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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Forest, Animal, And Seasonal Cycles Observed In Vernal Ponds At Audubon Center, Michael Link
Forest, Animal, And Seasonal Cycles Observed In Vernal Ponds At Audubon Center, Michael Link
Journal of the Minnesota Academy of Science
Observations of environmental conditions and biota in four depressed spots, called "vernal ponds", within the Northwoods Audubon Center near Sandstone, Minnesota, are reported for the period March 15 to September 4, 1977. Life cycle dynamics and utilization of the pond areas are considered in relation to time, days of the month, moisture-dryness, and species; but are lumped together for reporting as if the four locations were a single pond entity. Hypotheses as to the role of these ponds in the surrounding ecosystem and questions for possible further investigation are suggested.
Acid Rains: Implications For Agriculture, Prabhu D. Rawate
Acid Rains: Implications For Agriculture, Prabhu D. Rawate
Journal of the Minnesota Academy of Science
No abstract provided.
A Comparative Water Quality Study Of Man-Made Drainage And Natural Streams, Kent W. Boyum
A Comparative Water Quality Study Of Man-Made Drainage And Natural Streams, Kent W. Boyum
Journal of the Minnesota Academy of Science
The effects of man-made drainage systems on the water quality of receiving bodies Is relatively unknown. During the ice-free season of 1979, thirteen drainage ditches and f our rivers were sampled at intervals of three to eight days. With increasing flow, total orthophosphatephosphorous, total Kjeldahl-nitrogen, nitrate-nitrogen and total dissolved solids increased, but not proportionately to f low, with total orthophosphate-phosphorous showing the least proportionality. Variation was observed in each ditch and river when broken down seasonally for each parameter. Generally, when the percentage of flow was greater in one of the three seasons, the percentage of each of the other …
Land-Cover Changes In A River Valley In Blue Earth County, Minnesota, 1938-1974, Corrie Schaffer Cowley
Land-Cover Changes In A River Valley In Blue Earth County, Minnesota, 1938-1974, Corrie Schaffer Cowley
Journal of the Minnesota Academy of Science
The boundary of the Blue Earth River Valley was determined by stereoscopic viewing of 1938-39 aerial photographs. The same boundary was then drawn on corresponding 1974 photographs. All area within the river valley was assigned to one of four land-cover. Comparison of 1938-39 to 1974 shows a decrease of 19 percent in river area, an increase of one percent in row crop area, an increase of 52 percent in tree area, and a decrease of 45 percent in scrub area.
A Survey Of Water Flow In Drainage Ditches And Streams In South Central Minnesota, Clay Pierce, Bill Thompson
A Survey Of Water Flow In Drainage Ditches And Streams In South Central Minnesota, Clay Pierce, Bill Thompson
Journal of the Minnesota Academy of Science
Discharge was monitored on 13 agricultural drainage ditches and 4 small rivers in south central Minnesota. Derived data were categorized by response to hydrologic events and stream order. Stream order was found to be the most reliable predictor of hydrologic event response. Peak flows in drainage ditches were found to correspond to peak flows in rivers.