Mosses are Truly Eco-FriendlyOffering outstanding year-round beauty as well as environmental solutions in modern times. Botanical characteristics and physiology of bryophytes enable these inconspicuous plants to have survived literally for millions of years. Through major climatic changes and hardships, bryophytes have been "greening" our world in an astounding range of habitats and micro-climates, growing on an array of surfaces (substrates). If we interpret these factors, the horticultural potential for the intentional and successful use of bryophytes in today's world is promising.
It becomes apparent that generalizations about mosses must be sorted and bryophyte-specific determinations considered for which mosses to use in which places. This Mountain Moss site provides an overview. If you want to explore more about bryophytes from a more scientific perspective, a visit to Dr. Janice Glime's Bryophyte Ecology eBook is recommended.
Bryophytes function as pioneer plants and are the first colonizers of seemingly unhospitable places. Their purpose of breaking down rock surfaces and enriching soil has continued for millions of years. Even today, mosses prepare locations for the re-growth of other plants by contributing to soil development. Some bryophytes are the first plants to appear after a fire or on substrates that have been exposed to external pollutants (e.g., Funaria hygrometrica and Ceratodon purpureus). Some mosses and liverworts have evolved mechanisms to tolerate extreme conditions and the negative effects of copper mining or other heavy metal residues. In our forests, nursery logs and bryophyte mats still provide ideal sites for the germination of vascular plant seeds, thereby completing the forest life cycle.
Practical Perspectives in Physiology
- Require moisture to thrive and reproduce – brief hydration periods to heavy rainfall
- Major source of sustenance - rainwater-mist-dew and nutrients attached to dust particles
- Tolerant of desiccation or long periods of dryness -- dormant stage
- Leaves curl up as mechanism to survive dry periods with chlorophyll going through change in structure.
- Individual plants comprise colonies as a method for retaining moisture together.
- Sun exposures range from shade to direct sun – bryophyte-specific.
- Tolerant of various types of soil conditions and pH ranges – bryophyte-specific.
- Although no real roots, rhizoids attach to substrates, even vertical surfaces, effectively holding plant colonies in place.
- While mosses are considered to be non-vascular plants, some bryophyte types have developed internal mechanisms to conduct water with stronger, upright stems that grow deeper in the soil (e.g., Polytrichaceae and Dawsoniaceae).
- Extensive temperature ranges for growth including sub-freezing conditions through production of their own "anti-freeze."
- Unappetizing taste because of phenolic and related compounds that deter herbivores
- Serve as homes for invertebrates and micro-organisms -- insects, lizards, salamanders, tardigrades and N2-fixing blue-green bacteria as well as an endangered species, the Spruce-fir moss spider (Michrohexura montivaga) indigenous to North Carolina and Tennessee.
- Birds use moss fragments for nest-building -- estimated 40 types of birds.
Habitats and Substrates
Bryophytes live in a vast range of places that seem contradictory in terms of environmental conditions. It seems reasonable that a bryophyte exists for many gardening challenges and solutions, most of which have been not been fully explored in terms of horticultural benefits.
Bryophytes can be found everywhere... in your backyard, or the nearby forest, or the local lake, or even in the grocery store parking lot. Whether you travel to the sunny beaches of a tropical island or go climb the vertical cliffs of an alpine peak in frigid cold, mosses can be found. Glimpses of green mosses are universal. Because mosses require only small niches of moisture, their habitats include unexpected small micro-climates -- maybe only a crack or crevice or the shade of a nearby vascular plant offers one of these favorable moss locations. Even the most seemingly undesirable locations, such as nutrient-depleted soils or environmentally-damaged sites, could be colonized by bryophytes. The amazing ability of bryophytes to survive extremes in temperatures and as well as contrasts in moisture availability facilitates their growth.
- Arctic regions
- Temperate climates
- Arid, dry locations
- Tropical rain forests
- Bogs and Fens
- Alpine Mountains
And Urban Locations, Too:
- Parking Lots
With my moss radar on all the time, it's hard to go very far without seeing another bryophyte type or more thriving colonies. The range and variety of substrates or surfaces is extensive that support the growth of mosses.
All types of soils:
- heavy metal concentrations
- understory of grass lawns or as ground covers
Acid to Alkaline pH ranges & Many Surfaces:
- decaying logs
- live barks of trees
- tree canopies
- bases of trees
- tree stumps
- cliff faces
- concrete walls
- asphalt pavements
- roof shingles
Maybe even old leather shoes!