Estimation of the net primary productivity of forests on age in China

Abstract

Abstract. Under the background of global change, the internal relationship between forests' age and forests' carbon cycling is very important to study the position and function of forests in the global carbon cycle.Thus, the study employed field observations to inversely estimate the parameter of maximum light-use efficiency(ε max ) of forests in different stand ages, generated a national map of forests' NPP on forests age.We found the ε max has decreased with the increased of forest ages that is consistent with other studies, and compared with the fixed ε max , the NPP of forests was calculated on forests age are more reliable and stable.The results shows a significant heterogeneity of forests' NPP_age, and the average NPP of the evergreen broadleaf forest, the deciduous broadleaf forest, evergreen needleleaf forest and deciduous needleleaf forests is about 377.34, 293.99,273.63 and 306.36