Mutualistic networks among dwarf shrubs of the family Ericaceae, pollinators, and seed dispersers in an alpine region

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K07849
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Forest science
• Research Institution: Nagano University
• Principal Investigator: Takahashi Kazuaki 長野大学, 環境ツーリズム学部, 教授 (10401184)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: ツキノワグマ / ガンコウラン / 酸素安定同位体 / 地球温暖化 / ハシブトガラス / オオマルマルハナバチ / クロマメノキ / シラタマノキ

Outline of Final Research Achievements

Bombus hypocrita hypocrite was identified as a major pollinator of Vaccinium uliginosum var. japonicum, Gaultheria pyroloides, and V. vitis-idaea. In these three species, the fruiting rates tended to be higher with cross-pollinators than with self-pollinators. Japanese black bears (Ursus thibetanus japonicus) and Jungle Crow (Corvus macrorhynchos) were identified as major seed dispersers of Empetrum nigrum var. japonicum, with high frequency of fruit use. We identified Turdus eunomus as a seed disperser of V. uliginosum var. japonicum, and black bears and Vulpes vulpes japonica as a seed disperser of G. pyroloides, although they used the fruits less frequently. Analysis of stable oxygen isotope ratio in the seeds indicated that black bears contribute to seed dispersal of E. nigrum var. japonicum to high altitudes. The black bear may become an important seed disperser that could save E. nigrum var. japonicum from the effects of global warming.

Free Research Field

森林生態学

Academic Significance and Societal Importance of the Research Achievements

本研究は、地球温暖化の影響が最も懸念されるスポットの一つである高山帯に着目し、植物の繁殖（花粉媒介と種子散布）にとって重要な作用系であるにもかかわらず、研究が遅れていた“生物が相互に利用しあう”「相利共生」と気温上昇との関係の全貌解明を試みた。送粉系と種子散布系をめぐる動植物の「相利共生ネットワーク」と「気温上昇の影響」の基本的なパターンを解明し、地球温暖化が「植物－花粉媒介者－種子散布者」相利共生ネットワークに与える影響を推測するで、地球温暖化が高山帯の生物に及ぼす影響に関する研究の基礎を構築することに貢献できる。