Ecological Classification System Levels

Land Types are subdivisions of Land Type Associations.  The Minnesota DNR has not yet developed this level (the cost and utility of it will be determined in the future).  However, Land Types (LT) have been mapped on the Chippewa National Forest. In the Chippewa National Forest, land type mapping was based on: 

The Land Types within the Guthrie Till Plain in the Chippewa National Forest (Figure 26) will be used as example. 

                                         Figure 26

Northern hardwoods, particularly sugar maple, are very competitive and would dominate the landscape in the absence of frequent catastrophic disturbances.

Land Types are named using the most predominant cover type historically and it's accompanying sensitivity to fire. Land Types are arranged in distinct zones based on historic fire frequency and severity, even though fire suppression activities have been in effect for 75 years.  The frequency and severity of fire is used here as an indicator of moisture availability.   Fires typically did not originate in the Guthrie Till Plain, but traveled into the area from the  Bemidji Sand Plain LTA to the north, and west.  The Bemidji Sand Plain was historically a fire prone ecosystem; ground fires occurred every 10 to 25 years and stand replacement (crown) fires every 50 to 100 years.  When a fire reached an island of the Guthrie Till Plain it would burn into the island and eventually go out.  How far the fire went varied depending on the moisture conditions and the abundance of wetlands. 

The  Fire Dependent Mixed Pine-Hardwood Land Type (Figure 27), is immediately adjacent to the Bemidji Sand Plain.

                                                    Figure 27

It burned most severely and frequently. This is because the upland soils are dry. 

The Fire Tolerant White Pine-Hardwood Forest and Fire Tolerant Boreal-Hardwood Conifer Forest land types are shown in Figure 28; the historic fires here were less intense and less frequent here (ground fires and stand-replacement fires every150 years or 250 years respectively).

                                        Figure 28

This is because  the upland soils are somewhat moist. 

The Fire Intolerant Land Types in the south central and eastern portions (Figure 29), rarely burned because the soils are moist.

                                         Figure 29

They were protected not only by the Fire Dependent and Fire Tolerant types but also by the abundant wetlands that occur in them and by Leech Lake. The unit is dominated by old growth sugar maple and basswood forests in large, adjoining uneven-aged stands.  Yellow birch, paper birch, and northern white cedar forests occur with maple-basswood communities on lower lying sites.  There is abundant wood debris on the forest floor, creating diverse vegetation communities.  Many wildlife species can be found here including species which prefer wet, mature forest conditions with heavy forest floor debris and no disturbance.  For example, species such as the red-backed vole, woodland jumping mouse, and northern flying squirrel are common. 

The Land Type level is useful for landscape scale planning on administrative units.

                                             go to Land Type Phases