Characteristics of Soil Carbon,Nitrogen,Phosphorus and Easily Oxidized Organic Carbon in Eucalyptus Plantations with Different Ages in Leizhou Peninsula
To investigate the impact of stand age on soil nutrient content carbon(C),nitrogen(N),phosphorus(P),etc.,and readily oxidizable carbon(ROC)in Eucalyptus plantations,we analyzed the eco-logical stoichiometry and C stability of soils at different depths in two Eucalyptus urophylla plantations(7 years and 12 years old)in the Leizhou Peninsula.Soil samples were collected at five layers,0-10 cm,10-20 cm,20-40 cm,40-60 cm,and 60-100 cm,for analyzing soil nutrient content and organic C.The results showed that:(1)ROC,total organic C(TOC),total N(TN),and total P(TP)of Eucalyptus urophylla planta-tion with 12 a were 72.64%,114.07%,225.69%,and 14.41%higher than those with 7 a,respectively,in-dicating that the soil TOC content and nutrient concentration of E.urophylla plantation increased with the in-crease of stand age.(2)The ROC/TOC of the surface soil(0-10 cm)of E.urophylla plantation with 12 a was significantly higher than that with 7 a(P＜0.05),indicating that the soil C stability of 12 a plantation was lower,while the ROC/TOC of the bottom soil(20-60 cm)of E.urophylla with 12 a was 36.85%lower than that with 7 a,suggesting that the C stability of 12 a was higher than that of 7 a.(3)The correlation analysis showed that there was a significant positive correlation between soil TOC and TN,available P(AP),C/P in two plantations,and the soil TOC of 7 a and 12 a plantations was also significantly affected by TP and N/P;re-spectively.Soil ROC showed a significant positive correlation with TN and C/P,and 7 a and 12 a plantations were also significantly affected by TP,AP and N/P,respectively,indicating that the TOC content and C sta-bility of 7 a were more affected by the supply of soil P elements.In addition,soil ROC/TOC of 12 a plantation was significantly affected by TN and N/P.The results show that the TOC content and C stability of 12 a were more easily regulated by soil TN content.Therefore,appropriately extending the rotation cycle of Eucalyptus plantations and improving the soil N and P supply levels according to different stand ages are conducive to impro-ving the soil C sequestration potential of Eucalyptus plantations in the Leizhou Peninsula.
NETL
NSTL
万方数据
