浙江省杉木林生产力地理分异特性

杉木Cunninghamia lanceolata林是浙江省主要的森林类型之一。为科学合理地开展杉木经营管理，提高森林生态系统质量和效益，以1994-2009年浙江省森林资源连续清查数据为基础，采用生物量换算因子连续函数法计算森林生产力，以平均划分的原则将经度、纬度和海拔3个维度分别划分成几个半度带称之为梯度带，用最小显著差法分别计算差异显著性，分析杉木林生产力的地理分异特性及规律。结果表明:浙江省杉木林生产力在经度方向上差异显著(P < 0.05)，第Ⅰ和第Ⅱ梯度带上的生产力明显高于其他梯度带上的生产力且其他梯度带间的生产力差异不显著(P>0.05)；在沿纬度方向上差异不显著，但各梯度带上的生产力波动规律一致；在海拔方向上差异不显著(P>0.05)，但随时间推移第Ⅴ梯度带的生产力明显高于其他梯度带上的生产力。总体上，浙江省杉木林生产力在经度方向上存在明显分异现象，在纬度和海拔2个地理维度上无明显分异现象，但随时间推移有分异趋势，分异现象逐渐明显。浙江省杉木林在118°~119°E之间培育可能会具有更高的生产力。

Geographical differentiation characteristics influencing productivity of Cunninghamia lanceolata forests in Zhejiang Province

To scientifically and reasonably carry out forest management and to improve quality and benefits of the forest ecosystem for a Cunninghamia lanceolata forest, one of the main forest types in Zhejiang Province, this research was conducted based on data from the national forest inventory of Zhejiang Province from 1994 to 2009. The method of variable biomass expansion factor function (BEFF) was used to estimate productivity. According to the principle of average division, longitude, latitude and altitude were divided into several half-degree zones respectively called Gradient Zones. Least-Significant Difference (LSD) was used to estimate significant differences and then analyse geographic differentiation characteristics and rules of productivity for C. lanceolata forests in three dimensions:longitude, latitude, and altitude. Results showed that productivity of C. lanceolata forests in Zhejiang Province along the longitudinal direction had significant differences (P < 0.05). Productivity in Gradient Zones Ⅰ and Ⅱ were obviously higher than productivity in other gradient zones, and differences among other gradient zones were not significant (P>0.05). Along the latitudinal direction, there were no significant differences (P>0.05) for productivity in zones, but the law of productivity fluctuation in gradient zones was consistent. In the altitudinal direction there were no significant differences (P>0.05) for productivity in Zones. As time went on, productivity of Gradient Zone Ⅴ was higher than productivity in Gradient Zones Ⅰ-Ⅳ. Generally speaking, then, productivity of C. lanceolata forests in Zhejiang Province had differentiation in the longitudinal direction but not in latitudinal and altitudinal directions; however, over time, differentiation was noticeable. C. lanceolata forests in Zhejiang Province cultivated in longitude 118°-119°E would have higher productivity.