Springbrook Fungi

Fungi — the most colourful, diverse, and ecologically fundamental Kingdom on Earth

Surveying and identifying fungi are important aspects of Springbrook Rescue. They can give clues as to whether restoration is proceeding naturally or needs our help.

Fungi are essential for the health and survival of almost all ecosystems. In fact, plants would not have been able to colonise the earth half a billion years ago without a partnership with fungi. They are a biological Kingdom in their own right, separate from animals, microorganisms, and plants, but are closer to animals than any other group of living organisms. There are potentially 1.5 million or more species of fungi on earth but only 6–7 per cent are formally known or described. It is thought that the total number of fungi in Australia may be 50,000-250,000 species of which only 11,846 are described (including 3,495 lichens) and most are unique to this country.

They control the fundamental carbon, water and nutrient fluxes that support life on earth, which in turn determine the diversity of species, their interactions with each other and the environment, and the myriad feedback loops amongst them that are so critical to long-term ecosystem resilience.

Fungi have many functions within ecosystems — as decomposers, symbiotic partners, nutrient cyclers, food sources, habitat creators and soil conditioners. Given their great diversity, ecological significance and specialised life styles, long-term fruiting body surveys of ectomycorrhizal fungi in particular constitute an extremely valuable, efficient indicator of ecosystem health and successional trends in ecological restoration projects.

Fungi are heterotrophic and thus must gain their carbon nutrition from external organic sources. At a broad trophic level, fungi are either
(a) free-living, gaining their essential carbon supplies by decomposing dead and decaying organic matter — the saprotrophic fungi or saprobes; or
(b) symbiotic, deriving their carbon supplies through intimate associations with other living species. These associations may be mutualistic (both benefiting), commensalistic (only one benefiting, the other partner unaffected, or parasitic/pathogenic (one benefiting, the host harmed.

Saprobes
Saprotrophic fungi or saprobes are found in soil, litter or wood, breaking down the cellulose, lignin and organic matter for their carbon supplies. Most of this carbon is returned to the atmosphere as CO2 through fungal aerobic respiration. They are vital to nutrient cycling and the integrity of trophic webs. Examples of litter decomposers include Marasmius and Mycena species. A few of the many wood decay fungi at Springbrook include species of Ganoderma, Piptoporus, Fomitopsis, Serpula. Because saprobes can have strong preferences for the type, age, and size of their host, they can be good indicators of successional dynamics. Saprotrophic fungi are also responsible for creating nesting hollows for so many of our forest fauna.

Mutualistic symbionts
Mutualistic symbionts include the mycorrhizal fungi that colonise plant roots, and fungal endophytes that live entirely within plant tissues.

Mycorrhiza
Mycorrhizal fungi can be vesicular arbuscular mycorrhizas (VAM), ectomycorrhizas (ECM), ericoid mycorrhizas or orchid mycorrhizas.

The arbuscular mycorrhizas (VAM) are members of the Glomeromycota phylum. Though not species rich (only 230 described species) they are the most ancient, abundant and widespread of all fungi. They are nearly all obligate symbionts and provide vital phosphorus and nitrogen supplies to more than 80% of land plants which, in return, provide the fungi with sugars manufactured by photosynthesis. Their spores are large and readily detectable in soil extracts with a low-powered dissecting microscope.

Most ectomycorrhizal (ECM) fungi are macrofungi with readily visible fruit-bodies such as ‘mushrooms’ above ground, and truffles below. Fruit-body production is highly seasonal, irregular and patchy. Some fungi do not fruit for years; others are too cryptic to be noticed easily. They are members of either the Ascomycota (clubs, cups, flasks, jellies) and Basidiomycota (agarics, boletes, chantarelles corals, earthstars, polypores, puffballs, stinkhorns) and associate particularly with roots of the Casuarinaceae, Fabaceae (Mimosoideae, Papiloinoideae), Meliaceae, Myrtaceae, Nothofagaceae, Nyctaginaceae, Phyllanthaceae and Rhamnaceae plant families.

Erecoid mycorrhizas, mostly from the Ascomycota, are indispensible partners of plants in the Ericales order. These generally occur in stressful environments on ancient, highly weathered, nutrient-poor soils. At least 13 members of the Ericaceae occur at Springbrook in forests and heaths on depauperate rhyolite-derived soils.

Orchid mycorrhizas, mostly from the Basidiomycota, are likewise critically important for germination of miniscule orchid seeds that have virtually no energy reserves of their own.

Endophytes
Fungal endophytes, mainly members of the Ascomycetes, live entirely within root, stem and/or leaf tissues of all land plants. They have profound effects on plant ecology, survival, fitness and evolution. They improve biotic and abiotic stress tolerance, nutrient acquisition and productivity. These mutualistic symbiotic associations appear to be as ancient as those with mycorrhizas and as significant in facilitating the evolution of terrestrial floras.

Commensalist symbionts
Commensalism is very common in rainforests with good examples provided by epifoliar fungi (on leaf surfaces), mostly within the Ascomycota. The fungi spend their entire life cycle live on the surface of living plant leaves. They do not harm their host because plants can generally photo-compensate for light lost due to the epiphyll cover. Lichens can be considered an example of commensalism between a fungus and photosynthetic partner, either a green alga or cyanobacterium.

Parasitic/Pathogenic symbionts
All Tremella species parasitise other wood-rotting fungi (saprophytes) in both Ascomycota and Basidiomycota phyla. Tremella mesenterica (a gelly fungus) parasitises many members of the Peniophora genus. Beauvaria species (asexually reproducing forms of Cordyceps) parasitise a range of arthropod species. The microscopic spores, when in contact with the insect host, germinate and penetrate the cuticle killing the insect within days. Later a white mould emerges on the outside, producing more spores to attack more insects.

Tremella mesenterica Photo: © Aila Keto

Dacrymyces s.l. Photo: © Aila Keto

Beauvaria bassiana parasitises arthropods Photo: © Aila Keto

Ecosystem engineers
Fungal hyphae also help bind soil particles into water-stable aggregates that are separated by pore spaces responsible for the soils water holding-capacity, infiltration and drainage properties.

ASCOMYCOTA

Cups

Cookeina tricholoma (Sarcoscyphaceae) in the Pezizales Order, a tropical saprobe found on dead wood in rainforests at high altitudes at Springbrook

BASIDIOMYCOTA

Agarics

Marasmius elegans (Marasmiaceae) a litter saprobe.

Cyptotrama asprata (Marasmiaceae) a saprobe on decaying woood in tropical and subtropical forests

Agaricus bitorquis (Agaricaceae)

Gymnopilus junonius (Cotinariaceae)

Chantarelles

Cantharellus ochraceoravus (Cantharellaceae) a mycorrhizal fungus

Polypores

Gloeoporus phlebophorus  (Meruliaceae), a saprobe on wood, mainly fallen tree trunks or branches causing a form of white rot. A temperate species in southern Australia, commonly on Beech species.

Microporus xanthopus Yellow-footed Tinypore (Polyporaceae) a saprobe on rotting wood

The funnel-shaped caps are often wavy and can hold water. The undersurface is white with tiny pores.

Leathers

Stereum sp. (Steareaceae)

Stereum sp. (Steareaceae)

Dacrymyces s.l. (Dacrymycetaceae)
It looks very much like D. chrysospermus but this species is symmetrically rather than irregularly lobed.

Tremella globispora (Tremellaceae)

The name Tremella is from the Latin tremere “to tremble” because of its jelly-like nature.

Puffballs

Geastrum sp. An Earth Star (Geastraceae)

Cyathus stercoreus (Nidulariaceae), a saprobe on dung or dung enriched soils.

SLIME MOULDS