Biomass and net primary productivity (NPP) are important factors for studying terrestrial carbon storage and the carbon cycle. Using data from existing literature, this study synthesized and analyzed a comprehensive database of direct field observations of forest biomass and NPP for Southwestern China. The biomass of mature natural forests and mature planted forests range from 81.2 Mg·ha−1 to 692.6 Mg·ha−1 (mean = 288.1 Mg·ha−1) and from 76.8 Mg·ha−1 to 670.1 Mg·ha−1 (mean = 181.5 Mg·ha−1), respectively. Mature natural forests have higher biomass than mature planted ones. The NPP values of natural and planted forests range from 1.4 Mg·ha−1·year−1 to 29.6 Mg·ha−1·year−1 (mean = 13.6 Mg·ha−1·year−1) and from 0.6 Mg·ha−1·year−1 to 26.5 Mg·ha−1·year−1 (mean = 9.9 Mg·ha−1·year−1), respectively. Correlations among biomass, NPP, and environmental factors show that NPP significantly decreases with latitude and increases with mean annual temperature, mean annual precipitation, growing degree-days on a 0 °C base, and mean annual drought index, whereas biomass positively correlates with stand age and leaf area index strongly. Karst forests exhibit almost the same NPP as non-karst forests, but the former have significantly lower biomass compared to the latter. Comprehensive regional data synthesis and analysis based on direct field observations of forest biomass and NPP are important for benchmarking global and regional vegetation and carbon models, estimating regional carbon content, restoring vegetation, and mitigating climate change.

https://www.mdpi.com/1999-4907/7/8/173/pdf

Forest Biomass and Net Primary Productivity in Southwestern China: A Meta-Analysis Focusing on Environmental Driving Factors

Observation and simulation of net primary productivity in Qilian Mountain, western China.

. The tree biomass equation, which is also called the tree allometric equation, is the most commonly used method to estimate tree and forest biomass at various spatial-temporal scales because of its high accuracy, efficiency and conciseness. For decades, many tree biomass equations have been reported in diverse types of literature (e.g., journals, books and reports). These scattered equations are being compiled, and tree biomass equation datasets are currently available for many geographical regions (e.g., Europe, North America and Sub-Saharan Africa) and countries (e.g., Australia, Indonesia and Mexico) except for in an important region of the world, Eastern Asia, specifically China. Therefore, in this study, we carried out an extensive survey and critical review of the literature (from 1978–2013) on biomass equations conducted in China and developed China’s normalized tree biomass equation dataset (ChinAllomeTree version 1.0). This dataset consists of 5,924 biomass component equations for nearly 200 species and their associated background information (e.g., geographical location, climate and stand description), showing sound geographical, climatic and forest vegetation coverages across China. The dataset is freely available at https://doi.pangaea.de/10.1594/PANGAEA.895244 for noncommercial scientific applications, which fills an important regional gap in global biomass datasets and provides key parameters for biomass estimation in forest inventory and carbon accounting in China.

/pdf/chinallometree-1-0-china-s-normalized-tree-biomass-equation-37nprznnyf.pdf

ChinAllomeTree 1.0: China's normalized tree biomass equation dataset

Biophysical limits to responses of water flux to vapor pressure deficit in seven tree species with contrasting land use regimes

http://www.cern.ac.cn/manage/ewebeditor/uploadfile/200991516351919.pdf

Estimation of the annual scavenged amount of polycyclic aromatic hydrocarbons by forests in the Pearl River Delta of Southern China

By the methods of sampling plot harvesting method and allometric dimension analysis, we measured the belowground and aboveground standing biomass and net primary productivity (NPP) of the secondary evergreen broadleaved forest in Huangmian Forest farm of Guangxi, southern China, with the location of 24 degrees 51'N and 109 degrees 51'E and an altitude of about 315 m. The total biomass was 99.96 t x hm(-2), aboveground and belowground biomasses accounted for 69.41% and 30.59%, respectively. The leaf area index of trees and undergrowth shrubs was 6.50, and the total annual NPP was 24.65 t x hm(-2) x yr(-1) by estimate, aboveground and belowground NPP accounted for 44.54% and 55.46%, respectively. The NPP of fine roots was 11.79 t x hm(-2) x yr(-1), being 86.24% of the belowground NPP.

[Biomass and net primary productivity of secondary evergreen broadleaved forest in Huangmian Forest Farm, Guangxi].

With average-tree-specific sampling method, the authors measured the root biomass of Pinus yunnanensis forests with different stand ages in Yongren County, Yunnan Province. The results indicated that total root biomass increased from 8.50 t x hm(-2) in young stand (15-17 yr) to 11.70 t x hm(-2) in middle-aged stand (30-32 yr), and to 18.91 t x hm(-2) in mature stand (60-130 yr). Among different stand age classes, the biomass of coarse roots (>10 mm) varied greatly (1.5-12.3 t x hm(-2)), whereas those of medium (5-10 mm) and fine (<5 mm) roots showed less variation (medium roots 1.4-1.6 t x hm(-2), fine roots 5.3-6.2 t x hm(-2)). The root biomass of mature stand decreased with soil depth, approximately 93% of total underground biomass being distributed in surface layer (0-30 cm), and only 7% in deeper layer (30-115 cm).

Tianxiang Luo

Papers

[Biomass and net primary productivity of secondary evergreen broadleaved forest in Huangmian Forest Farm, Guangxi].

[Root biomass of different stand-age Pinus yunnanensis forests and its distribution pattern in different soil depths].