It’s that time of year again, when children go back to school, the days are getting shorter, the nights chillier and the colours of our deciduous trees start to change. Many ofΒ Haliburton Forestβs visitors make a special point of timing one of their last visits before Winter to coincide with the height of the change in leaf colour β a spectacular display of vibrancy and natural opulence in shades of everything from bright yellows, fancy purples, vibrant reds and muted browns … and all that before the background of the various tints of green maintained by our conifers!
On a sunny Fall day, the height of the Autumn colours can be truly spectacular and breath-taking. Accordingly, tourists flock into central Ontario, which offers some of the most spectacular colour displays globally.
But why are colours in Haliburton better than in Guelph, Vancouver or regions in Europe, or on the southern hemisphere where deciduous trees are also common and Fall conditions are similar to those enjoyed here? Before we answer that question, let us first look at what causes the colour of a leaf to change from green in the summer, to the pallet of paints we expect to see every Fall.
The primary function of a leaf is to catch the sunβs light. The leaf uses this light as energy to convert water and carbon from the air into sugars and starches, the βfoodβ which enables trees to live and grow. This process, called photosynthesis, occurs in cells referred to as chloroplasts that are filled with a green pigment called chlorophyll. Because of the dominance of chlorophyll in the leaf in Summer, other pigments in the leaf do not appear visually. With shorter days and a less powerful sun in Fall, many of the chlorophylls are being used up and not replaced, making room for other pigments to show up. The most prominent being a group of carotinoids that can be found in the leaf throughout the Summer in small quantities. Carotinoids can be yellow, orange or red depending on their concentration and configuration, which depends on the species of tree and the conditions at the time. Other pigments, especially anthocyanins, only form in the Fall, often from the disintegrating chlorophylls, and are responsible for the dark reds and purples found in species such as red maple (thus the name).
Over the course of Fall, trees will increasingly restrict the access of water and nutrients to every leaf, which disallows the leaf to maintain the pigment levels in its cells, eventually resulting in a dry, bland coloured leaf ready to fall off. By that time few sugars and nutrients remain in the leaf. They have been translocated into the treeβs roots and trunks for storage over the winter. This process is being boosted by frost and the ever declining length of days throughout the Fall.
But let’s come back to our intial question: Why is this process more dramatic and the resulting colours more spectacular in Haliburton versus Guelph, Vancouver, Stockholm or Melbourne? Firstly our Fall weather is more dramatic, with a rather sudden change from Summerβs 30 degree days in August to the first frosts of October within a short six weeks. Also, the fact that frost is encountered at all, contributes to some of the vibrancy of our Autumn colours. However, the main reason is the diversity of our forests. In most other parts of the world, hardwood forests consist of only a handful of species, while we have 27 different species at Haliburton Forest, with 19 of these being hardwoods. Every one of these features a prominent, yet distinct colour, such as red maples their fabulous red, poplar and ash a bright yellow, sugar maples and basswoods tints of orange, and beech or oak shades of brown. Interspersed amid the hardwoods are the green softwoods, 
which display their various shades of green as complimentary colours to the reds, oranges and yellows, increasing their vibrancy and impact. Man could not have designed it any more spectacular, which is why we marvel at our Fall colours every year!
Visitors can experience the Fall colours at Haliburton Forest in many ways. If you only have a few hours of time, take one of the short hikes on some of the trails near basecamp. To see the colourful tree canopy up close, join us for a canopy tour. If you can stay multiple days, book one of the semi-wilderness campsites or one of our housekeeping units. Bring a canoe or kayak and enjoy the spectacular colours from land and water throughout different times of the day. And don’t forget your camera – the colourful leaves offer many photo opportunities, from fantastic landscape pictures to macro photos.
Check out our Fall colour gallery for more fall pictures.
Peter Schleifenbaum
