In a previous post, Libby Robin wrote about aseasonality and the seasonal exceptionalism of Australia and elsewhere. The paradox of turning leaves and blossom jostling on the one branch are a striking reminder that our seasons are awry.
As few of us in the western world are dependent on acute seasonal observations of fruiting, flowering, migrations and so forth for survival, we’re less attuned to the nuances of seasonal change. Could it be that we’re too busy aseasonally tweeting to notice…?
I follow fungi across the globe. My movements between hemispheres coincide with autumn in both. This is when most fungi invest their energy into reproducing – into the formation of the familiar mushrooms and other fruitbodies that burst through the earth in a riot of amazing forms and colours. It means I get a double dose of fungi. But what, or when is autumn? And how have my trans-global movements contributed to the confused fungal fruiting and the instability of our concepts of seasons?
Libby and other astute observers notice the changed timing of events within the plant and animal kingdoms – the so-called producers and consumers. Less often considered are the recyclers or decomposers – including fungi – and how they too may be affected by climate change.
While the majority of fungi fruit in autumn, some adopt a different strategy, appearing in spring. Morels are among the more familiar spring-fruiters.
However, last spring, popping up among the morels, were mushrooms I’d only previously encountered in autumn. Had the wet and mild winter influenced their aseasonal fruiting or was it a sign of something more worrying? Could their spring presence indicate climate change impacts on a larger scale? Just what is going on down under Downunder?
The past decades have seen a surge of studies documenting phenological responses of flora and fauna to climate change. But few include fungi. Most of this research has been in the middle and higher latitudes. One of the few long-term fungal research projects in the UK revealed fungal fruiting periods are extended in association with increased rainfall and temperature, with many species now fruiting twice a year. While mycophagists may welcome this news, the effects of mycelial activity and greater rates of decay in ecosystems in altering the timing of ecosystem processes is little known. How might climate change affect symbiotic associations between fungi and plants (mycorrhizas) and longer term ecosystem dynamics? Other European studies showed correlations between climatic conditions in one year and the occurrence of fungal fruiting in the following, suggesting that mycelia are influenced by climatic conditions over longer time periods before fruiting. What is also known is that mycorrhizal fungi have a major influence on the global carbon cycle.
Travelling scientists and others partial to coffee may not be too happy to hear about the fungus known as Hemileia vastatrix or coffee rust, which is enjoying climate change-induced weather extremes and consequently devastating central Americas coffee plantations. It has also managed to spread to higher altitudes thanks to warmer weather. Fungi colonise an enormous array of substrates including those manufactured by humans. Some even have a particular taste for airline fuel. The future, especially for travelling scientists, may be more fungal than we think….
/Alison Pouliot