Nutrient Supply and Primary Production in Clear Lake, Eastern Ontario
01 Nov 1970-Wsq: Women's Studies Quarterly (NRC Research Press Ottawa, Canada)-Vol. 27, Iss: 11, pp 2009-2036
TL;DR: Clear Lake, a small Canadian Shield lake that has been influenced little by human activity, was found to be more productive than expected from chemical and optical properties and geological surroundings, although most of the sodium, potassium, and silica entering the lake is weathered from the terrestrial watershed.
Abstract: Clear Lake, a small Canadian Shield lake that has been influenced little by human activity, was found to be more productive than expected from chemical and optical properties and geological surroun...
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TL;DR: In this article, data for summer chlorophyll and spring total phosphorus concentration were collected from 19 lakes in southern Ontario and combined with data reported in the literature for other North American lakes to produce a regression line that can be used to predict the average summer CHP from a single measurement of phosphorus concentration at spring overturn.
Abstract: Data for summer chlorophyll and spring total phosphorus concentration were collected from 19 lakes in southern Ontario and combined with data reported in the literature for other North American lakes to produce a regression line that can be used to predict the average summer chlorophyll concentration from a single measurement of phosphorus concentration at spring overturn. This equation is not significantly different from a previously published phosphorus-chlorophyll relationship derived for a number of Japanese lakes.
1,135 citations
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01 Mar 1975
TL;DR: In this paper, mass balance and export models are explored in relation to eutrophication as caused by phosphorus and nitrogen in lakes and it is shown that lakes having long water renewal times are much more sensitive to phosphorus loading than would appear from mean depth only.
Abstract: Elementary mass balance and export models are explored in relation to eutrophication as caused by phosphorus and nitrogen. New criteria for phosphorus loading are given in relation to the ratio ‘mean depth-water fill-in-time’
$$(\bar z/\tau _w )$$
. The results suggest that lakes having long water renewal times are much more sensitive to phosphorus loading than would appear from mean depth only. Further, from comparison of the relative residence time of nitrogen and phosphorus, it is deduced that—with increasing eutrophication—the nitrogen metabolism is speeded up beyond the point of simple proportionality which would explain the transition from phosphorus to nitrogen limitation in highly eutrophied lakes. It is further suggested that the principles derived from eutrophication in regard to the metabolism of phosphorus and nitrogen in lakes are applicable also to other environmental compartments and stress factors.
735 citations
TL;DR: In this paper, the export of total phosphorus from 34 watersheds in Southern Ontario was measured over a 20-month period, and the average export was 48 mg m−2 yr−1, significantly different from the average (110 mgm−2 yr−1) for watersheds that included pasture as well as forest.
395 citations
TL;DR: In this article, the authors consider some of the ecological interactions and linkages that occur between land and water, and show the need for a comprehensive understanding of the intricate and complicated interactions.
Abstract: prehending the implications of this disposal downstream. The implications of this are more and more evident in the widespread cultural eutrophication of rivers and lakes. Attempts to understand these problems have been based upon information pieced together from separate (independent) aquatic and terrestrial studies. This ignores important linkages, is inadequate, and shows the need for a comprehensive understanding of the intricate and complicated interactions between land and water. The purpose of this paper, then, is to consider some of the ecological interactions and linkages that occur between
347 citations
TL;DR: In this paper, the impact of soil and fertilizer phosphorus on the environment is described and an increase in the amounts of soluble and particulate P transported in surface runoff have been measured after the application of fertilizer P. The detachment and transport of particulate phosphorus is also elaborated.
Abstract: Publisher Summary This chapter describes the impact of soil and fertilizer phosphorus on the environment. Phosphorus in the form of phosphate (P) is essential for plant growth and its application to agricultural land often improves crop production. Production per unit area is increased with fertilizer P. The increased plant cover that is possible with proper use of fertilizer can reduce soil erosion from the cultivated area. Addition of phosphorus to fish ponds may also increase fish production. Potentially toxic chemical elements may be introduced into the food chain by adding P fertilizer to the soil. Increase in the amounts of soluble and particulate P transported in surface runoff have been measured after the application of fertilizer P. Phosphorus losses in surface runoff may be reduced by incorporating fertilizer material into the surface soil, away from the zone of extraction and detachment, and by using conservation or minimum tillage methods to reduce soil erosion. The detachment and transport of particulate phosphorus is also elaborated.
216 citations
References
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TL;DR: In this article, the authors show that during the summer, biologic activity measurably reduces the concentration of nitrate and potassium in stream water, while hydrogen ion, aluminum, and nitrate concentrations are increased.
Abstract: Stream water chemistry varies hyperbolically with stream discharge through four decades of discharge change within the Hubbard Brook Experimental Forest, New Hampshire. This dilution process is most simply explained by the mixing of rain water or surface water with deeper soil water. The resultant mixture of waters subsequently appears as stream water. Sodium and silica concentrations in stream water are markedly diluted during high discharge periods while hydrogen ion, aluminum, and nitrate concentrations are increased. Magnesium, calcium, sulfate, chloride and potassium concentrations are changed very little by stream discharge variations. During the summer, biologic activity measurably reduces the concentration of nitrate and potassium in stream water. 19 references, 4 figures, 5 tables.
360 citations
TL;DR: The forest of a small watershed-ecosystem was cut in order to determine the effects of removal of vegetation on nutrient cycles, and the cut ecosystem exhibited accelerated loss of nutrients.
Abstract: The forest of a small watershed-ecosystem was cut in order to determine the effects of removal of vegetation on nutrient cycles. Relative to undisturbed ecosystems, the cut ecosystem exhibited accelerated loss of nutrients: nitrogen lost during the first year after cutting was equivalent to the amount annually turned over in an undisturbed system, and losses of cations were 3 to 20 times greater than from comparable undisturbed systems. Possible causes of the pattern of nutrient loss from the cut ecosystem are discussed.
263 citations
TL;DR: The nitrate concentration (weighted average) in stream water from an experimentally deforested watershed increased from 0.9 milligram per liter before removal of the vegetation to 53 milligrams per liter 2 years later.
Abstract: The nitrate concentration (weighted average) in stream water from an experimentally deforested watershed increased from 0.9 milligram per liter before removal of the vegetation to 53 milligrams per liter 2 years later. This nitrate mobilization, presumably due to increased microbial nitrification, was equivalent to all of the other net cationic increases and anionic decreases observed in tae drainage water.
241 citations
TL;DR: In this article, the losses of dissolved Ca, Na, Mg and K have been determined for six small watersheds in New Hampshire during the period 1963-1967, from the rate at which Ca and Na are lost, the steady-state chemical weathering rate is calculated at 800 kg of bedrock-till per hectare per year.
165 citations
151 citations