Article

Gideon A. Mseja, MSc, Assistant Lecturer, Department of Wildlife Management, College of African Wildlife Management (P.O. Box 3031, Moshi, Tanzania); e-mail: galfred@mwekawildlife.ac.tz
Beatrice B. Furael, MSc, Assistant Lecturer, Department of Tourism, College of African Wildlife Management (P.O. Box 3031, Moshi, Tanzania); e-mail: bbenjamin@mwekawildlife.ac.tz
Gastor J. Lyakurwa, MSc, Assistant Lecturer, Department of Wildlife Management, College of African Wildlife Management (P.O. Box 3031, Moshi, Tanzania); e-mail: glyakurwa@mwekawildlife.ac.tz
Emanuel H. Martin, PhD, Lecturer, Department of Wildlife Management, College of African Wildlife Management (P.O. Box 3031, Moshi, Tanzania); e-mail: emartin@mwekawildlife.ac.tz

Mseja G.A., Furael B.B., Lyakurwa G.J., Martin E.H. 2020. Herbaceous vegetation communities around lake Manyara, Tanzania: response to environmental gradients. Nature Conservation Research 5(4): 55–64. https://dx.doi.org/10.24189/ncr.2020.056

Healthy populations of wildlife require quality forage sufficiently available in both space and time. The herbaceous vegetation around rift valley lakes in Tanzania varies along productivity, disturbance and stress gradients. We have analysed herbaceous vegetation communities and ascertained the nature of their association with environmental variables around Lake Manyara in Kwakuchinja Wildlife Corridor. The transect method was used for sampling vegetation data. Environmental variables including soil pH, available soil phosphorus, distance from the lakeshore, bare soils, soil water, soil salinity and soil total nitrogen were used as possible explanatory variables. Ordination was used to assemble the herbaceous plant communities and relate with the determined environmental variables. The Shannon-Wiener Index was employed to determine species diversity in each plant community. The results revealed three distinct grassland communities named after the dominant and subdominant species: Sporobolus spicatus, Sporobolus ioclados – S. spicatus and Cynodon dactylon. The Monte Carlo Permutation test revealed that soil pH, available soil phosphorus, distance from the lakeshore and bare soil significantly correlated with herbaceous plant community assemblages. The indices of plant species richness and diversity reflected the influence of soil saturation gradients on plant communities. This study contributes to understanding spatial patterns of herbaceous plant communities around alkaline-saline lakes of the Gregory rift valley in East Africa. It also reveals an association between plant community structures with varying edaphic gradients. We conclude that our study forms the basis for monitoring herbaceous plant community change based on determined environmental variables in the corridors of wildlife conservation areas.

CANOCO, eigen-value, Kwakuchinja Wildlife Corridor, Monte-Carlo, simulation

Received: 24.07.2019. Revised: 02.09.2020. Accepted: 08.09.2020.

Aarrestad P.A., Masunga G.S., Hytteborn H., Pitlagano M.L., Marokane W., Skarpe C. 2010. Influence of soil, tree cover and large herbivores on field layer vegetation along a savanna landscape gradient in Northern Botswana. Journal of Arid Environments 75(3): 290–297. DOI: 10.1016/j.jaridenv.2010.10.009
Augustine D.J., McNaughton S.J. 1998. Ungulate Effects on the Functional Species Composition of Plant Communities: Herbivore Selectivity and Plant Tolerance. Journal of Wildlife Management 62(4): 1165–1183. DOI: 10.2307/3801981
Bachofer F., Quénéhervé G., Märker M. 2014. The delineation of paleo-shorelines in the Lake Manyara basin using TerraSAR-X data. Remote Sensing 6(3): 2195–2212. DOI: 10.3390/rs6032195
Begon M., Townsend C.R., Harper J.L. 2006. Ecology: From Individuals to Ecosystems. 4^th ed. Blackwell Publishing. 738 p.
Bremner J.M., Mulvaney C.S. 1982. Nitrogen total. In: A.L. Page, R.H. Miller, D.R. Keeney (Eds.): Methods of soil analysis. Madison: American Society of Agronomy and Soil Science Society of America. P. 595–624.
Bryant J.P., Chapin F.S., Klein D.R. 1983. Carbon/nutrient balance of boreal plants in relation to vertebrate herbivory. Oikos 40(3): 357–368. DOI: 10.2307/3544308
Connel J.H., Orias E. 1964. The Ecological Regulation of Species Diversity. The American Naturalist 98(903): 399–414.
Cornwell W.K., Grubb P.J. 2003. Regional and local patterns in plant species richness with respect to resource availability. Oikos 100(3): 417–428. DOI: 10.1034/j.1600-0706.2003.11697.x
Craine J.M., Morrow C., Stock W.D. 2008. Nutrient concentration ratios and co-limitation in South African grasslands. New Phytologist 179(3): 829–836. DOI: 10.1111/j.1469-8137.2008.02513.x
De Neve S., Hofman G. 2002. Quantifying soil water effects on nitrogen mineralization from soil organic matter and from fresh crop residues. Biology and Fertility of Soils 35(5): 379–386. DOI: 10.1007/s00374-002-0483-3
Gaston K.J. 2000. Global patterns in biodiversity. Nature 405: 220–227. DOI: 10.1038/35012228
Gauch H.G. 1982. Multivariate analysis in community ecology. Portland: Cambridge University Press. P. 109–172.
Ghazanfar S.A. 2006. Saline and alkaline vegetation of NE Africa and the Arabian Peninsula: An overview. In Biosaline Agriculture and Salinity Tolerance in Plants. Basel: Birkhäuser. P. 101–108.
Golodets C., Sternberg M., Kigel J., Boeken B., Henkin Z., Seligman N.G., Ungar E.U. 2013. From desert to Mediterranean rangelands: will increasing drought and inter-annual rainfall variability affect herbaceous annual primary productivity? Climatic Change 119(3–4): 785–798. DOI: 10.1007/s10584-013-0758-8
Grime J.P. 1973. Control of species density on herbaceous vegetation. Journal of Environmental Management 1: 151–167.
Harrison A.K., Bardgett R.D. 2008. Impacts of grazing and browsing by large mammals on soils and soil biological properties. In: I.J. Gordon, H.H.T. Prins (Eds.): The Ecology of Browsing and Grazing. Heidelberg: Springer. P. 201–202.
Holdo R.M., Holt R.D., Fryxell J.M. 2009. Grazers, browsers, and fire influence the extent and spatial pattern of tree cover in the Serengeti. Ecological Applications 19(1): 95–109. DOI: 10.1890/07-1954.1
Homewood K.M., Trench P.C., Brockington D. 2012. Pastoralist livelihoods and wildlife revenues in East Africa: a case for coexistence? Pastoralism: Research, Policy and Practice 2(1): 19. DOI: 10.1186/2041-7136-2-19
Huston M. 1979. A general hypothesis of species diversity. The American Naturalist 113(1): 81–101. DOI: 10.1086/283366
Jones J. 2018. Soil analysis handbook of reference methods. CRC Press. 264 p.
Jongman R.H.G., ter Braak C.J.F., Van Tongeren O.F.R. 1995. Data analysis in community and landscape ecology. Portland: Cambridge University Press. 111 p.
Larcher W. 2003. Physiological Plant Ecology. 4^thed. Berlin: Springer Verlag. 514 p.
Lepš J., Šmilauer P. 2003. Multivariate Analysis of Ecological Data Using CANOCO. Cambridge: Cambridge University Press. 269 p. DOI: 10.1017/CBO9780511615146
Li F., Pennings S.C. 2019. Response and Recovery of Low-Salinity Marsh Plant Communities to Presses and Pulses of Elevated Salinity. Estuaries and Coasts 42(3): 708–718. DOI: 10.1007/s12237-018-00490-1
Makhabu S.W., Marotsi B., Perkins J. 2002. Vegetation gradients around artificial water points in the Central Kalahari Game Reserve of Botswana. African Journal of Ecology 40(2): 103–109. DOI: 10.1046/j.1365-2028.2002.00306.x
McGarigal K., Cushman S.A., Stanford S. 2013. Multivariate Statistics for Wildlife and Ecology Research. Springer Science and Business Media. 282 p.
Milchunas D.G., Lauenroth W.K. 1993. Quantitative effects of grazing on vegetation and soils over a global range of environments. Ecological Monographs 63(4): 327–366. DOI: 10.2307/2937150
Milchunas D.G., Sala O.E., Lauenroth W.K. 1988. A generalized model of the effects of grazing by large herbivores on grassland community structure. The American Naturalist 132(1): 87–106. DOI: DOI: 10.1086/284839
Mubyana T., Krah M., Totolo O., Bonyongo M. 2003. Influence of seasonal flooding on soil total nitrogen, organic phosphorus and microbial populations in the Okavango Delta, Botswana. Journal of Arid Environments 54(2): 359–369. DOI: 10.1006/jare.2002.1095
Mutakyahwa M.K.D. 2002. Mineralogy and chemistry of bentonite (?) deposits at Minjingu, Lake Manyara, North Tanzania. Journal of African Earth Sciences 34(3–4): 213–221. DOI: 10.1016/S0899-5362(02)00020-9
Olsen S.R., Cole C.V., Watanabe F.S., Dean L.A. 1954. Estimation of available phosphorus in soils by extraction with Sodium bicarbonate. New York: U.S Department of Agriculture, Circular 939, 19 p.
Onkware A.O. 2000. Effect of soil salinity on plant distribution and production at Loburu delta, Lake Bogoria National Reserve, Kenya. Austral Ecology 25(2): 140–149. DOI: 10.1046/j.1442-9993.2000.01020.x
Oudtshoorn F.V. 2012. Guide to Grasses of Southern Africa. Pretoria: Briza Publications. 288 p.
POWO. 2020. Plants of the World Online. Facilitated by the Royal Botanic Gardens. Available from http://www.plantsoftheworldonline.org
Pratt D.J., Gwynne M.D. (Eds.). 1977. Rangeland Management and Ecology in East Africa. London; Sydney; Auckland; Toronto: Hodder & Stoughton. 310 p.
Scholes R.J., Walker B.H. 1993. An African savanna: synthesis of the Nylsvley study. Cambridge: Cambridge University Press. 236 p.
terBraak C.J.F., Šmilauer P. 2002. CANOCO Reference Manual and CanoDraw for Windows User's Guide: Software for Canonical Community Ordination (Version 4.5). New York: Microcomputer Power, Ithaca. 500 p.
The Plant List. 2013. The Plant List, version 1.1. Available from http://www.theplantlist.org
Van Langevelde F., Van De Vijver C.A., Kumar L., Van De Koppel J., De Ridder N., Van Andel J., Skidmore A.K., Hearne J.W., Stroosnijder L., Bond W.J., Prins H.H. 2003. Effects of fire and herbivory on the stability of savanna ecosystems. Ecology 84(2): 337–350. DOI: 10.1890/0012-9658(2003)084[0337:EOFAHO]2.0.CO;2
Wilsey B. 2002. Clonal plants in a spatially heterogeneous environment: effects of integration on Serengeti grassland response to defoliation and urine-hits from grazing mammals. Plant Ecology 159(1): 15–22. DOI: 10.1023/A:1015556816307
Wilson S.D., Tilman D. 2002. Quadratic variation in old-field species richness along gradients of disturbance and nitrogen. Ecology 83(2): 492–504. DOI: 10.2307/2680030
Wüest R.O., Münkemüller T., Lavergne S., Pollock L.J., Thuiller W. 2018. Integrating correlation between traits improves spatial predictions of plant functional composition. Oikos 127(3): 472–481. DOI: 10.1111/oik.04420
Yanda P.Z., Madulu N.F. 2005. Water resource management and biodiversity conservation in the Eastern Rift Valley Lakes, Northern Tanzania. Physics and Chemistry of the Earth 30(11): 717–725. DOI: 10.1016/j.pce.2005.08.013