|BOTANICAL ELECTRONIC NEWS|
|No. 517 April 28, email@example.com||Victoria, B.C.|
Three species of moss, Schistidium splendens, S. squarrosum, and S. relictum, have recently been reported for western North America (McIntosh et al. 2015, 2017). These species were previously named by Hans Blom during his landmark treatment of the Schistidium apocarpum complex in Norway and Sweden (Blom 1996). However, they, along with many others in North America, were never described in an accepted journal, so remained as 'manuscript names' (over 20 of these 'species' are yet to be described in North America, as well as some that are present locally in British Columbia; e.g., 'Schistidium vancouverense').
Historically, Schistidium Bruch & Schimper has been a difficult genus to resolve taxonomically (Blom 1996, McIntosh 2007, McIntosh et al. 2015). Past floristic treatments have varied from region to region, and names that have been applied to specimens at both the species and varietal levels have been as inconsistent as the characters used to differentiate taxa (McIntosh 2007). However, numerous Schistidium species have been recently formally recognized (e.g., Blom 1996, 1998, Blom and Darigo 2009, Blom et al. 2016, McIntosh et al. 2015). The majority of these would have once been considered within the broad and uncomfortable species concept of S. apocarpum, although a few were lodged within other broadly defined species, such as S. rivulare (Bridel) Podpera and S. confertum (Funck) Bruch & Schimper. Genetic research has also contributed to the understanding of species concepts as well as species relationships within Schistidium (e.g., Goryunov et al. 2007, Ignatova et al. 2009, Hofbauer et al. 2016). As a result, although more species will be described in the coming years, Schistidium is currently comprised of about 130 species.
Schistidium relictum T.T. McIntosh, H.H. Blom, & E.A. Ignatova Important distinguishing characters of Schistidium relictum include dull, nearly black plants, with stems densely and evenly foliated, appearing columnar, weakly spreading leaves that usually lack awns, and the mostly 1-stratose distal leaf laminae with 2(-3)-stratose margins. It is the most distinctive species of the genus. It has a disjunct distribution pattern between northwest North American and Siberia with most of its known sites having been unglaciated during the Pleistocene glaciations. It is restricted to areas with occurrence of calcareous bedrock, especially limestones. Its distribution in North American resembles that of Andreaeobryum macrosporum Steere & B.M. Murray, which also occurs along the ice free corridor between the Laurentide and Cordilleran ice sheets in the Yukon-Northwest Territoiry-northern British Columbia area. Further, Schistidium relictum was recently discovered in Yakutia, east Russia, and, interestingly, was collected at this site along the same creek as Andreaeobryum macrosporum from 500 to 1100 m elevation. It appears to be rather isolated genetically based on molecular studies of total ITS. Schistidium relictum is a distinctive species only likely to be confused with other blackish Schistidium species, in particular S. andreaeopsis and S. boreale. Schistidium andreaeopsis is a much larger plant with longer leaves (2.0-2.7 mm vs., on average, 1.4-1.8 mm) and wider distal leaf cells (10-12 µm vs. 8-9 µm). Also, its leaf cells are strongly sinuose to nodulose almost throughout and possess characteristic reddish walls, whereas they are esinuose or slightly sinuose in the distal portions of the leaf and lack a reddish wall coloration in S. relictum. Sporophytes are unknown in S. andreaeopsis. The gametophyte of S. boreale is similar to S. relictum, but its leaf laminal cells are distinctly more densely and highly papillose and cells walls often reddish or orange. Also, the peristome teeth of S. boreale are shorter than those of S. relictum (220-330 µm vs. 250-450 µm).
Schistidium splendens T.T. McIntosh, H.H. Blom, D.R. Toren & J.R. Shevock Schistidium splendens is characterized mainly by 2-stratose striae in the distal leaf laminae, thick and strongly recurved leaf margins, relatively short awns, and more or less isodiametric or short-elongate, irregularly shaped exothecial cells. Schistidium splendens is endemic to western North America, reported from California, Oregon, Washington, and British Columbia. It is viewed primarily as a semi-rheophytic species, especially in the southern portion of its range where it is often seasonally submerged or inundated during snowmelt and peak rain events along streams, often in habitats with diffuse light. However, during most of the year the plants are dry. It appears closely related to S. pulchrum H.H.Blom. Both species have margins that are recurved to near the apex, strongly sinuose distal and medial leaf laminal cells, and similar exothecial cell areolation. However, the leaf margins of S. splendens are much thicker and more evident than with S. pulchrum which have 1- or 2-stratose margins. The awns of S. splendens are usually non-decurrent and have relatively short spinulae, whereas awns of S. pulchrum are often decurrent and have longer, sharper spinulae. The laminal cells of S. pulchrum, especially at mid-leaf, are often guttulate or sometimes stellate in appearance. The capsules of S. splendens are longer, 1.3-1.5 mm versus 0.8-1.3 mm in S. pulchrum. In addition, the known range of S. splendens does not overlap with S. pulchrum except in British Columbia.
Schistidium squarrosum T.T. McIntosh, H.H. Blom, D.R. Toren & J.R. Shevock Schistidium squarrosum is readily distinguished from most species of Schistidium by the usually abruptly narrowed, ovate-lanceolate, often curved or falcate leaves, lacking or with very short awns, 2(-3) stratose upper leaf laminae, and large, tapering, broadly ovate-lanceolate or lanceolate perichaetial leaves. The perichaetial leaves are a useful field character as they tightly surround the capsule. Schistidium squarrosum is also viewed as a semi-rheophytic species occurring in habitats much like those described for S. splendens. However, some occurrences are in more exposed sites with less water flow such as sheet rock drainages or road banks. To date, Schistidium squarrosum is restricted to western North America, reported from California, Nevada, Oregon, and Washington. Schistidium cinclidodonteum appears closely related to S. squarrosum and is the species most likely to be confused with it. However, Schistidium cinclidodonteum is usually a larger plant having longer leaves (up to 5.0 mm) whereas leaves of S. squarrosum usually range from 2.2-2.8 mm, rarely longer (to 3.0 mm). An efficient way to separate the two species is by examining leaf apices. The leaf apex of S. squarrosum is channeled apically, in contrast to that of S. cinclidodonteum which ends in a terete apiculus.
Stability and resilience of conifer-dominated vegetation communities following clear-cutting and slash-burning in central British Columbia, were modeled across gradients of resource availability, fire return interval (FRI), and fire severity. We hypothesized that high resource availability and long fire-free intervals would enhance stability, whereas high resource availability and short fire-free intervals would confer resilience. Fire weather indices and pre- and post-burn fuel loads were recorded and vegetation regrowth monitored for 5-11 years at 12 sites. Stepwise regression was used to model rates of revegetation, increases in vascular species richness, and pre- and post-burn similarity of species composition as a function of the environmental variables. Predicted stability for four sub-boreal to subalpine vegetation communities with contrasting resource availability and FRI corresponded closely to our hypotheses. Rates of revegetation were more strongly correlated with resource availability, whereas composition-based response variables were more strongly correlated with the FRI. Based on revegetation rates, all ecosystems were predicted to have equal resilience. However, based on vegetation composition, mesic sub-boreal ecosystems were predicted to be more resilient than mesic subalpine ecosystems because the degree of change in species composition was less sensitive to increasing burn severity. More slash-burned sites with a broader range of burn severities are needed to verify these preliminary models.
Ginns, J. 2017. Polypores of British Columbia (Fungi: Basidiomycota). Ministry of Forests, Lands, and NR Operations, Technical Report 104. ISBN978-0-7726-7053-3 (Print version) & ISBN 978-0-7726-7054-0 (Digital version)
Abstract Nearly 200 species of polypores (Fungi: Basidiomycota) are accepted as part of the mycoflora of British Columbia, Canada. The lifestyle of the pathogenic polypores causes significant loss of timber value, especially in old-growth stands. The killing of trees affects species composition, stand density and structure, and the direction and rate of forest succession. Most polypores are saprobes and play a highly beneficial role by contributing to nutrient recycling through the decay of woody debris in forests. The rotted debris promotes growth of tree seedlings and other plants and increases the biodiversity of the forests.
A main purpose of this report is to ease the identification of polypore specimens through a step-by-step reduction of the number of probable names for an unnamed collection. This is accomplished in three ways. First, several series of comprehensive keys lead the user to names of genera and species. Next, the user compares their unnamed specimen with colour photographs of the basidiomata. Finally, the user confirms the identification with a detailed account of each genus or species that includes its known habitats and geographical distribution. The description emphasizes features of fresh basidiomata, such as condition, colour, and size, and also notes critical microscopic characters.
Digital version is available from: https://www.for.gov.bc.ca/hfd/pubs/docs/TR/TR104.pdf
Three Biologist positions (03 level) are advertised in the links below for: 1) herbaria manager (DAO & DAOM) in Ottawa, ON; 2) the Canadian Collection of Fungal Cultures (CCFC) in Ottawa, ON; and 3) the Canadian Clonal Genebank (CCGB) in Harrow, ON - all in Canada.
For anyone interested please go to the link to apply: https://emploisfp-psjobs.cfp-psc.gc.ca/psrs-srfp/applicant/page1800?poster=1022603&toggleLanguage=e
Send submissions to firstname.lastname@example.org
BEN is archived at http://www.ou.edu/cas/botany-micro/ben/