Study of the impacts of biological invasions, a pervasive component of global change, has generated remarkable understanding of the mechanisms and consequences of the spread of introduced populations. The growing field of invasion science, poised at a crossroads where ecology, social sciences, resource management, and public perception meet, is increasingly exposed to critical scrutiny from several perspectives. Although the rate of biological invasions, elucidation of their consequences, and knowledge about mitigation are growing rapidly, the very need for invasion science is disputed. Here, we highlight recent progress in understanding invasion impacts and management, and discuss the challenges that the discipline faces in its science and interactions with society.

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Impacts of biological invasions: what's what and the way forward

Much as Rachel Carson's \"Silent Spring\" was a call to action against the pesticides that were devastating bird populations, Charles S. Elton's classic \"The Ecology of Invasions by Animals and Plants\" sounded an early warning about an environmental catastrophe that has become all too familiar today-the invasion of nonnative species. From kudzu to zebra mussels to Asian long-horned beetles, nonnative species are colonizing new habitats around the world at an alarming rate thanks to accidental and intentional human intervention. One of the leading causes of extinctions of native animals and plants, invasive species also wreak severe economic havoc, causing $79 billion worth of damage in the United States alone. Elton explains the devastating effects that invasive species can have on local ecosystems in clear, concise language and with numerous examples. The first book on invasion biology, and still the most cited, Elton's masterpiece provides an accessible, engaging introduction to one of the most important environmental crises of our time. Charles S. Elton was one of the founders of ecology, who also established and led Oxford University's Bureau of Animal Population. His work has influenced generations of ecologists and zoologists, and his publications remain central to the literature in modern biology. \"History has caught up with Charles Elton's foresight, and \"The Ecology of Invasions\" can now be seen as one of the central scientific books of our century.\"-David Quammen, from the Foreword to \"Killer Algae: The True Tale of a Biological Invasion\

The Ecology of Invasions by Animals and Plants

The Vegetation of South Africa, Lesotho and Swaziland

OBJECTIVE To establish an indirect immunofluorescent test so as to improve the sensitivity and specificity of examination of antibodies to beta(2)-glycoprotein METHODS Full-length beta(2)GP cDNA was obtained from human hepatocellular cancer cell line HepG2 by RT-PCR and cloned into the mammalian expression vector pEGFP-C1 The recombinant plasmid pEGFP-beta(2)GP was transfected into HEp-2 cells RT-PCR, immunoblotting (IBT), confocal fluorescence microscopy, and indirect immunofluorescent test (IIF) were used to confirm the expression, localization, and antigenicity of fusion protein of green fluorescent protein (GFP) Serum specimens from 19 patients suspected as with secondary antiphospholipid syndrome (APS), 1 patient diagnosed as with primary APS, and 10 normal persons were detected with IIF-IgG-beta(2)GP1, ELISA-IgG-ACL, and ELISA-IgG-beta(2)GP I simultaneously RESULTS (1) The HEp-beta(2)GP I cells thus obtained retained their ability of expression of beta(2)GP-I-GFP for more than ten generations This beta(2)GP-I-GFP showed the antigenicity of beta(2)GP-I with a characteristic feature (2) Seven of the 20 serum specimens from APS patients showed characteristic immunofluorescent pattern No serum specimen from normal persons showed immunofluorescent staining The comparison of results of the three methods showed that the concordance between IIF-IgG-beta(2)GP I and ELISA-IgG-beta(2)GP I was the most perfect (Kappa = 0886) (3) HEp-beta(2)GP I retained the immunofluorescent property of HEp-2 cell CONCLUSION As a new kind of substrate of IIF, beta(2)GP I transfectant can be used to detect anti-beta(2)GP-I antibodies Transfeted HEp-2 cells keep the immunofluorescent property of HEp-2 cells in IFANA test and can be used as substrate for routine IFANA detection

[Expression of fusion proteins in beta(2)GP I gene-transfected HEp-2 cells and its clinical application].

Summary 1 Global change and emerging concepts in ecology and evolution are leading to a growing interest in phenotypic plasticity (PP), the environmentally contingent trait expression observed in a given genotype. The need to quantify PP in a simple manner in comparative ecological studies has resulted in the prevalence of various indices instead of the classic approaches, i.e. a comparison of slopes in the norms of reactions (trait vs. environment plots). 2 The objectives of this study were: (i) to review the most common methods for quantitative estimation of PP; (ii) to apply them to a specific case study of growth and shoot‐root allocation responses to irradiance in seedlings of four woody species grown at 1%, 6%, 20% and 100% full sunlight; and (iii) to propose new methods of estimating PP. 3 The 17 different plasticity indices analysed rendered disparate results, with cross-overs in species PP rankings. Statistical comparisons of PP among species were not possible with most of the indices due to the lack of confidence intervals. The non-linear responses of the traits made the use of the slope of the reaction norm to quantify PP unrealistic, and raised awareness on values derived from studies that consider just two environments. 4 We propose an alternative approach to quantify PP based on phenotypic distances among individuals of a given species exposed to different environments, which is summarized in a relative distance plasticity index (RDPI) that allows for statistical comparisons of PP between species (or populations within species). RDPI was significantly correlated with 12 out of the 17 PP indices analysed. An index including the environmental range leading to the different phenotypes (environmentally standardized plasticity index, ESPI), and thus expressing plasticity per unit of environmental change, is also proposed. 5 The new indexes can statistically segregate and unambiguously rank species according to their PP, which can foster a better understanding of plant ecology and evolution, particularly when common protocols are used by different investigators.

https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2745.2006.01176.x

Quantitative estimation of phenotypic plasticity : bridging the gap between the evolutionary concept and its ecological applications

We review the key features of Lantana (Lantana camara L.), an invasive plant species considered to be among the world's 10 worst weeds. Lantana occurs in diverse habitats and on a variety of soil types, and its spread is encouraged by animal activities and by human disturbances, such as cultivation, road construction, and changes in fire regimes. Lantana is morphologically distinct in the different regions of its invasive range compared to those regions in its native range. The biological attributes contributing to the success of Lantana as an invader species include: fitness homeostasis, phenotypic plasticity, dispersal benefits from destructive foraging activities, widespread geographic range, vegetative reproduction, fire tolerance, better competitive ability compared to native flora, and allelopathy. Mechanical, chemical and biological options for the eradication and control of Lantana are available. It is emphasized that ecosystem-level consequences of Lantana invasion, particularly on the biodiversity of native flora, are little understood and studies are needed to fulfill this knowledge gap.

http://www.tsusinvasives.org/dotAsset/15673596-901a-4685-b2be-04060394259b.pdf

Lantana invasion: An overview

Invasive species are a growing problem for the world, both ecologically and economically. The impact of invasive species on native species and ecosystems has been immense. Invasion is considered to be an important driver of global change. The impact on economy by these species is evident. The cost of impact which invasive species cause is now estimated to range from millions to billions of dollars and eventually it would be severe for all ecosystems. The various aspects of invasion related to ecology and economy have been summarized to give an insight into the problem and presumed solutions to invasion. Prediction of invasiveness is intricate, but economic and ecological outcome, either good or bad of species invasion, will soon pervade all countries and societies.

Plant invasions : Emerging trends and future implications

Invasion biology is a growing discipline with clear ecological, social and economic implications. A wide range of research effort is thus required to address the invasion problem, and literature on the topic is extensive. However, the extent to which the invasion biology research is addressing the challenges associated with management and mitigation of the impacts of invasions has been questioned. Using bibliometric analysis, we investigated the extent to which the literature on the subject contributes to implementation of knowledge generated, by addressing aspects of management, policy, and/or implementation; the impact of these papers as indicated by the number of citations they attract; and the geopolitical scale of focus of invasion ecology papers, particularly those that attempt to bridge the knowing-doing gap. We then compared these findings with the information needs of conservation practitioners. We first looked globally at popular search engines and then narrowed our focus to South Africa—one of three regions outside USA where researchers producing highly cited papers in invasion ecology are well represented. At this level, we conducted a content analysis of invasion ecology-related papers, of which at least one author was affiliated to a South African institution. The knowledge base in the field of invasion biology is comprised largely of research oriented towards “knowing”, while research aimed at strategically applying or implementing that knowledge is poorly represented in the scientific literature, and the scale of its emphasis is not local. Conservation practitioners clearly indicate a need for basic knowledge. However, invasion science must develop channels for effective engagement to ensure that the research is contextualised, and will deal with the complex ecological, social and economic challenges posed by invasions.

How wide is the "knowing-doing" gap in invasion biology?

Lantana camara, a native plant from tropical America, is considered one of the most harmful invasive species worldwide. Several studies have identified potentially invasible areas under scenarios of global change, on the assumption that niche is conserved during the invasion process. Recent studies, however, suggest that many invasive plants do not conserve their niches. Using Principal Components Analyses (PCA), we tested the hypothesis of niche conservatism for L. camara by comparing its native niche in South America with its expressed niche in Africa, Australia and India. Using MaxEnt, the estimated niche for the native region was projected onto each invaded region to generate potential distributions there. Our results demonstrate that while L. camara occupied subsets of its original native niche in Africa and Australia, in India its niche shifted significantly. There, 34% of the occurrences were detected in warmer habitats nonexistent in its native range. The estimated niche for India was also projected onto Africa and Australia to identify other vulnerable areas predicted from the observed niche shift detected in India. As a result, new potentially invasible areas were identified in central Africa and southern Australia. Our findings do not support the hypothesis of niche conservatism for the invasion of L. camara. The mechanisms that allow this species to expand its niche need to be investigated in order to improve our capacity to predict long-term geographic changes in the face of global climatic changes.

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Gyan P. Sharma

Papers

Lantana invasion: An overview

Plant invasions : Emerging trends and future implications

How wide is the "knowing-doing" gap in invasion biology?

Global invasion of Lantana camara: has the climatic niche been conserved across continents?

Lantana invasion alters soil nitrogen pools and processes in the tropical dry deciduous forest of India