Text by Lauri Laanisto
When gathering together publishing data from 2015, I found nearly a dozen papers co-authored by our lab members that had sneaked out under the blog´s radar. (And by blog´s radar I mean Google Scholar…) But now I´ve got them and I plan to do short posts about these during the upcoming weeks and get this lag settled with before the field season takes completely over.
The first of the overlooked papers – I approach them alphabetically – is written by Owen Atkin from Australia, and about 60 co-authors from all over the world. Including Ülo. It´s about leaf dark respiration, and assumedly most of the data came from TRY database, which is why Ülo ended up as one of the co-authors. This is how TRY works. Data was gathered for 899 species and the analytical part just associated leaf dark respiration with other pertinent leaf functional traits. In a typical macrophysiological fashion. Conclusions emphasize the variability of leaf dark respiration and “provide a framework for improving” stuff. Like models. It´s a solid building block for a path going towards global understanding of how vegetation works.
Full citation: Atkin, O. K., Bloomfield, K. J., Reich, P. B., Tjoelker, M. G., Asner, G. P., Bonal, D.,… Niinemets, Ü., … & Creek, D. (2015). Global variability in leaf respiration in relation to climate, plant functional types and leaf traits. New Phytologist, 206(2), 614-636. (link to full text)
- Leaf dark respiration (Rdark) is an important yet poorly quantified component of the global carbon cycle. Given this, we analyzed a new global database of Rdark and associated leaf traits.
- Data for 899 species were compiled from 100 sites (from the Arctic to the tropics). Several woody and nonwoody plant functional types (PFTs) were represented. Mixed-effects models were used to disentangle sources of variation in Rdark.
- Area-based Rdark at the prevailing average daily growth temperature (T) of each site increased only twofold from the Arctic to the tropics, despite a 20°C increase in growing T (8–28°C). By contrast, Rdark at a standard T (25°C, Rdark25) was threefold higher in the Arctic than in the tropics, and twofold higher at arid than at mesic sites. Species and PFTs at cold sites exhibited higher Rdark25 at a given photosynthetic capacity (Vcmax25) or leaf nitrogen concentration ([N]) than species at warmer sites. Rdark25 values at any given Vcmax25 or [N] were higher in herbs than in woody plants.
- The results highlight variation in Rdark among species and across global gradients in T and aridity. In addition to their ecological significance, the results provide a framework for improving representation of Rdark in terrestrial biosphere models (TBMs) and associated land-surface components of Earth system models (ESMs).