Forest mushroom fungi form partnerships with tree roots to help them get nutrients from soil. This research proposes that these fungi fall into two main types along a spectrum: ‘absorbers’ that quickly build large fungal networks to capture easily available nitrogen, and ‘miners’ that slowly grow elaborate cord systems to break down difficult organic matter and extract nitrogen. The study uses math models to show how different fungal strategies affect both how much carbon the trees provide and how much nitrogen returns to the trees.