An approach for assessing suitability for forest management based on constraints of the physical environment at a regional scale

2015 ◽  
Vol 45 (5) ◽  
pp. 529-539 ◽  
Author(s):  
André Robitaille ◽  
Jean-Pierre Saucier ◽  
Michel Chabot ◽  
Damien Côté ◽  
Catherine Boudreault

Constraints of the physical environment affect forest growth and forest operations. At a local scale, these constraints are generally considered during forest operations. At regional or continental scales, they are often integrated to larger assessments of the potential for a given land unit to be managed. In this study, we propose an approach to analyze the integration of physical-environment constraints in forest management activities at the regional scale (482 000 km2). The land features that pose constraints to forest management (i.e., hydromorphic organic deposits, dead-ice moraines, washed till, glacial block fields, talus, and active aeolian deposits, slopes > 40%) were evaluated within 1114 land districts. To distinguish land districts that can be suitably managed from those where constraints are too important for sustainable timber production, we carried out a sensitivity analysis of physical constraints for the 1114 land districts. After analysis of two portions of the study area under management, a land district was considered suitable for management when more than 20% of its land area consists of features imposing few constraints or, for mountain-type relief districts, when more than 40% of the land area consists of features imposing few constraints. These cutoff values were defined by expert opinion, based on sensitivity analyses performed on the entire study area, on analyses of two different sectors with different types of constraints and on a strong understanding of the study area. Our results show that land districts where the physical environment posed significant constraints covered 7.5% of the study area (36 000 km2). This study shows that doing an a priori classification of land units based on permanent environmental features could facilitate the identification of areas that are not suitable for forest management activities.

2003 ◽  
Vol 154 (8) ◽  
pp. 305-313 ◽  
Author(s):  
Roman Eyholzer ◽  
Martin Baumann ◽  
Rolf Manser

Faced with the challenging task of balancing forest interests and wildlife, the Swiss Forest Agency initiated the pilot programme«Game and Forest», which is committed to a philosophy of goal-oriented management practice and a redesign of forestry subsidizing. Within this programme the diverse goals of forestry and hunting have been amalgamated to a superimposed goal and set out in a corresponding contract. The Game-Forest-Management-Tool (GFMT) has been divised to simulate the effect of various strategies to deal with the complex problems of forest-wildlife. Optimal contract-fulfilling procedures can be simulated on a PC using this technical tool. The efficiency of the measures suggested by simulations that were carried out are being tested in a study area within the pilot programme, «Game and Forest». Half way through this trial, after two years, we can say that there has been no significant increase of non-browsed areas. In 2004, after the collection of data for the entire study area, we will be able to tell whether applying this computer simulated strategy truly leads to an augmentation of non-browsed area and a decrease in bark-peeled forests in the pilot area.


SIMULATION ◽  
2020 ◽  
Vol 96 (8) ◽  
pp. 641-653
Author(s):  
Jonathan Larson ◽  
Paul Isihara ◽  
Gabriel Flores ◽  
Edwin Townsend ◽  
Danilo R. Diedrichs ◽  
...  

The United Nations Office for the Coordination of Humanitarian Affairs has asserted that risks in deployment of unmanned aerial vehicles (UAVs) within disaster response must be reduced by careful development of best-practice standards before implementing such systems. With recent humanitarian field tests of cargo UAVs as indication that implementation may soon become reality, a priori assessment of a smart-navigated (autonomous) UAV disaster cargo fleet via simulation modeling and analysis is vital to the best-practice development process. Logistical problems with ground transport of relief supplies in Puerto Rico after Hurricane Maria (2017) pose a compelling use scenario for UAV disaster cargo delivery. In this context, we introduce a General Purpose Assessment Model (GPAM) that can estimate the potential effectiveness of a cargo UAV fleet for any given response region. We evaluate this model using the following standards: (i) realistic specifications; (ii) stable output for various realistic specifications; and (iii) support of humanitarian goals. To this end, we discuss data from humanitarian cargo delivery field tests and feedback from practitioners, perform sensitivity analyses, and demonstrate the advantage of using humanitarian rather than geographic distance in making fleet delivery assignments. We conclude with several major challenges faced by those who wish to implement smart-navigated UAV cargo fleets in disaster response, and the need for further GPAM development. This paper proposes the GPAM as a useful simulation tool to encourage and guide steps toward humanitarian use of UAVs for cargo delivery. The model’s flexibility can allow organizations to quickly and effectively determine how best to respond to disasters.


Britain possesses a forest area which is one of the smallest in Europe in relation to its population and land area. In the past, forests have been felled to make way for farming and to supply timber for ships, houses, fuel and metal smelting. Timber was a key to sea power, and repeatedly the availability of home timber supplies has proved crucial in time of war. The nation’s dwindling reserves of timber have been a source of anxiety since Tudor times and periodic surges of planting for timber production by private landowners took place until about 1850. Thereafter, interest faded with the advent of the iron ship, the Industrial Revolution and the availability of cheap timber imports. Govern­ ment activity was minimal until a national forest authority was formed in 1919 to create a strategic timber reserve. Since 1958 there have been frequent policy reviews to assess the changing needs of the nation for timber and the new values associated with the social and environmental benefits of forests.


Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 8
Author(s):  
Bruno L. De Faria ◽  
Gina Marano ◽  
Camille Piponiot ◽  
Carlos A. Silva ◽  
Vinícius de L. Dantas ◽  
...  

In recent decades, droughts, deforestation and wildfires have become recurring phenomena that have heavily affected both human activities and natural ecosystems in Amazonia. The time needed for an ecosystem to recover from carbon losses is a crucial metric to evaluate disturbance impacts on forests. However, little is known about the impacts of these disturbances, alone and synergistically, on forest recovery time and the resulting spatiotemporal patterns at the regional scale. In this study, we combined the 3-PG forest growth model, remote sensing and field derived equations, to map the Amazonia-wide (3 km of spatial resolution) impact and recovery time of aboveground biomass (AGB) after drought, fire and a combination of logging and fire. Our results indicate that AGB decreases by 4%, 19% and 46% in forests affected by drought, fire and logging + fire, respectively, with an average AGB recovery time of 27 years for drought, 44 years for burned and 63 years for logged + burned areas and with maximum values reaching 184 years in areas of high fire intensity. Our findings provide two major insights in the spatial and temporal patterns of drought and wildfire in the Amazon: (1) the recovery time of the forests takes longer in the southeastern part of the basin, and, (2) as droughts and wildfires become more frequent—since the intervals between the disturbances are getting shorter than the rate of forest regeneration—the long lasting damage they cause potentially results in a permanent and increasing carbon losses from these fragile ecosystems.


2021 ◽  
pp. 36-47
Author(s):  
Sergey Mitsyn ◽  
Egor Bolshakov

Various methods based on growing bodies are lately gaining attention in a context of inverse gravity problem that we call a family of “assembly methods”. A variant of method was adopted for GIS INTEGRO in original formulation that is fit for the problem of multiple bodies incorporated in an environment of varying density, in absolute densities (not density contrasts) that are however have to be a priori specified. Such formulation allowed the implementation of the method that is suitable for territory modeling in the regional scale. To workaround method’s instability a number of changes are proposed that consist of introduction of priority on atomic modifications, modification queue and assessment of model evolution instead of just the final result. The developed software allows processing of large grids (tens of millions of tiling elements) even on 5–8 year old desktops. Based on method approbation experience some insights and practice methods are presented. An application example is presented as part of work on modeling of Enisei-Khatanga regional depression territory.


2008 ◽  
Vol 23 (5) ◽  
pp. 431-444 ◽  
Author(s):  
Kati Vierikko ◽  
Seppo Vehkamäki ◽  
Jari Niemelä ◽  
Jani Pellikka ◽  
Harto Lindén

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1181
Author(s):  
Guy R. Larocque ◽  
F. Wayne Bell

Environmental concerns and economic pressures on forest ecosystems have led to the development of sustainable forest management practices. As a consequence, forest managers must evaluate the long-term effects of their management decisions on potential forest successional pathways. As changes in forest ecosystems occur very slowly, simulation models are logical and efficient tools to predict the patterns of forest growth and succession. However, as models are an imperfect representation of reality, it is desirable to evaluate them with historical long-term forest data. Using remeasured tree and stand data from three data sets from two ecoregions in northern Ontario, the succession gap model ZELIG-CFS was evaluated for mixed boreal forests composed of black spruce (Picea mariana [Mill.] B.S.P.), balsam fir (Abies balsamea [L.] Mill.), jack pine (Pinus banksiana L.), white spruce (Picea glauca [Moench] Voss), trembling aspen (Populus tremuloides Michx.), white birch (Betula papyrifera Marsh.), northern white cedar (Thuja occidentalis L.), American larch (Larix laricina [Du Roi] K. Koch), and balsam poplar (Populus balsamefera L.). The comparison of observed and predicted basal areas and stand densities indicated that ZELIG-CFS predicted the dynamics of most species consistently for periods varying between 5 and 57 simulation years. The patterns of forest succession observed in this study support gap phase dynamics at the plot scale and shade-tolerance complementarity hypotheses at the regional scale.


Author(s):  
Kezang Choden ◽  
Bhagat Suberi ◽  
Purna Chettri

Forests are natural carbon reservoirs that play an important role in the global carbon cycle for storing large quantities of carbon in vegetation and soils. Carbon stored in pool helps in mitigating climate change by carbon sequestration. The vulnerable countries to changing climate such as Bhutan, Nepal, and India require a full understanding of carbon dynamics as well as baseline data on carbon stock potential to mitigate anticipated risks and vulnerabilities (RVs) through climate change. The scope of such RVs are trans boundary in nature, however, the comparative studies at regional scale are still scanty. Therefore, the aim of this review is to assess the carbon stock potentials of selected forest types in the eastern Himalayan area, with an emphasis on Bhutan, India, and Nepal. This review paper is based on published articles, information from websites and considerable data from National forestry reports of India and Bhutan; emphasizing on aboveground biomass and soil organic carbon stock. The review showed that carbon stock potential is highly dependent on stand density, above-ground biomass, species richness and forest types. The sub-tropical forest was found to have larger carbon capacity and sequestration potential. SOC concentration and tree biomass stocks were significantly higher at the high altitude where there is less human disturbance. In general, forest coverage has increased compare to previous year in Bhutan, India and Nepal which ultimately leads to higher carbon stock potential. It is mainly due to strong policies and different strategies for conservation of forest management have reduced mass destruction despite a growing population. Despite the rules, deforestation continues to occur at various scales. However, it can be stated that the government and citizens are working hard to increase carbon stock potential, mostly through afforestation and community forest creation. In addition, it is recommended to practice sustainable forest management, regulated and planned cutting of trees and proper forest products utilization.


2007 ◽  
Vol 7 (23) ◽  
pp. 5971-5987 ◽  
Author(s):  
D. Schaub ◽  
D. Brunner ◽  
K. F. Boersma ◽  
J. Keller ◽  
D. Folini ◽  
...  

Abstract. This study evaluates NO2 vertical tropospheric column densities (VTCs) retrieved from measurements of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) above Switzerland and the Alpine region. The close correlation between pixel averaged NOx emission rates from a spatially and temporally highly resolved inventory and the NO2 VTCs under anticyclonic meteorological conditions demonstrates the general ability of SCIAMACHY to detect sources of NOx pollution in Switzerland. This correlation is further used to infer seasonal mean NOx lifetimes carefully taking into account the influence of the strong diurnal cycle in NOx emissions on these estimates. Lifetimes are estimated to 3.6 (±0.8) hours in summer and 13.1 (±3.8) hours in winter, the winter value being somewhat lower than previous estimates. A comparison between the 2003-2005 mean NO2 VTC distribution over Switzerland and the corresponding 1996–2003 mean from the Global Ozone Monitoring Experiment (GOME) illustrates the much better capability of SCIAMACHY to resolve regional scale pollution features. However, the comparison of seasonal averages over the Swiss Plateau with GOME and ground based in situ observations indicates that SCIAMACHY exhibits a too weak seasonal cycle with comparatively high values in summer and low values in winter. A problem likely contributing to the reduced values in winter (not reported in earlier literature) is the use of inaccurate satellite pixel surface pressures derived from a coarse resolution global model in the retrieval. The marked topography in the Alpine region can lead to deviations of several hundred meters between the model assumed and the real pixel-averaged surface height. A sensitivity study based on selected clear sky SCIAMACHY NO2 VTCs over the Swiss Plateau and two fixed a priori NO2 profile shapes indicates that inaccurate pixel surface pressures affect retrieved NO2 columns over complex terrain by up to 40%. For retrievals in the UV-visible spectral range with a decreasing sensitivity towards the earth's surface, this effect is of major importance when the NO2 resides close to the ground, a situation most frequently observed during winter.


2021 ◽  
Author(s):  
Liu Shuyi ◽  
Gao Bingbo

<p>Source apportionment of soil heavy metals is an challenge and urgent work as the result of the rapid development of industrialization and urbanization. The common approach is multivariate statistical analysis, such as PCA and APCS/MLR, which infers only a single pattern of sources of heavy metals in entire study area. Due to complicated pathways and processes, patterns of pollution sources in a whole region may include two or more. Hence, we developed an analytical framework based on GWPCA to explore multiple patterns of sources of soil heavy metals on a regional scale. Xiangtan county, an important grain-producing area in China, was taken as a case study, which suffers the problem of heavy metal pollutions. Our results revealed the pollution situations of five soil heavy metals(Pb, Cd, As, Cr and Hg) in farmland soils and suggested that there exists various pollution patterns of these heavy metals in Xiangtan county. In each pattern, the structure of contamination sources is different. Our study also indicates that the analytical framework considering the spatial heterogeneity of pollution sources can help take more precise practices to solve this vital problem.</p> <p> </p>


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