Litter quality and site characteristics interact to affect the response of priming effect to temperature in subtropical forests

1.Forest litter inputs to soil can stimulate the decomposition of older soil organic matter (SOM) via a priming effect (PE). The magnitude and underlying mechanisms driving PE are poorly understood, with especially little know about how litter quality and site conditions affect PE in situ. Further, very few studies have examined PE in tropical and subtropical soils.

2.Here, we established low and high elevation sites (600 vs 1400 m a.s.l.) in the subtropical Wuyishan National Park, China that differed with respect to mean annual temperature (MAT; ∆MAT = 4.2°C), vegetation, soil texture, and soil moisture. We conducted a one‐year field incubation study at these two sites to compare PE induced by adding low‐ and high‐quality 13C‐labelled leaf‐litter to soils.

3.At the low elevation site, additions of high‐quality (low C/N)litter caused a PE that was 140% greater than the PE observed following additions of low‐quality (high C/N) litter. In contrast, we saw no significant differences ...