Many species of the plant genus Saussurea are valued by herbalists for their medicinal uses. Although the plants have been being used in traditional Chinese medicine for hundreds of years, research has recently confirmed that their use for medicinal uses were not whimsical. Saussurea lappa for instance, has anti-inflamatory properties and anti-viral potential, while Saussurea eopygmaea and Saussurea medusa have anti-tumor activity. Saussurea medusa and Saussurea laniceps, both commonly known as "Snow Lotus", are harvested at altitudes of 3-4,000 meters by herbal doctors and others seeking the flowers. The flowers are used as therapies for blood disorders, high blood pressure, fertility and menstruation problems. Generally the flowers are thought to be most effective when they are harvested right before they go to seed, which prevents the seeds of these select flowers from being dispersed.
Researchers Jan Salick and Wayne Law published a study forthcoming in Proceedings of the National Academies of Science (PNAS) that reporting that the selective harvesting of the Saussurea laniceps by humans has caused a reduction in the size of the flowers in harvested regions compared to flowers in unharvested regions. They also found that specimens in flower collections over the past century are much larger than what is currently being sold in shops. On the other hand, the species Saussurea medusa, with a purple flower that is apparently less desired, has not decreased in size. The background and purpose for the study are described here.
Researchers have known for years that the habits of harvesters could impact the evolution of species. The phenomena was previously been seen in fish populations that are heavily fished, activity that causes genetic adaptations in response to harvest. The greatest adaptation is a decrease in the average size and very slow recovery of population numbers, though sometimes the headline news belies this reality.
We commonly hear about endangered species as a result of the loss of habitat due to human population development and encroachment, or environmental warming trends. The authors say that the impact of selective harvesting of the prime species specimens, and the potential direct impact on species evolution are also important to consider.
