FORESTRY HANDBOOK For Laurentian Upland North Biophysical Region Itasca County, Minnesota April 2006 I. Background The purpose of this “Forestry Handbook” is to provide managers and foresters with a ready reference that described in detail the environment of each biophysical region and opportunities for producing quality consumptive and non consumptive products. Contents of this handbook are intended for integrating with proven silviculture principles and practices during the preparation of prescriptions for strategic and project activities. Users of this reference can analyze and evaluate a specific area of forestland and determine its capacity for supporting a proposed use. The reference can also be used for screening large areas of forestland for its capacity for supporting individual uses or combination of uses. Managers and foresters can then make decisions and prepare prescriptions that will have highly predictable results for producing sustainable products, maintaining site quality and substantially reducing risk of any adverse impacts. Each handbook is comprised of description of the biophysical region, description of each biophysical landscape ecological unit (BLEU), an analysis of biophysical information and presentation of opportunities for managing forestland. II. Laurentian Upland North Biophysical Region Introduction The Laurentian Upland North (LUN) biophysical region occupies 241,112 acres of which 72,567 are County forestland in the east central portion of Itasca County and is bordered on the north by Bigfork-Cook Plain biophysical region and on the south by Mesabi Region. A major portion of the population of Itasca County is located near and in the Mesabi Iron Range adjoining LUN. A significant portion of citizens living in LUN is employed in Iron Range industries or supporting businesses. Active and abandoned farmsteads in the LUN are rather common near the Range and add contrast to vegetation that includes hay fields, brushy fields, fields with scattered trees and forest. A majority of rural, town and city population is located within 10 miles of the Iron Range. State highway 65 is the main north to south route and State highway 169 is the main west to east route through the area. Those State highways combined with county and forest roads provide an effective all season transportation system within LUN. An enormous amount of local commerce is moved over that system. Airports at Hibbing (east of LUN) and at Grand Rapids (south of LUN), Minnesota provide all season air transportation capabilities for the area. Iron World and Hockey Hall of Fame are located near LUN and generate a significant volume of tourist traffic and visitors to the area. Within this LUN is portion of the George Washington State Forest. Climate Climate in Laurentian Upland North biophysical is continental and air masses flowing north in the Mississippi Valley and those flowing south from Canada are major contributors to climate and local weather. Extremes in local weather occurring over a short time in both winter and summer are characteristic of LUN. Average annual precipitation is 29 inches of which 15 inches occurs in May through August. Average annual temperature is 36 degrees and average May through August is 59 degrees. Estimated growing degree days are 3000. Climate data are based on certified weather stations located in the general area. Laurentian Upland North biophysical region is located immediately north of the Laurentian Divide that is a bedrock ridge oriented east to west. Extreme low winter temperatures frequently occur along the north side of the Divide due to the collection of cold air flowing south from Canada. Record low temperatures have been recorded in that area. Because of numerous significant changes in local relief, distinct deep glacial channels and local obstacles to airflow, there are many chances for microclimate departures from region weather patterns. Those glacial channels are pathways through which chilling winter air flows from “trap” created by the northwest to southeast oriented elongated glacial ridge that forms the boundary between the LUN and Bigfork-Cook Plain biophysical region to the north. This biophysical region could 1 have the greatest variation in climate and local weather in Itasca County. Table 1 is a summary of temperatures recorded at each sample point within a biophysical plot. Table 1 Temperatures Month t1 t2 t3 t4 June 66* 67 57 52 7 8 4 4 80 96 72 65 49 51 46 42 151 151 150 145 July 70 71 61 57 8 9 6 4 92 100 105 70 49 49 48 44 429 429 429 429 August 68 68 61 57 7 8 4 4 86 103 76 67 53 53 53 50 372 372 372 372 *t1 is temperature 4.5 feet above ground, t2 is temperature 1/8 inch above litter layer, t3 is temperature at contact of litter layer and mineral soil and t4 is temperature 20 inches below t3. Glacial Geology Glacial earthen materials from the Des Moines and Rainy lobes prevail in Laurentian Upland North biophysical region. Most common landforms in the region are moraine, till plain, outwash plain and glacial stream channels. In the northeastern portion of LUN there is evidence that short duration glacial lakes altered the land and was a major factor in shaping the present glacial landforms. Water in those lakes contributed to breaching of the moraine near the border of LUN with the adjoining Bigfork-Cook Plain biophysical region resulting in deep stream channels of limited extent. Enormous volumes of glacial earthen material were eroded with the breaching of the moraine resulting in extensive down stream sedimentation. That breaching set the stage for the continuing present day cutting of stream channels. Present streams flowing east and north in those channels contribute water to the Rainy River watershed. Representative earthen materials include thick accumulation of sandy, loamy and clayey deposits that are frequently more than fifty feet thick. Materials from the Des Moines lobe characteristically have elevated levels of nutrients and gray silt and clay. In contrast, Rainy lobe deposited yellow and brown sandy and loamy materials with lower level of nutrients. There are extensive areas within LUN having several feet of sandy and loamy materials underlain with gray clayey material. Near the contact of LUN and the Laurentian Divide there are local red loamy and clayey materials, believed to be from Lake Superior lobe, that were incorporated with either the Des Moines or Rainy materials. There is an abundance of sandy and gravelly earthen material in LUN. At a given location the material can vary from silty, clayey to sand and gravel within a depth of twenty feet. 2 Terrain Extensive plain combined with low rolling hills, hills with shallow glacial earthen material underlain with bedrock, distinct glacial stream channels and scattered open pit mines (near Laurentian Divide) result in a forestland with many contrasting features. In specific locations, glacial streams breached moraine hills that created steep walled channels that persist today. Lakes are scattered somewhat throughout the region and appear in arc pattern in northeastern portion of region. Present day lakes resulted from a combination of deep depressions caused by melting of buried ice blocks in glacial earthen material and collection of runoff in stream valleys dammed with glacial earthen materials. Local hills and ridges with shallow glacial drift underlain with bedrock express irregular somewhat angular slopes. Geological erosion of the parent bedrock has formed the present shape of the forestland. Rounded and sub-angular rocks are found throughout the region and the more angular rock is found in areas where depth to bedrock is typically less than 5 feet. Vegetation Present vegetation in the Laurentian Upland North biophysical region is the combined result of thousands of years of response to natural disturbances, climate change and disturbances caused by indigenous cultural followed by decades of activities by European settlers. Natural disturbances included fire, insect infestations, high velocity wind and grazing of various mammals that inhabited the prairie and forestland. In LUN were indigenes that frequently burned extensive areas encourage local grazing of mammals that they used for food. They also used fire for control of insects and as an element of war. Larch sawfly disseminated tamarack in recent history and now it has recovered is covers hundreds of acres. Balsam fir was severely impacted by the spruce budworm. American elm has been disseminated by Dutch elm disease and appears to be incapable if surviving the epidemic and may be eliminated from the LUN. White pine succumbed to white pine blister rust and is currently there is limited natural regeneration and selected organizations are planting it to increase its present in forestland. European settlers converted forestland to farmland for growing of food crops for themselves and farm animals. They used the wood for building structures, heating homes, fence posts and wooden fences. They introduced plants for food production and aesthetic purposes and many remain in current plant communities. There was also extensive removal of wood products to support the buildings necessary to support growth of local towns connected to the mining of iron, timbers in mines, ties for railroads and for construction of buildings in growing population centers beyond the immediate region. During and following the removal of wood products, there were forest fires that burned large areas of forestland at varying intensities that strongly influenced the resulting plant communities. The combined result of all those impacts and disturbances of the vegetation in LUN is a forestland that comprised of rich biophysical variability, highly contrasting plant communities and an abundance of habitat diversity. Immediately following the retreat of the glacier the tundra developed followed eventually by the present boreal forest that is near its southern boundary and adjoining hardwood forest. Trembling aspen is most common broadleaf tree and balsam fir is the most common conifer.