Using the functional traits of soil fungi to improve post-disturbance pine regeneration

新的干扰制度威胁着支持省和国家经济的可靠的森林商品供应。连续的干扰，如野火，山地松甲虫（Dendroctonus ponderosae）爆发，和植物入侵的累积效应破坏了森林的再生能力和恢复到干扰前的条件。黑松（Pinus contorta）的再生尤其重要，因为这是加拿大西部的主要木材物种。经济问题和累积干扰的影响在未来几年可能会变得越来越明显，因为随着气候变化，黑松林的压力会增加，从而造成生物和非生物干扰之后是野火和物种入侵的条件。这些干扰造成的巨大压力可能超过林业维持可持续森林产品和服务的能力。因此，改进森林再生方法和技术对森林资源的长期可持续性至关重要。我们提出的研究调查了各种新的干扰方案如何改变再生树木从土壤真菌群落中获得的好处。树苗依靠土壤真菌释放有用的养分，增加养分吸收，增强对昆虫和病原体的抵抗力。然而，干扰会对土壤真菌群落产生不利影响，反过来，这些变化可能会改变幼苗从真菌中获得的益处，最终降低幼苗健康。本项目的目标是（1）确定土壤真菌群落如何受到一系列新的和累积的森林干扰的影响，（2）确定真菌群落的组成部分，促进森林更新后的干扰，和（3）确定干扰是否改变土壤真菌在森林更新中的功能作用。我们将结合联合收割机田间和温室实验，以确定管理措施，可以防止土壤真菌群落和森林生态系统崩溃的累积干扰。新的做法可包括土壤改良和场地准备建议。

Novel disturbance regimes threaten the dependable forest commodity supplies that bolster provincial and national economies. The cumulative effects of successive disturbances such as wildfires, mountain pine beetle (Dendroctonus ponderosae) outbreaks, and plant invasions undermine the ability of forests to regenerate and return to pre-disturbance conditions. Regeneration of lodgepole pine (Pinus contorta) is especially critical as this is a dominant timber species in western Canada. Economic concerns and impact of cumulative disturbances may become increasingly pronounced in coming years as stress in lodgepole pine forests increases with climate change, creating conditions where biotic and abiotic disturbances are followed by wildfire and species invasions. Substantial pressure from these disturbances may exceed the forest industry's capacity to maintain sustainable forest goods and services. Improving forest regeneration methods and technologies is therefore crucial to long-term sustainability of forest resources. Our proposed research investigates how various novel disturbance scenarios alter the benefits regenerating trees receive from soil fungal communities. Tree seedlings depend on soil fungi to release usable nutrients, increase nutrient uptake, and enhance resistance to insects and pathogens. However, disturbances can adversely affect soil fungal communities, and in turn these changes may alter the benefits seedlings receive from fungi, ultimately reducing seedling health. The goals of this proposed project are to (1) determine how soil fungal communities are affected by an array of novel and cumulative forest disturbances, (2) identify the components of fungal communities that promote regeneration following disturbance, and (3) determine whether disturbances alter the functional roles of soil fungi in forest regeneration. We will combine field and greenhouse experiments to identify management practices that can prevent cumulative disturbances from collapsing soil fungal communities and forest ecosystems. New practices could include soil amendment and site preparation recommendations.