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.为探究火、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影响，1986年，作为康扎草原长期生态研究（Long-Term Ecological Research, LTER）计划的一部分，一项长期野外实验正式启动。本实验的总体目标包含两项：其一，记录植物与土壤在火、地上生物量移除（该小型样地中放牧的替代处理手段）以及养分添加（施加氮[N]和/或磷[P]）条件下的短期与长期响应；其二，深入解析高草草原对火、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个地下样地采集活体与枯亡草本根系的现存生物量样本，采样规格为0.1平方米×20厘米深度的土样。针对上述活体与枯亡草本根系，测定其氮与磷含量。部分年份的部分样地中，还可获取杂类草根系的氮、磷浓度数据。