Effects of anthropogenic disturbances on natural regeneration and population structure of gum arabic tree (Acacia senegal) in the woodlands of Lake Baringo ecosystem, Kenya

Published Date

Original Paper

First Online: 

30 November 2016

DOI: 10.1007/s11676-016-0349-4

Cite this article as: 

Omondi, S.F., Odee, D.W., Ongamo, G.O. et al. J. For. Res. (2016). doi:10.1007/s11676-016-0349-4

Author

• Stephen F. OmondiEmail author
• David W. Odee
• George O. Ongamo
• James I. Kanya
• Damase P. Khasa

Abstract

Despite the ecological and economic importance of Acacia senegal, little is known about the effects of anthropogenic disturbances on its natural regeneration patterns and population structure. We investigated the effects of these factors within the Lake Baringo woodland ecosystem. Data was collected from 60 plots of 20 m × 20 m systematically distributed in four A. senegal-dominated populations within the Lake Baringo woodland. Sample populations spanned a degradation gradient measured by a population disturbance index (PDI). Trees were measured for diameter at breast height (DBH) and categorized by growth stages: seedling, sapling and adult tree. Higher seedling and sapling densities were recorded in lightly than heavily disturbed populations, but only sapling density was significantly different between the two disturbance levels (P = 0.02). Lightly disturbed populations revealed a reversed J-shape size-class distribution (SCD) indicative of stable structure unlike the heavily disturbed populations. The quotient and permutation indices indicated unstable populations with episodic recruitment and mortality. Our study reveals that natural regeneration and population structure of A. senegal were affected majorly by selective harvesting and heavy browsing. Suitable management strategies to control livestock grazing and illegal tree harvesting within the woodland is required to promote conservation of the species genetic resources

References 

1. Argaw M, Teketay D, Olsson M (1999) Soil seed flora, germination and regeneration pattern of woody species in an Acacia woodland of the Rift Valley. J Arid Environ 43:411–435CrossRefGoogle Scholar
2. Baringo County Government (2014) Annual development plan 2015/16. Government printers, Nairobi, pp 54–87Google Scholar
3. Botha J, Witkowski ETF, Shackleton CM (2004) Harvesting impacts on commonly used medicinal tree species (Catha edulis and Rapanea melanophloeos) under different land management regimes in the Mpumalanga Lowveld, South Africa. Koedoe 47:1–118CrossRefGoogle Scholar
4. Brokaw NVL (1985) Gap-phase regeneration in a tropical forest. Ecology 66:682–687CrossRefGoogle Scholar
5. Bynum DZ (1999) Assessment and monitoring of anthropogenic disturbance in Lore Lindu National Park, Central Sulawesi, Indonesia. Trop Biodivers 6:43–57Google Scholar
6. Chikamai BN, Odera JA (2002) Commercial plant gums and resins in Kenya. Nairobi Executive Printers, Nairobi, pp 8–62Google Scholar
7. Cole LE, Bhagwat SA, Willis KJ (2014) Recovery and resilience of tropical forests after disturbance. Nat Commun 5:3906CrossRefPubMedPubMedCentralGoogle Scholar
8. Condit R, Sukumar R, Hubbell SP, Foster RB (1998) Predicting population trends from size distributions: a direct test in a tropical tree community. Am Nat 152:495–509CrossRefPubMedGoogle Scholar
9. Djossa B, Fahr J, Ayihouénou BT, Kalko E, Sinsin B (2008) Land use impact on Vitellaria paradoxa CF Gaerten stand structure and distribution patterns: a comparison of Biosphere Reserve of Pendjari in Atacora district in Benin. Agrofor Syst 72:205–220CrossRefGoogle Scholar
10. Eltahir EM, Wagner S. 2012. Assessment of Regeneration Situation in natural and in plantation parts of Elsareef Reserved forest, Kordofan Region, Sudan. In: Conference on International Research on Food Security, Natural Resource Management and Rural Development organised by: Georg-August UniversitätGöttingen and University of Kassel-Witzenhausen Tropentag 2012, Göttingen, Germany September 19–21, 2012
11. Fagg CW, Allison GE. 2004. Acacia senegal and Gum Arabic Trade. Oxford Forestry Institute, Tropical forestry papers. Oxford Forestry Institute, Oxford, p. 45–258
12. Franklin JF, Mitchell RJ, Palik B (2007) Natural disturbance and stand development principles for ecological forestry. USDA Forest Service, Newtown Square, pp 11–19CrossRefGoogle Scholar
13. Gebrekirstos A, Teketay D, Fetene M, Mitlohner R (2006) Adaptation of five co-occurring tree and shrub species to water stress and its implication in restoration of degraded lands. For Ecol Manag 229:259–267CrossRefGoogle Scholar
14. Geldenhuys CJ (1992) The use of diameter distributions in sustained-used management of forests: examples from Southern Africa. In: Piearce GD, Gumbo DJ (eds) The ecology and management of indigenous forests in Southern Africa processing of an international symposium Victoria Falls Zimbabwe 27–29 July 1992. Zimbabwe forestry Commission and SAREC, Harare, pp 154–167Google Scholar
15. Good NF, Good RE (1972) Population dynamics of tree seedlings and saplings in mature eastern hardwood forests. Bull Torrey Bot Club 99:172–178CrossRefGoogle Scholar
16. Gouwakinnou GN, Kindomihou V, Assogbadjo AE, Sinsin B (2009) Population structure and abundance of Sclerocarya birrea (A. Rich) Hochst subsp. birrea in two contrasting land-use systems in Benin. Int J Biodivers Conserv 1(6):194–201Google Scholar
17. Khan ML, Rai JPN, Tripathi RS (1987) Population structure of some tree species in disturbed and protected sub-tropical forests of NE India. Acta Oecol 8:247–255Google Scholar
18. Kiage LM, Liu KB, Walker ND, Lam N, Huh OK (2007) Recent land-cover/use change associated with land degradation in the Lake Baringo catchment, Kenya, East Africa: evidence from Landsat TM and ETM+. Int J Remote Sens 28(19):4285–4309CrossRefGoogle Scholar
19. Lelon JK. 2008. Uptake of micronutrients by Acacia senegal varieties and its possible effects on gum arabic quality. PhD thesis. School of physical sciences, University of Nairobi, Nairobi, pp. 105-128
20. Lykke AM (1998) Assessment of species composition change in savanna vegetation by means of woody plants’ size class distributions and local information. Biodivers Conserv 7:1261–1275CrossRefGoogle Scholar
21. Mayaux P, Holmgren P, Achard F, Eva H, Stibig HJ, Branthomme A (2005) Tropical forest cover change in the 1990s and options for future monitoring. Philos Trans R Soc Biol Sci 360:373–384CrossRefGoogle Scholar
22. Miles L, Newton AC, Defries RS, Ravilios C, May I, Blyth S, Kapos V, Gordon JE (2006) A global overview of the conservation status of tropical dry forest. J Biogeogr 33:491–505CrossRefGoogle Scholar
23. Muturi GM. 2012. Ecological impacts of Prosopis invasion in Riverine Forests of Kenya. PhD Thesis. School of Production Ecology and Resource Conservation, Wageningen University, Wageningen, pp. 2-6
24. Mwavu EN, Witkowski ETF (2009) Population structure and regeneration of multiple-use tree species in a semi-deciduous African tropical rainforest: implications for Primate Conservation. For Ecol Manag 258:840–849CrossRefGoogle Scholar
25. Neelo J, Teketay D, Masamba W, Kashe K (2013) Diversity, population structure and regeneration status of woody species in dry woodlands adjacent to Molapo farms in northern Botswana. Forestry 3(4):138–151Google Scholar
26. Obiri J, Lawes M. 2000. The sustainable use of timber and non-timber products: a case study from Umzimvubu District Pondoland South Africa. In: Seydack AHW, Vermeulen WJ, Vermeulen C (eds) Towards Sustainable Management Based on Scientific Understanding of Natural Forests and Woodlands. Proceedings of a Natural Forestsand Savanna Woodlands Symposium II, 5–9 September 1999. DWAF, Knysna, pp. 219-224
27. Obiri J, Lawes M, Mukolwe M (2002) The dynamics and sustainable use of high-value tree species of the coastal Pondoland forests of the Eastern Cape Province South Africa. For Ecol Manag 166:131–148CrossRefGoogle Scholar
28. Odee DW, Telford A, Wilson J, Gaye A, Cavers S (2012) Plio- Pleistocene history and phylogeography of Acacia senegal in dry woodlands and savannahs of sub-Saharan tropical Africa: evidence of early colonisation and recent range expansion. Heredity 109:372–382CrossRefPubMedPubMedCentralGoogle Scholar
29. Odee DW, Wilson J, Omondi S, Perry A, Cavers S (2015) Rangewide ploidy variation and evolution in Acacia senegal: a north-south divide? Ann Bot Plants. doi:10.1093/aobpla/plv011Google Scholar
30. Omondi FS, Kireger E, Dangasuk GO, Chikamai B, Odee DW, Cavers S, Khasa DP (2010) Genetic diversity and population structure of Acacia Senegal (L) Willd in Kenya. J Trop Plant Biol 3:59–70CrossRefGoogle Scholar
31. Otieno DO, Kinyamario JI, Omenda TO (2001) Growth features of Acacia tortilis and Acacia xanthophoea seedling and their response to cyclic soil drought stress. Afr J Ecol 39(21):126–132CrossRefGoogle Scholar
32. Rao P, Barik SK, Pandey HN, Tripathi RS (1990) Community composition and tree population structure in a sub-tropical broad-leaved forest along a disturbance gradient. Vegetatio 88:151–162CrossRefGoogle Scholar
33. Shackleton CM (1993) Demography and dynamics of the dominant woody species in a communal and protected area of the eastern Transvaal Lowveld. S Afr J Bot 59:569–574CrossRefGoogle Scholar
34. Shackleton CM, Griffin NJ, Banks DI, Mavrandonis JM, Shackleton SE (1994) Community structure and species composition along a disturbance gradient in a communally managed South African savanna. Vegetatio 115:157–167Google Scholar
35. Sokpon N, Biaou SH (2002) The use of diameter distributions in sustained-use management of remnant forests in Benin: case of Bassila Forest Reserve in North Benin. For Ecol Manag 161:13–25CrossRefGoogle Scholar
36. Sombroek WG, Braun HMH, Van der Pouw BJA (1982) Exploratory soil map and agro-climatic zone map of Kenya Scale 1:1 000 000. Exploratory Soil Survey Report No E1, Kenya Soil Survey, Nairobi, Kenya
37. Sop TK, Oldeland J, Schmiedel U, Ouedraogo I, Thiombiano A (2010) Population structure of three woody species in four ethnic domains of the Sub-Sahel of Burkina Faso. Land Degrad Dev 22(6):519–529CrossRefGoogle Scholar
38. Tabuti JRS (2007) The uses local perceptions and ecological status of 16 woody species of Gadumire Sub-county Uganda. Biodivers Conserv 16:1901–1916CrossRefGoogle Scholar
39. Teketay D (1996) Germination ecology of twelve indigenous and eight exotic multipurpose leguminous species from Ethiopia. For Ecol Manag 80:209–223CrossRefGoogle Scholar
40. Traore S, Kabore O, Rasolodimbi JM, Thiombiano L, Guinko S (2008) Impact of protected areas and land use on regeneration of acacia woodland’s in Eastern Burkina Faso. Flora et Vegetation Sudano-Sambesica 11:17–24Google Scholar
41. Venter SM, Witkowski ETF (2010) Baobab (Adansonia digitata L.) density, size-class distribution and population trends between four land-use types in northern Venda South Africa. For Ecol Manag 259:294–300CrossRefGoogle Scholar
42. Wassie A, Sterck F, Bonger F (2010) Species and structural diversity of church forests in fragmented Ethiopian highland landscape. J Veg Sci 21:938–948CrossRefGoogle Scholar
43. Wiegand K, Ward D, Thulke H, Jeltsch F (2000) From snapshot information to long-term population dynamics of Acacia by a simulation model. Plant Ecol 150:97–114CrossRefGoogle Scholar
44. Wilson BG, Witkowski ETF (2003) Seed banks, bark thickness, and changes in age and size structure (1978–1999) of the African savanna tree, Burkea Africana. Plant Ecol 167:151–162CrossRefGoogle Scholar
45. Witkowski ETF, Garner RD (2000) Spatial distribution of seed banks of three African savanna woody species at contrasting sites. Plant Ecol 149:91–106CrossRefGoogle Scholar
46. Witkowski K, Krol T, Eotocka M (1994) The light scattering matrix of Chlorella vulgaris cells and its variability due to cell modification. Oceanologia 36:19–31Google Scholar
47. Yadav AS, Gupta SK (2009) Natural regeneration of tree species in a tropical dry deciduous thorn forest in Rajasthan India. Bull Natl Inst Ecol 20:5–14Google Scholar
48. Yates CJ, Norton DA, Hobbes RJ (2000) Grazing effects on plant cover, soil and microclimate in fragmented woodlands in south west Australia: implication for restoration. Austral Ecol 25:36–47CrossRefGoogle Scholar
49. Yebeyen D (2006) Population status of Acacia senegal (linne) willdenow and its gum quality in the central rift valley of Ethiopia. Master’s thesis. Hawassa University, Wondogenet College of Forestry, Shashemene, Ethiopia, pp. 48-52

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