BINDURA UNIVERSITY OF SCIENCE EDUCATION

DEPARTMENT OF NATURAL RESOURCES

MIOMBO WOODY VEGETATION STRUCTURE AND COMPOSITION IN

CHINAKIDZWA TAKUDZWA

(B1440620)

A DISSERTATION SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS OF THE BACHELOR OF ENVIRONMENTAL SCIENCE HONOURS DEGREE IN NATURAL RESOURCES MANAGEMENT.

MAY 2018

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RELEASE FORM

Author: Chinakidzwa Takudzwa

Reg Number: B1440620

Degree: Bachelor of Environmental Science Honours Degree in NRM

Project Title: structure and composition in savannas.

Permission is hereby granted to Bindura University of Science Education Library to produce a single copy of this dissertation and lend such copy for private, scholarly or scientific research only.

Signed......

Permanent Address: No. 6129 Unit J Seke Chitungwiza

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APPROVAL FORM

The undersigned certified that they have supervised and recommended to Bindura University of Science Education for acceptance of dissertation entitled “Miombo woodlands structure and composition in savannas”, submitted in partial fulfilment of the Bachelor of Environmental Science Honours Degree in Natural Resources Management.

Name of supervisor: Dr. A. Mureva

Signed ……………………………………………………….

Date: 03 /10/2018

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DEDICATION

I dedicate this work to my family and friends for the unwavering support throughout the research and God Almighty who gave me the strength, health and other resources to successfully accomplish this research.

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ACKNOWLEDGEMENTS

First of all I would like to thank the Lord Almighty for the gift of life and strength in carrying out this study. I would also like to extend my sincere gratitude to my supervisor Dr. Mureva for his invaluable contributions, comments, and help. I am grateful for his patience in supervising my study. My sincere gratitude is extended to my industrial internship supervisor Mr. Chimanikire for his efforts. I also express my sincere thanks to the Bindura Forestry Commission, for their permission and also my friends for their contributions and assistance.I thank my fellow students who contributed by constructive criticism. . Finally I would like to thank my parents for their unwavering support during the entire period I was doing this research.

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ABSTRACT

This study assessed woody vegetation structure and composition in Miombo Woodlands in Zimbabwe that is Mukuvisi Woodlands in Harare, Lilburn Farm in Bindura and Ruzawi Estate in Marondera. Data about woody vegetation structure and composition were collected from 30 randomly placed plots measuring 20 × 30m from all study areas. The information recorded included diameter at breast height, tree height and species name. A total of 66 woody plant species were recorded. Analysis of data was done using SPSS software. Tree density was higher in Ruzawi Estate (813 trees ha-1) than Lilburn Farm (640 trees ha-1) and Mukuvisi Woodlands (531 trees ha-1). Mukuvisi Woodlands had the highest mean height (7.55 ± 0.19m) than Lilburn Farm (6.12 ± 0.12m) and Ruzawi Estate (6.12 ± 0.07m). DBH was highest in Mukuvisi Woodlands (14.51 ± 0.40cm) than Lilburn farm (10.54 ± 0.25cm) and Ruzawi Estate (10.28 ± 0.24). Lilburn Farm had a higher species richness (11.6 ± 1.07) and diversity (H’ = 1.88 ± 0.13) than species richness in Mukuvisi Woodlands (6.5 ± 0.56) and diversity (H’=1.46 ± 0.06) and also species richness in Ruzawi Estate (4.8 ± 0.42) and diversity (H’=0.98 ± 0.13). The DBH distribution of most of the dominant species indicated active recruitment and regeneration in the woodlands. The results of the study suggest that there are variations in woody vegetation structure and composition in Miombo Woodlands in savannas and this can be attributed to both natural and human disturbance factors such as altitude and fires. The study recommends in-depth research to better understand the drivers of woody vegetation structure and composition variations in Miombo woodlands in savannas.

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TABLE OF CONTENT

RELEASE FORM ...... i APPROVAL FORM ...... ii DEDICATION...... iii ACKNOWLEDGEMENTS ...... iv ABSTRACT ...... v LIST OF FIGURES ...... viii LIST OF TABLES ...... ix LIST OF APPENDICES ...... x LIST OF ACRONYMS AND ABBREVIATIONS ...... xi CHAPTER 1: INTRODUCTION ...... 1 1.1 BACKGROUND ...... 1 1.2 PROBLEM STATEMENT ...... 2 1.3 JUSTIFICATION ...... 3 1.3 AIM ...... 3 1.4 OBJECTIVES ...... 3 CHAPTER 2: LITERATURE REVIEW ...... 4 2.1 WOODY VEGETATION STRUCTURE AND COMPOSITION OF MIOMBO WOODLANDS ...... 4 2.1.1 WOODY VEGETATION STRUCTURE IN MIOMBO WOODLANDS ...... 4 2.1.2 WOODY VEGETATION COMPOSITION IN MIOMBO WOODLANDS ...... 6 2.2 FACTORS INFLUENCING WOODY VEGETATION STRUCTURE AND COMPOSITION VARIATIONS IN MIOMBO WOODLANDS ...... 6 CHAPTER 3: METHODOLOGY ...... 10 3.1 DESCRIPTION OF STUDY AREA ...... 10 3.2 STUDY DESIGN ...... 12 3.2.1 SAMPLING PROCEDURE AND DATA COLLECTION ...... 12 3.2.2 DATA ANALYSIS ...... 12 CHAPTER 4: RESULTS ...... 14 4.1 WOODY VEGETATION STRUCTURE AND COMPOSITION IN MUKUVISI WOODLANDS, LILBURN FARM AND RUZAWI ESTATE ...... 14

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4.1.1 WOODY VEGETATION STRUCTURE ...... 15 4.1.2 WOODY VEGETATION COMPOSITION ...... 22 CHAPTER 5: DISCUSSION ...... 24 5.1 WOODY VEGETATION STRUCTURE AND COMPOSITION IN MUKUVISI WOODLANDS, LILBURN FARM AND RUZAWI ESTATE...... 24 5.1.1 WOODY VEGETATION STRUCTURE ...... 24 5.1.2 WOODY VEGETATION COMPOSITION ...... 26 CHAPTER 6: CONCLUSIONS AND RECOMMENDATIONS ...... 30 6.1 CONCLUSIONS ...... 30 6.2 RECOMMENDATIONS ...... 30 REFERENCES ...... 32 APPENDICES ...... 37

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LIST OF FIGURES

Figure 3.1: Map showing location of the study sites; Mukuvisi Woodlands in Harare, Lilburn Farm in Bindura and Ruzawi Estate in Marondera...... 11

Figure 4.1: The mean DBH for the six most common woody species in Mukuvisi Woodlands Lilburn Farm and Ruzawi Estate...... 17

Figure 4.2:The mean heights for the six most common woody species in Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate...... 18

Figure 4.3: The mean canopy diameter for the six most common woody species in Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate...... 19

Figure 4.4: The diameter size-class distribution for the six most common woody species in Mukuvisi Woodlands...... 21

Figure 4.5: The diameter size-class distribution for the six most common woody species in Lilburn Farm...... 22

Figure 4.6: The diameter size-class distribution for the six most common woody species in Ruzawi Estate...... 23

Figure 4.7: Species diversity and species richness across the three study sites of Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate...... 24

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LIST OF TABLES

Table 3.1: Biophysical and physical characteristics of the studied miombo woodlands...... 12

Table 4.1: Summary of woody species composition and structural characteristics of woody species for each miombo in savannas in Zimbabwe (mean ± standard errors)...... 15

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LIST OF APPENDICES

Appendix 1: List of woody species recorded in Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate...... 37

Appendix 2: Post Hoc Tests for Multiple Comparisons for Species Diversity amongst sites…………………………………………………………………………………………...41

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LIST OF ACRONYMS AND ABBREVIATIONS

ASL: Above sea level

DBH: Diameter at Breast Height

GPS: Global Positioning System

Ha-1: Hectare

LSD: Least Significant Difference for Means (5% level)

M3 : Cubic metres

SPSS: Social Statistics for Social Science

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CHAPTER 1: INTRODUCTION

1.1 BACKGROUND

Miombo woodland is major vegetation in most parts of Africa covering an estimated 3.6 million km2 and covers ten countries in Central and East Africa (Thomas et al ., 2014). The word Miombo is vernacular and has been adopted by most ecologists to describe those woodlands dominated by tree species of the genera Brachystegia, Julbernardia and Isoberlinia (Munishi et al., 2010: Giliba et al ., 2011). It is a high biodiversity woodland that provides useful resources to both the rural and urban populations who use a range of goods such as fuel wood, charcoal and non wood forest products such as fibre, fruits and fungi (Thomas et al ., 2014). More than 100 million people are supported by the woodlands as they also offer services such as cultural values and regulation of climate (Syampungani, 2008). Approximately 13 million hectares of forest is cleared annually to provide livelihoods, incomes and employment for people in the tropics and one of the major uses of Miombo woodlands is firewood with households in the region using an estimated 5 to 7 tonnes of dry wood per household per year (Syampungani, 2008). Miombo woodlands area has decreased greatly because of unsustainable practices for instance, in , about 97% of all wood production is consumed in the form of wood fuel which is used in tobacco curing and tobacco farmers use about 1m3 firewood to cure about 57 kilograms of tobacco (Hamza Mgumia, 2017). Average harvestable wood volume in dry miombo ranges from 14m3 per ha-1 in Malawi to 59m3 per ha-1 in Zambia with a maximum value of 117m3 per ha-1 (Mashapa and Gandiwa., 2013). The stand structure and species composition of the woodlands has been created through human intervention, whereby the major form of land use involves cultivation of small fields of sorghum, millet and maize (Mashapa and Gandiwa., 2013). Grazing has also threatened the woodlands, for instance repeated elephant browsing disturbs the normal growth of the woodland due to the top kill effect, they break branches and stems and uproot the woody vegetation species (Zisadza-Gandiwa et al., 2013).

Most studies of miombo woodland have focused on the structure, composition and species diversity in specific areas or localities. According to their study of vegetation structure and composition across different land uses in a semiarid of Southern Zimbabwe,

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Zisadza-Gandiwa et al., (2013) observed significant differences in variables of tree density, tree height, woody species diversity and grass species richness. A protected area had lower species diversity as compared to the adjacent communal area and causes of less diversity of these trees in this area are relatively unknown. It is recommended that there is need for regular monitoring of vegetation structure and composition in all areas surrounding protected areas and not only restricting ecological monitoring effort within the boundaries of protected areas. A study in Bereku Forest Reserve in Tanzania by Giliba et al., (2011) assessed species composition, richness and diversity and species such as Brachystegia spiciformis were dominant and species richness for some timber tree species such as Pterocarpus angolensis was poor due to their exploitation. Despite these findings, the study recommends in-depth forest inventory and preparation of management plan. Long term rather than short term monitoring in woodland composition and structure is necessary and therefore is recommended in order to determine the possible changes over time and institute necessary management practices. Most studies have focused on specific areas or land management areas in a particular region or site. This study aims to determine miombo woody structure and composition in different sites or regions. However, Banda et al ., (2006) studied woody vegetation and composition along a protection gradient in a miombo ecosystem of Western Tanzania. Sampling of trees was done in a national park, game controlled area, forest reserve and an open area. Mean stem density of trees was highest in the game controlled but lower in a national park. In addition, basal area was lower in national park, forest rerserve and open area were significantly lower than game controleed area. This was due to high elephant population in the national park browsing tree recruits.

1.2 PROBLEM STATEMENT

Several studies regarding the structure and composition of miombo woodlands have been conducted in various areas, therefore there is a limited pool of information on the structure and composition of the woodlands, and especially on how they differ in various ecological regions. The origin of the differences of woody vegetation within and between stands or at local level is unclear and may be as a result of several factors which include past history and edaphic factors amongst others. Against this background, assessing the structure and composition of miombo woodlands in various regions could guide current management on woodland management strategies.

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1.3 JUSTIFICATION

The general similarity in the structure and composition of miombo woodlands over large areas implies that the major environmental conditions are extensively and broadly the same over a larger area. It is also important to understand the fact that on a local scale there are some notable differences that can be observed and as a result various factors such as soil moisture, past and present land use among other factors which differ in various areas or regions and modify the structure and composition of the woodlands (Giliba et al., 2011).The likeliness in the appearance of the woodlands is due to the outstandingly similar physiognomy of the main canopy trees (Giliba et al., 2011). Such a study of the stand structure and woody species composition is important in the management of numerous forest resources which may consist of wildlife and aesthetic value and also as a basis for projecting changes in the vegetation over time. It is also vital for the regeneration, growth, mortality, development and spread of various disturbances (Gadow et al., 2012).

Information from this quantitative inventory is important since it provides a valuable reference forest assessment and improves knowledge by the identification of ecologically useful species or those of special importance and concern, leading to the identification of the necessary conservation efforts which lead to sustainability of forest biodiversity. More so, the present study is vital in creating useful baseline data successively leading to the conservation and management of flora and fauna (Naidu and Kumar, 2016).

1.3 AIM

This study aimed at determining Miombo woody vegetation structure and composition in savannas.

1.4 OBJECTIVES

1. To determine the woody vegetation structure in Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate. 2. To determine the woody vegetation composition in Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate.

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CHAPTER 2: LITERATURE REVIEW

2.1 WOODY VEGETATION STRUCTURE AND COMPOSITION OF MIOMBO WOODLANDS

Stand structure and composition are important tools for the management of various forest resources as it gives a detailed description of the forest conditions for wildlife, aesthetics, hydrologic recovery, range of forage conditions and forms basis for foretelling changes in vegetation cover time (Isango, 2007). Woody vegetation structure and composition play an essential part in the functioning of the ecosystems and on how they provide services and these two aspects are influenced by nutrient and water availability, fire, herbivory and pressures from grazing (Zisadza-Gandiwa et al., 2013). The animal community is also structured by the state of woody vegetation structure and composition (Muboko et al., 2013). The stand structure has an effect on aesthetic and recreational values as well as abundance of plant and animal species and it is an essential aspect in the assessment and analysis of the forest ecosystems and indicates overall biodiversity and suitability of habitats (Pastorella and Paletto, 2013). Composition and structure of Miombo Woodlands is moderately similar over large ecological areas, indicating an extensive similarity in the major environmental conditions characterised by high rainfall, average and low rainfall areas, however the differences are more clear at local scale and also the origin of these differences is unclear, however factors such as human disturbances, soil moisture, land use have been some of the major factors considered as the main factors influencing the structure and composition of the woodlands (Giliba et al., 2011). Several studies of stand structure and composition of miombo woodlands have been conducted and there is no enough information on the structure and composition of woody vegetation species and assessing these two aspects help guide on the management of various forest resources and how they change over time (Muboko et al., 2013).

2.1.1 WOODY VEGETATION STRUCTURE IN MIOMBO WOODLANDS

Stand structure refers to the spatial distribution, mutual position and the difference in the diameter and height of trees in a forest ecosystem (Pastorella and Paletto, 2013). It is also described as the spatial arrangement of a range of components of the ecosystem, such as the

4 heights of different canopy levels and the spacing of trees (Gadow et al., 2012). According to Zisadza-Gandiwa et al., (2013), woody vegetation structure in Miombo woodlands is influenced by the available amount of water, nutrients, fire and herbivory typology, grazing pressure as well as the various human activities. The habitat and species diversity are influenced by stand structure and it has an effect on aesthetic and the recreational values and also on the abundance of plant and animal species, it is therefore used as an indicator of the overal biodiversity and suitability of habitat (Pastorella and Paletto, 2013).

An assessment of woody vegetation structure is vital as it provides information pertaining to the spatial distribution of tree species and their dimensions, crown lengths and leaf areas and assessment of these features facilitates a comparison between a forest ecosystem that is managed to that one which is not managed (Gadow et al., 2012). Another important aspect is that the vertical and horizontal distributions of tree sizes establish micro-climatic conditions variations, the availability of resources, habitat resources and the biodiversity within a forest community (Khaine et al., 2017). According to Gadow et al., (2012) information concerning the stand structure leads to an improved know-how of the history, functions and future development potential of a future forest ecosytem.The structure of Miombo wooodlands is by and large the same over large regions due to same environmental conditions , however, differences are more apparent at local scale (Kuyah et al., 2014). Woody plants comprise about 95-98% of the above ground biomass of undisturbed stands and herbaceous species and grasses encompass the remainder (Kachamba, et al., 2016). In the Miombo woodlands of Tanzania, species density are typically 348-1495 stems per hectare for trees with a DBH of greater than 4 centimetres (Backéus et al., 2006). According to Nkonoki and Msuya (2014), the average numbers of stems per hectare for all diameter classes was 567 stems per hectare for undisturbed forest strata in Chenene Forest Reserve in Tanzania and in Bereku Forest Reserve in Tanzania density was 616 stems per hectare for trees with greater than 4 centimetres DBH (Giliba et al., 2011). Tree height appears to be related to moisture availability and soil depth, for instance woody species such as Brachystegia spiciformis and Brachystegia longifolia that grow on deep well drained soils can reach up to 27 metres in wet Miombo woodlands athough in general they may be above 20 metres (Kuyah et al., 2014).. The stand basal area increases linearly with increasing mean annual rainfall, for instance in deep soils in wet miombo woodland the recorded basal area of trees in old-growth, mixed age stands ranges to about 22 square metres per hectare in the Democratic Republic of Congo (Fleig., 2015).

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2.1.2 WOODY VEGETATION COMPOSITION IN MIOMBO WOODLANDS

Vegetation composition describes the floristic characteristics of the vegetation and can be measured by species richness, diversity and evenness (Mashapa and Gandiwa., 2013). Species richness is the total number of species in an area while species evennes is the relative abundance or proportion of individuals among species and species diversity is an index that incorporates both species richness and the relative abundance of species (Shirima et al., 2011). Woody plants comprise 95-98% of above ground biomass of undisturbed stands, whereas the remaining portion comprises of grass and herbaceous species (Sawe et al., 2014). It is estimated that 650 species are contained in the miombo woodland (Lupala et al., 2015). Approximately 8500 species of higher plants are found in the miombo woodland and over 54% are endemic, with 4% being trees (Lupala et al., 2015). Tree species in the genera Brachystegia, Julbernardia and Isoberlinia are the major characteristic of the woodland and other important tree species in the woodland include Pseudolachnostylis maprouneifolia and Burkea africana among others (Mwakalukwa et al., 2014).The structure and composition of miombo woodland differ along the rainfall gradient across the region. The observed structural and compositional differences that follow the rainfall gradient from the drier areas to the wet areas are enough confirmation providing an indication that there is a linkage between rainfall and miombo woodland production (Kachamba et al., 2016). The dominance of tree species in the genera Brachystegia, Julbernardia and Isoberlinia makes the miombo woodland distinct from other African woodlands as they are rarely found outside the miombo woodland. Wet miombo woodlands which include countries such Angola, Northern Zambia and South Western Tanzania receive more than 1000 millimetres of rainfall annually and canopy heights are usually greater than 15 metres due to deep, moist soils (Mashapa and Gandiwa, 2013). In countries that include Zimbabwe, Malawi and where the dry miombo exists annual rainfall received is less than 1000 millimetres and canopy heights usually do not exceed 15 metres (Mashapa and Gandiwa, 2013).

2.2 FACTORS INFLUENCING WOODY VEGETATION STRUCTURE AND COMPOSITION VARIATIONS IN MIOMBO WOODLANDS

The structure of woody vegetation is a result of natural processes and human disturbances (Giliba et al., 2011). Important natural processes are species-specific tree growth mortality and recruitment and natural disturbances such as fire, in addition to the various human related

6 factors which tend to have a significant effect to a large extent (Banda et al ., 2006). According to Gandiwa et al., (2013), factors influencing variations in woody vegetation structure in miombo woodlands are fire, herbivory, rainfall, soil type and human activities.

Muboko et al., (2013) studied the woody vegetation structure and composition in Mapembe Nature Reserve in eastern Zimbabwe characterised by Miombo woodlands. The study was delineated into three different strata comprising of wetland areas, mountainous area and plains, and significant differences were recorded on tree height, tree canopy volume, basal area and canopy diameter. Important similarities were observed in canopy volume, a relatively high tree density and large plant basal area per unit area. Mountains and wetlands strata were heavily affected by high human activities like deforestation hence the significance canopy volume observed, 66.40m3 and 125.50m3 respectively as opposed to the plains which had high tree densities of 153m3. Selective hardwood timber harvesting likely as a source of fuel for tobacco curing and other anthropogenic disturbances may have amplified the dominance of Branchystegia spiciformis and Julbernardia globiflora over all other woody species. Tree height was greatest in the plains with a median range of 6.25 metres and lowest in the mountains where the median range was 5.79 metres. Tree density was greatest in the plains with 1033.33 stems per hectare and lowest in the wetlands (300 stems ha-1). The study revealed that woody vegetation structure is significantly different and composition relatively uniform as there was no significant differences in woody species diversity across the three strata. However the study by Muboko et al., (2013), did not investigate other influential factors such as topography, edaphic and moisture variations.

Backéus et al., (2006) studied tree communities and structural dynamics in miombo woodlands of Tanzania. Tree vegetation and size structure was sampled in a miombo woodland and related to environmental factors, particularly soil and disturbance history. Four plant communities with different woody species were distinguished. The research observed that the differences in size distribution between communities must be more related to disturbance history rather than soil conditions. In one community some woody species had more individuals than expected with a diameter of approximately 35-45cm indicating regular regeneration. The DBH for Julbernardia globiflora, on the other hand, showed a rapid drop above 40cm, indicating earlier clearing or lack of regeneration. According to Backéus et al ., (2006), the higher than expected number of individuals of sizes around 35–50 cm DBH for

7 some miombo species indicates a period with less disturbance , a period of effective fire control or regeneration on former cleared land.

A study was also conducted in western Tanzania which is dominated by Miombo woodlands. The study looked at the structure and composition along a protection gradient of the woodlands in the region. In their study, Banda et al ., (2006), observed basal area, stem density, species richness and unique species in different sites with different levels of conservation, a national park,a game controlled area, a forest reserve and an open access area. Their results showed basal area to be highest in game controlled areas (24m2 ha-1), stem density was high in game controlled area (947 stems ha-1) and forest reserve (453 stems ha-1) and unique species were high in all areas except national parks. Species richness was high in game controlled area and forest reserves and low in national parks and open area. Their measures of forest structure and composition showed that national parks do not essentially conserve the greatest diversity of species and as such other various strategies might be key to the conservation of species in these localities. Their results however were different from the supposition by conservation managers’ view on the total protection of areas to protect biodiversity including plants. They also observed that most protected areas have poor vegetation since protection is geared more towards animals.

In their study of woody species diversity, composition and vegetation structure in a dry forest Miombo woodland at Mazowe botanical reserve Zimudzi et al., (2013), studied relative density, dominance, frequency and species and family importance values were computed to characterize the species composition. Stem density and basal area were also measured. Their results showed that the basal area and stem density were very high in the riverine (70.24m2 ha-1 and 2040 stems ha-1), followed by the anthills (20.74m2 ha-1 and 572 stems ha-1), then the hill (18.58 m2 ha-1 and 764 stems ha-1 ) and lastly the slope areas (12.51 m2 ha-1 and 815 stems ha-1). The results also showed that the average diameter of all individual trees was very high in the hill (10.27cm), almost similar in the slope (8.39 cm) and riverine areas (8.65 cm) and least on the anthills (6.25cm). The DBH were variable throughout the vegetation communities, but generally trees had largest DBH values in the hill area and least values on the anthills. Considerable variability in soil physicochemical properties provides variable micro-habitat for the growth of huge amount of species. Differences in species diversity were observed. The anthills were the most diverse with a Shannon Index value of (3.42), closely followed by the hills (3.31), while the slope was the least diverse (1.85). At Mazowe

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Botanical Reserve it was concluded that the existence of a variety of habitats including anthills, river valleys and streams, hills and slopes had an influence on the structure of vegetation. The species richness was very high and compared well with other similar studies in other Miombo woodlands and this was attributed to the status of the reserve as a protected area with differences in its habitat.

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CHAPTER 3: METHODOLOGY

3.1 DESCRIPTION OF STUDY AREA

The study was conducted in three different sites in the north-eastern miombo woodlands of Zimbabwe (Fig 3.1): a) Mukuvisi Woodlands in Harare; b) Lilburn Farm in Bindura, and; c) Ruzawi Estate in Marondera. The selection of the sites was based on geographical location, management regime and climatic conditions to capture a wide range of vegetation factors.

The study was carried out in three miombo woodlands located in various towns or cities in different provinces of Zimbabwe that is, Harare, Bindura and Marondera. The selected sites were Mukuvisi Woodlands Nature Reserve in Harare, Lilburn Farm in Bindura and Ruzawi Estate in Marondera.

Figure 3.1. Map showing location of the study sites; Mukuvisi Woodlands in Harare, Lilburn Farm in Bindura and Ruzawi Estate in Marondera.

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Mukuvisi Woodlands is a well protected nature reserve that conserves the Miombo woodland and various game species such as zebra (Equus quagga), (Giraffa camelo-pardalis), (Connocaetus taurinus), (Aepyceros melampus), for recreational purposes. Lilburn Farm is a woodland that is state owned, a protected site and wood harvesting is prohibited, however accessibility is easier and open since it is not fenced. Ruzawi Estate in Marondera is private owned and it is a fenced woodland mainly concerned with the conservation of indigenous tree species.

These study sites symbolize the Miombo woodland dominated by the genera Brachystegia and Julbernardia in a relatively flat area at 1100-1700 metres a.s.l. The general climate is bimodal with the rain season in October to May and dry season in June to September. The mean annual rainfall is 500-1000mm and temperature ranges between 16°C and 29°C. The area is dominated by sandy soils. Table 3.1 below shows the biophysical and climatic characteristics of the studied miombo woodlands.

Table 3.1: Biophysical and physical characteristics of the studied miombo woodlands.

Site City/ Town Area Location Altitude Dominan Mean Mean Dominant woody (ha) (m) t soil temp. rain species type (°C) (mm)

17°50'35 S. Sandy loam Mukuvisi 1490- Brachystegia Harare 277 31°5’42 E. 26.0 858 Woodland 1500 soils. spiciformis,

17°20'19S. Sandy Lilburn 1131- Brachystegia Bindura 520 loam 19.4 850 Farm 1177 boehmii 31°17'15E. soils

18°13' 59S. Sandy Ruzawi Maronder 1565- Brachystegia 1221 loam 16.7 902 Estate a 1680 spiciformis, 31° 33'06E. soils

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3.2 STUDY DESIGN

3.2.1 SAMPLING PROCEDURE AND DATA COLLECTION

Composition and structure of woody vegetation was measured in 10 randomly placed sample plots of 20 × 30m in each woodland (Zisadza-Gandiwa et al., 2013). A random sampling unit was established in the field. Random sampling requires that each member of population have an equal chance of being included (Adams and Lawrence, 2015). A total of thirty square plots in all study sites were selected for study that is a total of ten plots in each of the three study sites. The study was done during the dry season for easier identification of species. The GPS was used to take readings of the approximate locations of each of the sample plots by checking the plot co-ordinates. In each sample plot, all woody trees were identified on site and counted. DBH, crown diameter, height, woody species names and GPS readings for each individual within the plot was recorded. The height of woody vegetation was measured by placing a calibrated 8 metre pole against a tree and a visual estimation of height was done for those trees with a height of greater than 8 metres. DBH and crown diameter was measured using a tape measure. All the data were recorded in a spreadsheet.

3.2.2 DATA ANALYSIS

After data collection, computation using Microsoft Excel 2007 was done. Data were analysed using SPSS Statistics Version 20. Descriptive statistics were used to summarize woody vegetation data. LSD Descriptive statistics were conducted using the Simple ANOVA test. Descriptive statistics were also conducted using the Compare Means (Means) and the woody vegetation structure variables were used as the dependent list and the sites and plots were used as the independent list. Means options included were for the mean and the standard error of mean, therefore it was used to test for differences in the means of DBH, species height and crown diameter of all the three sites. Woody plant species diversity for the three miombo woodlands was calculated using the Shannon- Weiner Index. Shannon-Weiner Index was computed to describe species richness and evenness and is mostly used because all species must be represented and it is not affected by sample size (Beatriz et al ., 2012). The value allows us to know the number of species and how the abundance of the species is distributed

12 among all the species in the community (Beatriz et al ., 2012).. The Shannon- Weiner Index was computed using the following formula;

H = ∑ - (Pi * ln Pi)

i=1 where:

H = the Shannon diversity index

Pi = fraction of the entire population made up of species i

S = numbers of species encountered

∑ = sum from species 1 to species S

The power to which the base e (e = 2.718281828...... ) must be raised to obtain a number is called the natural logarithm (ln) of the number.

Presentations of the vertical bar graphs was done using Sigma plot 10.0.

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CHAPTER 4: RESULTS

4.1 WOODY VEGETATION STRUCTURE AND COMPOSITION IN MUKUVISI WOODLANDS, LILBURN FARM AND RUZAWI ESTATE

A total of 1191 woody plants representing 66 woody species were recorded in the 30 sample plots. The complete list of species recorded is given in Appendix 1. A total of 319 woody plants belonging to 31 species were recorded in Mukuvisi Woodlands, 384 woody plants belonging to 43 species were recorded in Lilburn Farm and 488 woody plants belonging to 17 species were recorded in Ruzawi Estate. Brachystegia spiciformis was the dominant species in all sites and other dominant species in all sites included species such as Julbernardia globiflora, Dichrostachys cinerea, Burkea africana and Uapaca kirkiana. In Mukuvisi Woodlands and Ruzawi Estate the dominant species were Brachystegia spiciformis whereas Brachystegia boehmii was the dominant species in Lilburn Farm. Table 4.1 shows the characteristics of the woody species in the three sites.

Table 4.1. Summary of species composition and structural characteristics of woody species for each miombo woodland in savannas in Zimbabwe (mean ± standard errors).

Woody Species Variable Mukuvisi Woodlands Lilburn Farm Ruzawi Estate

Number of species 31 43 17

Stem density/ ha-1 531.67±7.02 a 640±13.25 b 813.33±17.06 b

Dbh (cm) 14.51 ± 0.40 b 10.54± 0.25 a 10.28 ± 0.24 a

Mean height (m) 7.55 ± 0.19 bc 6.12 ± 0.12 a 6.12 ± 0.07 a

Mean crown diameter (m) 6.50 ± 0.170 bc 7.32 ± 0.23 a 7.04 ± 0.14 a

Shannon index 1.46 ± 0.06c 1.88 ± 0.13c 0.98 ± 0.13 a

Richness 6.5 ± 0.56 a 11.6 ± 1.07 b 4.8 ± 0.42 b

Means without common superscripts column wise are significantly different

14

4.1.1 WOODY VEGETATION STRUCTURE

Significant differences were recorded on tree density in miombo woodlands across the studied sites. Lilburn Farm had a higher (P<0.001) stem density than Mukuvisi Woodlands. Significant differences in DBH were recorded. The DBH of trees from Mukuvisi Woodlands was higher (P< 0.001) as compared to Lilburn Farm. Also, Mukuvisi DBH was high (P< 0.001) as compared to Ruzawi Estate. Lilburn Farm DBH was high (P=0.35) as compared to Ruzawi Estate however there was no significant difference in DBH between Lilburn Farm and Ruzawi Estate. The tree height of Mukuvisi Woodlands was higher (P<0.001) as compared to Lilburn Farm. Mukuvisi Woodlands tree height was also higher (P<0.001) as compared to Ruzawi Estate. There was no significant difference in the mean height of Lilburn Farm and Ruzawi Estate (P=0.069). There was a significant difference in the crown diameter of Mukuvisi Woodlands and Lilburn Farm. The canopy diameter of Mukuvisi Woodlands was lower (P<0.001) as compared to Lilburn Farm. The canopy diameter of Mukuvisi Woodlands was also higher (P<0.001) as compared to Ruzawi Estate. There was no significant difference (P=0.152) in the crown diameter of Lilburn Farm and Ruzawi Estate.

Figure 4.1, below show the mean DBH of the six common or dominant woody species in each of the sites of Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate. Six species were considered per woodland because they occurred frequently in each of the study sites. Figure 4.2, below show the mean tree height of the six common or dominant woody species in each of the sites of Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate. Figure 4.3, below show the mean crown diameter of the six common or dominant woody species in each of the sites of Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate.

15

a) Mukuvisi Woodlands b) Lilburn Farm 25 16

14 20 12

15 10

8

DBH (cm) 10 DBH (cm) 6

4 5 2

0 0

Ficus ingens Uapaca kirkiana Uapaca kirkiana Parinari curatellifolia Julbernardia globiflora Dichrostachys cinerea Brachystegia boehmii Pterocarpus angolensis Julbernardia globiflora Dichrostachys cinerea Brachystegia spiciformis Brachystegia spiciformis Woody species Woody species

c) Ruzawi Estate

12

10

8

6

DBH (cm) 4

2

0

Rhus longipes Uapaca kirkiana Albizia antunesiana Julbernardia globiflora Brachystegia spiciformisTerminalia stenostachya

Woody species

16

Fig 4.1. The mean DBH for the six most common woody species in Mukuvisi Woodlands Lilburn Farm and Ruzawi Estate.

a) Mukuvisi Woodlands b)Lilburn Farm

12 7

6 10

5 8 4 6 3

Height (m)

Height (m) 4 2

2 1

0 0

Ficus ingens Uapaca kirkiana Uapaca kirkiana Parinari curatellifolia Brachystegia boehmii Julbernardia globiflora Dichrostachys cinerea Julbernardia globiflora Dichrostachys cinerea Brachystegia spiciformis Pterocarpus angolensis Brachystegia spiciformis

Woody species Woody species

c) Ruzawi Estate 8

6

4

Height (m)

2

0

Rhus longipes Uapaca kirkiana Albizia antunesiana Julbernardia globiflora Brachystegia spiciformisTerminalia stenostachya Woody species

17

Fig 4.2. The mean heights for the six most common woody species in Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate.

a) Mukuvisi Woodlands b) Lilburn Farm 12 10

10 8

8

6 6

4 4

Crown diameter

Crown diameter (m) 2 2

0 0

Ficus ingens Uapaca kirkiana Uapaca kirkiana Parinari curatellifolia Julbernardia globiflora DichrostachysBrachystegia cinerea boehmii Julbernardia globiflora Dichrostachys cinerea Brachystegia spiciformis Brachystegia spiciformis Pterocarpus angolensis

Woody species Woody species

c) Ruzawi Estate 10

8

6

4

Crown diameter (m) 2

0

Rhus longipes Uapaca kirkiana Albizia antunesiana Julbernardia globiflora Brachystegia spiciformisTerminalia stenostachya Woody species

18

Fig 4.3. The mean canopy diameter for the six most common woody species in Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate.

The diameter class of the six common tree species in each site are presented in Fig 4.4, 4.5 and 4.6. Six species were used per woodland because they occurred frequently in each of the study sites. The diameter class distribution of the dominant tree species in each of the study sites produced “J” shaped curves, reverse “J” shaped curves as well as a skewed bell shaped (unimodal) curves.

Most woody species in Mukuvisi Woodlands produced a unimodal curve (Fig 4.4).The 0-5 dbh class was poorly represented in all the sites. Most were in the 0-10, 15-20, 20-25 dbh classes and no individuals reached >35cm. Likewise, in all the other two sites no individuals reached >35cm.Tree species of Uapaca kirkiana, Pterocarpus angolensis, Julbernardia globiflora and Brachsytegia spiciformis were not represented in the 5-10 dbh classes (Fig 4.4).

In Lilburn Farm, most species produced reverse “J” shaped curves. The 0-5 dbh class was only represented by Brachsytegia spiciformis, and the diameter class distribution of this species produced a unimodal curve whereas the rest produced reverse “J” shaped curves (Fig 4.5). Ruzawi Estate also produced species with reverse “J” shaped curves except for that of Rhus longipes which produced a “J” shaped curve and that of Julbernardia globiflora which produced a unimodal curve (Fig 4.6).

19

Parinari curatellifolia Uapaca kirkiana Pterocarpus angolensis 10 14 6 12 8 5 10 6 4 8 3 4 6

Frequency

Frequency 4 Frequency 2 2 2 1 0 0 0 0-5 0-5 5-10 5-10 0-5 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 5-10 10-1515-2020-2525-3030-35 Size class- dbh (cm) Size class- dbh (cm) Size class- dbh (cm)

Dichrostachys cinerea Julbernardia globiflora Brachystegia spiciformis 30 12 40

25 10 30 20 8

15 6 20

Frequency 10 Frequency 4 Frequency 10 5 2

0 0 0

0-5 0-5 0-5 5-10 5-10 5-10 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 Size class- dbh (cm) Size class -dbh (cm) Size class- dbh (cm)

Fig 4.4. The diameter size-class distribution for the six most common woody species in Mukuvisi Woodlands

20

Ficus ingens Uapaca kirkiana Julbernardia globiflora 12 12 14

10 10 12 10 8 8 8 6 6 6

Frequency 4 Frequency 4 Frequency 4 2 2 2 0 0 0

0-5 0-5 0-5 5-10 5-10 5-10 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 Size class- dbh (cm) Size class- dbh (cm) Size class- dbh (cm)

Brachystegia boehmii 25 Brachystegia spiciformis 14 Dichrostachys cinerea 120 12 100 20 10 80 15 8 60 10 6

Frequency

Frequency 40 Frequency 4 5 2 20 0 0 0

0-5 0-5 0-5 5-10 5-10 5-10 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 Size class -dbh (cm) Size class- dbh (cm) Size class- dbh (cm)

Fig 4.5. The diameter size-class distribution for the six most common woody species in Lilburn Farm.

21

Rhus longipes Terminalia stenostachya Uapaca kirkiana 8 3.5 70 3.0 60 6 2.5 50 2.0 40 4 1.5 30

Frequency

Frequency 2 1.0 Frequency 20 0.5 10 0 0.0 0

0-5 0-5 0-5 5-10 5-10 5-10 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35

Size class- dbh (cm) Size class- dbh (cm) Size class- dbh (cm)

Brachystegia spiciformis Julbernardia globiflora 180 60 2.5 Albizia antunesiana 160 140 50 2.0 120 40 100 1.5 80 30 1.0

Frequency 60 Frequency 20 Frequency 40 0.5 20 10 0 0 0.0 0-5 5-10 0-5 0-5 10-1515-2020-2525-3030-35 5-10 5-10 10-1515-2020-2525-3030-35 10-1515-2020-2525-3030-35 Size class-dbh (cm) Size class-dbh (cm) Size class- dbh (cm)

Fig 4.6. The diameter size-class distribution for the six most common woody species in Ruzawi Estate.

4.1.2 WOODY VEGETATION COMPOSITION

The Shannon- Wiener’s index (H′) (Table 4.1) indicated that Lilburn Farm was the most diverse (1.88) followed by Mukuvisi Woodlands (1.46) while Ruzawi Estate (0. 98) was the least diverse woodland. Mukuvisi Woodlands had a lower (P=0.33) (H′) value than Lilburn Farm but had a high (P=0.14) (H′) as compared to Ruzawi Estate. Lilburn Farm had a high (P<0.001) (H′) value as compared to Ruzawi Estate (Fig 4.7a). Mukuvisi Woodlands had a lower (P< 0.001) species richness as compared to Lilburn Farm. Mukuvisi Woodlands was also high (P=0.250) in species richness as compared to Ruzawi Estate. Lilburn Farm had a high P<0.001 species richness than Ruzawi Estate. There was no significant difference in species richness between Mukuvisi Woodlands and Ruzawi Estate (Fig 4.7b).

22

a) Shannon-Weiner Diversity Index b) Species Richness value

2.5 20

2.0 15

1.5

10 1.0

Shannon value

Richness value 5 0.5

0.0 0

Lilburn Farm Lilburn Farm Ruzawi Estate Ruzawi Estate Site Site Mukuvisi Woodlands Mukuvisi Woodlands

Fig 4.7. Species diversity and species richness across the three study sites of Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate.

23

CHAPTER 5: DISCUSSION

5.1 WOODY VEGETATION STRUCTURE AND COMPOSITION IN MUKUVISI WOODLANDS, LILBURN FARM AND RUZAWI ESTATE.

The three miombo woodlands examined in this study showed significant differences in structural and compositional attributes. The differences in the structure and composition can be attributed to natural factors and also to anthropogenic factors. Factors such as geology, edaphic factors especially soil nutrients and moisture, herbivory, past and present land use and other anthropogenic factors are known to influence structure and composition of miombo woodlands (Gonçalves et al., 2017).

5.1.1 WOODY VEGETATION STRUCTURE

Tree densities in the different woodlands ranged from 530-814 stems per ha-1 and this range compares well with studies that have been done in other study areas for instance in Mazowe Botanical Reserve in Zimbabwe. According to Zimudzi et al., (2013), stem densities in Mazowe Botanical Reserve in Zimbabwe ranged between 570-2040 stems per ha-1 and according to a study conducted by Banda et al ., (2006) who studied woody vegetation and composition along a protection gradient in a miombo ecosystem of Western Tanzania stem densities ranged between 320-720 stems per ha-1 .Tree densities could have differed due to the effects that include fires and strict protection status. A higher tree density in Ruzawi Estate as compared to the other two sites can be attributed to the past human disturbance that is the human removal of mature woody plants and fires that used to be frequent in the estate. This could have promoted resprouting of new offshoots leading to high tree density.

This is the same case in Lilburn Farm in Bindura where relatively higher tree density could be as a result of human disturbance due to easy access despite being recognised as a protected area where tree cutting is illegal. According to Zisadza-Gandiwa et al., (2013) human removal of mature woody plants in Manjinji Pan Important Bird Area for domestic use is likely to have promoted increased resprouting which led to high tree density , therefore

24 density increased due to the dual recruitment from the coppice of cut trees and suppressed saplings. Despite the strict protection status in Mukuvisi Woodlands which prevents exploitation of wood resources and the presence of high soil moisture content, the expectation was that tree density would have been very high as compared to the other sites however the lower tree density could be attributed to elevation which is relatively lower than that of Ruzawi Estate.. According to a study conducted in the Miombo ecosystem in Lake Rukwa Basin in Southern Tanzania by Munishi et al., (2010) elevation and percent slope were proved to be among factors that determine plant community patterns. Based on the analysis miombo woodland which is associated with species such as Julbernardia globiflora and Brachystegia spiciformis are found on high elevation areas and Brachystegia boehmii- Pericopsis angolensis woodland are found on mid elevation areas. This explains the abundance of Brachystegia boehmii in Lilburn Farm in Bindura than in Mukuvisi Woodlands and Ruzawi Estate where Brachystegia spiciformis is more dominant. Mukuvisi Woodlands had a higher average tree height as compared to that of Lilburn Farm and Ruzawi Estate. Mukuvisi Woodlands is a nature reserve and woody species are protected from human effects. Besides that, the game species that are dominant for instance and kudus are grazers and do not cause massive damage to the tree species. High soil moisture content due to the presence of rivers could have promoted tree growth. Edaphic factors, principally soil moisture and soil nutrients are reported by (Forest and Showa, 2014) as having sound effects on patterns of vegetation in plant communities. On the other hand, lower tree height and crown diameter in Lilburn Farm and Ruzawi Estate could be as a result of disturbance through selective harvesting for timber and possibly due to frequent fires especially in Ruzawi Estate, According to Muboko et al., (2013) human disturbances and encroachments into protected areas , for instance poaching of wood in Mukuvisi Woodlands in Harare have influenced woodland dynamics at different spatial levels across the savanna in Africa.

The diameter class distribution of dominant trees in all of the miombo woodlands produced reverse “J” shaped curves (Fig 4.4; 4.5; 4.6) and unimodal curves. The inverse “J” shaped distribution of DBH classes showing more trees in the juvenile classes indicates that the population in these miombo woodlands is healthy and expanding. The young trees will likely recruit into adult size classes. Regeneration is characterized by seed production, seed dispersal, seedling germination, survival and growth and the regeneration and population structure of a given vegetation community are influenced by prevailing environmental conditions at the time of seed release (Kanungwe et al., 2013). Recruitment is the

25 regeneration and population status of vegetation communities and refers to the transition of individuals from one growth stage to another and population and regeneration structures can be stable or unstable (Rocky and Mligo, 2012). Species present in all sites such as Uapaca kirkiana, Brachystegia spiciformis and Burkea africana showed a reverse “J” shaped size class distribution in all sites therefore indicating a stable population with most individuals in the lower DBH class and few individuals in the higher classes. This might suggest that they have high rates of germination but low recruitment. According to a study conducted by Zimudzi et al., (2013) in Mazowe Botanical Reserve active regeneration and recruitment in Miombo woodland was observed indicating a good indication of sustainability of the reserve as a result of the healthy and expanding population. However, not all of the germinated seedlings are recruited into the larger size classes as some die due to browsing. Seed dispersal is an important component in tree population structure distribution It allows seeds to reach suitable micro sites for germination and establishment (Everard et al., 1995). In Mukuvisi Woodlands for instance, species such as Pterocarpus angolensis, Parinari curatellifolia and Julbernardia globiflora produced population size-class distributions which were bell shaped with fewer individuals in the lower and higher DBH classes than in the middle classes. This indicates an unstable population. High numbers of individuals in the middle classes could be due to an interrupted recruitment event that could have occurred when the conditions were favourable. This can be as a result of differences in reproductive strategy, competition, hydrology and disturbance from fires (Nangendo et al ., 2006). The majority of sampled population had structures indicating on-going recruitment. There was no significant difference between sites in terms of recruitment and woody vegetation species showed spatial variation in their population size structure between different study sites.

5.1.2 WOODY VEGETATION COMPOSITION

The highest biodiversity in Lilburn Farm could be attributed to the nature and qualities of the physical landscape in the area whereby the vegetation species respond distinctively to the opportunities and limitations that are as a result of the chemical and physical features of the landscape. The responses are more pronounced on mountain ecosystems (Munishi et al., 2010). Lilburn Farm occurs on a mountainous area and sudden changes in altitude, slope, aspect moisture gradients, hydrology, temperature and rainfall contribute to a higher diversity and high species richness. The woodland stretches from the mountain, along steep slopes,

26 shallow trenches and on flat slopes towards the western end. A relatively medium diversity index of 1.46 in Mukuvisi Woodlands could be attributed to the protection status of the area and differences in habitat and soil characteristics. A diversity of habitats such as Mukuvisi and Chiraura Rivers that cut across the woodland, anthills, slopes exist at the woodland as well as variability in soil physiochemical properties which provide rough micro-habitats which lead to the growth of huge number of species. According to Mwakalukwa et al., (2014) these factors influence the growth of biodiversity for instance termite mounds are nutrient and rich in minerals such as nitrogen, carbon, calcium, magnesium, potassium and phosphorous , contain high moisture as well as organic matter. The low diversity and species richness of (0.98) in Ruzawi Estate is mainly due to the dominance of the species Brachystegia spiciformis and Julbernardia globiflora and human activities for instance heavy illegal cutting down of tree species for firewood or for construction and frequent occurrence of veld fires. Selective timber harvesting likely as a source of fuel for tobacco curing and other anthropogenic disturbances may strengthen the dominance of Brachystegia spiciformis and Julbernardia globiflora species over all other species (Muboko et al., 2013). Human pressure has influenced the woody vegetation structure and composition of several terrestrial ecosystems (Kachamba et al., 2016).

27

CHAPTER 6: CONCLUSIONS AND RECOMMENDATIONS

6.1 CONCLUSIONS

The results of the study indicated that there were significant differences in the structural and compositional attributes of vegetation in the three miombo woodlands. Ruzawi Estate was the most abundant site due to active regeneration and recruitment whereas in Mukuvisi Woodlands tree density was determined by low elevation. Tree heights in Mukuvisi Woodlands were highest due to the presence of high soil moisture content whereas in Lilburn Farm and Ruzawi Estate, human disturbance played a huge role. Higher crown diameter in Ruzawi Estate and Mukuvisi Woodlands can be attributed to resprouting after disturbance. However; this finding suggests that recruitment and regeneration have influenced stem density in all woodlands indicating a healthy growing population of species. Higher species diversity and species richness in Lilburn Farm is attributed to the physical landscape of the area and in Mukuvisi Woodlands the presence of a diversity of habitats contributes to higher species diversity and richness. However human activities in particular veld fires and illegal cutting down of trees have contributed to low species richness and diversity in Ruzawi Estate. Variation in woody vegetation structure and composition could therefore be attributed to both natural and anthropogenic factors.

6.2 RECOMMENDATIONS

Assessing the structure and composition of miombo woodlands in various regions is important could guide current management on woodland management strategies but there is need for further woodland inventory in creating useful baseline data sequentially leading to the conservation and management of flora and fauna.

 There is need for regular monitoring of woody vegetation structure and composition in various areas and not restricting ecological monitoring effort within localised areas.  There is need for further studies to ascertain other factors influencing structure and

30 composition of miombo woodlands for instance altitude in savannas.

31

REFERENCES

Adams, K. and Lawrence, E. (2015). Research Methods, Statistics and Applications. California: SAGE Publications Inc.

Backéus, I., Pettersson, B., Strömquist, L., and Ruffo, C. (2006). Tree communities and structural dynamics in miombo (Brachystegia-Julbernardia) woodland, Tanzania. Forest Ecology and Management, 230(1–3), 171–178. https://doi.org/10.1016/j.foreco.2006.04.033

Banda, T., Schwartz, M. W., and Caro, T. (2006). Woody vegetation structure and composition along a protection gradient in a miombo ecosystem of western Tanzania. Forest Ecology and Management , 230, 179–185. https://doi.org/10.1016/j.foreco.2006.04.032.

Beatriz, H., Evangelista, A., Thomaz, S. M., and Roberto, L. (2012). Comparison of Diversity Indices Applied to Macrophyte Incidence-Based Data Comparison of Diversity Indices Applied to Macrophyte Incidence-Based Data. Brazilian Archives of Biology and Technology, 55 (2), 277-288 . https://doi.org/10.1590/S1516-89132012000200014.

Everard, D. A., Midgley, J. J., and Wyk, G. F. Van. (1995). Dynamics of some forests in Kwa Zulu-Natal, South Africa, based on ordinations and size-class distributions. South African Journal of Botany, 61(6), 283–292. https://doi.org/10.1016/S0254-6299(15)30548-2.

Fleig, F. D. (2015). Diversity and Structure of Miombo Woodlands in Mozambique Using a Range of Sampling Sizes. Journal of Agricultural Science and Technology ,5, 679–690. https://doi.org/10.17265/2161-6264/2015.10.005.

Forest, M., and Showa, W. (2014). Floristic composition , diversity and vegetation structure of woody plant communities in Boda dry evergreen Montane Forest. International Journal of Biodiversity and Conservation, 6(May), 382–391. https://doi.org/10.5897/IJBC2014.0703.

Gadow, K., Zhang, C. Y., Wehenkel, C., Pommerening, A., Corral-rivas, J., Korol, M., … Zhao, X. H. (2012). A survey on species diversity, abundance and community structure of woody plants in Gobeya Rural Administrative of Tehundele District, Ethiopia. Forest Structure and Diversity, 6 (5), 382-391 https://doi.org/10.1007/978-94-007-2202-6.

32

Gandiwa, P., Chinoitezvi, E., and Gandiwa, E. (2013). Structure and composition of woody vegetation in two important bird areas in southern Zimbabwe, The Journal of Animal and Plant Sciences, 23(3), 813–820.

Giliba, R. A., Boon, E. K., Kayombo, C. J., Musamba, E. B., Kashindye, A. M., and Shayo, P. F. (2011). Species composition, richness and diversity in miombo woodland of Bereku forest reserve, Tanzania. Journal of Biodiversity, 2(1), 1–7.

Gonçalves, F. M. P., Revermann, R., Gomes, A. L., Aidar, M. P. M., Finckh, M., and Juergens, N. (2017). Tree Species Diversity and Composition of Miombo Woodlands in

South-Central Angola : A Chronosequence of Forest Recovery after Shifting Cultivation.

International Journal of Forestry Research, 2017, 14.

Hamza Mgumia, F. (2017). Traditional Uses of Miombo Woodland Tree Species in Sikonge District, Tanzania. International Journal of Natural Resource Ecology and Management, 2(4), 69.

Isango, J. A. (2007). Stand Structure and Tree Species Composition of Tanzania Miombo Woodlands : A Case Study from Miombo Woodlands of Community Based Forest Management in Iringa District. Management of Indigenous Tree Species for Ecosystem Restoration and Wood Production in Semi-Arid Miombo Woodlands in Eastern Africa, 50 (February), 43–56.

Kachamba, D. J., Eid, T., and Gobakken, T. (2016). Above- and Belowground Biomass Models for Trees in the Miombo Woodlands of Malawi. Journal of Forest Ecology, 6 (3), 22- 37. https://doi.org/10.3390/f7020038.

Kanungwe, F., Helen, C., John, A., and Vinya, R. (2013). Forest Ecology and Management Floristic composition , species diversity and carbon storage in charcoal and agriculture fallows and management implications in Miombo woodlands of Zambia. Forest Ecology and Management, 304, 99–109. https://doi.org/10.1016/j.foreco.2013.04.024.

Khaine, I., Woo, S. Y., Kang, H., Kwak, M., Je, S. M., You, H., … Kim, J. (2017). Species

33

Diversity , Stand Structure , and Species Distribution across a Precipitation Gradient in Tropical Forests in Myanmar. Journal of Forests, 66, 1–15. https://doi.org/10.3390/f8080282.

Kuyah, S., Sileshi, G. W., Njoloma, J., Mng’omba, S., and Neufeldt, H. (2014). Estimating aboveground tree biomass in three different miombo woodlands and associated land use systems in Malawi. Biomass and Bioenergy, 66, 214–222. https://doi.org/10.1016/j.biombioe.2014.02.005.

Lupala, Z. J., Lusambo, L. P., Ngaga, Y. M., and Makatta, A. A. (2015). The Land Use and Cover Change in Miombo Woodlands under Community Based Forest Management and Its Implication to Climate Change Mitigation : A Case of Southern Highlands of Tanzania. International Journal of Forestry Research, 2015, 17.

Mashapa, C., and Gandiwa, E. (2013). Woody vegetation structure and composition in Makomo Nature Reserve , Eastern Zimbabwe. Journal of Applied Sciences and

Environmental Management , 19 (3), 420-437

Muboko, Never; Mushonga, Marvellous R.; Chibuwe, Nunurai; Mashapa, Clayton; Gandiwa, E. (2013). Woody vegetation structure and composition in Mapembe Nature Reserve , eastern Zimbabwe. Journal of Applied Sciences and Environmental Management, 17(4), 475–481.

Munishi, P. K. T., Mringi, S., Shirima, D. D., and Linda, S. K. (2010). The role of the Miombo Woodlands of the Southern Highlands of Tanzania as carbon sinks. Forest Ecology and Management 2(12), 261–269.

Mwakalukwa, E. E., Meilby, H., and Treue, T. (2014). Floristic Composition , Structure , and Species Associations of Dry Miombo Woodland in Tanzania. Journal of North-East African Biodiversity, 2014(2).

Naidu, M. T., and Kumar, O. A. (2016). Journal of Asia-Paci fi c Biodiversity Tree diversity , stand structure , and community composition of tropical forests in Eastern Ghats of Andhra Pradesh , India. Journal of Asia-Pacific Biodiversity, 9(3), 328–334. https://doi.org/10.1016/j.japb.2016.03.019.

34

Nangendo, G., Steege, H. T. E. R., and Bongers, F. (2006). Composition of woody species in a dynamic forest – woodland – savannah mosaic in Uganda : implications for conservation and management. Journal of Biodiversity and Conservation, 2006, 1467–1495. https://doi.org/10.1007/s10531-005-1876.

Nkonoki, J. B., and Msuya, S. M. (2014). Effect of Anthropogenic Activities in Dry Miombo Woodlands on Wood Stock and Tree Diversity : A Case of Chenene Forest Reserve , Bahi , Tanzania. International Journal of Innovation and Scientific Research, 7(1), 69–77.

Pastorella, F., and Paletto, A. (2013). Stand structure indices as tools to support forest management : an application in Trentino forests ( Italy ). Journal of Forest Science, 2013(4), 159–168.

Rocky, J., and Mligo, C. (2012). Regeneration pattern and size-class distribution of indigenous woody species in exotic plantation in Pugu Forest Reserve, Tanzania. International Journal of Biodiversity and Conservation, 4(1), 1–14. 28 ref. https://doi.org/10.5897/IJBC11.198.

Sawe, T. C., Munishi, P. K. T., and Maliondo, S. M. (2014). Woodlands degradation in the Southern Highlands , Miombo of Tanzania : Implications on conservation and carbon stocks. International Journal of Biodiversity and Conservation 6(3), 230–237. https://doi.org/10.5897/IJBC2013.0671.

Shirima, D. D., Munishi, P. K. T., Lewis, S. L., Burgess, N. D., Marshall, A. R., Balmford, A., … Zahabu, E. M. (2011). Carbon storage , structure and composition of miombo woodlands in Tanzania ’ s Eastern Arc Mountains. African Journal of Ecology, 49 (3), 332– 342.

Syampungani, S. (2008). Opportunities and challenges for sustainable management of miombo woodlands: the Zambian perspective. Working Papers of the Finnish Forest Research Institute, 98, 125–130.

Thomas, C. S., Pantaleo, K. T. M., and Salim, M. M. (2014). Woodlands degradation in the

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Southern Highlands, Miombo of Tanzania: Implications on conservation and carbon stocks. International Journal of Biodiversity and Conservation, 6, (3) , 230–237.

Zimudzi, C., Mapaura, A., Chapano, C., and Duri, W. (2013). Woody species composition , structure and diversity of Mazowe Botanical Reserve , Zimbabwe. Journal of Biodiversity and Environmental Sciences, 3(6), 17–29.

Zisadza-gandiwa, P., Mango, L., Gandiwa, E., Goza, D., Chinoitezvi, E., Shimbani, J., and Muvengwi, J. (2013). Variation in woody vegetation structure and composition in a semi-arid savanna of Southern Zimbabwe. International Journal of Biodiversity and Conservation, 5(2), 71–77. https://doi.org/10.5897/IJBC12.095.

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APPENDICES

Appendix 1. List of woody species recorded in Mukuvisi Woodlands, Lilburn Farm and Ruzawi Estate.

SCIENTIFIC NAME COMMON NAME MUKUVISI LILBURN RUZAWI WOODLANDS FARM ESTATE 1 Adenia gummifera Snake-climber √ × × 2 Albizia antunesiana Peacock flower × × √ 3 Bauhinia galpinii Red bauhinia × √ × 4 Bauhinia urbaniana Perlebia urbaniana × √ × 5 Brachystegia boehmii Prince of wales × √ × feathers 6 Brachystegia Msasa √ √ √ spiciformis 7 Bridelia micrantha Mitzeerie × √ × 8 Burkea africana Red syringa √ √ √ 9 Cassia abbreviata Long-tail cassia × √ × 10 Catha edulis Khat × × √ 11 Celtis africana White stinkwood × √ × 12 Celtis sinensis Chinese hackberry × √ × 13 Combretum molle Velvet bush willow, × √ √ 14 Cussonia arborea Octopus cabbage × √ × tree 15 Cussonia natalensis Rock cabbage tree × √ √ 16 Cussonia spicata Cabbage tree × √ × 17 Dichrostachys cinerea Chinese-lanterns √ √ √

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18 Diospyros lycioides Red star apple √ × × 19 Diospyros Jackalberry × √ × mespiliformis 20 Dombeya rotundifolia Wild- pear √ × × 21 Dovialis caffra Kei apple × √ × 22 Dovyalis zeyheri Apricot sourberry × √ × 23 Erythrina abyssinica Lucky-bean tree × √ × 24 Euclea divinorum Magic guarri × √ × 25 Ficus burkei Common wild fig √ × × 26 Ficus ingens Red leaved fig √ √ × 27 Ficus sur Broom-cluster fig √ √ × 28 Ficus sycomorus Sycomore fig √ √ × 29 Flacourtia indica Governors-plum √ × × 30 Grewia flavescens Donkeyberry √ × × 31 Grewia occidentalis Button-wood × √ × 32 Julbernardia Munondo √ √ √ globiflora 33 Kirkia acuminata Kirkia √ × × 34 Lannea stuhlmannii False marula × √ × 35 Lannea discolor Live long × × √ 36 Lonchocarpus Apple-leaf × √ × capassa 37 Maytenus Confetti tree × √ × senegalensis 38 Ozoroa reticulata Raisin bush × √ √ 39 Parinari curatellifolia Mobola-plum √ √ ×

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40 Peltoforum African weeping × √ × africanum cattle 41 Pittosporum Cheesewood × × √ viridiflorum 42 Protea gaguedi African protea × × √ 43 Pseudolachnostylis Duiker-berry √ √ × maprouneifolia 44 Pterocarpus Mukwa √ × × angolensis 45 Rhus lancea African sumac × √ × 46 Rhus longipes Large-leaved rhus × × √ 47 Schotia brachypetala Weeping boerbean √ × × 48 Strychnos cocculoides Corky-bark monkey × × √ orange 49 Strychnos spinosa Monkey orange √ × √ 50 Syzygium cordatum Waterberry √ √ × 51 Syzygium guineense Woodland × √ × waterberry 52 Terminalia Rosette Cluster-leaf × × √ stenostachya 53 Trema orientalis Pigeonwood √ × × 54 Uapaca kirkiana Sugar plum √ √ √ 55 Vachellia abyssinica Nyanga flat-top √ × × 56 Vachellia caffra Common hook-thorn × √ × 57 Vachellia galpinii Monkey thorn √ √ × 58 Vachellia karoo Sweet thorn √ × × 59 Vachellia nilotica Scented-thorn × √ × 60 Vachellia sieberiana Paperbark thorn √ × ×

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61 Vachellia tortilis Umbrella thorn √ × × 62 Vangueria infausta Wild- medlar × √ √ 63 Vangueriopsis False wild medlar √ × × lanciflora 64 Ximenia americana Yellow plum × √ × 65 Ximenia caffra Sourplum × √ × 66 Ziziphus mucronata Buffalo-thorn × √ ×

KEY

× - absent in site

√ - present in site

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Appendix 2.

Post Hoc Tests SITE

Multiple Comparisons Tukey HSD Dependent Variable (I) SITE (J) SITE Mean Difference Std. Error Sig. 95% Confidence Interval (I-J) Lower Bound Upper Bound SITE 2 -5.10000000* 1.041722221 .000 -7.68286450 -2.51713550 SITE 1 SITE 3 1.70000000 1.041722221 .250 -.88286450 4.28286450 SITE 1 5.10000000* 1.041722221 .000 2.51713550 7.68286450 RICHNESS SITE 2 SITE 3 6.80000000* 1.041722221 .000 4.21713550 9.38286450 SITE 1 -1.70000000 1.041722221 .250 -4.28286450 .88286450 SITE 3 SITE 2 -6.80000000* 1.041722221 .000 -9.38286450 -4.21713550 SITE 2 -.42055270* .157965876 .033 -.81221609 -.02888931 SITE 1 SITE 3 .48000390* .157965876 .014 .08834051 .87166729 SITE 1 .42055270* .157965876 .033 .02888931 .81221609 SHANNON SITE 2 SITE 3 .90055660* .157965876 .000 .50889321 1.29221999 SITE 1 -.48000390* .157965876 .014 -.87166729 -.08834051 SITE 3 SITE 2 -.90055660* .157965876 .000 -1.29221999 -.50889321 SITE 2 .05683960 .066717131 .675 -.10858003 .22225923 SITE 1 SITE 3 -.17260700* .066717131 .040 -.33802663 -.00718737 SITE 1 -.05683960 .066717131 .675 -.22225923 .10858003 SIMPSON D SITE 2 SITE 3 -.22944660* .066717131 .005 -.39486623 -.06402697 SITE 1 .17260700* .066717131 .040 .00718737 .33802663 SITE 3 SITE 2 .22944660* .066717131 .005 .06402697 .39486623 SITE 2 .16154760 .069434325 .069 -.01060909 .33370429 SITE 1 SITE 3 .02821010 .069434325 .913 -.14394659 .20036679 SITE 1 -.16154760 .069434325 .069 -.33370429 .01060909 SIMPSON E SITE 2 SITE 3 -.13333750 .069434325 .152 -.30549419 .03881919 SITE 1 -.02821010 .069434325 .913 -.20036679 .14394659 SITE 3 SITE 2 .13333750 .069434325 .152 -.03881919 .30549419

Based on observed means. The error term is Mean Square(Error) = .024. *. The mean difference is significant at the .05 level.

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