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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/0.06m2)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。
In order to understand the characteristics of soil seed bank of shrub vegetation in the dry valley of Minjiang River and to predict the potential of natural regeneration of shrub vegetation, the soil seed bank “germination method” (15 2m × 2m soil subsoil, 0-5cm soil layer and 5-10cm soil layer) and field survey methods (15 sampling plots of 1m × 1m in each area) were studied in three sections of the dry valley of the Minjiang River (Wenchuan section of the lower reaches of the valley, The core area of Maoxian and the upper reaches of Songpan section) soils shrub vegetation soil seed bank and its relationship with aboveground plant communities. It was found that 4274 seedlings were found in soil seed bank germination test, belonging to 113 species. The average seed density (ind./m2) and the average number of species (species / 0.06m2) in the soil seed bank in the marginal area were higher Central location (Mao County) high. The soil seed bank and the aboveground vegetation in the three plots were mostly perennials. There was no significant correlation between the density and species number of aboveground shrubs and their soil seed bank. The Sorensen similarity index of species composition was low, less than 30% , But the soil seed bank has higher species richness than aboveground vegetation. Comprehensive analysis showed that the dry valley of Minjiang River has the potential of relying on the soil seed bank for natural regeneration. However, due to the low similarity of species composition, once the existing shrub vegetation has been destroyed, the natural restoration to the existing vegetation by soil seed bank alone is Difficulties include the need to actively and fully adopt a strategy of artificially promoting natural recovery based on the assessment of natural recovery potentials, while also taking full account of the spatial heterogeneity of the dry valley vegetation and its natural renewal potential. The identification of soil seed bank characteristics of shrub vegetation in the dry valley of Minjiang River is the basis for understanding the natural renewal potential of shrub vegetation and an important basis for the rational formulation of vegetation restoration and management measures in this area.