Search results for "forestry"
showing 10 items of 1998 documents
The impact of beaver dam removal on the chemical properties of water in drainage ditches in peatland forests
2020
Despite near-extinction in the nineteenth century, after efficient restoration measures the population of Eurasian beaver (Castor fiber L.) in Latvia currently is viable and growing. While the ecol...
Evaluation of geomorphometric characteristics and soil properties after a wildfire using Sentinel-2 MSI imagery for future fire-safe forest
2021
Abstract Understanding spatiotemporal geomorphological and pedological changes as a consequence of wildfires can allow stakeholders, land planners, and policymakers to design efficient fire safety-based afforestation and restoration programs of forest lands. The use of remote sensing techniques is a key tool to achieve this goal. The suitable combination of Sentinel-2 MSI data for mapping of different spectral indices related to burn severity and their relationship with other morphometric and soil properties can contribute to a better understanding of the impact of fire, and this is relevant in regions where is still scarce fire-related research such as Turkey. In this investigation, the us…
Modeling of biomass smoke injection into the lower stratosphere by a large forest fire (Part II): Sensitivity studies
2006
Abstract. The Chisholm forest fire that burned in Alberta, Canada, in May 2001 resulted in injection of substantial amounts of smoke into the lower stratosphere. We used the cloud-resolving plume model ATHAM (Active Tracer High resolution Atmospheric Model) to investigate the importance of different contributing factors to the severe intensification of the convection induced by the Chisholm fire and the subsequent injection of biomass smoke into the lower stratosphere. The simulations show strong sensitivity of the pyro-convection to background meteorology. This explains the observed coincidence of the convective blow-up of the fire plume and the passage of a synoptic cold front. Furthermor…
Financial contagion through space-time point processes
2020
AbstractWe propose to study the dynamics of financial contagion by means of a class of point process models employed in the modeling of seismic contagion. The proposal extends network models, recently introduced to model financial contagion, in a space-time point process perspective. The extension helps to improve the assessment of credit risk of an institution, taking into account contagion spillover effects.
Evaluating a hierarchical approach to landscape-level harvest scheduling
2018
Forest planning at the landscape level has the potential to become a large intractable problem. In Finland, Metsähallitus (the state enterprise that manages federally owned land) creates strategic plans to determine the appropriate harvest level. While these plans are feasible, they are not implementable in practice as the harvests are scattered temporally and spatially. Requiring that harvests be organized both temporally and spatially for practical implementation can result in an intractable problem. Through a hierarchical approach, the problem can be organized into steps in which the intractable problem is broken down into smaller easily solvable parts. As an approximation technique, th…
A competing risks tale on successful and unsuccessful fiscal consolidations
2019
Abstract This paper analyses the transitions out of fiscal consolidations using annual data for 17 industrial countries over the period 1975-2013 and applying a discrete-time competing risks duration model. Our approach allows us to distinguish the factors behind a successful or an unsuccessful end of fiscal consolidation episodes. The results show that economic and political factors, the size and typology of fiscal adjustments and the occurrence of crises explain the differences in the length and the success/failure of fiscal consolidations. Moreover, while fiscal adjustment programmes that end successfully display positive duration dependence, those that end in an unsuccessful manner are …
Use of Wood Ash in the Forest and its Effect on the Concentration of Essential and Heavy Metallic Elements in Soil and Blueberries <i>(Vacciniu…
2020
The aim of this research is to evaluate the influence of wood ash as an additive fertilizer to forest soil and growing blueberries (Vaccinium myrtillus L.) in terms of metallic element content. To evaluate the effect of wood ash on the forest ecosystem, was selected two forest areas which was fertilized with a certain amount of wood ash (bottom ash and fly ash). The selected forest areas were divided into two types of sampling plots (fertilized with ash and control). Obtained results showed that in the bottom ash dispersion area the concentration of Ca, K, Ni, Cu is almost twice higher in the fertilized plots than control plots. In the blueberries, metallic element content is similar and do…
A reactive nitrogen budget for forest land and wetlands in Latvia and Estonia
2020
Human intervention in global nitrogen cycling has led to excess reactive nitrogen (Nr) flows to the environment, impacting terrestrial ecosystems as well as the quality of the atmosphere and waterb...
Adsorption et desorption de la terbutryne par une montmorillonite-Ca et des acides humiques seuls ou en melanges
1977
Resume: L' effet du pH sur l'adsorption de la terbutryne par des acides humiques, une montmorillonite-Ca ou leurs melanges montre une certaine similitude de comportement entre ces derniers et l'argile seule. Au voisinage de la neutralite, seuls les acides humiques adsorbent la terbutryne. En milieu acide, les isothermes d'adsorption de la terbutryne par les acides humiques et la montmorillonite sont respectivement de type L et S et traduisent une affinite adsorbat-adsorbant differente; les isothermes d'adsorption correspondant aux melanges ont une forme differente et font apparaitre un effet de synergie, en particulier dans le cas des melanges pauvres en acides humiques. La dsorption saccom…
Proactive avoidance behaviour and pace-of-life syndrome in Atlantic salmon
2019
Individuals in a fish population differ in key life-history traits such as growth rate and body size. This raises the question of whether such traits cluster along a fast-slow growth continuum according to a pace-of-life syndrome (POLS). Fish species like salmonids may develop a bimodal size distribution, providing an opportunity to study the relationships between individual growth and behavioural responsiveness. Here we test whether proactive characteristics (bold behaviour coupled with low post-stress cortisol production) are related to fast growth and developmental rate in Atlantic salmon, Salmo salar . Boldness was tested in a highly controlled two-tank hypoxia test were oxygen levels …