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Coetsee C, Botha J, Case MF, Manganyi A, Siebert F. The hard lives of trees in African savanna—Even without elephants. AUSTRAL ECOL 2023. [DOI: 10.1111/aec.13283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Corli Coetsee
- Scientific Services South African National Parks, Savanna Node, Kruger National Park Skukuza South Africa
- School of Natural Resource Management Nelson Mandela University George South Africa
| | - Judith Botha
- Scientific Services South African National Parks, Savanna Node, Kruger National Park Skukuza South Africa
| | - Madelon F. Case
- University of Oregon Eugene Oregon USA
- U.S. Geological Survey Forest and Rangeland Ecosystem Science Center Corvallis Oregon USA
| | - Adolf Manganyi
- Scientific Services South African National Parks, Savanna Node, Kruger National Park Skukuza South Africa
| | - Frances Siebert
- Unit for Environmental Sciences and Management North‐West University Potchefstroom South Africa
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Mashau ME, Kgatla TE, Makhado MV, Mikasi MS, Ramashia SE. Nutritional composition, polyphenolic compounds and biological activities of marula fruit ( Sclerocarya birrea) with its potential food applications: a review. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2022. [DOI: 10.1080/10942912.2022.2064491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Mpho Edward Mashau
- Department of Food Science and Technology, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou, South Africa
| | - Tsietsie Ephraim Kgatla
- Department of Food Science and Technology, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou, South Africa
| | - Mashudu Viginia Makhado
- Department of Plant and Soil Sciences, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou, South Africa
| | - Masiza Samuel Mikasi
- Department of Animal Science, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou, South Africa
| | - Shonisani Eugenia Ramashia
- Department of Food Science and Technology, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou, South Africa
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Zhou Y, Tingley MW, Case MF, Coetsee C, Kiker GA, Scholtz R, Venter FJ, Staver AC. Woody encroachment happens via intensification, not extensification, of species ranges in an African savanna. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02437. [PMID: 34374155 DOI: 10.1002/eap.2437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/06/2021] [Indexed: 06/13/2023]
Abstract
Widespread woody encroachment is a prominent concern for savanna systems as it is often accompanied by losses in productivity and biodiversity. Extensive ecosystem-level work has advanced our understanding of its causes and consequences. However, there is still debate over whether local management can override regional and global drivers of woody encroachment, and it remains largely unknown how encroachment influences woody community assemblages. Here, we examined species-level changes in woody plant distributions and size structure from the late 1980s to the late 2000s based on spatially intensive ground-based surveys across Kruger National Park, South Africa. This study region spans broad gradients in rainfall, soil texture, fire frequency, elephant density, and other topographic variables. Species-level changes in frequency of occurrence and size class proportion reflected widespread woody encroachment primarily by Dichrostachys cinerea and Combretum apiculatum, and a loss of large trees mostly of Sclerocarya birrea and Acacia nigrescens. Environmental variables determining woody species distributions across Kruger varied among species but did not change substantially between two sampling times, indicating that woody encroachers were thickening within their existing ranges. Overall, more areas across Kruger were found to have an increased number of common woody species through time, which indicated an increase in stem density. These areas were generally associated with decreasing fire frequency and rainfall but increasing elephant density. Our results suggest that woody encroachment is a widespread but highly variable trend across landscapes in Kruger National Park and potentially reflects an erosion of local heterogeneity in woody community assemblages. Many savanna managers, including in Kruger, aim to manage for heterogeneity in order to promote biodiversity, where homogenization of vegetation structure counters this specific goal. Increasing fire frequency has some potential as a local intervention. However, many common species increased in commonness even under near-constant disturbance conditions, which likely limits the potential for managing woody encroachment in the face of drivers beyond the scope of local control. Regular field sampling coupled with targeted fire management will enable more accurate monitoring of the rate of encroachment intensification.
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Affiliation(s)
- Yong Zhou
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, Connecticut, 06511, USA
- Yale Institute for Biospheric Studies, Yale University, New Haven, Connecticut, 06511, USA
| | - Morgan W Tingley
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095, USA
| | - Madelon F Case
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, Connecticut, 06511, USA
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, 97403, USA
| | - Corli Coetsee
- Scientific Services, Kruger National Park, Private Bag X402, Skukuza, 1350, South Africa
- School of Natural Resource Management, Nelson Mandela University, George Campus, George, 6529, South Africa
| | - Gregory A Kiker
- Department of Agricultural and Biological Engineering, University of Florida, Gainesville, Florida, 32611, USA
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Scottsville, 3209, South Africa
| | - Rheinhardt Scholtz
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Freek J Venter
- Balule Nature Reserve, Hoedspruit, Limpopo Province, South Africa
| | - A Carla Staver
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, Connecticut, 06511, USA
- Yale Institute for Biospheric Studies, Yale University, New Haven, Connecticut, 06511, USA
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Thornley R, Spencer M, Zitzer HR, Parr CL. Woody vegetation damage by the African elephant during severe drought at Pongola Game Reserve, South Africa. Afr J Ecol 2020. [DOI: 10.1111/aje.12736] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Reece Thornley
- Department of Earth, Ocean, and Ecological Sciences School of Environmental Sciences University of Liverpool Liverpool UK
| | - Matthew Spencer
- Department of Earth, Ocean, and Ecological Sciences School of Environmental Sciences University of Liverpool Liverpool UK
| | | | - Catherine L. Parr
- Department of Earth, Ocean, and Ecological Sciences School of Environmental Sciences University of Liverpool Liverpool UK
- Department of Zoology & Entomology University of Pretoria Pretoria South Africa
- School of Animal, Plant & Environmental Sciences University of Witwatersrand Johannesburg South Africa
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Smit IPJ, Asner GP, Govender N, Vaughn NR, van Wilgen BW. An examination of the potential efficacy of high-intensity fires for reversing woody encroachment in savannas. J Appl Ecol 2016. [DOI: 10.1111/1365-2664.12738] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Izak P. J. Smit
- Scientific Services; South African National Parks; Private Bag X402 Skukuza 1350 South Africa
- Centre for African Ecology; School of Animal, Plant and Environmental Sciences; University of the Witwatersrand; Private Bag 3 WITS 2050 Johannesburg South Africa
| | - Gregory P. Asner
- Department of Global Ecology; Carnegie Institution for Science; 260 Panama Street Stanford CA 94305 USA
| | - Navashni Govender
- Scientific Services; South African National Parks; Private Bag X402 Skukuza 1350 South Africa
- Nelson Mandela Metropolitan University; Private Bag X6531 George 6530 South Africa
| | - Nicholas R. Vaughn
- Department of Global Ecology; Carnegie Institution for Science; 260 Panama Street Stanford CA 94305 USA
| | - Brian W. van Wilgen
- Centre for Invasion Biology; Department of Botany and Zoology; Stellenbosch University; Private Bag X1 Matieland Stellenbosch 7602 South Africa
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Levick SR, Baldeck CA, Asner GP. Demographic legacies of fire history in an African savanna. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12306] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shaun R. Levick
- Department of Biogeochemical Processes Max Planck Institute for Biogeochemistry Hans‐Knöll‐Str. 10Jena 07745 Germany
| | - Claire A. Baldeck
- Department of Global Ecology Carnegie Institution for Science 260 Panama St Stanford California 94305 USA
| | - Gregory P. Asner
- Department of Global Ecology Carnegie Institution for Science 260 Panama St Stanford California 94305 USA
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Wigley BJ, Fritz H, Coetsee C, Bond WJ. Herbivores shape woody plant communities in the Kruger National Park: Lessons from three long-term exclosures. KOEDOE: AFRICAN PROTECTED AREA CONSERVATION AND SCIENCE 2014. [DOI: 10.4102/koedoe.v56i1.1165] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
The role of grazers in determining vegetation community compositions and structuring plant communities is well recognised in grassy systems. The role of browsers in affecting savanna woody plant communities is less clear. We used three long-term exclosures in the Kruger National Park to determine the effect of browsers on species compositions and population structures of woody communities. Species assemblages, plant traits relating to browsing and soil nutrients were compared inside and outside of the exclosures. Our results showed that browsers directly impact plant species distributions, densities and population structures by actively selecting for species with traits which make them desirable to browsers. Species with high leaf nitrogen, low total phenolic content and low acid detergent lignin appeared to be favoured by herbivores and therefore tend to be rare outside of the exclosures. This study also suggested that browsers have important indirect effects on savanna functioning, as the reduction of woody cover can result in less litter of lower quality, which in turn can result in lower soil fertility. However, the magnitude of browser effects appeared to depend on inherent soil fertility and climate.Conservation implications: Browsers were shown to have significant impacts on plant communities. They have noticeable effects on local species diversity and population structure, as well as soil nutrients. These impacts are shown to be related to the underlying geology and climate. The effects of browsers on woody communities were shown to be greater in low rainfall, fertile areas compared to high rainfall, infertile soils.
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Selier SAJ, Page BR, Vanak AT, Slotow R. Sustainability of elephant hunting across international borders in southern Africa: A case study of the greater Mapungubwe Transfrontier Conservation Area. J Wildl Manage 2013. [DOI: 10.1002/jwmg.641] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sarah-Anne Jeanetta Selier
- Amarula Elephant Research Programme; School of Life Sciences; University of Kwa-Zulu-Natal; Westville Campus; Private Bag X54001; Durban 4041 South Africa
| | - Bruce R. Page
- Amarula Elephant Research Programme; School of Life Sciences; University of Kwa-Zulu-Natal; Westville Campus; Private Bag X54001; Durban 4041 South Africa
| | - Abi Tamim Vanak
- Amarula Elephant Research Programme; School of Life Sciences; University of Kwa-Zulu-Natal; Westville Campus; Private Bag X54001; Durban 4041 South Africa
- Ashoka Trust for Research in Ecology and the Environment; Bangalore India
| | - Rob Slotow
- Amarula Elephant Research Programme; School of Life Sciences; University of Kwa-Zulu-Natal; Westville Campus; Private Bag X54001; Durban 4041 South Africa
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