Potential of forest fertilization to alleviate effects of climate change-induced insect infestation

由于气候引起的山松甲虫和西松甲虫的大规模爆发，到2013年，不列颠哥伦比亚省内陆大部分林业所依赖的松林将大部分消失。这将摧毁许多以森林为支柱的城镇的经济。作为增加木材供应的干预策略，不列颠哥伦比亚省森林和牧场部建议广泛使用施肥来加速现有林分的发展。考虑到去年不列颠哥伦比亚省1.7万公顷的土地进行了有效施肥，另外900万公顷的土地已经被松甲虫杀死，潜在的施肥面积非常大。早期在欧洲、美国东北部和阿拉斯加进行的研究表明，向森林中添加高水平的氮会减少根系生长，破坏微生物驱动的营养循环，并增加淋滤，但这种影响因生态系统而异，目前的理论无法预测。我们的研究很有用。在松林和云杉林内部进行了一项长期施肥试验，以测试地下微生物群落及其提供的生态系统服务是否受到林分水平施肥的破坏。我们将使用尖端的方法来确定施肥对(i) N， P， K， S和B的养分供应速率和（ii）凋落物和土壤有机质的化学组成的影响。然后，我们将使用生化、同位素和分子方法来确定微生物群落是否已经“适应”了这些新的条件，或者土壤细菌和真菌循环改变营养物质的能力是否已经受到损害。这将是加拿大首次将肥料引起的土壤有机质化学变化与森林土壤养分循环的相应变化联系起来。研究结果将使森林许可证持有者和政府监管机构能够确定肥料制度，以实现促进生长和生态系统恢复能力的最佳结合。

Due to the massive, climate-induced outbreak of the Mountain and Western Pine Beetles, the pine forests on which much of the forest industry in interior BC is based will largely disappear by 2013. This will devastate the economies of many forestry-supported towns and cities. As an intervention strategy to increase timber supply, the BC Ministry of Forests and Range has proposed widespread use of fertilization to accelerate the development of already-existing stands. Given that 17,000 ha were operationally fertilized in BC last year, and that a further 9 million ha have already been killed by pine beetles, the potential area for fertilization is extremely large. Earlier research in Europe, the NE USA, and Alaska has demonstrated that addition of high levels of nitrogen to forests can reduce root growth, disrupt microbially-driven nutrient cycles, and increase leaching, but that effects vary by ecosystem and are not predicted by current theory. Our study would make use. of an existing long-term fertilization experiment in interior pine and spruce forests to test whether belowground microbial communities and the ecosystem services they provide are disrupted by stand-level fertilization. We | will use cutting-edge approaches to determine the effect of fertilization on (i) nutrient supply rates of N, P, K, S, and B and (ii) chemical composition of litter and soil organic matter. We will then use biochemical, isotopic, and molecular methods to determine whether the microbial community has 'adapted' to these new conditions or whether the ability of soil bacteria and fungi to cycle the altered nutrients has been compromised. This will be the first time in Canada that fertilizer-induced changes in the chemistry of soil organic matter will be linked to corresponding changes in nutrient cycling in forest soils. The results will allow forest licensees and government regulators to identify fertilizer regimes that allow the best combination of growth enhancement and ecosystem resilience.