Change in Jeffrey pine needle weight, expressed using the exponential decay function fit to each plot over six years. Colored lines represent mean decay (k) parameter values for the granitic (blue) and metamorphic (red) sites, with dashed lines representing 95% confidence intervals. Solid black lines represent other published k values for litter in Western conifer species: (1) from Keane (2008) for Pinus ponderosa (1a), Pseudotsuga menziesii (1b), Abies amabilis (Douglas) James Forbes (1c) and Thuja plicata Donn ex D. Don (1d) in their respective forest types in western Montana, USA; (2) from Taylor et al. (1991) for Pinus contorta (2a) and Picea engelmanii Parry ex Engelm. (2b) in P. engelmanii forest in Alberta, Canada; (3) from Stohlgren (1988) for Pinus lambertiana Douglas (3a), Abies concolor (3b), and Calocedrus decurrens (Torr.) Florin (3c) in mixed-conifer forest of the Sierra Nevada; and (4) from Edmonds (1980) for Abies amabilis (4a) and Pseudotsuga menziesii (4b) in their respective forest types in western Washington, USA.