Tree and stand structure of the non-native Pinus contorta in relation to native Pinus sylvestris and Picea abies in young managed forests in boreal Sweden

2017 ◽  
Vol 33 (3) ◽  
pp. 245-254
Author(s):  
Sofia Bäcklund ◽  
Mari Jönsson ◽  
Joachim Strengbom ◽  
Göran Thor
Keyword(s):  
Picea Abies ◽  
Pinus Sylvestris ◽  
Pinus Contorta ◽  
Stand Structure ◽  
Managed Forests

Impact of stand structure on surface fire ignition potential in Picea abies and Pinus sylvestris forests in southern Finland

2005 ◽  
Vol 35 (2) ◽  
pp. 410-420 ◽  
Author(s):  
Heidi Tanskanen ◽  
Ari Venäläinen ◽  
Pasi Puttonen ◽  
Anders Granström
Keyword(s):  
Picea Abies ◽  
Pinus Sylvestris ◽  
Stand Structure ◽  
Weather Data ◽  
Stand Age ◽  
Small Scale ◽  
Age Classes ◽  
Area Index ◽  
Fire Weather Index ◽  
Fire Ignition

Forest fire ignition potential was investigated in Picea abies (L.) Karst. (Norway spruce) and Pinus sylvestris L. (Scots pine) dominated stands of 0, 15, 30–45, and 40–60 years of age. A series of small-scale (<0.5 m2) ignition tests were carried out in experimental plots on 61 different days in June, July, and August. Ignition success percentages were analyzed in relation to stand structural properties, preclassified stand types, and the output of the Canadian Fire Weather Index system. In addition, the number of average stand-type-specific fire days was estimated based on weather data (June–August) for southern Finland for the years 1991–2002. Factors in stand structure that significantly correlated with the ignition success percentage were canopy depth and leaf area index, the correlation coefficients being –0.575 (p < 0.005) and –0.582 (p < 0.005), respectively. In Pinus sylvestris dominated stands, ignition tests produced self-sustained surface fires in 32.0%, 24.0%, and 19.3% of cases in 0-, 15-, and 30- to 45-year age classes, respectively. In Picea abies dominated sites conditions were favorable for fire in 12.0% and 4.6% of trials in the 0- and 40- to 60-year age classes, respectively. The output of the FWI-system correlated well with the ignition success in June and July but poorly in August. Based on the 12-year time series analysis, there were on average per year 27, 18, and 14 potential fire days in 0-, 15-, and 30- to 45-year-old Pinus sylvestris stands, and 10 and 4 potential fire days in 0- and 40- to 60-year-old Picea abies stands, respectively. We concluded that the dominance of Picea abies or Pinus sylvestris and stand age appear to modify the ignition conditions significantly and should be used as threshold indicators in fire occurrence predictions.

scholarly journals Silviculture and Wildlife: Snowshoe Hare Abundance across a Successional Sequence of Natural and Intensively Managed Forests

ISRN Ecology ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Druscilla S. Sullivan ◽  
Pontus M. F. Lindgren ◽  
Douglas B. Ransome
Keyword(s):  
Habitat Use ◽  
Pinus Contorta ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Bimodal Distribution ◽  
Managed Forests ◽  
Old Growth ◽  
South Central ◽  
Intensively Managed ◽  
Stand Attributes

We tested the hypotheses H1 that relative habitat use by snowshoe hares (Lepus americanus) would have a bimodal distribution with the highest abundance in young lodgepole pine (Pinus contorta) stands (both managed and unmanaged), minimal numbers in mature forests, and moderate abundance in old-growth forests and H2 that habitat use would increase in response to enhanced stand attributes from PCT (precommercial thinning) and fertilization treatments. Habitat use was measured by counts of fecal pellets of hares from 1999 to 2003 in forest stands in south-central British Columbia, Canada. Our results did not support the bimodal distribution of hares among coniferous stands, such that old-growth stands, at least in our region, do not provide sufficient habitat for hare populations. High-density (5000 to 13000 stems/ha) unthinned young lodgepole pine stands provide optimum habitat for hares in terms of overstory and stand structure. Thinned and fertilized stands may also provide habitat, particularly at densities ≤1000 stems/ha, and over time as understory conifers develop. Managed stands provided habitat for hares at the same level as mature stands, at 6–10 years after PCT. Maintenance of a range of managed and unmanaged stands in a landscape mosaic would be ideal for integration of silvicultural and wildlife management goals.

Xerotrema megalosporum. [Descriptions of Fungi and Bacteria].

2018 ◽  
Author(s):  
D. W. Minter
Keyword(s):  
British Columbia ◽  
Picea Abies ◽  
Pinus Sylvestris ◽  
Geographical Distribution ◽  
Pseudotsuga Menziesii ◽  
Pinus Contorta ◽  
Conservation Status ◽  
Taxus Baccata ◽  
Irish Republic

Abstract A description is provided for Xerotrema megalosporum, found on whitened old bare wood. Some information on its morphology, dispersal and transmission and conservation status is given, along with details of its geographical distribution (Canada (British Columbia), USA (Oregon, Washington), Greece, Irish Republic, Norway and UK) and hosts (Abies sp., Arctostaphylos sp., Picea abies, Pinus contorta, Pinus heldreichii, Pinus sylvestris, Pinus sp., Pseudotsuga menziesii and Taxus baccata).

Forest structure altered by mountain pine beetle outbreaks affects subsequent attack in a Wyoming lodgepole pine forest, USA

2011 ◽  
Vol 41 (12) ◽  
pp. 2403-2412 ◽  
Author(s):  
Daniel M. Kashian ◽  
Rebecca M. Jackson ◽  
Heather D. Lyons
Keyword(s):  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Climate Change Scenarios ◽  
Cone Production ◽  
Mountain Pine ◽  
Large Trees ◽  
Pine Beetle ◽  
The 1960S

Extensive outbreaks of the mountain pine beetle ( Dendroctonus ponderosae Hopkins) will alter the structure of many stands that will likely be attacked again before experiencing a stand-replacing fire. We examined a stand of lodgepole pine ( Pinus contorta var. latifolia Engelm. ex S. Watson) in Grand Teton National Park currently experiencing a moderate-level outbreak and previously attacked by mountain pine beetle in the 1960s. Consistent with published studies, tree diameter was the main predictor of beetle attack on a given tree, large trees were preferentially attacked, and tree vigor, age, and cone production were unimportant variables for beetle attack at epidemic levels. Small trees killed in the stand were killed based mainly on their proximity to large trees and were likely spatially aggregated with large trees as a result of the previous outbreak. We concluded that the driving factors of beetle attack and their spatial patterns are consistent across outbreak severities but that stand structure altered by the previous outbreak had implications for the current outbreaks in the same location. This study should catalyze additional research that examines how beetle-altered stand structure affects future outbreaks — an important priority for predicting their impacts under climate change scenarios that project increases in outbreak frequency and extent.

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