Tussock Meadows in Southeastern Wisconsin

The vegetation and environmental conditions of tussock meadows in southeastern Wisconsin were studied during the summers of 1929, 1932, and 1933. 2. Tussock meadows are developed along stream and pond margins, on springy hillsides, and in drained morainic depressions. They are found on soils showing a high percentage of organic matter. 3. Tussock meadows are dominated by a single species, Carex stricta, which produces tussocks that consist of a tuft of leaves and culms at the summit of a pedestal composed of roots, rhizomes, soil, and vegetable debris. 4. New tussocks are initiated by means of rhizomes which grow horizontally from the bases of old tussocks. 5. Individual tussocks may attain a height of 2 to 4 feet and a diameter of 8 to 30 inches. They may persist in an area for many years. 6. The leaves of Carex stricta show certain xeromorphic structures which indicate an adaptation to the excessive evaporation rates to which they are occasionally subjected. The roots and rhizomes show hydromorphic structures which indicate an adaptation to extremely moist conditions. 7. The tussock habit enables Carex stricta to persist in areas where the water level shows a marked seasonal fluctuation. 8. The tussock association is almost exclusively herbaceous. The most important secondary species are grasses and sedges. Dicotyledonous herbs may dominate in appearance but not in numbers at certain seasons. 9. Carex stricta furnishes marked competition for herbaceous species from the standpoint of both aerial and subterranean organs. 10. Progressive decrease in soil moisture and lowering of the water table lead to invasion by species of lower moisture requirements and the ultimate disappearance of the tussock association. 11. In succession, the tussock association is usually preceded by a reed-swamp stage and followed by a sedge-rush stage. The association may be invaded by willows which are eventually succeeded by a swamp forest. 12. Evaporation, annual fires, and soil reaction are not significant factors in succession. 13. Overgrazing may result in the disappearance of the tussock association and the appearance of grassland in its place.