314회 캐나다 북부침엽수림 내에서 소나무, 송화가루와 균류의 상호작용

314회

연사 : 이 은 주 , 서울대학교 자연과학대학 생명과학부

제목:  캐나다 북부침엽수림 내에서 소나무, 송화가루와 균류의 상호작용

Abstract

The boreal forest, or Taiga, is a broad, circumpolar mixture of cool coniferous and deciduous tree species which cover 14.7 million km2, or 11%, of the earth's terrestrial surface. Importance of pollen rain as nutrient source was investigated in the boreal forest ecosystem of west-central Manitoba. Total annual pollen deposition ranged between 16-25 kg/ha at the three sites, corresponding to nutrient inputs of 0.34-0.49 kg N/ha, 0.04-0.07 kg/ha, and 0.11-0.20 kg K/ha. The combination of highly episodic, early summer deposition and very rapid nutrient turnover suggest that pollen may play an important role in supplying nutrients and promoting decomposition in the forest litter layer. The spatial and temporal patterns of pollen infestation were investigated along a gradient of boreal microhabitats. This study shows that chytrids have roles in initial colonization and degradation of resistant pollen substrate in boreal forests and making it less refractory for other organisms. Significant differences in total pollen infestation in diverse boreal forest sites were found. The results indicated that infestation levels vary with types of decaying litter types. It is concluded that competition for nitrogen and other nutrients may occur in substrates of high C/N ratio such as in the boreal forest and chytrids adapt more favourably in dry, acidic sites with needle litters which are more hostile conditions to other decomposers. Possible linkages between pollen, chytrids, ectomycorrhizal fungi and forest tree nutrient acquisition are discussed.