Southwestern Michigan Research Articles

The Yankee West: Community Life on the Michigan Frontier

Susan Gray explores community formation among New England migrants to the Upper Midwest in the generation before the Civil War. Focusing on Kalamazoo County in southwestern Michigan, she examines how 'Yankees' moving west reconstructed familiar communal institutions on the frontier while confronting forces of profound socioeconomic change, particularly the rise of the market economy and the commercialization of agriculture. Gray argues that Yankee culture was a type of ethnic identity that was transplanted to the Midwest and reshaped there into a new regional identity. In chapters on settlement patterns, economic exchange, the family, religion, and politics, Gray traces the culture that the migrants established through their institutions as a defense against the uncertainty of the frontier. She demonstrates that although settlers sought rapid economic development, they remained wary of the threat that the resulting spirit of competition posed to their communal ideals. As isolated settlements developed into flourishing communities linked to eastern markets, however, Yankee culture was transformed. What was once a communal culture became a class culture, appropriated by a newly formed rural bourgeoisie to explain their success as the triumphant emergence of the Midwest and to identify their region as true America. |Using Charlotte, North Carolina, as a case study of the dynamics of racial change in the 'moderate' South, Davison Douglas analyzes the desegregation of the city's public schools from the Supreme Court's 1954 Brown v. Board of Education decision through the early 1970s, when the city embarked upon the most ambitious school busing plan in the nation.

Ground‐Water Quality and Flow in a Shallow Glaciofluvial Aquifer Impacted by Agricultural Contamination

AbstractThe Prairie Ronde fan, a discrete glaciofluvial deposit in southwestern Michigan, contains a productive but highly vulnerable unconfined aquifer used for irrigation, municipal, and domestic supply. A comprehensive hydrogeological study of the aquifer delineated shallow, local flow systems that interact with ponds and wetlands on the fan surface, overlying a deeper intermediate/regional flow system extending to the base of the glacial drift. Ground water within the shallow flow systems contains tritium concentrations indicative of a post‐bomb age and is heavily impacted by nonpoint source contamination. Nitrate commonly exceeds drinking water standards in the shallow flow system. Although no continuous physical barrier separates the two flow systems, the deeper flow system is generally lacking in tritium as well as nonpoint source contaminants derived from surface land uses. High capacity pumping from the deeper flow system, however, will likely draw contaminants downward from the shallow flow system.Background‐water quality in the aquifer is controlled by equilibrium with calcite and slight undersaturation with respect to dolomite. No spatial trends in major ions were observed, suggesting that carbonate mineral equilibrium is achieved rapidly in the vadose zone and further chemical evolution along ground‐water flow paths is minimal. Iron concentrations are highly variable in the aquifer and not correlated with depth. Recharge from lakes and wetlands is a significant cause of elevated iron concentrations in the shallow flow systems.

Spectrogram contour features for intraspecific classification of narrow‐band animal sounds.

Recent research has indicated that contour features obtained from computer imaging are useful for characterizing some interspecific differences in narrow‐band animal sounds [B. Pinkowski, J. Acoust. Soc. Am. 95, 3419–3423 (1994)]. Contour features may also characterize the intraspecific differences of animal sounds that vary among individuals. To examine this possibility, six songs from each of ten eastern bluebirds (Sialia sialis) (5 males and 5 females) recorded during 1991 and 1992 in southwestern Michigan were digitized at 22 kHz, converted to spectrogram images, and analyzed for contour using Fourier descriptors (FD’s). Following smoothing, thresholding, and segmentation, the spectrogram components corresponding to three or more basic notes were merged by a simple pixel aggregation algorithm to yield a single contour per song. The contour border was then used to compute a 512‐point DFT. With 16 low‐order FD’s per song, 58 of the 60 songs (96.7%) were correctly classified by a linear discriminant function. Male songs were more varied and complex and hence more difficult to classify by contour alone than were female songs. [Work supported by NIH.]

Population Dynamics of the Colorado Potato Beetle (Coleoptera: Chrysomelidae) on Horsenettle in Michigan

Field studies during 1986–1988 in southwestern Michigan showed that horse-nettle, Solanum carolinense L., could be an important reservoir of Colorado potato beetle, Leptinotarsa decemlineata (Say), populations when potatoes, Solanum tuberosum L., are not planted. Early in the season, Colorado potato beetle laid most of its eggs on nonhost plants. Accumulated total larval mortality ranged between 82 and 99%. Predators with chewing mouth parts caused higher egg mortality at the beginning of the season whereas predators with piercing-sucking mouth parts preyed upon more egg masses by the middle of the season. Populations of Coleomegilla maculata De Geer were correlated with beetle 1st-instar densities and Perillus bioculatus F. was one of the most numerous predators of Colorado potato beetle. Given a choice of 7 potential host plant species, only horsenettle and potato were colonized by a Colorado potato beetle population adapted to horsenettle. Potato was a better host than horsenettle for this population, which has been isolated from potatoes for ≈40 yr.

Late Glacial Climate Record of Midwestern United States from the Hydrogen Isotope Ratio of Lake Organic Matter

A hydrogen isotope time series obtained from an analysis of organic matter extracted from a lake core in Kalamazoo, southwestern Michigan, reveals four distinct isotope stages within the last 12,000 years that can be interpreted in terms of oscillations between cold and warm, dry climates. The most dramatic are a cold phase between 12,000 and 9000 years before present (B.P.), a warm, dry period between 8500 and 2000 years B.P., a cold period between 2000 and 1000 years B.P., and a warming trend since 1000 years B.P. The warming trend of the last 1000 years is comparable in magnitude to the mid-Holocene warm phase.

Spatial Variation in Nitrogen Availability in Three Successional Plant Communities

1 Spatial variability in soil nitrogen and moisture levels was determined using a geostatistical analysis in a newly abandoned field, a mid-late successional field and a second-growth forest in south-western Michigan. 2 A greater proportion of the total variation for all variates associated with nitrogen availability was spatially dependent in the mid-successional field; the newly abandoned field and forest had similar patterns of spatial dependence in these variates. 3 The distance (range) over which there was spatial dependence was greater in the mid-successional field than the other two communities, indicating a more coarsegrained pattern of spatial heterogeneity in soil nitrogen, particularly in the surface soils (0-5 cm), than in the other two sites. 4 Examination of patterns of spatial dependence using different lag intervals generally gave similar results; though a nested pattern of N03-N availability in the midsuccessional field was detected at a finer scale of analysis, indicating spatial variation at multiple scales. 5 The results suggest that patterns of spatial variation in soil nitrogen change over time in successional plant communities, perhaps reflecting changes in the species composition or size of individual plants in these communities.

African American School Attendance in the 19th Century: Education in a Rural Northern Community, 1850-1880

INTRODUCTION Studies of African American education in the 19th century have focused primarily on developments after the Civil War, concentrating on the creation of segregated schools in the South (Bond, 1934; Frazier, 1949; Woodson, 1968, 1918/1969; Woodson & Wesley, 1922/1966). Prior to the antebellum era, documentation was sketchy and few schools existed in either the North or the South. The education of northern Blacks was decidedly different from that of southern Blacks. Much of what is known of African American education in the South during this period is based upon events that transpired in rural areas, primarily on southern plantations, where arrangements were most often made clandestinely and on pain of prosecution. The education of enslaved Blacks was forbidden by law in many southern states. In the North, if schools for African Americans did exist, they were generally housed in crowded, inferior buildings staffed by less-than-qualified teachers of either race, and restricted in their curricula offerings. Being freedmen and freedwomen rather than slaves, the educational demands of northern African Americans were for public education that would include them in common school reform efforts despite their small numbers and colored skin (Woodson & Wesley, 1922/1966, p. 256). They also banded together to make private arrangements for schooling and hired their own teachers. Frazier (1949) contends that northern Blacks in the antebellum period tended to locate in urban areas where skilled labor was sought; however, not all settled in urban areas. Despite the rapid industrialization that occurred during the 19th century and the increasing urbanization of the North, much of that region consisted of small, rural communities. Among these were communities in which African Americans settled and lived together with White Americans with no indication of racial intolerance. One such rural northern community was Calvin Township, located in Cass County in southwestern Michigan. Many of Calvin Township's African American citizens arrived a decade or more before the Civil War. Located at the junction of the Underground Railroad's(1) Quaker Line out of Kentucky and its Illinois Line to Canada, this community became a haven for African American fugitives from slavery in the mid-19th century (Dancy, 1940). Given this rural northern setting and a substantial population of African Americans, the present study sought answers to the following questions: What provisions were made for the schooling of the African Americans who settled in Calvin Township? Did they attend separate schools? Who among them attended school? Were there differences in the school attendance patterns between the township's Black and White children? What personal and family factors contributed to the former's school attendance? How did these change over time? This study addresses these questions by analyzing federal Census records, annual school district reports, and area maps to describe the school attendance of African Americans in Calvin Township in the 30 years from 1850 through 1880, before and after the Civil War. The findings of the study are presented in terms of characterizing the schooling experience of African Americans in a rural northern setting in the 19th century. CASS COUNTY Calvin Township in Cass County, Michigan, is an excellent focus for such an investigation for several reasons. First, during the years in question it was a rural northern farming community with a sizeable African American population established before the Civil War (Cass County Historical Commission, 1981; Claspy, 1967; Rogers, 1875; Schoelzow, 1935). By 1850, African Americans made up 3.6% of the population of Cass County, a percentage that, in the territory of Michigan, was surpassed only by Wayne County, which included the city of Detroit. Together with nearby Porter Township, Calvin Township accounted for two-thirds of the entire African American population in the county before the Civil War (Glover, 1906). …

Cost effectiveness of 24-hour ambulatory blood pressure monitoring in evaluation and treatment of essential hypertension.

We wanted to determine if use of ambulatory blood pressure monitoring (ABPM) was cost effective, preventing unnecessary drug therapy in patients misdiagnosed as having essential hypertension, with elevated office blood pressures and normal ambulatory blood pressure. To address this issue we surveyed costs to the patient for antihypertensive drug therapy in 1990 of five local pharmacies in southeastern Michigan. Patients studied (n = 192) were seen in a private, general internal medicine practice in rural southeastern Michigan and received ABPM to assess the presence of hypertension and the adequacy of blood pressure treatment. We ascertained the average, minimal, and maximal drug cost to the patient per unit dose at the local pharmacies. The average yearly cost for patients on antihypertensive medications at pharmacies in southwestern Michigan was $578.40, with figures varying from $94.90 to $4361.75. Although there is no standard reimbursement amount for ABPM, at $188 per monitoring, the cost of monitoring this entire group of patients would offset exactly the cost of medication for the group of patients found to have only office hypertension. As such, third-party insurance carriers should consider reimbursement for ABPM in hypertension to decrease pharmaceutical cost and its attendant potential side effects. In conclusion, our study results suggest that ABPM is cost effective in an outpatient setting in preventing unwarranted drug therapy and the inappropriate diagnosis of hypertension.

The disjunct coastal plain flora in the Great Lakes region

Three areas in the Great Lakes region are known to harbor species whose primary range is the coastal plain: (1) the southeastern Georgian Bay region of Ontario, (2) the sandplains near Lake Michigan in southwestern Michigan and northern Indiana, and (3) the lacustrine sand deposits in central and northern Wisconsin. Secondary areas with smaller concentrations are found in the southeastern Lake Ontario region of New York, the Lake Erie region, small areas of north-central Illinois, and local areas of northern Michigan. These areas are all sand deposits associated with postglacial lakes and drainage channels. A review of the flora of the Great Lakes region disclosed a list of 62 primarily coastal plain species that are disjunct to the Great Lakes region. The species are largely herbs, nearly half are graminoids, and many are annuals. Their habitats are primarily sandy, gravelly, or peaty emergent shores of shallow, soft-water ponds and small lakes with fluctuating water levels, or sometimes sandy, periodically flooded swales. A few species are aquatic, and fewer still are bog or wet forest species. Most are evident only during years of low water levels, and sometimes their appearance is quite sporadic, making survey and monitoring work difficult. However, the consequences of loss of populations can be severe since, with disjuncts, there may be no seed source nearby to facilitate recolonization of sites. The sandy lakeshore habitats are frequently prime recreational lands, thus creating additional pressures. Previous hypotheses for the occurrence of these disjuncts suggested gradual migration along the shores of postglacial lakes and drainages. However, these species do not typically inhabit shores of rivers and large lakes. As well, habitats along these shores undoubtedly were not continuous. Nevertheless, the localized occurrence of the species at the termini of major postglacial drainages in spite of the more widespread availability of apparently suitable habitats argues against random long distance dispersal. Here proposed is that these species migrated into the Great Lakes region through dispersal jumps of varying distances between substantial areas of suitable habitat created along major postglacial drainage channels. Once in the Great Lakes area, they were most successful in areas with extensive drying shorelines.

Nutrient additions by waterfowl to lakes and reservoirs: predicting their effects on productivity and water quality

Lakes and reservoirs provide water for human needs and habitat for aquatic birds. Managers of such waters may ask whether nutrients added by waterfowl degrade water quality. For lakes and reservoirs where primary productivity is limited by phosphorus (P), we developed a procedure that integrates annual P loads from waterfowl and other external sources, applies a nutrient load-response model, and determines whether waterfowl that used the lake or reservoir degraded water quality. Annual P loading by waterfowl can be derived from a figure in this report, using the days per year that each kind spent on any lake or reservoir. In our example, over 6500 Canada geese (Branta canadensis) and 4200 ducks (mostly mallards, Anas platyrhynchos) added 4462 kg of carbon (C), 280 kg of nitrogen (N), and 88 kg of P y−1 to Wintergreen Lake in southwestern Michigan, mostly during their migration. These amounts were 69% of all C, 27% of all N, and 70% of all P that entered the lake from external sources. Loads from all external sources totaled 840 mg P m−2 y−1. Application of a nutrient load-response model to this concentration, the hydraulic load (0.25 m y−1), and the water residence time (9.7 y) of Wintergreen Lake yielded an average annual concentration of total P in the lake of 818 mg m−3 that classified the lake as hypertrophic. This trophic classification agreed with independent measures of primary productivity, chlorophyll-a, total P, total N, and Secchi disk transparency made in Wintergreen Lake. Our procedure showed that waterfowl caused low water quality in Wintergreen Lake.

Temporal Variation in Growth Rate and Age at Maturity of Male Painted Turtles, Chrysemys picta

-Growth rates of juveniles and age at maturity of males were examined in a population of painted turtles, Chrysemys picta, inhabiting a marsh in southwestern Michigan (approximately 42024'N, 85024'W) to compare temporal variation in these two important life history traits within a decade. Elongation of the third right foreclaw was used as an indicator of incipient sexual maturity of males. Males in the late 1980s reached maturity at least a year earlier than did those in the early 1980s. Analysis of climatological data revealed that growing seasons in the late 1980s were typically warmer and longer than in the early years of the decade. The observed changes in juvenile growth rates and age at maturity of male C. picta are in accord with recent field and laboratory studies of emydid turtles. They also support predictions of life history theory, and may serve as working hypotheses that can be tested with data from other long-term projects. If substantiated, these patterns may indicate how some freshwater turtle populations in temperate latitudes might respond to predicted global warming trends.

Prune Brown Line Disease Occurrence in Declining `Stanley' Plum orchards in Michigan and Factors Related to Its Incidence

Twenty-one declining `Stanley' prune (Prunus domestica L.) commercial orchards in the southwestern, west-central, and northwestern regions of Michigan's lower peninsula were surveyed for prune brown line disease, associated with tomato ringspot virus (TmRSV). Fifty trees from each orchard were examined for a brown line and pitting-grooving symptoms beneath the bark at the graft union. Inner bark and cambium were taken at the graft union for ELISA testing for TmRSV. Dagger nematodes (Xiphinema americanum Cobb 1913) (the vector) were extracted from soil samples and enumerated. Dandelions (a TmRSV weed host) also were tested for TmRSV. Information on orchard cultural practices and orchard histories was compiled. The percentage of trees ELISA-positive for TmRSV ranged from 4% to 82%, with a mean of 27.9%. The percentage of orchards in the northwestern, west-central, and southwestern regions in which TmRSV was detected by ELISA was l8.0%, 32.3%, and 35.1%, respectively. There was a strong positive correlation between the percentage of trees with a brown line at the graft union and the percentage of trees in which TmRSV was detected at each location. The brown line symptom is a good indicator for the presence of TmRSV, but graft-union pitting and grooving did not correlate strongly with the presence of the virus. TmRSV was detected in dandelion plants in 63% of the orchards tested. Dandelion densities, which ranged from <0.5 to 10/m2, did not correlate positively with percentage of ELISA-positive trees. Numbers of dagger nematodes ranged from 0 to 132 per cm3 of soil. Vector nematode populations correlated positively with ELISA-positive trees from southwestern Michigan, but not in the other two regions. Orchard age, which ranged from 6 to 22 years, did not seem to relate to the percentage of trees in which TmRSV was detected, nor did the source of the plant material used to establish the orchards. Both `Myrobalan' and peach rootstocks were heavily infected. Preplant and at-planting applications of fenamiphos as a strip treatment were ineffective in preventing infection. We believe that TmRSV is endemic in Michigan orchard soils and that the virus is not being introduced to new orchards through the use of infected planting material.

Mapping Some Loamy Alfisols in Southwestern Michigan Using Ground-Penetrating Radar

Mapping Some Loamy Alfisols in Southwestern Michigan Using Ground-Penetrating Radar

Moral Champions and Public Pathfinders: Antebellum Quaker Women in Eastcentral Indiana

Moral Champions and Public Pathfinders: Antebellum Quaker Women in Eastcentral Indiana Peggy Brase Seigel* For twenty years before the outbreak of the Civil War, women from Quaker communities in Eastcentral Indiana championed social and political reforms, much like reform-minded women throughout northern states. In the 1840s women primarily concentrated in Wayne, Henry, Union, and Randolph counties joined the widening crusade against slavery. Organizing and participating in a broad range of antislavery organizations, these Indiana women were often as outspoken as their better-known sisters. During the 1850s women from the same areas led a state women's rights organization that brought women together each year to discuss women's inferior status and to arouse women to action. Their pre-Civil War efforts culminated in January 1859 when three of their leaders became the first women to present a women's rights petition to the Indiana General Assembly. Despite their attempts to change public opinion, to improve the condition of Black Americans, and to forge new directions for women of their day, however, these pioneer reformers have received little attention from historians. The connections between Eastern antislavery and women's rights reformers have long been established. Feminist historians including Blanche Glassman Hersh, Lori D. Ginzburg, and Nancy A. Hewitt explain this progression as a two-part process. In the 1830s Eastern women first became involved in public reform activities as a result of a growing religious fervor and newly realized leisure that encouraged women to work against the social evils of their day—slavery, intemperance , prostitution. Secondly, experiences as female reformers during the next decade inevitably led women into role conflicts with men and made women conscious of their own enslavement because of their sex. Many of these same women, in turn, sought to improve women's condition by organizing women's rights organizations in the 1850s and increasingly called for the power to vote (Hersh 7, 30, 3334 ; Ginzburg; Hewitt 27-28). Such patterns of feminist evolution, if applied to Indiana's antebellum women reformers, can be useful as preliminary schemes, but do not take into account either Indiana's isolation from Eastern reformers or Eastcentral Indiana's strong Quaker agrarian subculture. 88Quaker History Antislavery Reform in Indiana Although female antislavery societies were primarily concentrated in the East in the 1830s, organized antislavery work also began in isolated areas in Ohio and Michigan settled by evangelical protestants. Soon after the formation of the American Anti-Slavery Society and female antislavery societies in Philadelphia and Boston in 1833, women in Leanawee County in Southwestern Michigan organized an antislavery society under the leadership of two young Quaker women, Elizabeth Chandler, a native of Philadelphia, and Laura Haviland, a pioneer settler from Western New York. From her frontier home, Elizabeth Chandler wrote for two national antislavery newspapers, Benjamin Lundy's Genius of Universal Liberty and William Lloyd Garrison's Liberator, and thus became a link between national reform movements and the Michigan frontier. In 1835 Betsey Mix Cowles, a school teacher and daughter of a Connecticut-born Congregational minister, organized the Ashtabula County Female Anti-Slavery Society in the Ohio Western Reserve. Aside from reform newspapers that reached the state, however, Indiana remained bypassed by the influences of Eastern antislavery reformers until the end of the 183Os. Evangelical preachers of the Great Revival led by Charles Finney in Western New York as well as agents of the American Anti-Slavery Society trained by Theodore Weld to conquer the West are not on record as having come into the state. Only towards the end of the 1830s did formal antislavery organizations come into being with the formation of small local societies at Hanover College and in Dearborn County and the Indiana Anti-Slavery Society in Milton, Wayne County, in September 1838. The following year brought Arnold Buffum, a Quaker from Providence, Rhode Island, a leading lecturer for the American Anti-Slavery Society and thus the first reformer of national stature to reach the state. Simultaneously, men and women in Jefferson County organized the Neel's Creek AntiSlavery Society. In early 1841, eight years after the organization of the American Anti-Slavery Society, activities of Indiana antislavery societies became public record with the establishment...

Habitat Selection of Juvenile Blanding's Turtles, Emydoidea blandingii

Studies of Blanding's turtle, Emydoidea blandingii, in Massachusetts (Graham and Doyle, 1977), southwestern Michigan (Gibbons, 1968), southeastern Michigan (Congdon et al., 1983; Congdon and van Loben Sels, 1991), northeastern Missouri (Kofron and Schreiber, 1985), and central Wisconsin (Ross, 1989) indicate an apparent absence of juveniles. This may be a result of: (1) a real scarcity of juveniles due to high nest failure (Congdon et al., 1983); (2) juveniles occupying habitats not searched by the investigators (Gibbons, 1968; Graham and Doyle, 1977; Congdon et al., 1983; Kofron and Schreiber, 1985; Ross, 1989); or (3) higher mortality of juveniles versus adult turtles generally (Frazer et al., 1990). Whatever the cause, information concerning the ecology of juvenile Emydoidea is virtually nonexistent in the literature. The purpose of this study was to determine whether a relationship exists between body size of juveniles and habitat type. Juvenile Emydoidea (n = 95) were captured from 1974-1978 in the Weaver Dunes area of Wabasha

Growth, Survivorship and Longevity of Painted Turtles Chrysemys picta in a Southwestern Michigan Marsh

-This paper reports results of a mark-recapture study of painted turtles inhabiting a marsh in Kalamazoo County, Michigan, first begun in 1964-1966 and continued intermittently from 1980-1989. The relationship between plastron length (PL) and age (t) was described by von Bertalanffy growth equations for males PL = 111.8(1 0.792e-0?184t) and females PL = 152.2(1 0.852e-01281). Annual survivorship of males and females (26 yr old) was estimated as 0.64-0.83 and 0.29-0.50, respectively. Annual survivorship of juveniles (<6 yr old) was 0.21-0.51. Based on estimated minimum ages of individuals first captured as adults in the 1960s and recaptured in the 1980s, the four oldest males were 31 and the oldest female was 34 yr old. The oldest known-age male and female were 21 yr and 15 yr old, respectively. A comparison of data from the 1960s with that gathered in the 1980s revealed that the growth rates of juveniles and the density of turtles in the marsh have increased, while survival rates have apparently decreased. We speculate that the enhanced growth rates and population density are the result of warmer and drier weather during the 1980s.

Hemisphericity and Reading Achievement for Black and Caucasian Elementary Students

This study was done to assess whether black and Caucasian students differ in hemispheric skills and whether such preference is related to reading achievement. Subjects were 111 fourth- and fifth-graders from a small rural school district in southwestern Michigan. For this group there was no significant difference in inferred hemisphericity on the Cognitive Laterality Battery with respect to race or sex, neither was hemisphericity related to reading achievement on the Iowa Tests of Basic Skills. However, individual subtests of the Cognitive Laterality Battery were significantly related to reading comprehension on the Iowa achievement tests.

A Comparison of Methods for Estimating Seed Numbers in the Soil

(1) Seed-bank species composition and seed density were determined in an annually ploughed field at the Kellogg Biological Station in south-western Michigan, U.S.A. using three different methods: direct germination, germination following cold-stratification, and washing using a modified elutriation system. A fourth method, flotation on a salt-density gradient was abandoned after preliminary trials showed it was inefficient and inaccurate. (2) Twenty soil cores (2 5 cm in diameter, 15 cm deep) were taken from each of twentyfive sampling points in the field. Cores were divided into three depth intervals (0-2 cm, 2-5 cm and 5-15 cm) and five cores from each quarter of a sampling quadrat were combined and randomly assigned to one of the four methods for estimating the seed bank. (3) A total of fifty species was detected in the seed bank of this community. Overall, more species were detected with cold-stratification (forty-two species) than with direct germination (thirty-seven) or elutriation (thirty-five). Plots of species-sampling-area curves showed that fifteen to twenty sampling locations were sufficient to determine the number of species present in the seed bank with any of these methods. (4) Seed-density estimates were significantly higher in the elutriated samples. This was due primarily to the inclusion of inviable seeds in the counts from the elutriated samples. (5) There were significant differences in seed viability among species recovered in the elutriated samples. Both Ambrosia artemisiifolia and Chenopodium album, seeds of which were common in the samples, had low viability (25% and 3%, respectively). (6) Germination methods (particularly when more than one pre-treatment method is used) provide a more complete listing of species present in the soil seed bank of a community than elutriation. However, elutriation methods may be more useful for documenting variation in seed distributions on a large spatial scale or in quantifying the distribution of species with unique, easily identifiable seeds. Elutriation seems particularly well-suited for quantifying the distribution of plants that are considered weeds in agricultural systems, because many of these species have seeds that are easily identified and retain viability when dried.

Resource Limitation in a Stream Community: Phosphorus Enrichment Effects on Periphyton and Grazers

A field experiment was used to test whether stream periphyton was nutrient limited, and if so, whether the grazing insects that consumed this resource were food limited. Eight replicate wooden flumes were placed in an unshaded riffle in Augusta Creek, a third—order, hardwater trout stream in southwestern Michigan (USA). Phosphorus, in the form of Ca(H2PO4)2, was added to four of these flumes for 105 d. The average concentration of soluble reactive phosphorus (SRP) maintained in P—enriched flumes (85 mg/L) was &gt;5 times as great as in control flumes (15 mg/L). After 77 d of nutrient enrichment, periphyton biomass per unit area on substrates with reduced grazer densities was 1.8 x as great in P—enriched flumes as in control flumes. The larvae of two species of grazing caddisflies (Leucotrichia pictipes and Psychomyia flavida) in P—enriched flumes also had higher individuals mass, developmental rates, and population densities. These responses resulted in standing crops of final—instar larvae in P—enriched flumes that were 2.1x and 1.5x as great as those in control flumes for Psychomyia and Leucotrichia, respectively. This demonstration of food limitation supplements previous behavioral studies showing that both grazer species aggressively defend feeding territories, and contributes to a growing body of evidence suggesting that resource limitation is more important in some stream food webs than previously recognized. Resource limitation of these grazer populations may be due in part to the rarity of catastrophic flooding and drying in Augusta Creek. Such stable flows could permit consumer populations to reach higher densities than in frequently disturbed streams.

LOAMY SUBSTRATA AND FOREST PRODUCTIVITY OF SANDY GLACIAL DRIFT SOILS IN MICHIGAN

The study was conducted to ascertain the effect on forest productivity of underlying finer textured materials in sandy soils formed in glacial drift. A study area in south-western Michigan was used to examine the relationship. Ground-penetrating radar was used to measure the depth to finer textured layers in the sandy soils on 25 study plots. White oak (Quercus alba L.) trees were measured for site index (height in meters at 50 yr) on those plots. Regression analysis revealed a negative correlation (r2 = 0.45) between site index and the depth to finer textured layers in these sandy soils. Dividing the plots into three groups based on depth to finer substrata (&lt; 1.5 m, 1.5–2.9 m, and ≥ 3 m) revealed a significant difference among the groups. However, mean separation showed that only the &lt; 1.5 m group differed significantly from the other two groups at the 0.05 level. While the depth to finer textured substrata does influence tree growth on these sandy soils, the influence appears to begin to wane at depths &gt; 1.5 m. Key words: Forest productivity, ground-penetrating radar, sandy glacial drift, loamy substrata