Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China; School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou 450045, China; School of Nature Conservation, Beijing Forestry University, Beijing 100083, China.
Biology Department, University of Massachusetts, Amherst, MA 01003, USA.
Sci Total Environ. 2020 Mar 15;708:134941. doi: 10.1016/j.scitotenv.2019.134941. Epub 2019 Nov 2.
Spatial heterogeneity of soil nutrients and earthworm activity can each increase the performance of plant species, but their interactive effects have been little studied. The ability of plants to forage for nutrients by concentrating roots where nutrients are concentrated can partly explain the positive effects of nutrient heterogeneity, but whether root foraging can help explain the positive effects of earthworm activity is untested. We conducted a greenhouse experiment in which we grew eight species of Poaceae in homogeneous and heterogeneous soils with or without the earthworms Eisenia fetida and Metaphire guillelmi and measured net accumulation of plant mass and tillers. Effects of heterogeneity and earthworms on plant performance were positive in most species. The presence of earthworms reduced the directly measured effect of heterogeneity on total mass in some grass species. Most species showed root foraging ability. Ability showed no relationship to effects of heterogeneity or earthworms on final total dry mass. However, earthworms reduced foraging in some species, possibly by lessening heterogeneity. Earthworm activity in heterogeneous soil may thus reduce the benefits of root foraging for nutrients in plants.
土壤养分和蚯蚓活动的空间异质性都可以提高植物物种的表现，但它们的相互作用却很少被研究。植物通过将根系集中在养分集中的地方来获取养分的能力可以部分解释养分异质性的积极影响，但根觅食是否有助于解释蚯蚓活动的积极影响尚待检验。我们进行了一项温室实验，在有或没有蚯蚓赤子爱胜蚓和威廉环毛蚓的均匀和不均匀土壤中种植了 8 种禾本科植物，并测量了植物质量和分蘖的净积累。在大多数物种中，异质性和蚯蚓对植物表现的影响是积极的。蚯蚓的存在降低了某些草本植物中异质性对总质量的直接测量效应。大多数物种表现出根觅食能力。能力与异质性或蚯蚓对最终总干质量的影响之间没有关系。然而，蚯蚓在一些物种中减少了觅食，可能是因为异质性降低了。因此，蚯蚓在不均匀土壤中的活动可能会降低植物根觅食获取养分的益处。
