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Does the presence of elephant dung create hotspots of growth for existing seedlings?

Published online by Cambridge University Press:  20 March 2019

Urs Kalbitzer
Affiliation:
Department of Anthropology, McGill University, Montreal, Quebec, Canada
Victoria McInnis
Affiliation:
Department of Natural Resource Sciences, McGill University, Ste. Anne de Bellevue, Quebec, Canada
Patrick A. Omeja
Affiliation:
Makerere University Biological Field Station, P.O. Box 967, Fort Portal, Uganda
Sarah Bortolamiol
Affiliation:
Departments of Anthropology and Geography, McGill University, Montréal, Québec, Canada UMR 7533 Laboratoire Dynamiques Sociales et Recomposition des Espaces, Paris Diderot University, Paris, France UMR 7206 Eco-Anthropologie et Ethnobiologie (MNHN/CNRS/Paris Diderot), Paris, France
Colin A. Chapman*
Affiliation:
Department of Anthropology, McGill University, Montreal, Quebec, Canada Makerere University Biological Field Station, P.O. Box 967, Fort Portal, Uganda School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi’an, China

Abstract

Megaherbivores play a central role in the evolution and functioning of ecosystems. In tropical forests elephant species are some of the few remaining megaherbivores. Through elephant foraging, nutrients that would be locked in leaves and stems, taking months or years to decay, are quickly liberated for use. In 10 experimental sites in Kibale National Park, Uganda, we set up 10 pairs of plots (4 × 4 m), each pair involved one treatment, elephant dung addition, and one control. After 1 y, we quantified growth (height and leaf number) and survival of young light-demanding (12) and shade-tolerant (19) plant species (439 stems in total). In general, the addition of elephant dung did not increase seedling growth, and it only increased the number of leaves in shade-tolerant plants with a large initial number of leaves. Researchers have speculated that the loss of elephants would shift the composition of African forests to slow-growing tree species. However, this is not supported by our finding that shows some slow-growing shade-tolerant plants grew more new leaves with additional nutrient input from elephant dung, a condition that would occur if elephant numbers increase.

Type
Research Article
Copyright
© Cambridge University Press 2019 

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References

Literature cited

Augspurger, CK (1984) Light requirements of neotropical tree seedlings: a comparative study of growth and survival. Journal of Ecology 72, 777795.CrossRefGoogle Scholar
Bates, D, Mächler, M, Bolker, B and Walker, S (2014) Fitting linear mixed-effects models using lme4. Journal of Statistical Software. https://www.jstatsoft.org/article/view/v067i01/0.Google Scholar
Blake, S (2003) The ecology of forest elephant distribution and its implications for conservation. PhD dissertation, University of Edinburgh.Google Scholar
Blake, S, Deem, SL, Mossimbo, E, Maisels, F and Walsh, P (2009) Forest elephants: tree planters of the Congo. Biotropica 41, 459468.CrossRefGoogle Scholar
Bloom, AJ, Chapin, FS and Mooney, HA (1985) Resource limitation in plants–an economic analogy. Annual Review of Ecology and Systematics 16, 363392.CrossRefGoogle Scholar
Bolker, BM, Brooks, ME, Clark, CJ, Geange, SW, Poulsen, JR, Stevens, MHH and White, J-SS (2009) Generalized linear mixed models: a practical guide for ecology and evolution. Trends in Ecology and Evolution 24, 127135.CrossRefGoogle ScholarPubMed
Breuer, T, Maisels, F and Fishlock, V (2016) The consequences of poaching and anthropogenic change for forest elephants. Conservation Biology 30, 10191026.CrossRefGoogle ScholarPubMed
Brooks, AC and Buss, IO (1962) Past and present status of the elephant in Uganda. Journal of Wildlife Management 26, 3850.CrossRefGoogle Scholar
Campos-Arceiz, A and Blake, S (2011) Megagardeners of the forest– the role of elephants in seed dispersal. Acta Oecologica 37, 542553.CrossRefGoogle Scholar
Chapman, CA, Bonnell, TR, Gogarten, JF, Lambert, JE, Omeja, PA, Twinomugisha, D, Wasserman, MD and Rothman, JM (2013) Primates as ecosystem engineers. International Journal of Primatology 34, 114.CrossRefGoogle Scholar
Chapman, CA and Lambert, JE (2000) Habitat alteration and the conservation of African primates: case study of Kibale National Park, Uganda. American Journal of Primatology 50, 169185.3.0.CO;2-P>CrossRefGoogle ScholarPubMed
Chapman, LJ, Chapman, CA and Wrangham, RW (1992) Balanites wilsoniana: elephant dependent dispersal. Journal of Tropical Ecology 8, 275283.CrossRefGoogle Scholar
Coley, P (1983) Herbivory and defensive characteristics of tree species in a lowland tropical forest. Ecological Monographs 53, 209233.CrossRefGoogle Scholar
Crain, CM and Bertness, MD (2006) Ecosystem engineering across environmental gradients: implications for conservation and management. Bioscience 56, 211218.CrossRefGoogle Scholar
Dougall, H (1963) On the chemical composition of elephant faeces. African Journal of Ecology 1, 123.CrossRefGoogle Scholar
Doughty, CE, Wolf, A and Malhi, Y (2013) The impact of large animal extinctions on nutrient fluxes in early river valley civilizations. Ecosphere 4, 117.CrossRefGoogle Scholar
Dublin, HT, Sinclair, ARE and McGlade, J (1990) Elephants and fire as causes of multiple stable states in the Serengeti Mara woodlands. Journal of Animal Ecology 59, 11471164.CrossRefGoogle Scholar
Gill, JL, Williams, JW, Jackson, ST, Lininger, KB and Robinson, GS (2009) Pleistocene megafaunal collapse, novel plant communities, and enhanced fire regimes in North America. Science 326, 11001103.CrossRefGoogle ScholarPubMed
Grubb, PJ (1977) The maintenance of species-richness in plant communities: the importance of regeneration niche. Biological Reviews 52, 107145.CrossRefGoogle Scholar
Grubb, PJ (1996) Rainforest dynamics: the need for new paradigms. In Edwards, DS (ed.), Tropical Rainforest Research– Current Issues. Dordrecht: Kluwer, pp. 215233.CrossRefGoogle Scholar
Guldemond, R and Van Aarde, R (2008) A meta-analysis of the impact of African elephants on savanna vegetation. Journal of Wildlife Management 72, 892899.CrossRefGoogle Scholar
Hamilton, AC (1991) A Field Guide to Uganda Forest Trees. Kampala: Makerere University Printery, 276 pp.Google Scholar
Hatch, D, Lovell, R, Antil, R, Jarvis, S and Owen, P (2000) Nitrogen mineralization and microbial activity in permanent pastures amended with nitrogen fertilizer or dung. Biology and Fertility of Soils 30, 288293.CrossRefGoogle Scholar
Kalbitzer, U, Mcinnis, V and Chapman, CA (2019) Primates create seedling growth hotspots through pattern of dung deposition. African Journal of Ecology. doi: 10.1111/aje.12589.CrossRefGoogle Scholar
Keigwin, M, Wabukawo, V, Wasser, SK and Chapman, CA (2016) Impacts on transboundary elephant movements between Queen Elizabeth National Park, Uganda and Park National des Virunga, Democratic Republic of Congo. Pachyderm 57, 118121.Google Scholar
King, DA (1994) Influence of light level on the growth and morphology of saplings in a Panamanian forest. American Journal of Botany 81, 948957.CrossRefGoogle Scholar
Maisels, F, Strindberg, S, Blake, S, Wittemyer, G, Hart, J, Williamson, EA, Aba’a, R, Abitsi, G, Ambahe, RD and Amsini, F (2013) Devastating decline of forest elephants in Central Africa. PLoS ONE 8, e59469.CrossRefGoogle ScholarPubMed
Majaliwa, J, Twongyirwe, R, Nyenje, R, Oluka, M, Ongom, B, Sirike, J, Mfitumukiza, D, Azanga, E, Natumanya, R and Mwerera, R (2010) The effect of land cover change on soil properties around Kibale National Park in South Western Uganda. Applied and Environmental Soil Science Article ID 185689. doi: 10.1155/2010/185689.CrossRefGoogle Scholar
Malhi, Y, Doughty, CE, Galetti, M, Smith, FA, Svenning, J-C and Terborgh, JW (2016) Megafauna and ecosystem function from the Pleistocene to the Anthropocene. Proceedings of the National Academy of Sciences USA 113, 838846.CrossRefGoogle ScholarPubMed
Marenco, RA, Goncalves, JFD and Vieira, G (2001) Leaf gas exchange and carbohydrates in tropical trees differing in successional status in two light environments in central Amazonia. Tree Physiology 21, 13111318.CrossRefGoogle ScholarPubMed
McNaughton, S, Banyikwa, F and McNaughton, M (1997) Promotion of the cycling of diet-enhancing nutrients by African grazers. Science 278, 17981800.CrossRefGoogle ScholarPubMed
Meek, B, MacKenzie, A, Donovan, T and Spencer, W (1974) The effect of large applications of manure on movement of nitrate and carbon in an irrigated desert soil. Journal of Environmental Quality 3, 253258.CrossRefGoogle Scholar
Mondol, S, Moltke, I, Hart, J, Keigwin, M, Brown, L, Stephens, M and Wasser, SK (2015) New evidence for hybrid zones of forest and savanna elephants in Central and West Africa. Molecular Ecology 24, 61346147.CrossRefGoogle ScholarPubMed
Omeja, PA, Jacob, AL, Lawes, MJ, Lwanga, JS, Rothman, JM, Tumwesigye, C and Chapman, CA (2014) Changes in elephant density affect forest composition and regeneration? Biotropica 46, 704711.CrossRefGoogle Scholar
Omeja, PA, Lawes, MJ, Corriveau, A, Valenta, K, Sarkar, D, Paim, FP and Chapman, CA (2016) Recovery of tree and mammal communities during large-scale forest regeneration in Kibale National Park, Uganda. Biotropica 48, 770779.CrossRefGoogle Scholar
Poulsen, JR, Koerner, SE, Moore, S, Medjibe, VP, Blake, S, Clark, CJ, Akou, ME, Fay, M, Meier, A and Okouyi, J (2017) Poaching empties critical Central African wilderness of forest elephants. Current Biology 27, R134R135.CrossRefGoogle ScholarPubMed
Poulsen, JR, Rosin, C, Meier, A, Mills, E, Nunez, C, Koerner, SE, Blanchard, E, Callejas, J, Moore, S and Sowers, M (2018) Ecological consequences of forest elephant declines for Afrotropical forests. Conservation Biology 32, 559567.CrossRefGoogle ScholarPubMed
R-Core-Team (2018) R: A Language and Environment for Statistical Computing. Vienna: R Foundation for Statistical Computing. http://www.R-project.org/.Google Scholar
Rees, P (1982) Gross assimilation efficiency and food passage time in the African elephant. African Journal of Ecology 20, 193198.CrossRefGoogle Scholar
Richards, PW (1996) The Tropical Rain Forest, 2nd edition. Cambridge: Cambridge University Press, 575 pp.Google Scholar
Ripple, WJ, Newsome, TM, Wolf, C, Dirzo, R, Everatt, KT, Galetti, M, Hayward, MW, Kerley, GI, Levi, T and Lindsey, PA (2015) Collapse of the world’s largest herbivores. Science Advances 1, e1400103.CrossRefGoogle ScholarPubMed
Rode, KD, Chapman, CA, Chapman, LJ and McDowell, LR (2003) Mineral resource availability and consumption by colobus in Kibale National Park, Uganda. International Journal of Primatology 24, 541573.CrossRefGoogle Scholar
Rode, KD, Chiyo, PI, Chapman, CA and McDowell, LR (2006) Nutritional ecology of elephants in Kibale National Park, Uganda, and its relationship with crop-raiding behaviour. Journal of Tropical Ecology 22, 441449.CrossRefGoogle Scholar
Ruggiero, R (1992) Seasonal forage utilization by elephants in central Africa. African Journal of Ecology 30, 137148.CrossRefGoogle Scholar
Santiago, LS, Wright, SJ, Harms, KE, Yavitt, JB, Korine, C, Garcia, MN and Turner, BL (2012) Tropical tree seedling growth responses to nitrogen, phosphorus and potassium addition. Journal of Ecology 100, 309316.CrossRefGoogle Scholar
Smart, NOE, Hatton, JC and Spence, DHN (1985) The effect of long-term exclusion of large herbivores on vegetation in Murchison Falls National Park, Uganda. Biological Conservation 33, 229245.CrossRefGoogle Scholar
Smith, RJ, Biggs, D, St John, FA, Sas-Rolfes, MT and Barrington, R (2015) Elephant conservation and corruption beyond the ivory trade. Conservation Biology 29, 953956.CrossRefGoogle ScholarPubMed
Sugihara, S, Shibata, M, Ze, ADM, Araki, S and Funakawa, S (2015) Effects of vegetation on soil microbial C, N, and P dynamics in a tropical forest and savanna of Central Africa. Applied Soil Ecology 87, 9198.CrossRefGoogle Scholar
Terborgh, J, Davenport, L, Niangadouma, R, Dimoto, E, Mouandza, J, Scholtz, O and Jaen, M (2016) Megafaunal influences on tree recruitment in African equatorial forests. Ecography 39, 180186.CrossRefGoogle Scholar
Thompson, WA, Stocker, GC and Kriedemann, PE (1988) Growth and photosynthetic response to light and nutrients of Flindersia brayleyana F Muell, a rainforest tree with broad tolerance to sun and shade. Australian Journal of Plant Physiology 15, 299315.Google Scholar
Tilman, D and Lehman, C (2001) Human-caused environmental change: impacts on plant diversity and evolution. Proceedings of the National Academy of Sciences USA 98, 54335440.CrossRefGoogle ScholarPubMed
Wright, JP and Jones, CG (2006) The concept of organisms as ecosystem engineers ten years on: progress, limitations, and challenges. Bioscience 56, 203209.CrossRefGoogle Scholar
Wright, SJ (2002) Plant diversity in tropical forests: a review of mechanisms of species coexistence. Oecologia 130, 114.CrossRefGoogle ScholarPubMed
Wright, SJ, Yavitt, JB, Wurzburger, N, Turner, BL, Tanner, EVJ, Sayer, EJ, Santiago, LS, Kaspari, M, Hedin, LO, Harms, KE, Garcia, MN and Corre, MD (2011) Potassium, phosphorus, or nitrogen limit root allocation, tree growth, or litter production in a lowland tropical forest. Ecology 92, 16161625.CrossRefGoogle ScholarPubMed
Zanne, AE and Chapman, CA (2005) Diversity of woody species in forest, treefall gaps, and edge in Kibale National Park, Uganda. Plant Ecology 178, 121139.CrossRefGoogle Scholar
Zanne, AE, Chapman, CA and Kitajima, K (2005) Evolutionary and ecological correlates of early seedling morphology in East African trees and shrubs. American Journal of Botany 92, 972978.CrossRefGoogle ScholarPubMed