Patterns and processes of arthropod community succession after a fire.
BURGER, J.C.*, M.A.PATTEN, J.T.ROTENBERRY and R.A.REDAK
University of California, Riverside, CA 92521 USA 1
We surveyed arthropods after a disturbance by fire in southern California coastal sage scrub to investigate: (1) The degree to which arthropods had recolonized burned sites, (2) the pattern of post-fire succession across arthropod orders and guilds, and (3) the relative strength of patterns of recolonization between arthropod orders, families and guilds. We sampled vegetation and collected arthropods from 12 burned and 12 unburned sites using pitfall traps, malaise traps, and vacuum samples beginning three years after a fire. Arthropods were collected at three-month intervals over the course of two years and were subsequently counted and identified to family and guild. We associated families with the following guilds: Detritivore, herbivore, parasitoid, pollinator, predator, scavenger, and hematavore or vertebrate parasite. We found no significant difference between burned and unburned sites at the level of order or family, but burned sites had a distinct and predictable guild structure. Scavengers were most abundant and detritivores were among the least abundant in burned sites, whereas detritivores were significantly more dominant in undisturbed sites. This study supports results of an earlier study and strongly suggests that arthropod recolonization follows similar rules that vegetational succession does, as represented by changes in the importance of different functional groups or guilds at a site over time. In addition, results support the hypothesis that regional processes determine overall community structure, but local processes (such as disturbance by fire) determine the presence or absence of specific members of a community.
Keywords: fire, succession, arthropod communities, foraging guilds
This abstract is being presented at: 10:30 AM in session:
Poster Session #12: Disturbance Ecology.