TY - JOUR
T1 - Patterns and drivers of Holocene vegetational change near the prairie-forest ecotone in Minnesota
T2 - Revisiting McAndrews' transect
AU - Nelson, David M.
AU - Hu, Feng Sheng
PY - 2008/7
Y1 - 2008/7
N2 - • 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.
AB - • 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.
KW - Climate
KW - Fire
KW - Holocene
KW - McAndrews' transect
KW - Minnesota
KW - Pollen
KW - Prairie-forest border
UR - http://www.scopus.com/inward/record.url?scp=47249136489&partnerID=8YFLogxK
U2 - 10.1111/j.1469-8137.2008.02482.x
DO - 10.1111/j.1469-8137.2008.02482.x
M3 - Article
C2 - 19086180
AN - SCOPUS:47249136489
SN - 0028-646X
VL - 179
SP - 449
EP - 459
JO - New Phytologist
JF - New Phytologist
IS - 2
ER -