Biomass and Diversity of Soil Mite Functional Groups Respond to Extensification of Land Management, Potentially Affecting Soil Ecosystem Services

Abstract

Soil mites (Acari) are ubiquitous in soil ecosystems and show a vast taxonomic diversity with a wide range of life history characteristics and feeding strategies. Various taxa contribute directly or indirectly to soil processes, including nutrient cycling, soil formation and pest control. Mites thus support important ecosystem services of soils. Yet, their community composition, and therewith service provisioning, may differ between for instance intensively managed agricultural soils and extensively managed grassland soils. We therefore hypothesized that successional changes in the abundance and diversity of soil mite functional groups (feeding types) will occur following a conversion of arable land to grassland, affecting their contribution to ecosystem services. To test this, we studied the succession of mite communities on two Long Term Observatories (LTOs) in Lusignan (France) and Veluwe (the Netherlands). At Lusignan, sampling involved four combinations of recent and historic land use types. At the Veluwe, samples were taken in a secondary succession chronosequence in grasslands, representing a time frame up to 29 years after the conversion from arable land to grassland. Biodiversity and biomass were higher in grassland than in arable land, especially for the total mite community, the predators and the main taxa aiding in decomposition. After conversion of grassland to arable land, or vice versa, both taxon richness and biomass rapidly developed towards the prevailing conditions. Our results indicated that the taxon richness and biomass of the total mite community in grassland still continued to increase up to 29 years after the conversion from arable land to grassland. Total taxon richness increased with time since conversion, which was mainly due to the immigration of decomposers and predators. The biomass of different feeding guilds increased at variable speeds. The observed changes imply an increase in nutrient cycling and in the suppression of some potential pests. We discuss the relevance of these ecosystem services in extensively managed grasslands and agricultural systems. Furthermore, our results suggest that in agricultural rotational schemes that include one or more years of grassland, mite communities and associated ecosystem services may be partially, but not completely, restored to the conditions of long term grassland.

Climate change and intensive land use reduce soil animal biomass through dissimilar pathways

“…In contrast, grasslands with less extensive management practices, and more diverse plant communities, which provide an environment with more habitats and more accessible food sources, can maintain higher densities of soil organisms (Alvarez et al, 2001; Nyawira Muchane, 2012; Scherber et al, 2010). Accordingly, we found significantly higher levels of microarthropod biomass in grasslands than in croplands, which is supported by previous studies (e.g., de Groot et al, 2016).…”

Climate change and intensive land use reduce soil animal biomass via dissimilar pathways

“…Compared with croplands, grasslands (with less intensive disturbance but more diverse plant communities) provide an environment with more habitats and more accessible food sources, can maintain higher densities of soil organisms ( Alvarez et al, 2001 ; Nyawira Muchane, 2012 ; Scherber et al, 2010 ). Accordingly, we found significantly higher levels of microarthropod density and biomass in grasslands than in croplands, which is supported by previous studies (e.g., de Groot et al, 2016 ). Similarly, microarthropod density and biomass are expected to be also reduced by the intensified management practices, e.g., monoculture, heavy use of mineral fertilizers and pesticides in croplands, and frequent fertilization, mowing, and grazing in grasslands; however, we did not find any evidence for this in the present study.…”

Soil mite communities (Acari: Mesostigmata) as indicators of urban ecosystems in Bucharest, Romania

“…In Europe, these species have been identified mostly in grasslands, grassy arable fallows or urban habitats, their communities being correlated with soil moisture ( Onchodellus karawaiewi being a euryhygrophilous species) or organic matter content. In our study, this explains the relationship between such mites and RP 20 , 25 , 44 , 60 , 79 .…”

“…Research studies from all over the world revealed that the Mesostigmata communities correlated with environmental variables could constitute a very useful biological tool to characterized the ecological quality of terrestrial ecosystems and the quality of soils 9,10,18,21,[25][26][27][29][30][31]33 . In the case of urban green areas from Bucharest, under different management scenarios, their ecological characterization was made taking into account the variation of the environmental parameters, in correlation with spatial dynamics of the communities' parameters of Mesostigmata fauna (species diversity and numerical abundance).…”

“…Together with other small soil invertebrates (springtails, enchytraeids, insect larva, oribatids), they participate indirectly in the decomposition process and ultimately affect soil quality (fertility and productivity) 4 , 10 . At the same time, they are the main regulator of the other soil invertebrate populations 11 , 24 , 25 . Most species prefer habitats rich in organic matter, with high soil moisture, medium soil temperature and a low pH 26 – 28 .…”