Lodgepole Pine Plantations Research Articles

Individual-tree growth models for lodgepole pine (Pinus contorta) in Iceland

Lodgepole pine (Pinus contorta subsp. contorta) is one of the most important tree species planted in Iceland. The current plantation area is 7100 ha, the first plantations being 80 years old. This study presents models for simulating the development of Icelandic lodgepole pine plantations on an individual-tree basis. The model set consists of a site index model, tree height model, and diameter increment model. Data were collected in 35 permanent sample plots with measurement intervals ranging from 3 to 14 years. The total number of diameter increment observations was 3664. Regression analysis was used in site index and height modelling, and both regression analysis and optimization were tested in diameter increment modelling. An optimization-based model was evaluated to be the most suitable for growth simulations. The use of the developed model set was demonstrated in management optimizations, where the rotation length and cutting schedule were optimized for two young sample plots, one representing poor sites and the other good sites. The optimizations showed that planting is not profitable on poor sites if the discount rate is 4% or higher. The mean annual stem wood harvest was 2.7–4.1 m3ha-1a-1 on the poor site and 8.3–11.7 m3ha-1a-1 on the good site.

Flow-on effects of an introduced tree species: Lodgepole pine plantation affects function and performance of boreal ants

Increased demand on forests to produce renewable biomass have accelerated the use of non-native tree species in forestry worldwide, often with negative effects on native biodiversity. In Sweden, the North American lodgepole pine (Pinus contorta Douglas ex. Loudon var. latifolia) was introduced already in the 1970’s. Even though the species now covers large areas, effects on native flora and fauna have not been thoroughly evaluated. In this study, we used a large-scale field experiment with 30 paired P. contorta and P. sylvestris stands in central and northern Sweden to study the effects of P. contorta plantation on the abundance and activity of red wood ants of the Formica rufa-group, density and species richness of other ant species, as well as possible effects on the abundance of the specialized ant predator Pella humeralis. We collected epigaeic insects with pit fall traps, surveyed wood ant mound density and volume, and monitored ant activity on trees in all stands. Our analyses revealed a trend with higher mound density in P. sylvestris compared with P. contorta stands, although wood ant worker catch did not differ between the pine species. However, red wood ant activity was significantly higher in P. sylvestris stands, suggesting that P. contorta is not a preferred tree species for the tending of aphids for honeydew. Total ant species richness as well as the catch of Camponotus herculeanus and Myrmica ruginodis were higher in P. sylvestris stands, suggesting that they constitute a more favorable habitat for ants. Ant species richness was negatively influenced by wood ants in P. sylvestris stands only. A similar pattern was shown for C. herculeanus. Myrmica ruginodis was more abundant in P. sylvestris stands only if no thinning had been applied. Wood ant catch was positively correlated with catch of the specialized predatory rove beetle Pella humeralis showing that there is a strong interaction between the predatory beetle and wood ants.Our results suggest that P. contorta plantations impact both red wood ants and associated species and although competition from wood ants is more pronounced in P. sylvestris stands they still constitute a more favorable habitat for most ant species. Thus, large scale plantation of the non-native but closely related P. contorta may negatively impact epigaeic assemblages, a pattern that is not compensated by released competition by dominant red wood ants.

Flow-On Effects of an Introduced Tree Species: Lodgepole Pine Plantation Affects Function and Performance of Boreal Ants

Flow-On Effects of an Introduced Tree Species: Lodgepole Pine Plantation Affects Function and Performance of Boreal Ants

Lodgepole pine of Yukon origin in the European North of Russia

The article is devoted to the study of Lodgepole pine plantations of northern Canadian (Yukon) origin, created in 1988 in the Arkhangelsk region on three sites with different growing conditions using different methods of the soil preparation for planting. The main research objective was studying the growth, sustainability and productivity of Lodgepole pine of Yukon origin in the conditions of introduction. The objects of research were three experimental plots of Lodgepole pine, created in 1988 in the Arkhangelsk region with two-year-old seedlings from seeds of Yukon origin. The results of Lodgepole pine growth in height, diameter and trunk volume indicate that this pine responds well to improved soil cultivation conditions and, undoubtedly, to pre-plant soil preparation. Lodgepole pine is characterized by good growth and straightness in the myrtillosum forest type and special microclimatic conditions on the Solovetsky Islands. Resulting from the study of growth and development of Lodgepole pine of Yukon origin, it was concluded that the creation of fast-growing forest plantations of this species is recommended in productive forest types of the hylocomiosa group (oxalidosum and fresh myrtillosum).

Estimating the growth of 20-to 26-year-old lodgepole pine plantations in the Leningrad region of Russia

Abstract The aim of our study was to compare the growth rates of lodgepole pine (Pinus contorta Dougl.) with those of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L.) in plantations. The experimental plots were established in 1988, 1989 and 1994 in the southern part of the Leningrad region. In 2014, the condition of the plants on those plots was examined and their linear parameters were measured. The comparison of Scots pine with lodgepole pine of the same age growing in similar soil conditions has shown that Scots pine has only an insignificant advantage over lodgepole pine in the growth rate. In the mixes of Norway spruce and lodgepole pine, Norway spruce considerably suppresses the growth of lodgepole pine. Lodgepole pine has successfully adapted to the climatic conditions of the Leningrad region of Russia, which is easy to see from the well-preserved plantations and their annual bearing. No significant damage because of either diseases or insect pests has been revealed. It is for the first time that the volume yield of lodgepole pine was determined in 20-to 26-year-old experimental plantations in the Leningrad region of Russia.

Состояние экспериментальных культур сосны скрученной в Республике Коми

Изложены результаты исследования четырех участков экспериментальных культур сосныскрученной в Республике Коми. В эксперименте представлено шесть происхождений сосны скрученной, выращенных из семян, заготовленных на лесосеменных плантациях Швеции, которые заложены по географическому принципу семенными потомствами плюсовых деревьев, отобранных в Канаде. Вкачестве контроля использовали семена сосны обыкновенной местного происхождения. Сосна скрученная превосходила сосну обыкновенную по объему ствола, однако доля стволов с дефектами у нее была выше. Установлена взаимосвязь показателей роста и качества ствола сосны скрученной с географической широтой происхождения материнских плюсовых деревьев в Канаде.

Lodgepole pine and trembling aspen competition: Neighbourhood studies within 22 to 39 year-old pine plantations of northern British Columbia

Six lodgepole pine plantations located within the Sub Boreal Spruce (SBS) biogeoclimatic zone of the northern interior of British Columbia were chosen to study the impacts of neighbourhood aspen competition on the growth of planted lodgepole pine (22–39 years old). At each site, 30 pine trees (CP) were selected as plot centres across the observed range of aspen competition. Information on the six nearest neighbours (NN) and a variety of competition indices were evaluated using linear and nonlinear models. Competition indices based on diameter or height relative to size were found as the best overall predictors of CP growth. Proximity of NN to the CP was found to be inconsistent as a predictor of growth. Individual pine and aspen NN modelling suggested aspen competition had the greatest influence on CP growth restriction. The results do not support aspen thresholds for optimizing the growth of free growing pine plantations. It is recommended that performance-based standards be developed that account for aspen competition intensity and provide guidance for the management of pine stand productivity.

Collar insertion depth effects on soil respiration in afforested peatlands

Using collars for measuring soil respiration and its component fluxes in closed chamber systems relies on two main assumptions. Firstly, it is assumed that shallow collars prevent lateral soil gas leakage beneath the chamber’s walls and the underestimation of soil CO2 fluxes, and secondly, the insertion of deeper collars excises all living roots and the autotrophic flux is eliminated. It was hypothesised that previous findings on collar insertion impacts on autotrophic and total soil respiration also apply to afforested peatlands. In these ecosystems, a large fraction of fine roots grow close to the soil surface. Therefore, the use of shallow collars may sever some fine roots and hyphae of mycorrhizal fungi, and therefore, it may lead to underestimation of total soil respiration. It was also hypothesised that this underestimation may be greater than a possible CO2 leakage from lateral diffusion of soil gas as a result of not using collars. In this study, we measured soil CO2 efflux in a Sitka spruce and a lodgepole pine plantation on blanket peat in southern Ireland. A surface collar (not inserted into the ground) and six insertion depths (5, 10, 15, 25, 35 and 45 cm) were established to assess the effect of the collar insertion depth on autotrophic and total soil respiration. The insertion depth of 5 cm reduced total soil respiration by 47 and 32% in the spruce and pine stands, respectively. Using nonlinear equations, it was estimated that a frequently used shallow insertion of 1.5 cm would have reduced this efflux by 35 and 20% in each stand, respectively. Moreover, it was demonstrated that this reduction was greater than a possible lateral soil gas leakage. These results suggest that the insertion of shallow collars should be avoided and surface collars permanently anchored in the soil should be used instead.

Cattle utilization of coniferous cut blocks under open range grazing and associated impact on tree seedlings

Open range grazing by cattle is common on heterogeneous montane landscapes in western Canada. These areas are often jointly managed for forestry, leading to concerns over forest re-establishment following clear cut harvest and cattle impacts on tree regeneration. A network of 154 field plots were used to examine cattle utilization across five coniferous cut blocks within three large pastures of SW Alberta over a 2 year period. Specific objectives were to: (1) quantify cattle presence across cut blocks under free-choice conditions; (2) identify the environmental factors responsible for observed patterns of cattle presence, including topography, distance to water, forage characteristics and slash properties; and (3) document cattle impact on conifer seedlings. Averaged over 2 years, evidence of cattle was found in 46 % of plots, primarily as herbage removal. Cattle presence across logged areas was associated with plots at lower elevations and closer to water, and to a lesser extent, those areas with greater forage biomass but lower quality. Forest surveys done 3 years after harvest indicated most tree regeneration consisted of planted lodgepole pine (Pinus contorta Loudon) and naturally regenerating Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). While regeneration among plots remained below the provincial requirement of 80 % stocking, ranging from 68 to 77 % among cut blocks, this deficit was not attributed to cattle impact, as only two tree seedlings surveyed had evidence of livestock-induced damage. Finally, cattle visitation to plots was lower with taller slash in select pastures, suggesting slash may deter cattle use of some cut blocks. Overall, the results of this study support the notion that forest management and cattle grazing are compatible uses on Montane landscapes managed for multiple purposes.

ЭКСПЕРИМЕНТАЛЬНЫЕ КУЛЬТУРЫ СОСНЫ СКРУЧЕННОЙ В СЫКТЫВКАРСКОМ ЛЕСНИЧЕСТВЕ РЕСПУБЛИКИ КОМИ

ЭКСПЕРИМЕНТАЛЬНЫЕ КУЛЬТУРЫ СОСНЫ СКРУЧЕННОЙ В СЫКТЫВКАРСКОМ ЛЕСНИЧЕСТВЕ РЕСПУБЛИКИ КОМИ

Warm summer nights and the growth decline of shore pine in Southeast Alaska

Shore pine, which is a subspecies of lodgepole pine, was a widespread and dominant tree species in Southeast Alaska during the early Holocene. At present, the distribution of shore pine in Alaska is restricted to coastal bogs and fens, likely by competition with Sitka spruce and Western hemlock. Monitoring of permanent plots as part of the United States Forest Service Forest Inventory and Analysis program identified a recent loss of shore pine biomass in Southeast Alaska. The apparent loss of shore pine is concerning, because its presence adds a vertical dimension to coastal wetlands, which are the richest plant communities of the coastal temperate rainforest in Alaska. In this study, we examined the shore pine tree-ring record from a newly established plot network throughout Southeast Alaska and explored climate-growth relationships. We found a steep decline in shore pine growth from the early 1960s to the present. Random Forest regression revealed a strong correlation between the decline in shore pine growth and the rise in growing season diurnal minimum air temperature. Warm summer nights, cool daytime temperatures and a reduced diurnal temperature range are associated with greater cloud cover in Southeast Alaska. This suite of conditions could lead to unfavorable tree carbon budgets (reduced daytime photosynthesis and greater nighttime respiration) and/or favor infection by foliar pathogens, such as Dothistroma needle blight, which has recently caused widespread tree mortality on lodgepole pine plantations in British Columbia. Further field study that includes experimental manipulation (e.g., fungicide application) will be necessary to identify the proximal cause(s) of the growth decline. In the meantime, we anticipate continuation of the shore pine growth decline in Southeast Alaska.

Lodgepole pine and trembling aspen mixedwoods: Growth and yield within 22 to 39 year old pine plantations of northern interior British Columbia

Six lodgepole pine plantations located in the Sub Boreal Spruce (SBS) biogeoclimatic zone of northern interior British Columbia were chosen to study the impacts of aspen competition on the growth and yield of lodgepole pine. The six sites from four different zonal variants (dw2, dw3, dk1 and mc2) ranged in age from 22 to 39 years. Site preparation treatments occurred on all sites: drag scarification, disking, or a broadcast burn post clear-cut logging. Four of the sites received at least one operational brushing treatment for aspen (chemical or manual). At each site, 30 pine trees (CP) were selected as plot centres to represent the observed range of aspen competition. A series of nested plots up to 7.98 m radius was used to evaluate effects of % pine composition on stand density and stand volume using linear and non-linear models. At five of the six sites total volume was unchanged across the range of pine composition. The growth interaction between aspen and pine was found to be a linear relationship of competitive reduction where pine volume, basal area and merchantable volume was highly sensitive to any increase in aspen density or composition.

Evidence against planting lodgepole pine monocultures in the cedar-hemlock forests of southeastern British Columbia

Single-species planting of lodgepole pine (Pinus contorta var. latifolia) following clear-cut logging or wildfire has been common throughout interior British Columbia, Canada, but health problems with the species have been documented as it grows beyond the juvenile stage. We examined damage and stocking in twenty-seven 15to 30-yearold lodgepole pine plantations that were previously declared free growing in the highly productive cedar–hemlock forests in southeastern British Columbia, where lodgepole pine is absent from many primary forests. In order to be free growing, stands must meet minimum tree density, height, damage and brush competition criteria as legislated by the Provincial government. Overall, 44 per cent of lodgepole pine trees had unacceptable damage (causing them to be rejected as crop trees), and as a direct result, one-third of the plantations were no longer defined as free growing because there were insufficient crop trees remaining. Natural regeneration of other tree species partially compensated for the unhealthy pine. Logistic regression and odds ratio analysis associated increasing risk of damage from western gall rust with increasing soil moisture, more northerly aspects and mechanical site preparation, and decreasing risk with pre-commercial thinning treatment. Risk of damage from snow and ice was associated with increasing mean annual precipitation, decreasing longitude and broadcast burning. Risk of bear damage was associated with increasing soil moisture, pre-commercial thinning treatment and broadcast burning. Based on our results, we recommend that single-species planting of lodgepole pine be curtailed in the Interior Cedar–Hemlock zone in southeastern British Columbia.

Spore Dispersal byDothistroma septosporumin Northwest British Columbia

We studied spore dispersal by Dothistroma septosporum, causal agent of a serious outbreak of red band needle blight in lodgepole pine plantations in northwest British Columbia. Spore abundance was assessed at different distances and heights from inoculum sources and microclimatic factors were recorded during two consecutive years. Conidia were observed on spore traps from June to September during periods of rainfall. It was rare to detect spores more than 2 m away from inoculum sources. The timing and number of conidia dispersed were strongly tied to the climatic variables, particularly rainfall and leaf wetness. Should the trend toward increased spring and summer precipitation in the study area continue, the results suggest that disease spread and intensification will also increase. Increasing the planting distances between lodgepole pine trees through mixed species plantations and overall reduction in use of lodgepole pine for regeneration in wet areas are the best strategies to reduce the spread of the disease and enhance future productivity of plantations in the study area.

Sheep vegetation management for controlling competing vegetation in young conifer plantations in the central interior of British Columbia, Canada

In British Columbia, sheep vegetation management (SVM) is a relatively new technique; thus, limited data are available for examining its benefits on conifer growth. We collected field data from young mixed-conifer plantations of lodgepole pine (Pinus contorta) and hybrid spruce (Picea glauca × P. engelmannii) in blocks which had been grazed in 2005 and 2006 as well as from ungrazed blocks. Our main objective was to determine if sheep grazing had a significant effect on the growth of hybrid spruce. We measured stem diameter at 15 cm height above the root collar (D15) and cumulative internodal length (IL). Cumulative IL was calculated from the node corresponding to the year 2002–2010 (positions 2–10). The height to diameter ratio (height to the base of the leader (position 10)/D15; HDR) was calculated to determine if seedlings prioritized growth in terms of height or diameter. There was no significant grazing treatment effect on D15 and HDR when compared to the control treatment; however IL was significantly affected after the second grazing treatment in 2006 (position 6) and became increasingly important with time (positions 7–10). Based on our results, we suggest that SVM could be an effective method for controlling competing vegetation and thus, increase annual tree growth for areas with similar site characteristics as those found within the plantations sampled.

Regional outbreak dynamics of Dothistroma needle blight linked to weather patterns in British Columbia, Canada

Dothistroma needle blight (DNB) has caused extensive mortality in plantations of lodgepole pine in northwestern British Columbia, Canada, and even mature pine trees in natural forests are succumbing. We examined a number of explanatory models to determine which temperature or precipitation variable is most important in explaining DNB outbreak occurrence. We compared a multicentury tree-ring outbreak reconstruction with mean monthly temperature and total monthly precipitation during the individual and seasonal spring (April, May, June) and summer (July, August, September) months. A trend towards increased August minimum temperatures appears to be an important climate factor contributing to the spread of the disease. Graphical comparisons of total April precipitation reveal that periods of above-average precipitation coincided with periods of outbreak increase. Decreases in August minimum temperature also correspond to decreases in outbreak severity. Even more pronounced was a spike in spring precipitation and its association with the current epidemic. The correspondence of past outbreaks with periods of wet and warm conditions suggests that regional climate trends drive DNB behavior. The extent and severity of the current disease epidemic raises the possibility that the key factors that drive outbreaks have become more frequent, enabling the emergence of DNB as a serious disease.

Testing indicators of biodiversity for plantation forests

In many parts of the world, plantations make up a considerable proportion of the total forest area. In such regions, the identification of high biodiversity value stands and of management practices to enhance biodiversity is essential if the goals of Sustainable Forest Management are to be achieved. Since complete biodiversity assessments are rarely possible, efforts have been increasingly focussed on the use of indicators. Of particular interest are indicators applicable to individual stands that require no specialist taxonomic or technical knowledge to assess. Candidate biodiversity indicators had been identified in a previous study using data from Irish Sitka spruce (Picea sitchensis) and ash (Fraxinus excelsior) plantations but had yet to be tested on independent data. In the present study, the provisional indicators for vascular plant, bryophyte, spider and bird diversity were tested on data from Irish Scots pine (Pinus sylvestris), oak (Quercus petraea/Quercus robur), Sitka spruce and lodgepole pine (Pinus contorta) plantations. Conifer canopy cover was confirmed as an important biodiversity indicator, due to its influence on below-canopy microclimatic and structural conditions. Bryophyte species richness was higher in relatively high canopy cover plantations on poorly drained soils, while bird species richness was higher in more open plantations with high shrub cover. Coarse woody debris was an important substrate for forest-associated bryophytes, with higher species richness at higher volumes of deadwood. Both proximity to old woodland and stand age were confirmed as positive indicators for forest-associated vascular plants. This is related to dispersal limitation in these species, with nearby woodlands acting as important seed sources and colonisation increasing with time. Stand age was also confirmed as a positive indicator for forest-associated spiders and is related to the development of suitable habitat as the plantation matures. All of the confirmed indicators can be assessed without need for specialist knowledge, are ecologically meaningful and applicable to a range of forests managed under a clearfelling system. They can be used to assess the potential value of stands for the taxonomic groups to which they apply, as well as giving insights into management practices to enhance diversity in these groups.

Effect of spacing on 23-year-old lodgepole pine (Pinus contorta Dougl. var. latifolia) in southern Sweden

The objective of this study was to compare volume growth and external timber quality properties of lodgepole pine (Pinus contorta Dougl. var. latifolia) stands planted in different spacings (1.41×1.41, 2.00×2.00, 2.83×2.83, 4.00×4.00) in southern Sweden. In northern Sweden lodgepole pine has been grown for a long time and shows superior volume production compared to Scots pine (Pinus Sylvestris L.). The Swedish Forestry Act restricts establishment of lodgepole pine plantations in southern Sweden. However, it is important to increase the knowledge about lodgepole pine and its potential use also in this part of the country. Two experiments in southern Sweden were studied. Each trial was designed as a random block experiment with two blocks. Both investigated stands had an age of 23 years at the time of assessment. The mean diameter and the volume production differed significantly between the spacings. The highest volume production was found in the narrowest spacing, 313% compared to the widest spacing. Significant differences between spacings were also found concerning external quality traits. The frequency of dominant and co-dominant trees without defects was 24% in the most open spacing compared to 46% in the narrowest one. Under current circumstances approximately 2500 seedlings/ha in the initial stand seems to be a reasonable compromise between growth, diameter development and timber quality.

Twenty year site preparation effects on sub-boreal lodgepole pine performance

We examined the effects of various mechanical site preparation methods and windrow burning on container-grown planted lodgepole pine (Pinus contorta var. latifolia) survival and growth for 20 years after treatment at a sub-boreal site in north-central British Columbia, Canada. Survival was uniformly high (≥80%) regardless of treatment, indicating that site preparation was not necessary to establish pine on this site. Significant treatment effects on height, diameter, and stem volume were present at all assessment dates, but only the windrow burning treatment was associated with growth gains over the untreated control after two decades. Pine planted at the disk trench hinge were significantly larger than control pine only until year five. Of the mechanical treatments, only coarse mixing (by bedding plow) continued to have a significant effect on pine growth for as many as 9 years after treatment. Despite the disappearance of significant differences between mechanical treatments and the untreated control by year 20, the magnitude of stand volume increases suggests the potential for mechanical site preparation to have a beneficial effect on future timber supply. Repeated measures analysis confirmed that trends in early diameter growth differed between the untreated control and the windrow burning or coarse mixing treatments. These data are also potentially valuable for verifying growth and yield or carbon budgeting modelling tools.

Effects of climate on growth of lodgepole pine and white spruce following site preparation and its implications in a changing climate

Site preparation and vegetation control can be used to mitigate climate change effects on early plantation growth in boreal forests. In this study, we explored growth of lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) and white spruce ( Picea glauca (Moench) Voss) in relation to climate and site preparation using 20 years of data collected from studies in British Columbia. Results indicate that up to 45% of the variation in spruce growth and up to 37% of the variation in pine growth over this 20-year period can be explained by selected climatic variables. Monthly climate variables showed a stronger relationship to conifer growth than seasonal and annual variables. Climate variables related to the preceding year accounted for more than half of the variables in the final equations, indicating a lagged response in conifer growth. Future projections indicated that height growth of young lodgepole pine plantations in the sub-boreal zone could benefit (in the short term) from longer growing seasons by up to 12% on untreated stands. Untreated young white spruce plantations in the boreal zone may suffer height growth decreases of up to 10% due to increased drought stress. Vegetation control and mechanical site preparation treatments appear to mitigate effects of climate change to some extent.