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Prof Edward Witkowski

PROF Edward Witkowski

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BSc Honours (Witwatersrand), MSc (Witwatersrand), PhD (Cape Town)

011 717 1000
edward.witkowski@wits.ac.za
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Teaching

  • Ecological Communities and Biodiversity Conservation (ECBC) (second & third year students)
  • Cape Vidal Field Trip (third year students)
  • Experimental Design and Biostatistics (honours)
  • Computer statistics (honours and post-graduates)
  • Plant Population Dynamics and Regeneration Ecology (PPDARE) (honours)
  • Conserving Biodiversity for the coursework MSc ?Resource Conservation Biology *(RCB) (post-graduates and others).

Current post-graduate students: PhD

Mr. Bradley G. Wilson. PhD (Jan 2003). Population dynamics and regeneration of selected woody spp. in the Kruger National Park. KNP Mellon awardee.

Ms. Marilyn Govender PhD (June 2003). Identification of spatial differences in dry season water status and groundwater access in trees growing above contaminated groundwater plumes originating from gold tailings dams. Co-supervised with Dr. P. Dye.

Ms. Selma Nangulah PhD (Jan 2005) The contribution of plant resources to the livelihood of rural communities in conservancies in Namibia. Rangeland management and resource use, and combining crop production and livestock farming using traditional knowledge systems in the Northern Namibia.

Mr. Markus Reichardt PhD (Mar 2005) A History of Mine Waste Rehabilitation Science in South Africa.

Ms. Vettes Kalema (August 2005). Diversity, use and regeneration potential of highly utilized charcoal tree species in a multiple land-use equatorial savanna dryland, Uganda. Co-supervised with Dr. B. Erasmus.

Ms Helen Farmer (Jan 06). A comparison of herbivore impact at different densities of artificial water availability: implications for conservation management. Co-supervised with Dr. M. Peel.

Ms Lisa Buccellato (Jan 05). Antagonistic versus synergistic interactions between multiple biocontrol agents released against invasive alien plants. A case study of a stem gall fly, Procecidochares utilis, and a leaf-spot pathogen, Phaeoramularia eupatorii-odorati, released against crofton weed, Ageratina adenophora, in South Africa. Co-supervised with Prof. Marcus Byrne

Ms. Cathy Dzerefos (July 05). (Dr. Rob Toms, supervisor). Distribution, density and utilisation of edible stink-bugs (Encosternum delegorguei), a traditional food in the Limpopo Province, South Africa. Co-supervised with Dr. Rob Thoms.

Ms. Kaera Coetzer (Jan 06). Identifying conservation threats and prioritising protected area biodiversity conservation in the Central Lowveld, South Africa. Co-supervised with Dr. B. Erasmus.

Mr. Jeremy Goodall (June 2007). Ecology and control of pompomweed Campuloclinium macrocephalum (Less.) DC in South Africa.

Mrs. Sarah Venter (2008). Population ecology and sustainable harvesting of Baobab in Venda.

Mr. Erich van Wyk (2008). Ex-situ conservation and the Millenium seed bank project (MSBP). Co-supervisor, Dr Paul Smith (Head MSBP), Kew Gardens, UK.

Current post-graduate students: MSc

Ms. Renee van rde. MSc (Jan 2004). Assessing the vegetating of slopes of gold slimes dams. Co-supervised with Ms. I. Weiersbye.

Mr. Greg Martindale MSc (Jan 2005). Impacts of livestock grazing on plant diversity in the grassland biome. Co-supervisor Dr. TG O?Connor.

Ms. Taryn Morris (Jan 06). The impacts of invasive alien plant clearing on riparian vegetation recovery along the Sabie River in the Kruger National Park. NRF Prestigious Bursary awardee. Co-supervisor Dr. Julie Coetzee.

Ms. Samanta Stelli MSc (July 2005). The role of soil seed banks in the regeneration of certain Acacia species in the Kruger National Park, South Africa.

Ms. Tracey Gardiner (Oct 06, PT). Population Biology and Ecology of Melolobium subspicatum, an Endangered plant, endemic to the Gauteng Province of South Africa. Co-supervised with Michele Pfab.

Ms. Faith Kaliballa (Jan 06). The performance of the seed feeding bruchid beetle Sulcobruchus subsuturalis (Pic) (Coleoptera: Bruchidae) in the biological control of Caesalpinia decapetala (Roth) Alston (Fabaceae) an invasive weed in South Africa. Co-supervisor Prof. Marcus Byrne.

Mr. Rowan van Tonder (Mar 06; University of Limpopo). Conservation biology of the endangered Euphorbia groenwaldii. Co-supervised with Dr. Derek Engelbrecht.

Ms. Shelley Currin (Jan 08). RCB ? Veld condition monitoring in the Serengeti. Co-supervisor Dr. Peter Goodman

Mr. Brian Whitfield. Infectivity of mycorrhizal innocula in obligate and facultative mycotropic plants growing in gold slimes. MSc (Feb. 2000). Co-supervised with Dr. C. Straker.

Mr. Mervin C. Lotter. MSc (Jan 2003). Development and testing of an objective systems and procedural approach to redesign a Threatened Plant Programme for Mpumalanga Province. Co-supervised with Prof. L. Mucina.

Ms. Sinah Seeletsi. MSc (Jan 2003). Tannin contents of leaves and bark of 6 Acacia species growing on slimes dams and their economic value. Co-supervised with Ms. I. Weiersbye. Awarded The Canon Collins Educational Trust for South Africa (CCETSA) Bursary (R20 000).

Mr. Greg Martindale MSc (Jan 2005). Grassland Biome conservation through appropriate management of rangelands.

Ms. Samanta Stelli MSc (Jan 2005). Growth and survival of trees in pot culture and on the tops of gold slimes dam.

Graduated post-graduate students

MSc

Ms. Catherine Dzerefos (1997). The distribution, availability, growth and establishment of mistletoe species in the central eastern Transv l Lowveld. Freelance ecol./ethnobotanical consultant, and Research Officer at Wits (2000) (co-supervised with Prof. C. Shackleton)

Ms. Bronwen Griffiths (1996). A biogeographical study of Pereskia aculeata in the Greater St Lucia area (RCB, Distinction for project). Co-supervised with Dr. R. Robinson.

Mr Ross Liston (1996). Effects of habitat fragmentation on the population biology of the threatened succulent Haworthia koelmaniorum (RCB, Distinction for project). Employed by SRK. 1 paper.

Ms. Megan Wilson (1996). Autecology of the invasive alien plant, Chromolaena odorata, in the greater St Lucia Wetland Park (RCB).
Ms. Michele F. Pfab. (1997). Conservation biology of rare Northern Province plant species (RCB, distinction). Employed by Gauteng Nature Conservation (DACEL) ? Doing a fantastic conservation job! 4 papers.

Mr. Edward Netshithothole (1998). Woody plant diversity at the Wits Rural Facility. Employed by SA National Parks. Co-supervised with Dr. R. Robinson.

Ms. Babalwa A. Mbalo. Post-fire effects on germination of selected savanna woody plants. MSc (Feb. 97 - June 99). Distinction. Awarded a 2 year Mellon scholarship. 1 paper published. Employed by SRK as an environmental consultant. Awarded the South African Association for the Advancement of Science?s S2A3 medal for the best MSc in the Science Faculty (2000).

Ms. Jenny Botha. Perceptions of species availability and values of medicinal plants traded in areas adjacent to the Kruger National Park. MSc (Feb. 97 ? Nov 2001; part time). 6 papers, 2 submitted. Co-supervised with Prof. C. Shackleton.

Mr. Delali Dovie (Ghana). Secondary utilization, valuation and rural livelihoods in the woodlands of the Bushbuckridge Lowveld, South Africa. MSc (RCB) (Feb. 99 ? Mar 01). Invited to attended the inaugural Student Science Conference on ?Conservation Biology? at Cambridge University (UK), March 2000 (organised for MSc and PhD students)(Distinction). 4 papers 2 conference papers. Co-supervised with Prof. C. Shackleton.

Ms. Angela Freeman. Mycorrhizal status of gold slimes dams and surrounding areas. MSc (RCB) (Feb. 2000 ? Mar. 2001). Working for a UK Town Council as the Environmental Officer. Co-supervised with Dr. C. Straker.

Ms Susan Bradley. Population dynamics and regeneration of the African savanna trees, Acacia nilotica and A. tortilis. MSc (RCB) (Feb. 2000 ? Mar. 2001). Working for Strategic Environmental Focus as an Environmental Consultant from 4th April 2001.

Ms. Katharine van der Velde. Population dynamics and regeneration of Ficus sycamorus along the Sabie River, KNP, in response to the 2000 floods. MSc (RCB) (Feb. 2000 ? June 2001, graduated in 2002). Changed to part-time in Nov. 2000 because of employment (Environmental Consultant) for Jones & Wagener, Consulting Civil Engineers. Distinction. Co-supervised with Prof. K. Rogers.

Mr. Bradley Wilson. Population dynamics and regeneration ecology of the African savanna tree, Burkea africana. MSc (Feb. 2000 ? Dec. 2002). Distinction, 1 paper.

Mr. Marc Leroy. MSc (Jan. 2001-Mar 2003). Recovery of alien plants and bio-control agents on the Sabie River, Kruger National Park, after the 2000 floods. Graduated Nov 2003. Co-supervised with Prof. K. Rogers. Nature Conservation Scientist: conservation biology and botany. Limpopo Province, Directorate Environment.

Ms. Louisa O. Nakanuku. MSc (Feb 2002-Mar 2003). Assessing the use of terrestrial environmental monitoring programmes using biodiversity indicators for the Namibian State of the Environment Reporting. Working for the Namibian Government on the State of the Environment Report. Graduated Nov 2003. Co-supervised with Dr. J. Ziegler.

Mr. Richard D. Garner. Changes in plant diversity after clearing of alien plants along riverine corridors in Mpumalanga, South Africa. MSc (Jan. 96; part time since 1998). Employed as Environmental Officer at AMCOAL. 2 papers. Grassland Society of S.A. Research Award, 1998.

Mr. Sean O?Regan. Long-term monitoring of veld burning in the Kruger National Park in relation to fire frequency, season and landscape position. MSc (Jan. 96, part time since 1998). Working for Africam. 1 paper.

Mr. Andrew Parker. An Ecological study of the vegetation structure and composition and large mammalian fauna of Welgevonden Nature Reserve in the Waterberg Region, Northern Province. MSc (Feb. 97; part time 99). Employed by SANP, but formally Africam. 1 paper. Is c Greenberg Prize, 1997; Grassland Society of S.A. Research Award, 2000.

Ms. Dalit Marom. MSc (Jan 2003). Conservation biology of six Delosperma spp. in Gauteng Province. Co-supervised with Ms. M. Pfab.

Ms. Caroline Angus. MSc (Jan 2003). The use of AFLP analysis to determine genetics differences of populations of a plant species on and off slimes dams. Co-supervised with Prof. T. McLellan

Ms. Renee van rde. MSc (Jan 2004). Assessing the vegetating of slopes of gold slimes dams.

Ms. Margaret Beater. MSc (Apil 2004). Working for Water Project: Ecosystem Repair.

Mr. Gabriel T Ngorima (Zimbabwean) MSc (RCB) (Jan 2005). Towards sustainable use of Marula (Sclerocarya birrea) in the Savannah woodlands of Zvishavane District, Zimbabwe. Completed Mar 06, graduated Nov 2006.

Ms. Margaret Beater. MSc (Mar 2004). Impacts of invasive alien plant clearing on riparian vegetation recovery along riverine corridors in Mpumalanga, South Africa. Completed June 06, graduated Nov 2006.

Ms. Dalit Marom. MSc (Jan 2003). Conservation biology of six Delosperma spp. in Gauteng Province. Co-supervised with Ms. M. Pfab. Completed August 2006, graduated April 07.

Mr. Luke Schultz (Jan 06). Biology of the emergent alien invasive weed, Hydrilla. Co-supervisor Dr. Julie Coetzee. Submitted July 2007.

PhD

Dr. Emmanuel J. Luoga (Tanzania). The effects of human disturbances on diversity and dynamics of Eastern Tanzania miombo woodlands. PhD (Nov. 96 ? Nov 00). Leave of absence from lecturing post at Morogoro. 6 papers, 1 conference paper, 2 submitted. Promoted to Senior Lecturer, and now Ass Prof? Co-supervised with Prof. K. Balkwill.

Dr. Marc Stalmans. Vegetation, fire and herbivore interrelationships in the Songimvelo Game Reserve: a landscape ecological approach towards analyzing pattern and change. PhD (part time). Worked for Mpumalanga Parks Board, now a freelance consultant. Took over supervision in 1999. 4 papers. Grassland Society of S.A. Research Award, 2001. Completion: Sept. 2002. Co-supervised with Prof. K. Balkwill.

Dr. Taelo Letsela (Lesotho). Sustainable utilization of the resources within the Tsehlanyane ? Bokong Biosphere Reserve in Lesotho. PhD (Feb. 99- March 2004). Leave of absence, National University of Lesotho (Res. Fell., Inst. S African Studies). 3 papers, 2 submitted. Awarded a 3-year Mellon Scholarship. Co-supervised with Prof. K. Balkwill.

Dr. Kirsten Neke. Regeneration Ecology of savanna woodlands in relation to human impacts. PhD (Feb. 2000). Completion: 2005. 1 conference 1 paper. Co-supervised with Prof. N. Owen-Smith. Completed April 2005.

Dr. Jenny Botha. PhD (Mar 2002). The viability of conservation and social forestry outreach nurseries. Completed March 06, graduated Nov 06. Co-supervised with Prof. J. Cock (Sociology, Wits).

Dr. Delali Dovie (Ghana). PhD (April 2001). Relationship between woody biodiversity and use of non-tumber forest products in the savanna biome of South Africa. Completion April 06, graduated Nov 2006. Co-supervised with Prof. C. Shackleton.

Dr. Vivienne Williams. Design of a risk assessment model to determine the impacts of the herbal trade on the Witwatersrand on resources of indigenous plant species. MSc (Jan. 94, upgraded to PhD Feb. 97; part-time since 1999). Co-supervised with Prof. K. Balkwill.

Mr. Edward N. Mwavu. PhD (May 2002). Community assessment, environmental gradients and use of wood products from Budongo Tropical Rain Forest, Uganda.


Research Interests

Ed was a founder member of the Southern African Institute of Ecologists and Environmental Scientists and serves on various conservation fora. Ed?s current research interests include (a) the population dynamics and regeneration of savanna trees, including fire and browse utilisation by large herbivores in savanna ecosystems, (b) conservation biology of rare and endangered plants, (c) restoration of degraded ecosystems, (d) plant ecophysiology and stress ecology, (d) sustainable renewable resource use in relation to human livelihoods, (e) ecology and ecophysiology of sclerophyllous shrubs in mediterranean ecosystems, (f) the biology of problem alien plants and (g) the vegetation of gold slimes dams

Ecology and Conservation of Savannas and Grasslands

Ed Witkowski is the Head of the Restoration and Conservation Biology Research Group, and professor of Plant Ecology.

Publications

Ecological Economics/Economic Botany

  • Dovie, DBK, Shackleton, CM & Witkowski, ETF. (2002). Direct-use values of woodland resources consumed and traded in a South African village. The International Journal of Sustainable Development and World Ecology 9, 269-283.
  • Letsela, T. Witkowski, E.T.F. & Balkwill, K. (2002). Direct use values of communal resources in Bokong and Tsehlanyane in Lesotho: Whither the commons? The International Journal of Sustainable Development and World Ecology 9, 351-368.
  • Dovie, DBK, Witkowski, ETF & Shackleton, CM. (2003). Direct-use value of smallholder crop production in a semi-arid rural South African village. Agricultural Systems 76, 337-357.
  • Williams, V.L., Balkwill, K. & Witkowski, E.T.F. (1997). Muthi traders on the Witwatersrand, South Africa - an urban mosaic. South African Journal of Botany 63, 378-381.
  • Dzerefos, C.M., Witkowski, E.T.F. & Shackleton, C.M. (1998). Seedling establishment, post-harvesting recovery and growth rates of the woodrose-producing mistletoe, Erianthemum dregei. South African Journal of Botany 64, 303-307.
  • Dzerefos, C.M., Shackleton, C.M. & Witkowski, E.T.F. (1999). Sustainable utilization of woodrose-producing mistletoes (Loranthaceae) in South Africa. Economic Botany 53, 439-447.
  • Botha, J. (MSc student) (1998). Developing an understanding of problems being experienced by traditional healers living on the western border of the Kruger National Park: foundations for an integrated conservation and development programme. Development southern Africa 15, 621-634.
  • Luoga, E.J., Witkowski, E.T.F. & Balkwill, K. (2000). Subsistence use of wood products and shifting cultivation within a miombo woodland of eastern Tanzania, with some notes on commercial uses. South African Journal of Botany 66, 72-85.
  • Williams, V.L., Balkwill, K. & Witkowski, E.T.F. (2000). Unravelling the commercial market for medicinal plants and plant parts on the Witwatersrand. Economic Botany 54, 310-327.
  • Luoga, E.J., Witkowski, E.T.F. & Balkwill, K. (2000). Differential utilization and ethnobotany of trees in Kitulanghalo Forest Reserve and surrounding communal lands, eastern Tanzania. Economic Botany 54, 328-343.
  • Grundy, I., Turpie, J.K., Jagger, P., Witkowski, E.T.F., Guambe, I., Semwayo, D. & Solomon, A. (2000). Implications of co-management for benefits from natural resources for rural households in north-western Zimbabwe. Ecological Economics 33, 369-381.
  • Luoga, E.J., Witkowski, E.T.F. & Balkwill, K. (2000). Economics of charcoal production in miombo woodlands of eastern Tanzania: some hidden costs associated with commercialization of the resources. Ecological Economics 35, 243-257.
  • Dzerefos, C.M. & Witkowski, E.T.F. (2001). Density and potential utilization of medicinal grassland plants from Abe Bailey Nature Reserve, South Africa. Biodiversity and Conservation 10, 1875-1896.
  • Williams, V.L., Balkwill, K. & Witkowski, E.T.F. (2001). Checklist of plants used in the muthi trade on the Witwatersrand, South Africa. Bothalia 31, 71-98.
  • Botha, J., Witkowski, ETF & Shackleton, CM. (2001). An inventory of medicinal plants traded on the western boundary of the Kruger National Park, South Africa. Koedoe 44, 7-46.
  • Luoga, E.J., Witkowski, E.T.F. & Balkwill, K. (2002). Harvested and standing wood stocks in protected and communal miombo woodlands of eastern Tanzania. Forest Ecology and Management 164, 15-30.
  • Botha, J., Witkowski, ETF & Shackleton, CM. (2002). A comparison of anthropogenic and elephant disturbance on Acacia xanthoploea (fever tree) populations in the lowveld, South Africa. Koedoe 45, 9-18.
  • Letsela, T. Witkowski, E.T.F. & Balkwill, K. (2003). Plant resources used for subsistence in Tsehlanyane and Bokong in Lesotho. Economic Botany 57, 619-639.
  • Luoga, E.J., Witkowski, E.T.F. & Balkwill, K. (2004). Regeneration by coppicing (resprouting) of miombo (African savanna) trees in relation to land use. Forest Ecology and Management 189, 23 ? 35.
  • Botha, J., Witkowski, ETF & Shackleton, CM. (2004). Market profiles and trade in medicinal plants in the lowveld, South Africa. Environmental Conservation, 31(1)38-46.
  • Botha, J, Witkowski ETF & Shackleton, CM. 2004. The impact of commercial harvesting on Warburgia salutaris (?pepper-bark tree?) in Mpumalanga, South Africa. Biodiversity & Conservation, 13(9): 1675-1698
  • Dovie, DBK., Witkowski, ETF & Shackleton, C.M. (2004). The fuelwood crisis in southern Africa ? relating fuelwood use to livelihoods in a rural village. GeoJournal, 60 (2): 123-133
  • Luoga, E.J., Witkowski, E.T.F. & Balkwill, K. Land cover and use changes in relation to the institutional framework and tenure of land and resources in eastern Tanzania miombo woodlands. Environment, Development and Sustainability.
  • Dovie, DBK, Witkowski, ETF & Shackleton, CM. Monetary valuation of livelihoods for understanding the composition and complexity of rural households. Agriculture and Human Values.
  • Botha, J. Witkowski, ETF, Shackleton, CM & Fairbanks, DHK. (2004). Socio-economic differentiation in the trade of wildlife species for traditional medicines in the Lowveld, South Africa: implications for resource management. The International Journal of Sustainable Development and World Ecology.
  • Dovie, DBK, Shackleton, CM. & Witkowski, ETF. The value of goods and services attributed to livestock in a rural village, South Africa. Land Use Policy.
  • Williams, V.L., Witkowski, E.T.F. & Balkwill, K. Application of diversity indices to appraise plant availability in the Traditional Medicinal markets of Johannesburg, South Africa. Biodiversity & Conservation.
  • Botha, J., Witkowski, ETF & Cock, J. in press. A review of nurseries as a conservation or social forestry outreach tool. The International Journal of Sustainable Development and World Ecology.
  • Botha, J., Witkowski, ETF & Shackleton, CM. in press. Harvesting impacts on two commonly used medicinal tree species (Catha edulis & Rapanea melanophloeos) under different land management regimes in Mpumalanga, South Africa. Koedoe.

POPULATION DYNAMICS AND REGENERATION OF SAVANNA AND GRASSLAND PLANTS

  • Wilson, B.G. & Witkowski, E.T.F. (2003). Seed banks, bark thickness, and changes in age and size structure (1978 ? 1999) of the African savanna tree, Burkea africana. Plant Ecology 167, 151-162.
  • Dzerefos, C.M., Witkowski, E.T.F. & Shackleton, C.M. (2003). Host preference and density of woodrose-forming mistletoes (Loranthaceae) on savanna vegetation, South Africa. Plant Ecology 167, 163-177.
  • Witkowski, E.T.F. & O Connor, T.G. (1996). Topo-edaphic, floristic and physiognomic gradients of woody plants in a semi-arid African savanna woodland. Vegetatio 124, 9-23.
  • Dzerefos, C.M. & Witkowski, E.T.F. (1997). Development and anatomy of the attachment structure of woodrose-producing mistletoes. South African Journal of Botany 63, 416-420.
  • Pfab, M. & Witkowski, E.T.F. (1997). Use of Geographic Information Systems to search for additional populations and relocation sites for the endangered Northern Province endemic, Euphorbia clivicola. South African Journal of Botany 63, 351-355. IF=0.394, Citations=1
  • Mbalo, B.A. & Witkowski, E.T.F. (1997). Tolerance to soil temperatures experienced during and after the passage of fire in seeds of Acacia karroo, A. tortilis and Chromolaena odorata. South African Journal of Botany 63, 421-425.
  • Witkowski, E.T.F. & Liston, R.J. (1997). Population structure, habitat profile and regeneration of Haworthia koelmaniorum, a vulnerable dwarf succulent, endemic to Mpumalanga, South Africa. South African Journal of Botany 63, 363-370.
  • Garner, R.D. & Witkowski, E.T.F. (1997). Variations in seed size and shape in relation to depth of burial in the soil and pre-dispersal predation in Acacia nilotica, A. tortilis and Dichrostachys cinerea. South African Journal of Botany 63, 371-377. (Awarded the Grassland Society of Southern Africa ?Student Rangelands Research Award?, 1998).
  • Wilson, T. & Witkowski, E.T.F. (1998). Water requirements for germination and early seedling establishment in four African savanna woody plant species. Journal of Arid Environments 38, 541-550.
  • Parker, A. & Witkowski, E.T.F. (1999) Long-term impacts of abundant perennial water provision for game on herbaceous vegetation in a semi-arid African savanna woodland. Journal of Arid Environments 41, 309-321. (Awarded the Grassland Society of Southern Africa ?Student Rangelands Research Award?, 2000).
  • Pfab, M. & Witkowski, E.T.F. (1999). Fire survival of the Critically Endangered succulent, Euphorbia clivicola R.A. Dyer - fire-avoider or fire-tolerant. African Journal of Ecology 37, 249-257.
  • Pfab, M. & Witkowski, E.T.F. (1999). Contrasting effects of herbivory on plant size and reproductive performance in two populations of the Critically Endangered plant, Euphorbia clivicola. Plant Ecology 145, 317-325.
  • Van Wilgen, B.W., Biggs, H.C., O?Regan S.P. (MSc student) and Mare, N. (2000). A fire history of the savanna ecosystems in the Kruger National Park, South Africa, between 1941 and 1996. South African Journal of Science 96, 167-178.
  • Knowles, L. & Witkowski, E.T.F. (2000). Conservation biology of the succulent shrub, Euphorbia barnardii, a serpentine endemic of the Northern Province, South Africa. Austral Ecology 25, 241-252.
  • Witkowski, E.T.F. & Garner, R.D. (2000). Spatial distribution of soil seed banks of three African savanna woody species at contrasting sites. Plant Ecology 149, 91-106.
  • Pfab, M.F. & Witkowski, E.T.F. (2000). A simple population viability analysis of the Critically Endangered Euphorbia clivicola R.A. Dyer under four management scenarios. Biological Conservation 96, 263-270.
  • Witkowski, E.T.F. & Wilson, M. (2001). Changes in density, biomass, seed banks and seed production of the alien invasive plant Chromolaena odorata, along a 15 year chronosequence. Plant Ecology 152, 13-27.
  • Stalmans, M.E. Balkwill, K. Witkowski, E.T.F. & Rogers, K.H. (2001). A landscape ecological approach to address scaling problems in conservation management and monitoring. Environmental Management 28, 389-401.
  • Lamont, B.B., Marsula, R., Enright, N.J. & Witkowski, E.T.F. (2001). Conservation of an exploited wildflower: modelling growing condition, picking intensity and fire interval effects. Biological Conservation 99, 157-168.
  • Witkowski, E.T.F., Dahlmann, L.A. & Boycott, R.C. (2001). Conservation biology of Kniphofia umbrina, a critically endangered Swaziland serpentine endemic. South African Journal of Science. 97, 609-616.
  • Stalmans, M.E., Witkowski, ETF & Balkwill, K. (2002). Evaluating the ecological relevance of habitat maps for wild herbivores. Journal of Range Management 55, 127-134. (Awarded the Grassland Society of Southern Africa ?Student Rangelands Research Award?, 2001).
  • Stalmans, M.E., Balkwill, K. & Witkowski, ETF. Habitats and trees of the Songimvelo Game Reserve, Mpumalanga. Trees in South Africa, 50.

FYNBOS BIOME / AUSTRALIAN HEATHLANDS ECOLOGY / ECOPHYSIOLOGY

  • Witkowski, E.T.F. & Mitchell, D.T. (1987). Variations in soil phosphorus in the fynbos biome, South Africa. Journal of Ecology 75, 1159-1171.
  • Esler, K.J., Cowling, R.M., Witkowski, E.T.F. & Mustart, P.J. (1989). Reproductive traits and nitrogen and phosphorus accumulation during the development of fruits of Protea compacta R. Br. (Calcifuge) and P. obtusifolia Buek. ex Meisn. (Calcicole). The New Phytologist 112, 109-115. Witkowski, E.T.F. (1989). Effects of nutrient additions on litter production and nutrient return in a nutrient-poor Cape fynbos ecosystem. Plant & Soil 117, 227-235.
  • Witkowski, E.T.F. (1989). Effects of nutrient additions on the distribution of dry mass, nitrogen and phosphorus in seedlings of Protea repens (L.) L. (Proteaceae). The New Phytologist 112,481-487.
  • Witkowski, E.T.F. (1989). Response to nutrient additons by the plant growth forms of sand-plain lowland fynbos, South Africa. Vegetatio 79, 89-97.
  • Witkowski, E.T.F. & Mitchell, D.T. (1989). The effects of nutrient additions on above-ground phytomass and its phosphorus and nitrogen contents of sand-plain lowland fynbos. South African Journal of Botany 55, 243-249.
  • Witkowski, E.T.F. (1990). Effects of nutrient additions on the allocation of dry mass, phosphorus and nitrogen in the Cape fynbos plant Thamnochortus punctatus Pill. (Restionaceae). South African Journal of Ecology 1, 38-44.
  • Witkowski, E.T.F. (1990). Nutrient limitation of inflorescence and seed production in Leucospermum parile (Proteaceae) in the Cape fynbos. Journal of Applied Ecology 27, 148-158.
  • Witkowski, E.T.F., Mitchell, D.T. & Stock, W.D. (1990). Response of a Cape fynbos ecosystem to nutrient additions: Nutrient dynamics in fertilized soils. Acta Oecologica 11, 165-179.
  • Witkowski, E.T.F., Mitchell, D.T. & Stock, W.D. (1990). Response of a Cape fynbos ecosystem to nutrient additions: Shoot growth and nutrient contents of a proteoid (Leucospermum parile) and an ericoid (Phylica cephalantha) evergreen shrub. Acta Oecologica 11, 311-326.
  • Witkowski, E.T.F. (1991). Growth and competition between seedlings of Protea repens (L.) L. and the alien invasive, Acacia saligna (Labill.) Wendl., in relation to nutrient availability. Functional Ecology 5, 101-110.
  • Witkowski, E.T.F. (1991). Effects of invasive alien acacias on nutrient cycling in the coastal lowlands of the Cape fynbos. Journal of Applied Ecology 28, 1-15. Witkowski, E.T.F. & Lamont, B.B. (1991). Leaf specific mass confounds density and thickness. Oecologia, 88 486-493.
  • Witkowski, E.T.F., Lamont, B.B. & Connell, S.J. (1991). Seed bank dynamics of three co-occurring banksias in south coastal Western Australia: Plant age, cockatoos, senescence and interfire establishment. Australian Journal of Botany 39, 385-397.
  • Witkowski, E.T.F., Lamont, B.B., Walton, C. & Radford, S. (1992). Leaf demography, sclerophylly and ecophysiology of two banksias with contrasting leaf life spans. Australian Journal of Botany 40, 849-62.
  • Lamont, B.B., Witkowski, E.T.F., & Enright, N.J. (1993). Post-fire litter microsites: safe for seeds, unsafe for seedlings. Ecology 74, 501-512.
  • Lamont, B.B. Klinkhamer, P.G.L. & Witkowski, E.T.F. (1993). Population fragmentation may reduce fertility to zero in Banksia goodii - a demonstration of the Allee effect. Oecologia 94, 446-450
  • Cowling, R.M. & Witkowski, E.T.F. (1994). Convergence and non-convergence of plant traits in climatically and edaphically matched sites in mediterranean Australia and South Africa. Australian Journal of Ecology 19, 220-232.
  • Lamont, B.B., Rees, R.G., Witkowski, E.T.F. & Whitten, V.A. (1994). Comparative size, fecundity and ecophysiology of roadside plants of Banksia hookeriana. Journal of Applied Ecology 31, 137-144.
  • Lamont, B.B., Whitten, V.A., Witkowski, E.T.F., Rees, R.G. & Enright, N.J. (1994). Regional and local (road verge) effects on size and fecundity in Banksia menziesii. Australian Journal of Ecology 19, 197-205.
  • Witkowski, E.T.F. (1994). Growth of seedlings of the invasives, Acacia saligna and A. cyclops, in relation to soil phosphorus. Australian Journal of Ecology 19, 290-296.
  • Witkowski, E.T.F., Lamont, B.B. & Obbens, F.J. (1994). Commercial picking of Banksia hookeriana in the wild reduces subsequent shoot, flower and seed production. Journal of Applied Ecology 31, 508-520.
  • Cowling, R.M., Witkowski, E.T.F., Milewski, A.V. & Newbey, K.R. (1994). Taxonomic, edaphic and biological aspects of plant endemism on matched sites in mediterranean Australia and South Africa. Journal of Biogeography 21, 651-664.
  • Lamont, B.B. & Witkowski, E.T.F. (1995). A test for lottery recruitment among four Banksia species based on their demography and biological attributes. Oecologia 101, 299-308.
  • Lamont, B.B., Wills, R.T. & Witkowski, E.T.F. (1995). Threats to the conservation of southwestern Australian Proteaceae. Acta Horticulturae 387, 9-18.
  • Witkowski, E.T.F. & Lamont, B.B. (1995). Commercial picking of Banksia hookeriana from natural populations adversely affects shoot, flower and seed production and plant nutrient status. Acta Horticulturae 387, 23-32.
  • Witkowski, E.T.F. & Lamont, B.B. (1996). Nutrient losses from commercial picking and cockatoo removal of Banksia hookeriana blooms at the organ, plant and site levels. Journal of Applied Ecology 33, 131-140.
  • Witkowski, E.T.F. & Lamont, B.B. (1996). Disproportionate allocation of mineral nutrients and carbon between vegetative and reproductive structures in Banksia hookeriana. Oecologia 105, 38-42.
  • Witkowski, E.T.F. & Lamont, B.B. (1997). Does the rare Banksia goodii have inferior vegetative, reproductive or ecological attributes compared with its widespread co-occurring relative B. gardneri? Journal of Biogeography 24, 469-482.
  • Dreschler, M, Lamont, B.B., Burgman, M.A, Akcakaya, H.R., Witkowski, E.T.F. & Supriyadif. (1999). Modelling the persistence of an apparently immortal Banksia species after fire and land clearing. Biological Conservation 88, 249-259.
  • Lamont, B.B., Groom, P.K., Richards, M.B. & Witkowski, E.T.F. (1999). Recovery of Banksia and Hakea communities after fire in mediterranean Australia ? the role of species diversity and functional attributes. Diversity and Distributions 5, 15-26.

RESTORATION ECOLOGY / REHABILITATION

  • Witkowski, E.T.F., Weiersbye, I.M., Przybylowicz, W. & Mesjasz-Przybylowicz, J. (1997). Nuclear microprobe studies of elemental distribution in dormant seeds of Burkea africana. Nuclear Instruments and Methods in Physics Research B 130, 381-387.
  • Weiersbye, IM, Witkowski, ETF & Reichardt, M. Plants growing on gold and uranium slimes dams of South Africa?s deep-level mines. Bothalia.

Papers submitted, in review

  • Botha, J., Witkowski, ETF & Shackleton, CM. Factors influencing prices of medicinal plants traded in the Lowveld, South Africa. Ecological Economics.
  • Luoga, E.J., Witkowski, E.T.F., Balkwill, K. & Williams, VL. The impact of human disturbances on arborescent species richness and diversity in miombo woodlands of Kitulanghalo Forest Reserve and surrounding general lands of eastern Tanzania. Plant Ecology.
  • Luoga, E.J., Witkowski, E.T.F., Balkwill, K. & Malimbwi, RE. Population dynamics of three highly utilized miombo (African savanna) tree species: the role of land-use, plant size and silvicultural prescriptions. Forest Ecology & Management.
  • Stalmans, M.E., Witkowski, ETF & Balkwill, K. Landscape management using a laissez-faire approach to fire. Landscape Ecology.
  • Letsela, T. Witkowski, E.T.F. & Balkwill, K. Size class distribution, use and regeneration of Leucosidea sericea Eckl. & Zeyh. (Rosaceae) between protected and communal areas in Tsehlanyane, Lesotho. Forest Ecology & Management.
  • Williams, V.L., Witkowski, E.T.F. & Balkwill, K. The use of species accumulation functions to evaluate sampling effort and predict species richness for ethnomedicinal samples- a case study from South Africa. Biodiversity & Conservation.
  • Whitfield, BP, Straker, CJ & Witkowski, ETF. Mycotrophic dependency of eight plant species naturally occurring on gold slimes dams in South Africa. Mycorrhiza.
  • Williams, V.L., Witkowski, E.T.F. & Balkwill, K. Relationship between bark thickness and diameter at breast height for six tree species with medicinal bark in South Africa. Forest Ecology & Management.
  • Williams, V.L., Balkwill, K. & Witkowski, E.T.F. Determining bark surface area on the fluted stems of the medicinal tree Balanites maughamii. South African Journal of Botany.
  • Whitfield, BP, Straker, CJ & Witkowski, ETF. AMF specificity of selected plant species growningold mine tailings. Journal of Applied Soil Ecology.
  • Whitfield, BP, Straker, CJ & Witkowski, ETF. Toxic elemental allocation patterns within plants grown in gold mine tailings under AMF conditions (ICP analysis).
  • Straker, CJ, Weiersbye IM & Witkowski, ETF. Arbuscular mycorrhiza (AM) status of gold and uranium tailings and surrounding soils of South Africa s deep level gold mines. I. Root colonization and spore levels. Journal of Applied Soil Ecology.
  • Freeman, AJ, Straker, CJ & Witkowski, ETF. Arbuscular mycorrhiza (AM) status of gold and uranium tailings and surrounding soils of South Africa s deep level gold mines. II. Infectivity. Environmental Microbiology / Environmental Pollution.
  • Williams, VL., Witkowski, ETF and Balkwill, K. Height, branch-free bole length and bark thickness for six tree species used medicinally in South Africa. Koedoe

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