Below-Ground Net Primary Production (BNPP): Root Ingrowth Donuts

In 2005, root ingrowth donuts were established on the Sevilleta NWR to monitor below ground biomass under different conditions and to compare estimates of root production between root ingrowth donut and mini-rhizonton tube methods at four sites on the east side of the refuge. Soil and roots are collected from the "donuts" annually in late fall after the growing season, and structures are then re-established in situ for consecutive harvests for the following years. Each structure allows roots to be harvested at two depths (0-15 and 15-30cm) to estimate root production, or "below ground net primary productivity".They were co-located with previously established mini-rhizotron tubes with ten replicate structues in both burned (2003) and unburned mixed blue and black grama dominated grassland plots (10 burned, 10 unburned) near Deep Well, 20 replicates on nitrogen fertilization plots (10 fertilized, 10 control), and 10 replicates in a creosote dominated shrubland located at the Five Points Creosote Core site.