Accurate simulations of high‐latitude ecosystems are critical for confident Earth system model (ESM) projections of carbon cycle feedbacks to global climate change. Land surface model components of ESMs, including the E3SM Land Model (ELM), simulate vegetation growth and ecosystem responses to changing climate and atmospheric CO₂ concentrations by grouping heterogeneous vegetation into like sets of plant functional types (PFTs). Many such models represent high‐latitude vegetation using only two PFTs (shrub and grass), thereby missing the diversity of vegetation growth forms and functional traits in the Arctic. Here, we use field observations of biomass and leaf traits across a gradient of plant communities on the Seward Peninsula in northwest Alaska to replace the original ELM configuration for the first time with nine Arctic‐specific PFTs. The newly developed PFTs include: (1) nonvascular mosses and lichens, (2) deciduous and evergreen shrubs of various height classes, including an alder PFT, (3) graminoids, and (4) forbs. Improvements relative to the original model configuration included greater belowground biomass allocation, persistent fine roots and rhizomes of nonwoody plants, and better representation of variability in total plant biomass across sites with varying plant communities and depth to bedrock. Simulations through 2100 using the RCP8.5 climate scenario and constant PFT fractional areas showed alder‐dominated plant communities gaining more biomass and lichen‐dominated communities gaining less biomass compared to default PFTs. Our results highlight how representing the diversity of arctic vegetation and confronting models with measurements from varied plant communities improves the representation of arctic vegetation in terrestrial ecosystem models.

中文翻译：

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利用地上和地下实地观测资料将北极植物功能类型整合到陆地表面模型中

高纬度生态系统的准确模拟对于可靠的地球系统模型（ESM）预测碳循环对全球气候变化的反馈至关重要。ESM的地表模型组成部分，包括E3SM土地模型（ELM），可模拟植被生长和生态系统对气候和大气CO ₂变化的响应通过将异类植被分组为类似的植物功能类型（PFT）集来实现高浓度。许多这样的模型仅使用两个PFT（灌木和草丛）就代表了高纬度植被，因此缺少了北极地区植被生长形式和功能性状的多样性。在这里，我们使用阿拉斯加西北部苏厄德半岛上植物群落梯度上的生物量和叶片性状的野外观察，首次用九种特定于北极的PFT取代了原始的ELM配置。新开发的PFT包括：（1）无血管的苔藓和地衣；（2）各种高度等级的落叶和常绿灌木，包括al木PFT；（3）类动物类动物；和（4）前b。与原始模型配置相比的改进包括更大的地下生物量分配，非木本植物具有持久的细根和根茎，并且在具有不同植物群落和基岩深度的地点之间更好地表示了植物总生物量的变异性。通过使用RCP8.5气候情景和恒定PFT分数区域进行的2100年模拟显示，与默认PFT相比，al木为主的植物群落获得更多的生物量，而地衣为主的群落获得更少的生物量。我们的研究结果突出了如何利用来自不同植物群落的测量值来代表北极植被的多样性和对立的模型如何改善陆地生态系统模型中北极植被的表示。5气候情景和恒定的PFT分数区域显示，与默认PFT相比，al木为主的植物群落获得更多的生物量，而地衣为主的群落获得更少的生物量。我们的研究结果突出了如何利用来自不同植物群落的测量值来代表北极植被的多样性和对立的模型如何改善陆地生态系统模型中北极植被的表示。5气候情景和恒定的PFT分数区域显示，与默认PFT相比，al木为主的植物群落获得更多的生物量，而地衣为主的群落获得更少的生物量。我们的研究结果突出了如何利用来自不同植物群落的测量值来代表北极植被的多样性和对立的模型如何改善陆地生态系统模型中北极植被的表示。