CIB Associates
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- ItemApplying the Convention on Biological Diversity Pathway Classification to alien species in Europe(2020) Pergl, J.; Brundu, G.; Harrower, C.A.; Cardoso, A.C.; Genovesi, P.; Katsanevakis, S.; Lozano, V.; Perglova, I.; Rabitsch, W.; Richards, G.; Roques, A.; Rorke, S.L.; Scalera, R.; Schonrogge, K.; Stewart, A.; Tricarico, E.; Tsiamis, K.; Vannini, A.; Vil, M.; Zenetos, A.; Roy, H.E.The number of alien species arriving within new regions has increased at unprecedented rates. Managing the pathways through which alien species arrive and spread is important to reduce the threat of biological invasions. Harmonising information on pathways across individual sectors and user groups is therefore critical to underpin policy and action. The European Alien Species Information Network (EASIN) has been developed to easily facilitate open access to data of alien species in Europe. The Convention on Biological Diversity (CBD) Pathway Classification framework has become a global standard for the classification of pathways. We followed a structured approach to assign pathway information within EASIN for a subset of alien species in Europe, which covered 4169 species, spanning taxonomic groups and environments. We document constraints and challenges associated with implementing the CBD Pathway Classification framework and propose potential amendments to increase clarity. This study is unique in the scope of taxonomic coverage and also in the inclusion of primary (independent introductions to Europe) and secondary (means of dispersal for species expansion within Europe, after their initial introduction) modes of introduction. In addition, we summarise the patterns of introduction pathways within this subset of alien species within the context of Europe. Based on the analyses, we confirm that the CBD Pathway Classification framework offers a robust, hierarchical system suitable for the classification of alien species introduction and spread across a wide range of taxonomic groups and environments. However, simple modifications could improve interpretation of the pathway categories ensuring consistent application across databases and information systems at local, national, regional, continental and global scales. Improving consistency would also help in the development of pathway action plans, as required by EU legislation.
- ItemAn assessment of the Seychelles scale Icerya seychellarum (Westwood) as a potential insect of economic importance in South Africa(Entomolocigal Society of Southern Africa, 2019) Giliomee, J.H.; Millar, I.M.
- ItemComplex responses of global insect pests to climate warming(2020) Lehmann, P.; Ammunet, T.; Barton, M.; Battisti, A.; Eigenbrode, S.D.; Jepsen, J.U.; Kalinkat, G.; Neuvonen, S.; Niemela, P.; Terblanche, J.S.; Okland, B.; Bjorkman, C.Although it is well known that insects are sensitive to temperature, how they will be affected by ongoing global warming remains uncertain because these responses are multifaceted and ecologically complex. We reviewed the effects of climate warming on 31 globally important phytophagous (plant-eating) insect pests to determine whether general trends in their responses to warming were detectable. We included four response categories (range expansion, life history, population dynamics, and trophic interactions) in this assessment. For the majority of these species, we identified at least one response to warming that affects the severity of the threat they pose as pests. Among these insect species, 41% showed responses expected to lead to increased pest damage, whereas only 4% exhibited responses consistent with reduced effects; notably, most of these species (55%) demonstrated mixed responses. This means that the severity of a given insect pest may both increase and decrease with ongoing climate warming. Overall, our analysis indicated that anticipating the effects of climate warming on phytophagous insect pests is far from straightforward. Rather, efforts to mitigate the undesirable effects of warming on insect pests must include a better understanding of how individual species will respond, and the complex ecological mechanisms underlying their responses.
- ItemData descriptor: Pacific introduced flora (PaciFLora)(2021) Wohlwend, M.R.; Craven, D.; Weigelt, P.; Seebens, H.; Winter, M.; Kreft, H.; Dawson, W.; Essl, F.; van Kleunen, M.; Pergl, J.; Pyšek, P.; Space, J.; Thomas, P.; Knight, T.The Pacific region has the highest density of naturalized plant species worldwide, which makes it an important area for research on the ecology, evolution and biogeography of biological invasions. While different data sources on naturalized plant species exist for the Pacific, there is no taxonomically and spatially harmonized database available for different subsets of species and islands. A comprehensive, accessible database containing the distribution of naturalized vascular plant species in the Pacific will enable new basic and applied research for researchers and will be an important information source for practitioners working in the region.Here, we present PacIFlora, an updated and taxonomically standardized list of naturalized species, their unified nativeness, cultivation and invasiveness status, and their distribution across the Pacific Ocean, including harmonized location denommination. This list is based on the two largest databases on naturalized plants for the region, specifically the Pacific Island Ecosystems at Risk (PIER) and the Global Naturalized Alien Flora (GloNAF) databases. We provide an outlook for how this database can contribute to numerous research questions and conservation efforts.
- ItemDrivers of the relative richness of naturalized and invasive plant species on Earth(2019) Essl, F.; Dawson, W; Kreft, H.; Pergl, J.; Pyšek, P.; Van Kleunen, M.; Weigelt, P.; Mang, T.; Dullinger, S.; Lenzner, B.; Moser, D.; Maurel, N.; Seebens, H.; Stein, A.; Weber, E.; Chatelain, C.; Inderjit; Genovesi, P.; Kartesz, J.; Morozova, O.; Nishino, M.; Nowak, P.; Pagad, S.; Shu, W.-S.; Winter, M.Biological invasions are a defining feature of the Anthropocene, but the factors that determine the spatially uneven distribution of alien plant species are still poorly understood. Here, we present the first global analysis of the effects of biogeographic factors, the physical environment and socio-economy on the richness of naturalized and invasive alien plants. We used generalized linear mixed-effects models and variation partitioning to disentangle the relative importance of individual factors, and, more broadly, of biogeography, physical environment and socio-economy. As measures of the magnitude of permanent anthropogenic additions to the regional species pool and of species with negative environmental impacts, we calculated the relative richness of naturalized (= RRN) and invasive (= RRI) alien plant species numbers adjusted for the number of native species in 838 terrestrial regions. Socio-economic factors (per-capita gross domestic product (GDP), population density, proportion of agricultural land) were more important in explaining RRI (~50 % of the explained variation) than RRN (~40 %). Warm-temperate and (sub)tropical regions have higher RRN than tropical or cooler regions. We found that socio-economic pressures are more relevant for invasive than for naturalized species richness. The expectation that the southern hemisphere is more invaded than the northern hemisphere was confirmed only for RRN on islands, but not for mainland regions nor for RRI. On average, islands have ~6-fold RRN, and >3-fold RRI compared to mainland regions. Eighty-two islands (=26 % of all islands) harbour more naturalized alien than native plants. Our findings challenge the widely held expectation that socio-economic pressures are more relevant for plant naturalization than for invasive plants. To meet international biodiversity targets and halt the detrimental consequences of plant invasions, it is essential to disrupt the connection between socio-economic development and plant invasions by improving pathway management, early detection and rapid response.
- ItemThe effect of accessibility and value addition on the costs of controlling invasive alien plants in South Africa: A three-species system dynamics model in the fynbos and grassland biomes(2020) Crookes, D.J.; Blignaut, J.N.; Le Maitre, D.C.We developed a two-biome (grasslands and fynbos) system dynamics model simulating invasions of three invasive alien plant species - black wattle (Acacia mearnsii) and two pine species (Pinus patula and Pinus pinaster) - and some of the consequences. The model considers three components: invasion dynamics; revenue from the sale of woody products derived from clearing invasive alien plants; and a coefficient that models the effect of increased accessibility to invaded areas. The model shows that increasing the returns on value added products (VAPs) from invasive alien plants (IAPs) by between 70% and 130% results in positive nett present values (NPVs) of R2.7 million for P. patula, R151.7 million for P. pinaster and R115.9 million for A. mearnsii (1996 base year). At the same time, the invasion of these species is reduced dramatically by 2025. The results show that there is much scope, and indeed a clear requirement, for improved returns on investment from harvesting these species through increasing the returns from VAPs. However, accessibility to invaded areas would need to be increased for positive nett gains in water yields and other returns to be maximised.
- ItemThe effect of cross-boundary management on the trajectory to commonness in biological invasions(2020) Latombe, G.; Essl, F.; McGeoch, M.A.The number of alien species introduced and undergoing range expansion in novel environments is steadily increasing, with important consequences for native ecosystems. The efficacy of management planning and decision making to limit such invasions can be improved by understanding how interventions will impact the population dynamics of recently introduced species. To do so, here we expand on a typological framework that enables the classification of populations over time into 10 categories of commonness, and apply it to a spatially discrete metapopulation with heterogeneous abundance across spatial units (patches). We use this framework to assess the effect of cross-boundary management on the capacity of a metapopulation with different demographic and dispersal characteristics, including time lags in population growth, to become common. We demonstrate this framework by simulating a simple theoretical metapopulation model capable of exploring a range of environments, species characteristics, and management actions. Management can vary in the efficacy of propagule interception between patches, and in the synchronisation of the implementation of these measures across patches (i.e. if management is implemented simultaneously across patches). Simulations show that poor interception efficacy that only modestly reduces the number of propagules entering a given spatial unit cannot be compensated for by strong management synchronisation between spatial units. Management synchronisation will nonetheless result in a reduction in rates of spread once a critical threshold of interception efficacy has been met. Finally, time lags in population growth that may result in delayed spread are an important aspect to be considered in management as they can amplify the efficacy of management. Our results demonstrate how a typological framework of categories of commonness can be used to provide practical insights for the management of biological invasions.
- ItemImpacts of alien plant invasions on water resources and yields from the Western Cape Water Supply System (WCWSS)(2019) Le Maitre, D.; Gorgens, A.; Howard, G.; Walker, N.A key motivation for managing invasive alien plant (IAP) species is their impacts on streamflows, which, tor the wetter half of South Africa, are about 970 m(3).ha(-1).a(-1) or 1 444 mill.m(3).a(-1) (2.9% of naturalised mean annual runoff), comparable to forest plantations. However, the implications of these reductions for the reliability of yields from large water supply systems are less well known. The impacts on yields from the WCWSS were modelled under three invasion scenarios: 'Baseline' invasions; increased invasions by 2045 under 'No management; and under 'Effective control' (i.e. minimal invasions). Monthly streamflow reductions (SFRs) by invasions were simulated using the Pitman rainfall-runoff catchment model, with taxonspeci tic mean annual and low-flow SFR factors for dryland (upland) invasions and crop factors for riparian invasions. These streamflow reduction sequences were input into the WCWSS yield model and the model was run in stochastic mode for the three scenarios. The 98% assured total system yields were predicted to be +/- 580 million m(3).a(-1) under 'Effective control', compared with +/- 542 million niLa under 'Baseline' invasions and +/- 450 mill. m(3).a(-1) in 45 years' time with 'No management'. The 'Baseline' invasions already reduce the yield by 38 mill.m(3).a(-1) (two thirds of the capacity of the Wemmershoek Dam) and, in 45 years' time with no clearing, the reductions would increase to 130 mill. m(3).a(-1) (capacity of the Berg River Dam). Therefore I A P-related SFRs can have significant impacts on the yields of large, complex water supply systems. A key reason for this substantial impact on yields is that all the catchments in the WCWSS are invaded, and the invasions are increasing. Invasions also will cost more to clear in the future. So, the best option for all the water-users in the WCWSS is a combined effort to clear the catchments and protect their least expensive source of water.
- ItemInvasive Mesquite (Prosopis juliflora), an allergy and health challenge(2020) Hussain, M.I.; Shackleton, R.T.; El-Keblawy, A.; Perez, M.D.T.; Gonzalez, L.Mesquite (Prosopis juliflora (Sw.) DC), is an medium-sized tree (family Fabaceae, subfamily Mimosoideae), that has been intorcuded around the world. It is a noxious invasive species in Africa, Asia, and the Arabian Peninsula and a source of highly allergenic pollen in. The present article reviews the adverse allergenic effects of P. juliflora pollen on human and animal health. Several studies have diagnosed that allergenic pollens from Prosopis spp. can provoke respiratory problems. Prosopis pollen extracts have 16 allergenic components of which nine proteins were recognized as major allergens with some of them showing cross-reactivity. Clinically, understanding Prosopis pollen production, flowering seasonality, pollen load, and dispersal in the atmosphere are important to avoid allergic consequences for local inhabitants. Climate change and other pollution can also help to further facilitate allergenic issues. Furthermore, we document other human and animal health problems caused by invasive Prosopis trees. This includes flesh injuries, dental and gastric problems, and the facilitation of malaria. This review summarizes and enhances the existing knowledge about Prosopis flowering phenology, aeroallergen, and other human and animal health risks associated with this noxious plant.
- ItemInvestigating the effects of management practice on mammalian co-occurrence along the West Coast of South Africa(2020) Winterton, D.J.; van Wilgen, N.J.; Venter, J.A.The subtle and cascading effects (e.g., altered interspecific interactions) that anthropogenic stressors have on local ecological assemblages often go unnoticed but are concerning given their importance in ecosystem function. For example, elimination of buffalo from the Serengeti National Park is suggested to have driven increased abundance of smaller antelope as a result of release from competition. The perceived low abundance of small antelope in the contractual Postberg section of the West Coast National Park (the park) has been an ongoing management concern which has been anecdotally attributed to predation by a mesopredator (the caracal, Caracal caracal). However, we hypothesized that the historical overstocking, and consequent overgrazing by larger-bodied managed ungulates would influence small antelope abundance. Using camera traps, we investigated species co-occurrence and temporal activity between small antelope, managed ungulates and caracals in Postberg as well as another part of the park (Langebaan) and a farm outside of the park. Results suggest that small antelope and managed ungulates have a high degree of temporal overlap (Delta = 0.74, 0.79 and 0.86 for the farm, Langebaan and Postberg respectively), while temporal partitioning between small antelope and caracal is apparent (Delta = 0.59). Further, small antelope and managed ungulates appear to occur independently of one another (SIF = 0.91-1 across areas). Managed ungulates were detected almost three times more frequently on fallow lands when compared to the more vegetated sites within the park suggesting that segregated food/cover resources allow for independent occurrence. Small antelope had a much higher probability of occurrence outside of the protected area (e.g., psi = 0.192 and 0.486 for steenbok at Postberg, Langebaan compared to 0.841 on the farm), likely due to less variable (more intact) habitat outside of the protected area. There is not sufficient evidence to currently warrant management intervention for predators. The small size of the protected area provides limited scope for spatial replication thus reducing possibilities to infer the cause and effect for complex interactions (which would historically have taken place over much larger areas) with negative implications for adaptive management. We recommend continued monitoring over multiple seasons and a wider area to determine the spatial information requirements to inform management of small protected areas.
- ItemMake open access publishing fair and transparent!(2020) Essl, F.; Courchamp, F.; Dullinger, S.; Jeschke, J.M.; Schindler, S.The scientific publication landscape has dramatically changed in environmental sciences (and beyond) since the onset of this millennium by two closely interconnected trends: the widespread emergence of online-only journals that drastically reduced the costs for scientific publishers (Van Noorden 2013) and the increasing success of open access (OA) publishing journals (Tennant et al. 2016)—that is, journals that have reversed the revenue generation from a reader-pays to an author-pays approach. In principle, there are four avenues of OA publishing (table 1): An increasing number of journals have been established that solely publish OA (gold OA); the vast majority of these journals are online only.
- ItemRole of diversification rates and evolutionary history as a driver of plant naturalization success(2021) Lenzner, B.; Magallon, S.; Dawson, W.; Kreft, H.; Konig, C.; Pergl, J.; Pysek, P.; Weigelt, P.; van Kleunen, M.; Winter, M.; Dullinger, S.; Essl, F.Human introductions of species beyond their natural ranges and their subsequent establishment are defining features of global environmental change. However, naturalized plants are not uniformly distributed across phylogenetic lineages, with some families contributing disproportionately more to the global alien species pool than others. Additionally, lineages differ in diversification rates, and high diversification rates have been associated with characteristics that increase species naturalization success. Here, we investigate the role of diversification rates in explaining the naturalization success of angiosperm plant families. We use five global data sets that include native and alien plant species distribution, horticultural use of plants, and a time-calibrated angiosperm phylogeny. Using phylogenetic generalized linear mixed models, we analysed the effect of diversification rate, different geographical range measures, and horticultural use on the naturalization success of plant families. We show that a family's naturalization success is positively associated with its evolutionary history, native range size, and economic use. Investigating interactive effects of these predictors shows that native range size and geographic distribution additionally affect naturalization success. High diversification rates and large ranges increase naturalization success, especially of temperate families. We suggest this may result from lower ecological specialization in temperate families with large ranges, compared with tropical families with smaller ranges.