A method for the assessment of forest regrowth site index based on Earth observations and modelling

2020 ◽  
Author(s):  
Vasily Zharko ◽  
Sergey Bartalev ◽  
Mikhail Bogodukhov
Keyword(s):  
Satellite Data ◽  
Forest Type ◽  
Site Index ◽  
Forest Growth ◽  
Joint Analysis ◽  
Forest Change ◽  
Russian Science ◽  
Data Product ◽  
Forest Growth Model ◽  
Forest Regrowth

<p>Presented is a method for the estimation of a productivity class/site index of the forest regrowth after stand replacement natural and human induced disturbances. The method uses Global Forest Change project data on spatial distribution of forest loss sites (including the information about the date of the disturbance) with a 30 m resolution based on Landsat data. Joint analysis of this data resampled to 100 m spatial resolution together with a Russian Land Cover map for 2016 developed based on 100 m PROBA-V data is used to identify reforestation sites and to determine the forest type. Based on this information an appropriate forest growth model is chosen to simulate forest characteristics' dynamics for different site indexes. Finally information on forest characteristics from satellite data-based products is compared to the modeling results for the forest age, computed as a difference between the date of the disturbance and the date of the satellite data product. Reforestation site is assigned a productivity class that yields the best consistency between modeling results and existing satellite data products information.</p><p>Application of the presented method was tested over the European part of Russia using a 100 m global growing stock volume (GSV) map developed within Globbiomass project and lidar vegetation canopy height measurements from ICESat-2/ATLAS system (ATL08 data product). It was found that ICESat-2/ATLAS data is better suited for the proposed approach.</p><p>Presented method is aimed at the development of a reference dataset on forest parameters since obtained information on forest type, age and site index together can be used to estimate other crucial characteristics, including GSV, mean height, mean stem diameter, basal area, productivity, growth and mortality parameters, using the appropriate model. It is also worth mentioning that proposed approach allows estimation of characteristics of young forests which are rarely represented in the field survey-based reference datasets.</p><p>This work was supported by the Russian Science Foundation [grant number 19-77-30015]. Data processing and analysis was carried out using resources of the Centre for collective use ‘IKI-Monitoring’ developed by the Space Research Institute of the Russian Academy of Sciences.</p>

Evaluation of a mechanistic approach to mixedwood modelling

2008 ◽  
Vol 84 (2) ◽  
pp. 181-193 ◽  
Author(s):  
B. Seely ◽  
C. Hawkins ◽  
J A Blanco ◽  
C. Welham ◽  
J P Kimmins
Keyword(s):  
Species Interactions ◽  
Resource Competition ◽  
Forest Type ◽  
Forest Growth ◽  
Nutrient Competition ◽  
Forest Types ◽  
Support Tool ◽  
Management Interventions ◽  
Forest Growth Model

Mixed conifer–broadleaf forests (mixedwoods), covering more than a third of the productive forest landbase in BC, are highly valuable both as sources of fibre and as areas rich in biodiversity. In recognition of the multiple benefits of this forest type, management paradigms have transitioned from a focus on promoting conifer plantations in mixedwood areas to the management of intimate mixtures. The exceptionally dynamic growth properties and species interactions in mixedwood forests present a challenge for projecting the growth and development of different types of mixedwoods and their response to different silviculture systems. Here we evaluate the ability of a mechanistic forest growth model (FORECAST) to project patterns of stand growth and dynamics in two mixedwood forest types subjected to different silvicultural treatments. Model output is compared against field measurements from long-term silviculture trials in the Sub Boreal Spruce (SBS)—18 years, and Interior Cedar Hemlock (ICH)—10 years, biogeoclimatic zones in British Columbia, Canada. FORECAST was able to reproduce patterns of growth response in both mixedwood forest types with reasonable accuracy. An analysis of the simulated relative impact of light and nutrient competition on growth dynamics and treatment response is provided. Results suggest that competition for both light and nutrients are important factors in the dynamics of these mixedwood forest types and that long-term response data and modelling are required to adequately assess the rotation-length effects of treatments on stand development. The analysis described herein provides a level of confidence for the use of the model as a decision-support tool in these ecosystem types, but more validation work should be conducted across a range of different mixedwood forest types and management interventions as long-term datasets become available. Key words: FORECAST, mixedwood management, model testing, process-based model, resource competition

Physiologically derived predictions of Douglas-fir site index in British Columbia

2009 ◽  
Vol 85 (5) ◽  
pp. 733-744 ◽  
Author(s):  
Nicholas C Coops ◽  
Robbie A Hember
Keyword(s):  
British Columbia ◽  
Soil Water ◽  
Pseudotsuga Menziesii ◽  
Tree Height ◽  
Site Index ◽  
Douglas Fir ◽  
Forest Growth ◽  
Individual Tree ◽  
Forest Growth Model ◽  
Wide Range

Both the coastal and interior varieties of Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco; Pseudotsuga menziesii var. glauca) are found throughout a wide range of environmental conditions across British Columbia. The species is long-lived and can grow rapidly to standing volumes that approach the highest recorded among temperate conifers. Understanding the growth of the species across British Columbia, and its site index (defined as individual tree height at 50 m) is important for forest managers for both production and conservation objectives. To date, predictions of site index have traditionally been derived from forest inventory using estimates of species, height and age combined with the appropriate height–age model. More recently, process-based modelling has offered a viable alternative approach due to increased computing power, model simplifications and availability of input data. In this paper we applied a physiological forest growth model, 3-PG (Physiological Principles Predicting Growth) to predict and map site index of Douglas-fir across British Columbia at 1-km cell resolution. Our model predictions were scaled-up and compared to independent estimates of average site index for subzones from the British Columbia Biogeoclimatic Ecosystem Classification (BEC) system. Results indicated the 3-PG predictions closely matched those summarized by the BEC sub-zones (r = 0.86, p<0.001, SE = 3.0m). Predicted environmental limitations of growth suggest that the coastal variety of the species is most severely affected by temperature and frost constraints, and in some locations, soil water stress, whereas the interior variety is principally restricted by soil water availability. The proposed modelling approach complements ecological classifications and offers the potential to identify the most favourable sites for management of other native tree species under current and projected climates. Key words: Douglas-fir, site index, physiological modelling, 3-PG model, forest productivity, British Columbia, Canada

Das nachhaltig verfügbare Holznutzungspotenzial im Schweizer Wald

2016 ◽  
Vol 167 (3) ◽  
pp. 162-171 ◽  
Author(s):  
Ruedi Taverna ◽  
Michael Gautschi ◽  
Peter Hofer
Keyword(s):  
National Level ◽  
Reference Value ◽  
Forest Growth ◽  
Long Term Effects ◽  
Management Scenarios ◽  
Additional Time ◽  
Basic Scenario ◽  
Economic Framework ◽  
Forest Growth Model ◽  
New Findings

The sustainably available wood use potential in Swiss forests Based on the most recent simulations created using the Massimo forest growth model, the sustainably available wood use potential in Swiss forests was calculated for five management scenarios for the next three decades as well as for two additional time periods in the future (to monitor the long-term effects). The term “sustainably available wood use potential” covers those wood quantities that could be put on the market, taking into account socio-ecological and economic restrictions on use. The sustainably available wood use potential is provided for production regions, priority functions as well as the assortment and qualities of timber. The previously used factors of the applied “onion” model were checked and modified, if necessary, in order to take new findings and current cost developments into consideration. The calculations for all scenarios come up with a sustainably available wood use potential that is much lower than in earlier investigations. Depending on the scenario and decade, sustainably available wood use potential accounts for less than 50% of the total use potential. The biggest decrease in total use potential was due to economic framework conditions. Turning to Switzerland as a whole, towards the end of the investigation period (2106) those scenarios including a sharp increase in use in the first three decades result in a sustainably available wood use potential that is clearly lower than the reference value used at the beginning of the simulation. In the basic scenario (constant stock) and in the scenario in which the form of management used to date (increasing stock) was simulated, the sustainably available wood use potential at national level remained more or less the same throughout the simulation period, ranging from 5 to 6 million m3 per year.

scholarly journals Model-Based Estimation of Amazonian Forests Recovery Time after Drought and Fire Events

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 8
Author(s):  
Bruno L. De Faria ◽  
Gina Marano ◽  
Camille Piponiot ◽  
Carlos A. Silva ◽  
Vinícius de L. Dantas ◽  
...  
Keyword(s):  
Recovery Time ◽  
Regional Scale ◽  
Forest Growth ◽  
Forest Recovery ◽  
Fire Intensity ◽  
Natural Ecosystems ◽  
Spatial And Temporal Patterns ◽  
Southeastern Part ◽  
Forest Growth Model ◽  
Carbon Losses

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.

The EnMAP Satellite –Data Product Validation Activities

2021 ◽  
Author(s):  
Maximilian Brell ◽  
Luis Guanter ◽  
Karl Segl ◽  
Daniel Scheffler ◽  
Niklas Bohn ◽  
...  
Keyword(s):  
Satellite Data ◽  
Data Product

scholarly journals Land Cover-Specific Local Incidence Angle Correction: A Method for Time-Series Analysis of Forest Ecosystems

2021 ◽  
Vol 13 (9) ◽  
pp. 1743
Author(s):  
Daniel Paluba ◽  
Josef Laštovička ◽  
Antonios Mouratidis ◽  
Přemysl Štych
Keyword(s):  
Time Series ◽  
Land Cover ◽  
Forest Type ◽  
Incidence Angle ◽  
Correction Method ◽  
Google Earth ◽  
Forest Change ◽  
Corine Land Cover ◽  
Angle Correction ◽  
Wide Range

This study deals with a local incidence angle correction method, i.e., the land cover-specific local incidence angle correction (LC-SLIAC), based on the linear relationship between the backscatter values and the local incidence angle (LIA) for a given land cover type in the monitored area. Using the combination of CORINE Land Cover and Hansen et al.’s Global Forest Change databases, a wide range of different LIAs for a specific forest type can be generated for each scene. The algorithm was developed and tested in the cloud-based platform Google Earth Engine (GEE) using Sentinel-1 open access data, Shuttle Radar Topography Mission (SRTM) digital elevation model, and CORINE Land Cover and Hansen et al.’s Global Forest Change databases. The developed method was created primarily for time-series analyses of forests in mountainous areas. LC-SLIAC was tested in 16 study areas over several protected areas in Central Europe. The results after correction by LC-SLIAC showed a reduction of variance and range of backscatter values. Statistically significant reduction in variance (of more than 40%) was achieved in areas with LIA range >50° and LIA interquartile range (IQR) >12°, while in areas with low LIA range and LIA IQR, the decrease in variance was very low and statistically not significant. Six case studies with different LIA ranges were further analyzed in pre- and post-correction time series. Time-series after the correction showed a reduced fluctuation of backscatter values caused by different LIAs in each acquisition path. This reduction was statistically significant (with up to 95% reduction of variance) in areas with a difference in LIA greater than or equal to 27°. LC-SLIAC is freely available on GitHub and GEE, making the method accessible to the wide remote sensing community.

scholarly journals Improved understanding of drought controls on seasonal variation in Mediterranean forest canopy CO<sub>2</sub> and water fluxes through combined in situ measurements and ecosystem modelling

2009 ◽  
Vol 6 (8) ◽  
pp. 1423-1444 ◽  
Author(s):  
T. Keenan ◽  
R. García ◽  
A. D. Friend ◽  
S. Zaehle ◽  
C. Gracia ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Forest Canopy ◽  
Moisture Stress ◽  
Mediterranean Ecosystems ◽  
Forest Growth ◽  
Water Fluxes ◽  
Soil Moisture Stress ◽  
Dynamic Global Vegetation Model ◽  
Forest Growth Model

Abstract. Water stress is a defining characteristic of Mediterranean ecosystems, and is likely to become more severe in the coming decades. Simulation models are key tools for making predictions, but our current understanding of how soil moisture controls ecosystem functioning is not sufficient to adequately constrain parameterisations. Canopy-scale flux data from four forest ecosystems with Mediterranean-type climates were used in order to analyse the physiological controls on carbon and water flues through the year. Significant non-stomatal limitations on photosynthesis were detected, along with lesser changes in the conductance-assimilation relationship. New model parameterisations were derived and implemented in two contrasting modelling approaches. The effectiveness of two models, one a dynamic global vegetation model ("ORCHIDEE"), and the other a forest growth model particularly developed for Mediterranean simulations ("GOTILWA+"), was assessed and modelled canopy responses to seasonal changes in soil moisture were analysed in comparison with in situ flux measurements. In contrast to commonly held assumptions, we find that changing the ratio of conductance to assimilation under natural, seasonally-developing, soil moisture stress is not sufficient to reproduce forest canopy CO2 and water fluxes. However, accurate predictions of both CO2 and water fluxes under all soil moisture levels encountered in the field are obtained if photosynthetic capacity is assumed to vary with soil moisture. This new parameterisation has important consequences for simulated responses of carbon and water fluxes to seasonal soil moisture stress, and should greatly improve our ability to anticipate future impacts of climate changes on the functioning of ecosystems in Mediterranean-type climates.

scholarly journals Stand-Level Components of a Growth and Yield Model for Nothofagus Mixed Forests from Southern Chile

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 810
Author(s):  
Sebastian Palmas ◽  
Paulo C. Moreno ◽  
Wendel P. Cropper ◽  
Alicia Ortega ◽  
Salvador A. Gezan
Keyword(s):  
Forest Type ◽  
Geographical Area ◽  
Basal Area ◽  
Forest Growth ◽  
Model Systems ◽  
Growth And Yield ◽  
Permanent Plots ◽  
Stand Age ◽  
Yield Model ◽  
Mixed Forests

Reliable information on stand dynamics and development is needed to improve management decisions on mixed forests, and essential tools for this purpose are forest growth and yield (G&Y) models. In this study, stand-level G&Y models were built for cohorts within the natural mixed second-growth Nothofagus-dominated forests in Chile. All currently available (but limited) data, consisting of a series of stratified temporary and permanent plots established in the complete range of this forest type, were used to fit and validate these models. Linear and nonlinear models were considered, where dominant stand age, number of trees, and the proportion of basal area of Nothofagus species resulted in significant predictors to project future values of stand basal area for the different cohorts (with R2 > 0.51 for the validation datasets). Mortality was successfully modeled (R2 = 0.79), based on a small set of permanent plots, using the concept of self-thinning with a proposed model defined by the idea that, as stands get closer to a maximum density, they experience higher levels of mortality. The evaluation of these models indicated that they adequately represent the current understanding of dynamics of basal area and mortality of Nothofagus and companion species in these forests. These are the first models fitted over a large geographical area that consider the dynamics of these mixed forests. It is suggested that the proposed models should constitute the main components of future implementations of G&Y model systems.

Sign in / Sign up

Export Citation Format

Share Document