The Calcium, Magnesium, Potassium, and Sodium Budgets for a Small Forested Ecosystem

Abstract

The balance of calcium, magnesium, potassium, and sodium was studied in six watersheds of the Hubbard Brook Experimental Forest at West Thornton, New Hampshire. These watersheds are characterized by a near climax, northern hardwoods ecosystem, humid continental climate, and acid metamorphic rock. Bedrock in the area is considered to be watertight. Weekly samples of precipitation and stream water were collected from June 1963 through May 1965. Cation analyses were made by atomic absorption spectrophotometry. Precipitation was about 117 em during 1963-64 and 95 em during 1964-65 and did not differ significantly in amount with elevation. Loss of water by runoff from the system was about 68 em during 1963-64 and 49 em during 1964-65. Evapotranspirational losses were calculated at 49 em in 1963-64 and 46 em in 1964-65. About 37% of the total annual runoff occurred in April and less than 0.2% in September. Concentration of Ca++, Mg++, K+, and Na+ in weekly precipitation samples was variable. The annual weighted average values (mg/liter) were: 1963-64, Ca 0.26, Mg 0.06, K 0.21, Na 0.09; 1964-65, Ca 0.30, Mg 0.12, K 0.19, Na 0.22. Differences were not related to elevation. The contribution of cations from dry fallout was negligible. Cation content of stream water was relatively very low. The weighted average content for the entire area (mg/liter) was Ca 1.18, Mg 0.38, K 0.26, Na 0.87 during 1963-64; and Ca 0.80, Mg 0.38, K 0.22, Na 0.91 during 1964-65.In general, the cationic concentrations in drainage water were constant although discharge of water varied greatly. Statistically, the relationship between concentration and discharge was not significant for Ca + + and Mg+ + in any of the watersheds, but was inversely significant for N a+, and was possibly direct for K + in a few instances. The budget for dissolved cations was calculated from determinations of input (cation concentration times volume of precipitation) and output (cation concentration times volume of runoff.) During 1963-64 the average inputs in kg/ha were 3.0 Ca++, 0.7 Mg++, 2.5 K+, and 1.0 Na+, while the output averaged 8.0 Ca++, 2.6 Mg++, 1.8 K+, and 5.9 Na+. During 1964-65 the values were: input, 2.8 Ca++, 1.1 Mg++, 1.8 K+, and 2.1 Na+; and output, 3.9 Ca++, 1.8 Mg++, 1.1 K+, and 4.5 Na+. Assuming that the vegetation is near dynamic equilibrium, the net losses of Ca + +, Mg + +, and N a+ represent conservative measurements of geochemical weathering in the system. The K + budget is probably near balance.1 Financial support was provided by the N a tiona! Science Foundation (Grants No. GB 1144 and GB 4169). We acknowledge and appreciate assistance from G. Furnival with statistical analyses. We are grateful to J. Brown and P. Hoekstra for critical comments and suggestions during the preparation of this manuscript. This is contribution No.Abstract. The hypothesis that variation in dates of the beginning and end of growing seasons of eastern cottonwood (Populus deltoides Bartr.) and American sycamore (Platanus occidentalis L.) can be attributed to variation in...

Periphyton Production in an Appalachian Mountain Trout Stream

“…Smaller streams may literally feed larger streams and lakes. They also act as primary mechanisms of nutrient removal from their watershed ecosystems (Likens et al 1967, Woodall and Wallace 1975, Monk et al 1977. Therefore low order streams predispose major nutrient and energy aspects of higher order systems (Hynes 1975).…”

Chemistry of precipitation, streamwater, and lakewater from the Hubbard Brook Ecosystem Study: a record of sampling protocols and analytical procedures

“…These data were reported in Likens et al (1967), though these authors noted the potential for underestimation of these base cations and already had begun rectifying the apparent discrepancy. The results of base-cation analyses with and without lanthanum were reported in Johnson et al (1968) and Likens et al (1967) Subsequently, calcium data for weekly streamwater samples from June 1963 to December 1965 were adjusted upward 1.6-fold in the data files (printed copies of the original analytical summary sheets are on file). Lanthanum has been used in FAAS analyses for calcium and magnesium since January 1966.…”

“…Precipitation is collected weekly with bulk collectors , that is, collectors that are continuously open to the atmosphere. During the warmer months, approximately 1 May to 1 November, rainfall is collected using HDPE funnels connected to LDPE bottles with laboratory-grade polyvinyl (Tygon) 1 tubing and various polypropylene, polyethylene, or nylon fittings (see Figure 2 in Likens et al 1967). Individual plastic pieces of the collection system are replaced at least every 3 years.…”

“…Johnson et al 1968;Likens et al 1967), we entered data on punch-tape terminals in batches of cations or anions for separate watersheds and single years, and used programs written in Basic on a mainframe computer at Dartmouth College to calculate daily and monthly inputs/outputs. The calculated values were stored as computer printouts.…”

Interactions between macroinvertebrate taxa and complex environmental gradients influencing abundance and distribution in the Umatilla River, Northeastern Oregon

“…In the lower Umatilla River, where the river flows through semi-arid desert, there is a shift in agriculture to irrigated cropping which creates point-source fluctuations at return flow locations. As with turbidity, removal of riparian vegetation may increase the input of solutes to adjacent streams as they are less likely to be taken up by plants (Likens et al 1967). Increase in suspended solutes has also been associated with overall decreased habitat quality and negatively affects abundance, drift, and emergence of aquatic invertebrates (Allan 2004;Mesa 2009).…”