Data associated with: Drought response of trees: Differences across Mycorrhizal type at the global scale

The association with mycorrhizal fungi, predominantly arbuscular
mycorrhizal (AM) fungi or ectomycorrhizal (EM) fungi, is a critical
strategy for trees to cope with drought stress, one of the most pervasive
stressors affecting forest dynamics. Although experimental evidence
suggests varying drought responses among trees with different mycorrhizal
associations, a quantitative large-scale synthesis is still lacking. In
this study, we compiled global datasets encompassing three types of
drought responses (drought-induced mortality, growth reduction by severe
droughts, and growth recovery from severe droughts) and tested the
differences in these drought responses between the two mycorrhizal types
using spatial autoregressive models. To elucidate the significant
variations in drought responses, we identified key influential climatic
factors, edaphic (soil-related) factors, and species-specific traits using
model selection based on Akaike information criterion. Globally, EM trees
experienced slightly greater drought-induced mortality compared to AM
trees but showed significantly less pronounced growth reduction and
recovery following severe droughts. The drought responses of EM trees were
more strongly influenced by environmental stresses and size-related traits
than those of AM trees, with higher soil pH, greater climate seasonality,
and lower plant height significantly increasing the drought responses of
EM trees. Despite the above-mentioned apparent differences, drought
responses were generally more drastic at warmer and drier sites for
species producing heavier seeds regardless of mycorrhizal type.