Ontario Jack Pine Research Articles

Woody biomass removal in harvested boreal forest leads to a partial functional homogenization of soil mesofaunal communities relative to unharvested forest

Land-use intensification can lead to taxonomic and/or functional homogenization of biotic communities, with potential consequences for ecosystem functioning. In boreal forests, managers are increasingly considering intensifying woody biomass removal for bioenergy, but associated functional effects on soil fauna that use microhabitats associated with this biomass remain poorly understood. Two years after harvesting, we assessed the effects of an increasing intensity gradient of biomass removal in a northeastern Ontario jack pine (Pinus banksiana) stand on the functional structure of Collembola and Oribatida communities, two abundant soil taxa. The gradient ranged from (1) uncut forest to (2) stem-only harvesting to intense biomass removal through (3) whole-tree harvesting (stem, top and branches) with (4) stump removal and (5) additional removal of organic soil strata. Morphological and life-history response traits associated with hypothesized functions were measured to determine changes in the functional structure (species trait diversity and composition) of communities in response to the gradient and related environmental changes. We found that functional structure of communities of both taxa was overall significantly modified by biomass removal through a compositional shift in species traits in comparison to uncut forest. Functional homogenization was observed for Oribatida communities with a loss of species that were surface-dwelling, larger, predominantly sexually reproducing and mostly micro-detritivorous. In contrast, Collembola communities were less affected with only the most extreme treatment showing a more homogenized community than the uncut forest. These functional changes were mainly explained by fewer suitable microhabitats, characterized for example by a more stable microclimate as well as more abundant and diverse food resources, due to the disturbance of forest floor organic cover with harvesting. To improve sustainable management of boreal forests, long-term studies will be needed to assess if partial functional homogenization of soil mesofauna by intensive practices persists through time and may influence soil ecosystem function.

Effect of vegetation control, harvest intensity, and soil disturbance on 20-year jack pine stand development

Currently, there are uncertainties regarding the impacts and (or) efficacy of biomass harvesting and silvicultural practices on stand production on coarse-textured boreal soils. Replicated factorial field experiments examining effects of complete vegetation control (repeated glyphosate application) following operational stem-only harvest with disc trenching (SOT), operational whole-tree harvest with (WTT) and without (WT) disc trenching, and whole-tree harvest with complete forest floor removal by blading (WTB) and blading followed by compaction (WTBC) were installed on four sandy northern Ontario jack pine (Pinus banksiana Lamb.) sites. Over 20 years, WTB improved planted-tree survival but decreased longer term stand productivity in comparison with other harvest intensity – soil disturbance treatments. Vegetation control improved tree growth and stand productivity initially, but over time, benefits declined substantially. SOT and WTT had similar impacts on stand production. Disc trenching improved initial planted-tree growth (WTT vs. WT), particularly without vegetation control. Jack pine natural regeneration was greatest with SOT, accounting for 25% of stand biomass at year 20. Stand structure effects included increased size inequality of naturals with WTB and reduced size inequality and asymmetry of naturals with vegetation control. Overall, impacts of forest floor removal and natural regeneration on stand development have become increasingly important over time compared with those of vegetation control.

A test and application of the model ForNBM in a northeastern Ontario jack pine ( Pinus banksiana lamb.) stand

The model, ForNBM, was used to simulate biomass growth, soil temperature, hydrology, and nutrient cycling in a jack pine forest in northeastern Ontario. Simulated forest biomass growth, water, and nutrient fluxes were compared with up to 9 years of field measurements. The results show that r 2-values between predicted and measured monthly soil leaching of five main nutrient ions (NO 3 −-N, NH 4 +-N, Ca, Mg, and K) range from 0.65 to 0.98, with the best simulation for Ca and the worst for NO 3 −-N. Predicted biomass growth, biomass nutrient content, and cumulative nutrient leaching strongly agree with measurements (all r 2-values >0.9). For the given jack pine stand, the model predicts that N and K supply for jack pine uptake mainly came from soil organic matter mineralization (61 and 60%, respectively). Ca supply is mainly from soil mineral weathering (50%) and K supply from both soil mineral weathering and organic matter mineralization (30 and 30%, respectively). As such, clear-cutting of the jack pine forest may result in a minimal overall degradation of nutrient supply, especially for N and K, for future forest biomass growth.

Understory vegetation in northern Ontario jack pine and black spruce plantations: 20-year successional changes

The 20-year successional development of understory vegetation was investigated in jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) BSP) plantations in northern Ontario, in relation to stand species composition, species diversity, and the rate of change in stands of different post-disturbance ages. Detrended correspondence analysis (DCA) ordination of plantation stands using species composition data from 1978 and 1998 indicated variation among stands in directions and rates of change in species composition over time. Rank correlations of environmental variables with the DCA axes suggested a light–moisture gradient along the first axis, driven by soil texture and overstory species, and a gradient representing time since disturbance and stand development along the second axis. Although overall beta diversity among stands remained constant over time, some convergence was found among a smaller group of stands, and divergence was noted between spruce and pine stands. Species composition also became more highly correlated with environmental variables through time. From 1978 to 1998, species richness increased in young, dry pine stands; decreased in older, dry pine stands; and decreased in young spruce stands. The understory vegetation in stands on mesic sites was more diverse than that on dry, sandy sites at both times. The rate of change in understory species composition slowed with time after disturbance, indicating an increasing stability in micro en vi ron men tal conditions as the influence of harvesting disturbance became weaker with time.

A Mathematically Tractable Stem Profile Model for Jack Pine in Ontario

Abstract A new model was derived to describe the inside bark cross-sectional area of tree stems. It is a rational function. The inputs required by the model are outside bark tree diameter at breast height (DBH) and total tree height (H). Knowledge of a species-specific bark thickness at 1.3 m expressed in terms of input variables is also needed. Defining the model involves estimating two regression coefficients using either nonlinear or linear regression (after linearization of the model). The formula is analytically integrable and thus provides analytical inside bark volume estimates for any stem section defined by height limits. The model is analytically solvable for a stem height location at any given inside bark diameter, so that stem sections can be defined by the required inside bark diameter limits. The new model can be calibrated using either section diameter or section volume data. It is suggested that involving the ratio H/DBH in the model accounts for the influence of stand density on stem profile. The formula was calibrated for jack pine (Pinus banksiana Lamb.) in Ontario. Wider applicability of the model is supported by results obtained for sugar maple (Acer saccharum Marsh.) in Ontario and Scots pine (Pinus silvestris L.) in Finland. Comparing volume estimates from the new model with those generated by Honer's formula confirms the advantages of the new model. North. J. Appl. For. 16(3):138-143.

Effect of clear-cutting, prescribed burning and scarification on litter decomposition in an Eastern Ontario jack pine (Pinus banksiana) ecosystem

Mass losses of litter bags containing leaf litter of Pinus banksiana Lamb., Quercus rubra L., Pteridium aquilium (L.) Kuhn, and Populus tremuloides Mchx. were compared in a jack pine ecosystem after clear-cutting, clear-cutting plus prescribed burning, and clear-cutting plus disk trenching scarification. Controls consisted of litterbags left in undisturbed plots. Mass losses were significantly affected by treatment types and litter types. The greatest differences among treatments were observed after 1 year of field incubation whereas there were considerably fewer differences among treatments after 3 years of incubation in the field. Initial decomposition of P. tremuloides and Q. rubra litter was greatest in the control plots. Scarified plots showed the slowest decomposition rates. Mass losses were not significant among treatments and litter types after 3 years incubation except for P. aquilinum litter on clear-cut and scarified plots.

New application of a polynomial curve to plot volume estimation

This paper presents a new method of plot volume estimation using a limited sample of heights. It requires measurement of all diameters in the plot and a limited number of height measurements per plot within a plot-specific diameter class predefined by the method. It also requires a diameter-based description of tree form. The method utilizes a polynomial curve to relate heights and diameters, but does not provide information on the plot height structure in the form of a traditional height–diameter curve. The approach was examined using data from north-central Ontario jack pine (Pinusbanksiana Lamb.) stands. The developed method of stand volume estimation is precise and unbiased with respect to height measurements; it reduces laborious height measurements compared with traditional methods utilizing a height–diameter curve.

The Long-Run Timber Supply Function

Abstract The long-run equivalent annual timber supply functions resulting from two increasingly complicated versions of the Faustmann model were derived and examined. In both cases, the expression for the equivalent annual quantity of timber supplied was identical. A second main result was the mathematical proof that the slope of the long-run timber supply curve is positive along its entire length when establishment costs are fixed and variable. Some calculations were made using a well-established yield function for jack pine in Ontario, and these supported the theoretical conclusions. In contrast, the use of V*/t* as the equivalent annual output incorporates the implicit assumption that the discount rate is zero. For. Sci. 36(1):77-86.

Decomposition, litter fall, and forest floor nutrient dynamics in relation to fire in eastern Ontario jack pine ecosystems

Decomposition, litter fall, and nutrient and organic matter turnover rates were determined in five eastern Ontario jack pine (Pinusbanksiana Lamb.) stands having various burning histories, including wildfire. The stands included a 65-year-old age-class (stand No. 1), two stands within this age-class that were treated with nonlethal understorey fires in 1962 and 1963 (stand Nos. 2 and 3, respectively), a 21-year-old age-class (stand No. 4), and an 8-year-old age-class (stand No. 5) created by experimental burning plots within the 21-year-old age-class. Overstorey and understorey litter decomposition was assessed separately using the litterbag (1-mm mesh size) technique over a 2-year period. Overstorey litter weight loss did not vary among stands and understorey litter lost significantly more weight (P < 0.05) in the older age-classes (stands 1,2, and 3) compared with the younger stands (stands 4 and 5). Litterbag nutrient dynamics between overstorey and understorey were significantly different (P < 0.05) for P, K, and Cain all stands. Magnesium and N dynamics were the same in both litter types on all treatments, as was Fe, except in the 65-year-old stand where significantly more Fe was accumulated in understorey litter (P < 0.04) at the end of the litterbag exposure period. Three-year averages of annual litter fall ranged from 119 kg•ha−1•year−1 in the 8-year-old age-class to 4182 kg•ha−1•year−1 in the older stands. Nutrient inputs through litter fall reflect the developmental stage occupied by the younger stands along a continuum leading to equilibrium conditions of the 65-year-old age-class. Forest floor nutrient and organic matter residence times (or annual fractional turnover) were longest (least amount cycled) in the 8-year-old stand (57.6 years for organic matter), indicating harsh environmental controls over nutrient dynamics. Recovery for the 21-year-old age-class to turnover rates approaching equilibrium conditions (10-year residence time for organic matter) was rapid, demonstrating ecosystem stability in its interaction with fire. Detrimental effects on ecosystem processes can be expected if a stand-replacing fire recurs during early stages of jack pine ecosystem development.

Selected Parameters of Fire Behavior and Pinus banksiana Lamb. Regeneration in Eastern Ontario

Fire behavior variables were quantified in eastern Ontario jack pine (Pinus banksiana Lamb.) ecosystems and used to interpret observed fire impacts and effects. A series of seven fires, ranging in frontal fire intensity from 70 to 17 000 W/m, were documented. Forest floor moisture content prior to burning was negatively correlated with weight of forest floor consumed per unit area (r2 = 0.97) and per cent mineral soil bared (r2 = 0.95). Frontal fire intensity was positively correlated with per cent tree mortality (r2 = 0.98) and mean height of char (r2 = 0.76). Frontal fire intensities of 17 000 kW/m resulted in seedling numbers of 30 000 to over 50 000 ha−1 considered to be more than adequate for establishing the next generation of crop trees. Jack pine mean seedling height, 13 to 16 years after fire, was also positively correlated with frontal fire intensity (r2 = 0.82), ranging from 0.5 to 3.8 m on lowest and highest intensity burns, respectively. Similar relationships were found when seedling height was regressed against per cent tree mortality (r2 = 0.62) and forest floor consumption (r2 = 0.79).Results are discussed in terms of ecological requirements of the species, particularly during the regeneration phase, and it is concluded that quantification of fire behavior observations is mandatory if burning conditions are to be understood and/or duplicated by the land manager for the attainment of a given forest management objective.

Tree size, biomass, and volume growth of twelve 34-year-old Ontario jack pine provenances

Tree size and aboveground biomass in twelve 34-year-old Ontario jack pine (Pinusbanksiana Lamb.) provenances growing at Petawawa National Forestry Institute (Chalk River, Ontario) was negatively correlated with latitude of origin. The best provenance exceeded the local provenance in tree height and diameter by approximately 10%. The pattern of geographical variation was stable over time, making general and sound predictions of provenance growth based on juvenile performance feasible. Persistent differences among some geographically close provenances indicated the potential for genetic improvement by selecting the best populations within site regions. The results demonstrated have important implications for jack pine breeding and improvement strategies at the provenance level. The provenance averages of aboveground ovendry weight per tree ranged from 44 to 79 kg. The aboveground tree biomass was distributed as follows in seven analyzed provenances: stem wood, 78%; stem bark, 8%; branch wood, 8%; needles, 5%; cones, 1%. Variation in average stemwood mass among provenances was less than the variation in average stem volume because of a strong negative correlation on a single tree basis between stem volume and stem wood density. The mean annual volume and biomass accretion per hectare in the best provenances averaged 10 m3 and 4 t, respectively. Total stem volume production per hectare varied exponentially with tree height. Mean annual stem volume increment of the best provenances exceeded that of the slowest growing provenances by 22–40%.

Forest soil respiration in eastern Ontario jack pine ecosystems

Forest soil respiration insitu was used as a comparative measure of the metabolic activity of substrate in eastern Ontario jack pine (Pinusbanksiana Lamb.) ecosystems that had been exposed to various burning treatments, including wildfire. The five burning treatments consisted of a 1920 wildfire, experimental understorey burning (nonlethal to the overstorey) of this age-class in 1962 and 1963, a 1964 wildfire, and experimental burning of this age-class in 1977. Seasonal respiration trends were similar on all treatments. Carbon dioxide evolution increased in the spring (4000 mg•m−2•d−1) in response to ambient warming (5000 mg•m−2•d−1 in August) and decreased in late fall as seasonal temperatures declined (4000 mg•m−2•d−1 in November). Precipitation and autumnal litter fall apparently acted as secondary modifiers of this general trend by affecting substrate moisture content and nutrient quality, respectively. Highest metabolic activities were measured on the 1963 understorey burning treatment followed in decreasing order by the 1920 wildfire, the 1964 wildfire, the 1962 experimental understorey burn, and the 1977 burn of the 1964 age-class. Multiple comparisons of overall seasonal respiration means revealed lower rates (P < 0.01) on the latter two treatments compared with the 1963 treatment. Effects of understorey burning treatments on respiration activity appeared to depend on depth of burn and subsequent forest floor development. Stand-replacing fire, reoccurring during early stages of jack pine ecosystem development, significantly lowered metabolic activity of the site.

The effect of forest floor manipulation on nitrogen status and tree growth in an eastern Ontario jack pine ecosystem

Four forest floor manipulation treatments were applied to an eastern Ontario jack pine (Pinusbanksiana Lamb.) ecosystem. These included a one-time complete removal of the forest floor to mineral soil; annual removal of the total forest floor to mineral soil; one-time removal of the forest floor, ashing of the material, and broadcast spreading of the ash onto exposed mineral soil; and an untreated control. Eight years after treatment radial tree growth on the treated plots showed a 30% reduction compared with the untreated plot. Annual removal of the forest floor caused most severe nitrogen depletion in jack pine foliage, forest floor, and mineral soil. Effects of one-time removal and burning treatments were less severe, but significant. Any interference with the normal buildup of the forest floor during stand development should be avoided if site quality is to be maintained for tree growth.

Spatial aspects of sweetfern rust disease in northern Ontario jack pine – sweetfern stands

In the jack pine – sweetfern stands of northern Ontario, jack pine (Pinusbanksiana Lamb.), sweetfern (Comptoniaperegrina [L.] Coult.), and portions of jack pine populations infected by the host-alternating sweetfern rust (Cronartiumcomptoniae Arth.) were shown to have aggregated spatial distributions. Competition with sweetfern and mortality caused by the disease affected the distribution of both jack pine and cankered jack pine. Proximity to sweetfern was the most important variable for rating the rust infection hazard. Hazard was greatest in patches of sweetfern and appeared to diminish beyond a distance of 12 m. Cankers were unusual at distances greater than 30 m. In young stands, cankered pine were concentrated in and near patches of sweetfern. In older stands the spatial character of cankered pines was a function of the percentage that survived the seedling stage, the distribution of the jack pine and sweetfern populations, and the amount of competition experienced by the cankered population.

Discontinuity in Growth Potential of Jack Pine in Ontario: A 20-Year Provenance Assessment

The province of Ontario is divided into three major jack pine populations as a result of grouping 12 seed sources on the basis of growth characteristics, 20 years from sowing. Migration following glaciation is postulated as a cause of population differentiation.Growth of trees from the 12 stands was positively but weakly correlated with growing degree days. However some northern sources flourished in southern plantations. Consistent growth differences were found between some geographically close sources, justifying further, more intensive sampling to identify the most productive sources of seed for each of the major areas of jack pine silvicultural activity in the province.

Heart Rot of Jack Pine in Ontario. IV. Heartwood-inhabiting Fungi, Their Entry and Interactions within Living Trees

The five most common stem-inhabiting fungi of jack pine (Pinusbanksiana Lamb.) in Ontario were inoculated into the stems of living trees that were roughly 40 years old. Their natural occurrence in branch stubs and at various heights in the stems of these trees was also studied. From these results, and from those that were obtained from older trees in earlier studies, conclusions which concern the occurrence, importance, and apparent avenues of entry of these fungi are presented. Some of the trees were inoculated with one of the Ascomycetes, which was followed 1 year later by one of the Basidiomycetes. The interactions of the fungi in vivo did not always correspond with those observed in vitro; however, they do explain many of the observed relationships between the occurrence of these fungi in living jack pine and other factors. Fomespini (Brot. ex Fr.) Karst., the Basidiomycete that is responsible for most of the trunk rot of jack pine in Ontario, was not affected in living tree stems by the presence of the Ascomycetes that frequently colonize this tissue. On the other hand, Peniophorapseudo-pini Weres. and Gibson, the Basidiomycete that is responsible for about one quarter of the red trunk stain in this species, was almost completely inhibited in living trees by the presence of Ascocorynesarcoides (Jacq. ex Gray) Groves and Wilson, which would explain many of the unusual patterns of occurrence of P. pseudo-pini in living jack pine.

HEART ROT OF JACK PINE IN ONTARIO. III. DECAY RELATIONSHIPS AND THEIR EFFECTS ON MANAGEMENT

A total of 4,287 jack pine (Pinus banksiana Lamb.) trees were sampled throughout most of the range of this species in Ontario. Tree age was the factor associated with the greatest variation in the extent of defects of fungal origin (decay) within the merchantable bole. The amount of decay increased with host age, accelerating markedly after 90 to 100 years. A close relationship also was found between the extent of defective jack pine heartwood and three geographical regions of the Province. Roughly twice as much decay, on a volume percentage basis, was encountered in western Ontario as in eastern Ontario. A tendency for more decay to occur in relatively slow growing jack pine was observed; however, this was not statistically significant. Site, based on soil moisture regime, was related to the incidence of decay in the sample trees. There is evidence from this and other investigations that the growth rate of jack pine is highest on moderately dry to moderately fresh sites with soil moisture regimes 2 or 3. Most jack pine in Ontario occurs on very dry or dry soil moisture regimes 0 or 1. The extent of decay was significantly less on regimes 2 and 3 which represent the optimum sites for jack pine quality and growth in Ontario.

Observations on the Life History, Distribution, and Abundance of Two Species of Cecidomyia (Diptera, Cecidomyiidae) on Jack Pine in Manitoba and Saskatchewan

The occurrence of midges on jack pine, Pinus banksiana Lamb., in Manitoba has been reported by Lejeune (4), Barker and Wong (1), and Prentice and Hildahl (5, 6). The Forest Insect Survey also reported a species of Retinodiplosis on jack pine in Ontario, and Barnes (2) suggested that this may have been R. resinicola (Osten Sacken). This name was also provisionally assigned to a species found near Stead, Manitoba, in 1956 (7). Vockeroth (8) now shows that Retinodiplosis Kieffer is a synonym of Cecidomyia Meigen, which is represented by at least two species on jack pine in Manitoba and Saskatchewan. These are C. reeksi and C. banksianae. The former is the more common and undoubtedly was the species most frequently represented in the early reports of pine midges in Manitoba.

Notes on Leconte's Sawfly

Leconte's sawfly or the red-headed pine sawfly (Neodiprion lecontei Fitch) is a common insect attacking pines in Ontario. Plantations red pine are almost invariably attacked from the time the trees have reached two to four feet in height. Periodically epidemic populations cause significant damage. The life history and habits of the species have heen described by Middleton (2) who states that this insect attacks practically all species of pine as bell as larch. Schaffner (3) also indicates that the larvae feed on a wide variety of pine and occasionally on other conifers. Red pine (Pinus resinosa Ait.) is undoubtedly the usual host, although in Ontario jack pine (Pinus banksiana Lamb.) is sometimes attacked. In 1946 evidence was secured to show that jack pine needles may be selected for oviposition even in an area where red pine foliage is plentiful. (Figure 1).

Regional Growth and Yield of Spruce and Jack Pine in Ontario

Regional Growth and Yield of Spruce and Jack Pine in Ontario