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The Hockham Mere pollen data shows the rates of change in levels of vegetation using pollen samples from within the Holocene period. Hockham Mere is the site of a former lake, >400 metres diameter, in Norfolk, East Anglia. Its biogenic sediments contain a late-Devensian & Holocene pollen record. This data can be analysed using temperature proxies to help determine climate change in the area at that time. These proxies can be the amount of pollen found in the sample, as more pollen would indicate higher flora productivity which would suggest a warmer climate. The same can be seen if data shows negligible amounts of pollen which would suggest a cooler climate. These are proxies for temperature, and not an accurate record as there are many variances that cannot be monitored easily. == Problems with temperature readings == We cannot use the climate temperature values as actual recordings for the climate in the past. Elements such as the wind will have an effect on the amount of pollen found at the Hockham Mere site in Norfolk. Pollen may not be found in the sample due to it being transported elsewhere, not due to decreased floral productivity. Also volcanic ash in the stratosphere can cause a reduction in the amount of solar energy that can reach vegetation and the ground, which would result in a global cooling effect, if there is enough ash present. This effect on temperature and the climate would be separate from any climate change. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hockham Mere」の詳細全文を読む スポンサード リンク
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