Relationships of leaf dark respiration to leaf nitrogen, specific leaf area and leaf life-span: a test across biomes and functional groups.

TLDR: The relationships between Rd and leaf traits observed in this study support the idea of a global set of predictable interrelationships between key leaf morphological, chemical and metabolic traits.

Abstract: Based on prior evidence of coordinated multiple leaf trait scaling, we hypothesized that variation among species in leaf dark respiration rate (Rd) should scale with variation in traits such as leaf nitrogen (N), leaf life-span, specific leaf area (SLA), and net photosynthetic capacity (/4max)- However, it is not known whether such scaling, if it exists, is similar among disparate biomes and plant functional types. We tested this idea by examining the interspecific relationships between Rd measured at a standard temperature and leaf life-span, N, SLA and ^max for 69 species from four functional groups (forbs, broad-leafed trees and shrubs, and needle-leafed coni- fers) in six biomes traversing the Americas: alpine tun- dra/subalpine forest, was positively related to area-based leaf N within functional groups and for all species pooled, but not when comparing among species within any site. At all sites, mass-based Rd (Rd.mass) de- creased sharply with increasing leaf life-span and was positively related to SLA and mass-based Amax and leaf