Growth and reproductive responses of true mountain mahogany to browsing
Issue Date
2003-11-01Keywords
compensatory growthplant growth
Utah
Cercocarpus montanus
browsing
twig demography
utilization
grading optimization
herbivory
shrubs
mountain brush
exclosures
Cercocarpus montanus
Metadata
Show full item recordCitation
Turley, D., Roundy, B. A., & Walker, S. C. (2003). Growth and reproductive responses of true mountain mahogany to browsing. Journal of Range Management, 56(6), 591-599.Publisher
Society for Range ManagementJournal
Journal of Range ManagementAdditional Links
https://rangelands.org/Abstract
True mountain mahogany (Cercocarpus montanus Raf.) compensates for annual growth lost to browsing under conditions of high resource availability. To develop better guidelines for its management for big game winter forage, twig demography was studied under natural herbivory and resource availability inside and outside exclosures at 1 site in the Wasatch Mountains and on 4 sites on the North Slope of the Uinta Mountains, Utah. Annual and previous years' twig lengths, as well as location and numbers of flowers and seeds were diagrammed on branches of browsed and unbrowsed shrubs in the spring or summer and fall between 1996 and 1999. Annual twig growth and flower and seed numbers of both browsed and unbrowsed shrubs were greatest in 1997 or 1998 when precipitation was highest. Utilization of annual growth varied among sites within a year and among years within a site and ranged from < 21 % to > 300 % when previous years' growth was browsed. Despite differences in utilization, browsed twigs compensated similarly for length lost to herbivory, so that total twig lengths remained the same over the course of the study. Although twigs on unbrowsed shrubs had less annual growth per unit branch length than those on browsed shrubs, lack of length lost to herbivory resulted in an increase in total twig length over time. Years of high resource availability are important in allowing grazing tolerant shrubs such as true mountain mahogany to compensate for years of heavy utilization. Flower and seed numbers were much higher (P < 0.05) on unbrowsed than browsed shrubs. Compensatory growth was enough to maintain, but not increase total twig lengths after high utilization (> 100 %) even on years of high resource availability.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2307/4003933