西北沙区4种能源树种评价研究

An Evaluation Study on Four Energy Tree Species in Northwest Sandy Areas

运用开放式气体交换Li-6400便携式光合作用测定系统和热值测定仪对乌兰布和沙漠4种人工林能源树种进行了测试分析,研究了生物量、热能产出、净光合速率、蒸腾速率及水分利用效率特征。结果表明:4种植物均具有较高的生物量、平茬后再生能力强、热能产出高等特点。6年生植株生物量均在8 t/hm2以上,其中梭梭、沙棘、沙枣和沙拐枣分别为23、17、12和8.9t/hm2;单位面积热能产出:梭梭、沙棘、沙枣和沙拐枣分别为435、322、222和158 GJ/hm2;4种植物按单位面积生物量和热能产出指标综合排序:梭梭>沙棘>沙枣>沙拐枣;按水分利用效率排序:沙枣>梭梭>沙棘>沙拐枣。研究指出:选择沙生植物作为能源树种,除了考虑其生物量、热值指标外,还应注意植物在平茬后的再生能力及其水分生态生理特征。

Li-6400 portable photosynthesis system and calorimeter were used to carry through the test analysis of 4 planted energy tree species Haloxylon ammodendron （ HA ）, Hippophae rhamnoides（ HR ） , Elaeagnus angustifolia （ EA ） and Calligonum mongolicum（CM） in Wulanbuh Desert, northwest China to study their characteristics of biomass, heat energy output, photosynthetic rate, evaporation rate and water use efficiency. The results show that all of the 4 species have the characteristics of high biomass, strong regeneration ability after stubble and high heat energy output. Take 6-year-old trees of the 4 species as an example, the biomass are above 8 t/hm^2 averagely, and 23 t/hm^2 for HA, 17 t/hm^2 for HR, 12 t/hm^2 for EA and 8.9 t/hm^2 for CM respectively. The heat energy output is 435 GJ/hm^2（HA）, 322 GJ/hm^2（HR）, 222 GJ/hm^2（EA） and 158 GJ/hm^2 （CM）. Taxis of the 4 species thus obtained： HA 〉 HR 〉 EA 〉 CM according to their biomass and heat energy output and EA 〉 HA 〉 HR 〉 CM according to WUE. The study also indicated that if psammophytes are selected as energy species, the regeneration ability after stubble and water ecophysiology character should be considered besides biomass and data of calorific value.