The May Count of plant species in flower was conducted in Wagner Natural Area this year on the 27, 28 and 29 May. The areas covered were the Marl Pond Trail including the Succession Field and path leading up to the picnic shelter (a.m.) and the East-West road allowance, Twin Creeks (Morgan Creek), Villeneuve extension south to the Hourglass Marl Pond (p.m., 27 May); Cabin Trail and Villeneuve Field (evening of 28) and parking lot pond, Roadside Pond to Jones’ Pond and Buckbean drainage (p.m., 29).
A total of 63 species were recorded in flower, from species with just one or two plants showing an open flower (stage 4) to populations in which the majority of flowers were already fading (stage 8). Allowing for variations from year to year in observations and interpretation, this is roughly comparable to last year’s total of 54 species. Spring came rather late in 2018 but a series of hot days in May probably enabled many species to achieve their normal or average flowering time.
The plant count assigns presence or absence of flowering, which means stamens are shedding pollen, and the pistils have receptive stigmas. At the discretion of the observer this can be somewhat refined by assigning a flowering stage to the population as a whole (stage 3 to 9, with 4 to 8 being positive for the species concerned). However, assigning a flowering stage is usually a very subjective estimate.
The count is limited to a one-time snapshot of species in flower. Nor does it allow an estimate of the abundance or general reproductive health of a species’ population. For example, the percentage of the common dandelion that is in flower could be estimated at 100% (full flower) but the number of individuals at a given site could be much different from other years’.

Violets and gooseberries

Long-spurred violet (Viola selkirkii) was not checked this year. It occurs only in the eastern spruce woods in Wagner and access is difficult and time-consuming. Based on checks I made of populations in Edmonton’s river valley (no plants appearing at all, probably due to drought) and in the Fath property (almost 100% leaves, only one or two flowers past flowering), I assumed that none would be found in Wagner. (Peak flowering time is mid-May.) Observations in various sites suggest that kidney-leaved violet (V. renifolia; white flowers) is sensitive to drought; in dry woods in Wagner and elsewhere flowering was almost non-existent, but flowers were found in plants growing in the wet swale of Villeneuve extension south. Bog violet (V. nephrophylla), whose peak flowering is the first two weeks of June, always does well in Wagner’s wet fens. 

Along with violets, gooseberries and currants (Ribes species), which also flower during May, are good indicators of early versus late springs.
Mindful of the Father’s Day orchid walk scheduled for the middle of June, we always take an anxious look at the developmental status of Wagner’s orchids. Early coralroot was 25-50% in flower in the aspen woods along the Marl Pond Trail, and just a few blooms were showing on the yellow lady’s-slippers in similar places. Buds were barely visible on the round-leaved orchids along the Trail. In contrast, heart-leaved twayblades were approximately 50% in flower along the Villeneuve Extension South.

Changes in vegetation: species and communities

Observers covering the same area year after year for the Count often comment on any striking changes in vegetation patterns or species they note. A picture often emerges of certain species having “good” (i.e. abundant, with many flowers) and “bad” years.
Changes in vegetation in Wagner are more precisely measured by means of permanent sample plots, assessed approximately every five years.

This year as an incidental observation, however, I noted the continual decline of willows in Wagner. Willows have been lost along the edge of the wetland immediately inside the gate to the west. Flooding, or the ravages of willow and poplar borer may both be responsible here. MacCalla’s willow (Salix maccalliana) has almost entirely disappeared over the years in a drainage hollow just north of the picnic shelter. This is unfortunate as it is not a common willow in Wagner, at least not in accessible places. Likewise, the colony of sandbar willow at the north edge of the Central Field (east of the trail opening) has been reduced to a couple of stems. (Admittedly, this was never a typical or suitable habitat.) The mature willows along the western part of the wooded Marl Pond Trail have been decadent for many years, clinging to life by virtue of producing a few upright shoots. Young willows have not been noted in the vicinity of their parents. I speculate that because of this lack of recruitment the willows here will be replaced eventually by other shrubs and by trees, the species composition no doubt depending on ground conditions at the time of seeding. Recruitment may be hampered by browsing, as some willow saplings planted in the vicinity and elsewhere along the Trail were quickly bitten down to ground level by herbivores.
Mature tall tamaracks growing around the northern edge of the Roadside Pond have been decimated by porcupine, which girdle the trunks.
Heavy browsing by deer and perhaps by moose along the northern part of the Marl Pond Trail has resulted in flourishing fresh green shoots and leaves on the cropped twigs of red-osier dogwood and bracted honeysuckle, but relatively few flowers. Trails of course provide access for animals as well as humans, and have a number of consequences: increased herbivory, increased predation, increased blow-down of trees (which has pros and cons for a woodland ecosystem), increased ingress of weeds and pioneering species (e.g., dandelions, nettles, raspberries), and (human) trampling and creation of extra, informal trails. Trails are, however, essential for humans to appreciate the beauty and diversity of Wagner Natural Area!

Patsy Cotterill