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See detailIntraspecific variation of copper tolerance of four endemic plant species from the katangan Copperbelt (D. R. Congo)
Boisson, Sylvain ULg; garin, olivier; Seleck, Maxime ULg et al

Conference (2014, August 04)

Harsh ecosystems are at the origin of speciation processes in plant communities. In metalliferous areas, plants develop physiological adaptations to tolerate metal excesses which lead to high species and ... [more ▼]

Harsh ecosystems are at the origin of speciation processes in plant communities. In metalliferous areas, plants develop physiological adaptations to tolerate metal excesses which lead to high species and population diversity. South of the Katanga province (D.R. Congo), plant communities occur on soils with one of the world’s largest concentrations of copper and cobalt. More than 600 species including 54 endemics are distributed along a copper gradient (up to 10 000 mg kg-1 available Cu) and the populations are isolated on more than 100 copper hills scattered in miombo forest. In order to improve restoration strategies of threatened species, we aimed to identify intraspecific copper tolerance of 4 endemic plant species from katangan copper outcrops: Crotalaria cobalticola, Diplolophium marthozianum, Gladiolus ledoctei and Triumfetta welwitschii. Seeds were collected in 3 different populations in the katangan Copperbelt and sown according three soil contamination modalities: control (no addition of Cu), 100 mg kg-1 and 1000 mg kg-1 of Cu concentration using hydrated copper (II) sulfate. For each combination (species x populations x soils), we had 10 repetitions. For each population, sample of 5 seeds was weighed before seedling in pot in November 2013. One individual by pot was kept for measures. Height (cm), number of leaves, number of flowers and number of fruits were measured once a week during one rainy season. For all species, no significant difference of copper tolerance appeared between populations. In contrast, populations had distinct germination rate and growth rate, especially for T. welwitshii and D. marthozianum. C. cobalticola grew significantly better in highly contaminated soil than other soils. G. ledoctei did not show any significant difference between populations and soil treatments. [less ▲]

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See detailVariation des traits fonctionnels le long d’un gradient de cuivre et cobalt : contribution du remplacement d’espèces et de la variabilité intraspécifique
Delhaye, Guillaume; Violle, Cyril; Seleck, Maxime ULg et al

Conference (2014, April)

Les collines cuprocobaltifères du Katanga sont des lieux privilégiés pour étudier la variation des traits fonctionnels le long de gradients de stress métallique. Nous avons étudié la variation de six ... [more ▼]

Les collines cuprocobaltifères du Katanga sont des lieux privilégiés pour étudier la variation des traits fonctionnels le long de gradients de stress métallique. Nous avons étudié la variation de six traits à l’échelle des espèces et de la communauté le long d’un gradient de cuivre et cobalt. D’autres paramètres tels que la concentration en phosphore et l’humidité du sol covarient positivement avec la teneur en métal du sol. Les contributions relatives du remplacement d’espèces et de la variabilité intraspécifique à la variabilité totale des traits dans les communautés ont été déterminées. A l’échelle de la communauté, la hauteur et la surface foliaire diminuent alors que les valeurs des quatre autres traits augmentent le long du gradient. Les espèces montrent des réponses variées, généralement non significatives. Pour tous les traits, le remplacement d’espèce est le moteur principal de la variation au sein des communautés. La concentration en métal du sol implique des réponses variées sur les différents traits et les différentes espèces. Nous montrons que la concentration croissante en métal privilégie le remplacement d’espèce par rapport à la variation intraspécifique et que les espèces répondent par différentes stratégies de tolérance à la concentration en métal du le sol. La variation des traits à l’échelle des communautés est essentiellement le reflet d’un changement dans les abondances des différentes formes de vie. Les espèces à xylopodes sont dominantes sur sol pauvre en métal alors que les annuelles sont dominantes sur sol très enrichi. [less ▲]

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See detailRealized niche of eight endemic plant species of Katangan Copperbelt (D.R. Congo): implications for copper species conservation
Boisson, Sylvain ULg; Seleck, Maxime ULg; Lebrun, Julie et al

Poster (2014, February 07)

South of the Katanga province (D.R. Congo), a unique vegetation grows on soils developed on 100 Cu-Co outcrops among the most important in the world (katangan Copperbelt). These outcrops form of isolated ... [more ▼]

South of the Katanga province (D.R. Congo), a unique vegetation grows on soils developed on 100 Cu-Co outcrops among the most important in the world (katangan Copperbelt). These outcrops form of isolated hills in the landscape hosting vegetal communities evolving along the mineralization gradient. More than 600 metallophytes can be found in these communities with some 32 strict endemics solely known from mineralized soils. These species present physiological and biological adaptations allowing them to tolerate toxic levels of metals in soils. The unique characteristics of most endemics are seriously threatened by the intense mining activities in the region thus also threatening the high genetic potential to be used in development of polluted soils’ restoration strategies. In an effort to characterize the ecology of these species, we model ecological niches of eight endemic species along copper-cobalt gradients. For each species, three sites were prospected and transects set. Along these, five plots where the species occurred were selected: at both the extremities of the gradient and at 1st quartile, median and 3rd quartile. In each plot, individuals of the particular species were counted and composite soil samples collected. Available EDTA Cu-Co values were determined and niches modeled for both metals through the kernel density method in R 3.0.1 (package ‘vioplot’). Results show that ecological niches of the selected endemics are distributed between Cu-soil values of 50 and 11 000 mg.kg-1 and between Co values between four and 1500 mg.kg-1. Six species occur in the lower 100 mg.kg-1concentrations of Co. As for the Cu gradient, two species present ecological optimums over 3000 mg.kg-1. This variation of ecological niches along the gradients indicates a need of adequacy between species conservation strategies and soils’ metal contents. Four of the eight studied species should be conserved on soils contaminated with some 500 mg Cu.kg-1 and 30 mg Co.kg-1. For others, precise conservation actions need to be undertaken. [less ▲]

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See detailCarrières & Biodiversité - Les pelouses sèches
Harzé, Mélanie ULg; Boisson, Sylvain ULg; Halford, Mathieu ULg et al

Learning material (2014)

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See detailCarrières & Biodiversité - Les plantes invasives
Halford, Mathieu ULg; Boisson, Sylvain ULg; Harzé, Mélanie ULg et al

Learning material (2014)

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See detailCarrières & Biodiversité - Les plans d'eau
Boisson, Sylvain ULg; Harzé, Mélanie ULg; Halford, Mathieu ULg et al

Learning material (2014)

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See detailCarrières & Biodiversité - Les falaises et éboulis
Seleck, Maxime ULg; Boisson, Sylvain ULg; Harzé, Mélanie ULg et al

Learning material (2014)

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See detailCarrières & Biodiversité - Les arènes minérales
Piqueray, Julien; Boisson, Sylvain ULg; Halford, Mathieu ULg et al

Learning material (2014)

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See detailChemical soil factors influencing plant assemblages along copper-cobalt gradients: implications for conservation and restoration
Seleck, Maxime ULg; Bizoux, Jean-Philippe ULg; Colinet, Gilles ULg et al

in Plant and Soil (2013), 373

Aims Define the chemical factors structuring plant communities of three copper-cobalt outcrops (Tenke-Fungurume, Katangan Copperbelt, D. R. Congo) presenting extreme gradients. Methods To discriminate ... [more ▼]

Aims Define the chemical factors structuring plant communities of three copper-cobalt outcrops (Tenke-Fungurume, Katangan Copperbelt, D. R. Congo) presenting extreme gradients. Methods To discriminate plant communities, 172 vegetation records of all species percentage cover were classified based on NMDS and the Calinski criterion. Soil samples were analyzed for 13 chemical factors and means compared among communities with ANOVA. Partial canonical correspondence analysis (pCCA) was used to determine amount of variation explained individually by each factor and site effect. Results Seven communities were identified. Six of the studied communities were related to distinct sites. Site effect (6.0 % of global inertia) was identified as the most important factor related to plant communities’ variation followed by Cu (5.5 %), pH (3.6 %) and Co (3.5 %). Unique contribution of site effect (3.8 %) was higher than that of Cu (1.1 %) and Co (1.0 %). Conclusions In restoration, not only Cu and Co contents will be important to maintain vegetation diversity, attention should also be given to co-varying factors potentially limiting toxicity of metals: pH, organic matter, Ca and Mn. Physical parameters were also identified as important in the creation of adequate conditions for diverse communities. Further studies should focus on the effect of physical parameters and geology. [less ▲]

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See detailCes essences importantes que l’on retrouve en forêt claire (miombo)
Hick, Aurélie ULg; Hallin, Maud; Kizika Wimana, Pacifique et al

Poster (2013, November 29)

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See detailPlant ecological niche distribution along heavy metal gradients
Boisson, Sylvain ULg; Monty, Arnaud ULg; Seleck, Maxime ULg et al

Conference (2013, June 26)

Why species do not occur everywhere? The concept of ecological niche is central to understand relationships among biotic/abiotic factors and species distribution. Gradients of environmental stress ... [more ▼]

Why species do not occur everywhere? The concept of ecological niche is central to understand relationships among biotic/abiotic factors and species distribution. Gradients of environmental stress associated to interspecific interactions generate testable patterns of specie’s response curves. Distribution of response curves have been seldom tested along toxicity gradient, in contrast to resource gradients. On Katangan copper hills (south R.D.C.), natural copper and cobalt concentrations span a large range: 2 - 1000 mg kg-1 for cobalt and 30 - 10 000 mg kg-1 for copper. In this study, we evaluate three hypotheses related to niche distributions and shapes along metal toxic gradients: (1) Species optima are uniformly distributed over copper-cobalt gradient. (2) Realized niche width varies in relation to the niche optimum along copper and cobalt gradient. (3) Absolute values of skewness coefficient are higher when plant species optima are in the extremes of cobalt gradient with a niche tails toward mesic conditions. Realized niches of 80 taxa were modeled with general additive models (GAM) using presence/absence data in 172 1m² plots. Niche optima, niche widths and skewness coefficients were estimated from species response curves. The three hypotheses were globally validated. Three groups of species were distinguished according to their optima position along metal gradient with packed optima on intermediate concentrations suggesting higher interspecific competition in low metal concentrations. Niche width increased with metal concentrations. Highest metal tolerant plant species had broader niches. Skewness coefficient was inversely related to niche optima positions. Our study demonstrates that species distribution pattern on toxicity gradient presents similarities with resource gradient. Broad realized amplitude of species adapted to high levels of copper cobalt concentrations suggests that fundamental niche of specialist metallophytes may be larger than expected. This should be further tested in controlled conditions in association to competition tests. [less ▲]

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See detailGuide to selected miombo species regeneration (Final version 2.2)
Seleck, Maxime ULg; Hick, Aurélie ULg; Ilunga wa Ilunga, Edouard et al

Report (2013)

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See detailCopperflora.org - website
Boisson, Sylvain ULg; Lebrun, Julie ULg; Seleck, Maxime ULg et al

Textual, factual or bibliographical database (2012)

This website is intended as a place of exchange for scientists and mine managers interested in the conservation, the restoration and the taxonomy of the copper-cobalt flora.

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See detailModelling realized niche of metallophyte species along copper and cobalt gradients on Katanga copper hills
Boisson, Sylvain ULg; Seleck, Maxime ULg; Guillaume, Arielle et al

Poster (2012, February 10)

In South Central Africa were identified more than 650 plant species tolerant to heavy metals, several of which endemic to Katanga and critically endangered by mining activities. These metallophyte are ... [more ▼]

In South Central Africa were identified more than 650 plant species tolerant to heavy metals, several of which endemic to Katanga and critically endangered by mining activities. These metallophyte are distributed over a hundred hills containing high copper and cobalt concentrations (20 to 10000 mg/kg for copper and 2 to 1000 mg/kg for cobalt). To understand the response of metallophyte to heavy metals, the ecological niches of 80 cupro-cobaltophytes were modeled with general additive models (GAM). Results show that (1) three groups of species were identified according to their optimum along a metal concentrations gradient and (2) a positive relationship exists between niche amplitude and optimum copper concentration. [less ▲]

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See detailCopper-Cobalt Flora Report, Oxide Project Tenke Fungurume Mining,
Lebrun, Julie ULg; Seleck, Maxime ULg; Ilunga wa Ilunga, Edouard et al

Report (2012)

Baseline study, impact assessment and management measures for copper-cobalt habitat

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See detailBiodiversity action plans: Kabwelunono [1] and Shimbidi. Proposal: long version
Seleck, Maxime ULg; Lebrun, Julie ULg; Ilunga wa Ilunga, Edouard et al

Report (2011)

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See detailSoil-plants relations diversity in extreme ecosystems and implications for restoration: the case of the cupriferous vegetation, in Katanga, D.R. Congo
Seleck, Maxime ULg; Lebrun, Julie ULg; Piqueray, Julien ULg et al

Conference (2011, June 13)

Katangan copper and cobalt hills in the D. R. Congo are isolated ecosystems on highly toxics substrates (>10.000 ppm Cu, with strongly marked gradients). As a result, those outcrops host singular vegetal ... [more ▼]

Katangan copper and cobalt hills in the D. R. Congo are isolated ecosystems on highly toxics substrates (>10.000 ppm Cu, with strongly marked gradients). As a result, those outcrops host singular vegetal communities – with a diversity of specialized metallophytes species – related to soil metals content. Recent resumption of mining activities in the area threatens those ecosystems. To allow the restoration of those communities a fine understanding of the relationship maintained with the edaphic factors is required, as well as a characterization of the intra and inter sites variation. Three outcrops have been studied on the basis of a systematic grid, following the a priori trace elements gradient. In 1m² quadrats, a composite soil sample (0-15 cm depth) was taken and the cover (%) of each species of vascular plants was recorded. Soils were analyzed for pH, C, N, and bioavailables Cu, Co, Zn, Mn, Fe, K, Mg, Ca and P. The cluster analysis and Canonical Correspondence Analysis show that different sites present different soil conditions and vegetation. Concentrations in Cu are an important explicative factor of the flora’s variation but gradients in others edaphic parameters (pH, Mg, Mn, K, Ca) appear to be essential. However, parameters explaining the diversity of communities vary from one site to another indicating a great diversity of those ecosystems and the need to develop restoration strategies relevant for each site. [less ▲]

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