Chapter one
Introduction
1.1 Introduction:
Biological diversity has become one of the most popular topics recently for discussion both in scientific and political forum at local, national, regional and global level. Floral diversity is the total variability of plant communities. The number of species in a community is important ecologically since the species diversity seems to increase as the community becomes stable .Biodiversity is the variability of plant, animal and microorganism in an ecosystem. Bangladesh is rich in plant diversity includes 86 species of timber plants, 130 fiber-yielding plants, 500 medicinal plants and 29 orchids However, the loss of diversity is distinct due to population pressure, rapid urbanization and illicit felling of tree Bangladesh has a total land area of 14.39 million hectares, of which 9.12 million ha is cultivated, 2.14 million ha public forests, 0.27 million ha village groves and 1.64 million ha constantly under water. The remaining land area (1.22 million hectares) is occupied by tea gardens, uncultivable areas, rural and urban houses and ponds.
The Tilagarh Eco-park is located at North Sylhet Range-1 in Sylhet Forest Division under tropical evergreen and semi-evergreen biogeographic zone. It is about 6 km from Sylhet city. The Eco- Park is established through Gazette Notification No. PA BA MA / PA RI SHA-1/ Tilagarh Eco-park /4/ 2006 /234. After the convention of Biological Diversity, Government of Bangladesh has taken a strategy to conserve the biological diversity of the country by providing protection adequately (Al-amin et al., 2004). Government of Bangladesh decided a target to create protected areas, which will be 10% of the total reserve forest by the year 2015. This is may be due to the commitments with different international organizations and conventions. Due to these commitments, Tilagarh Eco-park declared as an Eco- park recently (2006).
Measuring biodiversity of a community or habitat has been one of the central issues of ecology and conservation (Verghes and Menon, 1997) as to develop biodiversity sustainably, one has to know the species present in an ecosystem, their interdependence and causes of their disturbance (Verma et al., 1999). There is little quantitative information available on the composition and structure of vegetation of Tilagarh Eco-park. Thus the study is an initiative to assess the diversity of tree species composition and quantitative distribution of tree species in this Eco-park.
1.2 Objectives
The Objectives of the study are the following:
- To find out the tree composition of the area.
- To assess the present stock of the tree species and percent distribution of individual species in different diameter and height classes
- To determine the quantitative structure and tree species diversity.
- To introduce every one about Tilagarh Eco-park
