Peat Bogs (Photo 1) are one of the oldest habitats on the Island; we can trace their beginnings back to the end of the last Ice Age more than 10,000 years ago.
The massive glaciers that scraped across our landscape erased all previous vegetation and most landforms. When they retreated, those ice sheets left some areas piled high with glacial till (sediment left by the glaciers) and others with nothing but low-lying bedrock and no drainage. In these latter sites, water accumulated and algae began to grow, beginning the slow process of Peat Bog formation.
The algae that colonized these damp depressions formed a sort of ooze that provided enough organic matter for plants such as sedges, grasses and - most notably - Sphagnum mosses to establish. Sphagnum mosses are very good at holding water; they trap rainfall and snowmelt, preventing it from evaporating. As water accumulated, mosses continued to grow outward and upward while the older, lower levels died and began to slowly decompose. With so little oxygen in this water-saturated environment, decomposition happens very slowly. Decayed Sphagnum moss - called peat - forms at a rate of about one millimetre per year.
Over thousands of years, Sphagnum continued to grow and peat continued to accumulate. Some PEI bogs have peat deposits more than 6.5 metres (21 feet) deep! Eventually, other plants started to grow in this water-logged, acidic, and nutrient-poor environment, including low-pH-loving Small Cranberries (Vaccinium oxycoccus, Photo 2) and Labrador Tea (Rhodendron groenlandicum, Photo 3). Black Spruce (Picea mariana) and Eastern Larch (Larix laricina) are the main trees of Island bogs, but the tough environment means they grow slowly. A stunted Spruce or Larch could easily be many decades old.
Peat Bogs are so nutrient poor that some of their plants have compensated by becoming carnivorous. Pitcher Plant (Sarracenia purpurea, Photo 4) and Round-leaved Sundew (Drosera rotundifolia, Photo 5), are two examples that trap and digest insects and other small animals to get needed nutrients, especially nitrogen.
Peat Bogs are used by many Island birds, mammals, amphibians, reptiles and invertebrates. They are home to dozens of uncommon plant species (I’ll show you some beautiful bog orchids next week). They filter water, mitigate flooding, and store far more carbon than forests do. They take thousands of years to form and are one of the Island’s oldest habitats. Peat Bogs are unquestionably a cool PEI landscape!