223 research outputs found

    Alien plant species list and distribution for Camdeboo National Park, Eastern Cape Province, South Africa

    Get PDF
    Protected areas globally are threatened by the potential negative impacts that invasive alien plants pose, and Camdeboo National Park (CNP), South Africa, is no exception. Alien plants have been recorded in the CNP since 1981, before it was proclaimed a national park by South African National Parks in 2005. This is the first publication of a list of alien plants in and around the CNP. Distribution maps of some of the first recorded alien plant species are also presented and discussed. To date, 39 species of alien plants have been recorded, of which 13 are invasive and one is a transformer weed. The majority of alien plant species in the park are herbaceous (39%) and succulent (24%) species. The most widespread alien plant species in the CNP are Atriplex inflata (= A. lindleyi subsp. inflata), Salsola tragus (= S. australis) and cacti species, especially Opuntia ficus-indica. Eradication and control measures that have been used for specific problematic alien plant species are described

    Factors influencing the distribution of Cactoblastis cactorum, a biological control agent of Opuntia stricta in Kruger National Park, South Africa

    Get PDF
    Cactoblastis cactorum, a phycitid moth, has been used with considerable success as a biological control agent against several different cactus species in many parts of the world, including Opuntia stricta in Kruger National Park [KNP], South Africa. Although the moth has become widespread and abundant in KNP, its populations have not reached levels where it is able to provide the desired level of control on the alien species which has invaded more than 35 000 ha of the park and continues to spread. Although several factors, especially acquired predators and parasitoids, are known to curb the abundance of C. cactorum in South Africa, the extent to which this applies in KNP is unknown. Logistic regression and Canonical Community Analysis were used to determine the biotic and abiotic factors affecting the distribution and abundance of C. cactorum in KNP. To do this, maps of the ranges of the insect and host plant were constructed and integrated with other environmental features. The logistic regression showed that O. stricta density had no influence on whether or not C. cactorum was present in an area. The Canonical Community Analysis suggested that a high fire frequency, the herbicide control programme and the presence of small host plants may be important in limiting the distribution of C. cactorum, either directly or indirectly, through impacts on associated predators or parasitoids

    Environmental factors influencing the distribution of Opuntia stricta, an invasive alien plant in the Kruger National Park, South Africa

    Get PDF
    Opuntia stricta (Cactaceae), an alien weed, has invaded an area of more than 35 000 ha in the Skukuza region of the Kruger National Park [KNP]. The distribution of the plant and features of the environment were used to identify biotic and abiotic factors which may be affecting the distribution and density of the plant. A Canonical Community Analysis revealed that none of the environmental factors that were monitored influenced the distribution or abundance of O. stricta in KNP. There were no apparent natural barriers that might limit the occurrence of O. stricta within the KNP. The study provides insight into the relationship between the invader and host environment, showing that there is a high probability that, unless there is appropriate intervention, O. stricta will eventually colonise the entire KNP

    Scenarios for the management of invasive Acacia species in a protected area : implications of clearing efficacy

    Get PDF
    CITATION: Cheney, C. et al. 2019. Scenarios for the management of invasive Acacia species in a protected area : implications of clearing efficacy. Journal of Environmental Management, 238:274-282. doi:10.1016/j.jenvman.2019.02.112The original publication is available at https://www.sciencedirect.com/journal/journal-of-environmental-managementIn many protected areas in South Africa, invasive Australian Acacia species pose on-going management challenges, perpetuating high long-term management costs. Due to limited availability of resources, conservation actions need to be prioritised within and across Protected Areas (PA). We draw on comprehensive datasets spanning over 20 years from the Table Mountain National Park to model long-term outcomes of clearing Acacia species at different levels of management clearing efficacy. We test a 50 year outlook based on current and 38 incremental levels of management efficacy, ranging from 5 to 100%, to assess under which scenarios a management goal of reducing Acacia density to below 1 plant per hectare for the 22,671 ha protected area is achieved. With the current clearing resources and maximum clearing efficacy (100% control), it would take between 32 and 42 years to attain the management goal. The modelling revealed two main drivers of Acacia persistence. Firstly, germination of seeds added to the seedbank from standing plants made a significantly larger contribution to future clearing requirements than fire stimulated seed germination or the existing (pre-management) seedbank. Secondly the relationship between the number of hectares and management units that could be treated and the efficacy of the treatment was non-linear. When clearing efficacy was decreased from 100% to the current project minimum target of 80% efficacy, the goal was not achieved in all areas, but the area that reached a density of<1 plant per hectare was significantly reduced to 53% of the PA for the simulated 50 years. Results emphasize the need to differentiate between increasing financial resources and increasing efficacy. While increasing financial resources allows for increased effort, this is of little value for Acacia management in the absence of an increase in clearing efficacy, as low quality implementation perpetuates the need for large budgets over time. Conversely, improving efficacy allows for decreased budget requirements over time, allowing fund redirection to additional areas of alien species management such as the early detection and rapid control of newly introduced species.https://www.sciencedirect.com/science/article/pii/S0301479719302725?via%3DihubPublisher’s versio

    Pragmatic trials of non-NHS interventions: experiences from a Randomised Controlled Trial of the Strengthening Families 10-14 UK Programme (SFP10-14 UK)

    Get PDF
    Background: Pragmatic trials of public health interventions outside the NHS are relatively scarce, much needed and face particular challenges. These include funding, of intervention costs in particular; trial implementation in professional and organisational cultures unused to randomised trial procedures, including randomisation, maintaining the counterfactual, recruitment; and relevance of findings for and translation into policy and practice. Objectives: The current NPRI funded trial of SFP 10-14 UK is presented as a case study to discuss these issues, solutions and remaining barriers. The SFP 10-14 UK programme aims to strengthen areas of family life that protect against substance misuse, for example, parenting, communication, and young people’s resilience skills. The SFP 10-14 UK is being delivered by statutory and voluntary agencies in six local authority areas across Wales, and is offered to mixed groups comprised of families from the general population, and families who may experience/present challenges within a group setting. Methods: The trial aims to recruit 748 families, 374 of whom will be randomised to receive the usual services available to families within their local area. 374 families will receive the SFP 10-14 UK in addition to usual care. Families are identified by staff employed within the statutory services and voluntary sectors and referred to embedded research staff for recruitment. Results: Challenges encountered related to a lack of awareness of the randomised trial as a research paradigm among staff and key referring agencies, related concerns about the ethics of randomisation and the maintenance of the counterfactual among the usual care group, and challenges regarding the maintenance of recruitment and intervention fidelity. Whilst a challenge in itself, partnership working with delivery agencies, programme trainers, and the Welsh Assembly Government at all stages of the development, funding and conduct of the trial has proved an important strategy to overcome these issues. Conclusions: This trial seeks to generate evidence on the effectiveness and cost effectiveness of the SFP10-14 UK which is of direct relevance to policy makers, commissioners and practitioners. The trial highlights that strategic partnership working, the winning of ‘hearts and minds’ regarding the ethics and operationalisation of randomisation, and maintaining the balance between internal and external validity are key areas of focus for the successful conduct of pragmatic trials in non-NHS settings. The lessons learnt from its implementation will be important for future multi-sector/agency policy trials and for role out of the intervention if found to be efficacious

    Predicting incursion of plant invaders into Kruger National Park, South Africa : the interplay of general drivers and species-specific factors

    Get PDF
    The original article is available at www.plosone.orgBackground: Overcoming boundaries is crucial for incursion of alien plant species and their successful naturalization and invasion within protected areas. Previous work showed that in Kruger National Park, South Africa, this process can be quantified and that factors determining the incursion of invasive species can be identified and predicted confidently. Here we explore the similarity between determinants of incursions identified by the general model based on a multispecies assemblage, and those identified by species-specific models. We analyzed the presence and absence of six invasive plant species in 1.061.5 km segments along the border of the park as a function of environmental characteristics from outside and inside the KNP boundary, using two data-mining techniques: classification trees and random forests. Principal Findings: The occurrence of Ageratum houstonianum, Chromolaena odorata, Xanthium strumarium, Argemone ochroleuca, Opuntia stricta and Lantana camara can be reliably predicted based on landscape characteristics identified by the general multispecies model, namely water runoff from surrounding watersheds and road density in a 10 km radius. The presence of main rivers and species-specific combinations of vegetation types are reliable predictors from inside the park. Conclusions: The predictors from the outside and inside of the park are complementary, and are approximately equally reliable for explaining the presence/absence of current invaders; those from the inside are, however, more reliable for predicting future invasions. Landscape characteristics determined as crucial predictors from outside the KNP serve as guidelines for management to enact proactive interventions to manipulate landscape features near the KNP to prevent further incursions. Predictors from the inside the KNP can be used reliably to identify high-risk areas to improve the costeffectiveness of management, to locate invasive plants and target them for eradication.Publisher's versio

    A feasibility trial to examine the social norms approach for the prevention and reduction of licit and illicit drug use in European University and college students.

    Get PDF
    Background: Incorrect perceptions of high rates of peer alcohol and tobacco use are predictive of increased personal use in student populations. Correcting misperceptions by providing feedback has been shown to be an effective intervention for reducing licit drug use. It is currently unknown if social norms interventions are effective in preventing and reducing illicit drug use in European students. The purpose of this paper is to describe the design of a multi-site cluster controlled trial of a web-based social norms intervention aimed at reducing licit and preventing illicit drug use in European university students. Methods/Design: An online questionnaire to assess rates of drug use will be developed and translated based on existing social norms surveys. Students from sixteen universities in seven participating European countries will be invited to complete the questionnaire. Both intervention and control sites will be chosen by convenience. In each country, the intervention site will be the university that the local principal investigator is affiliated with. We aim to recruit 1000 students per site (baseline assessment). All participants will complete the online questionnaire at baseline. Baseline data will be used to develop social norms messages that will be included in a web-based intervention. The intervention group will receive individualized social norms feedback. The website will remain online during the following 5 months. After five months, a second survey will be conducted and effects of the intervention on social norms and drug use will be measured in comparison to the control site. Discussion: This project is the first cross-national European collaboration to investigate the feasibility of a social norms intervention to reduce licit and prevent illicit drug use among European university students. Final trial registration number DRKS00004375 on the ‘German Clinical Trials Register’.This study is funded by the European Commission, Directorate General Justice, Freedom and Security (JLS/2009-2010/DPIP/AG

    Rapid, field-deployable method for collecting and preserving plant metabolome for biochemical and functional characterization

    Full text link
    Study of plant metabolome is a growing field of science that catalogs vast biochemical and functional diversity of phytochemicals. However, collecting and storing samples of plant metabolome, sharing these samples across the scientific community and making them compatible with bioactivity assays presents significant challenges to the advancement of metabolome research. We have developed a RApid Metabolome Extraction and Storage (RAMES) technology that allows efficient, highly compact, field-deployable collection and storage of libraries of plant metabolome. RAMES technology combines rapid extraction with immobilization of extracts on glass microfiber filter discs. Two grams of plant tissue extracted in ethanol, using a specially adapted Dremel® rotary tool, produces 25±35 replicas of 10 mm glass fiber discs impregnated with phytochemicals. These discs can be either eluted with solvents (such as 70% ethanol) to study the metabolomic profiles or used directly in a variety of functional assays. We have developed simple, non-sterile, anti-fungal, antibacterial, and anti-oxidant assays formatted for 24-multiwell plates directly compatible with RAMES discs placed inside the wells. Using these methods we confirmed activity in 30 out of 32 randomly selected anti-microbial medicinal plants and spices. Seven species scored the highest activity (total kill) in the anti-bacterial (bacteria from human saliva) and two antifungal screens (Fusarium spp. and Saccharomyces cerevisiae), providing functional validation of RAMES technology. RAMES libraries showed limited degradation of compounds after 12 months of storage at -20ÊC, while others remained stable. Fifty-eight percent of structures characterized in the extracts loaded onto RAMES discs could be eluted from the discs without significant losses. Miniaturized RAMES technology, as described and validated in this manuscript offers a labor, cost, and time-effective alternative to conventional collection of phytochemicals. RAMES technology enables creation of comprehensive metabolomic libraries from various ecosystems and geographical regions in a format compatible with further biochemical and functional studies
    • …
    corecore