Margaret R. Gale

Evaluation of national wetland inventory maps in a heavily forested region in the Upper Great Lakes.

National Wetland Inventory (NWI) maps are widely used in the United States but have not been independently evaluated in the Great Lakes region nor in forested areas with level topography. Field data from 148 plots in the Hiawatha National Forest ecological classification and inventory program were combined with an additional review to evaluate NWI mapping accuracy. NWI maps were over 90% accurate in identifying uplands and jurisdictional wetlands. All nonforested wetlands were identified correctly. Uplands were correctly identified 96.9% of the time. The lowest level of accuracy, 90.7%, was achieved in identifying forested wetlands. The most common error was the NWI classification of wetlands on the AuGres soil series, a somewhat poorly drained upland soil that often occurs in complexes with wetland soils in the region. Forested wetlands with a cover type similar to adjacent uplands were also a source of error on NWI maps. The already high accuracy of NWI maps could be improved by the mapping of wetland-upland complexes, a development corresponding to the increased mapping of hydric-nonhydric soil complexes in area soil surveys. The continued refinement of regional lists of hydrophytic vegetation is supported by indicator status discrepancies between an extensive Hiawatha National Forest database and the current NWI list for the region.

Prehistoric, historic, and present settlement patterns related to ecological hierarchy in the Eastern Upper Peninsula of Michigan, U.S.A.

The distribution of human occupation across a landscape provides informationabout how people use the landscape, about patterns of economic development,and about social interactions of human groups. When the distributions areexamined over several thousand years, we gain an evolutionary understanding,not only of the people and their cultural patterns, but also of physicallandscape development. The focus of this assessment was to examine andcompare settlement patterns of prehistoric, historic, and present timeperiods, based on known cultural sites in the Eastern Upper Peninsula ofMichigan, U.S.A., and to generate hypotheses about the interaction ofsettlement pattern and landscape change at multiple scales. Patterns ofsettlement among the three time periods were compared at three geographicscales: by subregional ecosystems, by landscape ecosystems and by terraincharacteristics. The Michigan Bureau of History database of archaeologicalsites was searched for prehistoric habitation sites of Middle or LateWoodland period (ca. 3000-300 years before present). Historic occupationswere drawn from pre-European settlement landscape data based on General LandOffice survey notes of the 1850s. We extracted “urban” categories from landcover classified from Landsat Thematic Mapper imagery to measure presentoccupations. Spatial patterns and dynamics of settlement areas in each timeperiod were examined using the ARC/INFO geographic information system (GIS).Results showed a tendency for settlement in all time periods on the bedrockand lowland landscape groups near Great Lakes shorelines, generally occupyingslopes less than two percent. The distribution of present occupations, interms of both slope aspect and geographic subregion (multi-scalar), wassimilar to the distribution of prehistoric occupations. Both prehistoric andpresent sites were primarily south facing and were frequently found alongGreen Bay and Lake Michigan shorelines.

A process-based growth model for young red pine

Abstract A carbon-balance, process-based growth model was developed to simulate the growth of young red pine ( Pinus resinosa Ait.). The dry weights of current, 1-year-old, 3-year-old needless, stems and branches, and roots of individual trees were considered as state variables. The hourly rate of photosynthesis was calculated with solar radiation, air temperature, leaf water potential, and leaf age as driving variables by assuming that the needles experience the same incident light density. Maintenance respiration rate was assumed to be a function of surrounding temperature. The seasonal allocation of assimilates to each compartment was determined by the activity of each compartment and was regulated by soilwater potential. The translocation of carbohydrate reserves, litter fall, and root turnover were incorporated in the model. The simulated results fit well with observed values from three plantations in the central Upper Peninsula of Michigan.

Soil factors related to dissolved organic carbon concentrations in a Black Spruce Swamp, Michigan

Controls on dissolved organic carbon (DOC) concentrations were examined through field and laboratory measurements of a Typic Haplaquod in Michigan. Average DOC concentration in the soil solution at 30-cm depth was 32 mg/L, and groundwater DOC concentration at 2-m depth was 18 mg/L. Oxidation-reduction (redox) potentials measured in the upper 30 cm of soil ranged from −220 mV to +500 mV, indicating the presence of both reduced and oxidized conditions at the site. Mineral soil organic carbon (SOC) ranged from 0.47% in the Bg horizon to 2.70% in the Bhs horizon. Citrate-dithionite extractable iron (Fe c/d ) ranged from 5.9 μg/g in the E horizon to 85.0 μg/g in the Bhs horizon

Plant community responses to harvesting and post-harvest manipulations in aPicea-Larix-Pinus wetland with a mineral substrate

Forested wetlands in the Northern Great Lakes Region are becoming increasingly used as a timber resource. Yet, limited information is available on the effects of harvesting and post-harvest manipulations (site preparation and fertilization) on tree and ground vegetation in these wetland communities. The objective of this study was to examine production changes and species diversity in the vascular plant community four years after a forested, mineral wetland in Northern Michigan was whole-tree harvested, site prepared (bedded or trenched), and fertilized (N, P, N + P). The wetland had an original overstory of black spruce (Picea mariana), tamarack (Larix laricina), and jack pine (Pinus banksiana), with a significant cover ofSphagnum and Ericaceous shrubs. Site preparation techniques were done immediately after harvesting. The site was then planted with jack pine seedlings (1–0 stock). Fertilization occurred four years after harvesting and site preparation. Results indicate that trees in bedded areas with N fertilizer applied had significantly greater total seedling height, basal diameter, and height increment when compared with those from harvest-only or trenched areas. On harvest-only areas, seedling production was greater with P and N + P fertilizers than with N fertilizer alone. Fertilizer responses were attributed to which type of site preparation (bedding versus trenching) was used and the degree of organic matter andSphagnum incorporated into the mineral soil. Only site-preparation treatments (not fertilization treatments) had significant effects on numbers and cover of vascular plant groups (woody, herbaceous, and grass/sedge). Number of species and total cover of all vascular plants were significantly greater on the harvest-only areas than on trenched, bedded, or uncut areas. As expected, relative cover of the grass/sedge group increased with increasing site disturbance (bedded and trenched), mainly due to disturbance and lack of the thickSphagnum mat. When compared to the adjacent uncut area, relative cover of herbaceous species was significantly reduced on treated areas. In future years, if the significant effects of manipulation treatments on tree productivity and vascular plants continue, the resulting community may be different than the successional sequence witnessed by the original forest. This will, however, depend on the rate of crown closure and the invasion of bryophyte species.

Vascular and non-vascular plant community response to silvicultural practices and resultant microtopography creation in a forested wetland

Forested wetlands are important ecosystems valued for their indigenous plant communities, spatial heterogeneity, wildlife habitat, water quality, and timber resources. When harvested for timber, plant composition in these wetlands may change due to alteration in microsite habitats. Harvest severity also may affect plant composition. In this study, a mineral conifer wetland was subjected to whole-tree harvesting followed by installing different site preparations (bedding, trenching, draining). The original wetland overstory was Picea mariana, Larix laricina, and Pinus banksiana, with groundcover dominated by Sphagnum russowii. Eleven to twelve years after harvest, we assessed responses of vascular and non-vascular plants to created microtopographies (pits, side slopes, mounds) to determine whether harvest severity affected species richness, diversity, and relative cover of plant communities. For all the microtopography positions, the more severe harvest treatments (drained, cut, trenched) had the highest plant richness but the lowest diversity values. Richness and relative cover of Sphagnum species were highest in reference areas and much lower in the most severe harvest treatments (drained, cut, trenched). In contrast, graminoid and, to a lesser extent, herbaceous and woody plants increased in richness and cover after harvest.

Influence of Surface Water Mineral Nutrition on the Plasticity of Sarracenia purpurea in Sphagnum fens, Marl Wetlands, and Sand Savannahs

Sarracenia purpurea, the northern pitcher plant, inhabits three very different wetland habitats throughout its range: two acidic, low nutrient wetland types (Sphagnum and sand substrate-based) and one alkaline wetland type (marl substrate-based) located primarily within the Great Lakes region. This study attempted to classify the nutrient status of the rarer marl wetlands in relation to the acidic Sphagnum and sand substrate-based wetlands and to examine the morphology of S. purpurea growing in these wetland types. S. purpurea has previously shown morphological variation in response to nutrient availability but also in response to environmental changes unrelated to nutrient concentrations. We sampled water chemistry and plant morphological variation within the three distinct habitat types. Marl wetlands, regardless of significantly higher pH levels, were characterized by over all low nutrient concentrations with high levels of calcium (mg Ca/L) and sulfate (mg S/L). S. purpurea plants growing in high calcium concentrations showed reduced flower heights and leaf lengths. All sampled wetland types showed low overall nutrient concentrations, regardless of pH with S. purpurea plasticity partially influenced by wetland-specific water chemistry.

Paleoethnobotanical Inquiry of Early Euro-American and Ojibwa Gardens on Grand Island, Michigan

Exploratory archaeobotanical analysis was conducted on Grand Island, Michigan, in concert with current botanical inventories and historic document research. Our goal was to synthesize these three forms of data in the study of early cultural-plant use. We describe indigenous and Euro-American plant relationships on Grand Island, and the patterning of plant remains between individual sites. Botanical materials in four of five samples showed greater correspondence to current flora than to historic accounts of plant representation. Still, from most samples we recovered a good depiction of historic food plants. A well-defined feature sample yielded the greatest quantity and diversity of culturally important botanical material. The results support integration of documentary with archaeological sources to identify plant remains with cultural meaning.