PTN01 Aboveground net primary productivity along transects spanning topographic gradients on an annually burned and unburned watershed at Konza Prairie

In 1989, single transects spanning upland-lowland-upland topographic positions were established in a long-term unburned (0020B) and an annually burned (001D) watershed. Standing crop biomass data were collected in late season at 11 sites along each transect and sorted into live graminoids, forbs and woody plants, current year's dead, and previous years dead vegetation. Four 0.1 m2 quadrats were harvested at each of the 11 sites per watershed and all data except previous years' dead were combined to provide an estimate of aboveground NPP. In 1993, soil moisture measurements began along each transect at 15 and 30 cm depths (where possible) with a Time Domain Reflectomerty (TDR) system. Measurements were made twice a month from March - October and intermittently during the winter months.1989年，研究人员在编号为0020B的长期未火烧流域与编号为001D的年度火烧流域中，分别布设了一条覆盖高地-低地-高地地形梯度的单样带。于生长季末期在每条样带的11个采样点采集群落现存生物量数据，并将其划分为活禾本科草本（graminoids）、杂类草（forbs）、木本植物、当年枯落物及前一年枯落物五类。每个流域的11个采样点均设置4个0.1平方米样方（quadrats）进行采样，除前一年枯落物外的所有数据被合并，用于估算地上净初级生产力（NPP）。1993年，研究人员借助时域反射仪（Time Domain Reflectometry, TDR）系统，在每条样带的15cm与30cm深度（可行采样区域）开展土壤湿度监测：3月至10月期间每月开展两次测量，冬季则进行间断性监测。