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Investigating Forest Gap Makers and Seedling Recruitment on Mangrove Forest Ecosystem, Onne, Rivers State, Port Harcourt

Nnadi P. C., Amadi G. O., Nwiisuator D. S., Benjamin Bameyi Otene

Abstract


The present study investigated forest gap makers and seedlings recruitment in mangrove forest, Onne, Rivers state, Nigeria. The aim of the present study was to examine canopy gap characteristics and their influence on mangrove forest regeneration. The specific objectives were to identify gap makers and the
agents of canopy gap formation in the three mangrove formations, investigate seedling recruitment and growth in forest gap sizes in the three mangrove formations. The present study was conducted in an area of 6 hectares (ha) in the mangrove forest of Onne. About 2 ha each was located randomly across
three zones of the mangrove formation (seaward, middle and land ward). Two transect belts were laid per hectare each in the seaward, middle and land ward zones of the mangrove. Each of the transect belts were 100 m long and 50 m wide and at a distance of 10 m from each other. A total of four transect
belts were laid per zones and 12 transect belts for the present study. Data were collected directly from the field to find canopy gap makers, agents of gap maker’s/mode of death, trees species regeneration through seedling recruitment. A descriptive survey design and a systematic sampling technique were adopted. The findings of the present study were analyzed using descriptive statistics involving percentages and means. The present study revealed that in the mangrove forest of Onne, the agent of canopy gap formation in the study sites include wind, man, and pathogens. The result showed that gap makers in the landward sites were Rhizophora mangle, Avincennia germinans, Lagunculania racemosa, Syzygium guineense litorale, and Conocarpus erectus while that of the seaward and middle were Rhizophora racemosa and Rhizophora harrissonni, respectively. Based on the result of the present study, tree species response to seedling recruitment in canopy gaps could be driven by gap size area and ecological properties within gaps. This implies that canopy gaps play important roles in natural regeneration as well as in the maintenance of ecological diversity in the mangrove forest of Niger Delta, Nigeria.


Keywords


Mangrove, ecosystem, forest gap makers, seedling recruitment, Port Harcourt

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References


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DOI: https://doi.org/10.37591/rrjoe.v12i2.3732

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