Patterns and drivers of Holocene vegetational change near the prairie–forest ecotone in Minnesota: revisiting McAndrews’ transect
Article first published online: 28 JUN 2008
© The Authors (2008). Journal compilation © New Phytologist (2008)
Volume 179, Issue 2, pages 449–459, July 2008
How to Cite
Nelson, D. M. and Hu, F. S. (2008), Patterns and drivers of Holocene vegetational change near the prairie–forest ecotone in Minnesota: revisiting McAndrews’ transect. New Phytologist, 179: 449–459. doi: 10.1111/j.1469-8137.2008.02482.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- Received: 18 February 2008; Accepted: 20 March 2008
- McAndrews’ transect;
- prairie–forest border
- • Holocene vegetational dynamics along the prairie–forest border of Minnesota were first documented in McAndrews’ classic work. Despite numerous subsequent paleo-studies, a number of questions remain unanswered about the vegetation history of the region. Here, pollen, stable-isotope, mineral, and charcoal data are described from three lakes near McAndrews’ sites. These data were compared with other paleoenvironmental records to reconstruct vegetation, aridity, and fire.
- • The climate was relatively wet with increasing summer temperatures before ~8000 yr before present (BP). The rates of changes were asymmetric for the onset and termination of middle-Holocene aridity, with an abrupt increase at ~8000 yr BP and a gradual, but variable, decline from ~7800 to 4000 yr BP.
- • Early-Holocene coniferous forests changed to mixed-grass prairie without an intervening period of tallgrass prairie or deciduous forest, whereas the retreat of prairie was characterized by transitions from mixed-grass to tallgrass prairie to deciduous forest and finally to coniferous forest. Within the middle Holocene, the composition and structures of grass-dominated vegetation varied both temporally and spatially.
- • Fire primarily responded to changes in climate and fuel loads. Vegetation was more strongly influenced by climatic changes than by fire-regime shifts.