Ontario boreal fire regimes in the context of lightning-caused ignition point spatial patterns

Lightning-caused forest fires are one of the major natural disturbances in Ontario managed boreal forests. Survival of these forests with fires for centuries shows that such disturbances are integral to the boreal ecosystem and its ecological functioning. Characterizing the fire regimes defined by fire ignition frequency, fire sizes and their spatial distribution patterns etc. thus can help to improve our understanding of the boreal forest dynamics and provide guidance for management practices attempting to maintain biodiversity and achieve sustainability. In this thesis the lightning-caused fire ignitions data for four ecoregions in Ontario managed boreal forests (3E, 3W, 3S and 4S) for 1960–2009 were analyzed using pattern analysis and density estimation to determine the spatial nature of fire ignitions. These fire ignition spatial patterns were further used (as weighted ignition scenario) to simulate forest fire regimes in the study area. Fire regimes were also simulated using spatially unweighted ignitions (unweighted ignition scenario). Non-spatial (total number of fires, total burn area, number of fires by size classes, annual burn fraction) and spatial (spatial burn probability) indicators of the simulated fire regimes under both ignition scenarios were compared to test the null hypothesis that modeled forest fire regime is not affected by the spatial patterns of input fire ignitions. All data analysis were performed for individual ecoregions. Spatial pattern of ignitions were analyzed using the nearest neighbour index and Ripley’s K-function. Ignition densities were estimated using the adaptive kernel density estimation method and the fire regimes were simulated using BFOLDS (Boreal Forests Landscape Dynamics Simulator). Results showed that lightning-caused fire ignitions are clustered in all ecoregions. Fire ignition density also varied spatially within ecoregions. Overall fire ignition density was highest in the northwestern ecoregion (4S) and lowest in the eastern ecoregion (3E), which corresponds to the combined gradient of effective humidity and temperature in Ontario. For each ecoregion, comparison of non-spatial simulated fire regime indicators showed statistically non-significant differences between unweighted and weighted ignitions. The spatial burn probability however captured clear spatial differences between unweighted and weighted ignitions. Spatial differences in spatial burn probability between both ignition scenarios were more prominent in ecoregions of high fire occurrence. Results of the weighted ignition scenario closely followed the spatial patterns of the estimated fire ignition density in the study area. Based on these results this thesis rejects the null hypothesis and emphasizes that ignition patterns must be considered in simulating fire regime in Ontario boreal forests

IOT Based Fault Detection and Protection of Power Transformer in the Smart Grid

This paper presents a novel Arduino-based fault detection and protection system for power transformers. Power transformers are an integral component of the power system infrastructure. Power transformers are present in such a significant number in the power architecture that any alteration in its operation effects the whole power system. The optimal operation of the transformer depends upon its operating condition; for this reason, its monitoring and protection are very important. Currently, power transformers employ differential relays to ensure optimal operation, but differential relays are unable to ascertain conditions such as overloading and intra turn faults. In this paper, Arduino was used to monitor transformer operation instead of differential relays and generate tripping or alert signals based on sensed values. Arduino autonomously sensed the current, voltage, and temperature values of the power transformer round the clock and handled any fault by comparing preset values of these parameters. In addition, the differential relay functionality of fault detection was implemented in the Arduino environment. Whenever a fault occurred, Arduino sent the fault signal to a Wi-Fi module, which was then displayed in the Blynk app. The practical implementation of this proposed system was tested, and its operation was found to be effective in fault detection

Long-Term Monitoring of Soil Carbon Sequestration in Woody and Herbaceous Bioenergy Crop Production Systems on Marginal Lands in Southern Ontario, Canada

Enhancement of terrestrial carbon (C) sequestration on marginal lands in Canada using bioenergy crops has been proposed. However, factors influencing system-level C gain (SLCG) potentials of maturing bioenergy cropping systems, including belowground biomass C and soil organic carbon (SOC) accumulation, are not well documented. This study, therefore, quantified the long-term C sequestration potentials at the system-level in nine-year-old (2009–2018) woody (poplar clone 2293–29 (Populus spp.), hybrid willow clone SX-67 (Salix miyabeana)), and herbaceous (miscanthus (Miscanthus giganteus var. Nagara), switchgrass (Panicum virgatum)) bioenergy crop production systems on marginal lands in Southern Ontario, Canada. Results showed that woody cropping systems had significantly higher aboveground biomass C stock of 10.02 compared to 7.65 Mg C ha−1 in herbaceous cropping systems, although their belowground biomass C was not significantly different. Woody crops and switchgrass were able to increase SOC significantly over the tested period. However, when long term soil organic carbon (∆SOC) gains were compared, woody and herbaceous biomass crops gained 11.0 and 9.8 Mg C ha−1, respectively, which were not statistically different. Results also indicate a significantly higher total C pool [aboveground + belowground + soil organic carbon] in the willow (103 Mg ha−1) biomass system compared to other bioenergy crops. In the nine-year study period, woody crops had only 1.35 Mg C ha−1 more SLCG, suggesting that the influence of woody and herbaceous biomass crops on SLCG and ∆SOC sequestrations were similar. Further, among all tested biomass crops, willow had the highest annual SLCG of 1.66 Mg C ha−1 y−1

A nutrient-based sustainability assessment of purpose-grown poplar and switchgrass biomass production systems established on marginal lands in Canada

Sustainability of purpose-grown biomass production on marginal lands in Canada is uncertain. In this study, an assessment of biomass yield and sustainability was performed for two poplar clones (Poplus deltoides x P. nigra, DN-34 – PDN, and P. nigra x P. maximowiczii, NM-6 – PNM) and two switchgrass cultivars (Panicum virgatum cv. Cave-in-Rock – SGC, and Panicum virgatum cv. Nebraska – SGN) on three marginal lands in Guelph (Ontario), Kemptville (Ontario) and Nappan (Nova Scotia) in Canada. The differences in stem biomass across sites were not significant however, differences in stem biomass among plants were statistically significant between poplar and switchgrass (pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

The scientific value of the largest remaining old-growth red pine forests in North America

Old growth red pine forests (Pinus resinosa) cover less than 1% of their original range in North America and are essential for maintaining biodiversity at stand and landscape scales. Despite this, the largest remaining old-growth red pine forest in the world, the Wolf Lake Forest Reserve, is currently threatened by mining claims in Northern Ontario and has been receiving considerable media and public attention in recent months. We provide a timely review of how large old growth red pine forests maintain biodiversity at several taxonomic levels (with a focus on trees and plants) through heterogeneous partitioning of limiting resources such as light and nitrogen, formation of complex habitats through increased accumulation of coarse woody debris, and the maintenance of natural disturbance-driven succession. These processes shape the overstory community, allowing for the regeneration of pines, coexistence of early-mid successional shade intolerant species and cross-ecotonal establishment of late successional tree species in response to regional warming over the past three decades. Using Wolf Lake as a case study, we review legislation and policy complexities around this issue and provide scientific arguments for the preservation of this forest. We invoke recent insights into the ecological role of refugia, the development of criteria for assessing endangered ecosystems, and the challenges of conservation in the face of climate change and disturbance regimes. These forests are ecologically important and provide a scientifically irreplaceable system for assessing baseline ecosystem function, processes and services. As the largest remaining old-growth red pine forest in the world, Wolf Lake Forest Reserve deserves intensive study, monitoring and full protection from future development

An intensive tree-ring experience: Connecting education and research during the 25th European Dendroecological Fieldweek (Asturias, Spain).

The European Dendroecologial Fieldweek (EDF) provides an intensive learning experience in tree-ring research that challenges any participant to explore new multidisciplinary dendro-sciences approaches within the context of field and laboratory settings. Here we present the 25th EDF, held in Asturias, NW Spain, in summer 2014. The course, with 33 participants and 10 instructors from 18 countries included advanced training in dendrochronology skills, an overview of tree-ring broad fields and methodological basics to deal with specific research questions as well as applied advanced micro-projects in dendroarchaeology (DAR), dendroclimatology (DCL), dendrogeomorphology (DGM), forest dynamic (FD) and plant anatomy (PA). The results demonstrated the potential of tree-ring research in the Asturias region. The DAR group researched archaeological samples from different contexts (Oviedo cathedral choir stalls, Segovia cathedral roof timbers, Ribadeo shipwreck ship timbers and Bronze Age site charcoal) and explored the supply of wood in different periods. The DCL group established that the Quercus robur and Castanea sativa ring-width measurements show weak climate-growth correlations, where for many trees this is likely caused by management. The strength of the climatic signal could be enhanced using undisturbed settings. The DGM group found that Corylus avellana and Salix spp. are challenging species for dendrogeomorphological studies. Debris-flow events were detected by the presence of tension wood, growth reduction and scars, and their incidences were also supported by local meteorological data. The FD group found that tree growth decreases with increasing competition, a pattern more pronounced in C. sativa than in Pinus sylvestris forest plantations. The results indicate that wood production could be increased by applying thinning treatments on C. sativa. The PA group showed that xylem conduits and phloem area are organized according to the common needs for water supply to leaves and obtain photosynthetic products, regardless site growing conditions for P. sylvestris and Tusilago farfara. In conclusion, this EDF has been a model for interdisciplinary research and international collaboration that has demonstrated that high-quality research and education can be conducted within one week. The EDFs provide an important service to the dendrochronological community and demonstrate the usefulness of this educational-scientific and multi-cultural experience