Tropical forests are a critical component of the Earth system, storing half of the global forest carbon stocks and accounting for a third of terrestrial photosynthesis. Lianas are structural parasites that can substantially reduce the carbon sequestration capacity of these forests. Simulations of this peculiar growth form have only recently started and a single vegetation model included lianas so far. In this work we present a new liana implementation within the individual based model Formind. Initial tests indicate high structural realism both horizontal and vertical. In particular, we benchmarked the model against empirical observations of size distribution, mean liana cluster size and vertical leaf distribution for the Paracou site in French Guiana. Our model predicted a reduction of above-ground biomass between 10% for mature stands to 45% for secondary plots upon inclusion of lianas in the simulations. The reduced biomass was the result of a lower productivity due to a combination of lower tree photosynthesis and high liana respiration. We evaluated structural metrics (LAI, basal area, mean tree-height) and carbon fluxes (GPP, respiration) by comparing simulations with and without lianas. At the equilibrium, liana productivity was 1.9tC ha−1 y−1, or 23% of the total GPP and the forest carbon stocks were between 5% and 11% lower in simulations with lianas. We also highlight the main strengths and limitations of this new approach and propose new field measurements to further the understanding of liana ecology in a modelling framework.

中文翻译：

---

硅片中的藤本植物，来自结构寄生模型的生态学见解

热带森林是地球系统的重要组成部分，储存着全球森林碳储量的一半，占陆地光合作用的三分之一。藤本植物是结构性寄生虫，可显着降低这些森林的固碳能力。对这种特殊生长形式的模拟最近才开始，迄今为止一个单一的植被模型包括藤本植物。在这项工作中，我们在基于个体的模型 Formind 中提出了一个新的藤本植物实现。初步测试表明水平和垂直结构都具有高度的真实感。特别是，我们根据法属圭亚那帕拉库遗址的大小分布、平均藤本植物簇大小和垂直叶分布的经验观察对模型进行了基准测试。我们的模型预测，在模拟中加入藤本植物后，成熟林分的地上生物量减少 10% 至次生地块的 45%。生物量减少是由于树木光合作用较低和藤本植物呼吸作用较高而导致生产力较低的结果。我们通过比较有和没有藤本植物的模拟来评估结构指标（LAI、基面积、平均树高）和碳通量（GPP、呼吸）。在平衡时，藤本植物的生产力为 1.9tC ha-1 y-1，或总 GPP 的 23%，在藤本植物的模拟中，森林碳储量降低了 5% 至 11%。我们还强调了这种新方法的主要优势和局限性，并提出了新的实地测量，以在建模框架中进一步了解藤本植物生态学。