How land-use intensity affects sexual and parthenogenetic oribatid mites in temperate forests and grasslands in Germany

Katja Wehner,Nadja K Simons,Nico Blüthgen,Romina Schuster,Roy A Norton,Michael Heethoff

doi:10.1007/s10493-020-00586-z

Abstract

Intensive land use has been shown to alter the composition and functioning of soil communities. Due to their low dispersal ability, oribatid mites are particularly vulnerable to land-use intensification and species which are not adjusted to management-related disturbances become less abundant. We investigated how different land-use parameters in forests and grasslands affect oribatid mite diversity and abundance, with a focus on: (1) species-level impacts, by classifying species as increasing (‘winners’) or decreasing (‘losers’) in abundance with higher land-use intensity, and (2) reproductive impact, by investigating whether sexual and parthenogenetic species react differently. We collected 32,542 adult oribatid mites in 60 forests and grasslands of known land-use intensity in two regions of Germany. Diversity and total abundance as well as the proportion of sexual species were higher in forests than in grasslands. Diversity declined with higher land-use intensity in forests, but increased with higher mowing and fertilization in grasslands. Depending on land-use parameter and region, abundance either declined or remained unaffected by increasing intensity. Gravidity was higher in sexual than in parthenogenetic species and sexuals had 1.6× more eggs per gravid female. Proportions of sexual species and gravid females decreased with land-use intensity in forests, but increased with mowing in grasslands. At the species level, 75% of sexuals and 87.5% of parthenogens were ‘losers’ of higher percentages of dead wood originating from management-related disturbances. Across land-use parameters and habitats, a similar proportion of sexual and parthenogenetic oribatid mite species were ‘losers’ of high land-use intensity. However, ‘winner’ species were more common among sexuals.

Highlights

Land-use intensification in forest and grassland habitats is often negatively correlated with the abundance and diversity of plant and animal taxa due to substantial changes in the environment (e.g., Altwood et al 2008; Birkhofer et al 2008; Culman et al 2010; Allan et al 2015)
We focused on (1) what impact of land-use intensity can be seen on the species-level of oribatid mites, and (2) whether sexual and parthenogenetic oribatid mite species are differently affected
17,611 adult oribatid mite individuals were collected in the Swabian Alb and 14,931 in the Schorfheide, belonging to 100 taxa in total (Table 1)

Summary

Introduction

Land-use intensification in forest and grassland habitats is often negatively correlated with the abundance and diversity of plant and animal taxa due to substantial changes in the environment (e.g., Altwood et al 2008; Birkhofer et al 2008; Culman et al 2010; Allan et al 2015). In forests, intensive tree harvesting or the cultivation of non-native trees for the wood industry changes tree composition and influences the availability of resources in the soil food web system (Klarner et al 2014). As these changes have a negative impact on biodiversity, the local and global impact of land-use intensity in forests and grasslands has increasingly been studied over recent decades (e.g., Marshall 2000; Allan et al 2015; Birkhofer et al 2012, 2017; Gossner et al 2016; Penone et al 2019). Depending on the arthropod group, up to 50% of all species in a community were significantly less abundant under conditions of high land-use intensity (called ‘losers’; Chisté et al 2016, 2018; Mangels et al 2017)

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