Context-dependency in carnivore co-occurrence across a multi-use conservation landscape

This research was funded by South Africa's National Research Foundation (UID: 107099 and 115040), African Institute for Conservation Ecology, National Geographic Society (EC-314R-18) and Wild Tomorrow Fund. G.C.-S. and M.S.-R. were funded by Fundacão para a Ciência e a Tecnologia in the frame of a doctoral grant (PD/BD/114037/2015) and the research unit (UID/BIA/00329/2019), respectively.Carnivore intraguild dynamics depend on a complex interplay of environmental affinities and interspecific interactions. Context-dependency is commonly expected with varying suites of interacting species and environmental conditions but seldom empirically described. In South Africa, decentralized approaches to conservation and the resulting multi-tenure conservation landscapes have markedly altered the environmental stage that shapes the structure of local carnivore assemblages. We explored assemblage-wide patterns of carnivore spatial (residual occupancy probability) and temporal (diel activity overlap) co-occurrence across three adjacent wildlife-oriented management contexts?a provincial protected area, a private ecotourism reserve, and commercial game ranches. We found that carnivores were generally distributed independently across space, but existing spatial dependencies were context-specific. Spatial overlap was most common in the protected area, where species occur at higher relative abundances, and in game ranches, where predator persecution presumably narrows the scope for spatial asymmetries. In the private reserve, spatial co-occurrence patterns were more heterogeneous but did not follow a dominance hierarchy associated with higher apex predator densities. Pair-specific variability suggests that subordinate carnivores may alternate between pre-emptive behavioral strategies and fine-scale co-occurrence with dominant competitors. Consistency in species-pairs diel activity asynchrony suggested that temporal overlap patterns in our study areas mostly depend on species' endogenous clock rather than the local context. Collectively, our research highlights the complexity and context-dependency of guild-level implications of current management and conservation paradigms; specifically, the unheeded potential for interventions to influence the local network of carnivore interactions with unknown population-level and cascading effects.Publisher PDFPeer reviewe

Implementation of a reference standard and proficiency testing programme by the World Wide Antimalarial Resistance Network (WWARN)

<p>Abstract</p> <p>Background</p> <p>The Worldwide Antimalarial Resistance Network (WWARN) is a global collaboration to support the objective that anyone affected by malaria receives effective and safe drug treatment. The Pharmacology module aims to inform optimal anti-malarial drug selection. There is an urgent need to define the drug exposure - effect relationship for most anti-malarial drugs. Few anti-malarials have had their therapeutic blood concentration levels defined. One of the main challenges in assessing safety and efficacy data in relation to drug concentrations is the comparability of data generated from different laboratories. To explain differences in anti-malarial pharmacokinetics in studies with different measurement laboratories it is necessary to confirm the accuracy of the assay methods. This requires the establishment of an external quality assurance process to assure results that can be compared. This paper describes this process.</p> <p>Methods</p> <p>The pharmacology module of WWARN has established a quality assurance/quality control (QA/QC) programme consisting of two separate components:</p> <p indent="1">1. A proficiency testing programme where blank human plasma spiked with certified reference material (CRM) in different concentrations is sent out to participating bioanalytical laboratories.</p> <p indent="1">2. A certified reference standard programme where accurately weighed amounts of certified anti-malarial reference standards, metabolites, and internal standards are sent to participating bioanalytical and in vitro laboratories.</p> <p>Conclusion</p> <p>The proficiency testing programme is designed as a cooperative effort to help participating laboratories assess their ability to carry out drug analysis, resolve any potential problem areas and to improve their results - and, in so doing, to improve the quality of anti-malarial pharmacokinetic data published and shared with WWARN.</p> <p>By utilizing the same source of standards for all laboratories, it is possible to minimize bias arising from poor quality reference standards. By providing anti-malarial drug standards from a central point, it is possible to lower the cost of these standards.</p

Resensies

Book Review 1Book Title: Skollie: One man’s struggle to survive by telling storiesBook Author: John W. FredericksCape Town: Penguin Random House. 251 pp. ISBN: 978-1-77609-199-7.Book Review 2Book Title: A Gap in the HedgeBook Author: Johan Vlok LouwCape Town: Umuzi, 2017. 233 pp. ISBN: 978-1-4152-08915Book Review 3Book Title: Iziganeko zesizwe: Occasional Poems (1900–1943)Book Authors: S.E.K. Mqhayi. Eds. and trans. Jeff Opland and Peter T. MtuzePietermaritzburg: University of KwaZulu Natal Press, 2017. 469 pp. ISBN: 9781869143343; e-ISBN: 9781869143350.Book Review 4Book Title: Oorlog en terpentynBook Authors: Stefan Hertmans. Vertaal deur Daniel HugoPretoria: Protea Boekhuis, 2016. 335 pp. ISBN: 978-1-4853-0610-8; e-Boek: 978-1-4853-0722-8; Epub: 978-1-4853-0723-5.Book Review 5Book Title: Groen soos die hemel daarboBook Author: Eben VenterKaapstad: Tafelberg, 212 pp. ISBN: 978-0-624-08261-3.Book Review 6Book Title: Die wêreld van Charlie OengBook Author: Etienne van HeerdenKaapstad: Tafelberg, 2017. 559 pp. ISBN 978-0-624-08052-7.Book Review 7Book Title: Die diepblou seeBook Author: François LootsKaapstad: Umuzi, 2017. 239 pp. ISBN: 978-1-4152-0953-0.Book Review 8Book Title: Die derde spoelBook Author: S.J. NaudéKaapstad: Umuzi, 2017. 342 pp. ISBN: 978-1-4152-0747-5 (Druk). ISBN: 978-1-4152-0748-2 (ePub).Book Review 9Book Title: Nou, hierBook Author: Corné CoetzeeKaapstad: Human &amp; Rousseau, 2017. 107 pp. ISBN 978-0-7981-7620-0.Book Review 10Book Title: RadbraakBook Author: Jolyn PhillipsKaapstad: Human &amp; Rousseau, 2017. 68 pp. ISBN: 978-0-7981-7616-3.Book Review 11Book Title: VuurvasBook Author: Carel AntonissenNaledi, 2016. ISBN 978-0-928316-97-1.Book Review 12Book Title: Voor ek my kom kryBook Author: Pirow BekkerPretoria: Protea Boekhuis, 2017. 110 pp. ISBN: 978-1-4853-0648-1.Book Review 13Book Title: Nuwe stemme 6Book Authors: Bibi Slippers en Charl-Pierre Naudé (samenstellers)Kaapstad: Tafelberg, 2017. 176 pp. ISBN 9780624082644.Book Review 14Book Title: UittogboekBook Author: Johan MyburgPretoria: Protea, 2017. 100 pp. ISBN: 9781485307761.Book Review 15Book Title: Krap uit die seeBook Author: Fourie BothaPretoria: Protea Boekehuis, 2017. 64 pp. ISBN 9781485307570.Book Review 16Book Title: Skepelinge. Aanloop tot ‘n romanBook Author: Karel SchoemanKaapstad: Human &amp; Rousseau, 2017. 576 pp. ISBN: 978079817610.Book Review 17Book Title: Die reis gaan inwaarts: Die kuns van sterwe in kreatiewe werke van Karel SchoemanBook Author: Cas WepenerStellenbosch: Sun MeDIA MeTRO. Druknaam: SUN PRESS, 2017. 233 pp. ISBN: 978-1-928355-14-4 (Druk); ISBN: 979-1-928355-15-1 (e-boek)

Improved representation of plant functional types and physiology in the Joint UK Land Environment Simulator (JULES v4.2) using plant trait information

Dynamic global vegetation models are used to predict the response of vegetation to climate change. They are essential for planning ecosystem management, understanding carbon cycle–climate feedbacks, and evaluating the potential impacts of climate change on global ecosystems. JULES (the Joint UK Land Environment Simulator) represents terrestrial processes in the UK Hadley Centre family of models and in the first generation UK Earth System Model. Previously, JULES represented five plant functional types (PFTs): broadleaf trees, needle-leaf trees, C3 and C4 grasses, and shrubs. This study addresses three developments in JULES. First, trees and shrubs were split into deciduous and evergreen PFTs to better represent the range of leaf life spans and metabolic capacities that exists in nature. Second, we distinguished between temperate and tropical broadleaf evergreen trees. These first two changes result in a new set of nine PFTs: tropical and temperate broadleaf evergreen trees, broadleaf deciduous trees, needle-leaf evergreen and deciduous trees, C3 and C4 grasses, and evergreen and deciduous shrubs. Third, using data from the TRY database, we updated the relationship between leaf nitrogen and the maximum rate of carboxylation of Rubisco (Vcmax), and updated the leaf turnover and growth rates to include a trade-off between leaf life span and leaf mass per unit area. Overall, the simulation of gross and net primary productivity (GPP and NPP, respectively) is improved with the nine PFTs when compared to FLUXNET sites, a global GPP data set based on FLUXNET, and MODIS NPP. Compared to the standard five PFTs, the new nine PFTs simulate a higher GPP and NPP, with the exception of C3 grasses in cold environments and C4 grasses that were previously over-productive. On a biome scale, GPP is improved for all eight biomes evaluated and NPP is improved for most biomes – the exceptions being the tropical forests, savannahs, and extratropical mixed forests where simulated NPP is too high. With the new PFTs, the global present-day GPP and NPP are 128 and 62 Pg C year−1, respectively. We conclude that the inclusion of trait-based data and the evergreen/deciduous distinction has substantially improved productivity fluxes in JULES, in particular the representation of GPP. These developments increase the realism of JULES, enabling higher confidence in simulations of vegetation dynamics and carbon storage

The number of tree species on Earth

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global groundsourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are 73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness

The number of tree species on Earth.

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness

The number of tree species on Earth.

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness

Global variability in leaf respiration in relation to climate, plant functional types and leaf traits

• Leaf dark respiration (Rdark) is an important yet poorly quantified component of the global carbon cycle. Given this, we analyzed a new global database of Rdark and associated leaf traits. • Data for 899 species were compiled from 100 sites (from the Arctic to the tropics). Several woody and nonwoody plant functional types (PFTs) were represented. Mixed-effects models were used to disentangle sources of variation in Rdark. • Area-based Rdark at the prevailing average daily growth temperature (T) of each site increased only twofold from the Arctic to the tropics, despite a 20°C increase in growing T (8–28°C). By contrast, Rdark at a standard T (25°C, Rdark25) was threefold higher in the Arctic than in the tropics, and twofold higher at arid than at mesic sites. Species and PFTs at cold sites exhibited higher Rdark25 at a given photosynthetic capacity (Vcmax25) or leaf nitrogen concentration ([N]) than species at warmer sites. Rdark25 values at any given Vcmax25 or [N] were higher in herbs than in woody plants. • The results highlight variation in Rdark among species and across global gradients in T and aridity. In addition to their ecological significance, the results provide a framework for improving representation of Rdark in terrestrial biosphere models (TBMs) and associated land-surface components of Earth system models (ESMs)

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems