Reconstructing community assemblages of a fire-dependent ecosystem
Lydia Harvey & Amélie Przedwiecki
Center for Earth & Environmental Sciences, SUNY Plattsburgh
Background
The Altona Flat Rock has had several documented wildfires, the most recent of which was in 2018. This wildfire lasted for six days and burned approx. 225 ha of the jack pine barrens (Bushey et al. 2023, Thompson et al. 2022). Prior to 2018, there were also fires in 1919, 1940, 1957, and 1965 (Franzi and Adams 1999). There is very little information on these other wildfires, we know when they occurred but we do not know much past that. Based on the jack pine dominated forest at the Flat Rock, it is assumed that there were wildfires prior to the one in 1919, but there are no existing records of them. Knowing the disturbance history of this site for a longer span of time will help to determine disturbance patterns and understand what level and recurrence of wildfire is necessary to maintain jack pine as the dominant tree species. Disturbance events such as these have the potential to cause changes in plant communities and alter the ecosystem as a whole.
​
The goal of this study is to to document long-term changes in forest community composition and fire return interval for the Flat Rock using charcoal, macrofissils, pollen assemblages, and organic carbon content. Charcoal analysis will help us create a timeline of wildfire occurrences at the Flat Rock. Changes in organic carbon as loss-on-ignition will indicate changes in covertype, such as the formation of the wetland. Additionally, macrofossils and pollen assemblages will provide insight on changes in the plant community over time and in response to the wildfires (i.e., the arrival time of jack pine).
Methods
A 3.24 meter core was collected from a poor fen wetland at the Flat Rock in January 2024 using a Russian peat borer. The core was sectioned into one centimeter samples and broken into three subsamples. For two of the subsamples, approximately one cubic centimeter of sediment was taken for both loss-on-ignition and pollen analysis. The rest of the sample was saved for macrofossil and charcoal analysis. To determine the age of the core and to document when wildfires and changes in the plant community occurred, two sediment samples, one from the bottom of the core at 324 cm and one at 160 cm were send out for radiocarbon dating. We have recently recieved funding to send out two additional samples for dating to increase the accuracy of our age-depth model.
LOI & Pollen and Analysis
Macrofossils and Charcoal
Bibliograpgy
Bushey, D., Osmer, M., Green, H., Garneau, D., & Lesser, M. (2023). Forest resilience and regeneration dynamics following wildfire disturbance. Ecosphere, 14(9), e4655.
​
Cave, H.; Adams, M.; Jaeger, T.; Peet, T.; Staats, L.; Garneau, D.; Lesser, M. Wildlife Response to Wildfire in a Northern New York Jack Pine Barrens. Forests 2021, 12, 676. https://doi.org/ 10.3390/f12060676
​
Franzi, D. A., & Adams, K. B. (1999, October). The origin and fate of the sandstone pavement pinebarrens in northeastern New York. In New England Intercollegiate Geologic Conference Guidebook (No. 91, pp. 201-212).
​
Rull, V. (2010). Ecology and palaeoecology: two approaches, one objective. The Open Ecology Journal, 3(1).
​
Thompson, H.M.; Lesser, M.R.; Myers, L.; Mihuc, T.B. Insect Community Response Following Wildfire in an Eastern North American Pine Barrens. Forests 2022, 13, 66. https://doi.org/10.3390/ f13010066
