Canadian Forest Service

About: Canadian Forest Service is a government organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Taiga. The organization has 794 authors who have published 1259 publications receiving 63889 citations. The organization is also known as: CFS.

Effects of seed water content and storage temperature on the germination parameters of white spruce, black spruce and lodgepole pine seed

Abstract: The effect of seed water content (WC) (2–3, 5–6 and 22–25%, on a fresh weight basis), storage temperature (+4, −20, −80 and −196°C) and storage duration (6, 12, 24, 48 and 60 months) on the germination of white spruce (Picea glauca (Moench) Voss), black spruce (Picea mariana (Mill.) B.S.P.) and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) seed was investigated. Germination of white spruce control (untreated) seeds and seeds adjusted to 2–3% and 5–6% WC declined after 48 months of storage at −80 and −196°C, with a further decline at 60 months at −20, −80, −196°C. Germination remained high when control white spruce seeds and seeds with 2–3, 5–6% WC were stored at +4°C, over all storage durations. Generally, black spruce and lodgepole pine exhibited high germination at all storage temperatures at 2–3% and 5–6% WC as well as the control (untreated) seed, for up to 60 months in storage. Germination declined for all three species when seed was conditioned to 22–25% WC. This loss in germination was partially recovered in white spruce seed stored at +4, −20 and −80°C after storage durations of 24, 12 and 48 months, respectively, and in black spruce seeds stored at −20 and −196°C after storage durations of 24 months. Mean germination time (MGT) was relatively constant for all species, under all conditions, except for seed conditioned to 22–25% WC, where MGT increased for white spruce seed stored 48 months at −80 and −196°C, and for black spruce seed stored 24 months at +4 and −80°C and 60 months at −196°C. These results show that the optimal storage temperatures are 4°C for white spruce, and 4, −20, −80, and −196°C for black spruce and lodgepole pine, and 2–6% water content is optimal for all 3 species at these temperatures.

Randomly Amplified Polymorphic DNA Evidence of Introgression in Two Closely Related Sympatric Species of Coniferophagous Choristoneura (Lepidoptera: Tortricidae) in Atlantic Canada

Abstract: DNA was extracted from selected desiccated museum specimens of Choristoneura fumiferana (Clemens) and C. pinus Freeman and analyzed by using the randomly amplified poly- morphic DNA (RAPD) technique. Seventeen species-specific RAPD markers were used to differ- entiate between these 2 closely related and morphologically similar budworm species. Several morphologically atypical specimens of each budworm species were selected for analysis based on deviations from conventional descriptions of uncus shape and size, wing bands, maculation, and background coloration. Analysis of the distribution of species-specific markers in selected specimens from Atlantic Canada, where the 2 species are sympatric and their flight periods occasionally overlap, suggests that reproductive isolation of these 2 Choristoneura species is incomplete, thus providing the first evidence that hybridization of C. fumiferana and C. pinus has occurred in nature. The significance of these results to hybridization, introgression and retained ancestral polymorphism is discussed.

Dissimilar bacterial and fungal decomposer communities across rich to poor fen peatlands exhibit functional redundancy

Abstract: Haynes, K. M., Preston, M. D., McLaughlin, J. W., Webster, K. and Basiliko, N. 2015. Dissimilar bacterial and fungal decomposer communities across rich to poor fen peatlands exhibit functional redundancy. Can. J. Soil Sci. 95: 219–230. Climatic and environmental changes can lead to shifts in the dominant vegetation communities present in northern peatland ecosystems, including from Sphagnum- to vascular-dominated systems. Such shifts in vegetation result in changes to the chemical quality of carbon substrates for soil microbial decomposers, with leaves and roots deposited in the peat surface and subsurface that potentially decompose faster. This study characterized the bacterial and fungal communities present along a nutrient gradient ranging from rich to poor fen peatlands and assessed the metabolic potential of these communities to mineralize a variety of organic matter substrates of varying chemical complexity using substrate-induced respiration (SIR) assays. Distinct microbial communities existed betw...