【摘要】 本文讨论了山东省沂南县沂河林场不同密度Ⅰ-72杨人工林的投入产出及经济成熟龄。投入分为一次性投入和每年投入。一次性的总投入量为2 33 1.00元/ha,其中整地占84％;平均年投入为253.21元/ha·a,其中追肥占74％。文中还计算了长期占用资金的复利。对各密度的年投入量、年生长量、年产值、年均净产值及其年动态进行了研究,同时做了林木的年均生长量和年均净产值数学模拟。杨树人工林在造林后第三年才能获得利润。数量成熟龄为6～10年,年均最高生长量可达25.252 1 m~3/ha·a。经济成熟龄为6～7年,年均最高净产值可达6 110.52元/ha·a。杨树人工林的数量成熟龄与经济成熟龄主要受密度及投入成本的影响。更多还原

【Abstract】 In three different kinds of planting spacing of Poplar plantations, the input-output and financial maturity were studied and discussed in Yinan County, Shandong Province. In the plantation rotation, some input were finished once; and some input needed to be done every year. The former of the input were 2331.00 yuan/ha, and the ground preparation counted for 84%. The latter, the mean annual inputs were 253.21 yuan/ ha.a, and 75 percent of them were the expenses of the top application. The interest of the expenses and the net income were calculated. The annual input, annual income, annual net income and the mean annual net income were studied in the different kinds of planting spacing of Poplar plantations, and some incomes were showed with equations by statistical regression. Generally, we can get net income at third year after afforestation. The number of years for the quantity rotation were 6~10 years, and the highest mean annual income was 25.252 1 m3/ha.a. The number of years for the financial rotation were 6~7 years, and the highest mean annual fixed net income was 6 110.00 yuan/ha.a. The financial maturity mainly depended on the input and planting spacing.更多还原