Why Tibetan poppies have the blues
Studying the impact of humans on Meconopsis
PhD student Hongyan Xie is passionate about the flora, fauna and unique culture of her native Tibet. Her current research focuses on an exceptionally beautiful genus of poppy known as Meconopsis. Among these is the famous blue poppy, but different species grow a range of striking colours including yellow, red and purple. These poppies grow in the thin air of the alpine regions of Tibet and are amongst the highest growing flowering plants on earth. However the fragile ecosystem that supports Meconopsis is under threat from three different directions.
Climate change is beginning to increase temperatures in many alpine regions of the world. The stark reality of this was underlined by a recent decision by European banks not to offer development loans to lower altitude ski resorts in the Alps, for fear that there would be no more snow. In the case of Meconopsis, the problem is that with increasing temperatures, competitor species are able to colonise its habitat. The poppies can’t easily move to higher altitudes because the soil, rainfall and other environmental factors are different. An area that has been too high to support plant life for hundreds of thousands of years has very much less organic matter in the soil than a vegetated area. In the course of evolution, plants can accommodate such factors but not on the short time scale of the current changes.
The second threat to the poppies is their value in traditional Tibetan medicine. Meconopsis in combination with other local herbs is used to treat inflammation and to assist in the healing of fractures. In addition to local needs, traditional Tibetan medicine is becoming increasingly popular in China. This has raised the market price of the plants, which encourages locals to supplement their incomes by gathering poppies whilst out on the mountains tending their yaks. Unfortunately, Meconopsis is extremely difficult to cultivate and to date, efforts to grow them in commercial quantities have proved unsuccessful. As a result, all medicinal plants must come from specimens collected in the wild.
The third threat to Meconopsis comes from increasing human population, which in turn leads to more yaks and heavier grazing. Although yaks don’t eat the poppies directly, they do displace smaller grazing animals into areas where the poppies grow. More humans also means more picking and more demand for medicine.
Establishing whether or not these three pressures on the poppies are causing their numbers to decline is a matter of careful survey work. But establishing the root cause of such declines is a lot more complicated. Hongyan came to Australia to learn more about plant biology and conservation; she found the expertise she needed in ANU School of Botany and Zoology, and CSIRO Entomology.
Through the course of her studies, Hongyan hopes to fill in many of the sketchy details of the life cycle of various species of Meconopsis. Of special interest is the mechanism of pollination. The study region is a centre of diversity for bumble bees, which are well suited to higher altitude environments. In the short warm part of a summer day in the mountains bumble bees can be seen busily moving from flower to flower, their furry bodies coated with pollen. In the cool of the afternoon hoverflies settle down inside the poppy flowers where they shelter for the night. As they fly off in the warm of the following day they too can be pollinators. It seems that a large part of the reward for pollination in this case is the provision of shelter from the cold of the alpine night.
Ironically, one of the first major contributions to come from this study has been a discovery in entomology. During the course of collecting samples of pollinating insects, Hongyan found a previously unreported species of hoverfly. After consulting with experts at CSIRO and the Smithsonian Institute in the USA, the fly was declared a new species and as its finder, Hongyan was given the honour of naming it. Arctophila khamensis after the region of Tibet it inhabits.
Whilst the Meconopsis poppies are beautiful and economically important in themselves, their plight is linked to that of many other plants and animals in the area including the newly discovered Arctophila khamensis. Hongyan explains, “You can think of Meconopsis as an indicator species. It’s charismatic and people care about it, but what happens to Meconopsis will also affect what happens to other species that may be less visible and less attractive, but are just as vital to the complex webs that form an ecosystem.