The colloquial term muskeg is Algonquian in origin and refers to open peatlands or bogs interspersed with ponds and streams and dotted with stunted trees. Muskegs are widespread in subarctic regions of Alaska and Canada, often breaking up stretches of forest. Their hummocky terrain occupies poorly drained land layered with ancient organic peat at least a foot deep. Water-saturated sphagnum mosses play a critical role in muskegs. These mosses not only keep the water table high, but also release caustic acidic compounds that inhibit organic decomposition, leaving nutrient-poor groundwater. Since other muskeg plants can’t make use of this acidic water, they trap what rainwater they can and have other features, such as waxy or fuzzy leaves, that help minimize water loss. Forest trees bordering muskegs struggle with the waterlogged soils and often die, allowing the bog to expand. This has sparked a debate about whether muskegs ﬁgure signiﬁcantly in forest decline.