Spatial mid-domain effect overrides climate, soil properties and
microbes on a cosmopolitan non-native plant across elevation
Abstract
Climate warming and anthropogenic activities have led to an increase in
the prevalence of non-native plants in mountainous regions that
previously exhibited limited occurrences. This phenomenon has resulted
in detrimental effects on endemic plants and ecosystem functions. Yet,
how traits of non-native plants that successfully spread to high
elevation vary along the elevation gradient, as well as the underlying
drivers of these changes, remain sparsely understood. In this study, we
use Erigeron annuus, a cosmopolitan non-native plant that has invaded to
high elevation, as our model to explore its individual biomass pattern
along a 1900 m elevation gradient. We also contrast this pattern with
the native Artemisia lavandulifolia, which has the same distribution
range as E. annuus. We found that the biomass of E. annuus displayed a
hump-shape pattern along elevation, while the biomass of native A.
lavandulifolia gradually decreased with elevation. By evaluating the
effect of climate variables, soil properties, rhizosphere fungal
communities and its spatial mid-domain effect (i.e. geographic
limitation) on plant biomass, we found that the biomass of E. annuus was
primarily influenced by the spatial mid-domain effect, while the biomass
of A. lavandulifolia resulted from a complex interplay of climatic
variables and rhizosphere microbial communities. Our findings emphasize
the importance of a spatial mid-domain effect on the growth of
non-native E. annuus along elevation, indicating the impact of E. annuus
probable be greatest at mid-elevations and thus, where management
priority should be set. Further investigations considering more
non-native plant species and species’ traits will allow to scrutinize
this vision.