Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South Africa
Kigelia africana has large flowers that are vertebrate pollinated and very large fruits that are likely to be vertebrate dispersed. Our field surveys of size–class distributions of K. africana in the southern Kruger National Park (KNP) suggest a lack of recruitment. This is possibly the result of a...
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doaj-8797df8163d5404f854b4e092d41cb042020-11-25T02:41:37ZengAOSISKoedoe: African Protected Area Conservation and Science0075-64582071-07712019-04-01611e1e710.4102/koedoe.v61i1.15121195Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South AfricaJah Namah0Jeremy J. Midgley1Laurence M. Kruger2Department of Biological Sciences, University of Cape Town, Cape TownDepartment of Biological Sciences, University of Cape Town, Cape TownDepartment of Biological Sciences, University of Cape Town, Cape Town, South Africa; and, Organisation for Tropical Studies, SkukuzaKigelia africana has large flowers that are vertebrate pollinated and very large fruits that are likely to be vertebrate dispersed. Our field surveys of size–class distributions of K. africana in the southern Kruger National Park (KNP) suggest a lack of recruitment. This is possibly the result of a failure of mutualistic relationships with vertebrate dispersers and/or pollinators. Breeding system experiments indicated that K. africana is an obligate out-crosser. Despite being primarily adapted for bat pollination, in KNP that K. africana is presently mainly pollinated by a diversity of largely facultatively nectarivorous bird species. Fruit-set is high, although trees isolated by > 50 m were found to suffer depressed seed output. Our preliminary investigation of dispersal suggests that fruits are largely ignored and are thus weakly attractive to potential dispersers. Seedlings placed out in the field in KNP suffered high levels (> 50%) of mortality compared to 17.5% in control plots. This threefold difference is the result of herbivory over a 2-month period. In summary, the adult centric population structure is probably not because of pollen or seed limitation but may result from dispersal limitation or excessive herbivory.https://koedoe.co.za/index.php/koedoe/article/view/1512mutualismspollinationdispersalKigeliasausage tree |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jah Namah Jeremy J. Midgley Laurence M. Kruger |
spellingShingle |
Jah Namah Jeremy J. Midgley Laurence M. Kruger Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South Africa Koedoe: African Protected Area Conservation and Science mutualisms pollination dispersal Kigelia sausage tree |
author_facet |
Jah Namah Jeremy J. Midgley Laurence M. Kruger |
author_sort |
Jah Namah |
title |
Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South Africa |
title_short |
Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South Africa |
title_full |
Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South Africa |
title_fullStr |
Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South Africa |
title_full_unstemmed |
Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South Africa |
title_sort |
reproductive biology of the sausage tree (kigelia africana) in kruger national park, south africa |
publisher |
AOSIS |
series |
Koedoe: African Protected Area Conservation and Science |
issn |
0075-6458 2071-0771 |
publishDate |
2019-04-01 |
description |
Kigelia africana has large flowers that are vertebrate pollinated and very large fruits that are likely to be vertebrate dispersed. Our field surveys of size–class distributions of K. africana in the southern Kruger National Park (KNP) suggest a lack of recruitment. This is possibly the result of a failure of mutualistic relationships with vertebrate dispersers and/or pollinators. Breeding system experiments indicated that K. africana is an obligate out-crosser. Despite being primarily adapted for bat pollination, in KNP that K. africana is presently mainly pollinated by a diversity of largely facultatively nectarivorous bird species. Fruit-set is high, although trees isolated by > 50 m were found to suffer depressed seed output. Our preliminary investigation of dispersal suggests that fruits are largely ignored and are thus weakly attractive to potential dispersers. Seedlings placed out in the field in KNP suffered high levels (> 50%) of mortality compared to 17.5% in control plots. This threefold difference is the result of herbivory over a 2-month period. In summary, the adult centric population structure is probably not because of pollen or seed limitation but may result from dispersal limitation or excessive herbivory. |
topic |
mutualisms pollination dispersal Kigelia sausage tree |
url |
https://koedoe.co.za/index.php/koedoe/article/view/1512 |
work_keys_str_mv |
AT jahnamah reproductivebiologyofthesausagetreekigeliaafricanainkrugernationalparksouthafrica AT jeremyjmidgley reproductivebiologyofthesausagetreekigeliaafricanainkrugernationalparksouthafrica AT laurencemkruger reproductivebiologyofthesausagetreekigeliaafricanainkrugernationalparksouthafrica |
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