scholarly journals Modelle zur Biomasse- und Holzvolumenschätzung im Schweizer Gebüschwald | Modelling of biomass and wood volume in Swiss shrub forest

2011 ◽  
Vol 162 (2) ◽  
pp. 32-40 ◽  
Author(s):  
Christoph Düggelin ◽  
Meinrad Abegg

The results of the third National Forest Inventory indicate that shrub forest accounts for 5% of the total forest area in Switzerland. It grows almost exclusively in the subalpine zone and is dominated by the woody species Alnus viridis and Pinus mugo prostrata. As a consequence of global warming and the increasing demand for sustainable energy, there is a national and international interest to quantify wood volume and biomass in shrub forests. Therefore representative coppice shoots were measured in detail to establish allometric volume and biomass functions for Alnus viridis, Pinus mugo prostrata and Salix sp. For each coppice shoot the wood volume, the wet weight, the dry weight and the carbon mass was determined as a function of the base diameter. In the next step all coppice shoots of 49 sample plot areas were measured. A regression analysis shows the relationship between the degree of cover and wood volume, and hence the biomass, in a shrub forest stand. Shrub forest stands which consist of Alnus viridis and which have a degree of cover of 100% contain on average 74 m3/ha of above-ground wood volume. More than twice of that volume, namely 166 m3/ha, is contained in corresponding Pinus mugo prostrata shrub forest stands. In Swiss shrub forests, the average aboveground wood volume amounts to 66 m3/ha, corresponding to around 2 million tons of biomass. Based on the presented volume functions it will be possible to estimate the aboveground wood volume and biomass of shrub forest stands dominated by Alnus viridis and Pinus mugo prostrata with good results. Input variable is the degree of cover of the present woody species, which can be determined efficiently on aerial photography by image interpretation.

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Rahim Foroughbakhch ◽  
Artemio Carrillo Parra ◽  
Jorge Luis Hernández Piñero ◽  
Marco Antonio Alvarado Vázquez ◽  
Alejandra Rocha Estrada ◽  
...  

A research strategy was established to analyze the structure of timber trees in terms of forest productivity (volume and wood density) of 10 species. The native speciesAcacia farnesiana, Acacia schaffneri,Bumelia celastrina,Cercidium macrun,Condalia hookeri,Ebenopsis ebano,Helietta parvifolia, andProsopis laevigataand the exotic speciesEucalyptus camaldulensisandLeucaena leucocephalawere chosen due to their ecological and economic importance to the rural villages of northeastern Mexico. Measurements of different growth parameters and volume of trees were evaluated. The introduced speciesE. camaldulensisandL. leucocephalashowed the best performance in wood volume production per tree and per hectare when compared to the native species. Likewise, among the native species,E. ebano,P. laevigata,C. hookeri, andA. farnesianatended to show better characteristics in terms of wood volume production in comparison toH. parvifolia,A. schaffneri,C. macrum, andB. celastrina. Results showed a high diversity on the properties studied. The high biomass produced by most of the species considered in this study revealed their great energetic potential when used as wood and firewood or vegetal charcoal.


1992 ◽  
Vol 22 (5) ◽  
pp. 756-760 ◽  
Author(s):  
Joanne Rebbeck ◽  
Keith F. Jensen ◽  
Michael S. Greenwood

Grafted juvenile and mature scions of red spruce (Picearubens Sarg.) were grown in open-top chambers at a low-elevation site in central Maine to determine if developmental age of tissue affects response to oxidant pollution. After 18 weeks of ozone exposure, grafted red spruce showed little or no growth response to ozone. No significant ozone effect on biomass production was measured, although there were significant differences between juvenile and mature scions. At the final harvest, juvenile scion stem, stem needles, branches, branch needles, and roots had 60, 18, 74, 73, and 35% more dry weight, respectively, than mature scions. Despite the observed differences in growth and biomass production, the two graft types did not differ in their responses to ozone, suggesting that tissue age may not be a factor in ozone-tolerant woody species such as red spruce. It does not preclude the importance of assessing the influence of age on other woody species' response to air pollution. This type of information is critical for extrapolation of seedling data to field conditions with mature trees.


Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1039
Author(s):  
Andrius Kuliešis ◽  
Albertas Kasperavičius ◽  
Gintaras Kulbokas ◽  
Andrius A. Kuliešis ◽  
Aidas Pivoriūnas ◽  
...  

Background and Objectives: Significant progress in developing European national forest inventory (NFI) systems could ensure accurate evaluations of gross annual increment (GAI) and its components by employing direct measurements. However, the use of NFI data is insufficient for increasing the efficiency of forest management and the use of wood, as well as for meeting sustainable forestry needs. Specification of forest characteristics, such as GAI and its components, identification of the main factors that impact forest growth, accumulation of wood, and natural losses are among the key elements promoting the productivity of forest stands and possibilities of rational use of wood in large forest areas. The aims of this research were (a) to validate the quality of forest statistics provided by a standwise forest inventory (SFI) and (b) to reveal the potential benefits of rational wood use at the country level through the analysis of forest management results, which are based on GAI, including its components derived from the NFI. Materials and Methods: SFI and NFI data from 1998–2017 were collected from 5600 permanent sample plots and used to evaluate the main forest characteristics. Potential wood use was estimated based on the assumption that 50–70% of the total GAI is accumulated for final forest use. Results: Mean growing stock volume (GSV) is underestimated by 7–14% on average in the course of SFI. Therefore, continuous monitoring of the yield changes in forest stands, detection of factors negatively affecting yield and its accumulation, and regulation of these processes by silviculture measures could increase potential forest use in Lithuania. Conclusions: Implementation of sample-based NFI resulted in an improvement of forest characteristics and led to an increase in GSV and GAI. Continuously gathered data on GAI and its components are a prerequisite for efficient forest management and control of the use of wood.


HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 744a-744
Author(s):  
Rachel Emrick ◽  
D. L. Creech ◽  
G. Bickerstaff

This project tested rates of lignite-activated water (LAW) for its influence on seed germination, cutting propagation, and plant performance. LAW is a product of CAW Industries, Rapid City, S.D. LAW is water-activated by lignite in a process that includes the addition of sulfated castor oil, calcium chloride, magnesium sulfate, sodium meta silicate, and fossilized organics from refined lignite. LAW is reported to improve many plant performance traits. Four rates were used in this study. Seed germination trials indicated no significant differences in germination percentage with LAW applications with the two species tested, Echinacea purpurea and Hibiscus dasycalyx. In a “closed” system, LAW enhanced cutting propagation success of Aster caroliniana, Cuphea micropetala, and Verbena `Homestead Purple', as measured by percent rooting and dry weight of roots produced. Cutting propagation of two woody species, Illicium henryi and Rosa banksiae, was not improved with LAW additions. In the SFASU Arboretum, pansy performance, as measured by plant dry weight, was improved one month after establishment.


2013 ◽  
Vol 164 (4) ◽  
pp. 87-94 ◽  
Author(s):  
Barbara Huber ◽  
Monika Frehner

Expansion and development of Green Alder stands in eastern Switzerland In many subalpine regions of Switzerland, the Green Alder (Alnus viridis) is expanding as summer pastures are abandoned. The Federal Office for the Environment has set up a research project to improve the understanding of the characteristics of Green Alder and the consequences of its expansion. This project is based on a literature search, interviews with experts and GIS-based analysis of the past and present occurrence of Green Alder in three areas of eastern Switzerland. The results show that Green Alder is present at all exposures in the research areas. It is not lime-intolerant, but is less present on well drained basic subsoils. It is much more widespread than hitherto believed. In the canton of Glarus as well as in the Surselva, the area of Green Alder stands has doubled in the past 75 years. Only a few have developed to high forest stands. Therefore Green Alder stands should be considered, at least in their optimum oceanic sites, as permanent association, and not pioneer forests. In many places a broad belt of Green Alder has developed at the upper treeline, which is preventing the establishment of other species (e.g. Spruce) which might be possible because of climate change. Without intervention, the Green Alder stands will in all likelihood continue to expand over the coming decades. The areas affected by this expansion should be identified as of now, and a decision taken as to whether or not to tolerate this expansion. It is important that planning measures (agriculture, forestry, regional development) be taken early enough.


2016 ◽  
Vol 58 (1) ◽  
pp. 3-12
Author(s):  
Przemko Pachana

Abstract The purpose of the present study was to convey to the reader the method and application of the Finnish Multi-Source National Forest Inventory (MS-NFI) that was devised in the Finnish Forest Research Institute. The study area concerned is Stołowe Mountains National Park, which is located in the south-western Poland, near the border with the Czech Republic. To accomplish the above mentioned aim, the following data have been applied: timber volume derived from field sample plots, satellite image, digital map data and digital elevation model. The Pearson correlation coefficient between independent and dependent variables has been verified. Furthermore, the non-parametric k-nearest neighbours (k-NN) technique and genetic algorithm have been used in order to estimate forest stands biomass at the pixel level. The error estimates have been obtained by leave-one-out cross-validation method. The main computed forest stands features were total and mean timber volume as well as maximum and minimum biomass occurring in the examined area. In the final step, timber volume map of the growing stock has been created.


2020 ◽  
Vol 73 (1) ◽  
pp. 77-97
Author(s):  
Mait Lang ◽  
Allan Sims ◽  
Kalev Pärna ◽  
Raul Kangro ◽  
Märt Möls ◽  
...  

Abstract Since 1999, Estonia has conducted the National Forest Inventory (NFI) on the basis of sample plots. This paper presents a new module, incorporating remote-sensing feature variables from airborne laser scanning (ALS) and from multispectral satellite images, for the construction of maps of forest height, standing-wood volume, and tree species composition for the entire country. The models for sparse ALS point clouds yield coefficients of determination of 89.5–94.8% for stand height and 84.2–91.7% for wood volume. For the tree species prediction, the models yield Cohen's kappa values (taking 95% confidence intervals) of 0.69–0.72 upon comparing model results against a previous map, and values of 0.51–0.54 upon comparing model results against NFI sample plots. This paper additionally examines the influence of foliage phenology on the predictions and discusses options for further enhancement of the system.


2019 ◽  
Vol 92 (5) ◽  
pp. 577-590
Author(s):  
Hassan C David ◽  
David W MacFarlane ◽  
Sylvio Péllico Netto ◽  
Ana Paula Dalla Corte ◽  
Daniel Piotto ◽  
...  

Abstract The aim of this study was to explore methods to: (1) enhance coarse-scale estimates of wood volume from National Forest Inventories (NFIs) data and (2) map them at finer scales. The ‘standard’ coarse-scale estimation extrapolates wood volume from clusters to the grid cell they represent, using the cluster’s represented forested area (RFA) to predict the cell’s forested area. Data from a subset of Brazil’s NFI clusters were combined with Landsat-8 imagery to explore a new coarse-scale method, where forested area derived from image classification (FADIC) is used instead of RFA. The RFA- and FADIC-derived estimates of total volume were, respectively, 197.4 million m3 and 116.3 million m3. For fine-scale methods, volume was estimated and mapped at pixel level using: (i) surface reflectance-based models (SRMs), and (ii) regression-kriging (RK) and a RK model (RKM) whose inputs were latitude and longitude of pixels. The SRM-based method captured the mean and the general spatial trend of the volume well. The RK-based method also estimated the mean well, but it failed to predict higher and lower volumes. The SRM- and RK-based estimates of total volume were 211.7 million m3 and 203.3 million m3, an overestimate of 7 per cent and 3 per cent, respectively, of the ‘standard’ NFI estimate (197.4 million m3), though both estimates were within the 95 per cent confidence interval, meaning that both fine-scale methods yield total volume statistically similar to the ‘standard’ coarse-scale method.


2017 ◽  
Vol 4 (1) ◽  
pp. 160521 ◽  
Author(s):  
Friedrich J. Bohn ◽  
Andreas Huth

While various relationships between productivity and biodiversity are found in forests, the processes underlying these relationships remain unclear and theory struggles to coherently explain them. In this work, we analyse diversity–productivity relationships through an examination of forest structure (described by basal area and tree height heterogeneity). We use a new modelling approach, called ‘forest factory’, which generates various forest stands and calculates their annual productivity (above-ground wood increment). Analysing approximately 300 000 forest stands, we find that mean forest productivity does not increase with species diversity. Instead forest structure emerges as the key variable. Similar patterns can be observed by analysing 5054 forest plots of the German National Forest Inventory. Furthermore, we group the forest stands into nine forest structure classes, in which we find increasing, decreasing, invariant and even bell-shaped relationships between productivity and diversity. In addition, we introduce a new index, called optimal species distribution, which describes the ratio of realized to the maximal possible productivity (by shuffling species identities). The optimal species distribution and forest structure indices explain the obtained productivity values quite well ( R 2 between 0.7 and 0.95), whereby the influence of these attributes varies within the nine forest structure classes.


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