On November 6th I had a delightful visit on Naked Mountain from three important field scientists: Tom Wieboldt, Curator of the Herbarium at Virginia Polytechnic Institute, John Townsend, Botanist with the Natural Heritage Division of the Virginia Department of Conservation and Recreation, and Gary Fleming, Senior Vegetation Ecologist also with Natural Heritage. They arrived early in the day when a cool foggy mist enclosed the summit of the mountain.
These highly experienced field scientists came to the Naked Mountain Natural Area Preserve to collect something no one else had yet investigated: the whole category of tiny plants known as Bryophytes. Bryophytes comprise all variety of mosses, liverworts and hornworts. These have recently been determined to have separate evolutionary histories, but they are still grouped under the name Bryophytes as they share common characteristics, namely that they do not produce lignin to enable the growth of vascular tissue for water and nutrient transport and their reproductive cycle is dominantly gametophyte and haploid (cells contain only one-half of their chromosomes). You can read more about this here.
Lacking vascular tissue means that Bryophytes must absorb water and nutrients through their tiny leaves from the air around them. To retain vital moisture that is essential for their survival and for reproductive growth, the leaves are coated in a waxy cuticle.
Bryophytes are also characterized by the pattern of their growth — in closely packed mats or cushions on rocks, soil, or as epiphytes on the trunks of trees and leaves of forest trees. Gary Fleming noted that mosses act as an agent of primary succession on bare rock and so provide a medium for plants seen on Naked Mountain like the massive numbers of Shooting Stars (Primula meadia) seen in the lower elevation outcrop barrens and especially Fameflower (Phemeranthus teretifolius) that blooms directly in the moss on the flatter barrens. In the case of Naked Mountain which is underlain with amphibolite, the mosses will be specifically adapted to mafic rock. Here is what Gary says about the moss seen in the photo below: “Grimmia laevigata (“Dry Rock Moss”) – characteristic moss of exposed igneous and metamorphic rocks with periodic seepage; abundant in the Naked Mountain amphibolite woodlands and barrens”
Fossil records indicate that Bryophytes are the oldest land plants on Earth. They are believed to be a vital link in the migration of plants from aquatic environments onto land. Ecologically, they are important in maintaining an ecosystem’s humidity level and so can be used as indicators of habitat condition.
Identifying Bryophytes takes painstaking work with a microscope to see the minute branching effects and other features, some only a cell-wide.
After collecting some specimens near the summit at about 1900 feet I took them down into the low elevation outcrop barrens at about 1600 feet where rare plants grow. Here are two of many Bryophytes they collected in that site.
Here are some really cool facts I learned from Tom and Johnny about Bryophytes:
- There are upwards of 25,000 species of Bryophytes with 15,000 species of mosses alone making this plant category among the most diverse on Earth — maybe not surprising given how old it is.
- They occur the world over from the coast of Antarctica to the deserts of Australia and the rain forests of the Amazon.
- Because of this characteristic, there is an international on-line community of Bryophyte lovers, both expert botanists and ecologists and highly informed amateurs, that share information and discuss taxonomy.
- Very little is known about Virginia’s Bryophytes. There are a few experts in the state, but they have only investigated locally. Natural Heritage and herbarium botanists like Tom Wieboldt want to see a digital mapping of Bryophytes for the Commonwealth and so that effort is now beginning. It is surmised that rare species of Bryophytes exist in Virginia.
By the time Tom, Johnny and Gary returned to their car near the summit several hours later, the mist had cleared and they could see the Blue Ridge Mountains from my deck – a late fall view with some hills in the foreground still glowing gold. I was glad they had a chance to see this. Some people who visit Naked Mountain never get to see beyond the white mist.
I was very pleased and proud to be a collection site for this Bryophyte mapping venture and can’t wait to hear what species they found growing in the Naked Mountain barrens!