Hypothesis
Standard isoprene emission algorithms, built from a few vascular plant species and widely applied to moorland, would reproduce isoprene fluxes from a moss-dominated peat bog.
What failed
Over six weeks of flux and enclosure measurements above a Scottish peat bog, the light response never saturated, and both big-leaf and canopy-level algorithms failed to match observed fluxes: they overestimated emissions below about 1000 μmol m⁻² s⁻¹ PAR and underestimated them on clear days.
Broken assumption
Light-response curves derived from vascular plants transfer to non-vascular, moss-dominated vegetation.
Why
The authors attribute the non-saturating response to the architecture of moss hummocks, which probably attenuate light differently from a grass canopy.
From the published paper: Langford et al. Environmental Research Ecology, 2022. ↗CC BY