Older lineages of oribatid mites in mountain ranges have broader geographic ranges and exhibit more generalistic traits

Understanding ecological and evolutionary mechanisms that drive
biodiversity patterns is important for comprehending biodiversity. Despite
being critically important to the functioning of ecosystems, the
mechanisms driving belowground biodiversity are little understood. We here
investigated the radiation and trait diversity of soil oribatid mites from
two mountain ranges, i.e. the Alps in Austria and Changbai Mountain in
China, at similar latitude in the temperate zone differing in formation
processes (orogenesis) and exposed to different climates. We collected and
sequenced soil oribatid mites from forests at 950 to 1700 m at each
mountain and embedded them into the chronogram of species from temperate
Eurasia. We investigated the phylogenetic age of oribatid mites and
compared the node age of species with the mountain uplift time of the Alps
and Changbai Mountain. We then inspected trophic variation, geographical
range size and reproductive mode, and identified traits that promote
oribatid mite survival and evolution in montane forest ecosystems. We
found that oribatid mites on Changbai Mountain are phylogenetically older
than species in the Alps. All species on Changbai Mountain evolved long
before the uplift of Changbai Mountain, but some species in the Alps
evolved after the orogenesis of the Alps. On Changbai Mountain more
species possess broader trophic variation, have larger geographical range
sizes and more often reproduce via parthenogenesis compared to species
from the Alps. Species on Changbai Mountain survived the mountain uplift
or colonized the mountain thereafter supporting the view that generalistic
traits promote survival and evolution in phylogenetically old soil animal
species. Collectively, our findings highlight that combining species
traits and phylogeny allow deeper insight into the evolutionary forces
shaping soil biodiversity in montane ecosystems.