2021 Fiscal Year Research-status Report
Mechanisms leading to the development of alternative stable states in peatland vegetation during secondary succession after disturbance by volcanic ash
| Project/Area Number |
20K12139
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| Research Institution | Chuo University |
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Principal Investigator |
Hotes Stefan 中央大学, 理工学部, 教授 (20401185)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | vegetation / alternat. stable states / disturbance / volcanism / resilience / microbial symbionts / nutrients |
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| Outline of Annual Research Achievements |
Establishing the mesocosm experiment for testing the effects of tephra deposition on Sphagnum growth dynamics was at the center of the research activities in 2021. Growth rates of Sphagnum palustre varied among mesocosms (ca. 0.1 to ca. 30 mm in 6 months) in spite of apparently uniform conditions in terms of water availability. Only distilled water was added to compensate for evapotranspiration losses, so these differences appear to be due to initial differences in nutrient contents or nutrient use efficiency.
Nitrogen contents of leaves of Myrica gale and Hosta rectifolia collected in 2020 from the plots of the field experiment at Sarobetsu mire were determined. No statistically significant differences were observed between the experimental treatments. The field sampling and field measurements of above- and belowground organs of Myrica gale that had been scheduled in the original research plan had to be postponed due to the Covid-19 pandemic.
A database including information on grain size, thickness and main chemical components of widespread tephra layers linked to documented volcanic eruptions in Japan was prepared. Fourty-seven publications were used, providing information on 784 tephra samples.
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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
Laboratory analyses and literature studies have been carried out in line with the research plan. The field sampling in Sarobetsu Mire had to be postponed due to the Covid-19 pandemic. The pre-trials for the mesocosm experiment confirmed challenges related to the growth dynamics of the Sphagnum mosses under laboratory conditions. Abiotic environmental factors (temperature, humidity) were suitable for growth rates up to ca. 3 cm in 4 months, but several experimental units were affected by fungi colonizing the capitula of the mosses.
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| Strategy for Future Research Activity |
The plan for fiscal year 2022 includes conducting mesocosm experiments in the laboratory and field sampling at the experimental site in Sarobetsu Mire. The laboratory experiments will focus on the effect sizes of acid precipitation and deposition of fine glass grains resembling tephra on growth rates of Sphagnum mosses both individually and in combination. Because complete exclusion of fungal spores is not possible, reducing the duration of individual experiments and repeating experiments with fresh Sphagnum after thorough disinfection of the experiment chamber will be applied. In the field experiment, a sampling campaign for Sphagnum growth in different tephra treatments, the clonal structure and root nodulation of Myrica gale is planned.
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| Causes of Carryover |
The fieldwork at the experimental site in Sarobetsu Mire that had been planned for 2021 had to be postponed due to government advisories concerning travel during the Covid-19 pandemic. The fieldwork is now rescheduled for 2022.
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