Temporal and spatial heterogeneity in lacustrine δ13CDIC and δ18ODO signatures in a large mid-latitude temperate lake

Bass, A. M., Waldron, S. , Preston, T. and Adams, C. E. (2010) Temporal and spatial heterogeneity in lacustrine δ13CDIC and δ18ODO signatures in a large mid-latitude temperate lake. Journal of Limnology, 69(2), pp. 341-349.

Bass, A. M., Waldron, S. , Preston, T. and Adams, C. E. (2010) Temporal and spatial heterogeneity in lacustrine δ13CDIC and δ18ODO signatures in a large mid-latitude temperate lake. Journal of Limnology, 69(2), pp. 341-349.

Full text not currently available from Enlighten.

Abstract

Modelling limnetic carbon processes is necessary for accurate global carbon models and stable isotope analysis can provide additional insight of carbon flow pathways. This research examined the spatial and temporal complexity of carbon cycling in a large temperate lake. Dissolved inorganic carbon (DIC) is utilised by photosynthetic organisms and dissolved oxygen (DO) is used by heterotrophic organisms during respiration. Thus the spatial heterogeneity in the pelagic metabolic balance in Loch Lomond, Scotland was investigated using a combined natural abundance isotope technique. The isotopic signatures of dissolved inorganic carbon (δ13CDIC) and dissolved oxygen (δ18ODO) were measured concurrently on four different dates between November 2004 and September 2005. We measured isotopic variation over small and large spatial scales, both horizontal distance and depth. δ13CDIC and δ18ODO changed over a seasonal cycle, becoming concurrently more positive (negative) in the summer (winter) months, responding to increased photosynthetic and respiratory rates, respectively. With increasing depth, δ13CDIC became more negative and δ18ODO more positive, reflecting the shift to a respiration-dominated system. The horizontal distribution of δ13CDIC and δ18ODO in the epilimnion was heterogeneous. In general, the south basin had the most positive δ13CDIC, becoming more negative with increasing latitude, except in winter when the opposite pattern was observed. Areas of local variation were often observed near inflows. Clearly δ13CDIC and δ18ODO can show large spatial heterogeneity, as a result of varying metabolic balance coupled with inflow proximity and thus single point sampling to extrapolate whole lake metabolic patterns can result in error when modelling large lake systems Whilst we advise caution when using single point representation, we also show that this combined isotopic approach has potential to assist in constructing detailed lake carbon models.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Waldron, Professor Susan and Preston, Professor Thomas and Bass, Dr Adrian and Adams, Professor Colin
Authors: Bass, A. M., Waldron, S., Preston, T., and Adams, C. E.
Subjects:Q Science > QE Geology
College/School:College of Medical Veterinary and Life Sciences > Institute of Biodiversity Animal Health and Comparative Medicine
College of Science and Engineering > School of Geographical and Earth Sciences
College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Journal of Limnology
Publisher:PAGEpress
ISSN:1723-8633
Published Online:01 August 2010

University Staff: Request a correction | Enlighten Editors: Update this record