Variation in Carbon Concentration and Allometric Equations for Estimating Tree Carbon Contents of 10 Broadleaf Species in Natural Forests in Northeast China

Dong Dong,Xie Xie,Li Li,Zhang Zhang,Liu Liu

doi:10.3390/f10100928

Abstract

In this study, the effects of tree species, tissue types, and tree size on the carbon concentration were studied, and the two additive systems, one with tree diameter (D), and the other with both D and tree height (H), were developed to estimate the stem, root, branch, and foliage carbon content of 10 broadleaf species in northeast China. The coefficients of the two systems were estimated with the nonlinear seemingly unrelated regression (NSUR), while the heteroscedasticity of the model residual was solved with the weight function. Our results showed that carbon concentrations varied along with tree species and size; the tissues and foliage contained higher carbon concentration than other observed tissues. The two additive carbon equation systems exhibited good predictive and fitting performance, with Ra2 > 0.87, average prediction error of approximately 0, and small average absolute error and absolute error percentage. The carbon equation system constructed with D and H exhibited better fit and performance, particularly for the stem and total carbon. Thus, the additive carbon equation systems estimated the tree carbon of 10 broadleaf species more accurately. These carbon equations can be used to monitor the carbon pool sizes for natural forests in the Chinese National Forest Inventory.

Highlights

According to the reports from the Food and Agriculture Organization [1], forestry occupies approximately 31% of the earth’s land area, meaning it has an indispensable role in the global carbon cycle
Different carbon concentrations were detected among the tissues across all tree species
The highest carbon concentrations were in the foliage of Juglans mandshurica, Tilia amurensis, Quercus mongolica, Acer mono, Betula platyphylla, Betula davurica, and Populus davidiana; in the branches of Fraxinus mandshurica and

Summary

Introduction

According to the reports from the Food and Agriculture Organization [1], forestry occupies approximately 31% of the earth’s land area, meaning it has an indispensable role in the global carbon cycle. Almost 33.3% of the atmospheric CO2 concentration is reduced by forests, because of their carbon storage ability (approximately 2.4 Pg) and emission sequestration of CO2 (approximately 30%) [2,3]. More studies are underlining non-timber forest ecosystem services, such as natural hazards and biodiversity protection, and air and water cleaning. Temperate mixed forests are mainly located in northeastern Europe, North America, and eastern Asia. In Asia, the majority of the temperate forests are distributed in the northeastern part of China, in Heilongjiang province, which is a vital province in the climatic system and national carbon budget in China [4,5]. Among the studies on global climate change and carbon cycles, the quantity, distribution, and dynamics of forest carbon stocks are the hotspots and remain a high priority for the prediction

Methods

Results

Conclusion