Tree Species Identity Shapes Earthworm Communities

Abstract

Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden experiment, replicated six times over Denmark, six tree species were planted in blocks: sycamore maple (Acer pseudoplatanus), beech (Fagus sylvatica), ash (Fraxinus excelsior), Norway spruce (Picea abies), pedunculate oak (Quercus robur) and lime (Tilia cordata). We studied the chemical characteristics of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer and Tilia, which is related to calcium-rich litter and low soil acidification. Epigeic earthworms were indifferent to calcium content in leaf litter and were shown to be mainly related to soil moisture content and litter C:P ratios. Almost no earthworms were found in Picea stands, likely because of the combined effects of recalcitrant litter, low pH and low soil moisture content.

Litter quality, land-use history, and nitrogen deposition effects on topsoil conditions across European temperate deciduous forests

“…These litter quality results agree with other studies that demonstrate the key role that litter 562 quality has for decomposition processes that ultimately determine many of the topsoil 563 conditions in forests (Cools et al, 2014;Djukic et al, 2018;Schelfhout et al, 2017). Temperate 564 forest soils receive large amounts of litterfall year after year (e.g.…”

“…It can influence nutrient cycling and thus soil conditions directly through for example the variation in chemical composition of the litter (Bauters et al, 2017;Kooch, Samadzadeh, & Hosseini, 2017) or indirectly through for example effects on the size and composition of soil macro-and micro-fauna communities (e.g. earthworms: De Wandeler et al, 2018;Schelfhout et al, 2017).…”

Effects of Mineral Soil and Forest Floor on the Regeneration of Pedunculate Oak, Beech and Red Oak

“…Soil nutrient availability has been shown to be affected by tree species composition, through species and diversity effects on litter decomposition rates and thus nutrient release [17][18][19]. However, our three study species, the main tree species of the TREEWEB platform, have a similar and relatively low leaf litter quality [32,48], and tree species composition effects on soil properties were limited within the platform [32]. Even though base saturation and soil bulk density showed significant differences between the different tree species, the range of these soil conditions might be too small to show clear effects on the seedlings of these tree species.…”

Woodland restoration on agricultural land: long‐term impacts on soil quality

“…As observed in our study, the surface water gley soils tend to fall within a pH range of between 5 and 6 due to a high clay content, nutrient content, and calcium carbonate secondary formations (Benham et al ). Soil pH, as well as earthworm population responses to woodland restoration on agricultural land, are highly dependent on the tree species planted and the associated litter quality and quantity (Muys ; Muys et al ; Curry ; Rajapaksha et al ; Schelfhout et al ). Tree species identity has been shown to be more important than tree diversity in driving earthworm communities in European forests (De Wandeler et al ).…”