinasus proves to be an excellent taxonomist. Biological control of Azolla filiculoides in South Africa with the Azolla specialist Stenopelmus rufinasus has been highly successful. However, field surveys showed that the agent utilized another Azolla species, thought to be the native Azolla pinnata subsp. Madeira, M. Hill, F. Dray Jr. Coetzee, I. Paterson, P. Madeira etal. Unravelling the biogeographic origins of the Eurasian watermilfoil Myriophyllum spicatum invasion in North America.
Using phylogeographic analyses to determine the geographic origins of biological invaders is important for identifying environmental adaptations and genetic composition in their native range as well as biocontrol agents among indigenous herbivores. Michael L. Moody, Nayell Palomino, Philip S. Weyl, Julie A. Coetzee, Raymond M.
Newman, Nathan E. Harms, Xing Liu, and Ryan A. Moody etal. Muskett et al. Two in one: cryptic species discovered in biological control agent populations using molecular data and crossbreeding experiments. This study presents one of the few cases of cryptic species that has been confirmed to be reproductively isolated and therefore true species according to the biological species concept.
The cryptic species are of special interest because they were discovered within biological control agent populations. Iain D. Paterson, Rosie Mangan, Douglas A. Downie, Julie A. Coetzee, Martin P. Ashley M. Burke, Paul O. Downey, Thomas J. Compton 5.
Invasions everywhere | Nature Ecology & Evolution
The interaction between insect population density and culture age of fungus on the control of invasive weed water hyacinth. The possibilities of a positive or negative impact the biocontrol agents may have on each other as well as on the control of the weed itself, inspired these scientists to study the interactions between the mirid, Eccritotarsus catarinensis and the phytopathogen, Acremonium zonatum, biocontrol agents of water hyacinth Eichhornia crassipes. Naturally occurring phytopathogens enhance biological control of water hyacinth Eichhornia crassipes by Megamelus scutellaris Hemiptera: Delphacidae , even in eutrophic water.
Insect biological control agents directly damage target weeds by removal of plant biomass, but herbivorous insects have both direct and indirect impacts on their host plants and can also facilitate pathogen infection. Scientists compared the impact of fungicide surface-sterilised and unsterilised Megamelus scutellaris individuals and water hyacinth leaves on growth of the weed at two nutrient levels.
Sutton, S. Compton, J. Coetzee 7. Sutton etal. Have grass carp driven declines in macrophyte occurrence and diversity in the Vaal River, South Africa? Grass carp invasions worldwide have been shown to have severe impacts on macrophyte biodiversity and ecosystem functioning. This fish is an aggressive feeder on submerged macrophytes, as well as being an ecosystem engineer that can change water and sediment chemistry.
Was Myriophyllum spicatum L. Haloragaceae recently introduced to South Africa from Eurasia? The aim of this study was to determine if Myriophyllum spicatum was recently introduced from Eurasia by reconstructing the genetic relationships between South African and Eurasian M. Weyl etal. The invasive estuarine grass Spartina alterniflora was first detected in the Great Brak Estuary in Using herbicide treatment, this invasive grass has almost been eliminated from the estuary.
The aim of this study is to score impacts of all known alien amphibians, compare them to other taxonomic groups and determine the magnitude of their ecological and socio-economic impacts and how these scores relate to key traits. To apply the recently published EICAT protocol to an assessment of the magnitude of environmental impacts of alien bird species established worldwide. In order to effectively prevent biological invasions, the pathways of introduction need to be understood and managed. This paper looks at pathways of introduction using South Africa as a case study. Understanding and managing the introduction pathways of alien taxa: South Africa as a case study.
Biological Invasions Hoveka, van der Bank, Boatwright, Bezeng and Yessoufou. This paper discusses the role and importance of pollinators in seed germination of invasive plants in the family Proteaceae, as well as that of autonomous self-fertilisation. The importance of pollinators and autonomous self-fertilisation in the early stages of plant invasions: Banksia and Hakea Poteaceae as case studies. Among many introduction pathways of non-native species, horticulture is a particularly important driver of plant invasions. In recent decades, the horticultural industry expanded globally and changed structurally through the emergence of new distribution channels, including internet trade e-commerce.
Comparisons of isotopic niche widths of some invasive and indigenous fauna in a South African river. Biological invasions threaten ecosystem integrity and biodiversity, with numerous adverse implications for native flora and fauna. Established populations of two notorious freshwater invaders, the snail Tarebia granifera and the fish Pterygoplichthys disjunctivus , have been reported on three continents and are frequently predicted to be in direct competition with native species for dietary resources. Hill, J. Responses of adult Hydrellia lagarosiphon to a revised diet: implications for life cycle studies and laboratory culturing techniques.
Preservation of an insect culture under laboratory conditions is essential for its study. Numerous diets have been developed for entomophagous insects undergoing screening as biological control agents in attempts to improve the nutritional quality of food provided in laboratory settings. Mangan etal. Morphological variations in southern African populations of Myriophyllum spicatum: Phenotypic plasticity or local adaptation? Variability in aquatic plant morphology is usually driven by phenotypic plasticity and local adaptations to environmental conditions experienced.
This study aimed to elucidate which of these drivers is responsible for the morphological variation exhibited by three populations of Myriophyllum spicatum L.
Haloragaceae , a submerged aquatic plant whose status as native or exotic within southern Africa is uncertain. Weyl, J. Small naturalised populations of the broadleaf paperbark tree Melaleuca quinquenervia were been discovered in SA in Discovery of Melaleuca quinquenervia in South Africa Size: 3. A first official record of a naturalised population of Mimosa albida var. A total of 61 plants were recorded along 1. Efforts are underway to eradicate the population. The paper is a first formal report of the species outside of cultivation in Africa.
First official record of a naturalised population of Mimosa albida var. Size: 1. Using cacti in South Africa as a case study, the authors develop a framework for assisting decision-makers in developing effective non-native species policies. The rate of transportation, introduction, dissemination, and spread of non-native species is increasing despite growing global awareness of the extent and impact of biological invasions. Effective policies are needed to prevent an increase in the negative environmental and economic impacts caused by invasive species.
Legislative approaches for preventing invasions. Size: The horticultural industry is recognised as one of the major pathways for the introduction and spread of invasive alien plants IAPs around the world. The paper assesses the awareness and attitudes of Cape Town nursery managers in regard to invasive species regulations. Aliens in the nursery.
A new invasive cactus species Echinopsis oxygona is discovered in the Tugela River basin in KwaZulu-Natal, and new records of Opuntia microdasys are highlighted. Invasive status of newly recorded cactus species in the central Tugela River Basin Size: 2. This paper looks as biogeographical factors in the role of invasive species distribution in plants, from a South African perspective. Plant invasions as a biogeographic essay: Vegetation biomes constrain the distribution of invasive alien species assemblages.
South African Journal of Size: 1. Effect of nutrient quality and leaf age of water hyacinth, Eichhornia crassipes , on the development of its co-evolved herbivore, Eccritotarsus catarinensis Hemiptera: Miridae. Burke et al Size: Effect of water trophic level on the impact of the water hyacinth moth Niphograpta albiguttalis on Eichhornia crassipes. Eutrophication contributes to the proliferation of alien invasive weed species such as water hyacinth Eichhornia crassipes.
Although the South American moth Niphograpta albiguttalis was released in South Africa in as a biological control agent against water hyacinth, no post-release evaluations have yet been conducted here. Canavan etal. The herbivorous arthropods associated with the invasive alien plant, Arundo donax , and the native analogous plant, Phragmites australis , in the Free State Province, South Africa. Water hyacinth, Eichhornia crassipes Pontederiaceae , reduces benthic macroinvertebrate diversity in a protected subtropical lake in South Africa. The socio-economic impacts of the free-floating aquatic plant water hyacinth Eichhornia crassipes on aquatic systems are well documented, yet the impacts on aquatic biodiversity, particularly invertebrate biodiversity, are less well understood.
This study aimed to determine whether the presence of water hyacinth altered the diversity and assemblage structure of benthic macroinvertebrates in a conservation area. Coetzee etal. In fact, the rate at which new species formed declined to approximately zero during the Frasnian crisis interval. This result support those of genus-level analyses by McGhee and Bambach et al. Secondly, the primary mechanism for speciation reduction was the loss of speciation via vicariance Stigall b. Effectively, the primary mechanism of speciation in Earth history was shut down during the Late Devonian crisis interval.
The speciation loss can be attributed to the high levels of species invasions present at this time Stigall a , b. Successful modern invasive species commonly exhibit broad levels of ecological tolerance, which allows them to exploit many types of environments Davis This attribute also indicates that where invasive species are present, opportunities for new species to form would be reduced due to competition for resources.
Incipient species, as discussed above, have relatively small population sizes, which means that these populations are more likely to become extinct than thrive and expand their population sizes when faced with fierce competition for resources. To examine the biogeographic impact of the invasion, geographic ranges of articulate brachiopod species were reconstructed using GIS, as in the Devonian study by Stigall a ; Fig. Species distribution data were collected for 45 species across six depositional sequences C1 through C6 to incorporate the interval prior to and following the Richmondian Invasion, which occurred in the C4 sequence.
Each depositional sequence comprises strata deposited during a single cycle of rise and fall in relative sea level Patzkowsky and Holland Individual depositional sequences, therefore, can be used as proxies for temporal intervals. Brachiopod species preserved in Cincinnatian strata during this interval were categorized into four groups: 1 species native to the Cincinnati region that became extinct by the end of the Maysvillian, 2 natives species that persisted into the Richmondian, 3 extrabasinal invaders that arrived during the Richmondian invasion, and 4 species that evolved in the Richmondian from Cincinnatian natives.
The ecological niches of Cincinnatian brachiopods were modeled in a series of analyses Dudei and Stigall ; Malizia and Stigall ; Stigall ; Walls and Stigall that examined the relative amount of niche stability in species before, during, and after the Richmondian Invasion. Species niches were modeled using a technique called ecological niche modeling for three time slices in each interval, generating a total of nine time slices for comparison Fig. Analyses indicated that species conserved the parameters of their ecological niche to a high degree during the pre-invasion interval Malizia and Stigall ; Walls and Stigall Although no biotic invasion occurred during this interval, the Cincinnatian region and its biota did experience gradual environmental change due to gradual shallowing of the basin during the three time slices before the invasion Walls and Stigall The overall biotic response to gradual change was niche conservation.
Intervals of more rapid sea level rise exhibited slightly higher levels of niche evolution than during slower sea level change, but the overall pattern was still dominantly one of niche conservatism in the pre-invasion interval.
However, the degree of niche conservatism declined significantly during the invasion interval Dudei and Stigall ; Malizia and Stigall This indicates that the response of the biota to invasion pressure was to undergo adaptation and niche evolution. The interval of niche evolution continued throughout the invasion and at least the first million years of the post-invasion interval, as niche stability increased very slightly post-invasion but remained substantially below pre-invasion stability levels Malizia and Stigall Acknowledgments Thanks to Jonathan Hendricks and an anonymous reviewers for constructive reviews and to Bruce Lieberman for the invitation to submit this research to this edited volume.
Origination, extinction, and mass depletions of marine diversity. CrossRef Google Scholar. Blaustein RJ. The great reshuffling: human dimensions of invasive species. Google Scholar. Davis MA. Biotic globalization: does competition from introduced species threaten biodiversity? Invasion biology. Oxford: Oxford University Press; Decoupling the taxonomic and ecologic severity of Phanerozoic marine mass extinctions. Using ecological niche modeling to assess biogeographic and niche response of brachiopod species to the Richmondian Invasion Late Ordovician in the Cincinnati Arch.
Palaeogeogr Palaeoclimatol Palaeoecol. Enserink M. Biological invaders sweep in. The role of introduced species in the degradation of an island ecosystem: a case history of Guam. Annu Rev Ecol Syst.
Hutchinson GE. Concluding remarks. Devonian eustastic fluctuations in Euramerica. Geol Soc Am Bull. Extinction rates. Invasion ecology. Singapore: Blackwell; Sunderland, Massachusetts: Sinauer; Analyzing niche stability in Late Ordovician articulated brachiopods during the Richmondian Invasion. Geological Society of America Abstracts with Programs.
Niche stability in Late Ordovician articulated brachiopod species before, during, and after the Richmondian Invasion. Mayr E. Systematics and the origin of species. New York: Columbia Univ. Press; McGhee Jr GR. A sea without fish: life in the Ordovician sea of the Cincinnati region. Bloomington: Indiana University Press; Extinction, invasion, and sequence stratigraphy; patterns of faunal change in the Middle and Upper Ordovician of the Eastern United States. Boulder, Colorado: Geological Society of America; Update on the envrionmental and economic costs associated with alien-invasive species in the United States.
Ecol Econ. Using GIS to unlock the interactions between biogeography, environment, and evolution in Middle and Late Devonian brachiopods and bivalves. Palaeogeography, Palaeoclimatology, Palaeogeography. Stigall AL. Invasive species and biodiversity crises: testing the link in the Late Devonian.
PLoS One. Application of niche modeling to analyze biogeographic patterns in Palaeozoic brachiopods: evaluating niche stability in deep time. Memoirs of the Association of Australasian Palaeontologists. GSA Today. Using ecological niche modeling to evaluate niche stability in deep time. J Biogeogr. The potato was introduced to Europe in the s, and became a major food plant in Ireland and many other countries.
A strain of the blight fungus somehow reached western Europe in the mid- s, where, coupled with weather conditions favorable to its development, it decimated potato crops. In Ireland, the almost total loss of the potato crop led to famine, in which 1. Closely related strains of the fungus have since invaded all major potato-growing areas of the world. In the twentieth century, these strains have been more or less controlled by a combination of resistant potato varieties, fungicidal treatments, and sanitation. Prior to the s, strains of the blight fungus affecting potato and tomato Lycopersicon esculentum crops were of a single mating type, which reproduced asexually and showed little genetic variability.
This genetic uniformity contributed significantly to the success of disease control. In the early s, however, resurgence of late blight disease began to occur in the Old World, and by the late s and early s, severe outbreaks of the disease also affected potato crops in Canada and the United States Fry and Goodwin These outbreaks were traced to new strains of late blight fungus that apparently originated in Mexico.
The new strains were much more virulent and were resistant to one of the primary fungicides previously used to control late blight. These strains have already caused production losses measured in millions of dollars in parts of the Pacific Northwest. Even more serious is the evolutionary potential created by these new forms of the late blight fungus. The new strains belong to the complementary mating type of the earlier fungus, so their arrival now makes possible sexual reproduction and resulting genetic recombination.
Sexual reproduction has already been confirmed in several locations Goodwin et al. New fungal strains that appear to be the result of recombination between different mating types have also been found on tomatoes in North Carolina Wangsomboondee et al. Thus, the stage has been set for the rapid evolution of new genetic races of a fungus that is known to affect two of the world's most important crops, potatoes and tomatoes, both of which are members of a plant family containing a host of other cultivated plants.
Invasive alien species are now recognized throughout the world as one of the most serious ecological and economic threats of the new millennium Pimentel Alien plants are reducing the productivity of agricultural crops, pastures, and rangelands and are disrupting many natural terrestrial ecosystems. In addition, alien plants are choking waterways and altering the function of freshwater and marine ecosystems.
Many of these plants are now legally designated as noxious weeds. Alien animals are also altering the biotic structure of land, freshwater, and marine ecosystems and are pushing many native species toward extinction. Introduced disease agents are infecting crops, livestock, fish and game animals, timber trees, and horticultural plants.
Increasingly, introduced diseases and their vectors are posing new threats to human health as well. The worldwide total of species introduced to new geographical regions by human agency probably approaches half a million species Pimentel et al. The direct and indirect economic costs of these invaders are enormous.
Additional direct losses result from damage by aliens to fisheries, navigation, and industry. Still other costs are incurred in fighting alien species that are endangering native plants and animals. Invasions of natural ecosystems by alien species are degrading their unique aesthetic and recreational values.
Invasions of alien species are certain to continue, in spite of increasing awareness and prevention efforts. Much of this invasion is likely to occur as a result of increasing international trade and travel Ewel et al. For the period from to , for example, Levine and D'Antonio examined the relationship between value of foreign imports to the United States and the numbers of alien mollusks, plant pathogens, and insects becoming established.
The most conservative model predicted that between and some three species of mollusks, five species of plant pathogens, and species of alien insects are likely to become established in the United States. Less conservative models gave numerical predictions more than tenfold greater. Increased internal trade and traffic, including exchanges of organisms mediated via the Internet see, e. These threats, however, are only the tip of an ecological and evolutionary iceberg Palumbi