岷江上游干旱河谷引种番麻的生态适应性及生物量预测模型

Growth and allometric biomass equations of introduced Agave americana L. in upper reaches of Mingjiang River

以岷江上游干旱河谷地区引种的番麻为研究对象,通过对不同海拔番麻的株高、冠幅、单株叶片数以及萌芽数等生长指标的调查研究结果,了解其在干旱河谷区的生长分布上限,为该地区与类似地区引种该品种相关物种提供理论依据;同时,利用株高等简单生长指标与番麻生物量的关系进行拟合,建立预测方程。通过高度、冠幅、单株叶片数、萌芽数(株/100m2)等生长指标比较表明,番麻的最适生长区为海拔1400～1500m。在干旱河谷阳坡的生长上限为海拔1800m,往上仅能成活,不能自身繁殖。根据番麻的株高、冠幅、叶片数等简单生长指标与生物量呈显著相关(P<0.01),分别建立了相应的回归模型,其中地上生物量和单株生物量的最优回归模型R2值均在0.90以上,地下生物量的最优回归模型R2值也在0.75以上。

Agave americana L. , a drought-tolerant plant with high-value of medicinal use, was introduced to the arid valley of the upper reaches of the Mingjiang River in 2000. In order to evaluate it role in vegetation restoration and determine the optimal adaptation range in the area, plant traits such as height, crown diameter, leaf number and sprouts were measured along altitude ranging from 1400m to 2000 m for the purposes of assessing growth conditions and estimating above- and below-ground biomass. It was found that 1400 -- 1500m above sea level is the optimal growing area of Agave americana. The mean height, crown diameter, leaf number and sprouts in this altitude were up to 62.7 cm, 0. 385 m^2, 22 blades, 27 buds, which are larger than those in other altitudes. The upper limit of Agave americana is 1800 m and it can only survive but not reproduce above this altitudinal limit. The biomass is significantly correlated with height, crown diameter and leaf number, which can be used for estimating above- and below-ground biomass through established allometric biomass equation.