scholarly journals Utikuma Region Study Area (URSA) – Part 1: Hydrogeological and ecohydrological studies (HEAD)

2016 ◽  
Vol 92 (01) ◽  
pp. 57-61 ◽  
Author(s):  
Kevin J. Devito ◽  
Carl Mendoza ◽  
Richard M. Petrone ◽  
Nick Kettridge ◽  
James M. Waddington
Keyword(s):  
Boreal Forest ◽  
Conceptual Understanding ◽  
Natural Disturbance ◽  
Spatially Explicit ◽  
Forest Research ◽  
Boreal Plains ◽  
Process Studies ◽  
Hydrogeological Studies ◽  
Western Boreal Forest

The Utikuma Region Study Area (URSA) was initiated to develop spatially explicit modelling tools to predict the cumulative impacts of land use and natural disturbance on the Boreal Plains (BP) ecozone of the Western Boreal Forest. Research comprised several multi-year projects, spanning wet and dry climate periods that combined intensive detailed process studies at seven watersheds with extensive long-term ecohydrological and hydrogeological studies conducted across a 60-km transect representing the range of glaciated landforms characteristic of the sub-humid boreal forest in Alberta. These studies have improved our conceptual understanding and capacity to numerically model how climate and geology influence water and energy flow, and the hydrologic linkages and natural variability of the key processes influencing BP ecosystems. Eco-hydrogeological frameworks have been developed for designing, conducting, interpreting, and extrapolating research results for watershed management and construction across the Boreal Plain ecozone.

Using spatially explicit simulations to explore size distribution and spacing of regenerating areas produced by wildfires: recommendations for designing harvest agglomerations for the Canadian boreal forest

2007 ◽  
Vol 83 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Annie Belleau ◽  
Yves Bergeron ◽  
Alain Leduc ◽  
Sylvie Gauthier ◽  
Andrew Fall
Keyword(s):  
Forest Management ◽  
Boreal Forest ◽  
Size Distribution ◽  
Temporal Variability ◽  
Fire Regime ◽  
Natural Disturbance ◽  
Fire Regimes ◽  
Spatially Explicit ◽  
Fire Size ◽  
Canadian Boreal Forest

It is now recognized that in the Canadian boreal forest, timber harvesting activities have replaced wildfires as the main stand-replacing disturbance. Differences in landscape patterns derived from these two sources of disturbance have, however, raised concerns that the way forest harvesting has been dispersed is potentially shifting patterns away from the natural range. In the context of natural disturbance-based management, we used a spatially explicit model designed to capture general fire regimes in order to quantify temporal variability associated with regenerating areas (burnt areas of 25 years or younger), and to develop strategic objectives for harvest agglomeration sizes and dispersion. We first evaluated temporal variability in the proportion of stands younger than 100 years (assumed to be even-aged stands) for various fire regimes (seven fire cycles: 50 to 400 years, and three mean fires sizes: 3000, 15 000 and 60 000 ha). Secondly, we quantified the size distribution and dispersion of regenerating areas for each fire regime. As expected by theoretical fire frequencies and size distributions, the importance of even-aged stands at the forest management unit level was found to decrease with longer fire cycles. However, the temporal variability associated with these proportions is shown to increase with mean fire size. It was also observed that the size distribution and dispersion of regenerating areas was primarily influenced by mean fire size. Based on these observations, natural disturbance-based management objectives were formulated, providing guidelines on harvest agglomeration size and dispersion. Key words: temporal variability, boreal forest, fire regime, forest management, age distribution, fire size distribution, clearcut agglomeration size distribution

scholarly journals Leopard Density Estimation within an Enclosed Reserve, Namibia Using Spatially Explicit Capture-Recapture Models

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 724
Author(s):  
Noack ◽  
Heyns ◽  
Rodenwoldt ◽  
Edwards
Keyword(s):  
Management Strategies ◽  
Camera Traps ◽  
Spatially Explicit ◽  
Conservation Areas ◽  
Term Survival ◽  
New Class ◽  
Capture Recapture ◽  
Wildlife Populations ◽  
Effective Conservation

The establishment of enclosed conservation areas are claimed to be the driving force for the long-term survival of wildlife populations. Whilst fencing provides an important tool in conservation, it simultaneously represents a controversial matter as it stops natural migration processes, which could ultimately lead to inbreeding, a decline in genetic diversity and local extinction if not managed correctly. Thus, wildlife residing in enclosed reserves requires effective conservation and management strategies, which are strongly reliant on robust population estimates. Here, we used camera traps combined with the relatively new class of spatially explicit capture-recaptured models (SECR) to produce the first reliable leopard population estimate for an enclosed reserve in Namibia. Leopard density was estimated at 14.51 leopards/100 km2, the highest recorded density in Namibia to date. A combination of high prey abundance, the absence of human persecution and a lack of top-down control are believed to be the main drivers of the recorded high leopard population. Our results add to the growing body of literature which suggests enclosed reserves have the potential to harbour high densities and highlight the importance of such reserves for the survival of threatened species in the future.

Long-term dynamic modeling of global population and built-up area in a spatially explicit way: HYDE 3.1

The Holocene ◽  
2010 ◽  
Vol 20 (4) ◽  
pp. 565-573 ◽  
Author(s):  
Kees Klein Goldewijk ◽  
Arthur Beusen ◽  
Peter Janssen
Keyword(s):  
Dynamic Modeling ◽  
Spatially Explicit ◽  
Global Population

scholarly journals Effects of lightning and other meteorological factors on fire activity in the North American boreal forest: implications for fire weather forecasting

2010 ◽  
Vol 10 (14) ◽  
pp. 6873-6888 ◽  
Author(s):  
D. Peterson ◽  
J. Wang ◽  
C. Ichoku ◽  
L. A. Remer
Keyword(s):  
Boreal Forest ◽  
North American ◽  
Meteorological Factors ◽  
Convective Available Potential Energy ◽  
Fire Weather ◽  
Lightning Strikes ◽  
The North ◽  
Lightning Detection ◽  
Western Boreal Forest ◽  
Consecutive Dry Days

Abstract. The effects of lightning and other meteorological factors on wildfire activity in the North American boreal forest are statistically analyzed during the fire seasons of 2000–2006 through an integration of the following data sets: the MODerate Resolution Imaging Spectroradiometer (MODIS) level 2 fire products, the 3-hourly 32-km gridded meteorological data from North American Regional Reanalysis (NARR), and the lightning data collected by the Canadian Lightning Detection Network (CLDN) and the Alaska Lightning Detection Network (ALDN). Positive anomalies of the 500 hPa geopotential height field, convective available potential energy (CAPE), number of cloud-to-ground lightning strikes, and the number of consecutive dry days are found to be statistically important to the seasonal variation of MODIS fire counts in a large portion of Canada and the entirety of Alaska. Analysis of fire occurrence patterns in the eastern and western boreal forest regions shows that dry (in the absence of precipitation) lightning strikes account for only 20% of the total lightning strikes, but are associated with (and likely cause) 40% of the MODIS observed fire counts in these regions. The chance for ignition increases when a threshold of at least 10 dry strikes per NARR grid box and at least 10 consecutive dry days is reached. Due to the orientation of the large-scale pattern, complex differences in fire and lightning occurrence and variability were also found between the eastern and western sub-regions. Locations with a high percentage of dry strikes commonly experience an increased number of fire counts, but the mean number of fire counts per dry strike is more than 50% higher in western boreal forest sub-region, suggesting a geographic and possible topographic influence. While wet lightning events are found to occur with a large range of CAPE values, a high probability for dry lightning occurs only when 500 hPa geopotential heights are above ~5700 m and CAPE values are near the maximum observed level, underscoring the importance of low-level instability to boreal fire weather forecasts.

scholarly journals Overview of a prescribed burning experiment within a boreal forest in Finland

2013 ◽  
Vol 13 (8) ◽  
pp. 21703-21763 ◽  
Author(s):  
A. Virkkula ◽  
J. Levula ◽  
T. Pohja ◽  
P. P. Aalto ◽  
P. Keronen ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Radiative Forcing ◽  
Prescribed Burning ◽  
Geometric Mean ◽  
Sonic Anemometer ◽  
Ground Level ◽  
Organic Layer ◽  
Available Nitrogen ◽  
Mean Diameter

Abstract. A prescribed burning of a boreal forest was conducted on 26 June 2009 in Hyytiälä, Finland, to study aerosol and trace gas emissions from wildfires and the effects of fire on soil properties in a controlled environment. A 0.8 ha forest near the SMEAR II was cut clear; some tree trunks, all tree tops and branches were left on the ground and burned. The amount of burned organic material was ~46.8 t (i.e., ~60 t ha−1). The flaming phase lasted 2 h 15 min, the smoldering phase 3 h. Measurements were conducted on the ground with both fixed and mobile instrumentation, and from a research aircraft. In the middle of the burning area, CO2 concentration peaks were around 2000–3000 ppm above the baseline and peak vertical flow velocities were 6 ± 3 m s−1, as measured a 10-Hz 3-D sonic anemometer placed within the burn area. Peak particle number concentrations were approximately 1–2 × 106 cm−3 in the plume at a distance of 100–200 m from the burn area. The geometric mean diameter of the mode with the highest concentration was at 80 ± 1 nm during the flaming phase and in the middle of the smoldering phase but at the end of the smoldering phase the largest mode was at 122 nm. In the volume size distributions geometric mean diameter of the largest volume mode was at 153 nm during the flaming phase and at 300 nm during the smoldering phase. The lowest single-scattering albedo of the ground-level measurents was 0.7 in the flaming-phase plume and ~0.9 in the smoldering phase. The radiative forcing efficiency was negative above dark surfaces, in other words, the particles cool the atmosphere. Elevated concentrations of several VOCs (including acetonitrile which is a biomass burning marker) were observed in the smoke plume at ground level. The forest floor (i.e., richly organic layer of soil and debris, characteristic of forested land) measurements showed that VOC fluxes were generally low and consisted mainly of monoterpenes, but a clear peak of VOC flux was observed after the burning. After one year, the fluxes were nearly stabilised close to the level before the burning. The clearcutting and burning of slash increased the total long-term CO2 release from the soil, altered the soil's physical, chemical and biological properties such as increased the available nitrogen contents of the soil, which in turn, affected the level of the long-term fluxes of greenhouse gases.

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