Abstract Detail

Mycological Section

Bruns, Thomas D. [1], Glassman, Sydney I. [2], Carver, Akiko [3], Vellinga, Else C. [3].

Post-fire Fungal Succession.

The rapidity of fungal community dynamics after fire and the relative simplicity of the post-fire community make it a highly attractive system for studying succession. Earlier work demonstrated that a set of pyrophilous fungi fruit in a predictable sequence following fire, they tend to grow fast, and they are inhibited by competition with resident soil fungi. However, most basic features of their ecology and the drivers of the succession remain unknown.
We observed mycelial presence and aerial dispersal for 1.5 years after a large, severe wild fire by analyzing a time-sequence of hyphal ingrowth bags and rainwater samples with next generation sequencing of the ITS region. In addition we collected sporocarps and isolated axenic cultures of all of the common pyrophilous fungi that fruited.
Our preliminary results show: 1) As expected, members of the Pyronemataceae and Pezizales are among the most common taxa found as spores in rainwater and mycelium in soil, but most of the common sequence-based OTUs are not represented in public sequence databases except as unidentified environmental sequences. However, at least some of these sequences do match those from our collections from these sites. 2) Pyronema omphalodes was a dominant sequence in the soil one month after the fire, and it persisted into the first spring in the soil, even though it was not observed to be a common fruiter. 3) Culture experiments and analyses of the Pyronema genomes suggest that it may target a unique carbon source in the post-fire soil. 4) Chromelosporium carneum formed ubiquitous mitotic spore mats at the site and was common in both the rainwater and mycelial samples. It may be synonymous with Plicaria endocarpoides, which was also an abundant fruiter especially in the spring of the second year. 5) Anthracobia, species make a very brief appearance in the fruiting, spore, and mycelial records, but there is not a single identified ITS sequence for it in GenBank. 6) Geopyxis, -like sequences are among the most common in the mycelial and spore records, and their sequence diversity is greater than the number of described species.
To make the system more tractable to experimental manipulation we have developed small, bucket pyrocosms. These allow us to control and monitor soil heating, soil moisture, ash content, and potentially inoculum. The first experiment with this system has just been conducted, and the design and results will be discussed.

1 - University of California Berkeley, Plant and Microbial Biology, 111 Koshland Hall, Berkeley, Ca, 94720-3102, USA
2 - University of California Berkeley, Environmental Science Policy and Management, 111 Koshland Hall, 130 Mulford Hall , Berkeley, Ca, 94720-3114, United States
3 - University of California Berkeley, Plant and Microbial Biology, 111 Koshland Hall, Plant and Microbial Biology, Berkeley, Ca, 94720-3102, United States

Keywords:
Community ecology
next generation sequencing.

Presentation Type: Oral Paper:Papers for Sections
Session: 22
Location: Salon 1/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 4:30 PM
Number: 22004
Abstract ID:980
Candidate for Awards:None