三峡库区乔木林生物量和碳储量的估算

以三峡库区为研究地点,建立库区优势树种立木生物量模型,并测定乔木含碳系数,结合库区第7次和第8次森林资源连续清查数据,估算了整个三峡库区乔木林的生物量和碳储量。研究结果表明:(1)整个库区乔木林生物量和碳储量第7次调查为12 583×104t和6 471×104t,单位面积生物量75.70t/hm2,碳密度38.93t/hm2,第8次调查为14 253×104t和7 396×104t,单位面积生物量77.46t/hm2,碳密度40.20t/hm2。可见,这5a中,三峡库区生物量和碳储量都有所增加。(2)对于不同森林植被类型来说,松类的生物量和碳储量都显著高于其他类型,分别占三峡库区生物量和碳储量的40%和50%。(3)三峡库区森林植被生物量和碳储量随龄级增大先增大后减少,在中龄林时达到最大,比较两次调查的生物量和碳储量,森林植被主要以幼林龄和中龄林占优。(4)两次调查显示三峡库区森林植被生物量和碳储量主要分布在天然林中,对于碳汇起到主要作用,同时,人工林所占的比例有所提高,其碳汇能力也逐步提高。

ESTIMATION OF FOREST BIOMASS AND CARBON STOCK IN THE THREE GORGES RESERVOIR REGION

We estimated the biomass and carbon stocks of trees in the entire Three Gorges Reservoir Region based on an establishment of national standing tree biomass model and carbon coefficient measurement and on the combination of the seventh and eighth continuous forest inventory data of this region.The results showed that:(1) The amounts of vegetation biomass and carbon stocks for the seventh survey were 12 583 million tons and 6 471 million tons,respectively.The biomass was 75.70 t/hm2 and carbon density was 38.93 t/hm2.The corresponding amounts for eighth survey were 14 253 million tons and 7 396 million tons,respectively.The biomass was 77.46 t/hm2 and carbon density was 40.20 t/hm2.In the past five years,the biomass and carbon storage in this area have increased and played an important role in carbon sequestration.(2) The vegetation biomass and carbon stocks of pine forests in the two surveys were both significantly higher than other stands,accounting for 40 ％ and 50％ of the total.(3) The biomass and carbon stocks increased first and then decreased with increasing forest age class and for the middle-aged forest,the biomass and carbon stocks reached the maximum.As a general,Young-aged and middle-aged forest dominated during these two surveys.(4)In this area,forest biomass and carbon stocks were mainly composed of natural forests,which played a major role in carbon sequestration.The proportion of plantations has however increased,followed by a gradually increasing ability of carbon sequestration.