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.

Toward a new arctic vegetation map: a review of existing maps

Abstract: Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA; Fax +1 303 492 6388; E-mailDONALD.WALKER@COLORADO.EDU; Botanical Museum, University of Copenhagen, Gothersgade 130, DK-1123, Copenhagen, Denmark; Fax +45 35 32 22 10; Institut fur Okologie der Pflamen, Westfalische-Wilhelms-Universitädt, Hindenburgplatz 55, D-48143 Miinster, Germany; Fax +49 251 838371; Icelandic Museum of Natural History, Hiemmur 3, P.O. Box 5320, IS-125 Reykjavik, Iceland; Fax +354 1 620815; institute of Biology and Geology, Troms^ University, N-9037 Troms0, Norway; Fax +47 77 645600; ^ORUT Group Ltd., N-9005 Troms0, Norway; Tel. +47 776 80150; ^Faculty of Geography, Moscow State University, Moscow 119899, Russia; Fax +7 095 932 8836; University of Alaska Museum, Fairbanks, AK 99775-6960, USA; Fax +1 907 474 5469; ^U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, AK 99503, USA; Fax +1 907 786 3635; ^Komarov Botanical Institute, 197376 Russia, St. Peterburg, ul. Prof. Popova 2; Fax +7 812 234 4512; ^Canadian Forest Service, Northern Forestry Centre, 5320 122 Street, Edmonton, Alberta, Canada T6H3S5; Fax +1 403 435 7359

Variable retention harvest of white spruce stands and saproxylic beetle assemblages

Abstract: Dead wood dependent (saproxylic) insects have been identified as vulnerable to the effects of modern forestry practices. We examined the effects of variable retention harvesting on saproxylic beetle assemblages. Variable retention of living green trees seeks to leave more forest structure on the landscape with the goal of maintaining ecosystem function and biodiversity. Ninety flight-intercept traps were divided between recently dead natural snags and snags killed by gir- dling in three replicated forest stands with 10%, 20%, 50%, and 75% residual structure and in uncut control stands. Beetles were collected and identified during the second and third summers post harvest and grouped for analyses as (i) wood- and bark-borers, (ii) fungivores, and (iii) predators. Harvesting intensity explained a relatively small amount of the variability in the beetle assemblages. However, all groups responded strongly to coarse woody debris variables and especially to snag decay class during the third postharvest summer, suggesting that factors associated with coarse woody debris quality and quantity determine the initial responses and successional trajectories of saproxylic beetle assemblages. The main effects of variable retention on saproxylic assemblages are expected to be mediated through differences in amount of coarse woody debris expected to materialize with the death and decay of green trees left as residual elements.

Modelling and mapping permafrost at high spatial resolution using Landsat and Radarsat-2 images in Northern Ontario, Canada: Part 2 – regional mapping

Abstract: Permafrost occurs mainly at high latitudes and is currently subjected to widespread thawing due to global warming, which has significant ecological and socio-economic impacts. One way to map permafrost condition and its change at high spatial resolution is to calculate soil temperatures using a process-based permafrost model, such as the Northern Ecosystem Soil Temperature NEST model, based on remote-sensing data. In a previous paper Ou et al. 2015, we showed that the NEST model can be used to model soil temperatures, frozen depth, and active layer thickness in a warm and discontinuous permafrost area that is located in the Hudson Bay Lowlands in northern Ontario, Canada. In this article, we applied the model over the whole study area to map the distribution of permafrost conditions and their changes from the 1960s to the 2000s at high spatial resolution. Some of the model inputs were estimated based on land-cover and surficial material maps derived from Landsat-5 TM and Radarsat-2 SAR C-HH and C-HV images. By comparison to field observations, we were able to achieve an average mapping accuracy of 99% for both the land-cover and surficial material maps, when both Landsat and Radarsat-2 images were used. In addition, all the 49 field-observed treed and shrub permafrost landform sites found in the study area were correctly identified on the classified image. This spatial modelling study shows that permafrost currently underlies about 9.4% of the land in this area, and varies significantly among land-cover types. With the increases in mean annual air temperature 1.9°C and precipitation 2.4% from the 1960s to the 2000s, the model results show a deepening of active layer by 20.5%. However, the permafrost has persisted in most of the area due to the protection of thick peat. The modelled permafrost extent reduced only from 9.8% to 9.4%.