Biochar-based tree seed coatings for climate-smart forest restoration

有限的种子有效性（繁殖体限制）和育苗时的不利土壤条件是北方生态系统再造林的重要障碍。在偏远地区的大规模干扰中，用当地适应的遗传资源种树通常是不可行的，或者成本过高。从“气候智慧型林业”的角度来看，森林恢复和管理方面的这一长期挑战具有新的意义：即管理森林以增强森林恢复力和碳固存能力，并以其他方式减轻气候变化的影响。最近有证据表明，从木材废料中提取的热解有机物（“生物炭”）可以大大提高树木的性能，包括早期幼苗发育和随后的树木生长和存活。拟议的项目旨在开发和测试生物炭种子涂层，适用于加拿大偏远地区森林恢复的无人机精确播种方法。本研究的目标是：(1)在实验室和实地研究的基础上设计和测试生物炭基种子包衣，以评估替代生物炭、结合剂和包衣厚度对颗粒力学性能、种子萌发和早期发育以及对幼苗建立重要的土壤特性的影响；(2)评估用于种子包衣应用的替代生物炭原料，包括养分启动效应和“主场优势”假设的测试，即适应火的树种的树苗在同种原料的生物炭中表现最好；(3)在BC省北部和安大略省北部的目标恢复地点进行模拟和实际无人机散布替代类型生物炭种子涂层的现场试验，特别是包括大型火灾后和再生能力差的类似地点，并评估树木建立和碳封存结果。该项目旨在为工业合作伙伴BC Biocarbon和Seed The North， Inc.的新产品开发提供科学基础。

Limited seed availability (propagule limitation) and adverse soil conditions at the time of seedling establishment are important impediments to reforestation in northern ecosystems. In large-scale disturbances at remote sites tree planting with locally adapted genetic stock is commonly infeasible or prohibitively expensive. This long-standing challenge in forest restoration and management has taken on new significance from the perspective of "climate-smart forestry": i.e., managing forests to enhance forest resilience and carbon sequestration, and to otherwise mitigate climate change effects. There is recent evidence that pyrolyzed organic matter derived from wood waste material ("biochar") can substantially enhance tree performance, including early seedling development and subsequent tree growth and survivorship. The proposed project seeks to develop and test biochar seed coatings suitable for use in drone-based precision seeding approaches for forest restoration in remote sites in Canada. The proposed objectives of this research are to: (1) Design and test of biochar-based seed coatings based on lab and field studies that will assess effects of alternative biochars, binding agents, and coating thickness on granule mechanical properties, seed germination and early development, and on soil properties important to seedling establishment; (2) Evaluate alternative biochar feedstocks for seed coating applications, including tests of nutrient priming effects and of the "home-field advantage" hypothesis that tree seedlings of fire-adapted species will perform best in biochars from conspecific feedstock; (3) Conduct field trials of simulated and actual drone dispersal of alternative types of biochar seed coatings at sites in Northern BC and Northern Ontario representative of target restoration sites, specifically including large post-fire and similar sites with poor regeneration, and assess results in terms of tree establishment and carbon sequestration outcomes. The project is designed to provide a scientific foundation for new product development by the industrial partners BC Biocarbon and Seed the North, Inc.