图1. 茭草凋落物分解模拟增温与生境差异实验。A, 三种生境包括大气界面、水界面以及土界面。其中, 大气界面中的凋落物袋悬于PVC管上方距离地面1.2 m处; 水界面中的凋落物袋中放入乒乓球使凋落物袋始终悬浮于水中; 土界面中的凋落物袋通过PVC管将其固定在5.0 cm掩埋深度的底泥中。B, 开顶式生长室(OTC)的设计及运行。其中, 对照组无OTC装置, OTC增温组以直径为2.4 m的底座以及直径为2.0 m的开口所设计建造的阳光板为材料, 实现大气增温模拟。2014年12月至2015年12月全年实时采集(1次·h^-1)对照组与OTC增温组中的气温数据, 实现1.5-2.0 ℃温度增幅。C, 研究对象为湿地挺水植物茭草的叶凋落物, 包括增温实验和生境差异实验(其中增温实验对照组和生境差异实验中大气界面的样品相同)。

Fig. 1. Experiment of simulated warming and habitat difference for litter decomposition of Zizania latifolia. A, Three habitats include air interface, water interface, and soil interface. Among them, litter bags under air decomposition were hang over the bamboo (1.2 m from the ground), litter bags under water decomposition were floated in the surface of water (with the aids of table tennis), and litter bags under soil decomposition were fixed by PVC tubes in the soils (5.0 cm in deep). B, The design and operation of Open-top Chamber (OTC). Among them, control group has no OTC devices, and OTC devices simulate rising temperature (warming group). The device was constructed by solar panels with 2.4 m base and 2.0 m opening in diameter. The temperatures between control and warming groups were recorded from December 2014 to December 2015 (once per hour). In warming treatment, the temperature has been raised by 1.5-2.0 ℃. C, The research object was a typical emergent wetland plant, Zizania latifolia. Its leaf litter was subjected to warming and habitat difference treatments.