IAI-Data-CRN_012_Sala_PozosN: Aboveground and belowground nitrogen cycle in the Patagonian steppe

The general objective of this experiment was to describe the
aboveground and belowground nitrogen cycle in the Patagonian
steppe. We used the Patagonian steppe as a model ecosystem because of
the accumulated knowledge, and because of the spatial heterogeneity
characterized by a two-phase mosaic vegetation structure. We
considered four dimensions to construct the nitrogen budget,
aboveground species identity spatial heterogeneity of vegetation, soil
depth, and time. Our aim was to construct a spatial and temporal
nitrogen model.We sampled vegetation biomass of the Patagonian steppe
dominant species, by alive or dead categories along one year. We
collected biomass from dominant shrubs species (Mulinun spinosum,
Senecio filaginoides and Adesmia campestris) and dominant grasses
species (Stipa speciosa, Stipa humilis and Poa ligularis). Grass
biomass was collected in two micro sites a) ring-shrubs and b)
scattered tussock. Material was sorted in green, recently dead,
standing old dead, and litter. We sampled biomass from early spring to
early autumn. We sampled soil NO3 and NH4 below different micro sites,
different depth along one year. We considered the following
micro-sites: a) bare soil b) scattered tussocks grasses c) ring of
grasses around shrubs d) shrubs. We sampled at 5, 15, 30, 60 and 100cm
depth, five times from spring to early autumn. We had 10
replicates. These data were obtained for project CRN12 (The Role of
Biodiversity and Climate in the Functioning of Ecosystems: A
Comparative Study or Grasslands, Savannas, and Forests), which has
Dr. Osvaldo E. Sala as PI.