1,720,965 research outputs found
Using 2021 Field Data to Model Change in Forest Inventory Attributes From a 2014 LiDAR Derived Inventory for the United Counties of Prescott and Russell, Ontario
Get PDFRemote sensing technologies have been widely adopted in the forest sector for producing forest resource inventories. Airborne Laser Scanning LiDAR data that characterize the horizontal and vertical structure of forest stands have been shown to accurately estimate forest inventory attributes in multiple studies. This study assessed the feasibility of updating a private forest lands inventory derived from 2014 ALS LiDAR data using ground plot data collected in 2021 to model change in basal area, volume, and average stand height. Using these field data, basal area, merchantable volume, and height increments were determined for a subset (n=32) of stands included in the original 2014 inventory. Both 2nd order polynomial regression and random forest ensemble learning methods were used to model annual growth increments for these attributes and results were subsequently compared. For the original inventory, a suite of LiDAR summary statistics was derived from the distribution of LiDAR returns for each 20 m x 20 m cell in a raster map of the United Counties of Prescott Russell (Woods, 2020). We used these same underlying data to develop the random forest models for our study. For our regression models, we chose instead to use the inventory attributes derived from these data for each 20 x 20 m raster cell as independent variables due to the collinearity of a multitude of LiDAR summary statistics from which the attribute estimates were modeled The variance explained using random forest regression to model basal area (R2=0.64) and volume (R2=0.41) increments was greater than that explained using linear regression (R2=0.52 & R2=0.23, respectively). Conversely, for height increment, goodness of fit was substantially greater using linear regression (R2=0.76) than it was using the random forest approach (R2=0.20). However, root mean square error was consistently lower using random forest as opposed to linear regression to model all three attribute increments, suggesting random forest produced more accurate results overall. Although random forest produced marginally more accurate estimates, these results could not be extrapolated to the landscape with confidence due to limitations associated with that approach. Rather, the quadratic equations from the regression models for basal area, volume, and height increments were used to predict 2021 values for basal area (m2/ha), volume (m3/ha) and average height (m) across the landscape. We deemed the results of predictive modeling at the landscape scale to be reasonable in terms of ecological expectations despite recognized model weaknesses. Increasing sample size to capture a greater diversity of stand types and allow for some stand type or species-specific modeling would no doubt result in much better predictions. We conclude that it is indeed feasible to model change in LiDAR-derived inventory attributes over time using these methods. However, we caution against relying heavily on the approaches described here unless better predictive models can be developed from a comparatively larger and more representative sample of ground plots in future studies
Intact Forest Landscapes and their intersection with areas of high ecological value on forestry tenures in Ontario: a case study approach to evaluating trade-offs between enhanced local protection and loss of productive forest area
Get PDFCarbon Offset Projects for Land Trusts and Landowners in Southern Ontario: Challenges and Opportunities
No full textSouthern Ontario’s natural ecosystems have been subject to immense pressure from a historical prioritization of agriculture and population growth which has led to development pressure and urban sprawl. The combination of agriculture and development in this region led to an annual deforestation rate of 631 ha between 2006-2011. Ontario’s population is expected to increase by one-third by 2048, which will inevitably come at the expense of natural landscapes of the region, especially factoring in climate change. Despite these challenges, land trusts and some environmentally conscious landowners are doing positive work to conserve and sustainably manage important ecosystems. The former are non-profit organizations that rely on financial and property donations; all of which work towards their goal of conserving and protecting nature in perpetuity. However, relying solely on donations to fund conservation activities is a challenge for many land trusts and many private landowners don’t see the value in protecting their woodlots as opposed to harvesting. An emerging strategy to reward and promote the conservation and sustainable management of forests is the development of income generating carbon offset projects. Governments, companies, and individuals can offset their emissions by investing in projects that sequester green house gases (GHGs), including afforestation, reforestation, and forest management that improves upon the status quo. The carbon offset market has evolved rapidly in recent years. Opportunities now exist for land trusts and landowners to use their land to participate in forest carbon offset projects and be financially rewarded for doing so. This review paper offers an information package on forest carbon offset projects that highlights the history of carbon offsets, details the process of conducting forest carbon offset projects, and describes the challenges and opportunities attached to engaging in such endeavours. The recent experience of Ontario’s Escarpment Biosphere Conservancy (EBC) is utilized herein to inform readers about conducting an “Improved Forest Management” carbon offset project. Finally, a landowner’s guide to carbon offsets is attached (Appendix I) in order to provide landowners with a succinct guide to undertaking carbon offset projects that may compliment current conservation, preservation and restoration initiatives on private lands in Southern Ontario
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mid-Rotation Thinning Strategies in Lodgepole Pine Under Varying Stand Density Conditions: A TASS Simulation Study
Get PDFStand density is a primary driver of structure, growth, and productivity in even-aged lodgepole pine (Pinus contorta var. latifolia) stands. This study evaluated responses across three mid-rotation lodgepole pine blocks using stand-level metrics and TASS growth modeling. Species-level analyses showed that lodgepole pine dominated all blocks, accounting for 74–95% of stand composition and exhibiting low variability across basal area, diameter, and stem density (CV ≤ 20%). In contrast, spruce, balsam fir, and deciduous species displayed high coefficients of variation (57–118%) which shows little contribution to stand structure or dynamics. Low Shannon diversity and evenness values further confirmed the monoculture nature of these stands. This supported the exclusion of minor species from growth modeling and the treatment of each block as a lodgepole pine monoculture in TASS simulations.
When modeling thinning scenarios, the responses differed greatly depending on initial stocking level. In the overstocked block, thinning reduced early density driven mortality, increased diameter growth, and improved total volume by capturing stems otherwise lost to self-thinning. In the moderately stocked block, thinning increased individual tree size but reduced total yield. This showed that thinning timing is more critical than thinning intensity. In the understocked block, thinning provided minimal structural benefit and resulted in substantial volume loss. Results suggested that thinning is counterproductive when stands are below the Zone of Imminent Mortality (ZIM).
Overall, results indicate that optimal management of lodgepole pine stands depends on maintaining mid-rotation stem densities near 900–1200 stems per hectare. This allows for the highest productivity by to minimizing mortality and maximize yield. Thinning is most beneficial in overstocked stands, due to competition induced mortality. Moderately stocked stands require delayed thinnings to fully take advantage of the treatment. While thinning is not recommended in understocked stands. This study emphasizes the importance of early density management and site-specific silvicultural prescriptions to optimize long-term stand productivity
A regeneration monitoring protocol for the restoration of coniferous plantations to hardwood forests in southern Ontario
Get PDFThis report describes the development and implementation of a monitoring protocol for assessing hardwood regeneration in thinned coniferous plantations. Restoration of coniferous plantations to native mixed hardwood forest through repeated thinnings, with the intention of creating conditions for natural regeneration of hardwood tree species, is a common practice in southern Ontario. However, formal monitoring of this process has typically not occurred. The Credit Valley Conservation Authority sponsored the development of this regeneration monitoring protocol to assist them with management of coniferous plantations on their properties. The protocol was developed primarily through literature review, and includes regeneration standards, a survey methodology, and a data analysis system. Three overlapping regeneration standards inform this plot-based monitoring protocol to capture different stages of the restoration process. The survey methodology was designed for ease of implementation and efficiency. This monitoring protocol was tested at a forest in the Credit River Watershed with several distinct coniferous plantation stands. Initial results suggest that the survey methodology is suitable for assessing stocking of hardwood regeneration for a range of tree sizes, and that, as expected, stocking was on average higher in stands that had been thinned more than once. Because survey results indicate restoration progress, they can be used to inform future management decisions such as to continue with additional thinning treatment(s) and/or consider supplementary tree planting. Further implementation of the protocol at different sites is recommended
A comparative assessment of the health condition of recently planted native and non-native soft fruit-bearing and non-soft fruit-bearing tree species in Brampton, Ontario.
Get PDFWith an increasing population and associated development pressures, the City of Brampton (COB) recognizes the need to establish, maintain, and protect urban street trees for the myriad of benefits that they provide. Soft fruit bearing tree species are increasingly being planted due to their unique ecological services that they provide as food sources for wildlife. This study compares the health condition of recently planted native soft fruit-bearing trees to other native and non-native tree species in order to evaluate their performance and better understand their maintenance needs. A 2019 street tree inventory database was used to select tree species and species groupings for these comparisons. The health condition of individual trees was assessed during the inventory and condition ratings were assigned to each tree based on a combination of visual cues. In order to focus on recently planted stock, only trees with a diameter at a breast height (DBH) of less than 10 cm, were included in the analyses. Tree species were grouped for analyses according to their fruiting body characteristics and origin: native soft fruit, native non-soft fruit, non-native soft fruit, and non-native non-soft fruit groups. Sample size was highly variable among species that met these criteria. Differences in the order of magnitude of individual tree species’ sample sizes were therefore used to further divide the groupings into subsets that included tree species with less than 100, between 100 to 1000, and greater than 1000 individual samples. The comparison of median health condition rankings among groups within each subset indicated that native fruit-bearing saplings were in significantly better condition than non-native soft fruit-bearing saplings in subsets with less than 100 samples per species and between 100 to 1000 samples per species, respectively. However, the reverse was true for the subset that included only tree species with greater than 1000 individuals. These conflicting results were attributed to the fact that each subset contained different species within each fruit type and origin-based group; species for which tolerance to urban tree stressors differed. Nevertheless, results of this study infer that many native soft fruit bearing tree species are more resilient to urban stressors than their non-native counterparts, which merits an increase in the proportion of new street tree plantings comprised of these species. For other native soft fruit bearing tree species that are planted in much greater numbers, results suggest that additional maintenance may be required. In combination, both of these recommended actions promise to maximize the ecological services to co-adapted native wildlife that native soft fruit-bearing tree species provide
Carbon Offset Projects for Land Trusts and Landowners in Southern Ontario: Challenges and Opportunities
Get PDFSouthern Ontario’s natural ecosystems have been subject to immense pressure from a historical prioritization of agriculture and population growth which has led to development pressure and urban sprawl. The combination of agriculture and development in this region led to an annual deforestation rate of 631 ha between 2006-2011. Ontario’s population is expected to increase by one-third by 2048, which will inevitably come at the expense of natural landscapes of the region, especially factoring in climate change. Despite these challenges, land trusts and some environmentally conscious landowners are doing positive work to conserve and sustainably manage important ecosystems. The former are non-profit organizations that rely on financial and property donations; all of which work towards their goal of conserving and protecting nature in perpetuity. However, relying solely on donations to fund conservation activities is a challenge for many land trusts and many private landowners don’t see the value in protecting their woodlots as opposed to harvesting. An emerging strategy to reward and promote the conservation and sustainable management of forests is the development of income generating carbon offset projects. Governments, companies, and individuals can offset their emissions by investing in projects that sequester green house gases (GHGs), including afforestation, reforestation, and forest management that improves upon the status quo. The carbon offset market has evolved rapidly in recent years. Opportunities now exist for land trusts and landowners to use their land to participate in forest carbon offset projects and be financially rewarded for doing so. This review paper offers an information package on forest carbon offset projects that highlights the history of carbon offsets, details the process of conducting forest carbon offset projects, and describes the challenges and opportunities attached to engaging in such endeavours. The recent experience of Ontario’s Escarpment Biosphere Conservancy (EBC) is utilized herein to inform readers about conducting an “Improved Forest Management” carbon offset project. Finally, a landowner’s guide to carbon offsets is attached (Appendix I) in order to provide landowners with a succinct guide to undertaking carbon offset projects that may compliment current conservation, preservation and restoration initiatives on private lands in Southern Ontario
A comparative assessment of the health condition of recently planted native and non-native soft fruit-bearing and non-soft fruit-bearing tree species in Brampton, Ontario.
No full textWith an increasing population and associated development pressures, the City of Brampton (COB) recognizes the need to establish, maintain, and protect urban street trees for the myriad of benefits that they provide. Soft fruit bearing tree species are increasingly being planted due to their unique ecological services that they provide as food sources for wildlife. This study compares the health condition of recently planted native soft fruit-bearing trees to other native and non-native tree species in order to evaluate their performance and better understand their maintenance needs. A 2019 street tree inventory database was used to select tree species and species groupings for these comparisons. The health condition of individual trees was assessed during the inventory and condition ratings were assigned to each tree based on a combination of visual cues. In order to focus on recently planted stock, only trees with a diameter at a breast height (DBH) of less than 10 cm, were included in the analyses. Tree species were grouped for analyses according to their fruiting body characteristics and origin: native soft fruit, native non-soft fruit, non-native soft fruit, and non-native non-soft fruit groups. Sample size was highly variable among species that met these criteria. Differences in the order of magnitude of individual tree species’ sample sizes were therefore used to further divide the groupings into subsets that included tree species with less than 100, between 100 to 1000, and greater than 1000 individual samples. The comparison of median health condition rankings among groups within each subset indicated that native fruit-bearing saplings were in significantly better condition than non-native soft fruit-bearing saplings in subsets with less than 100 samples per species and between 100 to 1000 samples per species, respectively. However, the reverse was true for the subset that included only tree species with greater than 1000 individuals. These conflicting results were attributed to the fact that each subset contained different species within each fruit type and origin-based group; species for which tolerance to urban tree stressors differed. Nevertheless, results of this study infer that many native soft fruit bearing tree species are more resilient to urban stressors than their non-native counterparts, which merits an increase in the proportion of new street tree plantings comprised of these species. For other native soft fruit bearing tree species that are planted in much greater numbers, results suggest that additional maintenance may be required. In combination, both of these recommended actions promise to maximize the ecological services to co-adapted native wildlife that native soft fruit-bearing tree species provide
- …
