Volume 2, Issue 5, September 2017, Page: 85-93
Time Series Monitoring of Bush Encroachment by Euclea divinorum in Ol Pejeta Conservancy Laikipia, Kenya
Cyrus Mutunga Kavwele, Department of Natural Resources, Karatina University, Nyeri, Kenya
Mwangi James Kinyanjui, Department of Natural Resources, Karatina University, Nyeri, Kenya
Johnstone Kithiki Kimanzi, Department of Wildlife Management, University of Eldoret, Eldoret, Kenya
Received: Jun. 10, 2017;       Accepted: Jun. 28, 2017;       Published: Aug. 1, 2017
DOI: 10.11648/j.ijnrem.20170205.11      View  1951      Downloads  118
Abstract
Bush encroachment refers to the invasion of woody species in Savannah ecosystems driven by either anthropogenic and/or natural factors. This study sought to examine land cover changes and topographic features attributable to patterns of encroachment in Ol Pejeta Conservancy (OPC) where, Euclea divinorum unpalatable woody species has colonised former grasslands and other habitats which provide grazing grounds for herbivore wildlife species. Here, we monitored vegetation cover trends in the period 1987-2016 using five vegetation classes on Landsat images acquired during the dry season. Additionally, slope based NDVI maps and digital elevation models were used to identify topographic influences on vegetation change. Results revealed that E. divinorum increased significantly between 1987 and 2016 (Mann Kendall test for trend analysis tau 1, n=6, p< 0.01). On the other hand, Acacia drepanolobium and Acacia xanthophloea decreased from 49.72% and 5.31% in 1987 to 17.00% and 0.29% in 2016 respectively. Further, areas in low elevation were more colonised by E. divinorum. The colonising E. divinorum is unpalatable hence lacks natural predators whilst, A. drepanolobium and A. Xanthophloea which are alternative herbivory species decreased. Understanding dynamics of woody vegetation in savannah is crucial for management of healthy and sustainable ecosystems.
Keywords
Bush Encroachment, Savannah Grassland, Land Cover Change
To cite this article
Cyrus Mutunga Kavwele, Mwangi James Kinyanjui, Johnstone Kithiki Kimanzi, Time Series Monitoring of Bush Encroachment by Euclea divinorum in Ol Pejeta Conservancy Laikipia, Kenya, International Journal of Natural Resource Ecology and Management. Vol. 2, No. 5, 2017, pp. 85-93. doi: 10.11648/j.ijnrem.20170205.11
Copyright
Copyright © 2017 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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