Development of the mixed conifer forest in northern New Mexico and its relationship to Holocene environmental change

Quaternary Research - Tập 69 - Trang 263-275 - 2008
R. Scott Anderson1,2, Renata B. Jass2, Jaime L. Toney2, Craig D. Allen3, Luz M. Cisneros-Dozal4, Marcey Hess4, Jeff Heikoop4, Julianna Fessenden4
1Center for Environmental Sciences & Education, Box 5694, Northern Arizona University, Flagstaff, AZ 86011, USA
2Quaternary Sciences Program & Bilby Research Center, Box 6013, Northern Arizona University, Flagstaff, AZ 86011, USA
3U.S. Geological Survey, Jemez Mountains Field Station, Bandelier National Monument, HCR-1, Box 1, #15, Los Alamos, NM 87544, USA
4Earth & Environmental Sciences Division, Hydrology, Geochemistry & Geology Group, EES-6, MS-D462, Los Alamos National Laboratory, Los Alamos, NM 87545, USA

Tóm tắt

Chihuahueños Bog (2925 m) in the Jemez Mountains of northern New Mexico contains one of the few records of late-glacial and postglacial development of the mixed conifer forest in southwestern North America. The Chihuahueños Bog record extends to over 15,000 cal yr BP. AnArtemisiasteppe, then an openPiceawoodland grew around a small pond until ca. 11,700 cal yr BP whenPinus ponderosabecame established. C/N ratios,δ13C andδ15N values indicate both terrestrial and aquatic organic matter was incorporated into the sediment. Higher percentages of aquatic algae and elevated C/N ratios indicate higher lake levels at the opening of the Holocene, but a wetland developed subsequently as climate warmed. From ca. 8500 to 6400 cal yr BP the pond desiccated in what must have been the driest period of the Holocene there. C/N ratios declined to their lowest Holocene levels, indicating intense decomposition in the sediment. Wetter conditions returned after 6400 cal yr BP, with conversion of the site to a sedge bog as groundwater levels rose. Higher charcoal influx rates after 6400 cal yr BP probably result from greater biomass production rates. Only minor shifts in the overstory species occurred during the Holocene, suggesting that mixed conifer forest dominated throughout the record.

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Quaternary Research

Tập 69

263-275

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