活立木生物电产生功率及其生境因子影响

Effects of the habitat factors on bioelectric power generated by standing trees

【目的】活立木发电是新兴课题,通过研究活立木生物电产生功率的变化规律,以及活立木生境变化对其产生功率的影响,确定生物电产生功率最大的生境条件,为低能耗森林装备在林内布设最佳环境的选择提供理论依据。【方法】以北方常见树种落叶松和家榆活立木为研究对象,在-15~10℃气温范围内,测量活立木树干距离地面不同高度位置产生的电压和电流以及树木周围的空气温湿度、土壤温湿度和土壤pH值等生境因子,结合土壤-树液等效电路,获得活立木生物电产生功率;统计对生物电功率影响显著性因子,建立功率与主效应生境因子的关系模型,确定活立木生物电产生功率的生境影响规律。【结果】温湿度条件以及土壤pH值均对活立木生物电产生功率有显著影响,其中空气和土壤温度对活立木生物电产生功率影响最显著,土壤湿度和pH值次之,空气湿度最小;电极高度对落叶松产生功率影响显著,且与温湿度条件存在交互作用;活立木生物电产生功率与生境因子的多元关系模型的判定系数分别为0.64~0.97(零上温度)和0.96~0.99(零下温度)。零上温度时,落叶松产生功率约为家榆的2.6倍;零下温度环境中,家榆生物电产生功率相较落叶松好。【结论】依据所建立活立木生物电产生功率与空气温度的关系模型,通过空气温度变化即可预测生物电产生功率大小,确定最佳生物电收集的环境条件。当温度在0℃以上时,落叶松可作为生物电收集倾向树种;当温度低于0℃时,家榆可作为生物电收集的倾向树种。

【Objective】Bioelectricity generated by standing living trees is a new topic. In this work, by studying the influence of different habitat factors on the power of the bioelectricity generated by living trees and its variation law, the habitat conditions with the highest bioelectric power generation were determined to provide a theoretical basis for the optimal environment selection for the low-energy consumption equipment in the forest.【Method】The common tree species in northern China, Larix gmelinii and Ulmus americana, were selected as the research objects. The voltage and current of living trees, temperature and relative humidity of air and soil, soil pH and other habitat factors around the trees were measured in the temperature range of-15℃ to 10℃ at different heights of the tree trunk. Combined with the soil-sap equivalent circuit, bioelectric power was calculated. The significant factors affecting bioelectric power were determined by statistical analysis. The relationship model between the bioelectric power and the main habitat factors was established to determine the influencing law of different habitat factors on the bioelectric power generated by living trees.【Result】The results showed that temperature, humidity and soil pH all had significant effects on the bioelectricity power generated by living trees.Among them, air and soil temperature had the most significant effect, followed by relative soil humidity and soil pH. The influence of relative air humidity was relatively weak. The height of the electrode had a significant effect on the power generation of Larix gmelinii,which interacted with temperature and humidity conditions. The relationship model between the bioelectric power of living trees and the habitat factors was determined, whose coefficients of determination were 0.64-0.97(above zero temperature) and 0.96-0.99(below zero temperature), respectively. The bioelectric power generated by Larix gmelinii was about 2.6 times that of Ulmus americana When the temperature was above zero, the bioelectric power generated by Ulmus americana was better.【Conclusion】 According to the established relationship model between air temperature and the bioelectric power of living trees, the power could be predicted by the air temperature change, and the optimal environmental conditions for bioelectricity collection could be determined. When the temperature was above 0℃, Larix gmelinii could be used as the tree species for bioelectricity collection. Ulmus americana could be used for bioelectricity collection when the temperature was below 0℃.