Nebraska sedge (Carex nebraskensis Dewey): Phenology and life history at Tule Meadow, Sierra National Forest, California

Abstract

To better understand shoot development and population dynamics of Nebraska sedge (Carex nebraskensis Dewey), a valuable mountain meadow forage species, 766 shoots were tagged and studied at Tule Meadow, on the Sierra National Forest, California. A key to its vegetative and reproductive phenologic stages was developed. New shoots emerged throughout the growing season, but mostly in spring. Spring shoots reached the mature vegetative stage before autumn. Late summer and autumn shoots overwintered in juvenile vegetative stages. About 3% of each year's cohort of shoots died as juveniles. Early emerging shoots passed at least 1 winter but late emerging shoots passed at least 2 winters before flowering. Among shoots reaching the mature vegetative stage, 60% eventually flowered and died. An average of 90% of the vegetative shoots alive each autumn survived winter. A few shoots remained vegetative and had long lives—1 shoot was still alive after 7.5 years. Vegetative shoots (those not becoming reproductive) of the 1980 and 1981 cohorts lived an average of 599 +/- 50 days. Shoots that became reproductive (flowered) lived an average of 631 +/- 17 days, and time from shoot emergence to culm elongation averaged 501 +/- 18 days. Nebraska sedge appears well adapted to grazing by having long-lived vegetative shoots that can produce new herbage for several years. Nevertheless, grazing management should strive to maximize the numbers of shoots in spring because they are the ones that can flower the next season.