A 15,000 year record of vegetation and climate change from a treeline lake in the Rocky Mountains, Wyoming, USA

作者：Mensing Scott^*; Korfmacher John; Minckley Thomas; Musselman Robert

来源：The Holocene, 2012, 22(7): 739-748.

DOI：10.1177/0959683611430339

• climate change
• conifer stomata
• Holocene
• pollen
• Rocky Mountains
• treeline
• United States
• Wyoming

Future climate projections predict warming at high elevations that will impact treeline species, but complex topographic relief in mountains complicates ecologic response, and we have a limited number of long-term studies examining vegetation change related to climate. In this study, pollen and conifer stomata were analyzed from a 2.3 m sediment core extending to 15,330 cal. yr BP recovered from a treeline lake in the Rocky Mountains of Wyoming. Both pollen and stomata record a sequence of vegetation and climate change similar in most respects to other regional studies, with sagebrush steppe and lowered treeline during the Late Pleistocene, rapid upward movement of treeline beginning about 11,500 cal. yr BP, treeline above modern between similar to 9000 and 6000 cal. yr BP, and then moving downslope similar to 5000 cal. yr BP, reaching modern limits by similar to 3000 cal. yr BP. Between 6000 and 5000 cal. yr BP sediments become increasingly organic and sedimentation rates increase. We interpret this as evidence for lower lake levels during an extended dry period with warmer summer temperatures and treeline advance. The complex topography of the Rocky Mountains makes it challenging to identify regional patterns associated with short term climatic variability, but our results contribute to gaining a better understanding of past ecologic responses at high elevation sites.

• 出版日期2012-7