Abstract
The genus Pinus encompasses c 120 species and has a global distribution. Today we know more about the decomposition of pine needle litter than litter from any other genus. This paper presents a developed conceptual three-phase model for decomposition, based on pine needle litter, starting with newly shed litter and following the process until a humus-near stable residue. The paper focuses on the mass-loss dynamics and factors regulating the process in the early phase, the late one, and the humus-near phase. For the late phase, the hampering influence of N and the rate-enhancing effect of Mn on the decomposition are given extra attention. Empirical factors related to the limit value/stable residue are discussed as well as the decomposition patterns and functions for calculating limit values. The climate-related litter concentrations of N and Mn are discussed as well as their possible influence on the size of the stable residue, which may accumulate and sequester carbon, for example, in humus layers. The sequestration of carbon in humus layers is discussed as well as the effect of tree species on the process. Although the paper focuses on litter of pine species, there are comparisons to studies on other litter genera and similarities and differences are discussed.
Highlights
The process “plant litter decomposition” is quantitatively as large as the photosynthesis
With the massive information in the data base from the Long-term Intersite Decomposition Experiment Team (LIDET) confirming that decomposing foliar litter leaves a stable residue [16, 17] we may expect that the focus of interest for decomposition studies may change to be more directed towards (i) explaining the retardation of the decomposition process, (ii) developing the concept limit value that defines the stable fraction, and (iii) explaining the stability of the residue
Limit Value is the calculated value for the extent of decomposition of a given litter type, at which the decomposition rate approaches zero.Limit value may be given as accumulated mass loss (%) or as a fraction
Summary
The process “plant litter decomposition” is quantitatively as large as the photosynthesis. To create a first comprehensive image of the decomposition process as such, we may need to create at least a conceptual model, ideally based on one litter species or one genus Such a model should include influences of litter nutrients and organic components as well as rate-regulating factors and the litter’s contribution to accumulation of soil organic carbon. With the massive information in the data base from the Long-term Intersite Decomposition Experiment Team (LIDET) confirming that decomposing foliar litter leaves a stable residue [16, 17] we may expect that the focus of interest for decomposition studies may change to be more directed towards (i) explaining the retardation of the decomposition process, (ii) developing the concept limit value that defines the stable fraction, and (iii) explaining the stability of the residue. I repeatedly quote the DELILA database (DELILA II and DELILA III; http://www.eko.uj.edu.pl/deco/)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
