CHAPTER ONE

1.0         INTRODUCTION

1.1         Background

The total forest area in the world is about 4 billion hectares (FRA, 2010) with the tropical forests covering about 10 % of the earth surface (Lewis, 2006). The diversity of the tropical forest provides resources which are both tangible and intangible (Antwi, 1999) and these could be considered as ecological, environmental, cultural and socio-economic benefits (Abeney, 1999). In Ghana, the forestry sector contributes about 6 % to the GDP, accounts for 11 % of export earnings, employs a labour force of 100, 000 people, and it provides and supports livelihoods of about 2.5 million rural folks (FAO, 2002; FOSA, 2002).

Records reveal an 8.5 % increase in the rate of tropical deforestation from the 1990’s to the period of 2000 – 2005 (Butler, 2009). Reports by the 2010 Global Forests Resources Assessment indicates a 2 % annual forest loss from 1990 – 2000 in Ghana (FRA, 2010). Forests in Ghana are being depleted at an alarming rate through several factors including excessive logging, mining and quarrying, developmental projects, charcoal production & firewood collection, bushfires, and unsustainable agricultural practices (FAO, 2000).

The impact of human activities on the environment is evident throughout the world and it includes remarkable changes in species composition, abundance, and diversity of organisms in various ecosystems including the tropical forest such as the Tano Offin GSBA (FRA, 2010; Kim

&    Byrne, 2006). Thus information on the current state of the Tano Offin GSBA is vital in 1

maintaining healthy plant diversity which should results in enhanced productivity of the forest, greater prospects for economic development, medical discoveries and an increased resiliency to environmental challenges (Shah, 2009).

1.2          Problem Statement

The deforestation of tropical forest threatens the sustainability of its biodiversity, demanding the conservation of remnant species of flora lest these may be subjected to extinction in the near future (Myers et al., 2000). But how can the plant diversity of tropical forest be conserved if knowledge on the composition and abundance of the different kinds of species is lacking? In this regard, floristic assessment of the forest is indispensable in detecting the risk of extinction, arrival of invasive species and changes in plant diversity over time.

Relatively, limited work has been done in determining the floristic composition and structure of forests in Ghana (Hall & Swaine, 1981; Hawthorne, 1993; Vordzogbe et al., 2005; Anning et al., 2008; Addo-Fordjour et al., 2009b; Pappoe et al., 2010). In 1981, an extensive assessment of the distribution of vascular plants in Ghanaian forests was carried out by Hall and Swaine which included the Tano Offin Forest Reserve (Hall & Swaine, 1981). It has been decades now and thus the need to generate a carefully compiled up-to-date data on the floral composition of the reserve. Moreso, inventories by the Forestry Commission of Ghana in the reserve have focused mainly on timber species (Affum-Baffoe pers.comm) which is deficient for conservation purposes. Most imperatively on the GSBA, records indicate that no formal ecological research has been undertaken in the GSBA (FC, 2007; Affum-Baffoe pers.comm).

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Notably, although 44.5 % of the reserve has been designated as a Globally Significant Biodiversity Area (GSBA), reports about the reserve and even the GSBA indicate activities of illegal logging and other forms of human disturbances (FC, 2007). The situation is that serious to the extent that when the then Minister of Lands and Natural Resources payed an unannounced visit to the Tano Offin Forest Reserve in May 2011, some illegal chainsaw operators were caught right on the act (The Chronicle, 2011).

Depending on the level and rate of infliction, disturbances such as logging in forest affect the composition, structure and light availability to the forest, eventually influencing natural regeneration process (Jennings et al., 1999; Hale, 2004). In addition, canopy opening promotes growth of invasive species which alter the course of natural regeneration in the forest, restraining the resurgence of native trees (Vermeulen & Koziell 2002). Moreover, the Tano Offin GSBA has been a forest reserve of bauxite deposits which presents a potential threat to its forest diversity.

In addition, elevation acts as an important source of local variation and it determines rate of recovering, recruitment and eventually the floristic composition of a forest (Wang et al., 2002; FAO, 2002; Joseph et al., 2012). Thus, investigations on the influence of elevation on patterns of plant diversity is critical for this biodiversity rich area which sits on a mountainous range of the Nyinahin hills – Tano Offin forest reserve is cited as one of the three Upland Evergreen forests in Ghana (Hall & Swaine, 1981). A study with a focus on local patterns of plant diversity assists profoundly with local conservation practices and the management of localised biodiversity patterns (Kim & Bryne, 2006).

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