INDIRECT INTERACTIONS MEDIATED BY CHANGING PLANT CHEMISTRY: BEAVER BROWSING BENEFITS BEETLES

摘要: We documented an indirect interaction between beavers (Castor canadensis) and leaf beetles (Chrysomela confluens), mediated by changing plant chemistry of their cottonwood hosts (Populus fremontii 3 P. angustifolia). Resprout growth arising from the stumps roots beaver-cut trees contained twice level defensive chemicals as normal juvenile growth. However, rather than being repelled these defenses, were attracted to resprout growth, resulting in a strong positive association beetles. Why? Cottonwoods contain phenolic glycosides, that are against mammalian herbivores, but sequestered used for own defense. Experiments showed fed better defended predators those nonresprout There also may have been nutritional benefit, because conversion plant's defense, salicin other salicylaldehyde releases glucose. Also, more total nitrogen did Transfer experiments that, apparent response increased benefits, developed faster weighed at maturity. Although interactions much less studied direct interactions, our work suggests beaver cutting cottonwoods important consequences organisms could represent component community structure. The habitat mosaics created herbivory increase arthropod biodiversity benefit such birds mammals. Furthermore, stimulating production play role regeneration type is rapidly vanishing West.