Data from: Species-specific effects of passive warming in an Antarctic moss system

Polar systems are experiencing rapid climate change and the high
sensitivity of these Arctic and Antarctic ecosystems make them especially
vulnerable to accelerated ecological transformation. In Antarctica,
warming regions result in a mosaic of ice-free terrestrial habitats
dominated by a diverse assemblage of cryptogamic plants (i.e. mosses and
lichens). Although these plants provide key habitat for a wide array of
microorganisms and invertebrates, we have little understanding of the
interaction between trophic levels in this terrestrial ecosystem, and
whether there are functional effects of plant species on higher trophic
levels that may alter with warming. Here, we used Open Top Chambers (OTCs)
on Fildes Peninsula, King George Island, Antarctica, to examine the
effects of passive warming and moss species on the abiotic environment and
ultimately on higher trophic levels. For the dominate mosses,
Polytrichastrum alpinum and Sanionia georgicouncinata, we found
species-specific effects on the abiotic environment, including moss canopy
temperature and soil moisture. Additionally, we found distinct
reproductive shifts in P. alpinum plants under warming compared to mosses
without warming, and invertebrate communities in this moss species were
strongly correlated with plant reproduction. Mosses under warming had
substantially larger total invertebrate communities, and some invertebrate
taxa were influenced differentially by moss species. However, warmed moss
plants showed lower fungal biomass than control moss plants, and fungal
biomass differed between moss species. Our results indicate that continued
warming will differentially impact the reproductive output of Antarctic
moss species, potentially altering terrestrial ecosystems dynamics from
the bottom up. Understanding these effects requires clarifying the
foundational, mechanistic role that individual plant species play in
mediating complex interactions in Antarctica’s terrestrial food-webs.