Paper Reviewed
Bothwell, L.D., Selmants, P.C., Giardina, C.P. and Litton, C.M. 2014. Leaf litter decomposition rates increase with rising mean annual temperature in Hawaiian tropical montane wet forests. PeerJ 2: 10.7717/peerj.685.

Bothwell et al. (2014) present the results of a leaf litter decomposition experiment they conducted across a well-constrained 5.2°C mean annual temperature (MAT) gradient that consisted of nine permanent plots of native-dominated tropical montane wet forests that spanned an elevation of 800 meters along the eastern slope of Hawaii's Mauna Kea Volcano, which study they conducted because, in their words, "many potentially confounding factors remain constant across this MAT gradient, such as dominant canopy tree species, disturbance history, soil water content, geological substrate and soil type," citing the confirmatory studies of Litton et al. (2011), Iwashita et al., (2013) and Selmants et al. (2014).

This work revealed, in the words of the four researchers, that there was (1) "no evidence of nitrogen (N) limitation to leaf litter decomposition across the MAT gradient," but that there was (2) "an overall trend of increased rates of N release from decomposing litter with rising MAT." And they say that "taken together, this evidence suggests that warming will increase rates of N cycling and availability in these forests," which conclusion they describe as "consistent with results from warming experiments across a wide range of forest and grassland ecosystems," as per the meta-analysis of Rustad et al. (2001).

Thus, it is no surprise that Bothwell et al. conclude the report of their work by declaring that "an increase in rates of nutrient release from decaying leaf litter with climate warming, as suggested by our results, could delay or even prevent the onset of progressive nutrient limitation of ecosystem carbon sequestration."

References
Iwashita, D.K., Loitton, C.M. and Giardina, C.P. 2013. Coarse woody debris carbon storage across a mean annual temperature gradient in tropical montane wet forest. Forest Ecology and Management 291: 336-343.

Litton, C.M., Giardina, C.P., Albano, H.K., Long, M.S. and Asner, G.P. 2011. The magnitude and variability of soil-surface CO2 efflux increase with mean annual temperature in Hawaiian tropical montane wet forests. Soil Biology and Biochemistry 43: 2315-2323.

Rustad, L.E., Campbell, J.L., Marion, G.M., Norby, R.J., Mitchell, M.J., Hartley, A.E., Cornelissen, J.H.C., Gurevitch, J. and GCTE-NEWS. 2001. A meta-analysis of the response of soil respiration, net nitrogen mineralization, and aboveground plant growth to experimental ecosystem warming. Oecologia 126: 543-562.

Selmants, P.C., Litton, C.M., Giardina, C.P. and Asner, G.P. 2014.Ecosystem carbon storage does not vary with mean annual temperature in Hawaiian tropical montane wet forests. Global Change Biology 20: 2927-2937.