L. villosa is just one of 124 species of Hawaiian lobeliads, a group which makes up a ninth of all Hawaiian plants.
may not be one of the first tools that comes to mind when we think of
conservation strategies, but it should be, as Ania Wieczorek and Carol Oshiro
demonstrate with their recent study of the rare endemic plant Lobelia
villosa. L. villosa only grows in wet forests and mountain bogs between
around 4,000 and 5,000 feet in elevation in Mt. Waialeale and the Alaka‘i
Swamp on the island of Kaua‘i. These plants with long, hairy, purple-tipped
leaves and yellow or greenish flowers are listed as a species of concern by the
U.S. Endangered Species Act of 2006, but the population size is unknown, and
other information about them is limited.
L. villosa is
just one of 124 species of Hawaiian lobeliads, a group which makes up a ninth
of all Hawaiian plants. Interestingly, all lobeliads are thought to have
evolved from a single plant species that made its way to the Islands 13 million
years ago. Since the group was identified, nearly 25 percent of the species
have become extinct, and there are more lobeliad species on U.S. lists of
endangered and threatened species than any other lineage of plants or animals.
Dr. Wieczorek and Ms. Oshiro speculate this could be due to loss of habitat,
small population sizes, non-native animals and plants, and loss of
long-distance pollinators—all problems that are only going to increase for
these and other native plants thanks to climate change, increased invasive
species, and other human impacts.
Carol Oshiro and Dr. Wieczorek also enjoy providing science education to students grades 1-9 through Dr. Wieczorek's popular GENE-ius Day Program.
An important way
to monitor L. villosa and its elusive relatives is through studies of
its genetic variability and the level of gene flow within and between populations.
Such analysis, using microsatellite markers, can show the amount of inbreeding
present in plant colonies, which is a measure of how resilient the species is
to possible environmental and other changes and which can also serve as a way
to measure the population of the plants.
L. villosa shows
moderate diversity, explains Dr. Wieczorek, a researcher in the department of
Tropical Plant and Soil Sciences. This means there’s less inbreeding than in
some other Hawaiian endemic species with similarly restricted distributions.
However, gene flow between plants is limited, a cause for concern. Their study
highlights the need to evaluate long-term genetic impacts on other rare and
endangered Hawaiian plants, as well as to allocate funding to assess recovery
needs and conservation of these unique plants, since changes in factors such as
population size, population fitness, and degree of isolation can be warning
signs that populations are threatened.