Impact of nitrogen input from biosolids application on carbon sequestration in a Pinus radiata forest  

作　　者：Jianming Xue Mark O.Kimberley Russell B.McKinley 

机构地区：[1]Scion,PO Box 29237,Christchurch,8440,New Zealand [2]Retired(previously Scion),Rotorua,3010,New Zealand [3]Scion,Private Bag 3020,Rotorua,3046,New Zealand

出　　处：《Forest Ecosystems》2022年第2期213-221,共9页森林生态系统（英文版）

基　　金：The Ministry of Business,Innovation and Employment,New Zealand provided funding(contract no.C03X0902)for this research.

摘　　要：Background:Forest management practices(e.g.choice of stand density,fertilisation)are just as important in carbon(C)forestry as in other types of forestry and will affect the level of C sequestration and profitability.Because C stored in wood is approximately proportional to the product of its volume and density,it is necessary to account for both volume growth and wood density when assessing the effects of fertilisation on C sequestration in pine forests.Methods:The effects of nitrogen(N)input from biosolids application on forest C sequestration were quantified from an intensively monitored biosolids field trial in a Pinus radiata plantation on a sandy soil in New Zealand.The field trial tested the application of three biosolids rates:Control(no application),Standard(300 kg N⋅ha^(-1) applied every three years),and High(600 kg N⋅ha^(-1) applied every three years),across three levels of stand density:300,450,and 600 stems⋅ha^(-1).Carbon sequestration was estimated using the C-Change model from annual plot measurements of stand density,stem height and diameter,and annual breast height wood densities obtained from increment cores.Results:By age 24 years,N-fertilised trees had sequestered 40 t C⋅ha^(-1) more than unfertilised trees,an increase of 18%.Fertilisation increased stem volume by 23%but reduced stem wood density by 2.5%.Most of the increased C sequestration occurred between age 6 and age 17 years and the Standard rate gave the same increase in C sequestration as the High rate.On average,there was no significant difference in growth rate between fertilised and unfertilised trees after the 17th growth year,but the increased growth ceased earlier at higher stand densities,and later at lower stand densities.Conclusions:This study indicates that 2–3 applications of the Standard rate would have been sufficient to achieve the increased C sequestration,with an applied N to C conversion ratio of 43–65 kg C⋅kg^(-1) N.Our results highlight that N fertilisation will become more widespread under greenhouse g

关 键 词：Biosolids application Stand density and growth Wood density C sequestration 

分 类 号：S791.252[农业科学—林木遗传育种]