Open-top designs for manipulating field temperature in high-latitude ecosystems
Open-top designs for manipulating field temperature in high-latitude ecosystems
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DOI：
10.1111/j.1365-2486.1997.gcb136.x
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发表时间：
1997-12-01
影响因子：
11.6
通讯作者：
Virginia, RA
中科院分区：
文献类型：
--
作者：
Marion, GM;Henry, GHR;Virginia, RA
被动开顶装置已被提议作为一种实验性提高高纬度生态系统温度的方法。然而，关于这些设备的功效的文献很少。本文研究了北极和南极洲六个地点用于改变温度的四个开顶室的性能。大部分加热效应是由于白天气温高于环境温度所致；夜间偶尔会低于环境温度，尤其是气温，导致日平均气温下降。四个北极地点的日平均气温普遍上升了1.2-1.8摄氏度；但偶尔也会出现温度下降的情况。在南极地点的最佳条件下（干燥土壤、无植被、高辐射），平均每日土壤温度增加了 +2.2 摄氏度（-10 厘米）至 +5.2 摄氏度（0 厘米）。在为开放式装置内的植物生长提供有利的环境方面，防风可能比温度本身发挥更重要的作用。风速对日平均气温普遍产生负面影响。每日全球辐射与室温度反应呈正相关和负相关。冰室对积雪的影响各不相同，亚历山德拉峡湾地点显示冰室积雪增加，但融雪日期没有差异，而在深降雪地点的 Latnjajaure，冰室融雪提前 1-2 周，可能会延长生长季节。选择被动升温系统需要平衡所需的升温与潜在的不良生态影响，例如室过热和光线、湿度和风的改变。一般来说，升温系统越封闭，升温效果越高，但生态效应也越大。开顶室可显着改变温度并最大限度地减少最不利的生态影响；因此，这些房间是研究高纬度生态系统对变暖的反应的有用工具。
Passive open-top devices have been proposed as a method to experimentally increase temperature in high-latitude ecosystems. There is, however, little documentation on the efficacy of these devices. This paper examines the performance of four open-top chambers for altering temperature at six sites in the Arctic and Antarctica. Most of the heating effect was due to daytime warming above ambient; occasional night-time cooling below ambient, especially of air temperatures, depressed mean daily temperature. The mean daily temperatures at four arctic sites were generally increased by 1.2-1.8 degrees C; but occasionally, temperature depressions also occurred. Under optimal conditions at the antarctic site (dry soils, no vegetation, high radiation) mean daily soil temperatures were increased by +2.2 degrees C (-10 cm) to +5.2 degrees C (0 cm). Protection from wind may Flay a more important role than temperature per se in providing a favourable environment for plant growth within open-top devices. Wind speed had a generally negative impact on mean daily temperature. Daily global radiation was both positively and negatively related to chamber temperature response. The effect of chambers on snow accumulation was variable with the Alexandra Fjord site showing an increased accumulation in chambers but no difference in the date of snowmelt, while at Latnjajaure in a deep snowfall site, snowmelt occurred 1-2 weeks earlier in chambers, potentially increasing the growing season. Selection of a passive temperature-enhancing system requires balancing the temperature enhancement desired against potential unwanted ecological effects such as chamber overheating and altered light, moisture, and wind. In general, the more closed the temperature-enhancing system, the higher is the temperature enhancement, but the larger are the unwanted ecological effects. Open-top chambers alter temperature significantly and minimize most unwanted ecological effects; as a consequence, these chambers are a useful tool for studying the response of high-latitude ecosystems to warming.