TY - JOUR
T1 - Composition, structure, and regeneration patterns in a gallery forest along the Tana River near Bura, Kenya
AU - Maingi, John K.
AU - Marsh, Stuart E.
N1 - Funding Information:
We would like to thank the Kenya Forestry Research Institute (KEFRI) for logistical support and for availing some of its staff members as field crews. We are especially grateful to Dr. P.K. Konuche, Director KEFRI, David Kamau of the Forest Soils Division, and the field crew including Hamisi Hassan, Wagura Kimondo, Mwaura, and Mohammed Stima. This study would not have been possible without funding from the Rockefeller Foundation African Dissertation Internship Award. We are especially grateful to the anonymous reviewers for their many useful comments and suggestions on improving our manuscript.
PY - 2006/12/1
Y1 - 2006/12/1
N2 - This study used classification and ordination techniques to characterize the composition and distribution of woody vegetation along the Tana River floodplain near Bura in eastern Kenya. Results obtained from cluster analysis of tree and shrub vegetation corroborated the results from non-metric multidimensional scaling (NMS), separating the forests into seven fairly well-defined assemblages of species. The primary vegetation gradient summarized by the ordination was significantly correlated (0.257-0.394, p < 0.01) with soil texture and soil carbon at depths of 50-120 cm. The secondary vegetation gradient was significantly correlated (0.480-0.483, p < 0.01) with indicators of river flood regime. Measured environmental variables, however, only partially explained observed vegetation patterns. Many overstory species were well represented in the regeneration layer of low-lying point-bar and oxbow forests, but were poorly represented in the higher elevation levee forests. There were significant correlations (0.278-0.320, p < 0.01) between the first ordination axis for the regeneration layer and flood regime of the river, and between the second ordination axis and soil texture (0.321-0.346, p < 0.01) in the top 20 cm where seedling roots are likely to be settled. Spirostachys venenifera and Acacia elatior had the widest environmental tolerance, occurring in 78% and 60% of all sample plots, respectively. Populus ilicifolia had the narrowest environmental tolerance, occurring in less than 1% of plots, all located on point-bars.
AB - This study used classification and ordination techniques to characterize the composition and distribution of woody vegetation along the Tana River floodplain near Bura in eastern Kenya. Results obtained from cluster analysis of tree and shrub vegetation corroborated the results from non-metric multidimensional scaling (NMS), separating the forests into seven fairly well-defined assemblages of species. The primary vegetation gradient summarized by the ordination was significantly correlated (0.257-0.394, p < 0.01) with soil texture and soil carbon at depths of 50-120 cm. The secondary vegetation gradient was significantly correlated (0.480-0.483, p < 0.01) with indicators of river flood regime. Measured environmental variables, however, only partially explained observed vegetation patterns. Many overstory species were well represented in the regeneration layer of low-lying point-bar and oxbow forests, but were poorly represented in the higher elevation levee forests. There were significant correlations (0.278-0.320, p < 0.01) between the first ordination axis for the regeneration layer and flood regime of the river, and between the second ordination axis and soil texture (0.321-0.346, p < 0.01) in the top 20 cm where seedling roots are likely to be settled. Spirostachys venenifera and Acacia elatior had the widest environmental tolerance, occurring in 78% and 60% of all sample plots, respectively. Populus ilicifolia had the narrowest environmental tolerance, occurring in less than 1% of plots, all located on point-bars.
KW - Cluster analysis
KW - Diversity
KW - Floodplain
KW - Non-metric multidimensional scaling (NMS)
KW - Riparian
KW - Semi-arid
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U2 - 10.1016/j.foreco.2006.09.006
DO - 10.1016/j.foreco.2006.09.006
M3 - Article
AN - SCOPUS:33751240484
SN - 0378-1127
VL - 236
SP - 211
EP - 228
JO - Forest Ecology and Management
JF - Forest Ecology and Management
IS - 2-3
ER -