林草复合系统的生态学及经济学效益评价

综合分析和评价了啤特果树Pyrus ussuriensis-紫花苜蓿Medicago sativa、啤特果树-小麦Triticum aestivum两种复合系统的生态学效应和经济效益。结果表明:啤特果树-紫花苜蓿复合系统和啤特果树-小麦复合系统的土壤容重分别为1.39和1.45 g/cm3。啤特果树-紫花苜蓿复合系统中非毛管孔隙度(4.72%)和总孔隙度(58.96%)均大于啤特果树-小麦复合系统中非毛管孔隙度(4.15%)和总孔隙度(50.80%),说明林下种植紫花苜蓿较种植小麦更有利于疏松土壤、改良土壤结构;啤特果树-紫花苜蓿复合系统的不同土壤层土壤含水量均大于啤特果树-小麦复合系统的土壤含水量,说明林下紫花苜蓿比小麦的保水蓄水能力强;紫花苜蓿和小麦的茎叶持水率分别为37.3%和25.8%,说明林下紫花苜蓿更能减少地表径流,从而减轻水土流失;紫花苜蓿比小麦更能有效地缓解地面温度的激增和激减;种植紫花苜蓿比种粮食作物多收入3 900~8 850元/hm2。因此林下种植紫花苜蓿较种植小麦具有显著的生态效益和经济效益。

An analysis of economic benefit and social effect of Pi Te apple-alfalfa complex ecosystem

The objective of this research was to compare the ecologic and economic benefit of Pi Te apple(Pyrus ussuriensis)-alfalfa(Medicago sativa) and wheat(Triticum aestivum)-alfalfa complex ecosystem in Linxia,Gansu Province.Soil bulk density was 1.39 and 1.45 g/cm3,non-capillary porosity was 4.72% and 4.15%,and overall porosity was 58.96% and 50.80%,respectively.Soil holding water capacity in the first ecosystem was higher than that in the second.Water-holding rate in leaves-stems of alfalfa and wheat was 37.3% ...