Arboreal Arthropod Diversity in Woodlands. II. The Pattern of Recovery of Diversity of Melaleuca linariifolia Following Defaunation

The level and form of isolation of arthropod faunas occupying individual trees of the endemic species Melaleuca linariifolia in woodlands near Sydney, Australia, were studied. The recovery of arthropod faunas following defaunation with insecticide in one of each of 21 pairs of trees was monitored. Common species recolonized within 2 weeks. The number of species present recovered to pre-spray levels within 16 weeks. Relatively sedentary species and rarer species reappeared at similar rates. Total numbers recovered within 8 weeks. Evenness recovered in the first 2 months, but continued to diverge from that in unsprayed trees through the end of the study period. Continued control tree divergence in evenness, as well, suggests only a partial isolation of a tree fauna from communities on other trees. Community structure in the sprayed trees was still seriously disrupted after 1 yr. Colonizing species were no more similar to the original fauna of the tree than they were to the fauna of unsprayed control trees. Trees are neither isolated entities, nor part of a fully integrated community. Scale appears to be important in estimating biodiversity dynamics in these woodlands.