Cercocarpus montanus

Alderleaf Mountain Mahogany

Rosaceae

The Basics

Taxonomy: Kingdom - Plantae (plants). Subkingdom - Tracheobionta (vascular plants). Superdivision - Spermatophyta (seed plants). Division - Magnoliophyta (flowering plants). Class - Magnoliopsida. Subclass - Rosidae. Order - Rosales. Family - Rosaceae (rose). Genus - Cercocarpus Kunth. Species - Cercocarpus montanus Raff.

Ecology: True mountain-mahogany is a shrub or less often a small tree 1-7 m tall. Dayton suggests that on "favorable" sites true mountain-mahogany can assume small tree stature. Few to many branches are produced, and the form is erect to spreading. Stems measure 0.5-5 cm in diameter and are sturdy and stiff. The main stem is typically less than 80 cm in diameter. Researchers noted lignotubers on some shrubs in Nuttall's shrub oak-dominated chaparral vegetation in southern California. True mountain-mahogany bark is thin and smooth. True mountain-mahogany is considered long-lived...Deciduous, persistent, "mostly deciduous," and "occasionally evergreen" are all used to describe true mountain-mahogany. Deciduousness is latitude and/or variety dependent. True mountain-mahogany grows best in full sun, tolerates early-seral site conditions, and is dominant in several late-seral or climax communities. For additional information on late-seral or climax communities where true mountain-mahogany is dominant. Following disturbances in areas where true mountain-mahogany is established, colonization by this species is rapid...In southern California's San Sevaine area, true mountain-mahogany occurs in both pioneer and mature alluvial scrub vegetation.

Threats

Fire Effects: Often true mountain-mahogany is top-killed by fire. However, true mountain-mahogany quickly recolonizes burned sites through root crown or rhizome sprouts. Postfire sprouting is described as "vigorous" and "rapid" and is common under a range of fire regimes. True mountain-mahogany seed is typically killed by "intense" heat, and seedlings are rare in early postfire communities...Often true mountain-mahogany is top-killed by fire. However, true mountain-mahogany quickly recolonizes burned sites through root crown or rhizome sprouts. Postfire sprouting is described as "vigorous" and "rapid" and is common under a range of fire regimes. True mountain-mahogany seed is typically killed by "intense" heat, and seedlings are rare in early postfire communities.

Reproduction

Seed production - Flowers are wind-pollinated...True mountain-mahogany is monoecious...Unbrowsed true mountain-mahogany shrubs produced many more flowers and seeds than browsed shrubs in the Wasatch and Uinta mountains of Utah. Flower and seed production for both browsed and unbrowsed shrubs were greatest when precipitation was greatest.

Seed dispersal - Seeds are dispersed by wind and small mammals. Wind-dispersed seed can travel up to 140 m from the parent plant. High-quality true mountain-mahogany seeds are typically those 1st detached from the plant. Seed shed earliest may be most vulnerable to predation.

Seedling establishment/growth - Successful true mountain-mahogany seedling establishment is often correlated with adequate moisture. In chaparral communities, seedling establishment is sporadic and likely restricted to high moisture years. Seedlings are vulnerable to frost and drought, and on harsh sites, establishment occurs only during "favorable" conditions. Vegetative regeneration - True mountain-mahogany regenerates through asexual means following aboveground stem removal from browsing and/or fire; however, asexual sprouting also occurs in the absence of aboveground damage.

Species Distribution

Citation

USDA Plants Database
USDA, NRCS. 2016. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.

USFS Plant Database
Habeck, R. J. 1992. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.