Land Use Lesson 5 - Analyzing Land Use Changes : State

Individuals and groups of people become engaged in land use issues within the local community. Governmental agencies, such as planning commissions, zoning boards, and zoning boards of appeal, address the proposed changes and conflicts that arise at the local level. These are local issues. Other land use decisions, made by state elected representatives and government agencies, are not local for most people. They include things like land use in the state forests, building roads, using water, extracting minerals, and fishing on state land and waters. Those are important land use issues for the entire population of the State of Michigan. Proposed changes often undergo scientific studies to determine their impact and to gather evidence supporting either an approval or disapproval recommendation for a particular land use.

Land use information is available for the State of Michigan. One set of data that is very useful for the study of longer-term trends in land use is the U.S. Census of Agriculture. The Census was taken every 10 years between 1840 and 1920 and then every 5 years between 1925 and 1974. Until 1950 the agriculture census was taken at the same time as the censuses for population and housing. Between 1954 and 1974 the Agricultural Census was taken in years ending in 4 and 9, then changed in 1978 to be taken during years ending in 2 and 7. This final change made the Agricultural Census coincide with the Economic Census, which covers things such as manufacturing, mining, construction, and retail trade. The data are important for scientific study since they were collected using criteria that assure comparability through time, and especially for agricultural census data from 1975 through 2007 when more that 98% of Michigan farms were included in the census.

The scientific analysis of trends in agricultural land use reveals effects on other lands and their uses as well. For example, during the decade from 1990 until 2000, the Michigan population remained stable, but land use for residential purposes expanded significantly. The land use trade-off was agriculture land for suburban development, and farm fields for suburban residential and commercial development. This trade-off has resulted in urban sprawl that is consuming Michigan’s agricultural land at an alarming rate. The trend has consequences for more than diminished agricultural production capacity. The consequences also include changes in roadway networks, commuting patterns of workers, demands placed on school districts, the delivery of services such as water and sewer, and the attachment to community.

Trend lines on graphs do not always have a straight line in one direction. They increase and decrease from year to year, but the trend should be considered for the long period. If the overall trend is decreasing, even though there may be an increase for the last period, the projection of the line on the graph will normally continue downward. In agriculture, the trend line increased in the period from 1997 to 2002 because of a change in the classification for farmland. However, the trend over the long period has been for less agricultural land in Michigan and that is the most likely trend to continue into the future. This is a challenging concept for students, and they need to be alerted to the fact that many trend lines they see on graphs have been smoothed so that there are no abrupt increases or decreases. However, data shown in this lesson are the actual census data. We know that there is a continuing loss of farmland in the state as land use changes occur in both the Lower and Upper Peninsulas. This leads one to project that Michigan’s farmland is currently decreasing and will continue to decline.

Note: There are a number of reasons why a trend line may change direction for a short period amidst a long-term decline or increase. The period 1974- 1982 is an example of a slight increase when the trend is definitely down over the long term. The explanation for this is often complicated. In this case the explanation seems to rest with a change in the definition of a farm that was introduced in the 1974 Census. The technical definition was rewritten to define a farm as any place where $1,000 or more of agricultural products were produced or sold during the calendar year.

The slight increase beginning in 2002 seems to be explained by the 1998 Farmland Preservation Program. This is an example of a government program designed to encourage good land stewardship as well as retain land in agricultural use.

The axes for the graph are millions of acres of land and years. Lines have been put there for the students to label. However, note that the axes do not start at zero; this is important to point out to students if their experience has always been with the axes starting at zero. In this activity the students are working in big numbers—millions of acres—and to start at zero would mean that the increments would be much too small to get to 10,350,000 acres total for the state.

Students may ask about the problem of food shortage as land is taken from agriculture for other uses. This is a good question and should be addressed when it arises. Explain to students that with less agricultural land Michigan’s food production could stay the same because more food could be produced on the land that remains in farming than is currently produced. This is called crop yield. On the other hand, if crop yield remains the same, then Michigan would have to develop new agricultural lands from forests and wetlands in order to produce the same amount of food. There is yet a third major factor that students should discuss. Much of the food that people consume in Michigan is currently grown in other states and other countries. As long as we are able to import food to Michigan, there will be enough food available.