Extracted from the Mendeley GBIF Public Library.
Assis J, Zupan M, Nicastro K, Zardi G, McQuaid C, Serrão E (2015)
PloS one 10(6) e0128124.
Invasive species can affect the function and structure of natural ecological communities, hence understanding and predicting their potential for spreading is a major ecological challenge. Once established in a new region, the spread of invasive species is largely controlled by their dispersal capacity, local environmental conditions and species interactions. The mussel Mytilus galloprovincialis is native to the Mediterranean and is the most successful marine invader in southern Africa. Its distribution there has expanded rapidly and extensively since the 1970s, however, over the last decade its spread has ceased. In this study, we coupled broad scale field surveys, Ecological Niche Modelling (ENM) and Lagrangian Particle Simulations (LPS) to assess the current invaded distribution of M. galloprovincialis in southern Africa and to evaluate what prevents further spread of this species. Results showed that all environmentally suitable habitats in southern Africa have been occupied by the species. This includes rocky shores between Rocky Point in Namibia and East London in South Africa (approx. 2800 km) and these limits coincide with the steep transitions between cool-temperate and subtropical-warmer climates, on both west and southeast African coasts. On the west coast, simulations of drifting larvae almost entirely followed the northward and offshore direction of the Benguela current, creating a clear dispersal barrier by advecting larvae away from the coast. On the southeast coast, nearshore currents give larvae the potential to move eastwards, against the prevalent Agulhas current and beyond the present distributional limit, however environmental conditions prevent the establishment of the species. The transition between the cooler and warmer water regimes is therefore the main factor limiting the northern spread on the southeast coast; however, biotic interactions with native fauna may also play an important role.
Brummitt N, Bachman S, Griffiths-Lee J, Lutz M, Moat J, Farjon A et al. (2015)
Green Plants in the Red: A Baseline Global Assessment for the IUCN Sampled Red List Index for Plants.
PloS one 10(8) e0135152.
Plants provide fundamental support systems for life on Earth and are the basis for all terrestrial ecosystems; a decline in plant diversity will be detrimental to all other groups of organisms including humans. Decline in plant diversity has been hard to quantify, due to the huge numbers of known and yet to be discovered species and the lack of an adequate baseline assessment of extinction risk against which to track changes. The biodiversity of many remote parts of the world remains poorly known, and the rate of new assessments of extinction risk for individual plant species approximates the rate at which new plant species are described. Thus the question 'How threatened are plants?' is still very difficult to answer accurately. While completing assessments for each species of plant remains a distant prospect, by assessing a randomly selected sample of species the Sampled Red List Index for Plants gives, for the first time, an accurate view of how threatened plants are across the world. It represents the first key phase of ongoing efforts to monitor the status of the world's plants. More than 20% of plant species assessed are threatened with extinction, and the habitat with the most threatened species is overwhelmingly tropical rain forest, where the greatest threat to plants is anthropogenic habitat conversion, for arable and livestock agriculture, and harvesting of natural resources. Gymnosperms (e.g. conifers and cycads) are the most threatened group, while a third of plant species included in this study have yet to receive an assessment or are so poorly known that we cannot yet ascertain whether they are threatened or not. This study provides a baseline assessment from which trends in the status of plant biodiversity can be measured and periodically reassessed.
Cheek M (2015)
First official record of a naturalised population of Mimosa albida Humb. & Bonpl. ex Willd. var. albida in Africa
BioInvasions Records 4.
Mimosa albida var. albida is a woody shrub indigenous to Central and South America that is well adapted to disturbed habitats. This paper is the first formal report of this species outside of cultivation in Africa. A total of 61 plants were recorded along a 1.5km arc of the Mkhomazi River in KwaZulu-Natal, South Africa. Effort s are underway to eradicate the population.
Keywords: South Africa, ornament al plants, riparian weeds
González-Moreno P, Diez J, Richardson D, Vilà M (2015)
Global Ecology and Biogeography n/a-n/a.
Aim Analysing how species niches shift between native and introduced ranges is a powerful tool for understanding the determinants of species distributions and for anticipating range expansions by invasive species. Most studies only consider the climatic niche, by correlating widely available presence-only data with regional climate. However, habitat characteristics and disturbance also shape species niches, thereby potentially confounding shifts attributed only to differences in climate. Here we used presence and abundance data for Oxalis pes-caprae, a species native to South Africa and invading areas globally, to understand how niche shifts may be influenced by disturbance at habitat and landscape scales in addition to climate. Locality Mediterranean climate areas world-wide. Methods We used available presence-only data and also conducted extensive surveys of the abundance of Oxalis (c. 11,000 plots) across different habitats in South Africa and in the introduced range in the Mediterranean Basin. We extended principal component analysis methods for measuring niche shifts by using Bayesian generalized linear models to identify climatic and disturbance niche shifts. Results We found a large climatic niche expansion towards stronger seasonality and lower temperature in the introduced range, but this expansion was greatly reduced when considering only conditions available in both ranges. Oxalis occupied more natural landscapes in the native range that remained unoccupied in the introduced range (‘niche unfilling’). In contrast to the similar abundances in natural and disturbed habitats in its native range, Oxalis was more abundant in disturbed habitats in the introduced range. Conclusions The large climatic niche expansion most likely reflects significant plasticity of Oxalis rather than rapid evolution. Furthermore, the unfilling of its disturbance niche in the introduced range suggests high potential for further invasion of natural areas. Together, these findings suggest that the potential for future spread of invasive species may be underestimated by approaches that characterize species niches based only on climate or partial information about their distributions.
Keywords: Bayesian, Oxalis pes-caprae, biological invasions, invasion risk, niche conservatism, non-native species, reciprocal distribution modelling
Jaca TP P (2015)
Flowering Plants of Africa 64 76-83.
Abutilon , established by Miller (1754), is a large genus in the Malvaceae family with more than 200 species. The Malvaceae are traditionally placed in the order Malvales, which includes important families such as Tiliaceae, Sterculiaceae and Bombacaceae (Mitchell 1982). The Malvales is a large and important natural order with its members found throughout the world, except in the Arctic regions (Masters 1868). These families are linked together by similarities in floral and pollen mor - phology, wood anatomy (Metcalfe & Chalk 1950; Manchester & Miller 1978) and leaf structure (Manchester 1992). Recent studies in molecular systematics also confirm these similarities among these four families, although phylogenetic relationship within the families remains unclear (Alverson et al . 1999)
Keywords: Bayesian, Oxalis pes-caprae, biological invasions, invasion risk, niche conservatism, non-native species, reciprocal distribution modelling
Jacobs, L. E. O., van Wyk, E., Wilson J (2015)
Recent discovery of small naturalised populations of Melaleuca quinquenervia (Cav.) S.T. Blake in South Africa
BioInvasions Records ( 4.
The discovery of a naturalised population of Melaleuca quinquenervia in South Africa in 2009 prompted an evaluation of the species’ distribution across South Africa. We found reco rds at seven localities in two of the nine provinces of South Africa, with natur alised populations at two sites — ~300 plants were discovered over 0.3ha in a confined-seep on a mountain slope, while at an old arboretum 12 large, planted trees and 9 naturalised trees were found. An additional herbarium record from Mozambique suggests that this glob al invader is present at other sites within the sub-region, and so while th e extirpation of populations in South Africa is recommended and lo oks feasible, further work is required to de termine the status and evaluate whether eradica tion from the sub-region as a whole is possible.
Keywords: Myrta, early detection, eradication, invasive tree
Richardson D, Le Roux J, Wilson J (2015)
Australian acacias as invasive species: lessons to be learnt from regions with long planting histories
Southern Forests: a Journal of Forest Science 1-9.
Problems associated with invasiveness of non-native tree species used in forestry are increasing rapidly worldwide and are most severe in areas with a long history of plantings. Lessons learnt in areas with long histories of plantings and invasions may be applicable to areas with shorter planting histories. Most research towards understanding such tree invasions has focused on Pinus species, though all groups of trees that have been widely used in forestry are invasive to some extent. This paper explores the experience of Australian Acacia species (wattles). Unlike some other groups of trees, no particular set of traits clearly separates highly invasive from less- or non-invasive wattles. All species that have been widely planted over a long period have become invasive; the extent of invasions is largely a function of human usage. These findings imply that propagule pressure in concert with residence times are the main drivers of invasiveness in wattles (many factors mediate these drivers, including fire,...
Keywords: biological invasions, forestry, sustainable forestry, tree invasions, wattles
Zengeya T, Booth A, Chimimba C (2015)
Broad Niche Overlap between Invasive Nile Tilapia Oreochromis niloticus and Indigenous Congenerics in Southern Africa: Should We be Concerned?
Entropy 17(7) 4959-4973.
This study developed niche models for the native ranges of Oreochromis andersonii, O. mortimeri, and O. mossambicus, and assessed how much of their range is climatically suitable for the establishment of O. niloticus, and then reviewed the conservation implications for indigenous congenerics as a result of overlap with O. niloticus based on documented congeneric interactions. The predicted potential geographical range of O. niloticus reveals a broad climatic suitability over most of southern Africa and overlaps with all the endemic congenerics. This is of major conservation concern because six of the eight river systems predicted to be suitable for O. niloticus have already been invaded and now support established populations. Oreochromis niloticus has been implicated in reducing the abundance of indigenous species through competitive exclusion and hybridisation. Despite these well-documented adverse ecological effects, O. niloticus remains one of the most widely cultured and propagated fish species in aquaculture and stock enhancements in the southern Africa sub-region. Aquaculture is perceived as a means of protein security, poverty alleviation, and economic development and, as such, any future decisions on its introduction will be based on the trade-off between socio-economic benefits and potential adverse ecological effects.
Keywords: Nile tilapia, conservation, ecological niche modelling, indigenous fishes, invasion, southern Africa
van Kleunen M, Dawson W, Essl F, Pergl J, Winter M, Weber E et al. (2015)
Nature 525(7567) 100-103.
All around the globe, humans have greatly altered the abiotic and biotic environment with ever-increasing speed. One defining feature of the Anthropocene epoch1, 2 is the erosion of biogeographical barriers by human-mediated dispersal of species into new regions, where they can naturalize and cause ecological, economic and social damage3. So far, no comprehensive analysis of the global accumulation and exchange of alien plant species between continents has been performed, primarily because of a lack of data. Here we bridge this knowledge gap by using a unique global database on the occurrences of naturalized alien plant species in 481 mainland and 362 island regions. In total, 13,168 plant species, corresponding to 3.9% of the extant global vascular flora, or approximately the size of the native European flora, have become naturalized somewhere on the globe as a result of human activity. North America has accumulated the largest number of naturalized species, whereas the Pacific Islands show the fastest increase in species numbers with respect to their land area. Continents in the Northern Hemisphere have been the major donors of naturalized alien species to all other continents. Our results quantify for the first time the extent of plant naturalizations worldwide, and illustrate the urgent need for globally integrated efforts to control, manage and understand the spread of alien species.
Keywords: Biodiversity, Biogeography, Invasive species, Macroecology
Blanchard R, O'Farrell P, Richardson D (2014)
Anticipating potential biodiversity conflicts for future biofuel crops in South Africa: incorporating spatial filters with species distribution models
GCB Bioenergy Forthcoming.
Liquid biofuel production will likely have its greatest impact through the large-scale changes in land use that will be required to meet the production of this energy source. In this study, we develop a framework which integrates species distribution models, land cover, land capability and various biodiversity conservation data to identify natural areas with (i) a potentially high risk of transformation for biofuel production and (ii) potential impact to biodiversity conservation areas. The framework was tested in the Eastern Cape of South Africa, a region which has been earmarked for the cultivation of biofuels. We expressly highlight the importance of biodiversity conservation data that enhance the protected area network to limit potential losses by comparing the overlap of areas likely to become cultivated with (i) protected areas; (ii) biodiversity hot spots not currently protected; and (iii) ‘ecological corridors’ (areas deemed important for the migration of species and linkages between important biodiversity areas). Results indicate that the introduction of spatial filters reduced available land from 54% to 45%. Including all biodiversity scenarios reduced available land to 15% of the Eastern Cape should avoiding conflict with biodiversity conservation areas be prioritized. The assumption that agriculturally marginal land offers a unique opportunity to be converted to biofuel crops does not consider the biodiversity value attached to these areas. We highlight that decisions relating to large-scale transformation and changes in land cover need to take account of broader ecological processes. Determining the spatial extent of threats to biodiversity facilitates the analysis of spatial conflict. This article demonstrates a proactive approach for anticipating likely habitat transformation and provides an objective means of mitigating potential conflict with existing land use and biodiversity.
Keywords: MaxEnt, agricultural land, biodiversity, bioenergy crops, conflict, land suitability, spatial analysis, spatial filters