2002 RESEARCH HIGHLIGHTS FROM FACTIVITIES

    The Coop Unit distributes a monthly newsletter titled Factivities. The newsletter begins by highlighting one research project that meets one research need listed by the Coop Unit’s supporting agencies. The highlighted project is usually a completed thesis, dissertation, publication or final report. Also in Factivities are preliminary research results, a list of publications, presentations and awards, notices and significant teaching and technical assistance efforts. 2002 highlights follow.

JANUARY

Research Need: Management methods for large rivers to conserve rare birds.

Research Finding: High flows in the Missouri River in 1997 piled up new sandbars, a whopping 4-5 times more habitat than was available in 1996. Natural hydrology produced more habitat than man ever could (the Corps tried to build some sandbars one summer)! The lightly vegetated habitat was optimal for tern and plover nesting and the new sandbars occurred in complexes rather than as single large bars.  Since 1998 vegetation has encroached and sand bar erosion has reduced available nesting habitat, but conditions are still better than in the early 1990s. Plover and tern productivity has improved as a result of the improved habitat. The research shows the potential value of flows in meeting the recovery need of these species, so say Coop Unit Research Assistant Bruce VanderLee and Principal Investigator/Assistant Unit Leader Dr. Kenneth F. Higgins.

FEBRUARY

Research Need: Biodiversity and management in Conservation Reserve Program (CRP) grasslands and Prairie Pothole Joint Venture (PPJV)-prescribed rotational grazing pastures.

Research Finding: After monitoring birds, insects and vegetation, Dr. Higgins and students developed species lists for these lands and concluded that CRP pastures under rotational or season-long grazing treatments maintained equal or higher mean male bird densities compared to idle CRP control fields. At moderate stocking rates (2.1 AUM/ha) grazing CRP lands could be included in contract terms or in negotiations in any extensions or modifications of future CRP contracts without any significant losses to nongame birds. PPJV grazing systems help conserve prairie by improving its economic viability without diminishing habitat for grassland passerines and in dry years may enhance breeding bird habitat compared to that on traditional grazing systems, especially for grazing sensitive species such as bobolink and Barid’s sparrow.

MARCH

Research Need: Isotope “fingerprints” of walleyes tell lake origin. 

Research Finding: Differences between reservoir walleyes are so distinct that stable isotopes may provide a useful diagnostic (e.g., law enforcement) tool for discerning walleye origin. This may be particularly useful under present management regulations, where the daily limit of walleyes in Lake Oahe is higher (N=10) than the daily limit in other Missouri River impoundments (N=4). Assistant Unit Leader Dr. Steven R. Chipps and graduate research assistant Blake Davis did a study of walleye trophic interactions that revealed interesting differences in stable carbon isotopes from walleyes in Missouri River impoundments. Walleye size was not correlated to ¹³C signatures, but ¹³C ratios measured from walleye tissue samples were significantly lower in Lake Oahe than in Lake Sharpe.  

APRIL

Research Need: Information on native grasslands that might be converted to cropland.

Research Finding: About one million acres of relict tallgrass prairie remain in about 17,000 tracts in eastern South Dakota and Dr. Higgins and the Gap Analysis Project folks have mapped them all. Ground truthing showed that aerial photo interpretation was 50% accurate for small tracts and 90% accurate for large tracts.  Floristic species richness (30 - 140) was the same on public and private lands. These data can be considered a baseline as the new Farm Bill is implemented. Under the new bill, more landowners may break native prairie to plant price supported commodity crops. 

MAY

Research Need: Increase productivity of rare least terns and piping plovers.

Research Finding: Egested raptor pellet collections, track and trial surveys, time-lapse photography and visual observations were used to identify predators at active tern and plover colony sites on sand bars downstream from Gavins Point Dam on the Missouri River. Predation was the leading cause of nest and chick loss. Crows, raccoons and mink caused 98% of the documented chick mortalities. Predator exclosures placed over plover nests increased nest success from 34 to 61%. “Predation rates and effectiveness increase as sandbar habitat decreases”, says Dr. Higgins. Graduate student Casey Kruse, now with the Corps of Engineers, did this study several years ago and the study was recently published in a peer-reviewed journal.

JUNE

Research Need: Information on floodplain aquatic habitats of regulated rivers.

Research Finding: Floodplain wetlands are important components of lotic ecosystems and can provide information about human impacts to large rivers. In the Upper Missouri River Basin impoundments have changed the natural flow regime, altering the distribution and condition of floodplain wetlands. As part of a recent REMAP study (with U. S. EPA), we developed biomonitoring criteria for floodplain wetlands in the upper Missouri River. An index of biotic integrity included six variables that were useful for distinguishing between reference and impaired sites. Metrics included one periphyton category (pollution intolerant), two vascular plant categories (number of obligate wetland species and the index of conservatism) and three macroinvertebrate categories (culicidae biomass, proportion of chironomids and diversity). Application of this multimetric IBI to randomly selected floodplain wetlands revealed an average IBI score of 65 (range 13-75), with a qualitative rating of “good”. This information will prove useful for future monitoring and evaluation of the ecological health of floodplain wetlands in the Upper Missouri River. Graduate students working on this project included Neil Haugerud, Kipp Powell and Kent Werlin, who are guided by Dr. Chipps and South Dakota State University (SDSU)’s Dr. Daniel E. Hubbard.

JULY

Research Need: Conservation and monitoring methods for tallgrass prairie.

Research Finding: We assessed the effects of land-use on characteristics (e.g. vegetation height, vegetation density, effective leaf height, litter depth) of tallgrass prairie in private and public ownership. Dr. Higgins and Dr. Gary Larson (SDSU Biology Department) suggest measuring these vegetation characteristics for monitoring. Their results also showed that vegetation structural qualities of tallgrass prairie remnants vary significantly among land-use treatments (e.g. grazing) and among stewardships. Higher wildlife values were found on public and well-managed reference sites and lower values for private sites, but there is room for improvement in land management on public and private land. Most public sites suffer from overabundance of litter and an abundance of Eurasian grasses (e.g. Kentucky bluegrass, smooth bromegrass, quack grass). On the other hand, private sites suffered from lack of litter and sparse vegetation because of intense grazing. Vegetation could be enhanced with systematically employed rotational grazing systems. Range management recommendations should be reviewed for tallgrass tracts. Dr. Larson was interviewed about tallgrass prairie recently by the Sioux Falls Argus Leader.

AUGUST

Research Need: Decision support for large scale and long term planning.

Research Finding: The four year South Dakota Gap Final Report is finished. This two inch thick monster is 91 pages of text and several hundred pages of appendices analyzing the gaps between where animals are located and lands under Status 1 or 2 protection. Status 1 and 2 are State and Federal land (National Parks, State Parks, National Wildlife Refuges) where major changes in land cover and natural resources are not allowed. Forest Service land is in Status 3 because of the many extractive uses, even though there is some conservation management in the National Forests. Less than 1% of South Dakota land is Status 1 and 2. To call a habitat type or species “safe” it should be protected on at least 10% of its range. Overall, 25 of 455 vertebrate species in South Dakota were protected in >10% of their ranges. Of the terrestrial vertebrates, only 6 of 358 species were protected, whereas 19 of the 97 aquatic vertebrates were protected. Of the bird species protected, all were associated with wetlands and were protected on national refuges and WPAs. What does one do with this information? The Lyon County (Iowa) Conservation Board bought 72 acres of farmland along the Little Rock River, which is proposed as Topeka shiner critical habitat. The County owns 13 preserves which “fill gaps in protection” of the Topeka shiner and other wildlife.

SEPTEMBER

Research Need: How does iron in Black Hills Reservoirs (Deerfield, Pactola, Sheridan, Stockade) affect reservoir productivity?

Research Finding: Reservoir nutrient availability can be reasonably predicted by models of external phosphorus loading rates (P). In Black Hills reservoirs, external P loading rates ranged from 0.8 mg P/m2/d in Deerfield to 7.5 mg P/m2/d in Stockade Reservoir. However, in Black Hills reservoirs, two important internal factors are 1) sediment iron concentrations that can reduce the availability of P to algae, and 2) low oxygen levels that cause P release from sediments. Unit student Ben Holcomb and Dr. Chipps concluded that standard P models were okay for predicting reservoir nutrient levels, but the “sediment phosphorus-to-iron-ratio” was a much better predictor of nutrients because it integrated both external (e.g. P loading) and internal (e.g. oxygen and Fe availability) factors affecting nutrient availability. Sheridan and Stockade reservoirs had summer anoxia resulting in increases (>150%) in total P from sediment release of P. The two extremes in reservoir conditions were:

OCTOBER

Research Need: Biodiversity in national parks to design prescribed fire program.

Research Finding: Wind Cave National Park has never had a small mammal survey done. For the purposes of this study, small mammals weigh less than ten pounds and do not fly. Trap lines (live and fatal traps) were run in twenty different vegetation “alliances” (alliance is the veg-speak for “community”). About 2000 mammals representing eighteen species were recorded. Most common were mice (deer and white-footed), followed by least chipmunk and southern redbacked vole. Rare species included hispid pocket mouse and least shrew. Riparian areas contained the highest species richness, followed by woodland and grassland in order. Radio collared female flying squirrels had a home range of about ten acres that usually included ponderosa pine/little bluestem vegetation alliance. The study was done by graduate student Jeremy Duckwitz under the supervision of Dr. Jonathan A. Jenks (SDSU, Wildlife and Fisheries Sciences). The Coop Unit helped with contracting (RWO 76); Dr. Higgins served on the graduate committee.

NOVEMBER

Research Need: Students in SDSU’s Advanced Limnology class (taught by Dr. Chipps) were very creative in using an ice-covered lake to test theories about aquatic animal behavior. The aquatic animals were water fleas (e.g. daphnia, bosmina); several could fit on a pin head, but close up, these little zooplankton have antennae that they use like oars for migrating and eyes that can evaluate light intensity. The water fleas migrate toward the surface at night and then sink into darker depths during the day; sometimes traveling thirty feet an hour (a lot of antennae action). Vertical migrations probably take place to get better food near the surface at night and avoid sight-feeding fishes during the day. While ice fishing on a 400-acre slough last winter, Dr. Chipps saw areas of snow-covered ice and areas of clean ice. His class hypothesized that if water fleas avoid light, then there would be more of them under snow-covered ice than under clear ice.

Research Finding: Light levels where ten times higher under clear ice (1.75 lux) than under snow-covered ice (0.175 lux). Under clear ice, water flea density was only one flea/liter, whereas under snow-covered ice density was higher (four fleas/liter). This class project is one of the few studies of under-ice behavior of water fleas and it was accepted for publication in a national journal – now that’s education!

DECEMBER

Research Need: Information on fish in South Dakota rivers.

Research Finding: The White River rises in the pine ridge country of northeastern

Nebraska and flows uninterrupted to Lake Francis Case. It is among the 15% of America’s rivers that (if preserved) would conserve ALL of the fish and mussel biodiversity in the U. S. We collected two mussel species (floater, fatmucket) in the upper basin during recent fisheries surveys, but no detailed invertebrate surveys have been done. Three of South Dakota’s seven turtle species (common snapping, spiny softshell, Western painted) might be in the basin, but were not collected in fish traps in the main channel. Coop Unit turtle student Sarah Bandas will take another look this coming summer. Six amphibians (e.g., northern leopard frog, bullfrog, great plains toad, chorus frog) occur in floodplain wetlands adjacent to the White River. The forty-nine species fish list includes forty-one natives and one exotic (common carp) and seven introduced species (brown trout, rainbow trout, brook trout, black and white crappie, largemouth bass, bluegill), which are rarely found except for common carp. Ubiquitous species found in both states, in the main river and in tributaries are: channel catfish, green sunfish, longnose dace, sand shiner and white sucker. Sturgeon chub, flathead chub and plains minnows have declined in other parts of the Missouri River Basin. There are no Federal endangered or rare species, but nine species are listed as state “species of concern”, mostly because of the number of glacial relicts and species on the edge of their range. Certain fish assemblages have specific geographic associations. The spring-fed stable flows in the upper basin support introduced trout and mountain sucker, a relict species. The lower main stem is used by large Missouri River species (e.g., paddlefish, flathead catfish). Tagged paddlefish return to the river each spring. The Little White River has glacial relict species and other natives that are adapted to clear, headwater streams (e.g., pearl dace, finescale dace, blacknose dace, blacknose shiner, northern redbelly dace, stoneroller). Channel catfish make up 22% of the catch in hoop nets and seines, but growth was slow compared to other river populations in the region, especially for < four-year-old fish. Reduced production is expected in this turbid, harsh environment.

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