Abstract
Abstract The ecosystem services that humans obtain from the soil are strongly linked to the soil's biota. There is ample evidence that intensive agriculture has a negative effect on the soil's biological diversity. While in other ecosystems, habitat specialists are at a higher risk of extinction due to human impacts than generalists, we have no evidence of whether this holds true for soil biota. We calculated the realized niche width for soil nematodes using co‐occurrence data. We compared these with ecological traits. We then calculated an index of community specialization and tested whether land use intensity leads to decreases in the index of community specialization, taxon richness, diversity and to changes in nematode abundance. The resulting realized niche widths did not correlate with ecological traits such as feeding group, body mass or c‐p class. While it is possible that there are no relationships between these traits and the realized niche width, it is likelier that food availability, pH tolerance, or host breadth are more important factors in explaining niche width. Contrary to our expectations, the lowest community specialization levels were found in soils with the lowest human intervention (shrubland–woodland ecosystems), while grasslands, dairy farms and arable farms had an overall higher level of specialization. Weather variables and land use intensity explained 66% of the variation in the index of community specialization in sandy soils. We found highest richness and diversity at intermediate levels of disturbance (grasslands and dairy farms). The lowest abundances were found on shrubland–woodland systems. Dairy farms on sand and clay had similar indices of community specialization, whereas peaty soils fostered a higher proportion of habitat specialists. We argue that farmland supposes a stable environment for organisms with shorter life spans. Agricultural management strives to lower disturbances, allowing shorter lived organisms to escape pressures otherwise present in nature, such as drought or nutrient deficiencies during the growing season. In very disturbed systems, however, specialists may also suffer from negative effects of land use intensity. This co‐occurrence method to assess niche width opens the door to estimating the soil community's niche breadth, for which resource‐based methods are difficult to implement. A free Plain Language Summary can be found within the Supporting Information of this article.
Highlights
Humans derive multiple benefits from the soil system (Sarukhan et al, 2005)
While it is possible that there are no relationships between these traits and the realized niche width, it is likelier that food availability, pH tolerance, or host breadth are more important factors in explaining niche width
The protocol to calculate realized niche width (RNW) using co‐occurrence matrices was initially developed and applied to tree communities, it has since been used to calculate the RNW of, for example, vertebrates (Ducatez et al, 2014). The suitability of this method to calculate the RNWs of such different organisms resides in the simplicity of the idea behind it: a habitat specialist will occur in the company of species that can inhabit the same habitat
Summary
Humans derive multiple benefits from the soil system (Sarukhan et al, 2005). The delivery of these ‘ecosystem services’ depends on a number of soil processes driven by different groups of soil dwelling fauna (Ferris & Tuomisto, 2015; Haygarth & Ritz, 2009; Kibblewhite, Ritz, & Swift, 2008). At the other end of the spectrum are the ‘persisters’, nematodes with a low reproduction rate, a long life cycle, a low colonization ability and sensitive to disturbance This classification has served as a starting point to calculate diverse ecological indices to assess, for example the successional stage, disturbance level or nutrient status of the soil A different method of estimating niche width is calculating the realized niche width (RNW; the set of conditions a species occupies) rather than the fundamental niche width, using diversity metrics or multivariate techniques (Devictor et al, 2010; Futuyma & Moreno, 1988) This approach is not biased by the choice of measured variables or the availability and ease of collection of environmental data (Fridley, Vandermast, Kuppinger, Manthey, & Peet, 2007), problems that are often found when using resource‐based methods (see Gaston, Blackburn, & Lawton, 1997 for a review). We assess the effects of LUI on these four indices and hypothesize that with increasing LUI, there will be a decrease in the ICS, diversity and richness
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
