Soil and climatic drivers of plant SLA (specific leaf area)

Global quantification of the relationship between plant SLA (specific leaf area) and climate and soil factors, reflects the trade-off between plant growth and environment. The power of soils and climate in predicting SLA is assessed in multivariate analyses and is compared to the distribution of growth forms across gradients of soil and climate factors. Data on SLA were collected for 3703 species distributed (13671 records), together with geographic, climate and soil information from each study site. Individual and combined effects of soils and climate on SLA were quantified using variance decomposition methods. We found leaf SLA of different life forms showed differences, among which shrub plants had relatively high SLA. This variation in SLA was positively correlated with latitude. The difference of leaf SLA is mainly affected by soil factors and climate factors also play an irreplaceable role. SLA was strongly correlated with soil PH and soil C:N. Soil is more important than climate in shaping latitudinal variation in plant SLA. The best model for the prediction of variation in SLA of all plants included soil PH, AP(annual precipitation) and their two-way interaction.