Carbon,Nitrogen and Phosphorus Release and Their Stoichiometric Ratio Change During Decomposition of Cunninghamia lanceolata Leaf Litter at Different Temperatures
[Objective]To explore the effects of rising temperature on the release of carbon(C),nitrogen(N)and phosphorus(P)during leaf litter decomposition of Chinese fir at different developmental stages and their stoichiometric variations under the scenarios of climate warming.[Methods]The leaf litter of Chinese fir at three developmental stages,i.e.middle-aged forest(18-years old),mature forest(30-years old)and overmature forest(42-years old),was collected for decomposition experiments at three temperature treat-ments(i.e.,25,30 and 35℃).[Results](1)During the 264-day decomposition period,the residual rates of C,N and P in leaf litter at each development stage generally decreased over time.The residual rates of C,N and P showed patterns with release-enrichment-release,release-release,and release-enrichment,re-spectively.(2)The results of Olson fitting model revealed that the N turnover time of mature forest and over-mature forests during litter decomposition was shortened by 34.4 and 16.9%,respectively under 35℃compared with 25℃.In comparison,the P turnover time was shortened by 38.4%and 43.8%,respect-ively.(3)During litter decomposition,the ratios of C∶N and N∶P generally fluctuated,and C∶P in-creased first and then decreased.The variation of C∶N,C∶P and N∶P ratios were 9.32-39.0,949-2 194 and 32.7-153,respectively.In the decomposition process of leaf litter,rising temperature increased C∶P,N∶P,and decreased C∶N.[Conclusion]Rising temperature can shorten the turnover rate of N and P during litter decomposition in mature and overmature forests by increasing C∶P and N∶P ratios during lit-ter decomposition,indicating that litter decomposition of Chinese fir is obviously limited by P.It is sugges-ted to appropriately increase the application of P fertilizer according to the growth needs of Chinese fir at different developmental stages.
Chinese firdifferent developmental stagesleaf litterrising temperaturecarbon,nitrogen and phosphorusstoichiometric ratios
万方数据
维普
