Title

Shallow lake trophic status linked to late Holocene climate and human impacts.

SelectedWorks Author Profiles:

Joseph M. Smoak

Document Type

Article

Publication Date

2009

Date Issued

January 2009

Date Available

January 2012

Abstract

Lake Mattamuskeet, North Carolina, USA is a large (162 km2) and shallow (mean depth = 1 m) coastal lake, which was significantly modified to support agricultural activities following European settlement in 1850. Paleolimnological proxies measured on a 400-cm sediment core collected from Lake Mattamuskeet reveal shifts in organic matter input and primary producer community structure in response to climatic and human impacts on the lake during the late Holocene. Stratigraphic changes in organic matter content, nutrients, metals, lignin phenols and photosynthetic pigments were used to divide the sediment core into three intervals. Interval I includes sediment deposited between A.D. 360-1584 and indicates a clear-water, sand-bottom state with low algal abundance. In addition, the lake catchment area experienced two significant fires during this interval that were recorded as charcoal layers in the core around A.D. 360 and A.D. 1435 (calibrated 14C AMS dates). Trophic structure changed with the onset of Interval II (A.D. 1584-1860) when total algal abundance increased, and the primary producer community was comprised primarily of diatoms, chrysophytes, cryptophytes and cyanobacteria. During this interval there was also an increase in terrestrial organic material input into the lake as well as a shift in plant type from woody gymnosperms to non-woody angiosperms as determined from lignin data. Sediment deposited in Lake Mattamuskeet following European settlement (Interval III, A.D. 1860-present) suggests a dramatic increase in organic matter deposition, metals, primary-producer abundance and the onset of cyanobacterial dominance. Sedimentary evidence indicates that shallow-water primary producers can respond rapidly to climate change and human development.

Comments

Abstract only. Full-text article is available only through licensed access provided by the publisher. Published in Journal of Paleolimnology, 42, 51-64. doi 10.1007/s10933-008-9247-x Members of the USF System may access the full-text of the article through the authenticated link provided.

Language

en_US

Publisher

Kluwer Academic Publishers

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.