Ecoregional variations of aboveground biomass and stand structure in evergreen broadleaved forests

Abstract

Biotic and abiotic factors control aboveground biomass (AGB) and the structure of forest ecosystems. This study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam. A data set of 173 1-ha plots from 52 locations in undisturbed old-growth forests was developed. The results indicate that basal area and AGB are closely correlated with annual precipitation, but not with annual temperature, evaporation or hours of sunshine. Basal area and AGB are positively correlated with trees [ 30 cm DBH. Most areas surveyed (52.6%) in these old-growth forests had AGB of 100-200 Mg ha-1 ; 5.2% had AGB of 400-500 Mg ha-1 , and 0.6% had AGB of [ 800 Mg ha-1. Seventy percent of the areas surveyed had stand densities of 300-600 ind. ha-1 , and 64% had basal areas of 20-40 m 2 ha-1. Precipitation is an important factor influencing the AGB of old-growth, evergreen broadleaved forests in Vietnam. Disturbances causing the loss of large-diameter trees (e.g., [ 100 cm DBH) affects AGB but may not seriously affect stand density. Keywords Aboveground biomass Á Carbon storage Á Climatic variables Á Ecoregion Á Edaphic variables Á Oldgrowth forest Project funding: This word is funded by Vietnam Ministry of Science and Technology under Grant number ÐTÐL.XH.10/15, Vietnam National Foundation for Science & Technology Development (106-NN.06-2016.10), and International Foundation for Science (J-1-D-4602-3).

Tree growth, mortality and recruitment of stand dynamics over 10 years (2012-2022) in tropical forests, Phou Khao Khouay National Park, Laos

“…For instance, the current study documented a higher count of species (311 species; 135 families) compared to previous records: 145 species, 62 families [15]; 123 species, 47 families [16]; and 76 species, 42 families [17]. Across other tropical forest sites, varying species and family counts were reported: 151 species, 49 families in Vietnam [18]; 72 species [19]; 67 species [20]; 177 species, 43 families [21]. In Thailand, 306 species and 73 families were recorded [22].…”

“…[30]. Vietnam exhibited an increase in density from 522 to 557 stems/ha, BA increased from 34.4 to 42.2 m 2 /ha, and AGB increased from 298.2 to 384.2 Mg/ha [18]. India showcased a decrease in density from 1,229 to 1,032 stems/ha, BA increased from 14.6 to 14.9 m 2 /ha, and AGB increased from 3,754.53 to 3,829.51 kg/ha.…”

A Novel Method for Estimating Biomass and Carbon Sequestration in Tropical Rainforest Areas Based on Remote Sensing Imagery: A Case Study in the Kon Ha Nung Plateau, Vietnam

“…In wet tropical forests, studies have estimated that AGB is constrained by complex stand structures, high species composition diversity, and divergences between different periods of forest ecosystem development [22,35]. AGB is determined by the distribution of species, tree size and height, and the structure of each type of forest [36]. In addition, the tropical rainforest structure is also quite complex and heterogeneous, with dense canopies [37].…”