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Freshly fallen P. wrightii litter was collected from these same surrounding trees and air-dried at room temperature in the laboratory before being placed into 15×15 cm litterbags. Litterbags were made from either 75 μm (small) nylon mesh (Miami Aquaculture, Boynton Beach, FL, USA) or 1.5 mm (medium) fiberglass mesh (Adfors Saint-Gobain®). Twenty replicate bags of each mesh size were filled with 3 g dry-weight of leaves (whole or large pieces as necessary to reach the target weight) prior to being stitched closed with a sewing machine then placed into zip-top plastic bags for transport to the compost pile. The pile was partially deconstructed so that bags could be placed into the center of the pile where biological activity is greatest, side-by-side on a relatively flat plane. Strings were attached to a corner of each individual litterbag, which were extended to dangle outside of the wooden frame with their tags showing. The top of the compost pile was then replaced, and the litterbags incubated for a total of 12 weeks. At 20, 41, 63, and 83 days, four replicate litterbags were collected from each mesh size by gently pulling the strings to pull litterbags laterally out of the pile without having to disturb the entire pile again. Mass loss due to handling was determined in a time 0 set of bags that were immediately returned to the lab and measured for initial litter properties.

At each collection date, four litterbags of each mesh size were gently pulled from the compost pile, placed in individual plastic zip-top bags, and returned to the lab at Arizona State University. a stack of five leaves were cored using a 13-mm diameter leaf borer and placed in 10 ml of 4% formalin to preserve the bacteria and fungi present on the leaves. A second core was removed, weighed, and dried at 60˚C for 48 h, and weighed again to measure the weight of the cores (to account for the missing core weight in the calculation of mass remaining) and the water content of the litter at time of removal. The remaining litter sample was placed on a Tullgren funnel for one week, gradually increasing incandescent intensity, to extract arthropods (mostly microarthropods, but also small macroarthropods). Arthropod samples were preserved in ethanol, and later identified. The litter from the Tullgren funnels was then completely dried and weighed, and arthropod abundance was calculated as the number of individuals per g of dry litter.

After extraction of invertebrates, each dried litter sample was removed from litterbags, weighed, then analyzed for carbon, macro- and micronutrients, and fiber compounds. Dried litter was ground to a fine powder using a ball-mill grinder (SPEX Sample Prep Mixer/Mill 8000D). Total elemental %C and %N were determined on an elemental analyzer (Perkin Elmer PE2400, Wattham MA). Percent P, Ca, K, Mg, and Na were measured using a dry ash acid digestion method in which 0.5 g of ground litter (or less if necessary due to low sample availability) was ashed in a muffle oven that was gradually brought to 475°C over 1.5 hours, held at 475°C for 4 hours, then dropped to 105°C until digested in 5 ml of 35% HNO3. Samples were then centrifuged at 25,250×g for 10 min, and the supernatant diluted to 5% HNO3 for measurement using inductively coupled plasma optical emissions spectroscopy (ICP-OES; Thermo iCAP6300, Hudson NH). Litter mass before and after the ashing procedure (prior to acid digestion) was used to calculate ash-free dry mass (AFDM).Sequential acid digestion was used to assess the fraction of fiber compounds present in the litter. Briefly, 0.5 g of ground sample was placed into fiber filter bags and then digested in a fiber analyzer (ANKOM A200 Fiber Analyzer, Macedon, New York, USA) using first a neutral detergent to dissolve soluble (NDS) compounds, followed by low-normality H2SO4 detergent to dissolve acid-detergent soluble compounds (ADS, frequently correlated with hemicellulose), then 72% sulfuric acid to dissolve H2SO4 acid-soluble compounds (AS, frequently correlated with cellulose). The remaining material was identified as acid-indigestible (AI, frequently correlated with lignin). Filter bags were then ashed at 500°C for 5.5 hrs to correct the fiber content for non-organic recalcitrant particles.

Litter bacterial cell counts were enumerated on the litter samples from the first (20 d) and final (83 d) sampling periods. Preserved litter discs were sonicated for 30 minutes in an ice water bath. After sonication, 3 ml of the formalin solution was stained with 500 µl 25× SYBR Green before filtering through a 0.2 µm black polycarbonate filter. Cells were enumerated using epifluorescent microscopy (1000×) and categorized by shape (coccoid or rod) and size class (small and large). Cell biovolumes were calculated using equations for the geometric shape size classes and expressed as total biovolume per surface area of litter. Since previous conversion factors from biovolume to biomass have not been established for this site, data are presented as biovolume.