Vegetation types and climate conditions reflected by the modern phytolith assemblages in the subalpine Dalaoling Forest Reserve, central China

• Published in: Frontiers of earth science 2015-06, Vol.9 (2), p.268-275
• Main Authors: Traoré, Djakanibé Désiré, Gu, Yansheng, Liu, Humei, Shemsanga, Ceven, Ge, Jiwen
• Format: Article
• Language: English
• Subjects: Altitude; and climate change; central China; Climate change; Climatic conditions; climatic factors; Coniferophyta; Distribution patterns; dry environmental conditions; Earth and Environmental Science; Earth Sciences; ferns and fern allies; forest reserves; humidity; Mountains; phytolith records; phytoliths; Plant ecology; Poaceae; Research Article; soil; Soil surfaces; Soils; subalpine surface soil; subtropics; temperature; trees; Vegetation; vegetation types; 中国; 亚高山森林; 森林自然保护区; 植硅体; 植被分布格局; 植被类型; 气候条件; 老岭自然保护区
• ISSN: 2095-0195; 2095-0209
• DOI: 10.1007/s11707-014-0475-2

This research describes modern phytolith records and distributions from subalpine surface soils in the Dalaoling Forest Reserve, and reveals its implications for local climate conditions with respect to the altitude gradient. Well-preserved phytolith morpho-types, assemblages, and climatic indices were used to study the relationship between local vegetation and climate conditions. The phytolith classification system is mainly based on the characteristics of detailed morpho-types described for anatomical terms, which are divided into seven groups: long cells, short cells, bulliform cells, hair cells, pteridophyte type, broad-leaved type, and gymnosperm type. Phytoliths originating from the Poaceae are composed of Pooideae (rondel and trapeziform), Panicoideae (bilobate, cross, and polylobate), Chloridoideae (short/square saddle), and Bambusoideae (oblong concave saddle). Based on the altitudinal distribution of the phytolith assemblages and the indices of aridity (Iph), climate (Ic), and tree cover density (D/P), five phytolith assemblage zones have revealed the five types of climatic conditions ranging from 1,169 m to 2,005 m in turn: warm-wet, warm-xeric to warm-mesic, warm-xeric to cool-mesic, cool-xeric, and cool-mesic to cool-xeric. The Bambusoideae, Panicoideae, and Chloridoideae are the dominant vegetation at the lower-middle of the mountains, while Pooideae is mainly distributed in the higher mountains. The close relationship between phytolith assembleages and changes of altitude gradient suggest that vegetation distribution patterns and plant ecology in the Dalaoling mountains are controlled by temperature and humidity conditions. Our results highlight the importance of phytolith records as reliable ecoclimatic indicators for vegetation ecology in subtropical regions.