Soil nutrient fluxes and hot spots in a Mediterranean mixed-conifer forest

We evaluated the spatial and temporal patterns in nutrient HSs in two
mixed-conifer forest soils at the Southern Sierra Critical Zone
Observatory. The study area is located on the western slope of the
southern Sierra Nevada, California, USA. This region experiences a
Mediterranean-type climate where mean annual air temperature is 9.8 °C,
and mean annual precipitation is 1325 mm y-1, with 35-60% falling as
winter snow (Yang et al. 2021). The vegetation is a mixed-conifer forest
and soils are derived from granitic parent material. Ion exchange resin
capsules were installed in three-dimensional plots over multiple seasons
and years. Data include soil nutrient (phosphate, ammonium, nitrate,
sodium, calcium, and magnesium) concentrations (micromole per squared
centimeter) and fluxes (micromole per squared centimeter per day),
designation of resin locations as soil nutrient hot spots (binary; 0 not
identified as a hot spot, 1 identified as a hot spot), volumetric water
content (average from 10, 30, 60, and 90 centimeter depths; meter cubed
per meter cubed), daily precipitation (millimeters), and penetrometer
measurements of soil resistivity (0, 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20,
22.5, 27.5, 30, 32.5, 35, 37.5, 40, 42.5, and 45 centimeters; kilopascal).