Stop 3 — Lagg Zone

A lagg is a sharp ecotone change in plant composition and soil type (mineral to organic in this case). It interfaces between the basic upland forest and the acidic fen environment, acting as a buffer between the two. As a result, soils here are comprised of both organic and mineral components.

Conditions such as seasonal inundation and water level fluctuation are often too extreme for permanent vegetative growth to exist longer than a season or two.

Note the different vegetation in this area: herbaceous plants such as jewelweed and clearweed grow in the middle of the lagg, while along the edge of the lagg you will find yellow birch, silver maple, cinnamon fern, and royal fern.

Stop 4 — Area With Excavated Peat

Conditions within both bogs and fens create an anaerobic environment with little or no oxygen and therefore accumulation of peat occurs. The difference is that bogs have no inflow or outflow of water whereas fens have some inflow. There is a small stream flowing into Spongy Lake at the southwest corner which makes it a fen.

This site was formerly used for peat extraction on a small scale. Peat is sold in garden centers to help retain moisture in gardens. There’s an average depth of about 5 metres of peat at Spongy Lake, which is a substantial amount considering that it takes about 100 years to create just 20 centimetres of peat.

Slow vegetation decay due to anaerobic conditions means that the history of peatlands can be observed through cores. Pollen, insects, tree roots, and et cetera may be preserved and can be useful for researchers when gathering historical evidence of climate fluctuations and previous community composition.

The slow rate of decay also moderates the climate, creating a cooler microclimate in the summer, and a warmer microclimate in the winter that can reduce freezing and provide shelter to wildlife.

A significant amount of carbon is stored in peatlands like this but disturbing the area can cause it to dry up and become a source of carbon. When peatlands dry out, organic material starts to decompose and release methane that can ignite. Smouldering peat fires can burn for hundreds of years and release large amounts of greenhouse gases. There may also be a rotten egg smell in the area caused by hydrogen sulfide.