Do flower litters contritubte to resource input into soil ecosystems?

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02999
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: Akita Prefectural University
• Principal Investigator: Hoshizaki Kazuhiko 秋田県立大学, 生物資源科学部, 教授 (30322655)
• Co-Investigator(Kenkyū-buntansha): 野口 麻穂子 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (00455263) ; 井田 秀行 信州大学, 学術研究院教育学系, 教授 (70324217)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: リターフォール / 窒素 / リン / 開花

Outline of Final Research Achievements

Using major tree species in temperate forests in Japan, we found that nitrogen and phosphorous content was highest for pollen, followed by flower litter. Those for the leaf litter were the lowest. The same pattern applied to decomposability based on C/N. Based on long-term monitoring of litter trapping during 1991-2015, the contribution of flower litters and that of pollens were negligible in terms of dry weight, whereas those increased in terms of nitrogen and phosphorous inputs, which accounted for up to 8.4% (CV 1.29) for nitrogen and 27% (CV 1.10) for phosphorous. Based on a litter bag experiment in which flower or leaf litters were packed separately, we found that the decomposition of flower litters was, for all species examined, much higher than were leaf litters. These results coincided with that the first findings that flower litters contain much nitrogen and phosphorous with higher C/N.

Free Research Field

森林生態学

Academic Significance and Societal Importance of the Research Achievements

森林樹木の開花量の年変動は世界中の森林で広く見られる現象で、その発生メカニズムや進化生態学的意義、動物個体群への波及反応などの関連分野に影響を与えてきたが、物質循環研究との接点はこれまでほとんど見られなかった。本課題では、開花の年変動が土壌生態系への窒素供給に季節的、年間のパルスを形成していることを発見した。これらの知見は、今後の学際的な研究の糸口となりうるほか、開花にともなう花粉飛散が林地の肥料となりうる可能性を示唆しており、林業など応用的な観点でも意義がある。