Pollinator declines could also have very serious ecological consequences because insect pollination of wild plants is a key supporting mechanism for many other organisms. The dependence of flowering plants on animal (mostly insect) pollination is estimated to range from 78% in temperate regions to 94% in the tropics (Ollerton et al., 2011).
Pollination processes are relatively resilient to loss of species because of ecological characteristics (e.g. behavioural flexibility, species redundancy) that confer robustness (Memmott et al., 2004). However, simulation models indicate that if pollinator extinctions continue unabated then sudden crashes in plant diversity may arise when those species that interact frequently with many others in a network are eliminated (Kaiser-Bunbury et al., 2010). Plants underpin terrestrial ecosystems by forming the base of many food webs. Consequently, reduced abundance and extinction of pollinators would have serious ecological implications not only for individual plant species but also the wider community of organisms associated with plant and pollinator, and ultimately ecosystem function.
These ecological consequences would be particularly felt in tropical regions where much global biodiversity is found and where dependence on animal pollination is high (Ollerton et al., 2011). It is conceivable that such ecological change might impact further on human health as tropical plants are the source of many commercial nutritional supplements and, as yet undiscovered, medicinal properties (Eilers et al., 2011), and also on the availability of non-timber forest products, and other ecosystem services.