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Maicher V, Delabye S, Murkwe M, Doležal J, Altman J, Kobe IN, Desmist J, Fokam EB, Pyrcz T, Tropek R. Effects of disturbances by forest elephants on diversity of trees and insects in tropical rainforests on Mount Cameroon. Sci Rep 2020; 10:21618. [PMID: 33303812 PMCID: PMC7729851 DOI: 10.1038/s41598-020-78659-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/24/2020] [Indexed: 11/20/2022] Open
Abstract
Natural disturbances are essential for tropical forests biodiversity. In the Afrotropics, megaherbivores have played a key role before their recent decline. Contrastingly to savanna elephants, forest elephants’ impact on ecosystems remains poorly studied. Few decades ago, forests on Mount Cameroon were divided by lava flows, not being crossed by a local population of forest elephants until now. We assessed communities of trees, butterflies and two guilds of moths in the disturbed and undisturbed forests split by the longest lava flow. We surveyed 32 plots, recording 2025 trees of 97 species, and 7853 insects of 437 species. The disturbed forests differed in reduced tree density, height, and high canopy cover, and in increased DBH. Forest elephants’ selective browsing and foraging also decreased tree species richness and altered their composition. The elephant disturbance increased butterfly species richness and had various effects on species richness and composition of the insect groups. These changes were likely caused by disturbance-driven alterations of habitats and species composition of trees. Moreover, the abandonment of forests by elephants led to local declines of range-restricted butterflies. The recent declines of forest elephants across the Afrotropics probably caused similar changes in forest biodiversity and should be reflected by conservation actions.
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Affiliation(s)
- Vincent Maicher
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic. .,Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic. .,Nicholas School of the Environment, Duke University, 9 Circuit Dr., Durham, NC, 27710, USA.
| | - Sylvain Delabye
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic
| | - Mercy Murkwe
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,Department of Ecology, Faculty of Science, Charles University, Vinicna 7, 12844, Prague, Czech Republic
| | - Jiří Doležal
- Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic.,Institute of Botany, Czech Academy of Sciences, Dukelska 135, 37982, Trebon, Czech Republic
| | - Jan Altman
- Institute of Botany, Czech Academy of Sciences, Dukelska 135, 37982, Trebon, Czech Republic
| | - Ishmeal N Kobe
- Department of Ecology, Faculty of Science, Charles University, Vinicna 7, 12844, Prague, Czech Republic
| | - Julie Desmist
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic.,University Paris-Saclay, 15 rue Georges Clemenceau, 91400, Orsay, France
| | - Eric B Fokam
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Tomasz Pyrcz
- Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30387, Krakow, Poland.,Nature Education Centre of the Jagiellonian University, Gronostajowa 5, 30387, Krakow, Poland
| | - Robert Tropek
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic. .,Department of Ecology, Faculty of Science, Charles University, Vinicna 7, 12844, Prague, Czech Republic.
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Wilkerson ML, Roche LM, Young TP. Indirect effects of domestic and wild herbivores on butterflies in an African savanna. Ecol Evol 2013; 3:3672-82. [PMID: 24198932 PMCID: PMC3810867 DOI: 10.1002/ece3.744] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 07/16/2013] [Accepted: 07/30/2013] [Indexed: 11/30/2022] Open
Abstract
Indirect interactions driven by livestock and wild herbivores are increasingly recognized as important aspects of community dynamics in savannas and rangelands. Large ungulate herbivores can both directly and indirectly impact the reproductive structures of plants, which in turn can affect the pollinators of those plants. We examined how wild herbivores and cattle each indirectly affect the abundance of a common pollinator butterfly taxon, Colotis spp., at a set of long-term, large herbivore exclosure plots in a semiarid savanna in central Kenya. We also examined effects of herbivore exclusion on the main food plant of Colotis spp., which was also the most common flowering species in our plots: the shrub Cadaba farinosa. The study was conducted in four types of experimental plots: cattle-only, wildlife-only, cattle and wildlife (all large herbivores), and no large herbivores. Across all plots, Colotis spp. abundances were positively correlated with both Cadaba flower numbers (adult food resources) and total Cadaba canopy area (larval food resources). Structural equation modeling (SEM) revealed that floral resources drove the abundance of Colotis butterflies. Excluding browsing wildlife increased the abundances of both Cadaba flowers and Colotis butterflies. However, flower numbers and Colotis spp. abundances were greater in plots with cattle herbivory than in plots that excluded all large herbivores. Our results suggest that wild browsing herbivores can suppress pollinator species whereas well-managed cattle use may benefit important pollinators and the plants that depend on them. This study documents a novel set of ecological interactions that demonstrate how both conservation and livelihood goals can be met in a working landscape with abundant wildlife and livestock.
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Affiliation(s)
- Marit L Wilkerson
- Department of Plant Sciences, University of California Davis, California
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