Bacteria: 0
Fungi nodes: 0
Organic matter: 0
CO₂ flux: low
N availability: low
A teaspoon of healthy soil contains 1 billion bacteria, 200m of fungal hyphae, and thousands of protozoa. The decomposer network drives all nutrient cycling: bacteria and fungi break organic matter into mineral N, P, K; earthworms shred litter and aerate soil; nematodes graze bacteria, releasing N in plant-available form. Mycorrhizal networks ("wood-wide web") connect plant roots, trading photosynthate for P and water. Temperature and moisture are the master switches — decomposition peaks at 25-35°C and ~60% field capacity.