Quantitative and qualitative relationships between planktonic diatom communities and diatom assemblages in sedimenting material and surface sediments in Lake Baikal, Siberia

摘要: Endemic planktonic diatoms are a major component of Lake Baikal sediments during interglacial periods. To investigate how these diatom assemblages altered sediment formation, quantitative plankton monitoring (1995‐1998) was integrated with trapping over 2 yr (1996‐1997) in Baikal’s southern basin (depth ;1,400 m). The traps consisted both open (;6 monthly) and sequential (;2 weekly) collectors deployed throughout the water column. Sedimentation seasonal, species composition, valve abundance, total dry mass reflecting changes communities. Sedimented were transmitted largely intact to deepest (;1,300‐1,390 m); some compositional blurring occurred from differential sinking rates dissolution valves. A rapid flux event Aulacoseira skvortzowii A. baicalensis recorded summer 1997 particle between 60 100 m d 21 fluxes . 5gm 22 Although evident for all species, more delicate taxa preferentially affected (e.g., vegetative cells fineSynedra species), whereas Nitzschia acicularis valves almost entirely dissolved within Comparing trap those nearby core tops demonstrated that fundamental taphonomic change occurs surface sediment, sedimentary accumulation being only about 1% deposition production rates. Dissolution significant explaining 5‐30% variance levels (plankton, samples, sediments). Results indicate diatom-based paleoclimatic records could be improved refined by taking considerations into account.