Comparing of allometric models of single-tree biomass intended for airborne laser sensing and terrestrial taxation of carbon pool in the forests of Eurasia

For the main tree species in North America, Europe, and Japan, a number of thousands of allometric equations for single-tree biomass estimation using mostly tree height and stem diameter at breast height are designed. An innovative airborne laser method of the forest canopy sensing allows to process online a number of morphological indices of trees, to combine them with the biomass allometric models, and to evaluate the forest carbon pools. The database of 28wood and shrub species containing 2.4 thousand of definitions is compiled for the first time in the forests of Eurasia, and on its basis the allometric transcontinental models of fractional structure of biomass of two types and dual use are developed. The first of them include as regressors the tree height and crown diameter and are intended for airborne laser location, whereas the latter have a traditional appointment for terrestrial forest biomass taxation using tree height and stem diameter. It is found that the explanatory capacity of the first model in comparison with the second one for foliage, branches, and roots is lower, but this difference is not statistically significant. The same capacity for the stem and aboveground biomass is lower too but this difference is statistically significant. Both models are designed for two different methods of taxation and cannot replace one another. Summary for Managers • We develop an innovative airborne laser method of the forest canopy sensing to evaluate the forest carbon pools. • We show this approach is highly reliable: in the most cases, there is more than 90% of tree biomass variability. • Processing speed of laser location, incommensurable with the terrestrial mensuration, gives the possibility to assess the change of carbon pool of forests on some territory during its periodic overflights. • The proposed information can be useful when implementing activities on climate stabilization, as well as in the validation of the simulation results when evaluating the carbon depositing capacity of forests. © 2018 Wiley Periodicals, Inc

Additive allometric models of single-tree biomass of Betula Sp. as a basis of regional taxation standards for Eurasia

In recent years, as the ecological role of forests has grown to a global level, the need to analyze their biological productivity in terms of biogeography has increased. Such studies are carried out mainly on a regional scale at the levels of both single-trees and forest stands. Thanks to formed by the authors the database on the biomass of 1076 sample trees of the genus Betula sp. growing on the territory of Eurasia, the trans-Eurasian model of tree biomass is proposed for the first time. The model takes into account regional differences in the biomass structure of equal-sized trees, harmonized on the principle of additivity. © 2018 Vladimir Andreevich Usoltsev et al., published by Sciendo

Geographic gradients of forest biomass of two needled pines on the territory of Eurasia

On the basis of the compiled database in a number of 3020 sample plots with determinations of forest biomass of two-needled pines (subgenus Pinus) on the territory of Eurasia from Great Britain to southern China and Japan statistically significant transcontinental gradients of stem, roots, aboveground and total biomass are established. In the direction from North to South these biomass components change according to a bell-shaped curvewith a maximum in the third (the southern temperate) zonal belt, while the biomass of needles, branches and understory is monotonically increasing within this zonal gradient from subarctic to subequato-rial zonal belts. In the direction from the Atlantic and Pacific coasts to the continentality pole in Siberia there is a biomass decrease as of all components of the wood story and the understory. The root: shoot ratio increases in the range between subarctic and southern temperate zone from 12 to 22% and then decreases to 16% in the subtropical zone, and within the southern temperate zone it monotonically increases from 20% on the oceanic coasts to 23% near continentality pole. The ratio of understory biomass to wood story biomass reduced from 4.0 to 2.5% ranging from subarctic to southern temperate zone and then rises to 3.5% in the subtropical zone, and within the south temperate zone it monotonically decreasing from the maximum value of 22% near Atlantic and Pacific coasts, approaching the level of 2-3% near the continentality pole. The results can be useful in the management of biosphere functions of forests undoubtedly. © 2018 Nicolaus Copernicus University. All rights reserved

Modeling the additive stand biomass of Larix spp. for Eurasia

When using the unique in terms of the volumes of database on the level of a stand of the genus Larix Mill., the trans-Eurasian additive allometric models of biomass for Eurasian larch forests are developed for the first time, and thereby the combined problem of model additivity and generality is solved. The additive model of forest biomass of Larix is harmonized in two levels, one of which provides the principle of additivity of biomass components, and the second one is associated with the introduction of dummy independent variables localizing model for eco-regions of Eurasia. Comparative analysis of the biomass structure of larch stands of different ecoregions at the age of 100 years shows, that the greatest values of biomass (210-450 t/ha) correspond to the regions adjacent to the Atlantic and Pacific coasts, as well as to the regions, located at the southern limit of larch growing area and the lowest – to northern taiga regions of Siberia, where larch grows on permafrost. The biomass indices of different ecoregions differed not only in absolute value but also in biomass ratios of different components; for example, the proportion of needles in the aboveground biomass is maximum (5.0-7.3%) in the northern taiga of Central Siberia and the Far East on permafrost and is minimum (1.4-1.9%) in larch forests of upper productivity having biomass values 210-450 t/ha. The proposed model and corresponding tables for estimating stand biomass makes them possible to calculate larch stand biomass on Eurasian forests when using measuring taxation

Dynamic estimation model of vegetation fractional coverage and drivers

This research reveals major changes of VFC and drivers in 2000 to 2010 in Guangdong province, China. Using MODIS NDVI, VFC directly calculated. Spatial patterns of VFC changes classified into four levels such as low (90%) in 2000, 2005 and 2010 separately. Time series of VFC showed the fitting curve is a straight line of value 0.783 (78.3%). Results showed that level >90% has highest mean of change annually, with values between 3.89% to 21.44% and level <50% has the lowest mean among all levels. The values of level 50-70% are between 7.79% and 19% and values of level 70-90% are between 68.38% and 77.25%. Trend analysis of VFC showed that in the northern mountainous regions, the economy is undeveloped and there is less human disturbance, leads to having higher VFC. In the southern coastal parts, human disturbance such as industrialization and urbanization can be seen, leads to having low VFC. Plus, using DMSP/OLS, CNLI computed. The driving factors of VFC dynamics considered human activities and climatic factors and finally Pearson correlation coefficient confirmed the relationship between VFC, climatic factors and CNLI. Result showed that VFC is positively correlated with sunshine hour, but VFC is not related to CNLI indicates that at provincial scale over research period of about 10 years, Even though urbanization and industrialization had a defined impact on the change of VFC in some cases

Additive allometric model of Quercus spp. stand biomass for Eurasia

When using the unique in terms of the volume of database on the level of stand of the genus Quercus, the trans-Eurasian additive allometric models of biomass of stands for Eurasian Quercus forests are developed for the first time, and thereby the combined problem of model additivity and generality is solved. The additive model of forest biomass of Quercus is harmonized in two ways: it eliminated the internal contradictions of the component and the total biomass equations, and in addition, it takes into account regional differences of forest stands not only on total, aboveground and underground biomass, but also on its component structure, i.e. it reflects the regional peculiarities of the component structure of biomass

Patterns for Populus spp. stand biomass in gradients of winter temperature and precipitation of Eurasia

Based on a generated database of 413 sample plots, with definitions of stand biomass of the genus Populus spp. in Eurasia, from France to Japan and southern China, statistically significant changes in the structure of forest stand biomass were found, with shifts in winter temperatures and average annual precipitation. When analyzing the reaction of the structure of the biomass of the genus Populus to temperature and precipitation in their transcontinental gradients, a clearly expressed positive relationship of all components of the biomass with the temperature in January is visible. Their relationship with precipitation is less clear; in warm climate zones, when precipitation increases, the biomass of all wood components decreases intensively, and in cold climate zones, this decrease is less pronounced. The foliage biomass does not increase when precipitation decreases, as is typical for wood components, but decreases. This can be explained by the specifics of the functioning of the assimilation apparatus, namely its transpiration activity when warming, and the corresponding increase in transpiration, which requires an increase in the influx of assimilates into the foliage, and the desiccation of the climate that reduces this influx of assimilates. Comparison of the obtained patterns with previously published results for other species from Eurasia showed partial or complete discrepancies, the causes of which require special physiological studies. The results obtained can be useful in the management of biosphere functions of forests, which is important in the implementation of climate stabilization measures, as well as in the validation of the results of simulation experiments to assess the carbon-deposition capacity of forests. © 2020 by the authors

Climatically Determined Spatial and Temporal Changes in the Biomass of Betula spp. of Eurasia in the Context of the Law of the Limiting Factor

Forest ecosystems play an essential role in climate stabilization, and the study of their capabilities in this aspect is of paramount importance. How climate changes affect the biomass of trees and stands in transcontinental gradients is unknown today? The objective of this study was (a) to verify the operation of the law of the limiting factor at the transcontinental level when modeling changes in the biomass of trees and stands of the genus Betula spp. of Eurasia in relation to geographically determined indicators of temperatures and precipitation, and (b) to show the possibility of using the constructed climate-conditioned models of tree and stand biomass in predicting temporal changes in tree and stand biomass based on the principle of space-for-Time substitution. As a result of the implementation of the principles of the limiting factor and space-for-Time substitution, a common pattern has been established on tree and stand levels: in sufficiently moisture-rich climatic zones, an increase in temperature by 1 °C with a constant amount of precipitation causes an increase in aboveground biomass, and in moisture-deficient zones, it decreases; in warm climatic zones, a decrease in precipitation by 100 mm at a constant average January temperature causes a decrease in aboveground biomass, and in cold climatic zones, it increases. © 2023 Vladimir Andreevich Usoltsev et al., published by Sciendo

The principle of space-for-time substitution in predicting Betula spp. Biomass change related to climate shifts

Human society faces problems of a global scale today, as a result of which the priorities of environmental research are shifting to the macro level, and ecology has entered the era of big data. The authors have created a database of 1,717 model trees of Betula spp. with measured indicators of diameter at breast height (DBH), tree height, age, and aboveground biomass growing in the territory of Eurasia. Regression models for aboveground biomass components are calculated, including the dendrological indices mentioned, and two climate indicators as independent variables. Based on the theory of space-for time substitution, the obtained patterns of changes in aboveground biomass in the territorial climatic gradients of Eurasia are used to predict changes in biomass due to climate shifts. In accordance with the law of the limiting factor by Liebig, it is established that in sufficiently moisture-rich climatic zones, an increase in temperature by 1??C with a constant amount of precipitation causes an increase in biomass, and in water-deficient zones ??? its decrease. In warm climatic zones, a decrease in precipitation by 100 mm at a constant average January temperature causes a decrease in biomass, and in cold climatic zones ??? its increase

A Comparative Pattern for Populus spp. and Betula spp. Stand Biomass in Eurasian Climate Gradients

Based on the generated database of 413 and 490 plots of biomass of Populus spp. and Betula spp. in Eurasia, statistically significant changes in the structure of forest stand biomass were found with shifts in January temperatures and average annual precipitation. When analyzing harvest data, the propeller-shaped biomass patterns in the gradients of average annual precipitation and average January temperatures are obtained, which are common for both deciduous species. Correspondingly, Populus and Betula forests show a regularity common to the biomass components: In the cold zones the precipitation increase leads to the increase of biomass, and in the warm ones to their decrease. In wet areas, the increase of temperature causes the decrease of biomass, and in dry areas, it causes their increase. In accordance with the law of the limiting factor by Liebig-Shelford, it is shown that both an decrease in temperature in dry conditions and a increase in precipitation in a warm climate lead to a decrease in the biomass of trees. © 2022 by the authors