Biologicaldiversity has been defined by Convention on Biological Diversity (1992) as “thevariability among living organisms from all sources including, inter alia, terrestrial,marine and other aquatic ecosystems and the ecological complexes of which theyare part: this includes diversity within species, between species and ofecosystems.
” It is estimated that over a half of the known terrestrial floraand fauna species live in forests (Millenium Ecosystem Assesment, 2005). However, the areacovered by natural forests globally is declining due to severe deforestationand forest degradation, mostly attributed to conversion to agriculture (Brockerhoff et al., 2008).
Interestingly though, plantation forest (defined by FAO(2006) as “forests established through planting or seeding of one or moreindigenous or introduced tree species in the process of afforestation orreforestation”) cover is increasing annually by approximately 3.6 millionhectares (FAO, 2015). Most plantation forests are established primarily forwood and pulp production and a majority often consist of exotic species (Lindenmayer, 2003). In terms of biodiversityconservation, is not disputed that natural/native forests are superior to plantationforests due to their habitat diversity and complexity (Armstrong and vanHensbergen, 1996). However, to effectively analyze the impact of plantation forestson biodiversity conservation, Brockerhoff etal., 2008 suggest that consideration of plantation tree species inquestion; plantation management objectives and land use before plantationestablishment should be done.
Scientists largely agree that tree plantations cancontribute to biodiversity conservation when appropriately managed in line withconservation objectives. For example, in areas where forest degradation and/orfragmentation has occurred, plantation forests play a role in acceleratingforest succession by influencing understory microclimates and soil physicalproperties that have a direct bearing on natural regeneration (Brockerhoff et al., 2008). Besides, tree plantationswhen located in the vicinity of native fragments (matrix), contribute tobiodiversity conservation by: (1) providing an alternative shelter and sourceof livelihood to species whose habitats have been lost (Wunderle, 1997); (2)providing connectivity between forest remnants hence facilitating dispersal (Hampsonand Peterken 1998); and (3) acting as buffers against extreme conditionsthereby facilitating survival of remnant species (Denyer et al.,2006).
Plantation forests also contribute to biodiversity conservation byproviding an alternative source of resources such as timber, thereby savingnatural forests from being over-exploited, subsequently conserving biodiversityin the natural forests (Shepherd, 1993).