Growth, fire history, and browsing recorded in wood rings of shrubs in a mild temperate climate.
Ecology
; 92(5): 1020-6, 2011 May.
Article
en En
| MEDLINE
| ID: mdl-21661563
ABSTRACT
Separate effects of abiotic and biotic factors on the structure and dynamics of ecological communities may be recorded in growth rings of woody plants. We used Ceanothus cuneatus rigidus and Arctostaphylos pumila to tease apart the roles of fire, rain, and herbivores on the histories and community structure of four areas in a coastal mediterranean-type climate in central California with mild winters and mild summers. Ring widths of both species were related to rainfall in two of the areas; heavy deer browsing on Ceanothus overwhelmed the climate signal in the others. Ceanothus germination was more closely related to heavy rainfall, especially during ENSO years, than to fire events. In a related greenhouse experiment that evaluated these observations, the same proportions of new Ceanothus seeds germinated after burning and after receiving regular water for several months, but germination of old seeds responded primarily to the fire treatment. In areas where heavy browsing by mammals reduces recruitment and growth of Ceanothus and increases mortality, the continuance of the Ceanothus population must rely heavily on germination from the persistent seed bank during unusually wet years or after occasional fires. Because Arctostaphylos can produce new stems from underground roots, individual plants may survive and produce seeds until another fire.
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Bases de datos:
MEDLINE
Asunto principal:
Clima
/
Arctostaphylos
/
Ceanothus
/
Incendios
País/Región como asunto:
America do norte
Idioma:
En
Revista:
Ecology
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos