Boreal Forest Agriculture

Climate change has expanded the northern boundaries of food production; however, a comprehensive understanding of how land conversion to agriculture in these regions will alter soil microbial communities and their biogeochemical cycling functions is currently incomplete and poorly understood. Understanding how soil microbial systems are altered by land conversion at different stages post-conversion provides information on how best to manage these expanding agricultural regions in a way that is sustainable at both the local level (e.g., enhanced fertility) and within a global context (e.g., reduced C and N losses). In this study, we investigated the soil microbiome at the current northern boundary of agriculture in Ontario Canada, using paired sites to compare baseline mature forest conditions with those of adjacent fields converted from forest to agriculture <10 years ago, >10 years ago but <50 years ago, and >50 years ago. Our objective was to evaluate post-land conversion changes in microbial functional potential, diversity, and community composition in a chronosequence according to time since conversion.

气候变化已拓展了粮食生产的北界，但目前学界对这些区域的土地转为农业用地后，将如何改变土壤微生物群落及其生物地球化学循环（biogeochemical cycling）功能的认知仍不全面、尚不透彻。明确土地转化后不同阶段土壤微生物系统的变化规律，可为这些不断扩张的农业区域制定最优管理策略提供依据，实现本地层面（如提升土壤肥力）与全球层面（如减少碳、氮流失）的可持续发展。本研究以加拿大安大略省（Ontario）当前的农业北界为研究区域，采用配对样地设计，对比原生成熟森林的基准状态，与相邻的、分别于10年以内、10至50年以前、50年以前由森林转为农业用地的地块的土壤微生物组（soil microbiome）特征。本研究旨在依据土地转化后的时间跨度，评估该时间序列样地中微生物的功能潜力、多样性及群落组成的转化后变化。