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浙南岛屿潮间带蟹类的区系特点 总被引:7,自引:0,他引:7
作者根据1990—1997历年对浙南岛屿潮间带生态调查所获的材料,分析了该地区蟹类的区系特点。经整理鉴定计蟹类97种,隶属于12科56属,其中软相70种、硬相32种,硬、软相皆有出现的为5种。该地区蟹类区系以亚热带暖水性种类占优势,其次为暖温带性种类,属印度──西太平洋区系区的中国──日本亚区。蟹类的组成与分布受到海流、底质、潮汐等综合因素的影响。 相似文献
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For almost a century, leaf margin analysis has been an important method of estimating Cenozoic paleotemperatures. However, the relation between the proportion of toothed versus entire leaves and temperature has so far been calibrated and characterized using relatively small numbers of opportunistically and irregularly collected floras.Here we present the results of the first systematic spatially-distributed analysis of the relation between leaf margins and temperature for North America.We used species range maps of native North American dicot trees to derive synthetic local floras for each 50 km grid cell in the USA and Canada, and compared the percentage of entire-margined species with the mean annual temperature in each cell. Leaf margin type for each species was assigned using illustrations from appropriate regional North America floras.This analysis confirms that high-rainfall areas of the eastern USA and Canada show a strong inverse relationship between toothed margin percentage and mean annual temperature in the range 0–25 °C. The values we estimate are roughly similar to those obtained from floras in east Asia and previous analyses in North America, but the detailed curve is more complex, showing a distinct change in slope above a mean annual temperature of 20 °C. Wetter climate areas of the coastal western USA do not show any significant correlation between leaf margin percentage and temperature. This may relate to the confounding effect of the diverse topography of the West Coast, or it may be caused by the depleted dicotyledonous tree flora of this area.Like previous studies, this paper demonstrates that there indeed is a strong relationship between leaf margin percentage and temperature on a regional scale in eastern North America. However the relationship does not have the same linear behavior as results obtained from previous analyses. We discuss the implications of the results obtained here for paleoclimatic reconstruction in the content of other leaf margin analyses based on North American sites. 相似文献
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