ABSTRACT
This work was carried out to determine the floristic composition, abundance and assemblage guild of avifauna in community forests of Ikwuano area of Abia State, Nigeria. Twelve (12) plots measuring 60m x 60m each were mapped in 4 major communities of Ikwuano (Oboro, Ibere, Oloko and Ariam). Within each plot, three line transects measuring 20m x 60m were marked to facilitate access to the terrain. The three transects were then divided into twelve subplots, each measuring 10m x 10m for the purpose of identification and complete enumeration of plant species that attains a minimum height of 16cm and above. Enumerated plant species were tagged to avoid repeated counting of individual species and unknown plant species were collected and identified in the herbarium unit of Forestry and Environmental Management Department, Michael Okpara University of Agriculture, Umudike. A total of eighty nine (89) plant species belonging to forty six (46) families were recorded, of which Dactyladenia barteri had the highest percent relative abundance (8.96%), while Elaeis guineensis and Dialium guineense had 7.01% and 5.68% relative abundance respectively. The following plant families Leguminosae-Pap., Moraceae and Rubiaceae were represented by six (6) plant species, while Apocynaceae, Euphorbiaceae and Malvaceae were represented by four (4) plant species each. Other families were represented by 1 or 3 plant species. Of the 89 plant species recorded, 54 were categorized as Least Concern (LC), 3 Near Threatened (NT), 3 Vulnerable (VU) and 2 Data Deficient (DD) in the IUCN red list of threatened species. Gnetum africana, Irvingia gabonensis, and Milicia excelsa were the NT plant species recorded. Also, Terminalia ivorensis, Nauclea diderrichii, Garcinia sp. were the VU plant species documented in the area. Higher number of plant species diversity were recorded in Ariam, while Oloko had more plant species abundance. Regarding the bird species of the site, aural and visual observation were adopted along the trail of 3 line transects of 20m x 60m of the 60m x 60m main plot with the aid of binoculars for distant birds and mist net for trapping of birds. Photographs of birds caught were taken to validate their occurrence at the site as well as their identification. 25 families comprising of 69 bird species were recorded. Among the documented birds, 46 species were observed within the area, while 23 species were absent during the study but were mentioned in the textual literature referred to. Also, previously unrecorded occurrences of Vidua chalybeata, Euplectes hordeaceus and Ardea melanocephala were documented in Ibere, which were absent from the existing literature at the time of this study. Two (2) bird families (Ardeidae and Accipitridae) of National Conservation interest were recorded in the area. The Ibere community exhibits a higher level of bird species richness and diversity compared to Ariam, Oboro and Oloko. The consensus ecological niche modelling used for variable selection showed that Bende, Isialangwa South, Osisioma Ngwa, Ohafia and Arochukwu possess ecological potentials to support similar species assemblages as those documented in Ikwuano. The study’s findings suggest that Ikwuano should be incorporated into the distribution map of newly documented bird species as a recommended course of action. Continuous monitoring exercise to track changes in bird assemblages over time should be adopted so as to provide valuable information on species population trend. To safeguard, enhance and sustain biodiversity stability, it is recommended to engage the community and carry out habitat enhancement activities, particularly in areas that support species categorized as Vulnerable, Near Threatened and of National Conservation interest.
TABLE
OF CONTENTS
Title
page i
Declaration ii
Certification iii
Dedication iv
Acknowledgements v
Table
of Content vi
List
of Tables vii
List
of Figures viii
List
of Plates ix
Abstract x
CHAPTER 1: INTRODUCTION
1.1 Background of the Study 1
1.2 Statement of Problem 3
1.3 Objectives 4
1.4 Significance of the Study 5
CHAPTER 2: LITERATURE REVIEW
2.1 Brief Description of Flora 6
2.1.1 Vegetation 6
2.1.2 Distribution of tropical plants 7
2.1.2.1 Mangrove
forest 8
2.1.2.2 Freshwater swamp forest 9
2.1.2.3 Riparian forest 9
2.1.2.4 Lowland rainforest 10
2.1.3 Habitat
fragmentation 12
2.2
Species Diversity 12
2.2.1 Plant
diversity 13
2.3
Species-Area Relationships 14
2.3.1 The
habitat diversity hypothesis 15
2.3.2 The area
per se hypothesis 16
2.3.3 The
passive sampling hypothesis 16
2.3.4 The
resource concentration hypothesis 17
2.3.5 Edge effects 17
2.4 Land Use 18
2.5 Avifauna 20
2.5.1 Classification
of avifauna 22
2.5.2 Life cycle of a
bird 23
2.5.2.1
The egg stage 23
2.5.2.2
Hatching stage 23
2.5.2.3 Nestling stage 23
2.5.2.4 Fledgling stage 23
2.5.2.5 Juvenile stage 24
2.5.2.6
Sub adult stage 24
2.5.2.7
Adult stage 24
2.5.3 Avifaunal
diversity in Nigeria 24
2.5.4 Bird species
assemblage 25
2.5.4.1
Flock 25
2.5.4.2
Colony 26
2.5.4.3
Mixed-species foraging flock 26
2.5.4.4
Swarming 26
CHAPTER 3: MATERIALS AND METHOD
3.1 Study Area 21
3.2. Plant species
data collection 30
3.3 Bird
Species Data Collection 32
3.4 Species Distribution Map 33
3.5 Data Analyses 34
3.5.1 Environmental
variables and ecological niche modelling 34
CHAPTER 4: RESULTS AND DISCUSSION
4.1 Results 36
4.1.1 Plant species composition 36
4.1.2 Percent frequency of occurrence of plant
species in the site 40
4.1.3 List of IUCN status of plant species in the
site 43
4.1.4 Plant habit, number of generic and species
composition in the site 45
4.1.5 Bird species composition 46
4.1.6 Bird species caught and photographed during the
study 50
4.1.6.1 Bronze Mannikin (Spermestes cucullatus) 50
4.1.6.2 Adult Female of Yellow-Mantled Widowbird (Euplectes macroura) 52
4.1.6.3 Blue-Spotted Wood Dove (Turtur afer) 53
4.1.6.4 Simple Leaflove (Chlorocichla
simplex) 54
4.1.6.5 Yellow-Rumped Tinkerbird (Pogoniulus bilineatus) 55
4.1.6.6 Grey-Backed Camaroptera (Camaroptera brachyura) 56
4.1.6.7 Magpie Mannikin (Spermestes
fringilloides) 57
4.1.6.8 Black-Winged (Red) Bishop (Euplectes hordeaceus) 58
4.2 Discussion 59
4.2.1 The status of recorded plant species on IUCN
red list of
threatened
species 60
4.2.2 Bird species record and their status on IUCN
red list of
threatened
species 60
4.2.3 Ecological niche modelling 67
CHAPTER 5:
CONCLUSION AND RECOMMENDATION
5.1 Conclusion 70
5.2 Recommendation 71
REFERENCE 73
APPENDICES 84
LIST OF TABLES
4.1: Checklist of Plant Species Composition and
their Percentage Relative
Abundance in the
Study Sites 37
4.2. Percentage
Frequency of Occurrence of Plant Species in the Study Site 41
4.3. Checklist
of IUCN Status of Plant Species in the Study Site 43
4.4. Plant
Habit, Number of Generic and Species Composition 46
4.5 Checklist
of Bird species documented at the site and their IUCN Status 47
4.6.
Bird species richness, diversity, and
evenness across the survey areas 62
LIST OF FIGURES
1. The
rainforest canopy
(Source: Butler, 2006). 11
2. The Species–area curve of vascular
plants. The logarithm
of species
richness is commonly
plotted as a function of
the logarithm of area.
(Source:
Connor and McCoy, 1979). 14
3. Relative effect of major drivers of biodiversity change.
(Source: Sala et al., 2000). 18
4: Framework of potential transitions between land-use/cover states.
(Source: Lambin
and Geist, 2006) 19
5: A
diagram of Bird (Source: Garrigues and Dean, 2014) 21
6. Geologic
map of Abia State showing Ikwuano
(Source:
Amos-Uhegbu et al., 2014) 28
7. Map
showing the bordering communities of the site
(Source:
Amos-Uhegbu et al., 2014) 29
8. Diagram
of field plot layout showing 60m x 60m main plots,
20m x 60m transect plots containing 10m x 10m
subplots. 31
9. The
differences in bird species assemblage in surveyed locations
of Ikwuano LGA 63
10. The differences in bird species identified
based on the different
observation methods in surveyed
locations of Ikwuano LGA. 64
11. The relationship between bird species
richness and plant species
abundance in each surveyed location
of Ikwuano LGA. 65
12. The relationship between bird species
richness and plant species
richness in each surveyed location
of Ikwuano LGA. 66
13. The distribution of potential habitats
with similar to the surveyed
location of Ikwuano LGA based on the
svme Ecological
Niche Prediction algorithm. 68
14. The distribution of potential habitats
with similar to the
surveyed location of Ikwuano LGA
based on the consensus
model of Ecological Niche Prediction
algorithms. 69
LIST OF PLATES
3.1:
A mist net set for the trapping of avifauna species 33
4.1:
Juvenile of Bronze Mannikin (Spermestes
cucullatus) 51
4.2:
Adult Female of Yellow-Mantled Widowbird (Euplectes
macroura) 52
4.3:
Blue-Spotted Wood Dove (Turtur afer)
entrapped in Mist net 53
4.4:
Simple Leaflove (Chlorocichla simplex) 54
4.5:
Yellow-Rumped Tinkerbird (Pogoniulus
bilineatus) 55
4.6:
Grey-Backed Camaroptera (Camaroptera
brachyura) 56
4.7:
Magpie Mannikin (Spermestes fringilloides) 57
4.8:
Black-Winged (Red) Bishop (Euplectes
hordeaceus) 58
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF THE
STUDY
Multitudes of different species of living organisms
are facing much coercion and, as a result, the disappearance of wild plant and
animal diversities is continuously increasing and taking place at an appalling
short-time scale (Novacek and Cleland, 2001). Although, the actual total
diversity of biological species on earth is not yet known (May, 1992).
According to Attiwill (1994) changes in conditions created by disturbances
generate structural and compositional diversities in the forest ecosystem. The
effects of these threats may be insignificant until the affected species
population begin to experience conspicuous decline. According to Pimm et al., 1995 and Brooks et al., 2006, anthropogenic actions are
causing biodiversity crisis, with species extinction rating up to 1000 times
higher than background. Habitat destruction has been reported as one of the
major threats to biodiversity (Myers et
al., 2000; Thomas et al., 2004),
and the diversity of plants, bird and insect species successfully thrive in the
forest ecosystems (Nadkarni, 1994).
The extent of forest habitat as reported by Raf and
Olivier (2011) has continued to decrease due to forest conversion to
agriculture, and land uses associated with urban population growth. Between
1980 and 2000 more than 50 percent of the recent agricultural lands across the
tropics were acquired by clearing intact forests (Raf and Olivier, 2011). The
population pressure has unleashed some notable threats to ecosystems and
biodiversity, which include overexploitation of forest resources, invasion of
alien species, loss of habitat and fragmentation, pollution, global climate
change and disruption of community structures (Chape et al., 2003; Novacek and
Cleland, 2001).
Plant species are one of the major ecological
components of forest. They form the physical structure which comprises of tall
and short plants occupying space in various configurations of tightness or
openness (Patton, 2010). Plant species generally form the vegetation types of
habitat and ecosystem at large. They are known to be the major primary producer
in the food chain, and have other consumers that depend on them for food. There
are indicator plant species used in marking zones as classified by Keay (1959).
Those species are most recurrently encountered in the natural vegetation of the
zones (Isichei, 2015). Plant communities have a substantial influence on the
distribution and interaction of animal species, as they determine the physical
structure of the environment which supports the guild of birds, mammals and
other animal species within the forest (Lawton, 1983). So many authors such as
MacArthur et al., (1962), MacArthur, (1964) and Joshi et al., (2012) have
argued on the determinant of bird species distribution. They reported that, in
determining the bird species diversity, vertical diversity of foliage may be
more crucial than the actual composition of plant species. Bird and habitat
relationship according to Emien (1977), Verner et al., (1986) and Jones et al.,
(1996) may also be determined by vegetation physical-structural variables such
as canopy cover, sizes and height of trees etc.
More so, Wiens and Rotenberry (1981) reported that
locations of higher habitat diversity have the tendency of supporting the
activities of most bird species. Biodiversity assessment of various habitats
has been encouraged and extensively adopted as one of the crucial steps towards
effective management of the environment and its related threats (Olson, et al.,
2001; Oliver and Beattie, 1993). One of the ideal productive approaches for
conserving the variety of life on earth is by identifying places of high
biological diversity (i.e. biological hotspots) and subsequently developing and
implementing management strategies for sustaining and improving the
conservation status of such areas (Ezealor, 2002). Consequently, this study
meant to identify the active areas where plant and bird species under threat
are found in Ikwuano, and attention called for their protection.
1.2
STATEMENT OF PROBLEM
The coverage of forest habitats which are homes to
thousands of plant and animal species has continued to decrease due to
unstoppable conversion of naturally existing forested areas to agricultural
farmlands, and residence for urban population growth by humans (Raf and
Olivier, 2011). This has led to the displacement of the natural inhabitants of
the forest apposite to play important roles in the biosphere transfer of energy
and nutrients.
According to Obi (2002), the loss of biological
diversity in Nigeria has become a serious issue due to their importance in
human’s economic and social activities. Despite the importance of biodiversity,
humans have caused a near destruction of the ecosystem which remains a serious
threat to development and sustainable living (Obi, 2002). When the quality and integrity
of a habitat is compromised, the inhabitant species of the site become
vulnerable to destruction (Gurevitch and Padilla, 2004). Habitat loss is a
major threat to biodiversity species (Henle et
al., 2008), and series of efforts
towards its conservation has continued to progress. A series of conservation
approaches have been adopted to decrease the rate of loss. According to
Ezealor, 2002 the tradition and practices of various cultures in Nigeria
revolve around protection of habitats and species.
Long before now, some communities conserved forests
within their localities with intent for hunting exercise while others
established sacred groves for their idol praise. In some cases, totem and
taboos were used to conserve individual plant and animal species valued for the
purposes of medicine, shade and food. National parks, game reserves and forest
reserves are the organised conservation strategies in Nigeria and in some other
countries. According to Ogunjinmi et al., (2017), the aspiration of a nation
to preserve the flora and fauna as elements of its national and cultural
heritage for the generations unborn is reflected in the establishment of parks.
Human habitation and other activities that affect biodiversity are disallowed
in the conservation area. However, with increase in population pressure and
lack of interest and commitment, these measures are challenged. Consequently,
Ezealor (2002)
reported an approach for biodiversity conservation using bird species as a tool
in Nigeria. According to International Council for Bird Preservation/BirdLife
International (ICBP) (1992) birds are good indicators of the health of the
environment and as well used to predict the distribution and conservation
status of other types of animals and plants.
The paucity of literature on the locations that
accommodate threatened plant and bird species in Ikwuano triggered the quest
for this research. This could be as a result of habitat destruction which may
detract survey attention. Though, patches of isolated forests still exist. This
study will help identify and document areas of plant and bird species of global
interest in order to facilitate their protection and to avoid total loss of the
species.
1.3 OBJECTIVES
The aim of the research is to study the flora composition and assemblage guild of
avian species in community forests of Ikwuano. The specific
objectives included;
i)
to
provide a check
list of the flora and
avifauna
species of Ikwuano,
ii)
to
determine their current global threat status, and
iii)
to
produce species distribution map of locations with related flora and avifauna
composition of the study site in Abia State using ecological niche modelling.
1.4
SIGNIFICANCE OF THE STUDY
Tropical rainforests due to their evergreen vegetative
makeup harbour diversity of species, but deforestation and over-exploitation
encroachments have to some extent reduced their potentials to serve the purpose
of biodiversity reservoirs (Geist and Lambin, 2002). According to Pereira et al.,
(2010) the decline of both plant and animal species in the tropical rainforests
and other ecosystems has become one of the major environmental concerns of 21st
Century. However, monitoring and documentation of the existence and activities
of biodiversity is vital to its conservation (Singh, 2002).
The assessment of biodiversity in an ecosystem is
important in the design and formation of adequate management plan (Richardson,
1999; Verma et al., 2004). Having been considered a good ecological practice as
stated by Onyenweaku et al., (2018) many habitats and species
have been under regular check. This assessment ensures recording of species
which could make known the biotic integrity of the ecosystem (Karr, 1981). Some
scientific authors such as Bibby and Burgess (1992), Roy et al., (2012) reported
that ornithological stock-taking is the most common and simplest practice used
to describe where birds are found. This approach is ideal because birds play
various essential ecological roles in the ecosystem including pollination of
plant species, dispersal of seeds of some plant species, bio-indicator etc.
(Kumbar and Ghadage, 2014). Most tropical forest habitats serve as destination
points for migratory birds (Sanderson et
al., 2006). The locations to which
these migratory species migrate to, need to be identified and efforts made
towards ensuring that the structures which may be the attractant for them are
not destroyed.
Login To Comment