The word ‘rich’ can conjure up all kinds of images. Money, opulence, extravagance, the nasty politics of wealth disparity. Cake with a lot of butter in it. If you are a naturalist in Vermont, you won’t know much about being rich, but the word rich may instead call to mind maidenhair fern, wild leeks, dolomite ledges, and soggy meadows filled with sedges and shrubby quinquefoil. In a land where water is rarely hard to come by, and where the hardships of winter spread across the entire state, the limiting factor for ecosystems is often nutrients. The rich, ‘sweet’ soils in many of Vermont, derived from sedimentary rocks high in calcium, are largely to thank for riches like spring ephemeral wildflowers, unique wetlands, and the abundance of sugar maple and thus maple syrup.
All the rain and snowmelt of Vermont mean that plants rarely are short on water, but it comes at a price. The water leaches away nutrients, and over time it makes the soil poor, and also often acidic. Conifer trees accelerate this with their needles. In a conifer-dominated, wet forest like the one I wrote about in my last blog post, the soil can become very acidic indeed – I measured a pH in this forest lower than that of strong black coffee – around 4.2. Other forests, however, have the fortune of occupying soil derived from limestone, dolomite, marble, or other rich rocks. These rocks, which formed on an ancient sea floor out of coral and other life forms, are both high in calcium and also act as a buffer to pH. Soils in a rich forest like the one photographed above near Equinox Mountain have a mostly neutral pH – this one was right around 7, which is exactly neutral. These soils provide abundant nutrients for species that can use them – like sugar maple and basswood.
Rich forests are a joy to visit any time of year. It’s no surprise that a forest full of sugar maple is beautiful in the fall. Even in the dead of winter they are notable for the towering trees – rich forests grow fast, and in a state with almost no old growth forest left, a rich forest is a good place to see big trees. when the thaw comes, many rich forests are used as sugarbushes, and tubes and taps pop up to drain sugar maple sap for the production of delicious maple syrup. A few weeks later, the hidden secret of the rich forest really pops up – spring ephemerals.
As the name implies, spring ephemerals are only visible for a short period of time in spring. These fascinating wildflowers are able to tolerate spring’s hard freezes, and use that ability to leaf out and flower weeks before the trees above leaf out. This allows them to fully take advantage of the strengthening spring sun. Spring ephemeral flower displays can be diverse and beautiful and they are at their best in rich forests.
In the summer, rich forests are incredibly lush. The understory of the forest is filled with herbs – from pretty but uncomfortable wood nettles to the fascinating creepy berries of baneberry to lush carpets of maidenhair fern.
Above: Red baneberry, a fascinating but poisonous rich woods plant. This plant serves as a reminder: just because a berry is red and birds are eating it doesn’t mean you can eat it! It is toxic to humans but apparently not to birds.
Rich woods only occur on rich soils and generally relatively wet areas as well. Sometimes there is a sharp boundary as is the case in the photo below – the barren understory on the right is on a south-facing, warmer, drier slope, and doesn’t support a rich forest.
There is also an unusual sort of open wetland that occurs in areas of rich soils and nutrient-rich groundwater – rich fens. These are wet clearings of sedges and small shrubs – one of the only natural types of clearing in our wooded state.
Rich fens often support rare plants. They are similar to poor fens and bogs in that they occur on an accumulation of peat – deep wet organic matter that does not decompose. Instead of sphagnum they support non-sphagnum mosses, sedges, and shrubby quinquefoil. Often they are at the headwaters of streams, and rushing, mineral-rich water comes out of their downstream end.
I tested the pH of the water coming out of a seep on our property and the pH was neutral. I wonder if our land once held a rich fen or rich seepy woods. It will be interesting to see if I can find any of the indicator species popping up and encourage them to grow here.