作 者 ：李彦娇,包维楷*,吴福忠
期 刊 ：生态学报 2010年 30卷 2期 页码：399~407
关键词：地上植被；土壤种子库萌发；恢复；物种组成；物种丰富度；
Keywords:aboveground vegetation, germination of seed-bank, restoration, species composition, species richness,
摘 要 ：为了解岷江干旱河谷区灌丛植被土壤种子库的特征及预测灌丛植被自然更新的潜力,利用土壤种子库“萌发法”(每个地段15个2m×2m样方内分土表层、0-5cm土层和5-10cm土层采集土样)及野外植被调查方法(每个地段15个1m×1m的调查样方)，研究了岷江干旱河谷3个地段(河谷下游边缘汶川地段、核心茂县地段以及上游边缘松潘地段)阳坡灌丛植被土壤种子库及其与地上植物群落的关系。发现：土壤种子库发芽试验共观察到4274株幼苗，分属于113个物种。土壤种子库密度在102—103ind./m2，物种数在12—23种/0.06m2，边缘地段的土壤种子库平均种子密度(ind./m2)和平均物种数(种/006m2)均比中心地段(茂县)高。3个地段土壤种子库和地上植被的组成物种均多为多年生植物，地上灌丛与其土壤种子库的密度及物种数均呈不显著相关性；物种组成的Sorensen相似性指数较低，不足30%，但土壤种子库均比地上植被具有更高的物种丰富度。综合分析表明，岷江干旱河谷灌丛具有依靠土壤种子库实现自然更新的潜力，但由于物种组成相似性较低，现存灌丛植被一旦遭到破坏后，单依靠土壤种子库自然恢复到现存植被是困难的，需要在自然恢复潜力评估基础上积极充分采取人工促进自然恢复的策略，同时也应充分考虑干旱河谷植被及其自然更新潜力的空间异质性。探明岷江干旱河谷区灌丛植被的土壤种子库特征，是认识灌丛植被自然更新潜力的基础，是合理制订该区植被恢复与管理措施的重要依据。
Abstract:To evaluate and predict the natural regeneration potential of shrub vegetation in dry valleys, we investigated the soil seed bank and its associated vegetation in the lower (Wenchuan valley), middle (Maoxian valley), and the upper reaches (Songpan valley) of the Minjiang River, using the “seed germination” method. Research sites covered by shrub vegetation are selected on south-facing slopes in the three valleys. Fifteen plots (2 m×2 m) at each site were established for soil seed bank investigation. Soil samples were taken according to soil surface, 0-5 cm and 5-10 cm soil depth. Vegetation investigation at each site was carried out in 15 plots with a size of 1 m×1m. A total of 4274 seeds belonging to 113 species were recorded in soil seed banks. The soil seed bank density was 102-103 ind./m2 and the number of species was 12-23 species/0.06m2. Both the mean seed density (ind./m2) and the mean number of species (species/0.06m2) were found to be lower in Maoxian, the middle reaches of the Minjiang River, than in the other two sites. Most of the species found in the soil seed banks and in aboveground vegetations at the three sites were perennial grasses. Most fruits found were achene, capsule and caryopsis with small seed size. The mean density and the mean number of species of soil seed banks were not correlated with the vegetation covered. The soil seed bank had low similarity (Sorensen′s index<30%) to its associated vegetation in species composition. The species richness in soil seed banks was higher than that in aboveground vegetations. Comprehensive analysis showed that the natural regeneration potential of the shrublands by germination of seed-banks in the dry valleys of the Minjiang River is low. Once the present vegetation is destroyed, the natural restoration of vegetations is hardly possible. Artificial restoration strategy in combination with natural regeneration should be employed, to accelerate recovery of vegetation. In addition, spatial heterogeneity of the existed vegetation and natural regeneration potential should also be considered. The present study provides foundational data for estimating the natural regeneration potential of vegetation and developing restoration and management strategy for vegetation in the dry valleys of the Minjiang River.
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