Integration of lakes and streams in a landscape perspective: the importance of material processing on spatial patterns and temporal coherence

• Published in: Freshwater Biology
• Main Authors: Kling, George W., Kipphut, George W., Miller, Michael M., O'Brien, W. JohN.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2000
• Subjects: Arctic; Alaska
• Online Access: http://dx.doi.org/10.1046/j.1365-2427.2000.00515.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2427.2000.00515.x; https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2427.2000.00515.x

1. We studied the spatial and temporal patterns of change in a suite of twenty‐one chemical and biological variables in a lake district in arctic Alaska, U.S.A. The study included fourteen stream sites and ten lake sites, nine of which were in a direct series of surface drainage. All twenty‐four sites were sampled between one and five times a year from 1991 to 1997. 2. Stream sites tended to have higher values of major anions and cations than the lake sites, while the lake sites had higher values of particulate carbon, nitrogen, phosphorous and chlorophyll a . There were consistent and statistically significant differences in concentrations of variables measured at the inlet versus the outlet of lakes, and in variables measured at upstream versus downstream sites in the stream reaches which connect the lakes. In‐lake processing tended to consume alkalinity, conductivity, H + , DIC, Ca 2+ , Mg 2+ , CO 2 , CH 4 , and NO 3 – , and produce K + and dissolved organic carbon (DOC). In‐stream processing resulted in the opposite trends (e.g. consumption of K + and DOC), and the magnitudes of change were often similar to those measured in the lakes but with the opposite sign. 3. Observed spatial patterns in the study lakes included mean concentrations of variables which increased, decreased or were constant along the lake chain from high to low altitude in the catchment (stream sites showed no spatial patterns with any variables). The strongest spatial patterns were of increasing conductivity, Ca 2+ , Mg 2+ , alkalinity, dissolved inorganic carbon and pH with lake chain number (high to low altitude in the basin). These patterns were partly determined by the effect of increasing catchment area feeding into lakes further downslope, and partly by the systematic processing of materials in lakes and in the stream segments between lakes. 4. Synchrony (the temporal coherence or correlation of response) of variables across all lakes ranged from 0.18 for particulate phosphorus to 0.90 for Mg 2+ the average synchrony for all ...