講演タイトル：Strategies and resource acquisition of ectomycorrhizal fungi and wood decay fungi in forest ecosystems
(In English)
We will have a seminar by Dr. Erik Hobbie. He studies fungal functioning by using nitrogen dynamics. I hope many people come and join us. Polycom from branch office is available. I am glad if you inform me befor when you want to attend via Polycom (we will connect to HD1).
Date: 1 October 15:00～16:00
Place: Large conferece room (1st floor) in Field Science Center for Northern Biosphere (Experiment Farm)
Title: Strategies and resource acquisition of ectomycorrhizal fungi and wood decay fungi in forest ecosystems
Abstract:
We present two case studies of fungal functioning in forest ecosystems. In the first, we investigated functional differences in six taxa of decay fungi during a long-term log decomposition study (Oregon, USA) by studying elemental, isotopic, and compositional patterns in wood, cellulose, and sporocarps. Partitioning between protein and non-protein pools in mycelia prior to sporocarp formation controlled sporocarp δ15N relative to N sources. Radiocarbon measurements separated fungi into heartwood colonizers (Fomitopsis and Hericium, ~60-year-old carbon) and sapwood colonizers (Mycena (7 years), Hypholoma (11 years), and Trametes (11 years). Mycena and Hypholoma appeared to assimilate some 13C-enriched sucrose in sapwood rather than just cellulose. The six taxa varied widely in their chemical composition, as assessed by pyrolysis GC-MS; these compositional differences correlated with functional growth strategies. From these measurements, we improved the quantitative and conceptual understanding of functional differences of wood decay fungi. In the second study, we assessed how nitrogen (N) availability affected ectomycorrhizal functioning in two long-term (6-40 years) N addition experiments in Pinus sylvestris stands in Sweden. Sporocarp production declined dramatically with N fertilization but recovered slowly after fertilization stopped. Both sporocarp C/N and soil C/N increased with fertilization, implying that N uptake per unit fungal growth increased and then declined after fertilization had stopped. Fungal and soil d15N patterns across treatments identified fungal N sources, with N acquisition primarily from the S horizon for Paxillus involutus and Suillus variegatus, from the F horizon for four Cortinarius taxa and Lactarius rufus, and from the H horizon for Cortinarius traganus and Russula aeruginea. Taxa with proteolytic capabilities were particularly sensitive to N fertilization. These analyses illustrated that responses of fungal taxa across these fertilization gradients depended on the horizon of N acquisition and on N acquisition strategies.
Organized taking the opportunity that Claire de Mazancourt, I Fang Sun and Michel Loreau are in Sapporo. Everyone welcome!
11:30-12:00
Claire de Mazancourt
(French National Centre for Scientific Research, Paris)
“Invariability: measuring and understanding the effect of biodiversity on ecosystem stability”
12:00-13:00
Lunch break @Room A807
13:00-13:40
I Fang Sun
(National Dong Hwa University, Hualien; EES Hokkaido University)
“Plant reproductive decision-making and its consequence in a changing world: insights from a subtropical rain forest”
13:40-14:00
Osamu Kishida (FSC Hokkaido University)
“Growth of larval salamanders determines trophic interactions in a pond community”
14:00-14:20
Yoshio Masuda (EES Hokkaido University)
“A solution for Hutchinson’s paradox in simulated 3D oceanic
environments: coexistence of several dozens of similar phytoplankton
species at a point”
14:20-14:40
Shigeo Yachi (CER Kyoto University)
“How community-based ecosystem restoration can guarantee watershed-scale sustainability: origins and overcoming of scale mismatches in social-ecological dynamics”
14:40-15:20
Tea break @A807
15:20-15:40
Makoto Kobayashi (FSC Hokkaido University)
“Feeding behavior of detritivore determines the plant and soil response to climate warming”
15:40-16:00
Masahiro Nakamura (FSC Hokkaido University)
“Global warming effects on insect-plant interactions in tall trees of
northern forest”
16:00-16:20
Gaku Kudo (EES Hokkaido University)
“Expansion of dwarf bamboo in Japanese alpine ecosystems and its impact on biodiversity”
16:20 -17:00
Michel Loreau
(Theoretical and Experimental Ecology Station CNRS, Moulis)
“Linking biodiversity, ecosystems, and people across scales: challenges for ecology and sustainability”
17:00-17:30
Closing discussion
No registration required. We would appreciate your (while not students.) small donation for lunch and tea.
