national forest inventory
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Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 119
Author(s):  
Diego Rodríguez de Prado ◽  
Jose Riofrío ◽  
Jorge Aldea ◽  
Felipe Bravo ◽  
James McDermott ◽  
...  

Estimating tree height is essential for modelling and managing both pure and mixed forest stands. Although height–diameter (H–D) relationships have been traditionally fitted for pure stands, attention must be paid when analyzing this relationship behavior in stands composed of more than one species. The present context of global change makes also necessary to analyze how this relationship is influenced by climate conditions. This study tends to cope these gaps, by fitting new H–D models for 13 different Mediterranean species in mixed forest stands under different mixing proportions along an aridity gradient in Spain. Using Spanish National Forest Inventory data, a total of 14 height–diameter equations were initially fitted in order to select the best base models for each pair species-mixture. Then, the best models were expanded including species proportion by area (mi) and the De Martonne Aridity Index (M). A general trend was found for coniferous species, with taller trees for the same diameter size in pure than in mixed stands, being this trend inverse for broadleaved species. Regarding aridity influence on H–D relationships, humid conditions seem to beneficiate tree height for almost all the analyzed species and species mixtures. These results may have a relevant importance for Mediterranean coppice stands, suggesting that introducing conifers in broadleaves forests could enhance height for coppice species. However, this practice only should be carried out in places with a low probability of drought. Models presented in our study can be used to predict height both in different pure and mixed forests at different spatio-temporal scales to take better sustainable management decisions under future climate change scenarios.


2022 ◽  
Author(s):  
Tom Brandeis ◽  
Jeffery Turner ◽  
Andrés Baeza Motes ◽  
Mark Brown ◽  
Samuel Lambert

Forests ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 19
Author(s):  
Kevin M. Potter ◽  
Kurt Riitters

Genetic diversity is essential because it provides a basis for adaptation and resilience to environmental stress and change. The fundamental importance of genetic variation is recognized by its inclusion in the Montréal Process sustainability criteria and indicators for temperate and boreal forests. The indicator that focuses on forest species at risk of losing genetic variation, however, has been difficult to address in a systematic fashion. We combined two broad-scale datasets to inform this indicator for the United States: (1) tree species occurrence data from the national Forest Inventory and Analysis (FIA) plot network and (2) climatically and edaphically defined provisional seed zones, which are proxies for among-population adaptive variation. Specifically, we calculated the estimated proportion of small trees (seedlings and saplings) relative to all trees for each species and within seed zone sub-populations, with the assumption that insufficient regeneration could lead to the loss of genetic variation. The threshold between sustainable and unsustainable proportions of small trees reflected the expectation of age–class balance at the landscape scale. We found that 46 of 280 U.S. forest tree species (16.4%) may be at risk of losing genetic variation. California and the Southeast encompassed the most at-risk species. Additionally, 39 species were potentially at risk within at least half of the seed zones in which they occurred. Seed zones in California and the Southwest had the highest proportions of tree species that may be at risk. The results could help focus conservation and management activities to prevent the loss of adaptive genetic variation within tree species.


2021 ◽  
Vol 27 (2) ◽  
Author(s):  
Arta Bārdule ◽  
Guna Petaja ◽  
Aldis Butlers ◽  
Dana Purviņa ◽  
Andis Lazdiņš

Assessments of net greenhouse gas (GHG) emissions in forest land with drained organic soils conducted within the scope of National GHG inventories requires reliable data on litter production and carbon (C) input to soil information. To estimate C input through tree above-ground litter, sampling of above-ground litter was done in 36 research sites in Latvia representing typical forests with drained organic soils in hemiboreal region. To estimate C input through tree below-ground litter and litter from ground vegetation, modelling approach based on literature review and data on characteristics of forest stands with drained organic soils in Latvia provided by National Forest Inventory (NFI) was used. The study highlighted dependence of C input to soil through litter production from the stand characteristics and thus significant differences in the C input with litter between young and middle age stands. The study also proves that drained organic soils in middle age forests dominated by Silver birch, Scots pine and Norway spruce may not be the source of net GHG emissions due to offset by C input through litter production. However, there is still high uncertainty of C input with tree below-ground litter and ground vegetation, particularly, mosses, herbs and grasses which may have crucial role in C balance in forests with drained organic soils. Key words: forests, drained organic soils, litter production, carbon input, National GHG inventory


2021 ◽  
pp. 107-139
Author(s):  
Christian Temperli ◽  
Giovanni Santopuoli ◽  
Alessandra Bottero ◽  
Ignacio Barbeito ◽  
Iciar Alberdi ◽  
...  

AbstractNational Forest Inventory (NFI) data are the main source of information on forest resources at country and subcountry levels. This chapter explores the strengths and limitations of NFI-derived indicators to assess forest development with respect to adaptation to and mitigation of climate change, that is, the criteria of Climate-Smart Forestry (CSF). We reflect on harmonizing NFI-based indicators across Europe, use literature to scrutinize available indicators to evaluate CSF, and apply them in 1) Switzerland, where CSF is evaluated for NFI records and simulation model projections with four management scenarios; 2) 43 selected European countries, for which the indicators for Sustainable Forest Management (SFM) are used. The indicators were aggregated to composite indices for adaptation and mitigation and to an overall CSF rating. The Swiss NFI records showed increased CSF ratings in mountainous regions, where growing stocks increased. Simulations under business-as-usual management led to a positive CSF rating, whereas scenarios of increased harvesting decreased either only adaptation or both mitigation and adaptation. European-level results showed increases in CSF ratings for most countries. Negative adaptation ratings were mostly due to forest damages. We discuss the limitations of the indicator approach, consider the broader context of international greenhouse gas reporting, and conclude with policy recommendations.


2021 ◽  
Vol 4 ◽  
Author(s):  
Steve Prisley ◽  
Jeff Bradley ◽  
Mike Clutter ◽  
Suzy Friedman ◽  
Dick Kempka ◽  
...  

The commercial forest sector in the US includes forest landowners and forest products manufacturers, as well as numerous service providers along the supply chain. Landowners (and contractors working for them) manage forestland in part for roundwood production, and manufacturers purchase roundwood as raw material for forest products including building products, paper products, wood pellets, and others. Both types of organizations need forest resource data for applications such as strategic planning, support for certification of sustainable forestry, analysis of timber supply, and assessment of forest carbon, biodiversity, or other ecosystem services. The geographic areas of interest vary widely but typically focus upon ownership blocks or manufacturing facilities and are frequently small enough that estimates from national forest inventory data have insufficient precision. Small area estimation (SAE) has proven potential to combine field data from the national forest inventory with abundant sources of remotely sensed or other resource data to provide needed information with improved precision. Successful implementation of SAE by this sector will require cooperation and collaboration among federal and state government agencies and academic institutions and will require increased funding to improve data collection, data accessibility, and further develop and implement the needed technologies.


2021 ◽  
Vol 49 (1) ◽  
pp. 88-103
Author(s):  
Ahmet Lojo ◽  
Jusuf Musić

UDK: 630*232:582.475(497.6) It is well known that mechanical damage to trees, caused by felling and removal of timber from the forest, has multiple negative effects on the quality of the stock and the health of the forests as well as the volume increment. In Bosnia and Herzegovina there were no significant analises of volume increment loss due to bark damage of the trees. In this paper, a direct relationship between the significant damage to the bark of the stem and the size of the volume increment of individual trees was determined. Original data recorded during the Second National Forest Inventory in Bosnia and Herzegovina (2006-2009), within the accesible high economical forests was used. These forests cover a total area of 1.329.500 ha. Data on measured trees was taken from every fourth sample plot (one from cluster). 18.546 trees were selected, on which the 10-year increment of brest diameter (DBH) was measured and significant mechanical damage was recorded (LOJO et al., 2008). Of the total number of selected trees, 2.635 or 14.21% were mechanically damaged. The results of the study showed that the volume increment of trees, with significant bark damage of all tree species and thickness, was lower from 4,9% to 19,4% in average, compared to undamaged trees. Based on registered damage the bark of the stem, during second NFI BiH and determined the average losses increment on individual trees, it was estimated how much these losses are on an annual basis in, productive high forests in Bosnia and Herzegovina. The volume increment of mechanically damaged trees is statistically significantly lower compare to the increment of undamaged trees, resulting in a total loss of about 200.000 m3 / year / 1.329.500 ha.


2021 ◽  
Vol 1 ◽  
pp. 61
Author(s):  
Raphaël Aussenac ◽  
Thomas Pérot ◽  
Mathieu Fortin ◽  
Francois de Coligny ◽  
Jean-Matthieu Monnet ◽  
...  

A growing body of research suggests mixed-species stands are generally more productive than pure stands as well as less sensitive to disturbances. However, these effects of mixture depend on species assemblages and environmental conditions. Here, we present the Salem simulator, a tool that can help forest managers assess the potential benefit of shifting from pure to mixed stands from a productivity perspective. Salem predicts the dynamics of pure and mixed even-aged stands and makes it possible to simulate management operations. Its purpose is to be a decision support tool for forest managers and stakeholders as well as for policy makers. It is also designed to conduct virtual experiments and help answer research questions. In Salem, we parameterised the growth in pure stand of 12 common tree species of Europe and we assessed the effect of mixture on species growth for 24 species pairs (made up of the 12 species mentioned above). Thus, Salem makes it possible to compare the productivity of 36 different pure and mixed stands depending on environmental conditions and user-defined management strategies. Salem is essentially based on the analysis of National Forest Inventory data. A major outcome of this analysis is that we found species mixture most often increases species growth, in particular at the poorest sites. Independently from the simulator, foresters and researchers can also consider using the species-specific models that constitute Salem: the growth models including or excluding mixture effect, the bark models, the diameter distribution models, the circumference-height relationship models, as well as the volume equations for the 12 parameterised species. Salem runs on Windows, Linux, or Mac. Its user-friendly graphical user interface makes it easy to use for non-modellers. Finally, it is distributed under a LGPL license and is therefore free and open source.


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