This dataset is about the above ground biomass of submerged aquatic macrophytes (SAMs) collected in 2011 and 2012 from the East Fork Jemez River in the Valles Caldera National Preserve, NM before and after the Las Conchas fire.
To quantify the production of each species, we calculated the aboveground organic biomass using a standard ash free dry mass (AFDM) procedure. Samples were taken on transects within the ungulate exclosure and were collected approximately every six weeks during each growing season (May-October) to reduce possible cumulative impacts from sampling to the ecosystem. A sampling device for collecting all of the aboveground plant tissues in a known surface area was created for shallow flowing water use based on the Marshall and Lee (1994) basic design. Samples were preserved on ice and transported to the BioAnnex Analytical Laboratories at the University of New Mexico, Albuquerque, NM, USA for analysis. Upon return to the lab, the plant tissue samples were manually separated, and vegetation samples were sorted by taxa. Each individual sample was then sonicated in an ultrasonic water bath filled with deionized water for at least 10 minutes to remove epiphytic organisms. After sonication, each sample was placed in a drying oven at 60oC for 48 hours, then weighed. Approximately 250 mg subsamples were retained from the dried samples and stored in 20 mL glass scintillation vials for later carbon, nitrogen, and phosphorus content analysis. The remaining plant tissue was then fired in a muffle furnace at 500oC for two hours. The AFDM was then calculated and corrected for the removal of the subsample taken for elemental analysis.