Investigating bogs is a part of the study of the same forest history that has kept Mike Kudish busy since his student days over four decades ago. Mike has explored 93 bogs in the Catskills, some of which turned out to be 10,000 to 12,000 years old. Bogs are not only special habitats for living plant and animal species, some of them rare or highly specialized, bogs are also archives of local and regional natural history. Because in bogs organic decay lags behind biomass production from plant growth, plant remains accumulate in annual layers. Like the pages of a history book, these sequential layers can be read by paleobotanists. Past changes in vegetation and species composition are revealed by fossil remains, including leaves, twigs, pollen, and DNA, which we have recently learned to read. Past ecosystems can be virtually reassembled, past climates inferred, and present conditions set and analyzed in a historical context.
Bogs are wetlands, distinguished from marshes and swamps by origin, hydrology vegetation, and chemistry. Most bogs in the Northeast formed in basins created by the glaciers, either scoured out or left empty when big chunks of ice embedded in the ground melted. Water filled these depressions, and many retained water - from precipitation, runoff or groundwater - at a level that ensured the persistence of aquatic and wetland vegetation for thousands of years.
Changes in vegetation and species composition followed the initial lake or pond stage as organic debris built up, from the edge or from the center, depending on initial and changing conditions, in part directed by living plants. The most influential of these is Sphagnum moss, which tolerates the typically acid waters of new lakes, requires minimal nutrients to grow, and is buoyed up by its own dead growth of previous years. Remains of Sphagnum and other bog plants get thicker over time, and denser due to compaction.
This compressed material is called "peat," and has been mined traditionally to provide gardeners with the mulch commonly called "peat moss." Hundreds of years of bog history may be encompassed by a few inches of peat depth.
Other bog plants contributing to peat content are woody shrubs of the heath family such as leatherleaf, sheep laurel and bog rosemary. Wiry, trailing cranberries are also heaths, and inveterate bog dwellers as well. These acidic bog plants may share space with grass-like sedges and rushes, dominant plants in less acidic, mineral-rich fens and marshes. Deep peat or patches of mineral soil in bogs support trees such as red maple, tamarack and spruces, which provide shade, shelter, forage and nesting space for living animals, and add to peat content over time. Thus bog strata may contain evidence of past animal life as well as plant life.
To get at this biological information a bog has to be sampled with an instrument called a "corer." The corer is a pair of sharp, curved blades that carve out a column of peat, pushing it into a long metal tube as it cuts down into the sediment column. Most of the organic material of the core is carbon, so the strata can be carbon-dated fairly accurately to provide a post-glacial sequence of vegetation and climate data, along with animal fossils, occasionally even large mammals such as mastodons.
Our deep hopes for the bog we explored at Yankeetown Pond did not pan out. This was a floating bog of the moat type, having a band of open water (the moat) between the shore and the bog. Probing the bog mat with a metal rod revealed open water beneath the mat, and a mat depth of only a few feet. As we were packing up a local resident told us the bog had been there only about 20 years or so. It was relatively new, in its infancy by bog standards.
Nevertheless we considered the day a success. We had basked in the warm sun, sharing the last 65º day of the fall with autumn red dragonflies, crows, ducks, water-walking spiders and a late-lingering grasshopper. We shared lunch and conversation with Mike and Julia, topped off with wild cranberries from the bog. The bog escaped our intrusion largely unscathed, save for a few small holes that some creatures might find useful. ++