State of the Greater Fundy Ecosystem

GREATER FUNDY ECOSYSTEM RESEARCH PROJECT

UNB Faculty of Forestry and Environmental Management

State of the Greater Fundy Ecosystem

Hayward Brook Watershed Study:
Effects of Forestry Practices on Bryophyte Community Structure and Diversity

Katherine Frego
Dept. of Biology, University of New Brunswick
P.O. Box 5050, Saint John, NB E2L 4L5

Bryophytes (mosses and liverworts) are very simple, primitive plants that have no roots. Instead, they absorb water and nutrients over their whole body surface. Unlike the more advanced “seed plants”, bryophytes reproduce by means of tiny, airborne spores which may travel through the stratosphere, but more frequently land within a few metres of the parent. Spores first germinate into a delicate netlike structure called a protonema, which eventually produces the upright shoots we recognize as a typical moss.

Moss covered boulder (Photo: A. Skibicki)

Forest-floor bryophytes have a wide range of potential effects. They can influence; (a) water relations and nutrient availability, (b) soil temperature; and, (c) seedling emergence and establishment. All these aspects may directly or indirectly influence the growth of forest trees.

In considering forest biodiversity, the “lower plants” (e.g. mosses, liverworts and lichens) are generally not considered, yet they may constitute a large component of the forest in terms of both species and biomass. In the Hayward Brook Watershed study area, over 100 species of mosses and liverworts have been documented to date. More than half the species occurred in only a few locations (< 5% of the quadrats) thus indicating that most bryophyte species were locally rare.

Bryophytes are an important part of mixed and coniferous forest ecosystems, with great impact on water and nutrient budgets, hence forest regrowth. Their biodiversity is poorly documented in mature forests, and their recovery after human disturbance is even less known. If bryophyte species distribution is determined by microhabitat, forest management practices which alter the microhabitat would be expected to strongly influence bryophyte diversity. Alternatively, bryophyte distribution may be controlled primarily by dissemination of propagation units. Regeneration would then be encouraged by management practices that retain scattered patches of viable plants.

GOALS

This project is designed (a) to document the diversity of bryophytes in mature mixed forests, (b) to document the changes in diversity after a variety of forestry practices, and (c) to determine which practices minimize reduction in diversity.

METHODS AND EARLY RESULTS

To date, the study has:

(a) documented bryophyte species, their abundance, and their habitat distribution before harvesting, relative to site characteristics. Our preliminary species list shows species that have not previously been reported for this geographical area.

(b) documented survival of bryophyte species and their microsite distribution immediately after various harvesting procedures, relative to site characteristics and distribution class. This provides information on type and intensity of disturbance associated with specific management practices, as well as on availability of propagation units.

(c) begun experiments under conditions of controlled disturbance regimes, following the results of (b, above) to determine the tolerance of species shown to be present in (a, above), and the naturalpropagules remaining in the soil. .

IMPLICATIONS FOR MANAGEMENT

The study will also generate lists of bryophyte species that may be at risk under specific harvesting and site-preparation treatments. This information is not available in the literature. The results will be used to make recommendations on forest management plans that ensure bryophyte species diversity is maintained, including species which are rare and/or at risk.

Further reading:

Parker, G., J. Pomeroy, and A. Chaisson. 1997. The Hayward Brook Watershed Study (a research project of the Fundy Model Forest): Interim Report (1993-1995). Fundy Model Forest. Sussex, N.B.

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