The Herbarium’s Role in Climate Change, Conservation Policies

Posted in Science on December 29 2009, by Plant Talk

Barbara Thiers, Ph.D., is Director of the William and Lynda Steere Herbarium and oversees the C.V. Starr Virtual Herbarium.

Part 3 in a 3-part series
Read Part 1 and Part 2

During the past 15 years, my staff and I have devoted a great deal of effort in the creation of the C.V. Starr Virtual Herbarium, which is an on-line catalog of the William and Lynda Steere Herbarium. Entries in the Virtual Herbarium are created by transcribing the data from the specimen label into an electronic database, and often capturing a digital image of the specimens as well.

We have digitized just over 1 million of our 7.3 million specimens so far. Although we don’t know exactly what objective drives each of the 8,400 daily visits to the Virtual Herbarium, we deduce from reviewing the sources of these “hits” that most users are seeking basic biodiversity information.

Many other herbaria around the world are also digitizing their specimen data, creating an unprecedented tool for biodiversity research. Now that so much specimen data are available in electronic form through the Virtual Herbarium and other similar repositories, we can create very large sets than can help us address questions that were almost impossible before to address. Two important questions that scientists can ask of these large data sets are:

Do plants flower and fruit now at the same time that they used to? The science of phenology studies the timing of plant flowering and fruiting, critical information for agriculture. Herbarium specimens give definitive evidence of when plants were flowering in given locations, and changes in flowering and fruiting times can be correlated with weather patterns to develop predictive models of the effect of climate change on plants in the future. A graduate student from the University of Montpelier, France, visited the Steere Herbarium this year to study specimens of Cecropia, a dominant and ecologically critical group of tropical trees, to determine the spatial variation of flowering and fruiting patterns, and to correlate these changes with climatic factors.

How might future climate change affect plants? Comparing information about what plants grow where now and where they used to grow can provide the basis for a profile of the conditions favored by different species. Scientists then can extrapolate about how those plants might fare in response to future changes in climate. Home and municipal horticulture are huge businesses—home gardening is one of the top American hobbies. The development of new strains of garden plants and trees that can survive a hotter, warmer climate will be a major focus of new plant development, and data from herbarium specimens will inform that process. During the past year, a researcher at Western Washington University borrowed specimens of the stonecrop, Sedum, as part of his study to investigate the evolutionary history of artic/alpine plants in order to estimate the impact that historical climate change has had on the geographic distribution and genetic variation of western plants.

Climate change threatens the survival of ecological communities, individual species, and human heath and well-being. Agriculture, and thus human survival, could well depend on understanding which species are likely to be lost, and what the impact of that loss will be.

A very common question asked by visitors to the Herbarium is, “How many extinct species do you have in the Herbarium?” My standard answer is, “We don’t really know…yet.” We may know that a plant no longer grows where it once grew, but for the vast majority of species, we don’t know enough about its distribution and growth requirements to be sure that it doesn’t exist in a location where no botanist has yet looked for it.

Herbaria do hold the key to understanding which plant species are at the greatest threat for extinction. During the past year, the collections of the Steere Herbarium were consulted by 20 different researchers who were trying to document rare species. For example, a species of bladderwort, Utricularia resupinata, was thought to be extinct in Indiana, however, it was re-collected there recently. Botanists are now consulting herbaria, including the Steere Herbarium, to try to find all the places where this plant may have been collected previously in the state or adjacent areas so that they can develop a profile of the type of habitat where this plant might grow, and visit all existing specimens of the species from Indiana to develop a conservation strategy to protect remaining populations.

While some conservation biologists focus on protecting individual species, others focus on protecting critical areas, usually those that are particularly rich in biodiversity. Efficient conservation planning for a region begins with compiling all available data on biodiversity, then collecting new data to fill taxonomic and geographic gaps in knowledge, and finally correlating the locations of threatened or other priority species to circumscribe areas to be protected.

Resources such as the Steere Herbarium are essential to the compilation and review stages of conservation planning. The data gathered here can help resource managers identify not only areas of high diversity and endemism that should be protected, but also areas that are suitable for development, or contain exploitable resources. For example, last year, a plant ecologist with the Belize Foundation for Research & Environmental Education, requested data from the Herbarium for a project to investigate the vegetation of the Maya Mountains. This project is an important component of the effort to prioritize the protection and conservation zones for Belize. During the past several years, a graduate student from Guyana has been developing a database of the plants of that country based largely on Steere Herbarium specimens to form what she hopes will be the basis for the development of a series of protected regions of that country.

I suppose the question about our holdings of extinct species is a very natural one—the Steere Herbarium is a type of museum, and a museum is a place to see old things that don’t exist anywhere, such as dinosaur bones. I hope that because of the extensive use that scientists make of this collection to preserve biodiversity, that our exhibit of extinct species, should we ever have one, will not be very large!

Donate