Do fire and seasonality affect the establishment and colonisation of litter arthropods?

Abstract

In tropical ecosystems, the influence of fire can have dramatic effects on the arthropod community and some taxa may take a long period to recover after such disturbance. Here we investigated the effects of an accidental fire on the reestablishment of litter arthropods and compared it with a control/unburned area. Seasonal data were also included in the analysis, as the rupestrian fields (transition between Brazilian savanna and Atlantic forest) have two well-defined seasons and arthropod populations tend to fluctuate accordingly. Our study commenced 4 months after fire and during the 2 years afterwards, we found 19 arthropod groups in the litter, of which flies, springtails, spiders, beetles, true-bugs, harvestmen, grasshoppers, hymenopterans (except ants), mites and roaches were the most representative. The unburned area hosted over 60 % of the total arthropod abundance and only true-bugs were significantly more abundant in the burned site, the other arthropods remained, in general, more abundant in the control/unburned area throughout the study. Arthropod abundance was threefold-higher in the rainy season. Arthropods were able to recolonise the burned area soon after the fire event, but their abundance was low during the 2 years of study, revealing that fire effects can extend for long periods. We conclude that, despite rapid plant resprouting and arthropod colonisation after fire, 2 years were not enough for the full reestablishment of litter arthropods.