An improved open-top chamber warming system for global change research

Abstract

This study is an assessment of an improved temperature warming system developed to enhance global warming research-based forest ecosystem and soil ecophysiological experiments. The architecture couples a standard open-top chamber (OTC) with a heating cable. A 16 m wire cable with an 18 W m and 288 W h power rating was coiled around a polyvinyl chloride (PVC) pipe 2.5 m in length and 3.5 cm in diameter. The pipe was reshaped into a circle and fixed inside the OTC at a height of 15 cm. PVC pipe distance to plants was 10 to 15 cm while distance to OTC inner walls was 15 cm. The cable was constructed from a heating source with an alloy resistance wire, an aluminum foil and copper wire shielded layer, a crosslinking polyethylene inner insulator, a PVC coating, and a tinned copper grounding wire. After the cable is powered up, air and soil inside the OTC-cable system is heated by conductivity. Temperature is manipulated according to the voltage and resistance of the cable. The OTC-cable system was developed to examine plant reaction to an increase in air and soil temperatures by 2.84 °C and 1.83 °C, respectively. Temperature values are adjustable by changing cable and PVC pipe length. It offers a new, affordable, low energy consumption and low running cost method by which to study climate change effects on forest ecosystems. This method is especially useful for application in forest ecosystems of many developing countries or in many remote areas of developed countries where the feasibility in supplying sufficient power from local power grids is questionable.-1-1