日本本州北部白神山地圆齿水青冈林(Fagus crenata)表土花粉分析及水青冈属花粉的代表性

POLLEN ANALYSIS OF MOSS POLSTERS FROM BEECH FORESTS (FAGUS CRENATA) IN HIRAKAMIDAKE, NORTHERN HONSHU, JAPAN WITH REMARKS ON THE REPRESENTATION OF FAGUS POLLEN

为揭示和探讨水青冈表土花粉与现生植被的关系及其花粉代表性,我们对日本本州北部白神岳圆齿水青冈林中苔藓表土花粉进行了分析,结合前人研究资料,结果表明Fagus花粉可有效指示青冈林森林植被:在水青冈优势林中Fagus花粉百分含量达35%—40%以上;偏离水青冈林或无水青冈林分布时,含量低于5%—10%;介于两者之间为含有水青冈的混交林。这一结果与我国众多学者报道的表土花粉研究显示Fagus花粉的低代表性不相一致,其主要原因可能与国内取样点松属(Pinus)花粉的突出含量及林地较高的植物多样性紧密相关,从而干扰"遮掩"了水青冈花粉具有合适代表性这一特点。

To clarity the relationship between Fagus pollen percentages and its vegetation coverage, we conduct a pollen analysis of moss polsters from beech forests (Fagus crenata) in Hirakamidake, northern Honshu, Japan. A total of seven samples were selected for pollen analysis. It shows that Fagus pollen is well represented in samples from beech-dominant forests, most of which have percentages more than 40%. Integrated with published data, our results show that Fagus usually accounts for more than 35%—40% in Fagus-dominant forests, 35%—40% to 5%—10% in Fagus-mixed forests and lower than 5%—10% in Fagus-absent vegetation or outside of beech forests. The reported under-representation of Fagus pollen in China could generally result from the rich plant diversity, and especially abundant Pinus in samples which is notoriously over-represented, thus considerably overshading the representation of Fagus in surface pollen.