Decline of Gomphus \u3ci\u3eFraternus Fraternus\u3c/i\u3e (Odonata: Gomphidae) in Lake Erie

Collections and literature reports indicate that Gomphus fraternus fraternus was abundant on the shoreline of Lake Erie prior to 1960, and tens of thousands were reported at Long Point Bay. After 1960 there were no reports from the shoreline, although there have been a number of comprehensive studies that have included the shoreline area and a number of Odonata specialists have also visited the Lake Erie shoreline regularly. A survey of portions of the Lake Erie shoreline, including the Long Point Bay area in 1999 and 2000, during the established peak and late peak flight period in southwestern Ontario, did not result in any observations. It is concluded that G. fraternus has declined substantially in Lake Erie and is possibly extirpated from the lake. The decline appears to have occurred between 1950 and 1960, and thus approximates the mid-1950s decline of burrowing mayflies in Lake Erie, which has been associated with warm weather oxygen depletion and pollution. Although it may never be possible to precisely deter- mine the cause of the decline of G. fraternus, it is likely that a number of factors are involved including climatic warming, pollution, changes to the shore- line, other effects of shoreline development, and introduced species

On the Occurrence of \u3ci\u3eOarisma Garita\u3c/i\u3e (Reakirt) (Lepidoptera: Hesperiidae) in Manitoulin District, Ontario

(excerpt) On 26 June, 1976, I stopped to examine plants and collect insects on the alvars or limestone barrens on Great La Cloche Island, north of Little Current in Manitoulin District, Ontario. 1 was especially interested to learn whether or not there were any insects of western affinity in this area since some of the plant species present are at, or near to, the eastern limits of their distribution (Catling et al., 1975). It was mild and sunny, and insects were abundant. Within a few minutes 1 noticed a dark, fast-flying skipper that otherwise resembled Thymeliczrs lineola (Ochsenheimer). The dark colour and whitish veins on the hind wing beneath suggested Oarisma powesheik (Parker), a midwestern species known in Michigan since 1893 (McAlpine, 1972) and recently discovered further to the east and south within the state (Holzman, 1972; Wagner, 1976, pers. comm.). However, the relatively small size made this identification unlikely. 1 captured a few specimens, but had to leave the area without investigating the habitat, abundance and local distribution of the unfamiliar butterfly. The earliest opportunity for further investigation came a week later on 3 July, when I was again favoured with a warm sunny day. After collecting in a variety of habitats, I finally arrived on the alvar on the west side of highway 68 in the immediate vicinity of McGregor Bay, La Cloche Peninsula (ca. 46 02\u27 North, 81°46\u27 West). I collected several specimens of the strange little skipper and saw at least 20 within one half hour, then continued south on highway 68 onto Great La Cloche Island. Here south of the highway and the Canadian Pacific railway tracks, and south and west of Lewis Lake (ca. 46 OO\u27 North, 81°52\u27 West), I found at least 10 more of the skippers in similar alvar habitat. Both of these locations are south of Espanola and north of Little Current in the North Channel, Manitoulin District, Ontario

Dragonflies (Odonata) Emerging from Brackish Pools in Saltmarshes of Gaspé, Quebec

Enallagma hageni, Lestes disjunctus, Sympetrum costiferum, Sympetrum danae, Sympetrum internum, and Sympetrum obtrusum were observed emerging from brackish pools with an overall salinity range of 6.0-17.3 ppt in three saltmarshes in Gaspé, Quebec. Lestes congener, Libellula quadrimaculata, and species of Sympetrum were prominent among the larvae in these pools

A Potential for the Use of Dragonfly (Odonata) Diversity as a Bioindicator of the Efficiency of Sewage Lagoons

In order to determine whether a relationship existed between water quality and odonate fauna in sewage ponds, data were gathered at each of six ponds of similar construction and equal size and depth in an adjacent series of improving water quality at a lagoon system near Embrun in eastern Ontario. Numbers of nymphs of different species of Odonata were recorded in spring and fall, and similar data was collected on adults in June and July. The data on species presence and abundance for each of three pairs of cells in the sequence was then compared with the corresponding chemical data which included biological oxygen demand, total phophorus, total nitrogen and suspended solids. Water quality improved through the system and species diversity in the final ponds was twice that of the ponds receiving wastewater. Numbers of individuals also increased through the system. Occurrence of Anax junius, Enallagma civile and Ischnura verticalis alone was associated with poorer water quality. Higher diversity including Lestes disjunctus, Leucorrhinia spp. and Erythemis simplicicollis, indicates higher water quality. A potential exists for Odonata species diversity, numbers of individuals and occurrence of particular species to be used as a bioindicator of water quality and a means of evaluating efficiency of a lagoon system. Advantages include data that reflects a time period rather than a point in time and also low costs

Additions to the Flora of the Continental Northwest Territories from the Great Slave Lake Area

Eleven species are reported as new to the flora of the continental Northwest Territories. The new native species include Artemesia dracunculus, Chenopodium leptophyllum, Eleocharis erythropoda, Panicum capillare, Schoenoplectus pungens and Symphyotrichum lanceolatum subsp. hesperium var. hesperium. New alien species reported include Achillea ptarmica, Chaenorhinum minus, Galium aparine, Malva neglecta and Silene cserei. Sonchus arvensis, previously reported, is based on material referable to a subsp. uliginosus. Forms new to the flora include Achillea millefolium f. rosea and Actaea rubra f. neglecta. Locations, habitats and distinctive features are provided for the additional taxa. The Hay River lowland ecoregion is a floristically rich area that deserves more botanical exploration. Erratum included

Identification and Status of the Introduced Black Pine, Pinus nigra, and Mugo Pine, Pinus mugo, in Ontario

Recent reference texts and other sources are contradictory regarding the spread of Pinus nigra and Pinus mugo from cultivation in Ontario. Both species have reproduced from plantings along roadsides but neither has been observed to occupy habitats in Ontario to the substantial reduction or exclusion of native species, or to substantially invade natural habitats. The more widely planted Black Pine has been recorded spreading at 24 localities throughout the eastern part of southern Ontario. Mugo Pine is reported spreading at 18 locations. Although evidently much less aggressive than Scots Pine (Pinus sylvestris), both Black and Mugo pines have a potential for negative impact on biodiversity in dry, rocky or sandy habitats, especially in connection with extensive plantings. A key for the identification of two-needle pines is included. Both P. nigra and P. mugo are highly variable and reported to hybridize extensively with other species

Dryopteris goldiana × D. intermedia, a Natural Fern Hybrid New to Canada

The rare fern hybrid Dryopteris goldiana × D. intermedia is reported for the first time from Canada on the basis of a collection from eastern Ontario. The plant occurred in rich deciduous woods in an extensive seepage area at the base of a slope. The immediate vicinity had an unusually high floristic diversity and 25 associated vascular plants are listed. Distinguishing characteristics of the hybrid are outlined

The Extent and Floristic Composition of the Rice Lake Plains Based on Remnants

A study of the floristic composition and extent of the Rice Lake Plains in central southern Ontario was undertaken to provide a basis for protection and management and to contribute to a better understanding of pre-settlement vegetation. During field reconnaissance 42 remnant sites were discovered. Complete species lists were generated for 24 of these sites and a total of 260 native species was recorded of which 61 were present at more than half of the sites. Less than 10% of the native flora of dry, open ground is believed to be extirpated. The most frequent species and those dominating many of the remnants included Andropogon gerardii, Carex siccata, Ceanothus americanus, Pteridium aquilinum, Sorghastrum nutans, and Toxicodendron rydbergii, all of which are characteristic dominants of tallgrass prairie and related habitats in the midwest. It is believed that both composition and frequency are much the same, but not exactly the same, as existed in pre-settlement times. A principal coordinate analysis based on Jaccard’s coefficient derived from a matrix of presence/absence data for 84 regionally rare species in 24 sites revealed three major groupings: (1) open sand and characteristic sand barren flora, including Dichanthelium sabulorum, Carex merritt-fernaldii, Cyperus lupulinus, Polygonum douglasii, Selaginella rupestris, and Sporobolus cryptandrus; (2) prairie sites with Desmodium canadense, Monarda fistulosa, Penstemon hirsutus, Ranunculus rhomboideus, and Schizachyrium scoparium; (3) high-diversity sites with savannah vegetation, including species characteristic of both prairie and open woodland, including Asclepias exaltata, Desmodium glutinosum, Erigeron pulchellus, Solidago arguta, and Taenidia integerrima. Correspondance analysis suggested a succession from sand barren to woodland and ordered species along a successional axis. In addition to three major associations, there was some regional variation with closer sites sharing species such as Lupinus perennis, Liatris cylindracea and Dichanthelium oligosanthes. The probable extent of plains vegetation revealed by remnants was determined by overlaying remnant sites on the soil landscapes and soil types to determine the extent of the associated soil or landscape thus providing a clue to the extent of the plains vegetation. Results of both the soil landscape and soil data analyses were subjected to restrictions based on exposure, elevation and historical information so as to develop a concept of minimum area. The minimum area of plains vegetation including prairie, sand barren and savannah was estimated to be 263 km2 on the basis of distribution of appropriate soils and 590 km2 on the basis of soil landscapes. Thus the Rice Lake Plains included an area of prairie, savannah and sand barrens approximately 600 km2 in extent and extending as an essentially continuous band 123 km long and up to 25 km wide along the top and north slope of the Oak Ridges Moraine from the Ganaraska Highland west of Rice Lake eastward to the Murray Hills and the Trent River and was one of the largest areas of plains vegetation in the eastern Great Lakes region

Some Wild Canadian Orchids Benefit from Woodland Hiking Trails - and the Implications

To clarify the impact that trails have on orchids we compared the occurrence of orchids on the lightly trampled edges of bare trails, with the occurrence of orchids in the surrounding woodland and noted the degree of disturbance. A two-way mixed analysis of variance, using six trails from across Canada, indicated that location by distance strata interaction was lacking. Orchid densities were consistently higher within a few meters of the bare portion of a trail than further away. The width of the disturbance gradient for two well-used trails in parks in Bruce County, Ontario, was determined with regression to be within 1 m from the edge of the bare portion of the trail. Calypso bulbosa var. americana on trails in in Alberta, Epipactis helleborine and Goodyera oblongifolia on trails in Ontario, Goodyera repens on trails in Northwest Territories and all native orchids (cumulatively) on trails on Flowerpot Island, Ontario demonstrated consistent and significant increased abundance within the trail disturbance gradients in comparison to their occurrence in the surrounding forest. More flowering plants of Goodyera oblongifolia and mature capsules of Epipactis helleborine occurred in the trail disturbance gradient than beyond suggesting a beneficial impact on fecundity. The disturbance gradient effect likely includes light trampling which reduces competition, compacts soil, and exposes mineral soil. The effect also includes increased light and microclimate differences near to the path. Landscape managers should recognize that in some situations orchids may benefit greatly from trails and that trails may be better considered as a benefit than as a problem