Southwest Savanna Landscape

Map showing the Southwest Savanna Ecological Landscape

General Description

The Southwest Savanna Ecological Landscape is located in the far southwestern part of the state. It is characterized by deeply dissected topography, unglaciated for the last 2.4 million years, with broad open hilltops and river valleys, and steep wooded slopes. The climate is favorable for agriculture but the steep slopes limit it to the hilltops and valley bottoms. Soils are underlain with calcareous bedrock. Soils on hilltops are silty loams, sometimes of shallow depth over exposed bedrock and stony red clay subsoil. Some valley soils are alluvial sands, loams, and peats. Some hilltops are almost treeless due to the thin soil while others have a deep silt loam cap.

Vegetation

Historic vegetation consisted of tall prairie grasses and forbs with oak savannas and some wooded slopes of oak. Almost three-quarters of the current vegetation is agricultural crops with lesser amounts of grasslands, barrens, and urban areas. The major forest types are oak-hickory and maple-basswood. High-quality prairie remnants occur on rocky hilltops and slopes that are not farmed. Some prairie pastures and oak savannas still exist. The grassland areas harbor many rare grassland birds, invertebrates, and other grassland species. Relict stands of pine occur on bedrock outcroppings along some stream systems.

Hydrologic Features

Warm-water streams flow throughout the landscape and include the Pecatonica and Galena Rivers. Some contain rare aquatic species. No natural lakes occur in the Ecological Landscape. Although the lakes that are present are the cleanest in the state, the watersheds and streams are ranked as relatively polluted according to the Wisconsin DNR.

Land Use

The total land area for the Southwest Savanna Ecological Landscape is approximately 1.2 million acres, of which only 11% is classified as timberland. Less than 1% of the Ecological Landscape is in public ownership.

Socioeconomics

Socioeconomic data are summarized based on county-level approximations of the Ecological Landscape (referred to as a "region"). Economic data are available only on a political unit basis with counties as the smallest unit. The counties included in this socioeconomic region are Dane, Grant, Green, Iowa and Lafayette ("Southwest Savanna Region"). Although less than 25% of Dane County lies within this Ecological Landscape, and none of the Madison Metropolitan area, it was included in the socioeconomic region. This may cause some discrepancies when analyzing the socioeconomic structure of the ecological landscape. However, the social and economic character of the Ecological Landscape and its residents may be significantly impacted by Madison's proximity. This region is highly dependent on agriculture. It has a greater percentage of farmland than any other region and the highest market value per acre of agricultural products sold. (Farmland includes all land under farm ownership such as cropland, pastureland, and woodland.) The counties of the Southwest Savanna Region rank second in milk production per acre and first in corn production per acre. Although much of the land is in agriculture, it is somewhat less intensive than in other parts of the state, including large pastures and many Conservation Reserve Program lands. Compared to other Ecological Landscapes, the acreage in lakes is low, as is the number of fisheries and wildlife areas. The percentage of timberland being sold and diverted to other uses is higher than in any other region. Wooded slopes are often managed for oak-hardwood production. In some cases oak forest is being replaced with cherry, red maple, and hickory due to fire suppression, harvest methods, and invasive shrub competition. The population of the Southwest Savanna Region is racially diverse and well educated. The population density (100 persons/sq. mile) is slightly greater than that of the state as a whole (96 persons/sq. mile). Of all the regions, it has the smallest percentage of elderly (over 65) and the second highest percentage of nonwhites (African-American, Hispanic and Asian). The number of high school and college graduates is second highest in the state. There is a relatively high per capita income and low rates of both poverty and unemployment. The government sector is stronger in this region than any other part of the state and manufacturing is not a strong employer. (The demographic and economic information for this region is significantly impacted by including Dane County.)

For any questions regarding the maps presented on this site or the "DNR Ecological Landscapes of Wisconsin" handbook, please contact Jeff Schimpff at Jeff.Schimpff@wisconsin.gov. Suggested Citation for Handbook: Wisconsin Department of Natural Resources. In Prep. DRAFT Ecological Landscapes of Wisconsin. State of Wisconsin, Dept. of Nat. Resources, Handbook. 1805.1. Madison, WI.

Last Revised: Thursday February 08 2006