18.14 Effects of climate change on fungi revealed by analysis of large survey data sets
Databases that store genome sequences are large because of the amount of data in each genome. Databases that store information about fungi are large because of the large number and great diversity of these organisms. One database of which you should be aware is the WWW Virtual Library: Mycology at http://mycology.cornell.edu/welcome.html; Virtual Library pages are maintained by volunteers and provide a comprehensive catalogue of internet resources of interest to all biologists who study fungi (indexed at http://mycology.cornell.edu/findex.html). Among those pages is one listing culture collections (http://mycology.cornell.edu/fcollect.html) of living and preserved fungi, and this lists a hyperlink to the World Federation of Culture Collections (http://www.wfcc.info/datacenter.html), which maintains the World Data Centre for Microorganisms (WDCM) offering searchable indexes of 556 registered culture collections in 68 countries worldwide (at the time of writing). These culture collections maintain a total of 1.4 million microbial cultures; about 600,000 of these are bacteria, 500,000 are fungi, 300,000 of them are other kinds of cellular microbe.
The United Kingdom National Culture Collection is at http://www.ukncc.co.uk/. The catalogue of UKNCC lists about 19,000 strains of fungi (including yeasts). Another important European resource is at the Centraalbureau voor Schimmelcultures (CBS), an institute of the Royal Netherlands Academy of Arts and Sciences (KNAW) which is situated in Utrecht (http://www.cbs.knaw.nl/About/). CBS maintains a collection of about 50,000 strains of microbes that includes a large proportion of the species in the fungal kingdom that have been cultivated to date. Because of the diversity of species the CBS collection it is unchallenged as a reference centre for mycological research.
The US equivalent is the American Type Culture Collection (ATCC) at http://www.atcc.org/. ATCC is the largest biological resource collection in the world with the most comprehensive range of cultures. These include over 27,000 strains of filamentous fungi and yeasts covering 1,500 genera and 7,000 species, and among that number are more than 2,000 genetic strains of Saccharomyces cerevisiae and other yeasts. The Fungal Genetics Stock Center (FGSC; at http://www.fgsc.net/) is another culture collection which was established to preserve strains that are important for the fungal genetics research community. The collection contains over 10,000 strains of Neurospora, over 2,000 Aspergillus strains and nearly 50,000 knock out mutants of Magnaporthe grisea.
Of course, all these culture collections maintain extensive data records about the cultures they keep so that the content of the corresponding databases is extremely large. Another aspect of mycological record-keeping is the maintenance of records of field observations. For example the Fungal Records Database of Britain and Ireland (FRDBI) has more than one million records (http://www.fieldmycology.net/). The FRDBI was created, and is now managed, by the British Mycological Society (http://www.britmycolsoc.org.uk/). The database contains information on names, synonyms, publications, descriptions, field observations, and over 2,500 distribution maps of British fungi, as well as pictures and identification keys. The database holds the links between all the individual elements of data, making it easier to manage and integrate the large amount of data.
Carefully recorded and regularly repeated observations of the occurrence of species in nature is essential. Individual records must be accurately identified, location of the find identified with clarity, and surrounding habitat recorded in detail. When that has been done often enough, for long enough, and over a sufficiently large geographical area field records allow species to be evaluated for occurrence in space and time, vulnerability of habitat, threats to species decline, level of protection, and taxonomic uniqueness. Species can then be ranked by number of occurrences (or rarity), number of individuals, population and habitat trends, and type and degree of threats. The data can be assembled into distribution maps (recording occurrence one species over a geographical area) and checklists (species occurrence lists that provide an inventory of species in a particular geographical region) that together contribute to conservation. Ultimately, species can be assessed as endangered, threatened, sensitive, and even extinct in the region. In particular, such records are essential to the preparation of Rarity, Endangerment, and Distribution lists (RED lists; hence, Red Data lists). Red Data lists alert conservation biologists and policy makers to issues surrounding rare fungal species and provide direction for the management and protection of the species. Decrease in fungal species diversity in northern Europe were first reported in the mid-1970s and Red Data lists are essential to awareness of such conservation issues.
Our example of the analysis of large survey data sets deals with just this sort of issue, namely the impact of climate change. In the northern temperate zone we expect to see the majority of Basidiomycota fruiting in autumn, following mycelial growth and decomposer activity in spring and summer. Temperature and rainfall are the two main factors affecting productivity. In a 21-year survey of a forest plot in Switzerland, appearance of fruit bodies was correlated with July and August temperatures, an increase of 1°C resulting in a delay of fruiting by saprotrophs of about 7 d. In contrast, fruit body productivity was correlated with rainfall in the period June to October (Straatsma, Ayer & Egli, 2001).
Climate change has been, and remains, a major concern. Several studies have shown climate-associated changes in periodic life cycle events in plants, insects and birds, and this has recently been demonstrated to be the case for fungi. We have already described (Section 13.17) that changes in the seasonal pattern of fungal fruit body formation in the UK have been detected from field records of fruit body finds made over the last 60 years (Gange et al., 2007). This study analysed a large data set of fruiting records of 200 species of decomposer Basidiomycota in Wiltshire, U.K., recorded during 1950 to 2005.
Statistical analysis of this data set showed that the mushroom fruiting season has been extended since the 1970s. On average the date at which the first fruiting bodies appeared is now significantly earlier (the average advancement was 7.9 days per decade). Similarly, the last date on which fruiting bodies were seen is significantly later in 2005 than it was in 1950 (average delay was 7.2 d per decade). In the 1950s the average fruiting period of the 315 species in the data set was 33.2 days, but this has more than doubled to 74.8 days in the first decade of the 21st century.
As well as changes to autumn fruiting patterns, significant numbers of species that previously only fruited in autumn now also fruit in spring; the response depending on habitat type. Since mycelia must be active in uptake of water, nutrients and energy sources before fruit bodies can be produced this suggests that these fungi may now be more active in winter and spring than they were in the past.
Climate changes in Wiltshire were also analysed thanks to well maintained local weather records. There was a significant relationship between early fruiting and summer temperature and rainfall. Local July and August temperatures have significantly increased, while rainfall has decreased over the 56 years of the survey (Gange et al., 2007). Clearly, climate change has resulted in changes in periodic behaviour in fungi just as in other organisms and this study shows it’s happening right in your own back yard.
Updated December 17, 2016