Dynamics of carbon stocks in soils and detritus across chronosequences of different forest types in the Pacific Northwest, USA

• DOI: 10.1111/j.1365-2486.2004.00829.x
• Publication Date: 2004-09-17T13:44:13Z
• Authors: Osbert J. Sun; John Campbell; Beverly E. Law; Vernon Wolf
• Keywords: Soil carbon; Detritus; Coarse Woody Debris; Western Hemlock; Forest floor; Chronosequence

Abstract We investigated variation in carbon stock soils and detritus (forest floor woody debris) chronosequences that represent the range of forest types US Pacific Northwest. Stands age from <13 to >600 years. Soil carbon, a depth 100 cm, was highest coastal Sitka spruce/western hemlock forests (36±10 kg C m −2 ) lowest semiarid ponderosa pine (7±10 ). Forests distributed across Cascade Mountains had intermediate values between 10 25 . stocks were best described as linear function net primary productivity ( r 2 =0.52), annual precipitation =0.51), power mean residence time =0.67). The rates soil turnover recorded on mesic sites Douglas‐fir/western with lower wetter drier habitats, similar pattern site productivity. relative contribution total ecosystem decreased negative exponential stand value ∼35% 150 200 years types. These age‐dependent trends portioning biomass necromass not different among Model estimates storage based decomposition legacy accumulation following stand‐replacing disturbance showed reached an asymptote years, which has significant implications modeling dynamics temperate coniferous disturbance.