浙江青浜岛现代植物群落和表土植硅体研究及环境意义

PHYTOLITH RECORDS OF MODERN PLANT COMMUNITIES AND SURFACE SOILS ON THE QINGBANG ISLAND,ZHEJIANG PROVINCE,EAST CHINA AND ITS ENVIRONMENTAL SIGNIFICANCES

在植物分类基础上全面调查了浙江舟山青浜岛分布的植物群落类型,获得8个群丛类型,对青浜岛25种现代植物植硅体进行提取,共鉴定出17种形态类型。帽型、齿型、哑铃型、鞍型和扇型主要见于禾本科植物;蕨类主要产波状棒型和三棱柱型;木本主要产纺锤型和多边形板状型,这表明不同分类位置的植物产生不同的植硅体形态及组合。对横跨整个青浜岛东南—西北坡向的8个群丛样方进行表土植硅体提取分析,共获得14种植硅体形态类型,研究结果显示表土植硅体贡献主要来自禾本科、蕨类、阔叶类和裸子类植物。随着岛屿山体海拔的增加(海拔20—90m),示冷型和示干旱型植硅体增加,青浜岛局部生境(自东南向西北翻过山顶)气候变化表现为温暖湿润—温凉偏干—温暖湿润。表土植硅体组合灵敏地响应了海拔改变而引起的局地植被和环境的变化,是重建第四纪环境变化的可靠代用指标。

Based on phytocoenosis and a complete vegetation investigation on modern plant communities on the Qingbang Island, Zhejiang Province, East China, 8 plant associations were identified. Phytoliths from 25 modern plants of the Qingbang Island were extracted and classified into 17 types. Rondel, trapeziform sinuate, bilobates and cuneiform bulliform cells were produced in Poaceae. Fern phytoliths contribute prism sinuate and elongate undulating. Phytolith morphotypes from the woody plants are mainly platelets polygon and vascular tissues. Based on phytolith extraction from 8 surface soils from southeast to northwest slopes across the Qingbang Island, 14 phytolith morphotypes were identified. The majority of phytoliths described in the surface soils are from Gramineae, fern, coniferous, and broad-leaved trees. The amounts of cold types （elongates） and dry types （short saddles） rise with the increase of ele- vation, ranging from 20 m to 90 m. Phytolith assemblage zones also reflect local climate conditions on the Qingbang Island as （from southeast to northwest） ： warm-wet, cool-dry to warm-wet. Phytolith assemblages from surface soils have sensitively responded to the local vegetation and environment changes that are caused by the elevation change. Our research demonstrates that the phytolith records are reliable proxies of Quaternary environment conditions.