Development of a simulation model of the forest–tundra transition zone of northeastern Canada

1994 ◽  
Vol 24 (4) ◽  
pp. 697-706 ◽  
Author(s):  
Luc Sirois ◽  
Gordon Blackwell Bonan ◽  
Herman Henry Shugart
Keyword(s):  
Forest Fires ◽  
Resource Constraints ◽  
Forest Succession ◽  
Black Spruce ◽  
Structural Characteristics ◽  
Fire Frequency ◽  
Lichen Woodland ◽  
Seed Regeneration ◽  
Gap Models ◽  
Subarctic Forest

A forest succession model has been adapted to simulate the dynamics of subarctic spruce–lichen woodland of northeastern Canada. Most adaptations concern the simulation of seed regeneration of subarctic forest communities growing on moderately to well drained sites. The yearly seed production in Piceamariana (Mill.) B.S.R stands is controlled by temperature and stand structural characteristics. In addition to the seed input, the model considers the influence of seedbed properties on the establishment of seedlings. Overall, this model simulates the entire regeneration dynamics in a more realistic way than in most other gap models where successional processes are driven by resource constraints on tree growth. The model produces realistic predictions about the pattern of early post-fire age structure, and the biomas and density dynamics of black spruce populations. Simulations under a climate-warming scenario suggest that physiognomic change in subarctic spruce–lichen woodland would be more pronounced in areas subjected to moderately frequent forest fires than in those where the fire frequency is very low.

scholarly journals An Environmentally Aware Scheme of Wireless Sensor Networks for Forest Fire Monitoring and Detection

2018 ◽  
Vol 10 (10) ◽  
pp. 102 ◽  
Author(s):  
Yi-Han Xu ◽  
Qiu-Ya Sun ◽  
Yu-Tong Xiao
Keyword(s):  
Wireless Sensor Networks ◽  
Energy Consumption ◽  
Sensor Networks ◽  
Forest Fire ◽  
Forest Fires ◽  
Network Architecture ◽  
Resource Constraints ◽  
Wireless Sensor ◽  
Surveillance Systems ◽  
Fire Monitoring

Forest fires are a fatal threat to environmental degradation. Wireless sensor networks (WSNs) are regarded as a promising candidate for forest fire monitoring and detection since they enable real-time monitoring and early detection of fire threats in an efficient way. However, compared to conventional surveillance systems, WSNs operate under a set of unique resource constraints, including limitations with respect to transmission range, energy supply and computational capability. Considering that long transmission distance is inevitable in harsh geographical features such as woodland and shrubland, energy-efficient designs of WSNs are crucial for effective forest fire monitoring and detection systems. In this paper, we propose a novel framework that harnesses the benefits of WSNs for forest fire monitoring and detection. The framework employs random deployment, clustered hierarchy network architecture and environmentally aware protocols. The goal is to accurately detect a fire threat as early as possible while maintaining a reasonable energy consumption level. ns-2-based simulation validates that the proposed framework outperforms the conventional schemes in terms of detection delay and energy consumption.

Portrait préindustriel dans un contexte de grande variabilité naturelle: une étude de cas dans le centre du Québec (Canada)

2011 ◽  
Vol 87 (05) ◽  
pp. 612-624 ◽  
Author(s):  
Eric Alvarez ◽  
Louis Bélanger ◽  
Louis Archambault ◽  
Frédéric Raulier
Keyword(s):  
Temperate Forest ◽  
Forest Cover ◽  
Sustainable Forest Management ◽  
Forest Succession ◽  
Black Spruce ◽  
Spatial Scales ◽  
White Birch ◽  
Industrial Landscape ◽  
Industrial Forest ◽  
Landscape Scales

Pre-industrial forest cover portrait is a recognized method for establishing the bases of sustainable forest management. However, it is a spatially and temporally dependant concept that should be used with caution in presence of big fires. The objective of the study was to portray the pre-industrial landscape in a mixedwood temperate forest in central Quebec at different spatial scales. The study was based on archival records from a forest company. The pre-industrial forest cover landscape of our study area was mainly composed of mature or old-growth (>100 years) stands and dominated by mixedwood forest stands with intolerant hardwoods. The main tree species were white birch, black spruce and jack pine, three species associated to forest succession after fire in the boreal forest. Considering the great variability caused by the fires and partial knowledge of this variability, for each spatial scale considered, we propose some management targets based on the main pre-industrial characteristics of this forest. To respect the pre-industrial variability, our study suggested that silviculture should be adapted at different landscape scales. Cover types and age class targets should be based on main preindustrial characteristics at each landscape scale analyzed.

Spatial dynamics of soil moisture and temperature in a black spruce boreal chronosequence

2006 ◽  
Vol 36 (11) ◽  
pp. 2794-2802 ◽  
Author(s):  
Ben Bond-Lamberty ◽  
Karen M Brown ◽  
Carol Goranson ◽  
Stith T Gower
Keyword(s):  
Soil Moisture ◽  
Spatial Variability ◽  
Sampling Design ◽  
Black Spruce ◽  
Structural Characteristics ◽  
Spatial Dynamics ◽  
Spherical Model ◽  
Local Scale ◽  
Spatial Dependencies ◽  
The Mean

This study analyzed the spatial dependencies of soil moisture and temperature in a six-stand chronosequence of boreal black spruce (Picea mariana (Mill.) BSP) stands. Spatial variability of soil temperature (TSOIL) was evaluated twice during the growing season using four transects in each stand, employing a cyclic sampling design with measurements spaced 2–92 m apart. Soil moisture (θg) was measured on one occasion. A spherical model was used to analyze the geostatistical correlation structure; θg and TSOIL at the 7- and 21-year-old stands did not exhibit stable ranges or sills. The fits with stable ranges and sills modeled the spatial patterns in the older stands reasonably well, although unexplained variability was high. Calculated ranges varied from 3 to 150 m for these stands, lengths probably related to structural characteristics influential in local-scale energy transfer. Transect-to-transect variability was significant and typically 5%–15% of the mean for TSOIL and 10%–70% for θg. TSOIL and θg were negatively correlated for most stands and depths, with TSOIL dropping 0.5–0.9 °C for every 1% rise in θg. The results reported here provide initial data to assess the spatial variability of TSOIL and θg in a variety of boreal forest stand ages.

Mission-Aware Adaptive Communication for Collaborative Mobile Entities

2011 ◽  
pp. 1056-1076 ◽  
Author(s):  
Jérôme Lacouture ◽  
Ismael Bouassida Rodriguez ◽  
Jean-Paul Arcangeli ◽  
Christophe Chassot ◽  
Thierry Desprats ◽  
...  
Keyword(s):  
Forest Fires ◽  
Communication System ◽  
Resource Constraints ◽  
New Concepts ◽  
Wireless Environment ◽  
First Results ◽  
Collaborative Activities ◽  
Human Actors ◽  
Communication Resource

Adaptation of communication is needed to maintain the connectivity and quality of communication in group-wide collaborative activities. This becomes quite a challenge to handle when mobile entities are part of a wireless environment, in which responsiveness and availability of the communication system are required. In this chapter, these challenges are addressed within the context of the ROSACE project where mobile ground and flying robots have to collaborate either between them selves or with remote artificial and human actors during save and rescue missions in the event of disasters such as forest fires. This chapter presents our first results. The final goal is to propose new concepts, models and architectures that supports cooperative adaptation which is aware of the mission being executed. Thus, the communication system can be adequately adapted in response to predictable or unpredictable evolutions of the activity requirements and to the unpredictable changes in the communication resource constraints.

Summary and Synthesis: Past and Future Changes in the Alaskan Boreal Forest

2006 ◽  
Author(s):  
Marilyn W. Walker ◽  
Mary E. Edwards
Keyword(s):  
Boreal Forest ◽  
Bark Beetles ◽  
Fire Regime ◽  
Black Spruce ◽  
Rapid Change ◽  
White Spruce ◽  
Late Glacial ◽  
Fire Frequency ◽  
Tree Resistance ◽  
Forest Sites

Historically the boreal forest has experienced major changes, and it remains a highly dynamic biome today. During cold phases of Quaternary climate cycles, forests were virtually absent from Alaska, and since the postglacial re-establishment of forests ca 13,000 years ago, there have been periods of both relative stability and rapid change (Chapter 5). Today, the Alaskan boreal forest appears to be on the brink of further significant change in composition and function triggered by recent changes that include climatic warming (Chapter 4). In this chapter, we summarize the major conclusions from earlier chapters as a basis for anticipating future trends. Alaska warmed rapidly at the end of the last glacial period, ca 15,000–13,000 years ago. Broadly speaking, climate was warmest and driest in the late glacial and early Holocene; subsequently, moisture increased, and the climate gradually cooled. These changes were associated with shifts in vegetation dominance from deciduous woodland and shrubland to white spruce and then to black spruce. The establishment of stands of fire-prone black spruce over large areas of the boreal forest 5000–6000 years ago is linked to an apparent increase in fire frequency, despite the climatic trend to cooler and moister conditions. This suggests that long-term features of the Holocene fire regime are more strongly driven by vegetation characteristics than directly by climate (Chapter 5). White spruce forests show decreased growth in response to recent warming, because warming-induced drought stress is more limiting to growth than is temperature per se (Chapters 5, 11). If these environmental controls persist, projections suggest that continued climate warming will lead to zero net annual growth and perhaps the movement of white spruce to cooler upland forest sites before the end of the twenty-first century. At the southern limit of the Alaskan boreal forest, spruce bark beetle outbreaks have decimated extensive areas of spruce forest, because warmer temperatures have reduced tree resistance to bark beetles and shortened the life cycle of the beetle from two years to one, shifting the tree-beetle interaction in favor of the insect (Chapter 9).

scholarly journals Can Carbon Sequestration in Tasmanian “Wet” Eucalypt Forests Be Used to Mitigate Climate Change? Forest Succession, the Buffering Effects of Soils, and Landscape Processes Must Be Taken into Account

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Peter D. McIntosh ◽  
James L. Hardcastle ◽  
Tobias Klöffel ◽  
Martin Moroni ◽  
Talitha C. Santini
Keyword(s):  
Climate Change ◽  
Forest Fires ◽  
Forest Succession ◽  
Mixed Forest ◽  
Mixed Forests ◽  
Soil C ◽  
C Stocks ◽  
Mitigate Climate Change ◽  
Eucalypt Forests

Small areas of the wetter parts of southeast Australia including Tasmania support high-biomass “wet” eucalypt forests, including “mixed” forests consisting of mature eucalypts up to 100 m high with a rainforest understorey. In Tasmania, mixed forests transition to lower biomass rainforests over time. In the scientific and public debate on ways to mitigate climate change, these forests have received attention for their ability to store large amounts of carbon (C), but the contribution of soil C stocks to the total C in these two ecosystems has not been systematically researched, and consequently, the potential of wet eucalypt forests to serve as long-term C sinks is uncertain. This study compared soil C stocks to 1 m depth at paired sites under rainforest and mixed forests and found that there was no detectable difference of mean total soil C between the two forest types, and on average, both contained about 200 Mg·ha−1 of C. Some C in subsoil under rainforests is 3000 years old and retains a chemical signature of pyrogenic C, detectable in NMR spectra, indicating that soil C stocks are buffered against the effects of forest succession. The mean loss of C in biomass as mixed forests transition to rainforests is estimated to be about 260 Mg·ha−1 over a c. 400-year period, so the mature mixed forest ecosystem emits about 0.65 Mg·ha−1·yr−1 of C during its transition to rainforest. For this reason and because of the risk of forest fires, setting aside large areas of wet eucalypt forests as reserves in order to increase landscape C storage is not a sound strategy for long-term climate change mitigation. Maintaining a mosaic of managed native forests, including regenerating eucalypts, mixed forests, rainforests, and reserves, is likely to be the best strategy for maintaining landscape C stocks.

Fuel characteristics and fire behaviour in mature Mediterranean gorse shrublands

2004 ◽  
Vol 13 (1) ◽  
pp. 79 ◽  
Author(s):  
Martín De Luis ◽  
Manuel J. Baeza ◽  
José Raventós ◽  
José C. González-Hidalgo
Keyword(s):  
Forest Fires ◽  
Plant Density ◽  
Structural Characteristics ◽  
Fire Severity ◽  
Fire Behaviour ◽  
Fuel Distribution ◽  
Degree Of Dominance ◽  
Mediterranean Regions ◽  
The Relationship

Since the early 1990s, Mediterranean gorse shrublands have expanded significantly in the Mediterranean regions of Spain mainly as a result of the increase in the frequency and extension of forest fires. Mediterranean gorse (Ulex parviflorus), which has been described as a degradation stage of forest communities after fire, has also been described as a fire-prone community. Thus, its presence increases the risk that new fires might occur. In spite of this evidence, there is little information on both the composition and structural characteristics of these communities or the relationship that might exist between these vegetation characteristics and fire behaviour. In this paper we present the results of a characterization of the vegetative structure (plant density, specific composition, biomass fractions, and horizontal and vertical fuel distribution) in Mediterranean gorse. We also analyse fire behaviour using indicators obtained at different scales. Our results show mature Mediterranean gorse shrublands to be communities with high biomass values (3000–4000 g m−2) and high horizontal and vertical vegetation continuity, in which the proportion of fine dead fuel fractions with low moisture content is around 50% of the total phytomass present. Ulex parviflorus is the dominant species and its degree of dominance is a key element in the behaviour of fire. Both the fire-line intensity values and the fire severity values observed can be considered high with respect to those observed in other Mediterranean communities, thus confirming Mediterranean gorse as a high-risk community.

Fire history and its drivers based on peatland charcoal analysis in the Changbai Mountains, north-east China, during the last 13 000 years

2020 ◽  
Vol 29 (9) ◽  
pp. 841
Author(s):  
Meng Meng ◽  
Dongmei Jie ◽  
Dehui Li ◽  
Nannan Li ◽  
Baojian Liu ◽  
...  
Keyword(s):  
Forest Fires ◽  
Fire History ◽  
Regional Scale ◽  
Fire Frequency ◽  
Changbai Mountains ◽  
Mountain Forest ◽  
Archaeological Data ◽  
The Past ◽  
North East ◽  
Strict Regulation

The Changbai Mountains forest ecosystem is one of the best-preserved temperate mountain forest ecosystems in Asia. Since the establishment of the reserve in 1960, extensive forest fires have been excluded as a result of strict regulation and suppression efforts and thus fuels have accumulated for several decades. Due to the lack of historical fire records in the area, the risk of fire occurrence cannot be properly estimated. In this study, we used charcoal records to reconstruct the palaeo-fire frequency in the Changbai Mountains during the last 13000 years. The results indicate that fires were frequent during 13.0–11.0, 7.0–6.0, and 2.5–2.0 calender (cal) kyr before present (BP) and from 1.0 cal kyr BP to the present. The fire frequencies are largely consistent with other palaeoenvironmental records from the study area and we conclude that since 13.0 cal kyr BP fires were more frequent at the regional scale during intervals of a weak summer monsoon, caused by a cold and dry climate and the abundance of flammable trees. Archaeological data from the study area since 3.0 cal kyr BP indicate increasing human activity, which dominated the occurrence of local fires. In addition, intermittent volcanic activity influenced the occurrence of fires during the past millennium.

scholarly journals Lessons learned from 12 years of ecological research on partial cuts in black spruce forests of northwestern Québec

2013 ◽  
Vol 89 (03) ◽  
pp. 350-359 ◽  
Author(s):  
Nicole J. Fenton ◽  
Louis Imbeau ◽  
Timothy Work ◽  
Jenna Jacobs ◽  
Hervé Bescond ◽  
...  
Keyword(s):  
Forest Succession ◽  
Black Spruce ◽  
Basal Area ◽  
Forest Harvesting ◽  
Lessons Learned ◽  
Future Research ◽  
Spruce Forests ◽  
Partial Harvest ◽  
Species Groups ◽  
The Impact

Multi-cohort management that creates or maintains an uneven structure within forest stands has been widely advocated as a means to attenuate the impact of forest harvesting. An experimental network was put in place in black spruce forests of northwestern Québec to test this assertion. Here we synthesize the biodiversity results in two main lessons: (1) at least 40% to 60% retention of pre-harvest basal area was required to maintain pre-harvest conditions for most species groups; (2) partial harvests showed the potential to be efficient deadwood delivery systems. In addition to these two main general conclusions, we emphasise that future research should examine whether partial harvest may be able to advance forest succession.

Dimension analysis of various components of black spruce in subarctic lichen woodland

1980 ◽  
Vol 10 (4) ◽  
pp. 491-497 ◽  
Author(s):  
Andrew N. Rencz ◽  
Allan N. Auclair
Keyword(s):  
Parabolic Equations ◽  
Individual Component ◽  
Black Spruce ◽  
Eastern Canada ◽  
Data Set ◽  
Dimension Analysis ◽  
Closed Forest ◽  
Lichen Woodland ◽  
Parabolic Form ◽  
Total Tree

Parabolic and logarithmic regressions were used to relate tree diameter to the biomass of root, root crown, bole, branch, needle, cone, and epiphytic lichens for a sample of 15 Piceamariana (Mill) trees occupying lichen woodland in the subarctic of eastern Canada. In 22 of 27 regressions both models yielded r2 values >0.82. Biomass estimates of total tree and individual component dry weights resulted in estimates with less than 6.5% difference between biomass estimates by logarithmic versus parabolic equations. For this data set the logarithmic model appeared more appropriate than the parabolic form. Validity of the regressions was judged on r2, analysis of variance, and examination of residuals. Equations generated in this study were considered to be inapplicable to P. mariana growing in closed forest. Problems in extrapolation were discussed.

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