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9: Floral and faunal diversity


Materials and methods
Results and other observations
Other observations
Discussion
Conclusion
References


Lewis Enu-Kwesi

This paper presents the results of a preliminary inventory of floral diversity and, to a lesser extent, faunal diversity in selected sites within the southern sector of the forest-savanna transition zone in Ghana (see fig. 5.1, p. 39).


Materials and methods

Using principally the rapid multidisciplinary integrated transect survey method described in chapter 6, the following sites were surveyed:

A 30 m traverse chain was dragged along each selected traverse farm footpath extending 1.7 to 2.0 km in distance in each of the study areas. The 30 m chain drag along the footpath was used for the rough-and-ready measurement of the 30 x 30 m2 quadrats within which the plant species (including trees, shrubs, herbs, climbers and geophytes) were rapidly surveyed, identified and recorded as far as one could see on the right-hand side of the transect direction.


Results and other observations

Over 102 plant species belonging to approximately 51 plant families were encountered in the three study areas (tables 9.1, 9.2). Twenty-three families out of the 51 possessed tree species. Eighteen of these 23 families were dicotyledonous and consisted of 34 genera, whereas there were 5 monocotyledonous families that comprised 8 genera. Twenty-eight families out of the 51 also contained herbs, climbers and shrubs, and 23 out of these 28 families were dicotyledonous, whereas the remaining 5 were monocotyledonous. The 28 families consisted of 60 genera, 48 of which were dicotyledonous and 12 monocotyledonous.

Table 9.1 List of Tree Families Encountered in the Three Study Sites

Family Genus, species Dicot./monocot. Lifeform
Agavaceae Dracaena arborea Monocot. t
Anacardiaceae Anacardium occidentale Dicot. t
Mangifera indica Dicot. T/t
Annonaceae Annona sp. Dicot. t
Apocynaceae Alstonia boonei Dicot. T/t
Tabernaemontana glandulosa Dicot. T/t
Rauvolfia vomitoria Dicot. t
Bignoniaceae Newbouldia laevis Dicot. t
Bombacaceae Bombax buonopozense Dicot. T
Ceiba pentandra Dicot. T
Adansonia digitata Dicot. T
Caesalpiniaceae Caesalpinia pulcherrima Dicot. t
Cassia occidentalis Dicot. H
Cassiasiamea Dicot. T/t
Dialium guineense Dicot. t
Combretaceae Terrninalia ivorensis Dicot. T
Euphorbiaceae Alchornea cordifolia Dicot. t
Bridelia micrantha Dicot. t
Hura crepitans Dicot. t
Jatropha curcas Dicot. s
Gramineae Bambusa vulgaris Monocot. t
Labiatae Hoslundia opposita Dicot. s
Lauraceae Persia americana Dicot. t
Moraceae Antiaris toxicaria/africana Dicot. T
Ficus exasperata Dicot. t
Musanga cecropioides Dicot. t
Malvaceae Gossypium arboreum Dicot. s
Mimosaceae Entada africana Dicot. t
Leucaena glauca Dicot. t
Parkia clappertoniana Dicot. t
Musaceae Musa sapientum Monocot. t/H
Meliaceae Azadirachta indica Dicot. T/t
Moraceae Chlorophora/Milicia excelsa Dicot. T
Palmae Cocos nucifera Monocot. t
Elaeis guineensis Monocot. T/t
Papilionaceae Milletia thoningii Dicot. t
Baphianitida Dicot. t
Rubiaceae Morinda lucida Dicot. t
Rutaceae Citrus sinensis Dicot. t/s
Sapotaceae Chrysophyllum albidum Dicot. T/t
Sterculiaceae Cola Bigantea Dicot. T
Theabroma cacao Dicot. s/t
Triplochiton scleroxylon Dicot. T
Tiliaceae Glyphaeabrevis Dicot. t/s
Grewiamalacocarpa Dicot. s
Verbenaceae Vitexdoniane Dicot. t/s

T = large tree capable of exceeding s = shrub or pygmy tree
30 m height (megaphanerophyte) H = herb
t = small tree

Table 9.2 List of Families Eneountered in the Three Study Sites That Contained Shrubs and Herbs

Family Genus, species Dicot./monocot. Life-form
Aeanthaceae Asystasia calycina Dieot. H
Bignoniaeeae Spathodea campanulata Dicot. T
Cannaceae Canna indica Monocot. H
Cueurbitaeeae Coccinia grandis Dicot. e/H
Commelinaceae Commclina capitula Monocot. H
Caesalpiniaeeae Griffonia simplicifolia Dicot. c
Combretaceae Combretum aphanopetalum Dicot. c
Compositae Acanthospermum hispidum Dicot. H
Ageratum conyzoides Dicot. H
Aspilia africana Dicot. H
Bidens pilosa Dicot. H
Chromolaena odorata Dicot. H
Lactuca taraxacifolia Dicot. H
Tridax procumbens Dicot. H
Convolvulaceae Impomoea muricata Dicot. c/H
Cyperaceae Cyperus rotundus Monocot. H
Mariscus ligularis Monocot. H
Euphorbiaceae Euphorbia hirta Dicot. H
Phyllanthus pentandrus Dicot. H
Ricinus communis Dicot. H
Securinega virosa Dicot. s
Gramineae Andropogon africans Monocot. H
Digitaria diagonalis Monocot. H
Eleusine indica Monocot. H
lmperata cylindrica Monocot. H
Panicum maximum Monocot. H
Paspalum orbiculare Monocot. H
Phragmites australis Monocot. H
Sporobolus pyramidalis Monocot. H
Liliaeeae Gloriosa superba Monocot. g/c
Malvaceae Abutilon mauritianum Dicot. H
Gossypium arboreum Dicot. s
Sida acuta Dicot. H
Mimosaceae Mimosa pudica Dicot. H
Shrankia leptocarpa Dicot. H
Nyctaginaceae Mirabilis jalapa Dicot. H
Papilionaceae Arachis hypogea Dicot. H
Centrosema pubescens Dicot. H
Desmodium trifolium Dicot. H
Peuraria phaseoloides Dicot. H
Trifolium repens Dicot. H
Portulacaeeae Talinum triangulare Dicot. H
Solanaceae Datura suaveolens Dicot. H
Schwenkia americana Dicot. H
Solanum torvum Dicot. H
Scrophulariaceae Scoparia dulcis Dieot. H
Sapotaeeae Chrysophyllum albidum Dieot. T/t
Sapindaceae Allophyllus africanus Dicot. c
Paullinia pinnata Dicot. c
Sterculiaceae Waltheria indica Dicot. H
Tiliaceae Triumfetta rhomboidea Dicot. H
Urticaceae Urtica aestuans Dicot. H
Verbenaceae Clerodendron umbellatum Dicot. H
Lantana camara Dicot. H
Starchytarphetta indica Dicot. H
Vitex doniane Dicot. H
Zingiberaceae Costus engleranus Monocot. H

T = large tree capable of exceeding c = small understorey climber
30 m ht. (megaphanerophyte) s = shrub or pygmy tree
t = small tree H = herb

Further analysis of tables 9.1 and 9.2 indicated that when the three study areas were considered together, there was a predominance of herbaceous and shrub species over tree species; and that tall trees (T) that are above 30 m in height constituted the life-form that was least prevalent in the entire study area.

Table 9.3 indicates that there were relatively very few tall trees or megaphanerophytes in the three study areas. These included Bombax buanopozense found at Yensiso, Osonson and Sekesua; Ceiba pentandra also found in all the study areas (Yensiso, Kokormu, Adenya, Osonson, Sekesua and Whanabenya except Amanase). This observation may only indicate that Ceiba pentandra occurs less frequently at Amanase when compared to the other sites and not necessarily that it is totally absent from there. Also Terminalia ivorensis, a good timber species, was found at both Yensiso and Amanase. Antiaris toxicaria/africana was another tree species which was present in all the study areas except at Kokormu and Adenya in the Yensiso area and Whanabenya in the Amanase area. This observation may also simply be an indication of the relative abundance of the species in the three study areas of the transition zone. However, borne as it is out of a preliminary rapid survey, this conclusion must be accepted only as a tentative one to be subjected to verification through more detailed studies.

Other tall tree species that were found included the following very important class one timber species:

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