Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Report submitted to the New Zealand Department of Conservation

Fungi and their associated Mycophagous beetle biodiversity on subantarctic Campbell Island

Submitted to the New Zealand Department of Conservation by Rich Leschen, New Zealand Arthropod Collection, Landcare Research, Private Bag 92170, Auckland, New Zealand

The biodiversity of fungi, slime molds, and their associated Coleopterans, unlike the mosses, liverworts, lichens, and insects in general, has been little explored for the more southerly New Zealand subantarctic islands -- Campbell Island and the Auckland Islands group (50º to 52º S). The expedition, in March 2000, consisted of nine scientists who represent expertise in the organismal groups of rust, smut, and hymenomycete Basidiomycetes, and their associated higher plant and bryophyte substrates, the inoperculate and operculate Ascomycetes, the endomycorrhizal Zygomycetes, the aquatic and terrestrial Hyphomycetes -- all Deuteromycetes, the Myxomycete (plasmodial), Acrasiomycete (dictyostelid), and Protosteliomycete (protostelid) slime molds, the zoosporic Chytridiomycetes and Oomycetes, bryophytes and lichens and their coleopteran (beetle) associated insects. Prior to this visit, little had been reported - at least for the fungi. Over a 145 year period (1840-1985), only 27 species of fungi had been reported from Campbell Island and 28 species from the Auckland Islands. During the three weeks of our visit, over 3000 collections were made representing all groups investigated.

These new collections constitute a very major addition to the little known subantarctic fungi, slime molds, beetles, bryophytes and lichens. First estimates suggest: 55 species of Agaricales in 330 collections (Gary Laursen); 75 species of woody substrate and wood inhabiting Aphyllophorales in 400 collections, with the added advantage of over 60 cultures of different fungi, often in multiple cultures (Hal Burdsall); 28 species of rusts, 3 species of smut fungi in 100 collections, and 44 collections of jelly fungi, all recorded within the Teliomycetes (Eric McKenzie and Hal Burdsall), and all in the Basidiomycetes; 75 species of inoperculate and operculate Ascomycetes in ca. 275 collections, with 40 cultures established for fungi in two large groups, the Rhytismataceae and Helotiales (Peter Johnston and Gary Laursen); roots from 102 plants representing 88 (60%) of the 146 vascular plant species (143 indigenous, 3 endemic) from Campbell Island's vascular flora were preserved in gluteraldehyde, formalin-acetic acid-alcohol, and ethanol for sectioning and describing mycorrhizal associations (Gary Laursen and Rod Seppelt); several collections of woody substrates were made and set up in incubation chambers for Hyphomycete, Deuteromycetes, extraction and enumeration (Eric McKenzie); 20 species of slime molds in 85 collections of Myxomycetes (Steve Stephenson); species of dictyostelids and protostelids are yet to be demonstrated through microcosm growth chamber culturing from the numerous collections of bark, aerial, and leaf litter types (Steve Stephenson); 81 collections of beetles (Coleoptera) were made that represent ca. 1500 specimens representing about 80% of the known fauna (Rich Leschen); 575 collections of mosses and liverworts (Bryophyta) were made as many are particularly important as substrates for fruiting mycota (Rod Seppelt).

The field work phase of our project is a prelude to our separate laboratory studies to begin the cultural, microscopic, descriptive and final identification phases of the work. Insufficient time was spent in the Auckland Islands to proffer any sensible comparison of the mycoflora and habitats, though some interesting comparisons can be made to our previous studies on Macquarie Island and published records from other Subantarctic Islands and New Zealand. In comparison with Macquarie Island, Campbell Island lacks true fellfield. The vegetation of upland areas on the higher peaks is more comparable to plateau wet herbfield on Macquarie Island. Tarns and lakes are also conspicuously absent on Campbell Island. However, Macquarie Island lacks woody vegetation and the bryophyte and lichen flora on woody species, particularly Dracophyllum, is particularly well developed on Campbell Island. All collections have yet to be fullyexamined, are almost certain to yield new species, and will certainly extend the geographic range of many known species of fungi, their insect and bryophyte associates.

The 22 species of Basidiomycetes listed for New Zealand's subantarctic islands included only 8 Hymenomycetes, and of these, 3 are Agaricales and 5 Aphyllophorales. Approximately 52 new agarics and ca 70 wood inhabiting resupinate and/or bracket fungi are added to the mycota. Some will merely extend geographical range limits of already known species, but others are suspected to be new species. Again, as was found on Macquarie Island (54ºS) some 120 miles SE of Campbell Island, no ectomycorrhizal fungus species were found. All appear to be saprobic decomposers of the readily available substrates produced by the 148 vascular plants. Most are probably not indigenous to the two island groups as they are saprophytic generalists and most likely brought in by wind or by migrating birds. Expected, but missing, were species of Clitocybe in the Tricholomataceae, while other members of this family were in great abundance (Omphalia, Favolaschia, Hydropus, Mycena, Tephrocybe, Richenella, and others). Omphalia luteovitellinia, while not found on Macquarie Island or in the Auckland Islands, was common, more so even than has been reported for high latitudes in the northern hemisphere. Present in relative abundance were species of Hypholoma (Stophariaceae) and two species of Agaricus (Agaricaceae), one dominant under Dracophyllum longisporum and the other under D. scoparium.

Rust and smut fungi are near obligate plant pathogens. Approximately 250 species of rust fungi are known from New Zealand, or about 1 species to every 16 native and naturalized vascular plant species. About 18 species of rust fungi are now known to occur on Campbell Island. Thirteen of these are newly recorded as a result of the expedition, and now have a broad extension to their geographic range. Four previously unrecorded rust fungi were found in the Auckland Islands, giving 10 species known for that island group. Campbell Island thus has a ratio of 1 rust per 13 higher plants and the Auckland lslands a ratio of 1 to 23. A new species of rust was found on Dracophyllum longifolium on both Campbell and Auckland Islands; no rust fungus is known on Dracophyllum from mainland New Zealand. The fern, Polystichum vestitum, was found to be a new host for a rust fungus as was Hebe benthamii. Several introduced grasses (Arrhenantherum, Festuca, Holcus, and Poa) were found to be infected by crown rust. A rust on Oreobolus pectinatus, with an unusual distribution of Papua New Guinea and Campbell Island, was discovered in the Auckland Islands. The 1975 Campbell Island specimen was a very small collection which has previously not allowed a full taxonomic comparison to be made with the New Guinea material.

Only 3 smut fungi were found; head smuts on Uncinia on Campbell Island and on Oreobolus in the Auckland Islands (Auckland and Enderby), and a leaf smut on introduced Poa on Campbell Island. The Oreobolus smut was known previously only from Arthur's Pass in Mid Canterbury, south island of New Zealand.

The non-lichenized Ascomycetes are the most diverse group of fungi in New Zealand, almost half of the 6,500 species reported for the country belong in this single group. About 16 species had previously been reported for Campbell Island. Preliminary results from our expedition suggest that the 200 collections made at Campbell Island represent at least 75 additional species records, although confirmation of these numbers await critical examination of the collections. The geographic relationships of the species found on Campbell Island appear to be with mainland New Zealand. The majority of the Campbell Island species are found on similar hosts and substrates in other parts of New Zealand. As throughout New Zealand, operculate discomycetes are rare. Members of the Xylariaceae, especially in the genera Hypoxylon and Biscogniauxia, were frequently found on the fallen wood of Dracophyllum longifolium and Myrsine divaricata, and appear to form a significant component of the wood rotting biota. Interestingly, Xylaria, a genus of Xylariaceae common in the forests of mainland New Zealand, was not found on Campbell Island. A few Xylaria collections were made on the more northerly Auckland Islands. Damage by fungal feeding invertebrates was not observed on the xylariaceous fruiting bodies on Campbell Island, although such damage is common in the mainland forests and was also present on the Auckland Islands. Feeding damage by rats on fruiting bodies of a Biscogniauxia species commonly found on fallen Dracophyllum wood was frequent in all parts of Campbell Island. The other species of Xylariaceae were not obviously targeted by rats. Several of the species of fungi found are probably undescribed. These include two fungi associated with leaf spots on Myrsine divaricata and a pathogen on the fronds of Polystichum vestitum. As on mainland New Zealand, the fallen leaves of Dracophyllum were a rich substrate for Rhytismataceae in the genera Lophodermium and Hypoderma. A more surprising find was of two species of wood-inhabiting Rhytismataceae in the genus Colpoma. Both are probably undescribed, and represent a genus found extremely rarely on mainland New Zealand. More than 40 of the collections of Rhytismataceae and Helotiales were obtained in pure culture. Attempts will be made to obtain all Xylariaceae collected in culture. The cultures will be stored under liquid nitrogen and will be available for future molecular and other studies.

Hyphomycete fungi were collected mainly on dead wood and fallen leaves of Dracophyllum and southern rata (Metrosideros umbellata), two substrates which have not been previously examined for such fungi in the subantarctic. Additional species of hyphomycetes are currently being isolated from samples of various types of organic debris. Prior to the present study, only a single slime mold (a myxomycete, Trichia favoginea) was known from either of the two island groups studied. The collecting effort carried out during the field work reported herein yielded approximately 50 specimens of myxomycetes from Campbell Island and at least 35 specimens from the Auckland Islands. Preliminary examination of this material suggests that at least 20 different species are represented among these 85 specimens. The majority of these are new records for the subantarctic. Samples of organic debris (e.g., bark from living trees, leaf litter, aerial litter, etc.) were collected from a number of study sites on Campbell Island and from two different study sites in the Auckland Island group (Auckland and Enderby Islands). An effort is being made to isolate additional species ofmyxomycetes from these samples. A number of the samples will be examined, using standard laboratory isolation techniques for the groups of organisms involved, to determine the presence of dictyostelid and protostelid slime molds. It is anticipated that specimens from both groups will be "cultured" from these samples, although these data will not be available immediately. Few previous studies of either dictyostelids or protostelids have been carried out in the subantarctic. Results obtained will be analysed with comparable data already available for the northern hemisphere at similar latitudes (50º to 58º).

The bryophyte flora of both Campbell Island and the Auckland Islands has been previously studied and have provided a basis for identification of mosses and hepatics. The best known are the mosses of both island groups (Campbell Island -- 119 species; Auckland Islands--145 species). Some previous collections of hepatics and lichens have been made but no up to date compilations are available. Affinities of the bryophyte and lichen floras are more strongly aligned with New Zealand than Australia, but there is also a small subantarctic element. As a result of the present collections at least one moss (Chrysoblastella chilensis) and several hepatics will be added to the known flora. The lichen collections were not comprehensive but will supplement previous collections, particularly those made by Landcare staff from Lincoln.

Eighty-one collections of beetles were made on Campbell Island (26 were made on Auckland and Enderby Islands) and represent over 1500 specimens and 80% of the known fauna of Coleoptera known for Campbell Island. Most groups were collected, though Curculionidae were not well represented due to the lack of flowering vegetation. New species of Staphylinidae were discovered, including a new species of the endemic Campbell Island genus Pselaphotheseus (Pselaphinae). While trophic studies based on gut analysis, will be done in the future, there are only two strictly mycophagous Coleoptera known to Campbell Island in the families Corylophidae (Holopsis oblongus) and Latridiidae (Melanophthalma globipennis). It is expected that many of the detritus associated staphylinoids and the single wood feeding tenebrionid may include microfungi in their saprophagous diets. While the Campbell Island distribution of phytophagous beetles are host limited, other Coleoptera are distributed over the entire island, while still yet another major faunal component is limited to the intertidal areas. The Campbell Island Coleoptera are composed of a largely south temperate assemblage of taxa that have relatives distributed throughout New Zealand and others with broader distributions in Chile and on other subantarctic islands. One intertidal species endemic to Campbell Island, Baeostethus chiltoni, has relatives in the northern Pacific rim and phylogenetic analysis of certain groups, especially Staphylinidae will help to elucidate biogeographic patterns.