Origin of Symphyotrichum anticostense (Asteraceae: Astereae), an endemic, high polyploid species of the Gulf of St. Lawrence region, based on morphological and nrDNA evidence

Symphyotrichum anticostense (Fernald) G.L.Nesom (Asteraceae: Astereae), a rare endemic of the Gulf of St. Lawrence region is a high allopolyploid (2n=10x=80). It has been hypothesized to be derived from the hybrid between tetraploid (2n=4x=32) individuals of S. boreale (Torr. & A.Gray) Löve & Löve and the hexaploid (2n=6x=48) S. novi-belgii (L.) G.L.Nesom. We investigated this hypothesis using morphological and molecular ITS-sequence data, and we tried to determine the potentially geographic origins of the taxon. Univariate morphological analyses show that 67.5% of the S. anticostense characters are parent-like, 43.5% from S. novi-belgii and 13% from S. boreale, the remainder not differing statistically from either parent; 23.5% are intermediate; and 9% transgressive. Multivariate analyses show that S. anticostense is intermediate between its putative parents. The molecular results support the morphological data, but due to the insufficient resolution among ribotypes on the tree, a more rapidly evolving marker will be needed to ascertain more reliably the origin of S. anticostense. Besides the hypothesis of genetic drift and allele fixation following long-distance dispersals, at least three independent geographic origins may be suggested for S. anticostense; Anticosti Island, Lake St. John, and Gaspé Peninsula-New Brunswick-Maine.

The biota of Canada: checklist of the centipedes of Canada (Myriapoda: Chilopoda)

The centipede fauna of Canada is reviewed based on information available in the literature and on examination of some material, and provincial and territorial distributions are provided. About 53 species are known from Canada, representing four orders: Scutigeromorpha (1), Scolopendromorpha (5), Geophilomorpha (19), and Lithobiomorpha (28). British Columbia has the most recorded species (23), followed by Ontario (17) and Newfoundland and Labrador (12). Arctogeophilus glacialis (Attems) and Alaskobius adlatus Chamberlin are newly reported from Canada (Northwest Territories), Schendyla nemorensis (Koch) is newly reported from Ontario, and Lithobius forficatus (Linnaeus) is recorded for the first time from New Brunswick and Prince Edward Island. Arctogeophilus melanonotus (Wood) is removed from the list of Canadian species.

Is Forensic Entomology Lost in Space?

Spatial and scale effects have barely been considered in forensic entomology, despite their pervasive influence on most of the parameters affecting the development of insect larval stages and the progression of insect succession on cadavers. Here, we used smoothing/interpolation techniques and semivariograms to document the spatial dynamics of sarcosaprophageous Calliphoridae, an important forensic taxon, in the Greater Moncton area in New Brunswick, Canada. Results indicated that the spatial dynamics of Calliphoridae differed between species, some species showing strong patterns of regional aggregation while others did not. Multivariate spatial correlations indicated that interspecific relationships in space varied widely, ranging from local and large-scale aggregation to spatial anticorrelation between species. Overall, this study suggested that even within a restricted timescale, the spatial dynamics of Calliphoridae can operate at many scales, manifest in different patterns, and be attributed to multiple different causes. We stress that forensic entomology has much to benefit from the use of spatial analysis because many important forensic questions, both at the fundamental and practical levels, require a spatial solution.

Exploring the Recruitment Dynamics of Sugar Maple and Yellow Birch Saplings into Merchantable Stems Following Harvesting in the Acadian Forest Region of New Brunswick, Canada

The recruitment of saplings in forest stands into merchantable stems is a very complex process, thus making it challenging to understand and predict. The recruitment dynamics in the Acadian Forest Region of New Brunswick are not well known or documented. Our objective was to draw an inference from existing large scale routine forest inventories as to the different dynamics behind the recruitment from the sapling layer into the commercial tree size layer in terms of density and occurrence of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britt.) following harvesting, by looking at many factors on a wide range of spatial and temporal scales using models. Results suggest that the variation in density and probability of occurrence is best explained by the intensity of silvicultural treatment, by the merchantable stem density in each plot, and by the proportion of merchantable basal area of each group of species. The number of recruits of sugar maple and yellow birch stems tend be higher when time since last treatment increases, when mid to low levels of silvicultural treatment intensity were implemented, and within plots having intermediate levels of merchantable stem density. Lastly, our modeling efforts suggest that the probability of occurrence and density of recruitment of both species tend to increase while its share of merchantable basal area increases.