### 2.20.1.5. 14.1.5 Livewood Turnover[¶](#livewood-turnover "Permalink to this headline")

The conceptualization of live wood vs. dead wood fractions for stem and coarse root pools is intended to capture the difference in maintenance respiration rates between these two physiologically distinct tissue types. Unlike displayed pools for leaf and fine root, which are lost to litterfall, live wood cells reaching the end of their lifespan are retained as a part of the dead woody structure of stems and coarse roots. A mechanism is therefore included in the phenology routine to effect the transfer of live wood to dead wood pools, which also takes into account the different nitrogen concentrations typical of these tissue types.

A live wood turnover rate (\\({r}\_{lwt}\\), s\-1) is defined as

(2.20.37)[¶](#equation-20-37 "Permalink to this equation")\\\[r\_{lwt} ={p\_{lwt} \\mathord{\\left/ {\\vphantom {p\_{lwt} \\left(365\\cdot 86400\\right)}} \\right.} \\left(365\\cdot 86400\\right)}\\\]

where \\({p}\_{lwt} = 0.7\\) is the assumed annual live wood turnover fraction. Carbon fluxes from live to dead wood pools are:

(2.20.38)[¶](#equation-20-38 "Permalink to this equation")\\\[CF\_{livestem,deadstem} =CS\_{livestem} r\_{lwt}\\\]

(2.20.39)[¶](#equation-20-39 "Permalink to this equation")\\\[CF\_{livecroot,deadcroot} =CS\_{livecroot} r\_{lwt} ,\\\]

and the associated nitrogen fluxes, including retranslocation of nitrogen out of live wood during turnover, are:

(2.20.40)[¶](#equation-20-40 "Permalink to this equation")\\\[NF\_{livestem,deadstem} ={CF\_{livestem,deadstem} \\mathord{\\left/ {\\vphantom {CF\_{livestem,deadstem} CN\_{dw} }} \\right.} CN\_{dw} }\\\]

(2.20.41)[¶](#equation-20-41 "Permalink to this equation")\\\[NF\_{livestem,retrans} =\\left({CF\_{livestem,deadstem} \\mathord{\\left/ {\\vphantom {CF\_{livestem,deadstem} CN\_{lw} }} \\right.} CN\_{lw} } \\right)-NF\_{livestem,deadstem}\\\]

(2.20.42)[¶](#equation-20-42 "Permalink to this equation")\\\[NF\_{livecroot,deadcroot} ={CF\_{livecroot,deadcroot} \\mathord{\\left/ {\\vphantom {CF\_{livecroot,deadcroot} CN\_{dw} }} \\right.} CN\_{dw} }\\\]

(2.20.43)[¶](#equation-20-43 "Permalink to this equation")\\\[NF\_{livecroot,retrans} =\\left({CF\_{livecroot,deadcroot} \\mathord{\\left/ {\\vphantom {CF\_{livecroot,deadcroot} CN\_{lw} }} \\right.} CN\_{lw} } \\right)-NF\_{livecroot,deadcroot} .\\\]

