Plant Invasions In Protected Areas Research Articles

Current and future plant invasions in protected areas: Does clonality matter?

AbstractAimProtected areas (PAs) play an important role in biodiversity conservation, but remain increasingly threatened by invasive alien plant species (IAPS) in conjunction with global climate change. The latter is modifying the distribution of the former, and the magnitude and direction of distributional changes are predicted to vary depending on species dispersal mode. Here, we address the question of whether clonality is expected to affect the future invasion pattern in PAs.LocationWorldwide.Time period1950–2100.Major taxa studied36 invasive alien plant species.MethodsWe used ensembles of three species distribution models (GLM, GAM and Maxent) based on >70,000 occurrence records to project the distribution of 36 of the world's most invasive clonal and non‐clonal plants in >20,000 PAs. Projections were based on three greenhouse gas concentration scenarios (low, medium and high) for 2080.ResultsClimate change showed little impact on the global invasion pattern in PAs, and clonality showed little effect when all biomes were processed in concert. However, we discerned that the future invasion risk of clonal IAPS markedly increased in biomes located at high elevation and high latitude compared with non‐clonal IAPS, while the risk decreased in lower‐elevation tropical and subtropical biomes where asexual reproduction may be a less successful trait. We also showed that invasion hot spots overlapped with biodiversity hot spots and two realms (i.e. Nearctic and Palearctic), which calls for bridging the gap between invasion and conservation sciences and for more concerted management strategies.Main conclusionsWe suggest that effective management of IAPS in PAs should consider in which biomes PAs are located as well as the reproductive traits of IAPS that are present or may become so.

Potential Risks of Plant Invasions in Protected Areas of Sri Lanka under Climate Change with Special Reference to Threatened Vertebrates

There is substantial global concern over the potential impacts of plant invasions on native biodiversity in protected areas (PAs). Protected areas in tropical island countries that host rich biodiversity face an imminent risk from the potential spread of invasive alien plant species. Thus, the aim of this study was to gain a general understanding of the potential risks of multiple plant invasions in PAs located in the tropical island of Sri Lanka under projected climate change. We conducted a further analysis of a multi-species climate suitability assessment, based on a previous study using the Maximum Entropy (MaxEnt) modeling approach, and tested how species invasion may change in protected areas under climate change. We evaluated how the climate suitability of 14 nationally recognized invasive alien plant species (IAPS) will vary within PAs and outside PAs by 2050 under two climate change scenarios, representative concentration pathways (RCP) 4.5 and 8.5. Our findings suggest that there will be increased risks from multiple IAPS inside PAs and outside PAs in Sri Lanka in the future; however, the potential risk is comparatively less in PAs. We provide an overview of the species richness of selected threatened vertebrate groups, which can be potentially impacted by IAPS in PAs. The findings of this study highlight important implications for the strategic management of plant invasions in PAs in order to safeguard native biodiversity, with special reference to vertebrates.

Identifying potential distributions of 10 invasive alien trees: implications for conservation management of protected areas.

Tree invasion has the potential to negatively affect biodiversity and ecosystems, with invasive alien trees (IATs) expanding widely in protected areas (PAs) across different habitats. Thus, the effectiveness of PAs might be reduced. Investigation of the distributions of IAT is urgently required to improve the effective conservation management of PAs. We projected the potential distributions of 10 IATs, which included Acacia mearnsii, Ardisia elliptica, Cecropia peltata, Cinchona pubescens, Leucaena leucocephala, Melaleuca quinquenervia, Miconia calvescens, Morella faya, Prosopis glandulosa, and Spathodea campanulata, that have a serious influence on global biodiversity and assessed the distribution possibilities of these IATs in PAs based on the PA categories of the International Union for Conservation of Nature (IUCN). The overall potential distributions of these 10 IATs included Latin America, central and southern Africa, southeastern Asia, eastern Australia and New Zealand, and western Europe. Annual mean temperature, temperature seasonality, annual precipitation, and soil bulk density were found to be important environmental variables for the potential distributions of these IATs. Overall, A. mearnsii, A. elliptica, C. peltata, L. leucocephala, M. quinquenervia, M. calvescens, and S. campanulata were distributed mainly in the IUCN PA categories of national parks and PAs with sustainable use of natural resources. We proposed the following for conservation management of PAs: (1) completion of species inventories for PAs, (2) better understanding of factors driving invasions in PAs, (3) assessment of the efficiency of management within particular PAs, and (4) evaluation of changes in trends regarding plant invasions in PAs under climate change conditions.

Plant invasion science in protected areas: progress and priorities

Invasive alien species are a major problem for managers of protected areas (PAs) worldwide. Until the 1980s biological invasions were widely considered to be largely confined to anthropogenically disturbed sites and the widespread disruption of ecosystems in PAs by invasive species was not globally perceived as a major threat. A working group of the SCOPE program on biological invasions in the 1980s showed that PAs are not spared from major disruptive effects of invasions. Early research focused on descriptive studies of the extent to which PAs were invaded. More recent research explored drivers of invasion, and in the last decade much work has focused on understanding the impacts of invasions. We review the current understanding of alien plant invasions in PAs, focusing on four themes: (1) the status and macroecological patterns of alien plant invasions; (2) the threats that invasive alien plants (IAPs) pose and the impacts detected to date; (3) the current focus of invasion science in PAs; and (4) research priorities for advancing science-based management and policy. Of a sample of 59 widespread IAP species from a representative sample of 135 PAs globally, trees make up the largest proportion (32%), followed by perennial herbs (17%) and shrubs (15%). About 1857 papers have been published on alien species in PAs; 45% have focused on alien plants. Some textbook examples of impacts by IAPs originate from PAs, illustrating the severe threat to the core function of PAs. Impacts have been quantified at the species and community levels through the displacement and alteration of habitats. In some cases, native species abundance, diversity and estimated species richness have been altered, but reversed following control. At an ecosystem level, invasive plants have radically altered fire regimes in several PAs, in some cases causing regime shifts and transforming woodlands or savannas to grasslands. Invasions have also had a major impact on nutrient cycles. Protected areas are performing an increasingly important part of the global response to stem the rate of environmental change. Despite this, integrated efforts involving science, management and policy that are sufficiently resourced to generate insights on the status and dynamics of IAPs in PAs are insufficient or even lacking. Such efforts are needed to pave the way for monitoring trends, revising legislation and policies, and improving management interventions to reduce the extent and magnitude of impacts of invasive plants in PAs. While policy instruments to support management of non-native species date back to the 1930s, there has been a substantial increase in legislative support and general awareness since the early 2000s. Still, opportunities to improve research for PAs need to be created. Towards this goal, the establishment of a global PA research network could provide a unique vehicle to explore questions across species or functional groups and systems, at a scale currently beyond existing abilities. Developing an integrated global database with standardized, quantitative information could form part of such a networks function.

Plant invasions in protected areas: patterns, problems and challenges

This book is the first comprehensive global review of all aspects of alien plant invasions in protected areas. It provides insights into advances in invasion ecology emanating from work in protected areas, and the link to locally relevant management support for protected areas. The book provides in-depth case studies, illuminating interesting and insightful knowledge that can be shared across the global protected area network. The book includes the collective understanding of 80 ecologists and managers to extract as much information as possible that will support the long-term management of protected areas, and the biodiversity and associated ecosystem services they maintain.