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 Printer VersionEcosystem GuideGuide to Using the Classifications and Map of Landscape Ecosystem Types of UMBSGetting Started People using the classification and map of the local landscape ecosystem types are urged to read the Introduction to Landscape Ecosystems of UMBS (Part 1) in which we explain the ecosystem approach and describe the various products resulting from this research. These products include the two maps of UMBS landforms, the map of local landscape ecosystem types, the cover type map, and all the documentation that goes with each. People are also urged to read the Geologic History and Guide to the Classifications and Maps of the Landforms of UMBS so they have the physiographic basis for understanding the complex kinds and patterns of local ecosystem types found on UMBS land.Classifications of Ecosystem Types Presented below is a guide to the landscape ecosystem type classifications and map. There are two classifications of the landscape ecosystem types that are shown on the map.1. The first classification and brief description of the ecosystem types (Part 3, Item 1; 9 pages) is organized by the ecological and functional similarity of the ecosystems. Similar ecosystems are grouped together regardless of where they occur (on which landform) on the area. This classification lists ecosystems (types in hierarchical groups) that would support similar plant and animal species and respond similarly to experimental treatment. 2. The second classification (no description of types provided) lists the ecosystem types (Part 3, Item 2; 2 pages) by the landforms where they occur in the field, regardless of differences in their physiography, soil, vegetation, or functioning from other ecosystems occurring on that landform. This classification differs from #1 above in that all the kinds of local ecosystem types occurring in a particular landform are grouped together. For example, the large moraine landform located along the county line north and south of Robinson Road includes dry, nutrient poor ecosystem types similar to those on the high-level outwash plain as well as mesic and fertile ecosystems having less than 3 m of outwash over glacial till. Because this major morainal landform is a geographic feature in the landscape all its ecosystems are grouped together in this classification. Classification of Ecosystem Groups For many purposes, people will want to study and use groups of similar ecosystems rather than the local ecosystem types themselves. What are groups of ecosystems? Ecosystem groups are the collection of ecosystem types that have one or more similar properties (e.g., calcareous ecosystems of the Pellston Plain (types 11-19); shores and active beaches of Douglas and Burt lakes (types 86-89), etc.). Ecosystem types in a given group would be those listed under each hierarchy of the ecosystem type classification (classification # 1 described above). Thus for classification 1 there are as many ecosystem groups as there are hierarchical levels of the classification.The third classification of this part (titled: Landscape Ecosystem Groups of UMBS; Part 3, Item 3; 2 pages) identifies the hierarchy of ecosystem groups for ecosystem type classification #1 described above. Introduction To Using The Ecosystem Type Classification And Map Landscape ecosystems are volumetric pieces of the earth's surface that have characteristic and recognizable climate, physiography, soil, and biota. They can be conceived as existing in a nested hierarchy of spatial sizes, the largest being the earth, or ecosphere, and the smallest mapped at UMBS being local landscape ecosystem types such as a kettle-hole bog dominated by leatherleaf or a lakeshore terrace supporting red pine and low sweet blueberry. The ecosystem concept imparts major importance to their geographic, geologic, and climatic factors as well as the biotic components. Global geological and climatic patterns control the broad distribution of soil types and organisms, and local physiographic features (landforms; e.g., kames, moraines, and dunes) modify local climate (including temperature and wind) and drainage. Thus the local occurrence of soils and organisms (especially plants) corresponds with specific landforms and their attributes such as parent material, slope aspect, slope percent, and slope position. Areas that are relatively similar in these physiographic characteristics are found to have similar soil and biota. A given glacial landform is typically relatively homogeneous with respect to topography and parent material, and thus forms the basis for an ecosystem group, within which local ecosystem types are nested (Rowe and Sheard 1981, Host et al. 1987, 1988).The landscape ecosystem research team at UMBS has been engaged in the process of identifying, describing, classifying, and mapping the landscape ecosystems of UMBS since 1988. The classification and map of landscape ecosystem types presented here are the results of six field seasons of research, the first two carried out by Marc Lapin in 1988 and 1989, and the latter four by a team of researchers from 1991-1994. These products provide a framework for further research; the ecosystem map, in particular, is a set of hypotheses that can be tested at any of the hierarchical levels of the classification. The local physiography of the UMBS landscape modifies regional climate, and the microclimatic differences influence ecosystem development. For example, the broad, flat, plain on the western third of the property, known as the Pellston Plain, is climatically distinct from the rest of the property. Cold air drainage from the higher moraine to the west and the moraine-outwash complex to the east creates a broad frost-pocket, where diurnal temperatures can vary as much as 64 F (36 C) in summer (Barnes 1959). This climatic difference may account for differences in vegetation on areas with otherwise similar parent material and soil. The major landforms (Outwash Plain, Ice-contact Terrain, and Moraine) form the first level of the hierarchy of ecosystem groups and types. Within each landform, slope or soil parameters characterize subsequently lower levels. As typical of a glaciated landscape, however, the major landforms are quite complex, and ecosystems that are essentially the same with regard to physiography, soils, and vegetation may occur on different major landforms. This complexity is most evident on the large interlobate moraine; the glacial till of the moraine has been mostly covered by outwash. Where that outwash is greater than 3 m in depth, the influence of the till on moisture and nutrient availability is considered insignificant, and the ecosystems are considered to be of outwash origin, not morainal. Ecosystem types 59-64 comprise the outwash ecosystems that occur on moraine landforms. Methods Used In Distinguishing And Mapping Ecosystem Types Starting with an analysis of USGS 7.5 minute quadrangle maps and aerial photos (both black and white infra-red 1: 16,300 and color infra-red 1:24,000), major landforms and ecosystems were identified. Through reconnaissance and sampling of transects and formal plots, tentative ecosystem groups and types were identified. Lapin (1990), working alone for two field seasons, mapped and described UMBS landforms and ecosystem groups, providing a significant starting point for the research that followed. The preliminary ecosystem types were determined in 1991 and 1992 and field checked through an iterative process of reconnaissance, transect and plot sampling. By walking across potential landscape boundaries and recording changes in physiography, soil, and vegetation, the research team gained both familiarity with the ecosystems and practice in distinguishing their boundaries. Hypothesized ecosystem groups and types were further tested by sampling rectangular plots (15 x 30 m). Physiographic variables measured at each sample plot included slope position, aspect, and percent. Slope percent was measured along the aspect and along the north and south axes of the plot. Convexity/concavity was assessed, and distance to nearest surface water was determined from topographic maps. Landform (e.g., outwash plain) was determined through assessment of physiographic parameters.Thickness and pH of soil organic horizons were measured at three locations within the plot. A soil pit 1-2 m in depth was dug in a randomly determined location within the plot, and the observable horizons were described in terms of depth (range and average), pH, texture, color, structure, consistency, and percent pebbles and cobbles (United States Department of Agriculture 1975). One sample (1-2 pints) was collected for each mineral horizon described. In addition, an auger was used to briefly describe soil below the pit (to 4-5 m) and determine depth to water table. Vegetation was sampled in three strata: overstory, understory, and groundcover. DBH (diameter breast height; 1.4 m) and species of all overstory stems (DBH > 9 cm) within the plot was determined. Understory stems were identified to species and assigned to one of three DBH classes (1.5 - 4.0, 4.1 - 6.6, and 6.7 - 9.0 cm). The plot was divided into three 5 x 30 m subplots, and groundcover (DBH < 1.5 cm) was sampled in the center subplot only. All groundcover species present were noted and each assigned to one of 12 cover classes (Simpson et al. 1990). Coverage was determined by counting the number (or fraction) of sample frames covered by each species (one sample frame represents 0. 1% of subplot area). Ecological species groups were developed as in Spies and Barnes (1985b). Through reconnaissance and sampling researchers gained familiarity with groups of groundcover shrubs and herbs that co-occur in patterns related to abiotic factors. Initial groups that reflect ecological extremes were developed, and with additional observations and review, intermediate groups were identified and refined. See Part 4 on Ecological Species Groups. Mapping of local ecosystem types was accomplished through a field procedure similar to that detailed by Spooner (1984) and Hix (1983) and is described in Pearsall (1995). To locate ecosystem boundaries in the field and transfer them accurately to a 1: 16,300 enlargement of a USGS map, a 5-chain interval mapping grid, composed of main lines at 10-chain intervals and side lines, was completed. Each main line was begun from a predetermined starting point and at a known azimuth; horizontal distance was measured with a 2-chain (132 ft., 40.22 m) steel tape. From the starting point, a side line (wing) was paced out 5 chains at an azimuth 90' from the main line, then 5 chains at an azimuth parallel to the main line, then back towards the main line to intersect at 5 chains from the starting point. From that intersection, a wing on the opposite side of the main line was completed, and the process repeated until the end of the central line was reached. Ecosystem boundaries (as interpreted from changes in physiography, drainage, and/or coverage of ecological species groups), roads, trails, and other landmarks were recorded onto field mapping sheets when encountered. The ecosystem teams hiked over 750 km in mapping ecosystem types and determining their boundaries by multiple site and vegetative factors. Ecosystem boundaries were compiled from field mapping sheets onto mylar overlays and digitized from those into Arc/Info (ESR1 1992), a Geographic Information System (GIS). Enlargements of USGS 7.5' maps for the Indianville, Pellston, and Burt Lake quadrangles were used for the base maps of roads, section lines, shorelines, and streams. ARCPLOT (an Arc/Info module) was used to create four maps of landscape ecosystem types, one at the 1: 16,308 scale depicting UMBS land exclusive of Colonial Point, two maps covering the western and eastern parts of the same UMBS area at a 1: 10,000 scale, and one of the Colonial Point area at 1: 10,000. These larger scale maps show the boundaries of small ecosystem types better than the smaller scale map of the entire UMBS tract. The digital maps of ecosystem types, as well as those of major landforms, major and minor landforms, and the cover types, are available at the School of Natural Resources and Environment (contact Burton V. Barnes, 2532 Dana; 734/764-1407). They are also available in ArcView (another GIS) form by contacting Bob Vande Kopple at UMBS. Interpreting The Description Of Ecosystem Types A brief description of each landscape ecosystem type is given in Classification #1 (Part 3, Item 1). It consistently gives important attributes of each type. Typically, the sequence is the drainage class, a general soil characteristic, the characteristic physiographic position, and finally the vegetation (presettlement overstory type and characteristic ecological species group). The detailed descriptions of each ecosystem type appear in Appendix A: Descriptions of the Landscape Ecosystem Types of the University of Michigan Biological Station.Landscape Ecosystem Types As Hypotheses For Testing The landscape ecosystem types we have identified, classified, described, and mapped are our best approximation of the basic units of nature. We recognize that this version is not the final approximation; the classification (Part 3, Item 1) and map provide types that are hypotheses for testing. The ecosystem types are "carved out" of the continuum of the landscape using their key attributes simultaneously. This process is deductive and based on ecological theory and experience. We use observable differences in local physiography, soil factors and drainage, vegetation, forest history, and our understanding of their interrelationships to distinguish the types. It is a process that should give respectable results.Because UMBS ecosystems are highly disturbed, ground-cover species groups were the most important vegetative indicators used in distinguishing and mapping ecosystem types. Although we have distinguished and mapped ecosystem types to a relatively fine level of resolution, even finer differences were observed but not mapped. In some cases, types showing subtle differences of a given component were combined where they might have been split into two types. Work could still be done to refine boundaries and improve the resolution of the classification and map. Use of the classification and map by students and faculty will assist greatly in the refinement and changes that are appropriate. |
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