Journal of Forest and Environmental Science

  • 제38권2호
  • /
  • Pages.90-101
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  • 2022
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  • 2288-9744(pISSN)
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  • 2288-9752(eISSN)
강원대학교 산림과학연구소 (Institute of Forest Science, kangwon National University)
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Analysis of Composition and Diversity of Natural Regeneration of Woody Species in Jebel El Gerrie Dry Land Forest East of Blue Nile State, Sudan

  • 투고 : 2021.03.26
  • 심사 : 2022.06.04
  • 발행 : 2022.06.30
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초록

The study aims to assess composition, diversity and population indices of natural regeneration of woody species in Jebel El Gerrie forest reserve, Blue Nile State, Sudan. We conducted field work between December 2018 and January 2019. We used random sampling to collect vegetation data in the forest where we made a total of 90 circular sample plots (radius 17.84 m) and distributed them proportionally to the area of each of the four density-based vegetation classes of the forest i.e. high density (C1), medium density (C2), low density (C3) and crop land (C4). In each sample plot we identified all regenerating tree species and counted their regeneration frequencies. We calculated ecological metrics of regeneration frequency, density, abundance, richness, evenness, diversity and importance value index (IVI) and drew abundance rank curve. Results revealed that out of fifteen mature tree species present, natural regeneration of 8 species, which belong to 6 families, was observed. The relatively most frequently naturally regenerating and abundant species were Anogeissus leiocarpa and Combretum hartmannianum. Richness, evenness and diversity of regenerating species were 1.33, 0.82 and 1.7, respectively. One-way ANOVA (α=0.05) of mean regeneration densities disclosed that there were significant differences (F3,86=16.77, p=0.000) between C2 & C3 (p=0.000) and C2 & C4 (p=0.000). While regeneration of seven tree species were absent, two, two and four species were of good, poor and fair regeneration status, respectively. A comparison of mean density of natural regeneration with that of parent trees reflects a poor regeneration status of the forest. The study provides empirical results on the regeneration status of species and signifies the need for management interventions for species conservation and restoration, maintenance of biodiversity and sustainable production.

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과제정보

The authors acknowledge the support of the Ministry of Higher Education and Scientific Research (Sudan) in providing the research fund and the Forest National Corporation (FNC) for availing Jebel El Garrie forest reserve and its historical records for this study.

참고문헌

  1. Abiyu A, Bongers F, Eshete A, Gebrehiwot K, Kindu M, Lemenih M, Moges Y, Ogbazghi W, Sterck FJ. 2010. Incense woodlands in Ethiopia and Eritrea: regeneration problems and restoration possibilities. In: Degraded Forests in Eastern Africa: Management and Restoration (Bongers F, Tennigkeit T, eds). Earthscan, London, pp 133-152.
  2. Abtew AA, Pretzsch J, Mohamoud TE, Adam YO. 2012. Population Status of Boswellia papyrifera (Del.) Hochst in the Dry Woodlands of Nuba Mountains, South Kordofan State, Sudan. Agric For 54: 41-50.
  3. Abtew AA, Pretzsch J, Mohmoud TE, Adam YO. 2011. Population structure, density and natural regeneration of Boswellia Papyrifera (Del.) Hochst in Dry woodlands of Nuba Mountains, South Kordofan State, Sudan. In: Conference on International Research on Food Security; Bonn, Germany; October 5-7, 2011.
  4. Abtew AA, Pretzsch J, Secco L, Mahmoud TE. 2014. Comparative Analysis of Gum and Resin Value Chains and their Rural Development Potentials in the Dry lands of Ethiopia and Sudan. In: Tropentag; Prague, Czech Republic; September 17-19, 2014.
  5. Abuelbashar AI. 2020. Socio-economic and technical factors influencing production and marketing of frankincense in Blue Nile state, Sudan. MS thesis. University of Khartoum, Khartoum, Sudan.
  6. Abyot D, Teshome S, Ensermu K, Abiyou T. 2014. Diversity, Structure and Regeneration Status of the Woodland and Riverine Vegetation of Sire Beggo in Gololcha District, Eastern Ethiopia. Momona Ethiop J Sci 6: 70-96. https://doi.org/10.4314/mejs.v6i1.102416
  7. Adam AA, El Tayeb AM. 2008. A Comparative Study of Natural Regeneration of B. papyrifera and Other Tree Species in Jebel Marra Darfur; Sudan. Res J Agric Biol Sci 4: 94-102.
  8. Addisalem AB, Bongers F, Kassahun T, Smulders MJM. 2016. Genetic diversity and differentiation of the frankincense tree (Boswellia papyrifera (Del.) Hochst) across Ethiopia and implications for its conservation. For Ecol Manag 360: 253-260. https://doi.org/10.1016/j.foreco.2015.10.038
  9. Aide TM, Clark ML, Grau HR, Lopez-Carr D, Levy MA, Redo D, Bonilla-Moheno M, Riner G, Andrade-Nunez MJ, Muniz M. 2013. Deforestation and Reforestation of Latin America and the Caribbean (2001-2010). Biotropica 45: 262-271. https://doi.org/10.1111/j.1744-7429.2012.00908.x
  10. Alemu B, Eshetu Z, Garedew E, Kassa H. 2015. Assessment of vegetation characteristics and production of Boswellia papyrifera woodlands in north western lowlands of Ethiopia. Sky J Agric Res 4: 8-13.
  11. Aliyi K, Hundera K, Dalle G. 2015. Floristic Composition, Vegetation Structure and Regeneration Status of Kimphe Lafa Natural Forest, Oromia Regional State, West Arsi, Ethiopia. Res Rev J Life Sci 5: 19-32.
  12. Austin MP. 1977. Use of ordination and other multivariate descriptive methods to study succession. Vegetatio 35: 165-175. https://doi.org/10.1007/BF02097067
  13. Avila MA, Mota NM, Souza SR, Santos R, Nunes YRF. 2021. Diversity and Structure of Natural Regeneration in Swamp Forests in Southeastern Brazil. Floresta Ambient 28: e20190110. https://doi.org/10.1590/2179-8087-floram-2019-0110
  14. Badi KH, Abdel Magid T. 2013. Manual of Silviculture for Selected Trees in Sudan. LAP Lambert Academic Publishing, Saarbrucken.
  15. Bhadra AK, Pattanayak SK. 2016. Abundance or dominance: which is more justified to calculate importancevalue index (IVI) of plant species? Asian J Sci Technol 7: 3577-3601.
  16. Bongers F, Groenendijk P, Bekele T, Birhane E, Damtew A, Decuyper M, Eshete A, Gezahgne A, Girma A, Khamis MA, Lemenih M, Mengistu T, Ogbazghi W, Sass-Klaassen U, Tadesse W, Teshome M, Tolera M, Sterck FJ, Zuidema PA. 2019. Frankincense in peril. Nat Sustain 2: 602-610. https://doi.org/10.1038/s41893-019-0322-2
  17. Brower JE, Zar JH. 1977. Field and laboratory methods for general ecology. Wm. C. Brown Company Publishers, Dubuque, IA.
  18. Chazdon RL, Lindenmayer D, Guariguata MR, Crouzeilles R, Benayas JNR, Chavero EL. 2020. Fostering natural forest regeneration on former agricultural land through economic and policy interventions. Environ Res Lett 15: 043002. https://doi.org/10.1088/1748-9326/ab79e6
  19. Darbyshire I, Kordofani M, Farag I, Candiga R, Pickering H. 2015. The plants of Sudan and South Sudan: an annotated checklist. Royal Botanic Gardens, Kew, Richmond.
  20. Dereje OA, Duguma ID. 2019. Woody Species Composition and Natural Regeneration Status of Ades Forest, Oromia Regional State, West Hararghe Zone, Ethiopia. J Trop For Environ 9: 27-36.
  21. Dhaulkhandi M, Dobhal A, Bhatt S, Kumar M. 2008. Community structure and regeneration potential of natural forest site in Gangotri, India. J Basic Appl Sci 4: 49-52.
  22. El Amin HM. 1983. Trees and shrubs of Sudan. PhD thesis. University of Khartoum, Khartoum, Sudan.
  23. El Amin HM. 1990. Trees and shrubs of the Sudan. Ithaca Press, Exeter.
  24. Eshete A, Sterck F, Bongers F. 2011. Diversity and production of Ethiopian dry woodlands explained by climate- and soil-stress gradients. For Ecol Manag 261: 1499-1509. https://doi.org/10.1016/j.foreco.2011.01.021
  25. Eshete A, Teketay D, Hulten H. 2005. The socio-economic importance and status of populations of Boswellia papyrifera (Del.) Hochst. in Northern Ethiopia: the case of North Gonder Zone. For Trees Livelihoods 15: 55-74. https://doi.org/10.1080/14728028.2005.9752507
  26. Eshete A, Teketay D, Lemenih M, Bongers F. 2012. Effects of resin tapping and tree size on the purity, germination and storage behavior of Boswellia papyrifera (Del.) Hochst. seeds from Metema District, northwestern Ethiopia. For Ecol Manag 269: 31-36. https://doi.org/10.1016/j.foreco.2011.12.049
  27. FAO. 2004. National Forest Inventory Field Manual Template. Forest Resources Assessment Programme Working Paper 94/E. FAO, Rome.
  28. FAO. 2015. Global Forest Resource Assessment 2014. Country Report Sudan.
  29. FAO. 2020. Global Forest Resources Assessments 2020 Report Sudan. FAO, Rome.
  30. Frerebeau N. 2019. Diversity Measures. https://cran.r-project.org/web/packages/tabula/. Accessed 10 Feb 2021.
  31. Gebeyehu G, Soromessa T, Bekele T, Teketay D. 2019. Species composition, stand structure, and regeneration status of tree species in dry Afromontane forests of Awi Zone, northwestern Ethiopia. Ecosyst Health Sustain 5: 199-215. https://doi.org/10.1080/20964129.2019.1664938
  32. Gebrehiwot K, Muys B, Haile M, Mitloehner R. 2003. Introducing Boswellia papyrifera (Del.) Hochst and its non-timber forest product, frankincense. Int For Rev 5: 348-353.
  33. Gibreel H, Kordofani MAY, Warrag EI, Ahmed HO. 2013. Medicinal value and ecotaxonomy of the flora of Blue Nile State-Sudan. J Chem Pharm Res 5: 36-43.
  34. Gibreel HH. 2008. A taxonomic study on trees and shrubs of El Nour natural forest reserve, Blue Nile State-Sudan. MS thesis. University of Khartoum, Khartoum, Sudan.
  35. Gidey T, Hagos D, Juhar HM, Solomon N, Negussie A, Crous-Duran J, Oliveira TS, Abiyu A, Palma JHN. 2020. Population status of Boswellia papyrifera woodland and prioritizing its conservation interventions using multi-criteria decision model in northern Ethiopia. Heliyon 6: e05139. https://doi.org/10.1016/j.heliyon.2020.e05139
  36. Glen WM. 1996. National Forest Inventory for the Sudan. FAO, Rome.
  37. Good NF, Good RE. 1972. Population Dynamics of Tree Seedlings and Saplings in a Mature Eastern Hardwood Forest. Bull Torrey Bot Club 99: 172-178. https://doi.org/10.2307/2484571
  38. Gotelli NJ, Ellison AM. 2012. A Primer of Ecological Statistics. 2nd ed. Sinauer Associates, Sunderland, MA.
  39. Groenendijk P, Eshete A, Sterck FJ, Zuidema PA, Bongers F. 2012. Limitations to sustainable frankincense production: blocked regeneration, high adult mortality and declining populations. J Appl Ecol 49: 164-173. https://doi.org/10.1111/j.1365-2664.2011.02078.x
  40. Grubb PJ. 1977. The maintenance of species-richness in plant communities: the importance of the regeneration niche. Biol Rev 52: 107-145. https://doi.org/10.1111/j.1469-185X.1977.tb01347.x
  41. Gurmessa F, Soromessa T, Kelbessa E. 2013. Floristic Composition and Community Analysis of Komto Afromontane Moist Forest, East Wollega Zone, West Ethiopia. Sci Technol Arts Res J 2: 58-69. https://doi.org/10.4314/star.v2i2.98887
  42. Haider M, Alam S, Mohiuddin M. 2018. Regeneration potentials of native tree species in three natural forests of Sylhet, Bangladesh. J Biodivers Conserv Bioresour Manag 3: 1-10. https://doi.org/10.3329/jbcbm.v3i2.36023
  43. Haile G, Gebrehiwot K, Lemenih M, Bongers F. 2011. Time of collection and cutting sizes affect vegetative propagation of Boswellia papyrifera (Del.) Hochst through leafless branch cuttings. J Arid Environ 75: 873-877. https://doi.org/10.1016/j.jaridenv.2011.04.007
  44. Henle K, Lindenmayer DB, Margules CR, Saunders DA, Wissel C. 2004. Species survival in fragmented landscapes: where are we now? Biodivers Conserv 13: 1-8. https://doi.org/10.1023/B:BIOC.0000004311.04226.29
  45. Ismail I, Elawad A. 2015. Checklist of plants of Rashad and Alabassia localities (eastern Nuba Mountains), South Kordofan Sudan. Check List 11: 1805. https://doi.org/10.15560/11.6.1805
  46. Jannat M, Kamruzzaman M, Kamal Hossain M. 2020. Assessment of natural regeneration potential of native tree species in a community managed forest of Bangladesh. Int J Environ 9: 100-114. https://doi.org/10.3126/ije.v9i1.27598
  47. Kadavul K, Parthasarathy N. 1999. Plant biodiversity and conservation of tropical semi-evergreen forest in the Shervarayan hills of Eastern Ghats, India. Biodivers Conserv 8: 421-439.
  48. Karami A, Karamshahi A, Shahi E. 2017. Effects of forestry practices on the regeneration and biodiversity of woody plants in the northern forest ecosystems of Iran. Geol Ecol Landsc 1: 264-270. https://doi.org/10.1080/24749508.2017.1389503
  49. Khamis M, El Siddig E, Khalil A, Csaplovics E. 2016. Changes in forest cover composition of Boswellia papyrifera (Del.) Hochst. Stands and their consequences, South Kordofan, Sudan. Mediterr J Biosci 1: 99-108.
  50. Khamis MA. 2001. Management of Boswellia papyrifera stands for resin production in Jebel Marra Area, Western. Sudan, present situation and future prospects. MS thesis. Technische Universitat, Dresden, Germany.
  51. Khan ML, Rai JPN, Tripathi RS. 1987. Population structure of some tree species in disturbed and protected subtropical forests of north-east India. Acta Oecol Ecol Appl 8: 247-255.
  52. Koffi G, Worms P. 2021. Niger Formally Adopts Farmer-Managed Natural Regeneration. https://www.worldagroforestry.org/blog/2021/01/12/niger-formally-adopts-farmer-managed-naturalregeneration. Accessed 10 Apr 2022.
  53. Lemenih M, Arts B, Wiersum KF, Bongers F. 2014. Modelling the future of Boswellia papyrifera population and its frankincense production. J Arid Environ 105: 33-40. https://doi.org/10.1016/j.jaridenv.2014.02.006
  54. Magurran AE. 2004. Measuring Biological Diversity. Wiley-Blackwell, Oxford.
  55. Malik ZA, Youssouf M, Singh S, Bhatt AB. 2017. Tree regeneration status and population structure along the disturbance gradient (a case study from western Himalaya). ENVIS Bull Himal Ecol 25: 81-93.
  56. Maua JO, MugatsiaTsingalia H, Cheboiwo J, Odee D. 2020. Population structure and regeneration status of woody species in a remnant tropical forest: a case study of South Nandi forest, Kenya. Glob Ecol Conserv 21: e00820. https://doi.org/10.1016/j.gecco.2019.e00820
  57. Mekonnen Z, Worku A, Yohannes T, Bahru T, Mebratu T, Teketay D. 2013. Economic Contribution of Gum and Resin Resources to Household Livelihoods in Selected Regions and the National Economy of Ethiopia. Ethnobot Res Appl 11: 273-288.
  58. Mengistu T, Sterck FJ, Anten NPR, Bongers F. 2012. Frankincense tapping reduced photosynthetic carbon gain in Boswellia papyrifera (Burseraceae) trees. For Ecol Manag 278: 1-8. https://doi.org/10.1016/j.foreco.2012.04.029
  59. MoAARF (Ministry of Agriculture, Animal Resources and Forestry). 2014. Livestock production. Food Security Technical Secretariat (FSTS), Blue Nile State. Livestock Policy Brief No.1/February 2014.
  60. Mishra AK, Bajpai O, Sahu N, Kumar A, Behera SK, Mishra R, Chaudhary LB. 2013. Study of plant regeneration potential in tropical moist deciduous forest In Northern India. Int J Environ 2: 153-163. https://doi.org/10.3126/ije.v2i1.9218
  61. Misra R. 1968. Ecology Work Book. Oxford and IBH, Calcutta.
  62. Mohammed EMI, H EAM, Ndakidemi PA, Treydte AC. 2021. Anthropogenic Pressure on Tree Species Diversity, Composition, and Growth of Balanites aegyptiaca in Dinder Biosphere Reserve, Sudan. Plants (Basel) 10: 483.
  63. Musa MS, Abdelrasool FE, Elsheikh EA, Ahmed LAMN, Mahmoud ALE, Yagi SM. 2011. Ethnobotanical study of medicinal plants in the Blue Nile State, South-eastern Sudan. J Med Plants Res 5: 4287-4297.
  64. Neelo J, Teketay D, Kashe K, Masamba W. 2015. Stand Structure, Diversity and Regeneration Status of Woody Species in Open and Exclosed Dry Woodland Sites around Molapo Farming Areas of the Okavango Delta, Northeastern Botswana. Open J For 5: 313-328.
  65. 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. Open J For 3: 138-151.
  66. Negussie A, Aerts R, Gebrehiwot K, Muys B. 2008. Seedling mortality causes recruitment limitation of Boswellia papyrifera in northern Ethiopia. J Arid Environ 72: 378-383. https://doi.org/10.1016/j.jaridenv.2007.06.009
  67. Nour LAM. 2008. Production and productivity of Boswellia papyrifera in Jebel Elgarrie area (Blue Nile State). MS thesis. University of Khartoum, Khartoum, Sudan. (in English)
  68. Odum E. 1971. Fundamentals of Ecology. Saunders, Philadelphia, PA.
  69. Ogbazghi W, Bongers F, Rijkers A, Wessel M. 2006. Population structure and morphology of the frankincense tree Boswellia papyrifera along an altitude gradient in Eritrea. J Drylands 1: 85-94.
  70. Ogbazghi W. 2001. The distribution and regeneration of Boswellia papyrifera (Del.) Hochst. in Eritrea. PhD thesis. Wageningen University, Wageningen, The Netherlands. (in English)
  71. Okpiliya FI. 2012. Ecological Diversity Indices: Any Hope for One Again? J Environ Earth Sci 2: 45-52.
  72. Omer AHA. 2013. Adansonia digitata: structure, density, important uses, and potential habitat in Blue Nile and Sinnar States, Sudan. MS thesis. University of Khartoum, Khartoum, Sudan. (in English)
  73. Osman EH, Gumaa YSA, Elhag AMH. 2018. Land Cover/Land Use Trends along the Blue Nile River Blue Nile State - Sudan. Int J Appl Sci 13: 1-13.
  74. Pokhriyal P, Uniyal P, Chauhan DS, Todaria NP. 2010. Regeneration Status of Tree Species in Forest of Phakot and Pathri Rao Watersheds in Garhwal Himalaya. Curr Sci 98: 171-175.
  75. Rahman MH, Khan MASA, Roy B, Fardusi MJ. 2011. Assessment of natural regeneration status and diversity of tree species in the biodiversity conservation areas of Northeastern Bangladesh. J For Res 22: 551-559. https://doi.org/10.1007/s11676-011-0198-0
  76. Rahman R, Rahman M, Chowdhury A. 2020. Assessment of natural regeneration status: the case of Durgapur hill forest, Netrokona, Bangladesh. Geol Ecol Landsc 4: 121-130. https://doi.org/10.1080/24749508.2019.1600911
  77. Rayner J, Buck A, Katila P. 2010. Embracing Complexity: Meeting the Challenges of International Forest Governance. International Union of Forest Research Organizations (IUFRO), Vienna.
  78. Rehman NU, Al-Shidhani S, Al-Harrasi A, Al-Rawahi A, Mabood F, Al-Broumi M, Al-Azri M, Alam T, Hussain J. 2020. Analysis of incensole acetate in Boswellia species by near infrared spectroscopy coupled with partial least squares regression and cross-validation by high-performance liquid chromatography. J Near Infrared Spectrosc 28: 18-24. https://doi.org/10.1177/0967033519895689
  79. Sabo P, Ouedraogo A, Gbemavo DSJC, Salako KV, Glele Kakai R. 2021. Land use impacts on Boswellia dalzielii Hutch., an African frankincense tree in Burkina Faso. Bois For Trop 349: 51-63.
  80. Saha S, Rajwar GS, Kumar M. 2016. Forest structure, diversity and regeneration potential along altitudinal gradient in Dhanaulti of Garhwal Himalaya. For Syst 25: e058.
  81. Salih AA, Yousif E, Khamis MA. 2002. Country report for Sudan. In: Review and Synthesis on the State of Knowledge of Boswellia Species and Commercialization of Frankincense in the Dry Lands of Eastern Africa (Chikamai BN, ed). FAO, Rome.
  82. Sauder DC, DeMars CE. 2019. An Updated Recommendation for Multiple Comparisons. Adv Methods Pract Psychol Sci 2: 26-44. https://doi.org/10.1177/2515245918808784
  83. Saxena AK, Singh JS. 1984. Tree population structure of certain Himalayan forest associations and implications concerning their future composition. Vegetatio 58: 61-69. https://doi.org/10.1007/BF00044928
  84. Saxena AK, Singh SP, Singh JS. 1984. Population structure of forests of Kumaun Himalaya: implications for management. J Environ Manag 19: 307-324.
  85. Shankar U. 2001. A case of high tree diversity in a sal (Shorea robusta)-dominated lowland forest of Eastern Himalaya: floristic composition, regeneration and conservation. Curr Sci 81: 776-786.
  86. Shibru S. 2002. Inventory of woody species in Dindin Forest. Technical Report No. 01. IBCR/GTZ/FGRCP.
  87. Shukla RS, Chandel PS. 2000. Plant Ecology and Soil Science. 9th ed. Chand and Company Limited, New Delhi.
  88. Siddig AAH. 2019. Why is biodiversity data-deficiency an ongoing conservation dilemma in Africa? J Nat Conserv 50: 125719. https://doi.org/10.1016/j.jnc.2019.125719
  89. Sommerlatte H, Wyk B-EV. 2022. Observations on the Association between Some Buprestid and Cerambycid Beetles and Black Frankincense Resin Inducement. Diversity 14: 58. https://doi.org/10.3390/d14010058
  90. Sundriyal RC, Sharma E, Rai LK, Rai SC. 1994. Tree structure, regeneration and woody biomass removal in a sub-tropical forest of Mamlay watershed in the Sikkim Himalaya. Vegetatio 113: 53-63. https://doi.org/10.1007/BF00045463
  91. Tiwari GPK, Tadele K, Aramde F, Tiwari SC. 2010. Community Structure and Regeneration Potential of Shorea robusta Forest in Subtropical Submontane Zone of Garhwal Himalaya, India. Nat Sci 8: 70-74.
  92. Tolera M, Sass-Klaassen U, Eshete A, Bongers F, Sterck FJ. 2013. Frankincense tree recruitment failed over the past half century. For Ecol Manag 304: 65-72. https://doi.org/10.1016/j.foreco.2013.04.036
  93. Tripathi RS, Khan ML. 2007. Regeneration Dynamics of Natural Forests- A Review. Proc Indian Natl Sci Acad 73: 167-195.
  94. Woldie TM. 2011. Physiological ecology of the frankincense tree. PhD thesis. Wageningen University, Wageningen, The Netherlands. (in English)
  95. Yakubu M, Saka MG, Sa'idu I, Mahmud WA, Yunus AU. 2020. Assessment of the Checklist and Regeneration Status Potential of Species Seedlings and Saplings of Baturiya Hadejia Wetland Game Reserve, Jigawa State, Nigeria. Glo Adv Res J Agric Sci 9: 19-26.
  96. Yang X, Yan D, Liu C. 2014. Natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China. PLoS One 9: e108744. https://doi.org/10.1371/journal.pone.0108744
  97. Yeom DJ, Kim JH. 2011. Comparative evaluation of species diversity indices in the natural deciduous forest of Mt. Jeombong. For Sci Technol 7: 68-74.
  98. Zegeye H, Teketay D, Kelbessa E. 2011. Diversity and regeneration status of woody species in Tara Gedam and Abebaye forests, northwestern Ethiopia. J For Res 22: 315-328. https://doi.org/10.1007/s11676-011-0176-6