Authors: Julie Commerford*, Saginaw Valley State University, Sydney Gainforth, Saginaw Valley State University, Gabrielle Gittens, Western Michigan University, Jeremy Wilson, Indiana University-Purdue University Indianapolis, Broxton W. Bird, Indiana University-Purdue University Indianapolis
Topics: Paleoenvironmental Change, Biogeography
Keywords: paleoenvironmental change, temperate forest, pollen, resilience, human disturbance
Session Type: Virtual Paper
Start / End Time: 9:35 AM / 10:50 AM
Room: Virtual 40
Presentation File: No File Uploaded
Resilience is often assessed by ecosystem’s ability to recover from disturbances. However, re-establishment of an ecosystem sometimes takes longer than can be measured over a human lifetime. In addition, post-disturbance ecosystems can be different in composition than pre-disturbance, which makes it impossible to assess resilience over the span of a few years because it is not immediately obvious whether and how an ecosystem has recovered. For these reasons, a long-term perspective over several decades to centuries is necessary to fully evaluate ecosystem resilience. Here, we examined 110 pollen samples from a 3000-year sediment record from Avery Lake, Illinois, to reconstruct vegetation composition in a temperate forest following land clearing by early groups of Native Americans between 300 BCE-300 CE and 1150-1450 CE. A shift in moisture regime occurred at the end of the latter occupation, which provides an opportunity to examine vegetation response to two consecutive disturbances. In addition to examining pollen assemblage composition, we calculated two diversity metrics to infer vegetation dynamics. Arboreal pollen increased following human abandonment of the site, but the assemblage was dominated by different arboreal taxa than prior to human occupation, likely caused by concurrent shifts in moisture regime.