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Full-Text Articles in Physical Sciences and Mathematics

Effect Of Human Disturbance On Small Mammal Communities In Itasca State Park, Minnesota, Nancy L. Staus, Kathleen Conforti, Leslie N. Clapper, Jennifer A. Longhenry, C. C. Schoenbauer, Michael S. Rentz, John R. Tester Jan 1999

Effect Of Human Disturbance On Small Mammal Communities In Itasca State Park, Minnesota, Nancy L. Staus, Kathleen Conforti, Leslie N. Clapper, Jennifer A. Longhenry, C. C. Schoenbauer, Michael S. Rentz, John R. Tester

Journal of the Minnesota Academy of Science

We determined effects of different levels of human disturbance on small mammal richness and relative abundance from live-trapping data obtained in Itasca State Park in northwestern Minnesota. We developed a quantitative measure of human disturbance based on disturbance units and trapped small mammals on three study sites, each reflecting a different level of disturbance. Our data revealed that small mammal diversity decreased with increasing human disturbance. Amount of ground cover and litter depth also appeared to be important in explaining differences in the demographic patterns of small mammals among sites.


A Comparative Water Quality Study Of Man-Made Drainage And Natural Streams, Kent W. Boyum Jan 1980

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 …


Effect Of Feedlots On Water Quality, Ronald D. Cheetham, Alan J. Holmes, David Borresen Jan 1975

Effect Of Feedlots On Water Quality, Ronald D. Cheetham, Alan J. Holmes, David Borresen

Journal of the Minnesota Academy of Science

The effect of feedlot runoff on water quality was examined. Samples were collected from river feedlots and offshore from lake feedlots and compared with samples from appropriate control sites. Bacterial contamination, as measured by the total coliform test over two successive summers, exhibited significant variation between feedlot and control sites. Coliform levels at lake sites adjacent to feedlots were double the levels at control sites; while in river systems average coliform levels downstream from feedlots were approximately 17 times the upstream controls.


Pollution From Sewage Loading In River And Lakes Downstream From Bemidji, James Ludwig Jan 1972

Pollution From Sewage Loading In River And Lakes Downstream From Bemidji, James Ludwig

Journal of the Minnesota Academy of Science

The deleterious effects and downstream distribution of pollutants from domestic sewage discharged at Bemidji, Minnesota, are examined with reference lo parameters for pollution as defined by the state's Pollution Control Agency (PCA). Periodic overloading of the resort city's sewage treatment plant also is considered, along with problems pertinent to a community upstream of popular vacation facilities on a lake and river system.


A Water Quality Survey, Dale E. Mcmichael Jan 1972

A Water Quality Survey, Dale E. Mcmichael

Journal of the Minnesota Academy of Science

Representative factors influencing water quality in the Albert Lea, Minnesota area were chosen as to assess water quality and changes in the watershed which has been described as an earlier valley of the Shell Rock River.

Parameters representative of chemical, bacterial, and thermal pollution were, respectively, total phosphorous, total and fecal coliform counts, and temperature. Statistical analysis has revealed that significant differences in some parameters measured do exist when various sampling stations of a given sampling date are compared. Statistical analysis also has indicated that correlations do exist between fluctuation patterns when all sampling stations of a given sampling date …