Kelly TAN Siang Ting, Life Sciences Major – AY 2014/15
Occurrence of seed dispersers in forest fragments
Deforestation, including that associated with urbanisation, produces huge losses of biodiversity not just by removing habitat for organisms, but also by preventing them from moving among remnant forest patches. This is because the intervening matrix is often impermeable (hostile) to movement of many organisms. Although we don’t tend to think of plants as moving, they do in the sense that they have evolved mechanisms to disperse their seeds.
Some seeds are wind-dispersed (like those of the dipterocarps that dominate most of SE Asia’s rainforests), while others are dispersed by animals (like those of Ficus, or fig, trees that are keystone species in tropical forests around the world). And so, animal seed dispersers play a vital role in ensuring that native plant stocks are well-propagated and, in turn, helping to prevent the establishment of introduced, invasive species.
This is all very relevant in Singapore (SG), which has lost most of its original forest, originally due to agriculture and more recently, to urban development. Today, the matrix consists mainly of urban land cover and the level of fragmentation is high. So, if the matrix is a barrier to animal movement, then this threatens the survival of plants that persist in patches of forest.