Faculty Opinions recommendation of Iron constraints on planktonic primary production in oligotrophic lakes.

The precision of the Winkler method can reach 2 µg ·L-1 if a potentiometric end-point detection method if used and if minor modifications to standard protocols are made. The major sources of variability encountered at this precision level are due to the gradual decrease (1-3 µg ·L-1 ·h-1) in apparent O2 which occurs after reagent addition and to thermal expansion and contraction of the samples during storage. These sources of error can, however, be easily minimized or eliminated. The precision of the proposed protocols for Winkler determinations and metabolic rate measurements allows the detection of gross primary production and community respiration rates as low as 0.7 mg C ·m-3 ·h-1 after 4-h incubations. The methods are therefore adequate for metabolic studies in oligotrophic lakes, where epilimnetic production and respiration rates range between 5 and 50 mg C ·m-3 ·h-1.

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Limnological Conditions in Five Small Oligotrophic Lakes in Terra Nova National Park, Newfoundland

Journal of the Fisheries Research Board of Canada ◽

10.1139/f74-091 ◽

1974 ◽

Vol 31 (5) ◽

pp. 555-583 ◽

Cited By ~ 25

Author(s):

Joseph J. Kerekes

Keyword(s):

Primary Production ◽

Total Phosphorus ◽

National Park ◽

Phosphorus Concentration ◽

Water Color ◽

Oligotrophic Lakes ◽

Water Renewal ◽

Renewal Rate ◽

Catchment Areas ◽

Terra Nova

Five oligotrophic lakes in Terra Nova National Park, Newfoundland, varying in mean depth (1.06–9.22 m), in water renewal rate (0.2–20.7 times per annum), in salinity (18.2–42.6 mg/liter), in total phosphorus (0.1–0.6 mg-at P/m3), and in chlorophyll a concentration (0.5–3.2 mg/m3), were investigated for 17 mo in 1969 and 1970. Hypolimnetic oxygen deficits ranged between 111 and 217 mg O2 per m2/day. Low levels of nutrients, reduced solar radiation, and low underwater light penetration, owing to excessive cloudiness and high water color, seriously limited planktonic primary production. The relation between primary production at optimum light, and water renewal per annum, appeared to be curvilinear when the rate of primary production began to decline above an optimum water renewal rate. The seasonal and annual variations in water color and salinity were dependent on the rate of water renewal, but other lakes on the catchment areas modified that relation. Winter road salting operations within the catchment area caused a considerable increase in salinity, total phosphorus concentration, and primary production in one lake. A new morphometric index which reflects the littoral effect on basin volume was proposed.

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Effects of Habitat-Specific Primary Production on Fish Size, Biomass, and Production in Northern Oligotrophic Lakes

Ecosystems ◽

10.1007/s10021-021-00733-6 ◽

2022 ◽

Author(s):

Sven Norman ◽

Karin A. Nilsson ◽

Marcus Klaus ◽

David Seekell ◽

Jan Karlsson ◽

...

Keyword(s):

Primary Production ◽

Biomass Production ◽

Brown Trout ◽

Gross Primary Production ◽

Maximum Size ◽

Arctic Char ◽

Relative Distribution ◽

Oligotrophic Lakes ◽

Benthic Primary Production ◽

Fish Size

AbstractEcological theory predicts that the relative distribution of primary production across habitats influence fish size structure and biomass production. In this study, we assessed individual, population, and community-level consequences for brown trout (Salmo trutta) and Arctic char (Salvelinus alpinus) of variation in estimated habitat specific (benthic and pelagic) and total whole lake (GPPwhole) gross primary production in 27 northern oligotrophic lakes. We found that higher contribution of benthic primary production to GPPwhole was associated with higher community biomass and larger maximum and mean sizes of fish. At the population level, species-specific responses differed. Increased benthic primary production (GPPBenthic) correlated to higher population biomass of brown trout regardless of being alone or in sympatry, while Arctic char responded positively to pelagic primary production (GPPPelagic) in sympatric populations. In sympatric lakes, the maximum size of both species was positively related to both GPPBenthic and the benthic contribution to GPPWhole. In allopatric lakes, brown trout mean and maximum size and Arctic char mean size were positively related to the benthic proportion of GPPWhole. Our results highlight the importance of light-controlled benthic primary production for fish biomass production in oligotrophic northern lakes. Our results further suggest that consequences of ontogenetic asymmetry and niche shifts may cause the distribution of primary production across habitats to be more important than the total ecosystem primary production for fish size, population biomass, and production. Awareness of the relationships between light availability and asymmetric resource production favoring large fish and fish production may allow for cost-efficient and more informed management actions in northern oligotrophic lakes.

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PRESENT AND FUTURE PROSPECTS FOR FORESTRY IN THE CENTRAL PUMICE REGION

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1971.33.1301 ◽

1971 ◽

pp. 14-17

Author(s):

J. Ure

Keyword(s):

New Zealand ◽

Primary Production ◽

Future Prospects ◽

Export Markets ◽

Local Conditions

The region contains half the area of exotic forest in New Zealand and the major industries dependent thereon. Both are expanding rapidly to meet promising export markets. Local conditions are particularly favourable for this form of primary production and continued expansion is expected.

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