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• 1. [Article] Allochthonous material income and decomposition in Findley Lake

  Citation × Citation Citation Abstract Copy Title: Allochthonous material income and decomposition in Findley Lake Author: U.S. International Biological Program. Coniferous Forest Biome, Gara, Robert I., University of Washington, Rau, Gregory Hudson Title: Allochthonous material income and decomposition in Findley Lake Author: U.S. International Biological Program. Coniferous Forest Biome, Gara, Robert I., University of Washington, Rau, Gregory Hudson Close

• 2. [Article] Grazing and production by zooplankton in lakes of contrasting trophic status : a progress report

  Grazing rates and density of the crustacean zooplankton were measured in Findley and Chester Morse Lakes and Lake Sammamish, Washington. Sample analysis is incomplete at reporting time, thus estimates ...

  Citation × Citation Citation Abstract Copy Title: Grazing and production by zooplankton in lakes of contrasting trophic status : a progress report Author: Pederson, G. L., U.S. International Biological Program. Coniferous Forest Biome, Stoll, Richard Kenneth, Welch, E. B. (Eugene B.), University of Washington Grazing rates and density of the crustacean zooplankton were measured in Findley and Chester Morse Lakes and Lake Sammamish, Washington. Sample analysis is incomplete at reporting time, thus estimates of production from examination of life stage biomass changes was not possible. Maximum density of crustacean zooplankton was about 10/1 in the water column of oligotrophic Findley and Chester Morse Lakes and 70/1 in mesotrophic-eutrophic Lake Sammamish during 1972. Densities averaged about 10 times greater in Lake Sammamish than in the other lakes. Copepods comprised most of the numbers in all three lakes. Grazing apparently represents a sizable loss to phytoplankton in the three lakes feeding rates experimentally determined in situ from changes in ¹⁴C tagged phytoplankton ranged from nearly one half to over six times the algal biomass per day. However, feeding rate was always less than phytoplankton productivity. Title: Grazing and production by zooplankton in lakes of contrasting trophic status : a progress report Author: Pederson, G. L., U.S. International Biological Program. Coniferous Forest Biome, Stoll, Richard Kenneth, Welch, E. B. (Eugene B.), University of Washington Grazing rates and density of the crustacean zooplankton were measured in Findley and Chester Morse Lakes and Lake Sammamish, Washington. Sample analysis is incomplete at reporting time, thus estimates of production from examination of life stage biomass changes was not possible. Maximum density of crustacean zooplankton was about 10/1 in the water column of oligotrophic Findley and Chester Morse Lakes and 70/1 in mesotrophic-eutrophic Lake Sammamish during 1972. Densities averaged about 10 times greater in Lake Sammamish than in the other lakes. Copepods comprised most of the numbers in all three lakes. Grazing apparently represents a sizable loss to phytoplankton in the three lakes feeding rates experimentally determined in situ from changes in ¹⁴C tagged phytoplankton ranged from nearly one half to over six times the algal biomass per day. However, feeding rate was always less than phytoplankton productivity. Close

• 3. [Article] Phytoplankton productivity and response to altered nutrient content in lakes of contrasting trophic state

  Lakes Findley, Chester Morse and Sammamish, Washington, are characterized by one major outburst of phytoplankton productivity and biomass (mainly diatoms) with usually no or low fall activity. Vernal outbursts ...

  Citation × Citation Citation Abstract Copy Title: Phytoplankton productivity and response to altered nutrient content in lakes of contrasting trophic state Author: Rock, C. A., U.S. International Biological Program. Coniferous Forest Biome, Hendrey, George R., Welch, E. B. (Eugene B.), University of Washington Lakes Findley, Chester Morse and Sammamish, Washington, are characterized by one major outburst of phytoplankton productivity and biomass (mainly diatoms) with usually no or low fall activity. Vernal outbursts were often delayed in some lakes and years probably by unfavorable climate (snow cover and cloudy rainy conditions). Mean spring-summer productivity ranged from 270 mgC/m² day in the most oligotrophic lake, Findley, to nearly 1000 mgC/m² day in mesotrophic-eutrophic Lake Sammamish. The range in mean Chlorophyll a content was 0.8 to 10 ug/l for the same lakes respectively. Mean biomass within and between the lakes was related to winter phosphorus content but not to nitrogen. However, nitrogen (N) and phosphorus (P) were simultaneously limiting productivity increase in the three lakes in summer. Carbon assimilation in response to added P showed increasing half-saturation constants for the natural phytoplankton progressing from oligotrophy to eutrophy. While diversion of over 1/2 the phosphorus from nearby Lake Washington during 1963-1967 was followed by reduction in winter mean P content and a rapid shift from eutrophy to mesotrophy (Edmondson 1970), mean winter P content and measured characteristics of plankton response have not changed significantly in Lake Sammamish following a diversion of similar magnitude. P availability in the water column (winter mean content) appears to be controlled by precipitation with Fe to a greater extent than in Lake Washington. Title: Phytoplankton productivity and response to altered nutrient content in lakes of contrasting trophic state Author: Rock, C. A., U.S. International Biological Program. Coniferous Forest Biome, Hendrey, George R., Welch, E. B. (Eugene B.), University of Washington Lakes Findley, Chester Morse and Sammamish, Washington, are characterized by one major outburst of phytoplankton productivity and biomass (mainly diatoms) with usually no or low fall activity. Vernal outbursts were often delayed in some lakes and years probably by unfavorable climate (snow cover and cloudy rainy conditions). Mean spring-summer productivity ranged from 270 mgC/m² day in the most oligotrophic lake, Findley, to nearly 1000 mgC/m² day in mesotrophic-eutrophic Lake Sammamish. The range in mean Chlorophyll a content was 0.8 to 10 ug/l for the same lakes respectively. Mean biomass within and between the lakes was related to winter phosphorus content but not to nitrogen. However, nitrogen (N) and phosphorus (P) were simultaneously limiting productivity increase in the three lakes in summer. Carbon assimilation in response to added P showed increasing half-saturation constants for the natural phytoplankton progressing from oligotrophy to eutrophy. While diversion of over 1/2 the phosphorus from nearby Lake Washington during 1963-1967 was followed by reduction in winter mean P content and a rapid shift from eutrophy to mesotrophy (Edmondson 1970), mean winter P content and measured characteristics of plankton response have not changed significantly in Lake Sammamish following a diversion of similar magnitude. P availability in the water column (winter mean content) appears to be controlled by precipitation with Fe to a greater extent than in Lake Washington. Close

• 4. [Article] Benthic macroinvertebrate production

  Macroinvertebrates were sampled on a regular basis from March to October 1973. A relationship between chironomid length and biomass was established. Production equations to be used for these insects are ...

  Citation × Citation Citation Abstract Copy Title: Benthic macroinvertebrate production Author: Bissonnette, Pam, Taub, F. B. (Frieda B.), University of Washington, U.S. International Biological Program. Coniferous Forest Biome Macroinvertebrates were sampled on a regular basis from March to October 1973. A relationship between chironomid length and biomass was established. Production equations to be used for these insects are reported. A similar length/weight relationship is presently being explored for the oligochaetes. A proposal is made for calculating their production as well as for sphaerids and P. affinis. Sampling is expected to continue at least through March 1974 to give a full year's data. In the near future the results of this study are to be correlated with studies concerning primary production, fish feeding habits, lake sedimentation rates, and physical properties. Title: Benthic macroinvertebrate production Author: Bissonnette, Pam, Taub, F. B. (Frieda B.), University of Washington, U.S. International Biological Program. Coniferous Forest Biome Macroinvertebrates were sampled on a regular basis from March to October 1973. A relationship between chironomid length and biomass was established. Production equations to be used for these insects are reported. A similar length/weight relationship is presently being explored for the oligochaetes. A proposal is made for calculating their production as well as for sphaerids and P. affinis. Sampling is expected to continue at least through March 1974 to give a full year's data. In the near future the results of this study are to be correlated with studies concerning primary production, fish feeding habits, lake sedimentation rates, and physical properties. Close