Long-term effects of traditional and conservation-oriented forest management on the distribution of vertebrates in Mediterranean forests: a hierarchical hybrid modelling approach

2015 ◽  
Vol 21 (10) ◽  
pp. 1141-1154 ◽  
Author(s):  
Mirko Di Febbraro ◽  
Federica Roscioni ◽  
Ludovico Frate ◽  
Maria Laura Carranza ◽  
Lorenzo De Lisio ◽  
...  
Keyword(s):  
Forest Management ◽  
Mediterranean Forests ◽  
Long Term Effects ◽  
Hybrid Modelling ◽  
Modelling Approach

Investigation of a New Approach to Predict Water Quality Extremes with a Case Study of Chemical Determinands in Stream Water

1991 ◽  
Vol 24 (6) ◽  
pp. 25-33
Author(s):  
A. J. Jakeman ◽  
P. G. Whitehead ◽  
A. Robson ◽  
J. A. Taylor ◽  
J. Bai
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Probability Distributions ◽  
Management Strategies ◽  
Hybrid Modelling ◽  
Trend Model ◽  
Environmental Extremes ◽  
Modelling Approach

The paper illustrates analysis of the assumptions of the statistical component of a hybrid modelling approach for predicting environmental extremes. This shows how to assess the applicability of the approach to water quality problems. The analysis involves data on stream acidity from the Birkenes catchment in Norway. The modelling approach is hybrid in that it uses: (1) a deterministic or process-based description to simulate (non-stationary) long term trend values of environmental variables, and (2) probability distributions which are superimposed on the trend values to characterise the frequency of shorter term concentrations. This permits assessment of management strategies and of sensitivity to climate variables by adjusting the values of major forcing variables in the trend model. Knowledge of the variability about the trend is provided by: (a) identification of an appropriate parametric form of the probability density function (pdf) of the environmental attribute (e.g. stream acidity variables) whose extremes are of interest, and (b) estimation of pdf parameters using the output of the trend model.

scholarly journals Nachhaltiges Holzproduktionspotenzial im Schweizer Wald

2011 ◽  
Vol 162 (9) ◽  
pp. 300-311 ◽  
Author(s):  
Edgar Kaufmann
Keyword(s):  
Forest Management ◽  
Management Strategies ◽  
National Forest Inventory ◽  
Forest Area ◽  
Long Term Effects ◽  
Growing Stock ◽  
Rotation Periods ◽  
The Impact ◽  
Harvesting Costs

Potential of sustainable wood production in Swiss forests In the Swiss National Forest Inventory (NFI), the data collected in the three inventories (NFI1 1983–1985, NFI2 1993–1995, NFI3 2004–2006) provide the basis not only for analysing the present state of the forest and how it has developed up to now, but also for assessing, with the help of models, how it might develop in future. The scenario model «Massimo 3», developed at the Swiss Federal Institut for Forest, Snow and Landscape Research, is an empirical and stochastic simulation model. It relies on data from the NFI and forecasts the development of the forest according to how it is managed. Six scenarios with different management regimes were defined according to the economic, silvicultural and ecological aspects considered. In three scenarios the growing stock is kept constant at the level of NFI3, but different management strategies are used (Scenario A: basis [business as usual], Scenario E: even-aged forests are transformed into uneven-aged forests, and Scenario F: near-natural percentages of conifers are promoted). In two scenarios forest management is partially abandoned for either ecological reasons (Scenario B: reservations, 10% of the forest area is left unmanaged) or for economic reasons (Scenario C: harvesting costs, 40% of the forest area is left unmanaged). Scenario D (rotation periods are shortened) was used to study the effects of augmenting the annual harvesting amount. A forecasting time period of 100 years was selected to assess the long-term effects of the scenarios. Scenarios A, D, and E show that the sustainable harvesting potential of merchantable wood lies in a relatively narrow range of 7.1 to 7.3 million m3/year, even though in Scenario D the growing stock is reduced from 360 m3/ha to 305 m3/ha. In Scenario F regeneration is systematically established with near-natural percentages of conifers, the long-term harvesting potential is slightly less: about 6.5 million m3/year of merchantable wood. If forest management is abandoned for economic reasons on as much as 40% of the forest area (Scenario C, harvesting costs), the impact on the wood reserves is very negative.

scholarly journals Long‐term effects of antibiotic treatments on honeybee colony fitness: A modelling approach

2020 ◽  
Vol 58 (1) ◽  
pp. 70-79
Author(s):  
Laura Bulson ◽  
Matthias A. Becher ◽  
Trevelyan J. McKinley ◽  
Lena Wilfert
Keyword(s):  
Long Term Effects ◽  
Colony Fitness ◽  
Honeybee Colony ◽  
Modelling Approach

Long-term effects of forest management on nutrient cycling in spruce-fir forests

2000 ◽  
Vol 138 (1-3) ◽  
pp. 285-299 ◽  
Author(s):  
R.D Briggs ◽  
J.W Hornbeck ◽  
C.T Smith ◽  
R.C Lemin ◽  
M.L McCormack
Keyword(s):  
Forest Management ◽  
Nutrient Cycling ◽  
Long Term Effects

The relationship between forest management and amphibian ecology: a review of the North American literature

1995 ◽  
Vol 3 (3-4) ◽  
pp. 230-261 ◽  
Author(s):  
Phillip G. deMaynadier ◽  
Malcolm L. Hunter Jr.
Keyword(s):  
Forest Management ◽  
Prescribed Fire ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Forest Harvesting ◽  
Long Term Effects ◽  
Clear Cutting ◽  
Forest Practices ◽  
Logging Roads

Questions about the compatibility of forest harvesting practices and conservation of biological diversity are largely driven by concerns that habitat quality for many species may be degraded in intensively managed forest landscapes. We review the literature on relationships between common forest harvesting practices and the distribution and abundance of amphibians, a group that has attracted considerable attention in recent years because of their potential ecological importance in forest ecosystems and because of reports of widespread population declines. Clear-cut harvesting generally has negative short-term impacts on local amphibian populations, especially salamanders. An analysis of the results of 18 studies that examined the effects of clear-cutting on amphibians yielded a 3.5-fold median difference in abundance of amphibians on controls over clear-cuts. However, research on the influence of forest age suggests that the long-term effects of forest harvesting on amphibians are variable, and for many species these effects can be mitigated if regeneration practices leave adequate microhabitat structure intact. In contrast, long-term effects can be significant in forest plantations, which are often associated with intensive site preparations and stand management practices that modify levels of coarse woody debris and other microhabitats. Other forest practices reviewed for their effect on amphibians include prescribed fire, logging roads, and streamside harvesting. We discuss problems commonly encountered in the experimental design and measurement of forest amphibian populations, including a notable lack of pretreatment data, and outline several aspects of amphibian–forestry relationships in need of further research. Management recommendations relevant to conserving upland and riparian zone amphibian habitat during forest harvesting are offered.Key words: amphibians, clear-cutting, coarse woody debris, forest management, logging roads, plantations, prescribed fire, riparian, succession.

Forest management strategies that account for short-term and long-term consequences

1993 ◽  
Vol 23 (4) ◽  
pp. 563-572 ◽  
Author(s):  
Donald Ludwig
Keyword(s):  
Forest Management ◽  
Management Strategies ◽  
Forest Harvesting ◽  
Economic Returns ◽  
Long Term Effects ◽  
Short Term ◽  
Age Structured ◽  
Primary Focus ◽  
Old Trees

This paper presents a method to calculate the long-term effects of forest management decisions for an age-structured forest. The calculation of such effects is required to assess the sustainability and indeed the rationality of forest harvesting strategies. The primary focus of this paper is the issue of "falldown", i.e., the decrease in timber available for harvesting due to lack of large old trees. The largest net discounted economic returns are obtained by rapid harvesting (mining) of old growth. However, in the longer term the consequences of a decrease in harvest volume on local communities can be devastating. How can this conflict between short-term and long-term interests be reconciled? I consider a variety of strategies that vary in their sensitivity to the effects of falldown, and I present some pilot calculations that illustrate a method to weigh the consequences of following these strategies.

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