Nitrogen-fixing bacterial community composition of agroecosystem biocrusts

Biocrusts, communities of microorganisms within the top centimeter of soil, are common in natural ecosystems. Although biocrusts in agroecosystems can have similar rates of nitrogen (N) fixation as those in natural ecosystems, it is unclear how agricultural management practices influence biocrust community composition and function. This study examined the bacterial and diazotrophic communities of biocrusts adjacent to crops in a citrus orchard and a vineyard that shared similar climate and soil type but differed in management. To contrast climate and soil type, these biocrusts were also compared to those from an apple orchard.

生物皮层，即土壤表层厘米范围内的微生物群落，在自然生态系统中普遍存在。尽管农业生态系统中的生物皮层在氮（N）固定速率上可能与自然生态系统相似，但农业管理实践对生物皮层群落组成和功能的影响尚不明确。本研究考察了位于柑橘果园和葡萄园附近的生物皮层中的细菌和固氮微生物群落，这两个果园在气候和土壤类型上相似，但在管理方式上存在差异。为了对比气候和土壤类型，这些生物皮层还与苹果园的生物皮层进行了比较。