dynamics this index in the deepwater area has no permanent peak in winter. The
marked increase in primary production can be traced only in extremely cold
winters, when its value can be four times higher than in summer.
Largest monthly flows of inorganic phosphorus income (bottom-up and regeneration fluxes) seasonal variation in primary production has been calculated, which
could potentially be synthesized based on them. Recalculation of flows carbon units
carried out according to the ratio Redfield 106:16:1 based on seasonal changes in
the contribution of bacteria into total consumption of phosphate (phytoplankton,
bacteria) by microplankton in photic layer (Parkhomenko 2009). The values
obtained were compared with the averaged on the same scale data long-term
experimental studies carried out using the isotope
14 C (Fig. 19.5). It is evident
that the seasonal variability of the calculated values is in the variability of boundaries experimentally obtained monthly primary production values, and for most of
the year, our estimates are within the range of variability. In January–March, they
are closer to the minimum values of primary production, which seems quite logical,
since we have taken in the calculation of the value K Z for the winter months more in
line with a moderate climate condition.
Obviously, higher productivity is typical for the harsh winters. Therefore, there
was the highest value of primary production in February and March (from experimental data) can be attributed mainly growth of the “new” product, which is
synthesized from the income of nutrients from deep layers. The difference between
the minimum and maximum average monthly primary production estimates in
February–March is about 100%, or 300–400 mgCm
À2 day
À1 (Fig. 19.5). If we
assume that the value of the F P , which is equal to 50–70%, corresponding to the
terms of the warm winter, the “new” production in extremely cold winters may by
increased by 2–3 times, and its contribution to overall primary synthesis may
reach 70–85%. According to our calculations, the value of the annual primary
production, which can be synthesized based on the upward and regeneration fluxes
phosphate was 120 gCm
À2 year
À1 , which is comparable with the estimates of this
parameter from measurements in situ – 110 gCm
À2 year
À1 (Demidov 2008),
130 gCm
À2 year
À1 , (Stelmakh et al. 1998) and 137 gCm
À2 year
À1 (Vedernikov
and Demidov 1997). Value calculated and experimentally derived primary production of monthly and annual average estimates means that the calculated rate of
inorganic phosphorus income the zone of photosynthesis due to the upward and
regeneration fluxes throughout the year is enough primary production level
observed in the deepwater area of the Black Sea.
19 Phosphorus Fluxes in the Pelagic Zone of the Black Sea
345
marked increase in primary production can be traced only in extremely cold
winters, when its value can be four times higher than in summer.
Largest monthly flows of inorganic phosphorus income (bottom-up and regeneration fluxes) seasonal variation in primary production has been calculated, which
could potentially be synthesized based on them. Recalculation of flows carbon units
carried out according to the ratio Redfield 106:16:1 based on seasonal changes in
the contribution of bacteria into total consumption of phosphate (phytoplankton,
bacteria) by microplankton in photic layer (Parkhomenko 2009). The values
obtained were compared with the averaged on the same scale data long-term
experimental studies carried out using the isotope
14 C (Fig. 19.5). It is evident
that the seasonal variability of the calculated values is in the variability of boundaries experimentally obtained monthly primary production values, and for most of
the year, our estimates are within the range of variability. In January–March, they
are closer to the minimum values of primary production, which seems quite logical,
since we have taken in the calculation of the value K Z for the winter months more in
line with a moderate climate condition.
Obviously, higher productivity is typical for the harsh winters. Therefore, there
was the highest value of primary production in February and March (from experimental data) can be attributed mainly growth of the “new” product, which is
synthesized from the income of nutrients from deep layers. The difference between
the minimum and maximum average monthly primary production estimates in
February–March is about 100%, or 300–400 mgCm
À2 day
À1 (Fig. 19.5). If we
assume that the value of the F P , which is equal to 50–70%, corresponding to the
terms of the warm winter, the “new” production in extremely cold winters may by
increased by 2–3 times, and its contribution to overall primary synthesis may
reach 70–85%. According to our calculations, the value of the annual primary
production, which can be synthesized based on the upward and regeneration fluxes
phosphate was 120 gCm
À2 year
À1 , which is comparable with the estimates of this
parameter from measurements in situ – 110 gCm
À2 year
À1 (Demidov 2008),
130 gCm
À2 year
À1 , (Stelmakh et al. 1998) and 137 gCm
À2 year
À1 (Vedernikov
and Demidov 1997). Value calculated and experimentally derived primary production of monthly and annual average estimates means that the calculated rate of
inorganic phosphorus income the zone of photosynthesis due to the upward and
regeneration fluxes throughout the year is enough primary production level
observed in the deepwater area of the Black Sea.
19 Phosphorus Fluxes in the Pelagic Zone of the Black Sea
345