FORMIT-M + EFDM + Yasso workflow for forest state modelling across Europe

This repository documents the models developed under the PathFinder project (WP3.2), specifically the subtask Forest Structure and Living Biomass Carbon, focusing on forest growth and management modelling for scenario analysis. A pan-European scenario based on RCP4.5 and SSP2 for the period 2020–2050 is provided to demonstrate the modelling workflow, which combines the process- and data-based hybrid forest simulator FORMIT-M, the European Forestry Dynamics Model (EFDM), and the soil carbon model Yasso. FORMIT-M simulates forest development at the plot level, accounting for climate change impacts via the maximum annual gross primary productivity (maxGPP) parameter, with pre-calculated maxGPP values corresponding to RCP2.6, RCP4.5, and RCP8.5 across Europe. EFDM is a transition matrix model that simulates forest area dynamics based on management activity probabilities and transition probabilities, parameterized using paired permanent National Forest Inventory (NFI) plot data and FORMIT-M outputs. EFDM activity probabilities at the 1 km² resolution were derived using present-day forest management intensity maps generated with the CLUMondo land-use model. Initial forest area distributions for 2020 were based on analysis of high-resolution (10 m²) satellite imagery and NFI data. Biodiversity indicator calculation, including species richness and the Shannon index, were incorporated into the EFDM simulations. Variation in forest structure and growth patterns across European continent is accounted for by using ten tree species groups and three sub-regions (i.e. North, Central, and South Europe). Yasso is soil carbon model, in which decomposition of various carbon input components is modelled as a function of climate, chemical composition, and the size of woody litter elements. EFDM scenario outputs were processed into Yasso model inputs following the completion of a full EFDM simulation. Pan-European EFDM scenario for the period of 2020-2050 was created following CLUMondo RCP45 + SSP2 forest management storyline. Documentation and the complete FORMIT-M - EFDM - Yasso framework code is provided for modelling future forest structure and living biomass carbon at a resolution of 1 km2 over Europe.

本仓库记录了PathFinder项目（WP3.2）下开发的相关模型，具体对应森林结构与活体生物量碳子任务，聚焦用于情景分析的森林生长与管理建模工作。本研究提供了一套基于RCP4.5与SSP2情景、覆盖2020至2050年的泛欧洲模拟场景，用于展示建模流程；该流程融合了基于过程与数据的混合森林模拟器FORMIT-M、欧洲林业动态模型（European Forestry Dynamics Model, EFDM）以及土壤碳模型Yasso。FORMIT-M在样地尺度上模拟森林发育过程，通过年总初级生产力最大值（maximum annual gross primary productivity, maxGPP）参数考量气候变化的影响，其预计算的maxGPP数值对应欧洲范围内RCP2.6、RCP4.5及RCP8.5三种情景。EFDM是一种转移矩阵模型，基于经营活动概率与转移概率模拟森林面积动态，其参数通过配对的永久性国家森林清查（National Forest Inventory, NFI）样地数据与FORMIT-M输出结果进行校准。分辨率为1平方千米的EFDM经营活动概率，通过CLUMondo土地利用模型生成的当前森林经营强度图谱推导得到。2020年的初始森林面积分布基于对高分辨率（10平方米）卫星影像与NFI数据的分析。生物多样性指标计算（包括物种丰富度与香农指数）已被纳入EFDM模拟流程。通过划分10个树种组与3个欧洲次区域（即北欧、中欧与南欧），考量欧洲大陆范围内森林结构与生长模式的差异。Yasso是一款土壤碳模型，其将各类碳输入组分的分解过程建模为气候、化学组成以及木质凋落物元素尺寸的函数。在完成完整的EFDM模拟后，EFDM情景输出将被处理为Yasso模型的输入数据。本次构建的2020至2050年泛欧洲EFDM情景，遵循CLUMondo模型的RCP4.5+SSP2森林管理情景设定。本仓库同时提供完整的建模文档与FORMIT-M-EFDM-Yasso框架代码，用于在1平方千米分辨率下模拟欧洲范围内的未来森林结构与活体生物量碳储量。