Dr. Susan Moyle Studlar, Consulting Bryologist

May 28, 2024 – June 2, 2024

We will investigate the rich bryophyte communities of the unglaciated Southern Appalachians during field trips around Highlands Biological Station and adjacent Sunset Rock, followed by laboratory identification sessions using microscopes. Aided by an ecological field guide that emphasizes habitat and multiple traits of bryophytes observable in the field or lab, students will collect and learn to recognize bryophytes (mosses, liverworts, and hornworts) of wetlands, mixed hardwood-conifer forests, rock outcrops, soil, peatmoss (Sphagnum) seeps, cascading streams, and an extensive mountain-top rock barren at Sunset Rock. We will see lush spray cliff communities in a field trip to Dry Falls. In the laboratory, students will use dichotomous keys to identify species and make reference collections. Lectures will focus on bryophyte identification and ecology, including bryophytes as ecological indicators and their importance to succession and nutrient and water cycling, as well as to wildlife for habitat and food. The course is designed for students, botanists, naturalists, and resource professionals interested in bryophyte identification (using microscopes) and ecology. Prior exposure to plants in an introductory laboratory course is essential.

Students should learn to recognize about 50 species or genera of bryophytes featured in field trips and labs and be able to use informal and dichotomous keys (using microscopes) to identify specimens. We shall discuss the ecological significance of featured taxa in the field and lab. The overall goal of this course is to empower students to independently explore the miniature world of bryophytes!
In addition to learning how to identify bryophytes, students should become familiar with the following:

  • How bryophytes differ from all other land plants and from lichens
  • Distinguishing features of liverworts (leafy, simple thalloid, and complex thalloid), hornworts, and mosses (acrocarps, pleurocarps, and peatmosses – Sphagnum)
  • How bryophyte growth-forms (such as cushion) are adaptive for particular moisture levels
  • Strangeness of the bryophyte life cycle from the human perspective: two individuals (gametophyte and sporophyte) with different chromosomal levels comprising one organism
  • Differing roles of gametophytes and sporophytes in sexual versus asexual reproduction
  • Roles of asexual propagules (such as gemmae and fragments) versus sexual propagules (spores) in short versus long distance dispersal
  • Spore release in liverworts (capsules splitting open) versus mosses (actively moving peristome teeth vs pepper shaker mechanism of Polytrichum vs popgun of Sphagnum)
  • Leaf movements of various bryophyte species as they take up or lose water
  • Why male and female bryophytes may be separated for millennia
  • Water uptake by liverworts as related to succubous versus incubous leaf-attachment
  • How bryophytes are dispersed by wind, water, animals, and humans
  • Competition between bryophytes and lichens in nature and how environment affects outcome
  • Symbiotic associations of bryophytes with fungi and their hypothesized survival value
  • Value of bryophytes for wildlife such as homes for small invertebrates and salamanders, nesting material for birds; and food for species that can overcome their indigestibility
  • Human uses of bryophytes past and present
  • Remarkable “resurrection lifestyle” (poikilohydry) of bryophytes as an alternative to that (homiohydry) of other land plants, and why critical to their extraordinary global success
  • Animals such as tardigrades and rotifers that thrive within bryophytes due to similar “resurrection lifestyles” (cryptobiosis or anhydrobiosis)
  • Recent ideas on bryophyte evolution, challenging earlier ideas on their primitive nature
  • Limiting factors for bryophyte distribution: dispersal, disturbance, abiotic factors (light, temperature, water, and nutrient levels), biotic factors (species interactions, including impact of leaf litter), and historic factors (plate tectonics and Pleisticene events)
  • Apparent paradox of many bryophyte distributions: narrow niches and broad distributions
  • Why Polytrichum, unlike most bryophytes, is often competitive with other land plants, including seed plants
  • Why bryophyte distributions tend to be broader than those of angiosperms, although discoveries of molecular species (cryptospecies) are altering our species concepts
  • Why rare bryophytes are often found on cliffs and caves around waterfalls
  • Sphagnum as a keystone genus; how it modifies the environment and stores carbon; and how climate change may lead to massive Sphagnum decline with broad global consequences
  • Why bryophytes are excellent indicators of climate and pollution (water, air, and soil)
  • Roles of bryophytes in cycling of water and nutrients, weathering of rocks, and reducing erosion
  • Bryophyte as pioneers, nurse log species and climax species in succession
  • Distinctive but overlapping bryophyte communities in contrasting habitats, such calcareous (basic) vs. siliceous (acidic) rocks, humic vs mineral soils, hardwoods vs conifers, and quiet versus flowing water; species adaptations to opportunities and stresses of varied habitats
  • Why the Southern Appalachians are especially rich in bryophyte species