PEI’s colourful fall leaves are mostly gone, but one native tree is still putting on a show: Eastern Larch, also known as Juniper, Tamarack, or Hackmatack (Larix laricina). Naturalist Aldo Leopold described Larch as “a blanket of smoky gold", and they are among my favourite sights in the otherwise drab Island landscape this time of year.
In October, I described how and why broad-leaved trees pack up their chlorophyll and drop those big snow- and wind-catching liabilities for winter (https://www.pei-untamed.com/post/autumn-leaf-colour). Conifers use an entirely different strategy, growing small leaves that last multiple years. Larch is unique in that it’s a deciduous conifer: a needle-leaved tree that loses all its leaves each year. What’s up with that?
Keeping needles all winter does have a price: it allows snow to build up on the tree, placing tremendous weight on its branches. This can cause branches to break, or entire trees to topple over in windstorms. With no winter foliage, Larch sheds show and avoids this problem.
Not having to worry about snow build up enables Larch to have a more sprawling growth form than its conifer cousins. (Think of the compact, pyramid shape of a Spruce versus the irregular, wiry shape of a Larch). This maximizes the amount of sunlight reaching the needles, enabling them to use the sun’s energy more effectively. Larch needles are powerhouses of energy production, paying for themselves in one growing season rather than over several years.
Its deciduous habit also makes Larch resistant to defoliation from fire or insects. If Spruce, Pine or Fir lose large numbers of needles at one time, they aren’t able to replace them and the tree may die. If Larch is damaged by fire or insects, it may be able to regrow its needles the following spring and survive.
There’s no free lunch, and the advantages of Larch’s lifestyle come with some disadvantages. Key among these is that Larch needles must be extraordinarily efficient and give back to the tree in one season more energy than they took to make. To enhance efficiency, they forego the waxy coating that helps protect other conifers from insects and water loss. Larch’s soft needles are thus more vulnerable to pests and drought.
Larch is common across the Island, though more so in Prince County. (If you need help recognizing it from quite a long way away, Monty Python can help). While there are about 20 species of deciduous conifers around the world, Eastern Larch is the only one that’s a native part of PEI untamed!