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Full-Text Articles in Physical Sciences and Mathematics
Effects Of Fire In The Northern Great Plains, Kenneth F. Higgins, Arnold D. Kruse, James L. Piehl
Effects Of Fire In The Northern Great Plains, Kenneth F. Higgins, Arnold D. Kruse, James L. Piehl
SDSU Extension Circulars
Fire has been used inconsistently to manage native and tame grasslands in the Northern Great Plains (NGP) of the north-central U.S. and south-central Canada, particularly the grasslands found in prairies, plains, agricultural land retirement programs, and moist soil sites. This has happened for three primary reasons: (1) the reduction of American Indian use of fire after 1875, (2) fire suppression and land use changes that put increasingly more acres under annual tillage since about the same time, and (3) a growing resistance to the use of fire since about 1940, largely due to media overemphasis of its harmful effects (e.g., …
Habitat Use By Beaver Along The Big Sioux River, Charles D. Dieter
Habitat Use By Beaver Along The Big Sioux River, Charles D. Dieter
Electronic Theses and Dissertations
Habitat utilization and lodge site selection by beaver (Castor canadensis) were investigated during 1985 and 1986 along the Big Sioux River in eastern South Dakota. Because livestock grazing has affected the number and size of trees available for beaver use, the study area was portioned into grazed, ungrazed, and farmed habitat. Diameter at breast height (DBH) of trees in grazed areas was greater (p < 0.01) than in ungrazed or farmed areas. Almost half (48%) of the trees in ungrazed areas were small (DBH < 7.5 cm), while a majority (58%) of the trees in grazed areas had large diameters (DBH > 30 cm). Beaver activity was evident on 286 of 2410 (11.8%) trees (DBH > 2.5 cm) and 756 of 7,794 (9.7%) stems (DBH < 2.5cm) sampled. A greater proportion (p < 0.01) of trees were cut by beavers in ungrazed than in grazed areas. Beaver did not select tree species for cutting according to availability (p < 0.01). Green ash (Fraxinus pennsylvanica) was selected for cutting while both boxelder (Acer negundo) and hawthorn (Crataegus mollis) were selected against. Sandbar willow (Salix exigua) stems were important for food and building materials. Trees cut by beaver were significantly smaller in diameter (p < 0.01) than uncut trees. Mean distance from water of cut trees was also less (p < 0.01) than for uncut trees. Over half (52%) of the trees damaged by beaver were not killed and either resprouted or remained alive and standing. Of 8 variables examined at lodge sites, analysis indicated that the 2 most important factors in beaver lodge site selection were riverbank slope and horizontal cover density between 0.9 m and 1.8 m above ground (read from 10 m). Mean slope of the riverbank at lodge sites (40.7 degrees) was greater (p < 0.01) than at control sites (26.7 degrees), while mean horizontal cover density between 0.9 m and 1.8 m (read from 10 m) was also greater (p < 0.01) at lodge sites (53%) than at control sites (28%). Ungrazed habitat was selected by beaver for lodge sites, and grazed areas were selected against. Although 40% of the study area was ungrazed, 27 of 33 (82%) active lodges were located in these areas. Ungrazed areas along the Big Sioux River are important for beaver populations and selection for these areas by beaver reflects habitat quality.
First Year Growth And Survival Of Walleyes In Power Plant Evaporation And Holding Reservoirs, Michael P. Faler
First Year Growth And Survival Of Walleyes In Power Plant Evaporation And Holding Reservoirs, Michael P. Faler
Electronic Theses and Dissertations
Walleyes (Stizostedion vitreum) were stocked at a rate of 88 fish/hectare in two South Dakota power plant reservoirs and their growth and survival were monitored for one year. Length, weight, and survival of walleyes were significantly (P < 0.05) different between the two reservoirs. The walleyes attained a mean length of 230 mm (range 192 - 265 mm) in the Evaporation Reservoir and 205 mm (range 177-250 mm) in the Holding Reservoir. Mean weights attained by the fish were 104 g (range 65 - 165 g) in the Evaporation Reservoir and 89 g (range 48 - 135 g) in the Holding Reservoir. The growth rates of walleyes in the two reservoirs were inversely related to survival and standing crops. Walleye survival in the Evaporation Reservoir was 1.5% (0.95 C.L., 0.9 - 2.8%) with a standing crop of 0.13 kg/hectare, whereas survival in the Holding Reservoir was 17.2% (0.95 c,L., 13.5 - 22.9%) with a standing crop of 1.33 kg/ hectare. Walleye standing crop estimates, calculated in terms of weight of fish per volume of water beneath the ice, -were similar in the two reservoirs1 standing crops were 0.06 kg/1000 m3 in the Evaporation Reservoir, and 0.08 kg/1000 m3 in the Holding Reservoir. Estimated forage fish standing crops were 1 .21 kg/hectare in the Evaporation Reservoir and 1.91 kg/hectare in the Holding Reservoir.
Impacts Of Stocking Herbivorous Fishes For Aquatic Macophyte Removal Upon South Dakota Ponds, John Christopher Young
Impacts Of Stocking Herbivorous Fishes For Aquatic Macophyte Removal Upon South Dakota Ponds, John Christopher Young
Electronic Theses and Dissertations
Aquatic macrophyte removal by herbivorous fishes was investigated to determine changes in the predator-prey relationship of largemouth bass, Micropterus salmoides, and bluegills, Lepomis macrochirus, stocked into 15 prairie ponds. Monosex grass carp, Ctenopharyngodon idella, and hybrid grass carp, Ctenopharyngodon idella x Hypophthalmicthys nobilis, were each stocked at a rate of 247 fish/hectare into five study ponds. Largemouth bass and bluegills were each stocked into 12 study ponds at 247 fish/hectare in July, and 1235 fish/hectare in September, 1984, respectively. Additional largemouth bass were stocked at a rate of 247 fish/hectare into nine study ponds in July, 1985. Conductivity was the …
Habitat Selection And Sexual Suggestion Of Rocky Mountain Bighorn Sheep In Custer State Park, South Dakota, Larry J. Layne
Habitat Selection And Sexual Suggestion Of Rocky Mountain Bighorn Sheep In Custer State Park, South Dakota, Larry J. Layne
Electronic Theses and Dissertations
Spatial segregation between Rocky Mountain bighorn sheep (Ovis canadensis canadensis) ram and ewe herds has been documented by Geist (1971), Geist and Petocz (1977), Shank (1979), Morgantini and Hudson (1981), and Hogg (1983), where ram herds consist of mature males approximately 4 years old and older and ewe herds are comprised of all other individuals. Geist (1971), Shank (1979), and Hogg (1983) have shown that segregation occurs year-round except during the breeding season (November and December) when the sexes congregate on a traditional breeding range (cf. Geist 1971, p 209). These studies also have shown that the sexes remain separated …
Impact Of Grazing Systems On Rodent And Cottontail Rabbit Populations In South Texas, Meenakshi Nagendran
Impact Of Grazing Systems On Rodent And Cottontail Rabbit Populations In South Texas, Meenakshi Nagendran
Electronic Theses and Dissertations
Study sites were established at Rob and Bessie Welder Refuge and Encino Division of the King Ranch in south Texas to monitor the impact of Short-duration cell grazing (SDG) and Continuous grazing on small mammal and cottontail rabbit populations. Small mammals were live trapped (With occasional snap trapping) and cottontails were spotlighted. Vertical and horizontal components of vegetative structure were measured in terms of percent cover. There was paucity of rodents on the Welder Refuge – 8 captures for 9705 trap nights. In 1984 127 cottontails/km) and in 1985-1986 64 cottontails were seen along 436.8 km of road transects (.14 …
Evaluation Of Largemouth Bass And Bluegill Stocking Strategies In South Dakota Ponds, David M. Gilbraith
Evaluation Of Largemouth Bass And Bluegill Stocking Strategies In South Dakota Ponds, David M. Gilbraith
Electronic Theses and Dissertations
Three fish-stocking methods were evaluated to determine the effects of stocking density and chronology on largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus) survival, growth, and reproductive success during 1983-1985. Two densities of split-stocking largemouth bass with bluegills were compared to the simultaneous introduction of both species. First-year largemouth bass survival was low and variable among treatments. Survival of largemouth bass ranged from 0-85% and averaged 25% among treatments. Bluegill survival, for the first and second years combined, ranged from 0-60% and averaged 22% among two split-stocking treatments. Thirty-six percent of study ponds experienced at least partial winterkill during the …
Rainbow Trout Cage Culture Utilizing Different Strains, Stocking Densities, And Feeding Methods In Eastern South Dakota Dugout Ponds, Jay Patrick Maher
Rainbow Trout Cage Culture Utilizing Different Strains, Stocking Densities, And Feeding Methods In Eastern South Dakota Dugout Ponds, Jay Patrick Maher
Electronic Theses and Dissertations
Rainbow trout (Salmo gairdneri) cage culture techniques were investigated in dugouts as part of a continuing program to evaluate the potential of small-scale, landowner-based aquaculture operations. Trout raised in the study did not reach a marketable size (200 g) due to the short growing season and small size at stocking. No significant (P >0.05) differences in growth were detected between stocking densities of 60, 80, 100, and 120 fish/m³. Demand feeding resulted in significantly greater length (P≤0.01), weight (P≤0.01), and relative weight (P≤0.05) than hand feeding in both years tested. Rainbow trout of the Hildebrand strain reached a significantly greater …
Biotic Responses On Typha-Monodominant Semipermanent Wetlands To Cattle Grazing, Bryan David Schultz
Biotic Responses On Typha-Monodominant Semipermanent Wetlands To Cattle Grazing, Bryan David Schultz
Electronic Theses and Dissertations
Changes in the vegetative composition of most palustrine emergent semi-permanent wetlands is primarily a function of water level fluctuation. However, some wetlands do not exhibit vegetational shifts since emergent species such as Typha persist under flooded as well as drought conditions. Numerous techniques to control cattails such as burning and herbicide application have been suggested. The objective of this study was to test the use of cattle grazing as a method of controlling dense cattail stands in semi-permanent wetlands to improve breeding duck habitat. Plots (.81 ha) were established in the emergent zone in each of two wetlands (≤ 4 …