Growth rate variation in the N:P requirement ratio of phytoplankton
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1040 E. Biological Oceanography OLR (1985) 32 (12) 425-450 nm, a broad shoulder to 550 nm, a valley from 600 to 650 nm and a rise at 675 rim. The error resulting from the use of spectrally averaged initial slope to predict photosynthesis under different optical and fluid dynamical conditions at sea is discussed. Bedford Inst. of Oceanogr., Dartmouth, NS B2Y 4A2, Canada. 85:7222 Maclsaac, J.J., R.C. Dugdale, R.T. Barber, D. Blasco and T.T. Packard, 1985. Primary pro- duetton cycle in an uim,elllag center [Peru coast, 15°S]. Deep-Sea Res., 32(5A):503-529. Four zones of physiological condition were distin- guished along the axis of the upwelling plume. In Zone I phytoplankton upwelled with nutrient-rich water were initially 'shifted-down'; in Zone II they underwent light-induced 'shift-up' to increased nutrient uptake, photosynthesis, and synthesis of macromolecules. In Zone III ambient nutrient concentrations were rapidly reduced, there was a rapid accumulation of phytoplankton biomass, and processes proceeded at maximal rates. In Zone IV ambient nutrient concentrations were significantly decreased, phytoplankton biomass remained high, and limitation of processes was beginning. The cycle from initial upwelling to 'shift-down' was completed in 8 to 10 days within 30 to 60 km off the coast. Dugdale: Dept. of Biol. Sei., Allen Hancock Fnd.. Univ. of So. Calif., Los Angeles. CA 90007, USA. 85:7223 Palmisano, A.C. and C.W. Sullivan, 1985. Pathways of ~ carbon ~ in ~4ce from McMm, do Stand, Antarctica. Limnol. Oceanogr., 30(3):674-678. Although sea-ice microalgae share a low tempera- ture, ice-associated environment, their patterns of z4C assimilation into proteins, polysaecharides. lipids, and small molecular weight metabolites suggest that the physiological ecology of surface, bottom congelation, and platelet ice communities should be considered separately. Allan Hancock Fnd., Univ. of So. Calif.. Los Angeles, CA 90089, USA. 85:7224 Percy, J.A. and F.J. Fife, 1985. ~ ~ i o Arctic, 38(1):39-42. In the upper 50 m of the water column three species (Mertensia ovum, Sagitta elegans, and Parathemisto libellula) consistently accounted for 90% of the caloric content of the macrozooplankton commu- nity. The ctenophore dominated the samples and accounted for 60--95% of the total calories. In deeper water (>70 m) euphansiids, primarily Thysanoessa inerm~s, accounted for most of the macrozooplank- ton calories. Ctenophores do not appear to be major prey of arctic marine vertebrates; thus in Frobisher Bay surface waters a large proportion of the available energy ends up in an apparent trophic dead end and the ctenophores' precise role in the ecosys- tem is unclear. Arctic Biol. Sta., Dept. of Fish. and Oceans, 555 St. Pierre Blvd., Ste. Anne de Bellevue. PQ H9X 3R4. Canada. 85:7225 Terry, K.L., E.A, Laws and D.J. Burns, 1985. Growth rate varlatlea in the N:P reqldrmtent ratio of phytol~maktoa. J. Phycol., 21(2):323-329. The prediction that the cell N:P ratio at transition from N-limitation to P-limitation of phytoplankton growth (critical ratio, R0 vanes as a function of population growth rate is confirmed. R~ passes through a maximum at intermediate growth rates for the three species for which data are available, but there is significant interspecific variability in its value. There is no evidence to support the idea that the ratio of subsistence N and P cell quotas is equal to R c over the range of growth rates, or that the subsistence quota ratio equals the ratio of the N and P cell quotas minus a storage fraction. N:P com- position ratios can be used to determine which nutrient is limiting, but not to determine relative growth rates or competitive advantage between species limited by the same nutrient. Growth rates are determined by environmental conditions and by the cell quota of the limiting nutrient, without reference to the cell quota of the nonqimiting nutrient. Solar Energy Res. Inst., 1617 Cole Blvd.. Golden, CO 80401, USA. 85:7226 Vegter, F. and P.R.M. De Visscher, 1984. Phyto- i~Ju L~wy ~ ~ ~ Lake C,r~al~ (SW N ~ ) ~ 197~ 1981. Neth. J. Sea Res, 18(3-4):246-259. After a sluice between the lake and the North Sea was opened in 1978, primary production increased from 90 to 225 g C m -2 y-n in 1981. Increased nitrate concentrations may have enhanced production. At the end of February of almost every year primary production was triggered when light conditions of 0.002-0.004 J cm -2 s-' prevailed in the water column. Delta Inst. for Hydrobiol. Res., Vierstraat 28, 4401 EA, Netherlands. (mwO 85:7227 Vegter, F. and P.R.M. De Visscher, 1984. Extra- celll~ r ~ by playtop~ dWf~ pho-
Transcript of Growth rate variation in the N:P requirement ratio of phytoplankton
1040 E. Biological Oceanography OLR (1985) 32 (12)
425-450 nm, a broad shoulder to 550 nm, a valley from 600 to 650 nm and a rise at 675 rim. The error resulting from the use of spectrally averaged initial slope to predict photosynthesis under different optical and fluid dynamical conditions at sea is discussed. Bedford Inst. of Oceanogr., Dartmouth, NS B2Y 4A2, Canada.
85:7222 Maclsaac, J.J., R.C. Dugdale, R.T. Barber, D.
Blasco and T.T. Packard, 1985. Primary pro- duetton cycle in an uim,elllag center [Peru coast, 15°S]. Deep-Sea Res., 32(5A):503-529.
Four zones of physiological condition were distin- guished along the axis of the upwelling plume. In Zone I phytoplankton upwelled with nutrient-rich water were initially 'shifted-down'; in Zone II they underwent light-induced 'shift-up' to increased nutrient uptake, photosynthesis, and synthesis of macromolecules. In Zone III ambient nutrient concentrations were rapidly reduced, there was a rapid accumulation of phytoplankton biomass, and processes proceeded at maximal rates. In Zone IV ambient nutrient concentrations were significantly decreased, phytoplankton biomass remained high, and limitation of processes was beginning. The cycle from initial upwelling to 'shift-down' was completed in 8 to 10 days within 30 to 60 km off the coast. Dugdale: Dept. of Biol. Sei., Allen Hancock Fnd.. Univ. of So. Calif., Los Angeles. CA 90007, USA.
85:7223 Palmisano, A.C. and C.W. Sullivan, 1985. Pathways
of ~ carbon ~ in ~ 4 c e from McMm, do Stand, Antarctica.
Limnol. Oceanogr., 30(3):674-678.
Although sea-ice microalgae share a low tempera- ture, ice-associated environment, their patterns of z4C assimilation into proteins, polysaecharides. lipids, and small molecular weight metabolites suggest that the physiological ecology of surface, bottom congelation, and platelet ice communities should be considered separately. Allan Hancock Fnd., Univ. of So. Calif.. Los Angeles, CA 90089, USA.
85:7224 Percy, J.A. and F.J. Fife, 1985. ~ ~ i o
Arctic, 38(1):39-42.
In the upper 50 m of the water column three species (Mertensia ovum, Sagitta elegans, and Parathemisto libellula) consistently accounted for 90% of the caloric content of the macrozooplankton commu- nity. The ctenophore dominated the samples and
accounted for 60--95% of the total calories. In deeper water (>70 m) euphansiids, primarily Thysanoessa inerm~s, accounted for most of the macrozooplank- ton calories. Ctenophores do not appear to be major prey of arctic marine vertebrates; thus in Frobisher Bay surface waters a large proportion of the available energy ends up in an apparent trophic dead end and the ctenophores' precise role in the ecosys- tem is unclear. Arctic Biol. Sta., Dept. of Fish. and Oceans, 555 St. Pierre Blvd., Ste. Anne de Bellevue. PQ H9X 3R4. Canada.
85:7225 Terry, K.L., E.A, Laws and D.J. Burns, 1985. Growth
rate varlatlea in the N:P reqldrmtent ratio of phytol~maktoa. J. Phycol., 21(2):323-329.
The prediction that the cell N:P ratio at transition from N-limitation to P-limitation of phytoplankton growth (critical ratio, R 0 vanes as a function of population growth rate is confirmed. R~ passes through a maximum at intermediate growth rates for the three species for which data are available, but there is significant interspecific variability in its value. There is no evidence to support the idea that the ratio of subsistence N and P cell quotas is equal to R c over the range of growth rates, or that the subsistence quota ratio equals the ratio of the N and P cell quotas minus a storage fraction. N:P com- position ratios can be used to determine which nutrient is limiting, but not to determine relative growth rates or competitive advantage between species limited by the same nutrient. Growth rates are determined by environmental conditions and by the cell quota of the limiting nutrient, without reference to the cell quota of the nonqimiting nutrient. Solar Energy Res. Inst., 1617 Cole Blvd.. Golden, CO 80401, USA.
85:7226 Vegter, F. and P.R.M. De Visscher, 1984. Phyto-
i ~ J u L ~ w y ~ ~ ~ Lake C , r ~ a l ~ (SW N ~ ) ~ 197~ 1981. Neth. J. Sea Res, 18(3-4):246-259.
After a sluice between the lake and the North Sea was opened in 1978, primary production increased from 90 to 225 g C m -2 y-n in 1981. Increased nitrate concentrations may have enhanced production. At the end of February of almost every year primary production was triggered when light conditions of 0.002-0.004 J cm -2 s-' prevailed in the water column. Delta Inst. for Hydrobiol. Res., Vierstraat 28, 4401 EA, Netherlands. (mwO
85:7227 Vegter, F. and P.R.M. De Visscher, 1984. Extra-
c e l l l ~ r ~ by p l a y t o p ~ dWf~ pho-
