Results (
Thai) 1:
[Copy]Copied!
Semi-domesticated tree species in agroforestry systems frequently maintain high levels of intra-specific diversity (Dawsonet al., 2013) and research on temperate trees indicates that high genetic variation helps support ecosystem functions (Whitham et al., 2006). When out-crossing indigenous trees exist only at very low densities in farmland, however, as is often the case when they are remnants from natural forest otherwise cleared for crop planting (Lengkeek et al., 2005), they are vulnerable to the absence of neighbours in the landscape to support pollination, reducing the opportunities for reproduction and potentially leading to lower seed set and inbreeding depression (Lowe et al., 2005). This is a particular concern for trees that provide fruit for human consumption, as no cross-pollination/the absence of fruit set may meanthere is no reason for farmers to retain these trees in the agricultural landscape (Dawson et al., 2009). In the worst case scenario, rare, isolated trees in farm landscapes may be the ‘living dead’ (sensu Janzen, 1986; i.e., unable to pollinate and set seed) and willonly survive for the current generation.
Being translated, please wait..