Purpose

Soil diaspore banks of bryophytes are poorly known in tundra grasslands, yet can be important for the maintenance of local bryophyte assemblages. We examined the effects of fertilization and grazing exclusion on above-ground bryophyte assemblages and soil diaspore banks in a tundra grassland.

Methods

We collected soil diaspore samples and recorded the cover of above-ground bryophytes from a full-factorial experiment with NPK fertilization and grazing exclusion treatments (a Nutrient Network site in NW Finland). Soil diaspore samples were germinated on trays in a greenhouse. We analyzed the compositions of diaspore bank assemblages and of above-ground assemblages and assessed their responses to the experimental treatments.

Results

The diaspore bank contained c. 50% of taxa found in above-ground assemblages; 26 bryophyte taxa germinated from the diaspore bank, while 40 taxa were found in the above-ground assemblages. These communities had distinct species compositions: the diaspore bank was dominated by Pohlia nutans, while above-ground assemblages were dominated by several species. NPK fertilization and grazing exclusion had negative effects on bryophyte richness and cover in above-ground assemblages, and weaker effects on these responses in the diaspore bank.

Conclusion

Soil diaspore banks comprise about half of the bryophyte taxa encountered in above-ground assemblages. Bryophyte diaspore banks are more buffered against nutrient enrichment and grazing exclusion than above-ground assemblages, suggesting that diaspore banks may enhance persistence and recovery of local bryophyte assemblages from environmental changes.

中文翻译：

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苔藓植物土壤水铝石库是否缓冲了养分富集和放牧排斥？

目的

苔藓植物的土壤水铝石库在苔原草原上鲜为人知，但对于维持当地的苔藓植物组合可能很重要。我们研究了施肥和放牧对苔原草原地上苔藓植物组合和土壤水铝石库的影响。

方法

我们收集了土壤水铝石样本，并记录了来自 NPK 施肥和放牧排除处理的全因子实验（芬兰西北部的营养网络站点）的地上苔藓植物的覆盖率。土壤水铝石样品在温室的托盘上发芽。我们分析了水铝石银行组合和地上组合的组成，并评估了它们对实验处理的反应。

结果

水铝石银行包含 c。50% 的分类群存在于地上组合中；26个苔藓植物类群从水铝石库发芽，而40个类群在地上组合中被发现。这些群落具有不同的物种组成：水铝石库以Pohlia nutans为主，而地上组合则以几种物种为主。NPK施肥和放牧排斥对地上组合中的苔藓植物丰富度和覆盖度具有负面影响，而对水铝石库中的这些响应的影响较弱。

结论

土壤水铝石库约占地上组合中遇到的苔藓植物分类群的一半。与地上组合相比，苔藓植物水铝石库更能缓冲养分富集和放牧排斥，这表明水铝石库可以增强当地苔藓植物组合从环境变化中的持久性和恢复。