Uses of GBIF in scientific research

Peer-reviewed research citing GBIF as a data source, with at least one author from South Africa.
Extracted from the Mendeley GBIF Public Library.

List of publications

  • Cramer, M., Barger, N.

    Are Namibian "fairy circles" the consequence of self-organizing spatial vegetation patterning?

    PloS ONE 8(8) e70876.

    Causes of over-dispersed barren "fairy circles" that are often surrounded by ca. 0.5 m tall peripheral grasses in a matrix of shorter (ca. 0.2 m tall) grasses in Namibian grasslands remain mysterious. It was hypothesized that the fairy circles are the consequence of self-organizing spatial vegetation patterning arising from resource competition and facilitation. We examined the edaphic properties of fairy circles and variation in fairy circle size, density and landscape occupancy (% land surface) with edaphic properties and water availability at a local scale (<50 km) and with climate and vegetation characteristics at a regional scale. Soil moisture in the barren fairy circles declines from the center towards the periphery and is inversely correlated with soil organic carbon, possibly indicating that the peripheral grass roots access soil moisture that persists into the dry season within fairy circles. Fairy circle landscape occupancy is negatively correlated with precipitation and soil [N], consistent with fairy circles being the product of resource-competition. Regional fairy circle presence/absence is highly predictable using an empirical model that includes narrow ranges of vegetation biomass, precipitation and temperature seasonality as predictor variables, indicating that fairy circles are likely a climate-dependent emergent phenomenon. This dependence of fairy circle occurrence on climate explains why fairy circles in some locations may appear and disappear over time. Fairy circles are only over-dispersed at high landscape occupancies, indicating that inter-circle competition may determine their spacing. We conclude that fairy circles are likely to be an emergent arid-grassland phenomenon that forms as a consequence of peripheral grass resource-competition and that the consequent barren circle may provide a resource-reservoir essential for the survival of the larger peripheral grasses and provides a habitat for fossicking fauna.

  • Ferrer-Paris, J., SĂĄnchez-Mercado, A., Viloria, Ă., Donaldson, J.

    Congruence and Diversity of Butterfly-Host Plant Associations at Higher Taxonomic Levels

    (Journal name unavailable from Mendeley API. To be updated soon...)

    We aggregated data on butterfly-host plant associations from existing sources in order to address the following questions: (1) is there a general correlation between host diversity and butterfly species richness?, (2) has the evolution of host plant use followed consistent patterns across butterfly lineages?, (3) what is the common ancestral host plant for all butterfly lineages? The compilation included 44,148 records from 5,152 butterfly species (28.6% of worldwide species of Papilionoidea) and 1,193 genera (66.3%). The overwhelming majority of butterflies use angiosperms as host plants. Fabales is used by most species (1,007 spp.) from all seven butterfly families and most subfamilies, Poales is the second most frequently used order, but is mostly restricted to two species-rich subfamilies: Hesperiinae (56.5% of all Hesperiidae), and Satyrinae (42.6% of all Nymphalidae). We found a significant and strong correlation between host plant diversity and butterfly species richness. A global test for congruence (Parafit test) was sensitive to uncertainty in the butterfly cladogram, and suggests a mixed system with congruent associations between Papilionidae and magnoliids, Hesperiidae and monocots, and the remaining subfamilies with the eudicots (fabids and malvids), but also numerous random associations. The congruent associations are also recovered as the most probable ancestral states in each node using maximum likelihood methods. The shift from basal groups to eudicots appears to be more likely than the other way around, with the only exception being a Satyrine-clade within the Nymphalidae that feed on monocots. Our analysis contributes to the visualization of the complex pattern of interactions at superfamily level and provides a context to discuss the timing of changes in host plant utilization that might have promoted diversification in some butterfly lineages.

  • Geerts, S., Botha, P., Visser, V., Richardson, D., Wilson, J.

    Montpellier broom (Genista monspessulana) and Spanish broom (Spartium junceum) in South Africa: An assessment of invasiveness and options for management

    (Journal name unavailable from Mendeley API. To be updated soon...)

    The legumes (Fabaceae) Genistamonspessulana and Spartium junceumaremajor invaders in several other parts of theworld, but not yet so in South Africa.Wedetermine their current distributions in South Africa at different spatial scales, assess population structure (soil seed banks and size at reproduction) evaluate current manage- ment activities, and provide recommendations for control (including assessing the feasibility of nation-wide eradication). G. monspessulana occurs at nine localities in three quarter-degree cells, covering a total of 22.7 ha. S. junceum is much more widespread, occurring in 33 quarter-degree cells and is frequently cultivated in private gardens. All naturalised or invasive populations are in disturbed areas, mostly along roadsides. Once established, G. monspessulana and S. junceum accumulate large, persistent soil-stored seed banks, ranging in size between 909 and 22,727 (median 1970) seeds/m2 and 0 and 21,364 (median 455) seeds/m2 for the two species respectively. Both species resprout vigorously after cutting and stump herbicide application (60% of G. monspessulana and 43% of S. junceum plants resprouted) which necessitates regular follow-ups. We estimate that over 10 years, at a cost of about ZAR 81,000 (1 ZAR = 0.114 US$ as on 6 October 2012), G. monspessulana could be extirpated from South Africa. S. junceum is far more widespread and coupled with low effectiveness of control, abundance of seeds and seed longevity, eradication is unfeasible. We recommend that control methods used for S. junceum be improved to prevent resprouting, and that areas are managed to limit the movement of seeds and avoid further spread and establishment. Further studies are required to understand why these two species have failed to replicate the invasiveness shown in other parts of the world. ©

    Keywords: Fabaceae, Legislation, Legumes, Management, Soil seed banks, Spatial scales

  • Geerts, S., Moodley, D., Gaertner, M., Le Roux, J., McGeoch, M., Muofhe, C., Richardson, D., Wilson, J.

    The absence of fire can cause a lag phase: The invasion dynamics of Banksia ericifolia (Proteaceae)

    Austral Ecology.

    The transition from a species introduction to an invasion often spans many decades (a lag phase). However, few studies have determined the mechanisms underlying lag phases. Such a mechanistic understanding is vital if the potential ecosystem-level impacts are to be predicted and the invasion risks to be managed proactively. Here we examine Banksia ericifolia, introduced for floriculture to South Africa, as a case study. We found 18 sites where the species has been planted, with self-sustaining (naturalized) populations at four sites, and an invasive population at one site. The invasion originated from around 100 individuals planted 35 years ago; after several fires this population has grown to approximately 10 000 plants covering about 127 ha. The current invasion of B. ericifolia already has ecosystem-level impacts, for example the nectar available to bird pollinators has more than doubled, potentially disrupting native pollination networks. If fires occurred at the other naturalized sites we anticipate populations would rapidly spread and densify with invaded areas ultimately become banksia-dominated woodlands. Indeed the only site other than the invasive site where fire has occurred regularly is already showing signs of rapid population growth and spread. However, recruitment is mainly immediately post fire and no seed bank accumulates in the soil, mechanical control of adult plants is cheap and effective, and immature plants are easily detected. This study is a first in illustrating the importance of fire in driving lag phases and provides a valuable example for why it is essential to determine the mechanisms that mediate lag phases in introduced plant species. Serotinous species that have been introduced to areas where fire is suppressed could easily be misinterpreted as low risk species whilst they remain in a lag phase, but they can represent a major invasion risk.

    Keywords: biological invasion, early detection and rapid, eradication, fynbos, horticulture, proteaceae, response

  • Gildenhuys, E., Ellis, A., Carroll, S., Le Roux, J.

    The ecology, biogeography, history and future of two globally important weeds: Cardiospermum halicacabum Linn. and C. grandiflorum Sw.

    NeoBiota 19 45-65.

    Members of the balloon vine genus, Cardiospermum, have been extensively moved around the globe as medicinal and horticultural species, two of which are now widespread invasive species; C. grandiflorum and C. halicacabum. A third species, C. corindum, may also have significant invasion potential. However, in some regions the native status of these species is not clear, hampering management. For example, in South Africa it is unknown whether C. halicacabum and C. corindum are native, and this is a major constraint to on-going biological control programmes against invasive C. grandiflorum. We review the geography, biology and ecology of selected members of the genus with an emphasis on the two most widespread invaders, C. halicacabum and C. grandiflorum. Specifically, we use molecular data to reconstruct a phylogeny of the group in order to shed light on the native ranges of C. halicacabum and C. corindum in southern Africa. Phylogenetic analyses indicate that southern African accessions of these species are closely related to South American taxa indicating human-mediated introduction and/or natural long distance dispersal. Then, on a global scale we use species distribution modelling to predict potential suitable climate regions where these species are currently absent. Native range data were used to test the accuracy with which bioclimatic modelling can identify the known invasive ranges of these species. Results show that Cardiospermum species have potential to spread further in already invaded or introduced regions in Australia, Africa and Asia, underlining the importance of resolving taxonomic uncertainties for future management efforts. Bioclimatic modelling predicts Australia to have highly favourable environmental conditions for C. corindum and therefore vigilance against this species should be high. Species distribution modelling showed that native range data over fit predicted suitable ranges, and that factors other than climate influence establishment potential. This review opens the door to better understand the global biogeography of the genus Cardiospermum, with direct implications for management, while also highlighting gaps in current research.

    Keywords: Balloon vines, biological invasion, C. corindum, management, phylogeny, species distribution modelling

  • Moodley, D., Geerts, S., Richardson, D., Wilson, J.

    Different Traits Determine Introduction, Naturalization and Invasion Success In Woody Plants: Proteaceae as a Test Case

    (Journal name unavailable from Mendeley API. To be updated soon...)

    A major aim of invasion ecology is to identify characteristics of successful invaders. However, most plant groups studied in detail (e.g. pines and acacias) have a high percentage of invasive taxa. Here we examine the global introduction history and invasion ecology of Proteaceae—a large plant family with many taxa that have been widely disseminated by humans, but with few known invaders. To do this we compiled a global list of species and used boosted regression tree models to assess which factors are important in determining the status of a species (not introduced, introduced, naturalized or invasive). At least 402 of 1674 known species (24%) have been moved by humans out of their native ranges, 58 species (14%) have become naturalized but not invasive, and 8 species (2%) are invasive. The probability of naturalization was greatest for species with large native ranges, low susceptibility to Phytophthora root-rot fungus, large mammal-dispersed seeds, and with the capacity to resprout. The probability of naturalized species becoming invasive was greatest for species with large native ranges, those used as barrier plants, tall species, species with small seeds, and serotinous species. The traits driving invasiveness of Proteaceae were similar to those for acacias and pines. However, while some traits showed a consistent influence at introduction, naturalization and invasion, others appear to be influential at one stage only, and some have contrasting effects at different stages. Trait-based analyses therefore need to consider different invasion stages separately. On their own, these observations provide little predictive power for risk assessment, but when the causative mechanisms are understood (e.g. Phytophthora susceptibility) they provide valuable insights. As such there is considerable value in seeking the correlates and mechanisms underlying invasions for particular taxonomic or functional groups. Cit

    Keywords: Balloon vines, biological invasion, C. corindum, management, phylogeny, species distribution modelling

  • Allnutt, T., McClanahan, T., AndrĂ©fouĂ«t, S., Baker, M., Lagabrielle, E., McClennen, C., Rakotomanjaka, A., Tianarisoa, T., Watson, R., Kremen, C.

    Comparison of Marine Spatial Planning Methods in Madagascar Demonstrates Value of Alternative Approaches

    (Journal name unavailable from Mendeley API. To be updated soon...)

    The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the “strict protection” class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during initial stages of the planning process. Choosing an appropriate approach ultimately depends on scientific and political factors including representation targets, likelihood of adoption, and persistence goals.

    Keywords: Balloon vines, biological invasion, C. corindum, management, phylogeny, species distribution modelling

  • Barbosa, F., Pillar, V., Palmer, A., Melo, A.

    Predicting the current distribution and potential spread of the exotic grass Eragrostis plana Nees in South America and identifying a bioclimatic niche shift during invasion

    Austral Ecology online no-no.

    Eragrostis plana (Poaceae) is a perennial grass introduced from South Africa to the state of Rio Grande do Sul in southern Brazil. Currently, it is considered an invasive grass in several regions of the world, including South America, where it has caused negative ecological and socio-economic impacts. Ecological niche models, using bioclimatic variables, are often used to predict the potential distribution of invasive species. In this study we prepared two bioclimatic models for E. plana using the Genetic Algorithm for Rule-set Production, the first based on data from its native region (South Africa) and the second on data from both the native and invaded (South America) regions.We then projected each model onto South America to identify regions vulnerable to invasion by the species, and compared our results with available records of the species in South America. Finally, we explored the model’s predictions for the existence of a bioclimatic niche shift during the invasion process of E. plana in South America, using multivariate statistical analysis. The model created with native distribution data was only able to predict (with highly suitable habitat) the region of introduction of E. plana in South America.However, the current distribution, as well as the region of introduction of the species, was reliably predicted by the model created with data from both native and invaded regions. Our multivariate analysis supports a hypothesis of bioclimatic niche shift during the invasion process of E. plana in South America.

    Keywords: bioclimatic variable, ecological niche model, garp, invasive grass, native pasture

  • DomĂ­nguez Lozano, F., Rebelo, A., Bittman, R.

    How plant inventories improve future monitoring

    Biodiversity and Conservation online.

    Plant inventories are at the heart of conservation efforts. Despite their obvious conservation values, properties of these datasets are poorly understood. We use plant databases from three different well-established inventories [rare plants in California (CA), Spanish threatened plants (SP) and the Proteaceae in South Africa (SA)] to explore the behavior of large data sets in facilitating the link between current field surveys and future standardized monitoring methods. We analyze area frequency curves of the species area size for each data set and for a series of extracted databases from each inventory. Our results show that all field surveys produced left-skewed frequency distributions. A lognormal distribution is better fitted by SA, followed by CA and finally by SP, which is least suited to a lognormal fit. Using the most threatened portion of the three floras, these general patterns still apply. Secondly, a minimum sample analysis indicates that precision increases according to sample size. Proportionally, CA data require less sampling effort than the Spanish pool and the latter require less than do SA in order to get a clear monitoring trend. Larger skewness values are related to inventories with wider scope. SA Proteas display the most skewed distribution. Skewness in California may be explained not only by the nature and scope of the inventory but also by the scale used for mapping. The Spanish database is also affected by surveyor bias towards the most endangered portion of the data set. Monitoring should take into account the original nature of each inventory. Particular inventory methods and scope may produce different outputs, constraining future monitoring programs. Key aspects are skewness and variation, and both combined could identify inventories in need of better data collection practices for more precise estimates of changes in biodiversity.

    Keywords: Categories of threat, Hollow curve, Lognormal distribution, Mediterranean plant conservation, Rarity, Sample size, Skewness, Threatened plants

  • Mokhatla, M., Measey, G., Chimimba, C., Rensburg, B.

    A biogeographical assessment of anthropogenic threats to areas where different frog breeding groups occur in South Africa: implications for anuran conservation

    Diversity and Distributions 18(5) 470-480.

    Aim To determine the spatial relationship between areas where different frog breeding groups occur and elevated anthropogenic activities, and the conservation implications thereof. Location South Africa. Methods Data on frog distribution ranges for the southern African sub-region were used to identify biogeographical areas within South Africa. A random draw technique was used to determine whether areas where different frog breeding groups occur were characterized by higher levels of anthropogenic threats than expected by chance. Four measures (human population density, percentage land transformation, percentage protected area and invasive alien plants richness) expected to reflect threats were analysed. Results Terrestrial-breeders were more often spatially associated with areas of threat than expected by chance in three of the seven biogeographical regions examined with land transformation and invasive alien plant richness being most significant. The south central was the only region where terrestrial-breeders were spatially congruent with protected areas. Areas where stream-breeders occur were spatially congruent with anthropogenic threats (with alien plants being most consistent) in five of the seven regions examined while protected areas were well represented in four of the seven regions. Non-significant results were found for permanent and temporary aquatic-breeders at both the national and the biogeographical scale. Main conclusions By analysing data at the sub-continental scale we were able to identify regional threats to amphibians traditionally classified at species-specific scales. Our study recognized land transformation and alien invasive plants as significant threats to areas important for the long-term breeding success of stream and terrestrial amphibians in South Africa. Areas where different breeding groups occur in the south-western Cape showed the greatest spatial congruence with the threats examined. Areas where terrestrial breeding frogs occur are not well represented in the current conservation network. This has important implications in addressing the current status of threats on amphibians in a biogeographical context.

    Keywords: Amphibians, anthropogenic threats, biogeographical scale, life-history traits, national scale, protected areas network, South Africa