North American Orchid Conservation Center

Melissa K. McCormick, Dennis F. Whigham, Rachel Rock-Blake, Hope E.A. Brooks

North American Orchid Conservation Center (NAOCC) and Smithsonian Environmental Research Center (SERC)

Orchids are widely threatened and endangered worldwide, but efforts to conserve and restore them has been limited by not knowing about the pollinators and fungi they need to grow and reproduce. The absence of appropriate mycorrhizal fungi can limit where orchids grow, but little is known about how the abundance and diversity of appropriate mycorrhizal fungi can affect orchid growth and population dynamics. Light availability is also expected to affect population dynamics, but with orchid life stages occurring predominantly above- or below-ground it seems reasonable to hypothesize that different life stages would be driven by above- or below-ground factors. In particular, emergent, green, above-ground stages would be most impacted by light, while seed, protocorm, and dormant stages would be most affected by mycorrhizal fungi. We hypothesized that the distribution, abundance, and emergence of the globally rare temperate, terrestrial orchid, Isotria medeoloides, would be driven at least partly by their mycorrhizal fungi. We combined the use of specific PCR primers, quantitative real-time PCR, and spatially nested soil samples to measure the distribution and abundance of mycorrhizal fungi that associate with I. medeoloides and measurement of light availability and orchid growth in three distinct studies. We found that I. medeoloides distribution and emergence were affected by the distribution and abundance of their mycorrhizal fungi in the soil. In contrast, plant growth during the growing season and the likelihood of flowering the subsequent year were more affected by light availability. We conclude that orchid conservation and studies of the drivers of orchid population dynamics need to consider both the mycorrhizal fungi and light resources they require.

Contributing Author(s): 
Date Recorded: 
Wednesday, March 4, 2020

Dennis Whigham and Julianne McGuinness, North American Orchid Conservation Center

The North American Orchid Conservation Center (NAOCC) was developed by the Smithsonian and the U.S. Botanic Garden to conserve the diversity of native orchids in the U.S. and Canada. NAOCC ecologically-based conservation model has three guiding principles: Preservation through seed and fungal banks, Propagation, Education. NAOCC has a growing network of public and private collaborators working to collect and store seeds of native orchids to further the understanding their ecology, preserve genetic diversity, and provide material for use in research that supports propagation and restoration efforts. NAOCC's collaborative model for orchid conservation is guiding a new project to develop best practices and storage protocols for orchid seeds and their fungal associates. To address the urgent need for evidence-based standardized procedures, NAOCC and a number of its collaborators will study storage practices, conduct germination tests, and develop protocols for each species. Chicago Botanic Garden (CBG) took the lead on a grant application to the IMLS for funding for this project. NAOCC joins CBG, the New England Wild Flower Society, Minnesota Landscape Arboretum, Atlanta Botanical Garden, Fairchild Tropical Botanic Garden, Illinois College, the Mid-Atlantic Regional Seed Bank, and the Naples Botanical Garden to conduct the first systematic analysis of its kind regarding seed storage practices for North American native orchid species.

Contributing Author(s): 
Date Recorded: 
Friday, May 4, 2018