A population of Hemideina crassidens (the Wellington tree weta) was monitored over a 4‐year period after the eradication of Rattus exulans (the Polynesian rat kiore) and Gallirallus australis australis (the South Island weka) from Nukuwaiata (Chetwode Islands), Pelorus Sound, New Zealand. A novel survey technique (entrance scores) was used in combination with a conventional technique (random searches for active weta) to measure changes in weta population parameters after the removal of predation pressure and to investigate impacts of exotic predators on tree weta. Tree weta density did not increase markedly over the 4‐year period, but the proportion of active adults did increase. Weta were observed to move into larger and more crowded galleries (refuges), to occupy galleries closer to the ground, and to spend less time sitting in gallery entrances. It was concluded that endemic tree weta are well adapted to withstand some introduced vertebrate predators but are able to live a more “relaxed” lifestyle in the absence of this predation. The most significant change detected was in weta age structure, with adults increasing their proportion of the population.

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Biodiversity studies are often limited by unavailability or inaccessibility of taxonomic expertise; in New Zealand, taxonomic revisions and keys to many invertebrate groups are far from complete. To make progress with ecological and biodiversity studies, the separation of organisms into recognisable taxonomic units or morphospecies has sometimes been adopted. Coleoptera are speciose, trophically diverse, and taxonomically well known compared with other large trophically diverse groups and so they are useful to include in biodiversity studies. This study opportunistically examined the accuracy of Coleoptera species separation using morphologically recognisable features of specimens collected from three different vegetation communities, by three student researchers with different levels of training and previous expertise. Their morphospecies were examined by a single researcher with experience in taxonomy of Coleoptera. In total, 155 morphospecies were separated by the three students, compared with 151 determined by the specialist, which included representatives from 23 families of Coleoptera. All three students identified a total number of morphospecies within about 10% of the actual number, irrespective of previous training. However, the proportion of correct species separation increased from 63 to 87% in accordance with the level of previous experience. Common errors in species separation made by parataxonomists in relation to coleopteran families are discussed.

The use of a short-term vegetation cover to temporarily control the negative environmental effects of inactive tailings ponds is notfrequently practiced during operational mining, but could have some merit This article reports on a glasshouse trial designed to examine some of the issues associated with short-term vegetation: fast germination of a high proportion of seed, the ability of seedlings to survive in unamended substrates, and potentially toxic substrate. Five nonindigenous plant species were tested--barley (Hordeum vulgare), rye corn (Secale cereale), Italian ryegrass (Lolium multifiorum), red clover (Trifolium pratense), and lucerne (Medicago sativa)--in five different types of substrate: unamended tailings, tailings and fertilizer, tailings and greenwaste, biosolid-blend compost, and local topsoil. The nutrient and heavy metal status (As, Cu, Cd, Ni, Pb) of each substrate type was determined Plant species performance was monitored over 14 wk Substrate metal concentrations were low except for As, which was elevated in all substrate types. Plants in unamended tailings grew less vigorously than plants in tailings and compost or in topsoil. Plant performance in tailings and fertiliser was greatly suppressed following a high fertilization rate. Metal uptake in plants was highest for As (0.4-77 mg kg(-1) DW) and Cu (5.3-50.3 mg kg(-1) DW). Future field trials are necessary to authenticate findings, but barley and rye corn are promising species for a short-term tailings cover.