Driftless ecology

Scientific

The [[driftless-area|Driftless Area]]‘s ecological distinctiveness traces directly to its geological history. While four major Pleistocene glaciations advanced and retreated across the surrounding upper Midwest between ~2.5 million and 11,700 years ago, ice never reached the [[driftless-area|Driftless]] interior. The land kept its pre-glacial topography — deeply incised stream valleys, exposed sandstone and dolomite bedrock, complex slope-aspect microclimates — that elsewhere in the region was buried under hundreds of feet of glacial till and outwash.

Six characteristic communities define Driftless ecology:

• Goat prairie — small dry-mesic prairie remnants on steep south-facing coulee slopes, kept open historically by Indigenous fire management and edaphic conditions. Big bluestem, little bluestem, side-oats grama, prairie dropseed; pasque flower, leadplant, prairie smoke, harebell. Most surviving examples are <10 acres.
• Oak savanna and oak openings — bur oak, white oak, black oak in widely-spaced groves over warm-season grasses. Once dominant across the Midwest interior; now reduced to small remnants. The [[driftless-area|Driftless]] holds some of the most intact remaining stands.
• Sand barrens — ancient terrace deposits along the [[batesville-ms|Mississippi]] support dry-sand-prairie communities with [[prickly-pear|prickly pear]] cactus, sand-barrens specialists. Spring Green Preserve is the most famous example.
• Hemlock-birch ravines — cool north-facing slopes hold relict boreal-affinity communities: [[eastern-hemlock|eastern hemlock]], yellow birch, Canadian yew, mountain maple. These are post-glacial relicts — the climate has warmed but the cool ravines remained habitable.
• Cold-water spring streams — hundreds of small spring-fed creeks drain the coulees. Cold, clear, gravel-bottomed; native [[brook-trout|brook trout]] in the headwaters, brown trout (introduced) downstream. The Kickapoo, Coon, Bad Axe, Black, [[viroqua|Wisconsin]] Dells streams are signature examples.
• Dolomite cliff and bluff — vertical exposures of Ordovician-and-Silurian dolomite host cliff specialists: walking fern, smooth cliff brake, bulblet bladderfern; [[timber-rattlesnake|timber rattlesnake]] (denning in cliff fissures); rough green snake; the diversity of land snails on [[driftless-area|Driftless]] bluffs is among the highest in North America.

Practical

Working with Driftless ecology means working at the intersection of farming and conservation that the region has been negotiating for a century. Streambank fencing, [[riparian-buffer|riparian buffer]] planting, contour strip-cropping (a [[driftless-area|Driftless]] innovation pioneered at Coon Valley in the 1930s by Aldo Leopold-influenced soil conservation experiments), and rotational grazing are the practical ecological-management vocabulary the region speaks. The Coon Valley project (1933) was the first large-scale watershed-restoration project in the United States — the template for the entire Soil Conservation Service approach that followed.

See also

Auto-generated from this entry’s typed relations: frontmatter, grouped by relation type so the editorial signal isn’t flattened.

• Contains: [[ridgeway-pine-relict]] · [[brook-trout]] · [[timber-rattlesnake]] · [[red-columbine]]
• Contained by: [[driftless-area]]
• Contains: [[brook-trout]] · [[driftless-area]] · [[red-columbine]] · [[ridgeway-pine-relict]] · [[timber-rattlesnake]]