Advances in our knowledge of the flora of northeastern North America during the past two decades. The New York Botanical Garden is sponsoring a complete revision of Manual of Vascular Plants of Northeastern United States and Adjacent Canada by Henry Gleason and Arthur Cronquist (1991). Gleason and Cronquist is the most recent in a long line of books on the spontaneous flora of northeastern North America. The rapid pace and broad scope of botanical advances in the past two decades amply justify a revision. This presentation will review these advances, as well as the kinds of changes necessary, the plan for the revision, and the innovations relative to Gleason and Cronquist. As with Gleason and Cronquist, the New Manual will be first and foremost a tool to facilitate accurate identifications of the flora (ca. 5000 species) in a vast region (all or portions of 22 U.S. states, including Pennsylvania, and 5 Canadian provinces). In addition, the New Manual will provide detailed information on geographic distributions, habitat, conservation status, and etymologies.
Species Interactions in a Pennsylvania Forest: Native Plants, Invasive Plants and Herbivores. Exotic species invasive success is context-dependent. Species interactions within native communities are hypothesized to favor or thwart invasion success. I present results of long-term studies on species interaction in Pennsylvanian forests where the herbivore Odocoileus virginianus (white-tailed deer) is (over)abundant and the allelopathic species Alliaria petiolata (garlic mustard) is aggressively invading. Results from field experiments tracking native and invasive plant population dynamics in paired plots (deer exclusion [fenced] vs. presence [unfenced]) agree with results from investigations across a deer browsed gradient. Deer suppress all focal native species in our study. Further, A. petiolata maintained explosive annual population growth rate, λ=1.33, and high densities in unfenced plots while in plots without deer native populations rebounded, A. petiolata’s growth rate plummeted to λ=0.88, and its density became low. These results link high deer abundance to altered native-invasive species interactions and invader success. Controlling ungulate numbers may diminish invaders’ success worldwide with profound implications for economic and ecosystem functions of landscapes they currently dominate.
Stewardship of Wetlands within Northwestern Pennsylvania. Several alder–sedge fens, greater bur-reed marshes and tussock sedge marshes within northwestern Pennsylvania have suffered severe degradation during the last few decades due to encroachment of non-native narrow-leaf cattail (Typha angustifolia), reed grass (Phragmites australis ssp. australis), canary grass (Phalaris arundinacea) and purple loosestrife (Lythrum salicaria) during the last 20 years. An effort to restore emergent marshes and palustrine sand plains at Presque Isle was initiated 20 years ago. Ten years ago, Cleveland Museum of Natural History staff initiated the restoration of two alder–sedge fens, one in Erie County and one in Crawford County. A program to remove the four main invaders at first appearance within two other fens, one in eastern Crawford County and one in Warren County was also established ten years ago. Removal at first appearance has proved to be a more effective method of stewardship due to the establishment of a non-native seed bank if removal is initiated several years after the first invasions.
Alfred E. Schuyler
Colonial and Early American Botany. Southeastern Pennsylvania was the hub of American botany from the 1730s to the 1830s. The stimulus came from the desire by English aristocrats to obtain American plants and the desire by Europeans and Americans to name, describe, and illustrate the American flora. Furthermore Philadelphia institutions provided resources for botanical activities, along with gardens and herbaria. The botanists who fulfilled these desires and utilized Philadelphia resources included John Bartram, William Bartram, James Logan, Peter Kalm, William Young, Humphry Marshall, André Michaux, Henry Muhlenberg, Benjamin Smith Barton, Frederick Pursh, John Lyon, François Michaux, William W. P. C. Barton, Lewis David von Schweinitz, Constantine Samuel Rafinesque, and Thomas Nuttall. This presentation discusses how this impressive array laid the foundation for American botany.
Current Issues in Botany — Botanical Capacity Shortcomings. The botanical community plays a mission-critical role in researching, conserving, and sustainably managing the nation’s plant diversity and resources. Botanical expertise is required to address current and future issues, including climate change mitigation, habitat restoration, invasive species control, and rare species conservation. Yet despite the fundamental role botanical capacity plays in tackling these issues, a recent assessment revealed severe shortages of botanists at government agencies, a wave of upcoming retirements, and an alarming decline in botanical degree programs and course offerings at the nation’s colleges and universities. The result of a year-long project which surveyed nearly 1,600 members of the United States botanical community, the botanical capacity assessment project detailed the importance of building links between stakeholders throughout the botanical community. It makes the case for action across all sectors to work more strategically to effectively pool resources and ensure program sustainability and conservation success into the future.