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D. Soto and J.G. Stockner
'GlOO
OJ
.a
.c
o
o
0
o 0
o 0
10
O j O - f - - - - - - - - - - - - - - - f - -
1
Figure 13.3. Annu al average total phosphorus (TP) vs chlorophyll (CHL) relationship in several sites with different TP loadings in Lake Llanquihue, Chile.
aI., 1993). Such severe N-limitation would slow the onset of eutrophication
in these lakes. BC lakes commonly show periods of colimitation when
both P and N levels are so low as to be growth limiting (Suttle, Cochlan,
& Stockner , 1991). The TP: CHL relationship for N-limited Chilean lakes
has a lower functional slope value (1.05) than colimited BC lakes (1.21)
and a much lower value than P-limited north temperate lakes (Figure
13.4, Table 13.2). Nitrogen-fixing colonial cyanobacteria which can occur
in more product ive meso- or eutrophic N-limited lakes rarely occur in
Chilean or BC lakes. This is because of very low (subthreshold) ambient
concentrations of P that limit the growth of larger colonial cyanobacteria
(Spencer & King, 1985; Stockner & Shortreed, 1988).
CHILEAN TEMPERATE LAKES (e)
10
Figure 13.4. Annual average total phosphorus (TP) vs chlorophyll (CHL) relation -
ships in Chilean and British Columbia! lakes. efrom Stockner & Shortreed,
1985).