九寨沟宽叶香蒲的生长特征及收割对其生长影响

Characteristic of Typha latifolia Growth and Harvest Influence on Its Growth

宽叶香蒲（Typha latifolia）群落是九寨沟芦苇海中第二大植物群落,发挥着重要的生态功能和景观功能。每年冬季枯死的地上植株部分堆积在芦苇海中,导致湖床不断抬升,成为加快芦苇海向沼泽化趋势演变的因素之一。对该湖泊宽叶香蒲群落的生长特征、生物量贡献及凋落物收割处理对宽叶香蒲生长特征的影响进行了研究。结果表明,在宽叶香蒲生长期内,可以利用以月为自变量的二次回归方程模型,来估算芦苇海宽叶香蒲株高;宽叶香蒲的株高为170~365 cm,平均株高为（266±32）cm;群落密度为17~40株/m2,平均密度为（25±5）株/m2;平均单株地上生物量为（34.82±6.31）g,单位面积生物量为（1 030.41±163.44）g;人工收割处理利于宽叶香蒲的发芽及前期生长;秋末冬初（11月下旬）,对宽叶香蒲进行收割,可以减少芦苇海中因宽叶香蒲凋落物产生的有机物的大量淤积,减缓湖床抬升速度,从而有利于芦苇海的保育。

The community of broad-leaf cattail（Typha latifolia） is the second largest plant community in Luweihai Lake, Jiuzhaigou, and it plays an important role in the ecological function and landscape function. After withering in winter, the aboveground part of Typha latifolia community accumulated in the lake, leading to rising of the lake bed, which finally results in lake-swapping. Studies on the effects of different harvest ratios of broad-leaf cattail on its growth and biomass showed that a quadratic regression model（y =-11.68x2＋130.94x- 115.45, R2= 0.986 3） with the month as its independent variable could be used to estimate the height of the broad-leaf cattail in Luweihai Lake during the plant growth period. The height of the plant ranged from 170-365 cm, average height being（266 ± 32） cm; the density of the community ranged from17-40 individual/m2, the average density being（25 ± 5） individual/m2; the average individual aboveground-biomass was（34.82 ± 6.31） g, the biomass being（1 030.41 ± 163.44） g/m2. Artificial harvest treatment was good for broad-leaf cattail germination and early growth（from April to May）, and it had no significant effect on late growth of the plant and the density of its population（from June to October）. Harvest treatment in late autumn（late November） could reduce the amount of deposition of organic matter produced by broad-leaf cattail in Luweihai Lake, slowed the uplift rate of the lake bed.