Land Use:
(Click image to enlarge)
|
|---|
Trends10.JPG
27.69 KB | |
Topics related to land use trends.
|
Trends11.JPG
104.68 KB | |
The pattern of development (at least 2 people per square mile) was confined to the East coast through 1770, then to the Ohio River valley through 1810.
By 1850, most of the forest lands east of the Mississippi were settled, and by 1890, the prairies too.
Some prairie counties now have below 2 people per square mile, with continuing population loss.
Turner MG, Carpenter SR, Gustafson EJ, Naiman RJ, Pearson SM. 1998. Land Use. Pages 37-61 in Mac MJ, Opler PA, Puckett Haecker CE, Doran PD. Status and trends of the nation's biological resources. U.S. Department of the Interior, U.S. Geological Survey, Reston, Va.
|
Trends12.JPG
60.06 KB | |
The pattern of settlement is also apparent in the changes in land cover since 1840.
Forests were converted to farmland first ("if it can't grow a tree, it probably can't grow crops" was common early impression).
Grasslands very rapidly converted once the moldboard plow was perfected.
Urbanization has been major conversion in recent decades.
Turner MG, Carpenter SR, Gustafson EJ, Naiman RJ, Pearson SM. 1998. Land Use. Pages 37-61 in Mac MJ, Opler PA, Puckett Haecker CE, Doran PD. Status and trends of the nation's biological resources. U.S. Department of the Interior, U.S. Geological Survey, Reston, Va.
|
trends13.JPG
51.03 KB | |
Iowa is 'winner' with respect to the percentage of its natural lands converted to other uses - only 8% is in Kuchler's potential vegetation type.
Illinois next with 11%, Ohio has 25%.
Major conversion occurred in last half of 19th century in the Midwest.
Klopatek JM, Olson RJ, Emerson CJ, Jones JL. 1979. Land-use conflicts with natural vegetation in the United States. Environmental Conservation 6:191-200.
|
trends14.JPG
106.18 KB | |
These are some principles that tend to hold when humans convert landscapes.
1. access is critical.
2. habitats are resilient when not overly disturbed.
|
trends15.JPG
114.06 KB | |
3. native habitat is fragmented and lost during conversion.
4. exotics often invade during conversion.
5. the matrix around habitat in question often is critical to amount of overall impact.
August P, Iverson LR, Nugranad J. submitted. Human conversion of terrestrial landscapes. in Gutzwiller K, editor. Concepts and applications of landscape ecology in biological conservation. Springer-Verlag, New York.
|
trends16.JPG
82.74 KB | |
Fragmentation has been studied in many ways. Kurt Riitters and colleagues have done a lot of work assessing global and U.S. fragmentation. I encourage you to go to his site to check out their work.
http://www.srs.fs.fed.us/4803/landscapes/
We have done some work in Ohio, assessing forest fragmentation in each 10 x 10 km block across the state.
This shows percent forest is highest in southeast, lowest in northwest.
Iverson, L.R. and A. Prasad. 2001. Assessment of fragmentation in Ohio. unpublished document
|
trends17.JPG
75.92 KB | |
If you remove the outside 100 m from each forest patch, you get 'core' area - which has been linked to e.g. forest interior birds.
Much less of the state qualifies as having a high percentage of its forest as core.
|
trends18.JPG
74.69 KB | |
Forest classification was done with Landsat TM (30 m data) in 1985 and 1994, with the percent change shown here.
Keep in mind that there was classification error in each, compounded when overlaying two dates.
Shows general increase in forest along east side, and little change elsewhere.
|
trends19.JPG
81.92 KB | |
Changes in core area of forest show significant increases in some southern and southeastern grids.
Some of this could be regrowth of harvested lands (going from shrub type to forest type in the classification).
Some areas around Cleveland show losses of core area.
|
RWU NE-4153, USDA Forest Service, Northeastern Research Station, Delaware, Ohio, USA
Delaware, OH Home
