Saturday, February 6, 2010

"The continual exhalation of mosses gives the temperate rain forest much of its essential character; from bird song to banana slugs, it seems as if the entire forest is stitched together with threads of moss" R.W. Kimmerer

Mosses are an entrenched and enchanting part of all forests, and none more so than in the Pacific Northwest. This is because mosses need moisture in order to photosynthesize (and thus produce energy); dry moss cannot grow or reproduce. While other plants have roots that soak up water and nutrients from the ground, and strategies to conserve water, mosses absorb them directly from the air and from rain and spray water, and thus they grow most abundantly in consistently moist places. Luckily for them, mosses are poikilohydric- they dry out when the environment is dry, but can revive again once conditions are wetter. Most plants, if dried out completely, will wilt and die. By absorbing and retaining water from air vapour, and slowly releasing it to the ground, mosses actually contribute water to the forest, keeping the soil moist for trees and other plants to grow. As mosses increase, so does humidity from their ‘exhalations’, bringing about favourable conditions for even more moss to grow.

Their role in forest ecology is tied to, but goes far beyond, water balance. Mosses are preferred seedbeds for many tree seedlings, they get woven into the nests of many bird species (often providing a cushion for their eggs), are food for slugs, and countless insects and fungi depend on them for habitat. Large wet moss mats may contribute to the infrequent fire cycle in our regional forests- lightning may smolder on moist moss, but will never ignite. Ferns and other plants that grow on trees do not root directly into the tree bark; they depend on moss to be a substrate. Mosses are not eaten by most animals (including humans) due to the tough compounds in their tissues and their low nutritional value. This is used to good advantage by hibernating bears though- prior to getting into their dens bears will eat mosses and other tough fibrous vegetation, in effect producing an “anal plug” that keeps them from defecating through the winter.

Being food-focused to a fault in my foraging, the many ecological and human values claimed by mosses are an inspirational reminder for me to keep a broad outlook. Consider that historically, dry mosses were used as diapers and as menstrual pads- their combination of absorbency and large air spaces would effectively wick moisture away, while providing mild antiseptic properties that no doubt prevented diaper rash. They were used as lamp wicks, scrubbing dishes, insulation for humans (Otzi, the “Iceman” preserved in the European Alps, had his boots packed with Neckera moss to keep his toes warm) and for homes (e.g. chinking cracks in log cabins), a component of artisan works, and used in food preparation. Salmon were scrubbed with moss prior to being dried, while camas pit-cooks used moss as a source of steam during the cooking. Linnaeus, the father of modern plant taxonomy, bedded down on a portable bedroll made of polytrichum moss during his botanical explorations. It is not known whether he used a pillow made of Hypnum moss (think ‘hypnosis’) that was said to impart special dreams to the sleeper.

Human use of moss today is focused on epiphytic mosses (those that grow on trees) as decorative floral products. Every year tens of millions of kilograms of moss are harvested from the Pacific Northwest, bringing in tens of millions of dollars. Much of this takes place in National Forests of Oregon and Washington, but includes British Columbia (for which les information is available). Moss harvest has been significant since the 1940s, originally for use as a fruit-packing material, and has increased in the past couple decades as alternatives to timber harvest have been sought. It has shifted from patchy harvesting by local residents looking to supplement their income, to full time strip harvesting by seasonal crews from outside the region. While regulations exist, they are criticized as being insufficient and poorly enforced. Modeling exercises have projected the depletion of mosses in some areas if current harvesting rates continue, and some National Forests have enacted a moratorium until better management can be demonstrated. Ecologists are working to develop guidelines based on scientific and local knowledge of moss distribution and growth patterns. Peat moss harvesting from our boreal forests for use in gardening is a topic for a whole other ‘Non-timber Tidbit’.

A less commercial human use of moss is to monitor pollutant levels. Mosses usually lack a protective cuticle, and so they readily absorb heavy metals and other substances from the air and rainwater. Since they are often widespread, abundant, and grow in regular patterns, they can be appropriate tools for “bio-monitoring” pollution over time and space.

Recipes for such a non-edible forest product being scarce, the following one for Jamaican Sea Moss Drink, while having no relation to mosses as we know them, may be appropriate, as it includes the tropical non-timber forest products cinnamon, nutmeg, and the beautiful orchid vanilla, as well as the red algae carrageen:

- 1.3 L water
- 15 g dried carrageen
- 400 g condensed milk
- 1 cinnamon stick
- 2 tp linseed /flaxseed (optional)
- Freshly-grated nutmeg
- Few drops of vanilla extract
- Little rum to serve (optional)

Soak the carrageen in cold water for about 15 minutes. Drain and place it in a saucepan with water, cinnamon and linseed and bring this mixture to a boil and cook until it begins to thicken. Strain the mixture using a sieve and discard the seaweed, linseed and cinnamon stick. Pour the liquid back in a pan and add condensed milk, vanilla essence and freshly-grated nutmeg. Boil the mixture and whisk vigorously to cool it. When this mixture begins to set, whisk it again vigorously and when the mixture cools, whisk once again and then finally cool it in the refrigerator. Before serving, whisk it again and add a dash of rum.