Determining the potential for soil carbon storage under different fire regimes in drylands

当干扰得到控制时，土壤可能包含大量的碳封存和减缓气候变化的能力。我的目标是通过在全球火灾实验网络中对潜在机制进行实验测试，开发基于过程的模型，并在活性碳信用市场中实施，来了解火灾管理如何在全球范围内影响土壤碳封存。管理火灾制度以促进土壤碳的固存可能是巨大的，因为每年有5%的火燃烧全球，燃烧的地区约占全球表土C的70%。这些全球火灾驱动的碳排放的75%以上发生在干旱的生态系统，如热带草原，那里的火灾主要是由规定的燃烧引起的，而不是在森林中观察到的无控制的野火，这为调整火灾管理以固碳提供了机会。我们将增进我们对火灾如何影响土壤C的理解，以了解气候、植物生产力和分解在调节火灾对土壤的影响方面的作用，以及如何管理火灾制度来最大限度地利用旱地的土壤碳储量。首先，我将系统地调查15个控制火灾频率30-65年的站点的生态系统C通量和储量。其次，我将建立一个C和N循环模型，并将模型输出与历史模型进行比较，以了解土壤稳定性的变化如何改变对土壤的火灾影响。最后，我将讨论基于自然的气候解决方案的应用主题，以量化在牧场改变的火灾管理方案下的潜在碳储量。重点将放在北美，因为模型需要长期和高分辨率的数据集，以及与运行碳信用购买计划的行业合作伙伴的持续合作。综合起来，这三个目标旨在实现一个高风险但高回报的目标，即在支持经济发展的同时减缓气候变化。

Soils may contain a vast capacity to sequester carbon and slow climate change when disturbances are managed. I aim to understandhow fire management can impact soil carbon sequestration at the global scale using experimental tests of underlying mechanismsacross a global network of fire experiments, development of process-based models, and implementation into an active carbon-creditmarketplace. Managing fire regimes to promote soil carbon (C) sequestration has the potential to be large, given that fire burns 5% ofthe globe annually and areas that burn account for ~70% of global topsoil C. More than 75% of these global fire-driven C emissionsoccurs in dryland ecosystems such as savannas, where fires are primarily caused by prescribed burns, not uncontrolled wildfiresobserved in forests, offering an opportunity to adjust fire management to sequester C.We will advance our understanding of how fire impacts soil C to understand the role of climate, plant productivity, anddecomposition in regulating fire effects on soils, and how fire regimes can be managed to maximize soil C storage in drylands. First, Iwill systematically survey ecosystem C fluxes and storage across 15 sites that have manipulated fire frequencies for 30-65 years.Second, I will develop a model of C and nitrogen cycling and compare model outputs with historical models to understand howchanges in soil stability modify fire effects on soils. Finally, I will address the applied topic of nature-based climate solutions toquantify potential C storage under altered fire management schemes in rangelands. The focus will be on North America because ofthe long-term and high-resolution datasets necessary for models and an ongoing collaboration with industry partners that runcarbon credit purchasing programs.Combined, the three objectives aim to achieve a high-risk but high-reward goal of slowing climate change while supportingeconomic development.