A recent study of the South Australian donkey orchid (Diuris orientis) has shown that our changing climate is already affecting this species. TREND researcher Fran McGillivray recorded when this species currently flowers in the wild and compared this with the collection dates of herbarium specimens and photographic records dated between 1897 and 2005. This comparison showed that this species of orchid is now flowering 16 days earlier than 98 years ago.
Donkey orchids have evolved to look like and flower at the same time as native pea species to trick native bees in to pollinating them. Changes in flowering may have a flow on effect to pollinators and other plants they pollinate, and could impact on the way in which the orchids breed and hybridise. Orchids are very specialised to their habitat, which suggests that they likely to be some of the most sensitive plants to climate change. Similar changes in the flowering of other plants which are less specialised (including other native vegetation and food crops) are likely to be seen in the future.
Flowering times can have great impacts on how plants grow, animal pollinators, and when applied to agriculture, our food production. For example, if similar trends are seen in cereal crops like wheat, this could reduce the growing season substantially, reducing the amount of food we can produce. Flowering times can also strongly impact the quality of fruits such as grapes, which could lead to reduced wine quality – or give opportunities to grow new varieties in our climate.
The full study is published in Herbarium Collections and Photographic Images: Alternative Data Sources for Phenological Research in the recently published book Phenological Research: Methods for Environmental and Climate Change Analysis. An online copy is available here:
More information on donkey orchids is available here.