Palaeoendemic invertebrates weakly reflect palaeoendemic plants across a 52-year-old fire boundary

Abstract

If palaeoendemic invertebrates depend on palaeoendemic plants, and the latter are threatened by an increase in fire incidence, there is a possibility of an extinction cascade. We test whether there is co-occurrence of palaeoendemic plants and invertebrates in the proximity of a 52-year-old fire boundary in subalpine Tasmania, Australia. We used 2 × 2 m quadrats to record the incidence and cover of vascular plants and trapped invertebrates at each of these 33 sites in six time periods using an alpine Malaise trap and a CD sticky trap. The number of co-occurrences of palaeoendemic plant taxa with palaeoendemic invertebrate taxa was greater than expected by chance (p = 0.020), but many palaeoendemic invertebrates co-occurred with non-palaeoendemic plants. Some of the palaeoendemic invertebrate taxa that were associated with palaeoendemic plants were monophagous, while others were associated with environmental conditions created by a long absence of fire. Many may be threatened if increasing fire incidence destroys vegetation dominated by palaeoendemic plants.