Mushroom fruiting and climate change

Abstract

Many species of fungi produce ephemeral autumnal fruiting bodies to spread and multiply. Despite their attraction for mushroom pickers and their economic importance, little is known about the phenology of fruiting bodies. Using Ϸ34,500 dated herbarium records we analyzed changes in the autumnal fruiting date of mushrooms in Norway over the period 1940 -2006. We show that the time of fruiting has changed considerably over this time period, with an average delay in fruiting since 1980 of 12.9 days. The changes differ strongly between species and groups of species. Early-fruiting species have experienced a stronger delay than late fruiters, resulting in a more compressed fruiting season. There is also a geographic trend of earlier fruiting in the northern and more continental parts of Norway than in more southern and oceanic parts. Incorporating monthly precipitation and temperature variables into the analyses provides indications that increasing temperatures during autumn and winter months bring about significant delay of fruiting both in the same year and in the subsequent year. The recent changes in autumnal mushroom phenology coincide with the extension of the growing season caused by global climate change and are likely to continue under the current climate change scenario.phenology ͉ global warming ͉ herbarium data ͉ fungi ͉ agarics P henological changes are among the most sensitive ecological responses to changing climate (1-3). The observed extension of the average annual growing season in Europe by nearly 11 days since the early 1960s (4) has been followed by rapid and recent changes in plant flowering time (5-8) and earlier spring migration in several bird species (9). In a recent study from the United Kingdom, it was reported for a set of mushroom species that fruiting on average started earlier and ended later in the season in recent years than 20 years ago, i.e., that the fruiting period has been greatly extended (10). These changes were linked to increased temperature and rainfall in August and October, respectively (10).Most fungi produce ephemeral fruiting bodies that can be observed only for a few days each year, which makes phenological data difficult and time-consuming to obtain. However, because of the short endurance of the fruiting bodies, collection time is a good estimate of fruiting time. A potential source of phenological information for this group of organisms is therefore herbarium collections, which, although sampled in a nonsystematic manner, share properties with random sampling processes. Herbarium data can enable us to understand and predict climate-induced ecological changes in the future by understanding how climate has affected ecological processes in the past. Several studies have already documented that herbarium collections may represent a valuable source of long-term and reliable phenological information (e.g., refs. 7 and 8).Our study of temporal trends in fruiting phenology is based on Ͼ34,500 herbarium records collected in Norway during the period 1940-2006 and representin...

Warming-induced shift in European mushroom fruiting phenology

“…In the United Kingdom, the overall autumnal fruiting season has extended in both directions (i.e., earlier onset and later finish), for mycorrhizal and saprotrophic species (6,7,12). In Norway, the mean autumn fruiting date is now later for both mycorrhizal and saprotrophic fungi (13), with similar observations in Switzerland, based on a long-term survey of forest plots (5). In both Norway and the United Kingdom, the recent changes in fruiting are dependent on fungus life-history strategy, with differences between early-fruiting species and latefruiting species (6,13).…”

“…In Norway, the mean autumn fruiting date is now later for both mycorrhizal and saprotrophic fungi (13), with similar observations in Switzerland, based on a long-term survey of forest plots (5). In both Norway and the United Kingdom, the recent changes in fruiting are dependent on fungus life-history strategy, with differences between early-fruiting species and latefruiting species (6,13). Furthermore, since 1975, many species of fleshy fungi that previously fruited only in autumn in the United Kingdom now also fruit in spring (6,12), and in both Norway and the United Kingdom spring fruiting now occurs earlier than it did in the 1960s (14).…”

“…Climate-induced changes in phenological patterns have been documented in many plants and animals (9-11) and recently in fungal fruiting (5)(6)(7)(12)(13)(14). In the United Kingdom, the overall autumnal fruiting season has extended in both directions (i.e., earlier onset and later finish), for mycorrhizal and saprotrophic species (6,7,12).…”

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