Leaf litter chemistry controls on decomposition of Pacific Northwest trees and woody shrubs

Abstract

The effects of initial leaf litter chemistry on first-year decomposition rates were studied for 16 common Pacific Northwest conifers, hardwoods, and shrubs at the H.J. Andrews Experimental Forest in western Oregon. Leaf litters were analyzed for C, N, P, K, Ca, Mg, proximate organic fractions (nonpolar, polar, acid-hydrolyzable extractives, acid-hydrolyzable lignin, and acid-unhydrolyzable residue, previously termed "Klason lignin"), and biochemical components (total phenolics, reactive polyphenols, water-soluble carbohydrates, water-soluble proanthocyanidins, and water- and acid-unhydrolyzable proanthocyanidins). By including measurements of reactive and residual phenolic fractions and acid-hydrolyzable lignin, these analytical methods improve upon traditional proximate leaf litter analyses. Significant differences in litter chemistries and decomposition rates were found between species. For all species combined, the 1-year decay rate (k) values had highly significant correlations (P < 0.001) with 30 out of the 36 initial chemistry variables tested in this study. The three highest correlations were with acid-unhydrolyzable proanthocyanidins, lignocellulose index, and acid-unhydrolyzable residue (r = 0.83, –0.81, –0.80, respectively, with P < 0.0001 and n = 339). We found that no single litter chemistry variable was a universal predictor of the 1-year k value for each of the individual 16 species studied, though phenolic components were more frequent significant (P < 0.001) predictors of decomposition rate.

Optimization Forest Thinning Measures for Carbon Budget in a Mixed Pine-Oak Stand of the Qingling Mountains, China: A Case Study

“…Table 6 is as same as in Table 1. Biological characteristics of tree species might lead to varieties of chemical compound groups of litter [38]. Soil CO2 efflux results from chemical compound groups of litter transforming into different soil carbon compartments [13].…”

The Role of Quantitative Traits of Leaf Litter on Decomposition and Nutrient Cycling of the Forest Ecosystems

“…They concluded that leaf litter tannins play a key role in decomposition and nutrient cycling in the tropical rainforest. Leaves with high initial contents of condensed tannins, seem to decompose slowly in both terrestrial (Valachovic et al 2004) and aquatic ecosystems (Wantzen et al 2002). Condensed tannin may play an important role in aquatic leaf litter decomposition, as they may deter invertebrate shredders (Wantzen et al 2002).…”

Seasonal Pattern of Decomposition and N, P, and C Dynamics in Leaf litter in a Mongolian Oak Forest and a Korean Pine Plantation

“…Various factors control leaf litter decomposition, including climate [2], topography [3,4], chemical characteristics of leaf litter [5,6], and terrestrial microbiota [7]. Among those factors, climate, especially temperature and precipitation, is a dominant factor determining leaf litter decomposition patterns in regions experiencing distinct seasonal climate change [8].…”

“…In temperate natural forests, plant leaf litter usually decomposes in a mixed-species environment. Mixedwood forests are characterized by diverse soil conditions and biological activity within short distances, increasing the importance of small-spatial-scale research on soil nutrient pools, as well as integrating diverse chemical variables of single or mixed species into different temporal and spatial scales [6,11]. However, species composition is one of the factors most altered by human activities as natural mixedwood forests have been converted to single-species plantations.…”