Towards developing the next generation of the carbon budget model of the Canadian forest sector (CBM-CFS) by including non-disturbance factors

CBM-CFS 3是目前的版本，用于估算加拿大管理下的森林碳预算，以便向《联合国气候变化框架公约》（《气候公约》）报告，并协助加拿大在科普气候变化的努力中制定森林管理备选方案。该模型以森林清查数据为基础，全面考虑到所有主要的碳循环组成部分。 该模型的核心是一组来自加拿大各地的库存和地块级森林生长和产量数据的体积年龄曲线。 这些曲线反映了过去森林生长的一般模式，但不能说明气候的年际变化，它们本身也不能对预测的未来气候和大气成分的变化作出反应。综合陆地生态系统碳模型（InTEC）利用粮安委研究人员汇编的森林年龄结构和干扰数据，采用基于过程的方法估算森林生长和所有其他主要碳循环组成部分。该模型的优势在于它整合了干扰（火灾，昆虫和收获）和非干扰（气候，CO2和氮沉降）对碳循环的影响。该模型的弱点可能是缺乏验证的关键曲线，定义净初级生产力（NPP）的年龄和影响干扰后的再生估计。建议的研究旨在改进CBM-CFS和InTEC模型，结合他们的优势，使两个模型更全面。 我们的首要任务是用InTEC的非干扰模块增强CBM-CFS 3的当前版本，以模拟气候变率的影响以及大气CO2和氮输入对未受干扰和再生森林的长期变化趋势。我们还将使用现有的动态植被模型来捕捉植被物种和结构对气候变化的潜在响应。这些支持下一代建立信任措施-粮安委（第4版）开发的新能力，将改进为报告目的对加拿大森林碳预算的估算，并提高支持加拿大森林部门气候减缓和适应战略政策分析的能力。

CBM-CFS3 is the current version used to estimate Canada's managed forest carbon budget for reporting to the United Nations Framework Convention on Climate Change (UNFCCC) and to assist in formulating forest management options in Canada's effort to cope with climate change. The model is based on forest inventory data with complete consideration of all major carbon cycle components. The core of the model is a set of volume-age curves derived from inventory and plot-level forest growth and yield data from across Canada. These curves capture the general pattern of past forest growth but do not account for interannual variations in climate nor can they, by themselves, respond to projected future changes in climate and atmospheric composition. The Integrated Terrestrial Ecosystem Carbon Model (InTEC) makes use of the forest age structure and disturbance data compiled by CFS researchers and estimates forest growth and all other major carbon cycle components using a process-based approach. The strength of this model lies in its integration of both disturbance (fire, insect and harvest) and non-disturbance (climate, C02 and nitrogen deposition) effects on the carbon cycle. The weakness of the model may be the lack of validation of the key curves that define net primary production (NPP) over age and affect regrowth estimation after disturbance. The proposed research aims at improving both CBM-CFS and InTEC models by combining their strengths and making both models more comprehensive. Our first priority will be to enhance the current version of CBM-CFS3 with a non-disturbance module from InTEC to simulate the effects of climate variability and the trends of long-term changes in atmospheric C02 and nitrogen inputs on undisturbed and regrowing forests. We will also use an existing dynamic vegetation model to capture potential responses of vegetation species and structure to climate change. These new capabilities in support the development of the next generation CBM-CFS (Version 4) will improve the estimation of Canada's forest carbon budget for reporting purposes and enhance the ability to support policy analyses of climate mitigation and adaptation strategies in the Canadian forest sector.