(Autumn descends on the Stittsville Wetlands. Photos: Jessie Lozanski)
As winter darkness descends on the landscape and our forests hush it might seem that enjoyment of our natural world has come to an end until spring. Luckily if you are equipped with a curious eye you will find that the wonders of nature persist throughout the entire year. Use this cool autumn period to enjoy some of the World’s most ancient species.
Moss:
Mosses, also known as Bryophytes, are the oldest land plants on Earth. Developing early on the plant evolutionary chain, mosses preceded vascular tissues which are used by most plants we know today to transport water, nutrients and oxygen. Instead mosses absorb water through their leaves instead of roots and reproduce via spores rather than seeds. Looking closely at a patch of moss you might notice tall stalks rising up above the leafy undergrowth- these are called Sporophytes and house the spores that will later spread and grow new leafy shoots called Gametophytes.
Mosses are an often overlooked aspect of the natural world by citizens and scientists alike, many mosses lacking names and almost all mosses lacking common names. Despite seeming to be quiet, non-effectual organisms mosses have a powerful history and are regarded as the cause of the Ordovician Ice Age. Over 440 million years ago, mosses, or rather their ancestors, first spread onto land and began weathering the rocks on which they grew. This weathering changed the chemical composition of the rocks which significantly increased their absorption of carbon from the atmosphere. The loss of carbon dropped the Earth’s temperature by around 5 degrees, plunging the world into an ice age, all caused by a little plant you are unlikely to notice on your morning walk.
Not only have mosses influenced the climate but they are ecosystem builders by maintaining favourable moisture, temperature, and soil for the growth of other plants. Mosses are able to survive in extreme environments from desert heat to freezing Canadian winters so they frequently act as the nursery for less hardy plants.
The next time you are out in the woods take a look at the soft green carpets of moss that climb up tree trunks and curl over rocks. Using a hand lens and a field guide you might be able to identify some of these mysterious plants and wonder at the diversity of their miniature forests.
Fertile Fronds:
Ferns, another spore producing plant like mosses, sometimes grow woody stalks with bead-like pouches full of spores. In Stittsville, these stalks tend to belong to Sensitive Fern, sometimes called Bead Fern. Sensitive Ferns earned their name by being extremely sensitive to frost and will be some of the first ferns to shrivel up as cold weather encroaches. As the fern fronds die off, it will be easy to spot their stalks that persist through the winter. In spring, the beads will dry and burst, releasing thousands of fern spores, of which only a few will actually grow into a new plant. To spot some Sensitive Fern spore stalks look in moist places like the banks of Poole Creek.
Fossil evidence has shown that Sensitive Ferns have changed very little in their appearance since over 60 million years ago suggesting that the ferns we see now looked the same to Earth’s earliest mammals. To look at the stalks of Sensitive Fern is to draw a visual connection between us and every human that has walked on this planet.
Clubmoss:
Yet another ancient spore producing species, clubmoss, is a plant you might confuse for moss or for baby conifer trees growing along the forest floor. Clubmosses are actually their own faction of plants that evolved around 410 million years ago, and are the Earth’s earliest vascular plants meaning they have tissues capable of transporting water and nutrients unlike moss. In their ancient history, Clubmosses were actually one of the most dominant plants on earth and grew to massive sizes, sometimes up to 135 feet tall a few hundred million years ago. The wood of ancient petrified Clubmoss is usually what coal is composed of today. Now Clubmosses are much smaller, usually only a few inches in length but they still persist unlike many species that have developed and gone extinct during their history.
Clubmosses are evergreens owing to ani-freeze chemicals that prevent their cells from bursting in freezing temperature so you are likely to see them all winter long. They tend to grow in moist woodlands so take a look along the forest floor in the Kemp Woodland or the forests around the Goulbourn Wetland Complex to see if you can spot some of these ancient plants.
