Robert P. Cameron

CYANOLICHENS: THEIR RESPONSE TO POLLUTION AND POSSIBLE MANAGEMENT STRATEGIES FOR THEIR CONSERVATION IN NORTHEASTERN NORTH AMERICA

Abstract This short review focuses on lichens which have cyanobacteria as their main photosynthetic partner or in localized areas termed cephalodia. Research is cited to show that cyanolichens are very sensitive to gaseous air pollution, to acid rain, and to habitat disturbance. These lichens are worth conserving for their own sake but are also valuable for assessing the status of forests in areas like northeastern North America, where forests cover large tracts of land. The richness of the cyanolichen flora reflects biological diversity in the forests. Cyanolichens fix atmospheric nitrogen, are generally nutrient-rich, and have a diverse associated invertebrate fauna. These invertebrates provide food that sustain both resident and migrating birds. Management strategies that might be used to maintain and ensure the survival of the rich cyanolichen flora of the northeastern U.S. and Atlantic Provinces of Canada are presented and discussed.

HABITAT ASSOCIATIONS OF EPIPHYTIC LICHENS IN MANAGED AND UNMANAGED FOREST STANDS IN NOVA SCOTIA

Abstract Differences in lichen presence and abundance in natural and managed coniferous forests of Nova Scotia were studied in thirty stands categorized as 1) harvested and thinned, 2) harvested and unthinned, and 3) naturally disturbed. The frequency of cover of thirty-four lichen taxa was assessed and analysed to examine the effects of forest management history. Nine taxa had significantly greater abundance and two taxa only occurred in old growth forests compared to younger stages. Twenty taxa had significantly greater abundance and five taxa only occurred in natural forests compared to managed forests. The abundance and habitat of each taxon is discussed. Multiple linear regression was used to determine the forest structural features that best explained the abundance of each lichen taxon. Tree age, remnant trees, crown closure, tree volume, and tree spacing were structural features that most consistently influenced lichen abundance.

Heuristic model for identifying the habitats of Erioderma pedicellatum and other rare cyanolichens in Nova Scotia, Canada

Abstract Erioderma pedicellatum and fifteen other rare cyanolichens in Atlantic coastal forests in Nova Scotia are at risk from human activities. A heuristic expert habitat model was developed for use in a GIS to help identify polygons with habitat for these at-risk cyanolichens. Of 13,852 polygons identified by the model, 183 were surveyed for rare cyanolichens. One hundred and one of surveyed polygons had at least one species of rare cyanolichen. Habitat data were collected from twenty sites which had Erioderma pedicellatum. The habitat model can be used to identify important lichen areas for conservation and research.

Macrolichen Indicators of Air Quality for Nova Scotia

Abstract Presence and frequency of epiphytic macrolichens were measured along an air-quality gradient in Halifax City, NS, Canada. Species frequency plots over distance and multidimensional scaling (MDS) suggested lichen-community changes consistent with expected air-quality changes. A provisional list of air-quality indicators was selected based on: 1) demonstrated variation along the air-quality gradient, 2) frequency across the province, 3) literature values of air-quality sensitivity, and 4) ease of field identification. Indicators were placed in one of three classes: 1) pollution tolerant, 2) intermediate pollution tolerance, and 3) pollution sensitive. MDS analysis suggests an elevation gradient in Nova Scotia and this should be investigated with a further study.

Distribution prediction model for Erioderma mollissimum in Atlantic Canada

Abstract Erioderma mollissimum is a rare cyanolichen found on the foggy Atlantic coast of Canada. The rarity of E. mollissimum and the potential threat from human impact has led to conservation concern for this species in Canada. Recent finds on the island of Newfoundland suggest that the distribution of E. mollissimum may be wider than historically known. In order to better understand the environmental factors affecting distribution and to direct future search efforts a Mahalanobis predictive distribution model using a geographical information system (GIS) was developed for Atlantic Canada. The model suggests that only a small part of this region is suitable for E. mollissimum. This study provides an example of an alternative modeling technique to the traditional statistical methods for predicting lichen distribution.

Perhumid Boreal and Hemiboreal Forests of Eastern Canada

Eastern Canada takes in the rugged easternmost prominence of North America adjoining the North Atlantic Ocean. From south to north, and along gradients of elevation and distance from the ocean, it encompasses a range of temperate to boreal forests. Distinctive variants of these forests occur in the wettest coastal and montane areas of the region. They occur discontinuously from the Atlantic Coast of Nova Scotia to southern Labrador (43–52°N latitude), and from the Avalon Peninsula on the island of Newfoundland to the Appalachian and Laurentian highlands of eastern Quebec (53–73°W longitude).

Obituary: Wolfgang Siegfried Gunther Maass 1929–2016

With the passing of Wolfgang Maass, Nova Scotia, Canada, and indeed the entire world of lichenology has lost an important pioneer in the documentation of the lichen flora of northeastern North America and a researcher dedicated to understanding the complex nature of lichen chemistry.

Coral Lichen (Sphaerophorus globosus (Huds.) Vain) as an Indicator of Coniferous Old-Growth Forest in Nova Scotia

Abstract Old-growth forests are rare and of conservation concern in Maritime Canada. A variety of methods have been proposed to identify old-growth forests including structural measurements and lichen surveys. Frequency and abundance of Sphaerophorus globosus (Coral Lichen), was measured in 6 old-growth and 6 mature second-growth coniferous forests in Nova Scotia. Total abundance (P = 0.013) and the tree frequency occurrence (P = 0.005) were significantly greater in old-growth forests compared with mature second growth in paired t-tests. We propose the abundance and frequency of occurrence of the easily identifiable lichen Sphaerophorus globosus as an indicator of old-growth forests. Forests with at least 25% of trees having Sphaerophorus globosus growing on them, or meeting the criteria of at least 50 trees/ha with dbh >40 cm and more than 25% of trees with Sphaerophorus globosus, should be studied further as potential candidates for being assigned old-growth forest status.

Completing an Ecosystem Classification System for Nova Scotia

ABSTRACT: Ecosystem classification systems (ECS) are a useful tool for conservation planning, particularly protected areas planning. Nova Scotia Protected Areas Branch has completed a geographical information system based ecosystem classification system for the province. The classification system integrates aspects of existing forestry based classification system and national vegetation classification system. Principles of landscape pattern have been incorporated into the system: (1) use hierarchical system; (2) include both abiotic and biotic factors; (3) use more abiotic factors at coarser spatial scales and more biotic factors at finer spatial scales; and (4) use vegetation only at the finest scale. The ECS builds on previous work, allows for integration of existing landscape classification systems, and establishes methods that can be applied for a variety of landscape planning issues in other regions.

On the distribution and habitat of Fuscopannaria leucosticta in New Brunswick, Canada

ABSTRACT Fuscopannaria leucosticta is a rare lichen that exhibits an apparent specificity for old wet forests in eastern Canada, and may, consequently, be sensitive to anthropogenic disturbance. Estimates of the current distribution and population size are highly uncertain. Effective conservation planning requires improving our understanding of both its current distribution and the factors that influence habitat suitability. We built a MaxEnt distribution model with interpolated climate data, depth to water table mapping, forest inventory data, and herbarium collection data for F. leucosticta in New Brunswick, Canada. We tested model performance via field verifications in high-probability areas with no record of previous surveys. We found F. leucosticta in 13 out of 22 previously unsurveyed locations with a predicted high probability of occurrence. Selected variables included the presence of cedar in the canopy and a lack of recent anthropogenic disturbance, as well as mean annual rainfall and degree days above 0°C. These associations are likely a result of the lichens low reproductive output and the thermal and hydration requirements of its cyanobacterial photobiont. Our study affirms several previous claims about habitat associations of the species, and provides focus for conservation efforts in the future.