Geology topics

Kurt P. Kowalski

Publications and source records attributed to Kurt P. Kowalski.

57 records · Page 4Linked to original sources

USGS2006

A broadscale fish-habitat model development process: Genesee Basin, New York

We describe a methodology for developing species-habitat models using available fish and stream habitat data from New York State, focusing on the Genesee basin. Electrofishing data from the New York Department of Environmental Conservation were standardized and used for model development and testing. Four types of predictive models (multiple linear regression, stepwise multiple linear regression, linear discriminant analysis, and neural network) were developed and compared for 11 fish species. Predictive models used as many as 25 habitat variables and explained 35-91% of observed species abundance variability. Omission rates were generally low, but commission rates varied widely. Neural network models performed best for all species, except for rainbow trout Oncorhynchus mykiss , gizzard shad Dorosoma cepedianum , and brown trout Salmo trutta . Linear discriminant functions generally performed poorly. The species-environment models we constructed performed well and have potential applications to management issues.

Book chapter↗

USGS2003

Differences in sedge fen vegetation upstream and downstream from a managed impoundment

The U.S. Fish and Wildlife Service proposed the restoration of wetlands impacted by a series of drainage ditches and pools located in an extensive undeveloped peatland in the Seney National Wildlife Refuge, Michigan. This study examined the nature and extent of degradation to the Marsh Creek wetlands caused by alteration of natural hydrology by a water-storage pool (C-3 Pool) that intersects the Marsh Creek channel. We tested the hypothesis that a reduction in moderate-intensity disturbance associated with natural water-level fluctuations below the C-3 dike contributed to lower species richness, reduced floristic quality and a larger tree and shrub component than vegetation upstream from the pool. Wetland plant communities were sampled quantitatively and analyzed for species richness, floristic quality and physiognomy. Aerial photographs, GIS databases and GPS data contributed to the characterization and analysis of the Marsh Creek wetlands. Results showed that there was lower species richness in vegetated areas downstream from the pool, but not the anticipated growth in shrubs. Wetland vegetation upstream and downstream from the pool had similar floristic quality, except for a greater number of weedy taxa above the pool. Seepage through the pool dike and localized ground-water discharge created conditions very similar to those observed around beaver dams in Marsh Creek. In essence, the dike containing the C-3 Pool affected hydrology and wetland plant communities in a manner similar to an enormous beaver dam, except that it did not allow seasonal flooding episodes to occur. Management actions to release water from the pool into the original Marsh Creek channel at certain times and in certain amounts that mimic the natural flow regime would be expected to promote greater plant species richness and minimize the negative impacts of the dike.

American Midland Naturalist↗

USGS1999

Use of historical and geospatial data to guide the restoration of a Lake Erie coastal marsh

Historical and geospatial data were used to identify the relationships between water levels, wetland vegetation, littoral drift of sediments, and the condition of a protective barrier beach at Metzger Marsh, a coastal wetland in western Lake Erie, to enhance and guide a joint federal and state wetland restoration project. Eleven sets of large-scale aerial photographs dating from 1940 through 1994 were interpreted to delineate major vegetation types and boundaries of the barrier beach. A geographic information system (GIS) was then used to digitize the data and calculate the vegetated area and length of barrier beach. Supplemented by paleoecological and sedimentological analyses, aerial photographic interpretation revealed that Metzger Marsh was once a drowned-river-mouth wetland dominated by sedges and protected by a sand barrier beach. Extremely high water levels, storm events, and reduction of sediments in the littoral drift contributed to the complete destruction of the barrier beach in 1973 and prevented its recovery. The extent of wetland vegetation, correlated to water levels and condition of the barrier beach, decreased from a high of 108 ha in 1940 to a low of 33 ha in 1994. The lack of an adequate sediment supply and low probability of a period of extremely low lake levels in the near future made natural reestablishment of the barrier beach and wetland vegetation unlikely. Therefore, the federal and state managers chose to construct a dike to replace the protective barrier beach. Recommendations stemming from this historical analysis, however, resulted in the incorporation of a water-control structure in the dike that will retain a hydrologic connection between wetland and lake. Management of the wetland will seek to mimic processes natural to the wetland type identified by this analysis.

Wetlands↗