BGPVC Plant species composition in the Belowground Plot Experiment at Konza Prairie

Two permanent plant composition plots were marked with conduit in each of the 64 plots. Canopy cover was recorded in a 5 m2circular area surrounding each of the plots.  At approximately 5-year intervals, coverage is assessed in late July, using visual estimates of cover by species, based on a modified Daubenmire scale. In 1989, sampling was done once in early July after mowing using one 10 m2 plot placed randomly in the approximate center of each plot. In 1994, plant composition sampling was done in early June in the unmowed plots; sampling in the mowed plots occurred in August. In 1999, two permanent conduits were placed in each plot, and sampling was conducted in June, before mowing, and again in August using 5 m2 plot sizes. In 2005 and afterward, sampling was reduced to one time in late July. Sampling occurred once every five years until 2015. Plots have been sampled annually since 2016. Two of the long-term unburned plots in a wildfire in 1994 and 1995. Those plots and years of the fire are indicated on the linked plot map. The mowing treatment was discontinued after 2002 due to invasion of the mowed plots by old world bluestem grasses. Data users should check for exotic species impacts on specific mowed subplots prior to this. In addition, fertilization in all plots ceased in 2017 as part of recovery from chronic N enrichment experiment.

64个样地中的每一个均布设了两根导管（conduit），用于标记永久植被组成样地。在每个样地周边的5平方米圆形区域内记录冠层盖度。每间隔约5年于7月下旬开展盖度评估，基于修正版多本迈尔（Daubenmire）盖度等级，通过目视估测各物种的盖度。1989年，刈割后于7月初开展一次采样，在每个样地的近似中心随机布设1个10平方米的样方。1994年，未刈割样地于6月初开展植被组成采样，刈割样地则于8月完成采样。1999年，每个样地均布设两根永久导管；于6月（刈割前）和8月开展两次采样，样方面积设为5平方米。2005年及之后，采样频次缩减为每年7月下旬1次；2015年前均保持每5年采样1次，自2016年起改为每年采样1次。1994年与1995年的野火波及其中2个长期未火烧样地，受影响样地及火灾年份已在关联样地图中标注。2002年后停止刈割处理，原因是刈割样地被旧世界须芒草（old world bluestem grasses）入侵。数据使用者需核查2002年之前，外来物种对特定刈割小样地的影响。此外，作为长期氮富集实验恢复措施的一部分，所有样地的施肥操作于2017年停止。