Analysis Of Carbon Sink Potential Of Four Plantation Forests In Rocky Desertification Region Of Western Hunan

Due to the unreasonable development and utilization of human beings and the fragility of the ecosystem in rocky desertification areas,forest vegetation disappears and carbon loss is very serious.The restoration of arbor forest vegetation in the comprehensive management of rocky desertification is also a carbon sink process.Therefore,rocky desertification areas have huge carbon sink potential..In this paper,the typical afforestation tree species Toona sinensis,Choerospondias axillaris,Cupressus lusitanica and Taiwania cryptomerioides in the rocky desertification area of western Hunan are used as the research objects.The standard trees were selected for trunk analysis,sampling of various parts of the standard trees,excavation of the underground root system to carry out root growth investigation and indoor biomass measurement experiments.To compare the growth,biomass and carbon storage of different tree species plantations,and to analyze the four types of plantations,the carbon sink potential provides a basis for the selection of the best carbon sink tree species in rocky desertification areas,thereby promoting economic development and ecological development in rocky desertification areas.The results show that:（1）The growth laws of the four standard trees are:diameter at breast height,tree height,and volume all increase with the increase of tree age,and the growth curve tends to be flat after entering the mature stage.（2）Comparing the biomass proportion of each organ of the four standard woods,the results show that:The four standard woods account for the largest proportion of trunk（bark）biomass,Toona sinensis and Choerospondias axillaris account for more root biomass than branches（leaves）,While Cupressus lusitanica and Taiwania cryptomerioides account for less root biomass than branches（leaves）.（3）The results of comparing the biomass and carbon storage of the four plantations show that:the biomass and carbon storage of the four plantations mainly come from the biomass and carbon storage of the arbor layer;The order of biomass in plantation is Cupressus lusitanica(186.41 t·hm^-2)>Toona sinensis(150.83 t·hm^-2)>Taiwania cryptomerioides(144.05 t·hm^-2)>Choerospondias axillaris(138.96 t·hm^-2);While the order of carbon storage in plantation is Cupressus lusitanica(94.85 t·hm^-2)>Taiwania cryptomerioides(76.48 t·hm^-2)>Toona sinensis(70.17 t·hm^-2)>Choerospondias axillaris(64.42 t·hm^-2).（4）The carbon sink capacity of the four standard trees is as follows:the carbon sink capacity increases with the increase of tree age,but when the carbon sink capacity reaches the peak,the carbon sink capacity gradually weakens.Toona sinensis,Choerospondias axillaris,and Taiwania cryptomerioides standard wood have the strongest carbon sink capacity at 40 a,27 a,and 35 a,respectively.While Cupressus lusitanica standard wood has the strongest carbon sink capacity due to limited conditions,which needs further study.（5）By comprehensively comparing the growth,biomass and carbon storage data of the four tree species and stand growth,analyzing the carbon sink potential of the four plantations in the rocky desertification region of western Hunan,the results show that:Cupressus lusitanica>Taiwania cryptomerioides>Toona sinensis>Choerospondias axillaris.Therefore,in the rocky desertification area of western Hunan,the best carbon sink tree species is selected,Cupressus lusitanica is preferred for conifers,and Toona sinensis is preferred for broad-leaved trees.