Holocene palaeoenvironmental records from two subalpine lakes in southern British Columbia, based on chironomid and pollen analyses

Holocene climate in British Columbia has been mainly reconstructed from palynological research. In this study fossil Chironomidae were analyzed from sediments of two subalpine lakes, in order to reconstruct palaeoenvironmental changes. Midge stratigraphies and a midge-temperature inference model (based on a 51 lake training set for southern British Columbia) were used to infer mean July air temperatures and reconstruct Holocene climatic regimes at each lake.;Chaoborus and Microtendipes are abundant during the early Holocene at Frozen Lake, suggesting warmer temperatures than present. Cold-stenotherms subsequently increase as temperate midge taxa decline, indicating a cooling trend to the present.;Warm-water indicators, are present in the early Holocene at Eagle Lake, but disappeared during the mid-Holocene when temperatures likely cooled. A resurgence of warm indicators in the late Holocene contradicts the evidence of continued cooling typically seen in other reconstructions. (Abstract shortened by UMI.).