scholarly journals Trade-offs across densities and mixture proportions in lodgepole pine-hybrid spruce plantations

2021 ◽  
Vol 490 ◽  
pp. 119095
Author(s):  
Ignacio Barbeito ◽  
Bianca N.I. Eskelson ◽  
Grace Carsky
Keyword(s):  
Lodgepole Pine ◽  
Trade Offs ◽  
Hybrid Spruce

scholarly journals Manual Cutting of Sitka Alder-Dominated Plant Communities: Effects on Conifer Growth and Plant Community Structure

2004 ◽  
Vol 19 (4) ◽  
pp. 277-287 ◽  
Author(s):  
Suzanne W. Simard ◽  
Jean L. Heineman ◽  
Shannon M. Hagerman ◽  
W. Jean Mather ◽  
Donald L. Sachs
Keyword(s):  
Plant Community ◽  
Lodgepole Pine ◽  
Vascular Plant ◽  
Structural Diversity ◽  
Community Diversity ◽  
Limiting Factors ◽  
Growth And Survival ◽  
Montane Vegetation ◽  
Vegetation Complexes ◽  
Hybrid Spruce

Abstract Five-year growth and survival responses of lodgepole pine and hybrid spruce to manual cutting of Sitka alder were studied in two montane vegetation complexes in interior British Columbia. The effects of brushing on plant community diversity and structure also were examined. Alder cover and height were reduced throughout the 5-year posttreatment measurement period, but this had no effect on growth or survival of either 5- to 7-year-old lodgepole pine growing in the Dry Alder complex or 4- to 7-year-old hybrid spruce in the Wet Alder complex. Moderate alder cover, which was characteristic at these sites, did not appear to inhibit diameter growth of lodgepole pine or spruce. This was supported by competition thresholds for conifer diameter of 30 and 37% alder cover in the Dry Alder and Wet Alder complexes, respectively. In neither complex did manual cutting result in any changes in species richness, species diversity, or structural diversity of the vascular plant community. The results of this study suggest that brushing of Sitka alder is unnecessary for release of healthy lodgepole pine growing on mesic sites in the Dry Alder complex and is ineffective at alleviating growth limiting factors to spruce on Wet Alder sites. West. J. Appl. For. 19(4):277–287.

Forest fuels and potential fire behaviour 12 years after variable-retention harvest in lodgepole pine

2016 ◽  
Vol 25 (6) ◽  
pp. 633 ◽  
Author(s):  
Justin S. Crotteau ◽  
Christopher R. Keyes ◽  
Elaine K. Sutherland ◽  
David K. Wright ◽  
Joel M. Egan
Keyword(s):  
Lodgepole Pine ◽  
Structural Complexity ◽  
Fuel Load ◽  
Fire Behaviour ◽  
Forest Fuels ◽  
Fuel Loads ◽  
Variable Retention ◽  
Harvesting Technique ◽  
Trade Offs ◽  
Variable Retention Harvesting

Variable-retention harvesting in lodgepole pine offers an alternative to conventional, even-aged management. This harvesting technique promotes structural complexity and age-class diversity in residual stands and promotes resilience to disturbance. We examined fuel loads and potential fire behaviour 12 years after two modes of variable-retention harvesting (dispersed and aggregated retention patterns) crossed by post-harvest prescribed fire (burned or unburned) in central Montana. Results characterise 12-year post-treatment fuel loads. We found greater fuel load reduction in treated than untreated stands, namely in the 10- and 100-h classes (P = 0.002 and 0.049 respectively). Reductions in 1-h (P < 0.001), 10-h (P = 0.008) and 1000-h (P = 0.014) classes were greater in magnitude for unburned than burned treatments. Fire behaviour modelling incorporated the regenerating seedling cohort into the surface fuel complex. Our analysis indicates greater surface fireline intensity in treated than untreated stands (P < 0.001), and in unburned over burned stands (P = 0.001) in dry, windy weather. Although potential fire behaviour in treated stands is predicted to be more erratic, within-stand structural variability reduces probability of crown fire spread. Overall, results illustrate trade-offs between potential fire attributes that should be acknowledged with variable-retention harvesting.

Growth of planted lodgepole pine and hybrid spruce following chemical and manual vegetation control on a frost-prone site

1994 ◽  
Vol 24 (2) ◽  
pp. 208-216 ◽  
Author(s):  
Phil LePage ◽  
K. Dave Coates
Keyword(s):  
Control Method ◽  
Lodgepole Pine ◽  
Growing Season ◽  
Control Site ◽  
Response Threshold ◽  
Control Treatment ◽  
Poor Growth ◽  
Vegetation Control ◽  
And Control ◽  
Hybrid Spruce

The 5-year height and diameter growth response of a frost-tolerant species, (lodgepole pine, Pinuscontorta var. latifolia Dougl. ex Loud.) and a frost-susceptible species (hybrid spruce, Piceaglauca (Moench) Voss × Piceasitchensis (Bong.) Carr.) to different vegetation-control site-preparation treatment and timing combinations was examined using a factorial experiment. The site chosen for the experiment is subject to frequent summer growing season frosts. The vegetation control treatments were: an untreated control, manual cutting, and glyphosate applied at the rates of 1.4 and 2.1 kg active ingredient (a.i.) per hectare. Each vegetation-control treatment was applied at four dates (timing) that covered the active growing season of the vegetation on the study area. Vegetation-control method had a major impact on the growth of the planted seedlings. The influence of timing of control treatments on growth was found to be minor. Fifth-year height and diameter in the manual cutting and control treatments were equally poor. Growth was significantly improved by both levels of chemical vegetation control and after 5 years, no differences were apparent between the two. Pine height and diameter and spruce diameter continually improved as the level of thimbleberry (Rubusparviflorus Nutt.) was reduced. Below 5% thimbleberry cover, this growth increased dramatically, suggesting a response threshold. As vegetation cover was lowered, however, spruce seedlings were damaged by frost, resulting in reduced total height. In this case, better height growth was associated with either very low or moderately high thimbleberry cover than with moderate to low levels.

Testing for trade-offs between flight and reproduction in the mountain pine beetle (Coleoptera: Curculionidae) on two pine (Pinaceae) hosts

2019 ◽  
Vol 151 (3) ◽  
pp. 298-310 ◽  
Author(s):  
Asha Wijerathna ◽  
Caroline Whitehouse ◽  
Heather Proctor ◽  
Maya Evenden
Keyword(s):  
Pinus Banksiana ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Jack Pine ◽  
Tree Level ◽  
Offspring Sex Ratio ◽  
Individual Tree ◽  
Mountain Pine ◽  
Trade Offs ◽  
Pine Beetle

AbstractMountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), adults fly to disperse before host colonisation. The effect of flight on reproduction was tested by comparing the number and quality of offspring from beetles flown on flight mills to that of unflown control beetles. Beetles reproduced in bolts of their native host, lodgepole pine (Pinus contorta var. latifolia Engelmann (Pinaceae)), or a novel host, jack pine (Pinus banksiana Lambert (Pinaceae)). Bolts infested by control beetles produced more offspring overall than bolts with flown beetles. The effect of pine species on the number of offspring produced per bolt varied by individual tree. Flown adults produced fewer offspring compared to control parents in all bolts in jack pine regardless of the tree, but tree-level variation was visible in lodgepole pine. An interaction between flight treatment and tree host affected beetle body condition. More offspring emerged from jack pine, but higher quality offspring emerged from lodgepole pine. The offspring sex ratio was female-biased regardless of parental flight treatment. This study reveals trade-offs between flight and reproduction in mountain pine beetle as measured at the level of the bolt.

scholarly journals Site preparation severity influences lodgepole pine plant community composition, diversity, and succession over 25 years

2017 ◽  
Vol 47 (12) ◽  
pp. 1659-1671 ◽  
Author(s):  
Sybille Haeussler ◽  
Torsten Kaffanke ◽  
Jacob O. Boateng ◽  
John McClarnon ◽  
Lorne Bedford
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Management Practices ◽  
Lodgepole Pine ◽  
Site Preparation ◽  
Forest Composition ◽  
Plant Community Composition ◽  
Alternate Hosts ◽  
Trade Offs ◽  
Crown Closure

Lodgepole pine (Pinus contorta var. latifolia Engelm.) ecosystems of central British Columbia face cumulative stresses, and management practices are increasingly scrutinized. We addressed trade-offs between “light-on-the-land” versus more aggressive silvicultural approaches by examining plant communities and indicator species (non-natives, berry producers, epiphytes, mycotrophs, pine rust alternate hosts) across a gradient of five or six site preparation treatments at the Bednesti trial (established 1987). We tested whether more severe site preparation (i) caused plant community composition to diverge from a 35- to 46-year-old reference forest, (ii) accelerated succession by hastening crown closure, or (iii) delayed succession by promoting seral species. Nonmetric multidimensional scaling (NMDS) ordination showed all treatments converging toward the reference forest composition. At 10 years, succession was incrementally delayed by more severe treatments; at 25 years, only burned windrows were still delayed. Mixed-effects models based on site preparation severity were better than crown closure models for 11 of 13 variables tested, suggesting that mostly belowground processes drive succession in these infertile ecosystems. Invasive hawkweeds persisted on all treatments at 25 years. Limited, contradictory data did not support using mechanical or fire treatments to reduce alternate hosts of pine stem rusts. Long-term trials such as Bednesti highlight the need for ecosystem-specific strategies and diverse approaches to accommodate conflicting benefits and risks of disturbance in forests.

WHITEBARK PINE IN THE ROCKY MOUNTAINS OF ALBERTA

1967 ◽  
Vol 43 (3) ◽  
pp. 278-284 ◽  
Author(s):  
R. J. Day
Keyword(s):  
Rocky Mountains ◽  
Lodgepole Pine ◽  
Fire Frequency ◽  
Whitebark Pine ◽  
South West ◽  
Excellent Growth ◽  
Spruce Stands ◽  
Pine Lumber ◽  
Commercial Size ◽  
Hybrid Spruce

Whitebark pine has been described by most authorities as a small commercially valueless tree usually found at timberline. Whitebark pine of exceptionally large commercial size forms an interesting component of some of the lodgepole pine - hybrid spruce stands in the subalpine forests of south-west Alberta. Because of a high commercial value many of these large specimens have already been used for the manufacture of "lodgepole pine" lumber. The presence of up to ten per cent or more of large whitebark pine in commercial stands in the region is an ecological enigma. It appears that this species can compete favorably with lodgepole pine and spruce on the better sites, but is usually restricted to timberline scrub. Inability to regenerate where fire frequency is high may be responsible. An inherent ability to survive at timberline coupled with excellent growth capability should recommend this species for management on sites where regeneration is difficult.

Novel players fine-tune plant trade-offs

2015 ◽  
Vol 58 ◽  
pp. 83-100 ◽  
Author(s):  
Selena Gimenez-Ibanez ◽  
Marta Boter ◽  
Roberto Solano
Keyword(s):  
Ubiquitin Ligase ◽  
Feedback Loop ◽  
Molecular Level ◽  
26S Proteasome ◽  
Signalling Molecules ◽  
Transcriptional Reprogramming ◽  
Trade Offs ◽  
Jaz Proteins ◽  
Regulatory Feedback Loop ◽  
Fine Tune

Jasmonates (JAs) are essential signalling molecules that co-ordinate the plant response to biotic and abiotic challenges, as well as co-ordinating several developmental processes. Huge progress has been made over the last decade in understanding the components and mechanisms that govern JA perception and signalling. The bioactive form of the hormone, (+)-7-iso-jasmonyl-l-isoleucine (JA-Ile), is perceived by the COI1–JAZ co-receptor complex. JASMONATE ZIM DOMAIN (JAZ) proteins also act as direct repressors of transcriptional activators such as MYC2. In the emerging picture of JA-Ile perception and signalling, COI1 operates as an E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S proteasome, thereby derepressing transcription factors such as MYC2, which in turn activate JA-Ile-dependent transcriptional reprogramming. It is noteworthy that MYCs and different spliced variants of the JAZ proteins are involved in a negative regulatory feedback loop, which suggests a model that rapidly turns the transcriptional JA-Ile responses on and off and thereby avoids a detrimental overactivation of the pathway. This chapter highlights the most recent advances in our understanding of JA-Ile signalling, focusing on the latest repertoire of new targets of JAZ proteins to control different sets of JA-Ile-mediated responses, novel mechanisms of negative regulation of JA-Ile signalling, and hormonal cross-talk at the molecular level that ultimately determines plant adaptability and survival.

Dual Goals for Speed and Accuracy on the Same Performance Task

2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt
Keyword(s):  
Memory Scanning ◽  
Performance Task ◽  
Performance Tasks ◽  
Trade Off ◽  
Test Experiment ◽  
Trade Offs ◽  
New Finding ◽  
Sternberg Paradigm ◽  
Speed Accuracy ◽  
Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

Traits and trade-offs are insufficient for evolutionary personality psychology.

2007 ◽  
Vol 62 (9) ◽  
pp. 1073-1074 ◽  
Author(s):  
Kennon M. Sheldon ◽  
Melanie S. Sheldon ◽  
Charles P. Nichols
Keyword(s):  
Personality Psychology ◽  
Trade Offs
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