Effects of fire radiative energy density dose on Pinus contorta and Larix occidentalis seedling physiology and mortality

2017 ◽  
Vol 26 (1) ◽  
pp. 82 ◽  
Author(s):  
Alistair M. S. Smith ◽  
Alan F. Talhelm ◽  
Daniel M. Johnson ◽  
Aaron M. Sparks ◽  
Crystal A. Kolden ◽  
...  
Keyword(s):  
Energy Density ◽  
Pinus Contorta ◽  
Heat Waves ◽  
Radiative Energy ◽  
Seedling Mortality ◽  
Larix Occidentalis ◽  
Seedling Physiology ◽  
General Decline ◽  
Combustion Properties ◽  
Leaf Level

Climate change is projected to exacerbate the intensity of heat waves and drought, leading to a greater incidence of large and high-intensity wildfires in forested ecosystems. Predicting responses of seedlings to such fires requires a process-based understanding of how the energy released during fires affects plant physiology and mortality. Understanding what fire ‘doses’ cause seedling mortality is important for maintaining grasslands or promoting establishment of desirable plant species. We conducted controlled laboratory combustion experiments on replicates of well-watered nursery-grown seedlings. We evaluated the growth, mortality and physiological response of Larix occidentalis and Pinus contorta seedlings to increasing fire radiative energy density (FRED) doses created using natural fuels with known combustion properties. We observed a general decline in the size and physiological performance of both species that scaled with increasing FRED dose, including decreases in leaf-level photosynthesis, seedling leaf area and diameter at root collar. Greater FRED dose increased the recovery time of chlorophyll fluorescence in the remaining needles. This study provides preliminary data on what level of FRED causes mortality in these two species, which can aid land managers in identifying strategies to maintain (or eliminate) woody seedlings of interest.

Black Bear Damage to Thinned Timber Stands in Northwest Montana

1989 ◽  
Vol 4 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Andrew C. Mason ◽  
David L. Adams
Keyword(s):  
Pinus Contorta ◽  
Black Bear ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Abies Lasiocarpa ◽  
Pinus Monticola ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Engelmann Spruce ◽  
Northwest Montana

Abstract Bear damage was at least five times higher in thinned blocks than in adjacent unthinned blocks of western larch (Larix occidentalis), lodgepole pine (Pinus contorta), and Engelmann spruce (Picea engelmannii) on the Kootenai National Forest in northwest Montana. Western larch suffered the greatest damage (63% of all trees damaged and 92% of the trees killed). Damaged larch ranged from 4 to 13 in. dbh; the 4 to 8-in. dbh class accounted for 85% of the damage. Douglas-fir (Pseudotsuga menziesii), western redcedar (Thuja plicata), subalpine fir (Abies lasiocarpa), western white pine (Pinus monticola), and western hemlock (Tsuga heterophylla) were not damaged. Stand projections showed up to a 17% reduction in board-foot yield from bear damage, after 50 years, compared with hypothetical undamaged stands. West. J. Appl. For. 4(1):10-13, January 1989.

scholarly journals Larch Seed Trees Sustain Arboreal Lichens and Encourage Recolonization of Regenerating Stands

2007 ◽  
Vol 22 (2) ◽  
pp. 94-98 ◽  
Author(s):  
Fred L. Bunnell ◽  
Trevor Goward ◽  
Isabelle Houde ◽  
Curtis Björk
Keyword(s):  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Road Dust ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Source Tree ◽  
Winter Food ◽  
The Difference

Abstract In many areas Bryoria lichen is a major winter food for deer and caribou. We examined the role of western larch (Larix occidentalis) seed trees in retaining arboreal lichens and encouraging recolonization of regenerating stands by Bryoria. Although exposed to desiccation, Bryoria was sustained in significant amounts in larch seed trees. Other than a reduction near roads, apparently by alkaline road dust, arboreal forage lichens were relatively uniformly distributed throughout the regenerating stands. There was little difference in abundance up to 135 m from the source tree. The sorediate form of the lichens did better on lodgepole pine (Pinus contorta), and larger, nonsorediate fragments were more abundant on western larch. We attribute the difference to bark pH. Scattered western larch seed trees were effective at retaining lichens and facilitating recolonization of the regenerating stand.

Interactive effects of light and stratification on the germination of some British Columbia conifers

1994 ◽  
Vol 72 (11) ◽  
pp. 1635-1646 ◽  
Author(s):  
X. J. Li ◽  
P. J. Burton ◽  
C. L. Leadem
Keyword(s):  
British Columbia ◽  
Seed Germination ◽  
Pseudotsuga Menziesii ◽  
Seed Weight ◽  
Pinus Contorta ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Pinus Monticola ◽  
Larix Occidentalis ◽  
Tree Seed

Pregermination stratification treatment was generally more important than the effects of light on seed germination by 14 conifer species and varieties native to British Columbia. Nevertheless, there were some strong species differences in the response of germination to light. Final germination percentage after 21 days (28 days for Abies spp.) for both stratified and unstratified seeds of Picea glauca, Picea sitchensis, and Tsuga heterophylla showed no response to light during germination. Seed germination by Abies grandis, Pinus contorta var. contorta, Pinus contorta var. latifolia, Pinus ponderosa, Pseudotsuga menziesii var. glauca, and Pseudotsuga menziesii var. menziesii responded positively to light if unstratified but was not significantly affected by light when stratified. For Thuja plicata seeds, germination responded positively to light regardless of stratification pretreatment. Light appeared to reduce germination of stratified seeds of Abies amabilis, Abies lasiocarpa, Larix occidentalis, and Pinus monticola, although stratification conditions for these species were suboptimal. The germination rate of stratified seeds of all species and unstratified seeds of most species was increased by light. Results showed no significant relationship between germination response to light and shade-tolerance ranking or mean seed weight of the species. In six seed lots of Pinus contorta var. latifolia, however, we detected a weak negative correlation between mean seed weight and unstratified light responsivity measured after 1 week but a significant positive correlation when measured after 3 weeks. Very low light levels in closed-canopy forests or in the forest floor may prolong tree seed germination but are unlikely to constrain final germination levels after most seeds have been naturally stratified by moist, cool winter conditions. The importance of differences in the rate and timing of tree seed germination under natural conditions remains to be demonstrated. Key words: conifer biology, forest regeneration, light response, lodgepole pine, Pinus contorta, seed germination, stratification.

Measurements relating fire radiative energy density and surface fuel consumption – RxCADRE 2011 and 2012

2016 ◽  
Vol 25 (1) ◽  
pp. 25 ◽  
Author(s):  
Andrew T. Hudak ◽  
Matthew B. Dickinson ◽  
Benjamin C. Bright ◽  
Robert L. Kremens ◽  
E. Louise Loudermilk ◽  
...  
Keyword(s):  
Energy Density ◽  
Fuel Consumption ◽  
Airborne Lidar ◽  
Radiative Energy ◽  
Small Scale ◽  
Power Flux ◽  
Fuel Loads ◽  
Fire Modelling ◽  
Before And After ◽  
Radiometric Signal

Small-scale experiments have demonstrated that fire radiative energy is linearly related to fuel combusted but such a relationship has not been shown at the landscape level of prescribed fires. This paper presents field and remotely sensed measures of pre-fire fuel loads, consumption, fire radiative energy density (FRED) and fire radiative power flux density (FRFD), from which FRED is integrated, across forested and non-forested RxCADRE 2011 and 2012 burn blocks. Airborne longwave infrared (LWIR) image time series were calibrated to FRFD and integrated to provide FRED. Surface fuel loads measured in clip sample plots were predicted across burn blocks from airborne lidar-derived metrics. Maps of surface fuels and FRED were corrected for occlusion of the radiometric signal by the overstorey canopy in the forested blocks, and FRED maps were further corrected for temporal and spatial undersampling of FRFD. Fuel consumption predicted from FRED derived from both airborne LWIR imagery and various ground validation sensors approached a linear relationship with observed fuel consumption, which matched our expectation. These field, airborne lidar and LWIR image datasets, both before and after calibrations and corrections have been applied, will be made publicly available from a permanent archive for further analysis and to facilitate fire modelling.

scholarly journals Climate, radial growth, and mortality associated with conifer regeneration infected by root disease (Armillaria ostoyae)

2021 ◽  
Vol 97 (01) ◽  
pp. 43-51
Author(s):  
Michael P. Murray ◽  
Adrian Leslie
Keyword(s):  
Pseudotsuga Menziesii ◽  
Radial Growth ◽  
Pinus Contorta ◽  
Mortality Rates ◽  
Root Disease ◽  
Economic Systems ◽  
Larix Occidentalis ◽  
Mortality Trends ◽  
Armillaria Ostoyae ◽  
Annual Mortality

Tree root disease caused by the pathogen Armillaria ostoyae (Romagn.) Herink has notable influence on bio-economic systems of southern British Columbia (BC) and the northwestern United States. Annual radial growth and mortality trends of regeneration associated with A. ostoyae during the first 21 years of a plantation were investigated. Our dendrochronological approach focused on a plantation established in 1991 with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western larch (Larix occidentalis Nutt.), and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm. ex S. Wats.). We examined tree rings for reduced growth onset (RGO) to estimate infection periods. Among trees studied, we found that the number of RGO events peaked in 2006 followed by a steady decline in frequency. A similar trend was seen in annual mortality rates which reached maximum values in 2007 followed by an uninterrupted decrease. The average number of years from RGO to death based on host species ranged from 2.3 to 3.6 years. According to on logistic regression modeling, values associated with drought codes and duff moisture codes were significant in determining the year of death for infected trees. The predicted increase in frequency of summer droughts may lead to elevated mortality associated with A. ostoyae in young plantations.

Inonotus weirii. [Descriptions of Fungi and Bacteria].

1972 ◽  
Author(s):  
D. N. Pegler
Keyword(s):  
Geographical Distribution ◽  
Pinus Contorta ◽  
Tsuga Heterophylla ◽  
Picea Engelmannii ◽  
Thuja Plicata ◽  
Western Canada ◽  
Larix Occidentalis ◽  
Ring Rot ◽  
Infected Material ◽  
Root Contact

Abstract A description is provided for Inonotus weirii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Abies amabilis, A. grandis, A. lasiocarpa, Chamaecyparis spp., Larix occidentalis, Picea engelmannii, P. sitchensis, Pinus contorta, P. monticola, P. ponderosa, Pseudotsuga menziesii, Thuja plicata, Tsuga heterophylla. DISEASE: Laminated butt rot and yellow ring rot of conifers. GEOGRAPHICAL DISTRIBUTION: North America (Western Canada, Oregon, Washington); Japan. TRANSMISSION: The disease is spread by root contact with infected material in the soil; there appears to be little spread of the fungus by growth through the soil. It is likely that infection of freshly exposed wounds takes place through airborne basidiospores.

Are mixed-species stands more productive than single-species stands: an empirical test of three forest types in British Columbia and Alberta

2003 ◽  
Vol 33 (7) ◽  
pp. 1227-1237 ◽  
Author(s):  
H YH Chen ◽  
K Klinka ◽  
A -H Mathey ◽  
X Wang ◽  
P Varga ◽  
...  
Keyword(s):  
Pinus Contorta ◽  
Black Spruce ◽  
Lodgepole Pine ◽  
Empirical Test ◽  
Single Species ◽  
Growth Patterns ◽  
Thuja Plicata ◽  
Larix Occidentalis ◽  
Mixed Species ◽  
Stand Volume

Stand volumes were determined for naturally established, even-aged, single- and mixed-species stands involving three combinations of shade-tolerant and shade-intolerant conifers on similar sites: (i) western redcedar – western hemlock (Thuja plicata Donn ex D. Don – Tsuga heterophylla (Raf.) Sarg.), (ii) lodgepole pine – western larch (Pinus contorta Dougl. ex Loud. – Larix occidentalis Nutt.), and (iii) lodgepole pine – black spruce (Pinus contorta – Picea mariana (Mill.) BSP). Stand volume was significantly increased with site index and breast-height age in all three studies. Stand volume was also related to relative stand density in the lodgepole pine – black spruce study. When both species were shade tolerant (hemlock–redcedar), stand volume increased linearly with the proportion of hemlock; the mixed-species stands had intermediate volume compared with single-species stands. The combination of two shade-intolerant species (pine–larch) had lower stand volume than that anticipated from single-species stands, implying that one species may inhibiting the growth of the other. Mixtures of shade-intolerant and shade-tolerant species with different growth patterns (spruce–pine) may be more productive than single-species stands in specific ecological contexts and developmental stages. The effect of one species on the productivity of another species is tree-species and site specific: at maturity, even-aged, mixed-species coniferous stands are not necessarily more productive than single-species stands.

scholarly journals Height:Diameter Ratios and Stability Relationships for Four Northern Rocky Mountain Tree Species

2001 ◽  
Vol 16 (2) ◽  
pp. 87-94 ◽  
Author(s):  
Hagan T. Wonn ◽  
Kevin L. O'Hara
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Pinus Contorta ◽  
Tree Height ◽  
Growth And Yield ◽  
Storm Damage ◽  
Species Trees ◽  
Larix Occidentalis ◽  
Yield Model ◽  
Wind Events

Abstract Ratios of tree height to diameter have been used to predict susceptibility to storm damage for many years. In this study, individual trees damaged by recent snow and wind events in western Montana were sampled in 1997 and 1998 to determine their height:diameter ratios in comparison to nearby undamaged trees. Four species were sampled: ponderosa pine (Pinus ponderosa), western larch (Larix occidentalis), interior Douglas-fir (Pseudotsuga menziesii var. glauca), and lodgepole pine (Pinus contorta var. latifolia). Ratios of 80:1 (both measures in equal units) provided a stability threshold for all four species. Trees with higher ratios were more prone to damage than trees with lower ratios. Height:diameter ratios from trees grown in spacing trials were used to examine spacings that avoided development of unstable trees. Wide spacings or early thinnings provide the best means of avoiding major losses to snow and wind damage. The growth and yield model Prognosis was unable to predict height:diameter ratios for developing stands. West. J. Appl. For. 16(2):87–94.

scholarly journals A FLAT SPACETIME MODEL OF THE UNIVERSE

2012 ◽  
Vol 27 (36) ◽  
pp. 1250201 ◽  
Author(s):  
PANKAJ JAIN
Keyword(s):  
Energy Density ◽  
Big Bang ◽  
Initial Singularity ◽  
Radiative Energy ◽  
Flat Spacetime ◽  
Spacetime Metric ◽  
Radiative Temperature ◽  
Big Bang Model ◽  
The Masses ◽  
The Universe

We propose a model of the Universe based on Minkowski flat spacetime metric. In this model the spacetime does not evolve. Instead the matter evolves such that all the mass parameters increase with time. We construct a model based on unimodular gravity to show how this can be accomplished within the framework of flat spacetime. We show that the model predicts the Hubble law if the masses increase with time. Furthermore, we show that it fits the high z supernova data in a manner almost identical to the standard Big Bang model. Furthermore, we show that at early times the Universe is dominated by radiative energy density. The phenomenon of recombination also arises in our model and hence predicts the existence of CMBR. However, a major difference with respect to the standard Big Bang is that there is no initial singularity and the radiative temperature and energy density do not evolve in our model. Furthermore, we argue that the basic motivation for inflation is absent in our model.

Pruning Costs for Four Northern Rocky Mountain Species with Three Equipment Combinations

1995 ◽  
Vol 10 (2) ◽  
pp. 59-65 ◽  
Author(s):  
Kevin L. O'Hara ◽  
Darin A. Larvik ◽  
Narayanan I. Valappil
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Pinus Contorta ◽  
Rocky Mountain ◽  
Ease Of Use ◽  
Larix Occidentalis ◽  
Time And Motion ◽  
Motion Study ◽  
Grading Standards ◽  
The Cost

Abstract A time and motion study was conducted to determine the cost to prune ponderosa pine (Pinus ponderosa), interior Douglas-fir (Pseudotsuga menziesii var. glauca), western larch (Larix occidentalis), and lodgepole pine (Pinus contorta) with loppers, pole saws, and Power Pruners. Costs to prune up to 8 ft ranged from $0.61 to $2.35/tree, and from $2.34 to $6.42/tree to prune to 18 ft depending upon species, equipment, and wage assumptions. Pole saws were the recommended equipment based on cost, ease of use, and damage to trees. Multivariate models were unable to explain much variation in pruning time because of the confounding effects of so many variables. Results suggest more than three trees could be pruned to a height of 9 ft for the same cost as pruning one tree to 18 ft. Pruning more trees to a 9 ft height would therefore increase clearwood production overpruning fewer trees to 18 ft, but may necessitate some modification of current log grading standards. West. J. Appl. For. 10(2):59-65.

Sign in / Sign up

Export Citation Format

Share Document