Effects of Btk management of spruce budworm on soil carbon sequestration

云杉芽孢虫是北美东部最具破坏性的森林害虫，目前正在**暴发，魁北克的严重落叶正在蔓延到新不伦瑞克。目前控制云杉芽孢子虫的努力包括喷洒新型生物杀虫剂，主要目标有两个：保护树叶，使**森林继续生长以获得收获，以及阻止或限制芽孢子虫暴发的地理传播。**然而，芽孢子虫喷洒计划可能还有第三个好处：维持森林土壤中的碳储存**。土壤从树叶或针叶等有机物质中积累和释放碳，这样做与推动全球气候变化的大气二氧化碳池**有关。冷杉和云杉在虫害下的落叶在短期内可能会增加土壤中的有机质，从而加强碳的储存。从长远来看，树木生长和存活的减少可能会减少土壤中有机质的积累，树冠遮荫的丧失可能会使土壤变暖，从而增加土壤的碳释放速率。**了解控制芽孢子虫对土壤碳储存的短期和长期影响**对于喷洒计划的成本效益评估将是重要的**。

Spruce budworm is the most damaging forest pest in eastern North America, and is currently un-dergoing an**outbreak, with severe defoliation in Quebec spreading into New Brunswick. Current efforts to control spruce**budworm involve spraying with novel biological insecticides, with two primary goals: protecting tree foliage so**forests continue to grow for harvest, and arresting or limiting geographic spread of the budworm outbreak.**However, there may be a third benefit to budworm spray programs: maintenance of soil carbon storage in forest**soils. Soils accumulate and release carbon from organic matter such as leaf or needle litter, and in doing so are**linked to the atmospheric carbon dioxide pool that is driving global climate change. Defoliation of fir and**spruce trees under budworm attack might add organic matter to soils in the short term, enhancing carbon**storage. In the longer term, reduced tree growth and survival might reduce organic matter accumulation in**soils, and loss of shading from tree canopies may warm soils and thus increase their rate of carbon release.**Understanding the short- and longer-term effects of budworm control on soil carbon storage will be important**for cost-benefit assessment of spray programs.