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Smithsonian Environmental Research Center

Understanding Ecosystems for a Sustainable Future

Plant Ecology

Principal Investigator

Dennis Whigham

whighamd@si.edu

443-482-2226

Curriculum Vitae

Plant Ecology Projects

Headwater streams in Alaska are rich in biodiversity, including juvenile salmon that eventually return to the ocean.

Alaska headwater streams - linking land, wetlands, streams
This project explores how fungi contribute to speciation and diversification in the orchid genus Platanthera and investigates how preferences for fungal use are inherited by studying parent species and their hybrid offspring.

Fungal interactions and speciation in orchids
The project goal is to assess the degree to which leaf endophytes (fungi and bacteria that live in leaf tissues) mediate the effects of tree diversity on leaf chemistry (metabolome), herbivore communities, and tree productivity.

Impacts of tree diversity on leaf endophytes
We are following the genetic trail left by invading Phragmites australis to understand what factors have promoted invasion by this non-native wetland plant.

Invasion Forensics and Invasive Phragmites
Non-native Phragmites australis is now a dominant species in much of the Chesapeake Bay. We are determining how land use has affected its spread.

Land Use and Phragmites Invasion
Non-native earthworms dominate the soil of many mid-Atlantic forests. We are investigating how they affect they mycorrhizal associations that plants depend on.

Mycorrhizal Ecology and Invasive Earthworms
We are investigating how the identity of the mycorrhizal fungi associated with the orchid Corallorhiza odontorhiza affect its ability to tolerate climate variation.

Mycorrhizal Fungi Affect Orchid Dynamics
In North America, more than 60% of the over 230 known species are threatened or endangered in some part of their range of distribution and a number of species have been extirpated in some states.

North American Orchid Conservation Center
Knowledge of orchid pollinator relationships is incomplete, with no documented pollinators for almost 50% of orchids,

Orchid Pollinator Diversity
The goal of the Palau Orchid Conservation Initiative is to determine how ecological and environmental variables influence orchid diversity and distributions so that effective conservation strategies can be developed.

Palau Orchid Conservation
We are working to determine the effect of prescribed burns on Helonias bullata (swamp pink).

Prescribed Burns and Conserving the Threatened Swamp Pink
Protecting orchids means also protecting the mycorrhizal fungi they need to grow. We are working to understand the role mycorrhizal fungi play in orchid conservation.

Using Mycorrhizal Ecology to Conserve Rare Orchids

Plant Ecology Projects

Alaska headwater streams - linking land, wetlands, streams

Fungal interactions and speciation in orchids

Impacts of tree diversity on leaf endophytes

Invasion Forensics and Invasive Phragmites

Land Use and Phragmites Invasion

Mycorrhizal Ecology and Invasive Earthworms

Mycorrhizal Fungi Affect Orchid Dynamics

North American Orchid Conservation Center

Orchid Pollinator Diversity

Palau Orchid Conservation

Prescribed Burns and Conserving the Threatened Swamp Pink

Using Mycorrhizal Ecology to Conserve Rare Orchids