Peterjohn William T, Melillo Jerry M, Bowles Francis P, Steudler Paul A
Marine Biological Laboratory, The Ecosystems Center, 02543, Woods Hole, MA, USA.
Oecologia. 1993 Feb;93(1):18-24. doi: 10.1007/BF00321185.
We conducted several experiments to determine a procedure for uniformly warming soil 5° C above ambient using a buried heating cable. These experiments produced a successful design that could: 1) maintain a temperature difference of 5° C over a wide range of environmental conditions; 2) reduce inter-cable temperture variability to ca. 1.5° C; 3) maintain a temperature difference of 5° C near the edges of the plot; and 4) respond rapidly to changes in the environment. In addition, this design required electrical power only 42% of the time. Preliminary measurements indicate that heating increased CO emission by a factor of ca. 1.6 and decreased the C concentration in the O soil horizon by as much as 36%. In addition, warming the soil accelerated the emergence and early growth of the wild lily of the valley (Maianthemum canadense Desf.). The relationship between CO flux and soil temperature derived from our soil warming experiment was consistent with data from other hardwood forests around the world. Since the other hardwood forests were warmed naturally, it appears that for soil respiration, warming the soil with buried heating cables differs little from natural, aboveground warming. By warming soil beyond the range of natural variability, a multi-site, long-term soil warming experiment may be valuable in helping us understand how ecosystems will respond to global warming.
我们进行了多项实验，以确定一种使用埋地加热电缆将土壤均匀加热至比环境温度高5摄氏度的方法。这些实验产生了一个成功的设计，该设计能够：1）在广泛的环境条件下保持5摄氏度的温差；2）将电缆间的温度变异性降低至约1.5摄氏度；3）在地块边缘附近保持5摄氏度的温差；4）对环境变化做出快速响应。此外，这种设计仅在42%的时间内需要电力。初步测量表明，加热使二氧化碳排放量增加了约1.6倍，并使O层土壤中的碳浓度降低了多达36%。此外，土壤升温加速了野生铃兰（Maianthemum canadense Desf.）的出苗和早期生长。我们的土壤升温实验得出的二氧化碳通量与土壤温度之间的关系与世界其他阔叶林的数据一致。由于其他阔叶林是自然升温的，因此就土壤呼吸而言，用埋地加热电缆加热土壤与自然的地面升温似乎没有太大区别。通过将土壤加热到自然变异性范围之外，一个多地点、长期的土壤升温实验可能有助于我们了解生态系统将如何应对全球变暖。
