Coloration and phenology manifest nutrient variability in senesced leaves of 46 temperate deciduous woody species

Abstract

Abstract Aims Senesced-leaf nutrient concentrations vary significantly among co-existing plant species reflecting different leaf nutrient use strategies. However, interspecific variation in senesced-leaf nutrients and its driving factors are not well understood. Here, we aimed to determine interspecific variation and its driving factors in senesced-leaf nutrients. Methods We explored interspecific variation in carbon (C), nitrogen (N) and phosphorus (P) concentrations in newly-fallen leaves of 46 coexisting temperate deciduous woody species across the Maoershan Forest Ecosystem Research Station, Northeast China. The relative importance of ten biotic factors (i.e., mycorrhiza type, N-fixing type, growth form, shade tolerance, laminar texture, coloring degree, coloring type, peak leaf-coloration date, peak leaf-fall date, and end leaf-fall date) was quantified with the random forest model. Important Findings N and P concentrations varied four-fold and nine-fold among species, respectively. The high mean N (15.38 mg g -1) and P (1.24 mg g -1) concentrations suggested a weak N and P limitation in the studied forest. Functional groups had only significant effects on specific nutrients and their ratios. P concentration and N:P were negatively correlated with peak and end leaf-fall dates for the ectomycorrhiza species group. Brighter-colored leaves (red > brown > yellow > yellow-green > green) tended to have lower N and P concentrations and higher C:N and C:P than darker-colored leaves. The random forest model showed that autumn coloration and leaf-fall phenology contributed 80% to the total explanation of nutrient variability among species. The results increase our understanding of the variability in senesced-leaf nutrients as a strategy of woody plant nutrition in temperate forests.