Earthworm invasion into previously earthworm-free temperate and boreal forests
Earthworm invasion into previously earthworm-free temperate and boreal forests
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DOI：
10.1007/s10530-006-9019-3
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发表时间：
2006-09-01
影响因子：
2.9
通讯作者：
Reich, Peter B.
中科院分区：
文献类型：
--
作者：
Frelich, Lee E.;Hale, Cindy M.;Reich, Peter B.
蚯蚓是一种重要的有害生物，它可以通过改变苗床条件、土壤特性、水、养分和碳的流动以及植物与草食动物的相互作用来影响初级生产者。欧洲蚯蚓入侵了北美以前没有蚯蚓的温带和北方森林，这些森林以宏、栎属、桦树、松树和杨树为主，这为观察蚯蚓如何改变生态系统提供了充分的机会。影响因土壤母质、土地利用历史和入侵蚯蚓物种的聚集而异。蚯蚓减少了有机层的厚度，增加了土壤的容重，并将凋落物和腐殖质物质并入土壤剖面的更深层次，从而影响整个土壤食物网和地上植物群落。有机和矿物质的混合使土壤微生物区系的分布和群落组成以及维管植物的苗床条件发生了显着变化。在一些森林中，蚯蚓入侵导致土壤中N和P的有效性降低，N和P在土壤中的淋失增加，而这些土壤是细根最集中的地方。蚯蚓可能会导致森林衰退综合症，在蚯蚓入侵期间，箭竹属、灰霉属、紫薇属、延龄草属、紫草属和地衣草属的森林草本植物会大量减少。入侵后植物恢复的程度在不同的地点差异很大，取决于与土壤过程和草食动物的复杂相互作用。这些变化可能改变植物物种之间的竞争关系，可能促进外来植物物种入侵北美森林，导致演替轨迹发生迄今未知的变化。
Earthworms are keystone detritivores that can influence primary producers by changing seedbed conditions, soil characteristics, flow of water, nutrients and carbon, and plant-herbivore interactions. The invasion of European earthworms into previously earthworm-free temperate and boreal forests of North America dominated by Acer, Quercus, Betula, Pinus and Populus has provided ample opportunity to observe how earthworms engineer ecosystems. Impacts vary with soil parent material, land use history, and assemblage of invading earthworm species. Earthworms reduce the thickness of organic layers, increase the bulk density of soils and incorporate litter and humus materials into deeper horizons of the soil profile, thereby affecting the whole soil food web and the above ground plant community. Mixing of organic and mineral materials turns mor into mull humus which significantly changes the distribution and community composition of the soil microflora and seedbed conditions for vascular plants. In some forests earthworm invasion leads to reduced availability and increased leaching of N and P in soil horizons where most fine roots are concentrated. Earthworms can contribute to a forest decline syndrome, and forest herbs in the genera Aralia, Botrychium, Osmorhiza, Trillium, Uvularia, and Viola are reduced in abundance during earthworm invasion. The degree of plant recovery after invasion varies greatly among sites and depends on complex interactions with soil processes and herbivores. These changes are likely to alter competitive relationships among plant species, possibly facilitating invasion of exotic plant species such as Rhamnus cathartica into North American forests, leading to as yet unknown changes in successional trajectory.