PBB03 Belowground Plot Experiment: Belowground plot experiment: biomass and nutrient content of Roots

To address the potential interactive effects of fire, aboveground biomass removal, and nutrient amendments on above- and belowground responses, a long-term field experiment was initiated in 1986 as part of the Konza Prairie Long-Term Ecological Research (LTER) program. The general goals of this experiment are: 1) to document both short- and long-term responses of plants and soils to fire, aboveground biomass removal (a surrogate for grazing in these small plots), and nutrient amendments (additions of N and/or P); and 2) to provide a better understanding of the mechanisms underlying tallgrass prairie responses to fire, aboveground biomass removal and nutrient enrichment. Standing crops of live and dead grass roots(0.1 sq. m2 x 20cm deep samples) are taken in late summer periodically from 64 belowground plots. N and P content are determined on live and dead grass roots. N and P concentrations for forb roots are available for some plots in some years.Â

为厘清火灾、地上生物量移除与养分添加对地上及地下生态过程的潜在交互效应，1986年依托康扎草原长期生态研究计划（Konza Prairie Long-Term Ecological Research, LTER）启动了该项长期野外定位实验。本实验的总体目标为：1）记录植物与土壤在火灾、地上生物量移除（小型样地中模拟放牧的替代手段）以及养分添加（施加氮[N]和/或磷[P]）作用下的短期与长期响应；2）深入解析高草草原对火灾、地上生物量移除及养分富集的响应机制。研究人员于每年夏末定期从64个地下样地中采集活禾草根与枯禾草根的生物量现存量样本（规格为0.1平方米×20厘米深度），并测定其中的氮（N）与磷（P）含量。部分年份的部分样地还提供了杂类草（forb）根系的氮、磷浓度数据。