Oral Presentation

63.75 inches of rainfall and snowmelt water made 2018 the wettest year in 122 years of record for the Spring Creek Watershed in Centre County, PA. Yet it experienced very limited overbank stream flooding even though its 30-year average annual precipitation of 40.66 inches was exceeded by 57%. This presentation will explain how the unique combination of its hydrogeologic characteristics enabled this karst watershed to convert the excess rainfall into stored groundwater recharge instead of floodwater runoff. Much of the storm-water runoff from the watershed’s surrounding mountain ridges flowed into sinkholes at the base of the ridges and was directly converted into groundwater recharge, thereby mitigating storm-water flooding. You will learn the details of how this watershed’s unique carbonate flow systems took in and stored 38 billion gallons of groundwater recharge from the 70 billion gallons of above-normal precipitation for a capture ratio of 55%.

The perennial wildflower, Baptisia australis var. australis (L.) R. Br. is found along only four waterways in Pennsylvania: the Allegheny River, Youghiogheny River, Clarion River, and Red Bank Creek. Because of its limited distribution and small number of extant populations, B. australis var. australis is considered state-threatened in Pennsylvania. In addition, the riparian prairie habitat that Pennsylvania Baptisia australis var. australis is restricted to is also in decline and considered vulnerable in the state. Because of conservation concerns for Baptisia australis var. australis in Pennsylvania, gaining insights into the natural history and genetics of the taxon is useful for conservation practitioners. This project seeks to determine the genetic structure and health of known native populations and apply that information to understanding riparian gene flow, as well as establishing conservation units. Genotyping-by-sequencing (GBS) was used to collect genomic data for use in population genetics analyses. My work synthesizes these data to gain insight into the metapopulation dynamics of this riparian system and examine patterns of gene flow. We found that there are three genetic groups of Baptisia australis var. australis in Pennsylvania, with one of these showing internal genetic structure. This finding can be applied to management units for the taxon. Some Pennsylvania populations are becoming increasingly isolated as well as dwindling in population size, making now an ideal time to collect seeds and facilitate gene flow while levels of inbreeding are relatively low. My research will inform the conservation status of Baptisia australis var. australis in Pennsylvania, as well as clarify lingering uncertainties about gene flow in riparian plant populations.