scholarly journals Effect of stand structure on models for volume and aboveground biomass assessment (Castelfusano pinewood, Roma)

2009 ◽  
Vol 6 (1) ◽  
pp. 75-84 ◽  
Author(s):  
A Cutini ◽  
MT Hajny ◽  
OI Gugliotta ◽  
MC Manetti ◽  
E Amorini
Keyword(s):  
Aboveground Biomass ◽  
Stand Structure ◽  
Biomass Assessment

scholarly journals Natural and Anthropogenic Variation of Stand Structure and Aboveground Biomass in Niger Delta Mangrove Forests

2021 ◽  
Vol 4 ◽  
Author(s):  
Chukwuebuka J. Nwobi ◽  
Mathew Williams
Keyword(s):  
Aboveground Biomass ◽  
Niger Delta ◽  
Stand Structure ◽  
Oil Pollution ◽  
Negative Impact ◽  
Forest Degradation ◽  
Total Biomass ◽  
Mangrove Forests ◽  
Area Index ◽  
Nipa Palm

Mangrove forests are important coastal wetlands because of the ecosystem services they provide especially their carbon potential. Mangrove forests productivity in the Niger Delta are poorly quantified and at risk of loss from oil pollution, deforestation, and invasive species. Here, we report the most extensive stem girth survey yet of mangrove plots for stand and canopy structure in the Niger Delta, across tidal and disturbance gradients. We established twenty-five geo-referenced 0.25-ha plots across two estuarine basins. We estimated aboveground biomass (AGB) from established allometric equations based on stem surveys. Leaf area index (LAI) was recorded using hemispherical photos. We estimated a mean AGB of 83.7 Mg ha–1 with an order of magnitude range, from 11 to 241 Mg ha–1. We found significantly higher plot biomass in close proximity to a protected site and tidal channels, and the lowest in the sites where urbanization and wood exploitation was actively taking place. The mean LAI was 1.45 and ranged fivefold from 0.46 to 2.41 and there was a significant positive correlation between AGB and LAI (R2 = 0.31). We divided the plots into two disturbance regimes and three nipa palm (Nypa fruticans) invasion levels. Lower stem diameter (5–15 cm) accounted for 70% of the total biomass in disturbed plots, while undisturbed regimes had a more even (∼25%) contribution of different diameter at breast height (DBH) size classes to AGB. Nipa palm invasion also showed a significant link to larger variations in LAI and the proportion of basal area removed from plots. We conclude that mangrove forest degradation and exploitation is removing larger stems (>15 cm DBH), preferentially from these mangroves forests and creates an avenue for nipa palm colonization. This research identifies opportunities to manage the utilization of mangrove resources and reduce any negative impact. Our data can be used with remote sensing to estimate biomass in the Niger Delta and the inclusion of soil, leaf properties and demographic rates can analyze mangrove-nipa competition in the region.

Stand Structure, Aboveground Biomass and Production

1999 ◽  
pp. 31-45 ◽  
Author(s):  
Joan Josep Ibàñez ◽  
María José Lledó ◽  
Juan Rafael Sánchez ◽  
Ferran Rodà
Keyword(s):  
Aboveground Biomass ◽  
Stand Structure

Aboveground biomass assessment in Colombia: A remote sensing approach

2009 ◽  
Vol 257 (4) ◽  
pp. 1237-1246 ◽  
Author(s):  
Jesús A. Anaya ◽  
Emilio Chuvieco ◽  
Alicia Palacios-Orueta
Keyword(s):  
Remote Sensing ◽  
Aboveground Biomass ◽  
Biomass Assessment

scholarly journals Temporal and Spatial Variation of Aboveground Biomass of Pinus densata and Its Drivers in Shangri-La, CHINA

2021 ◽  
Vol 19 (1) ◽  
pp. 400
Author(s):  
Dongfan Xu ◽  
Jialong Zhang ◽  
Rui Bao ◽  
Yi Liao ◽  
Dongyang Han ◽  
...  
Keyword(s):  
Population Density ◽  
Aboveground Biomass ◽  
Stand Structure ◽  
High Population ◽  
Spatial And Temporal Variation ◽  
Agricultural Activity ◽  
High Population Density ◽  
Forest Protection ◽  
Pinus Densata ◽  
River Region

Understanding the drivers of forest aboveground biomass (AGB) is essential to further understanding the forest carbon cycle. In the upper Yangtze River region, where ecosystems are incredibly fragile, the driving factors that make AGB changes differ from other regions. This study aims to investigate AGB’s spatial and temporal variation of Pinus densata in Shangri-La and decompose the direct and indirect effects of spatial attribute, climate, stand structure, and agricultural activity on AGB in Shangri-La to evaluate the degree of influence of each factor on AGB change. The continuous sample plots from National Forest Inventory (NFI) and Landsat time series were used to estimate the AGB in 1987, 1992, 1997, 2002, 2007, 2012, and 2017. The structural equation model (SEM) was used to analyze the different effects of the four factors on AGB based on five scales: entire, 1987–2002, 2007–2017, low population density, and high population density. The results are as follows: (1) The AGB of Pinus densata in Shangri-La decreased from 1987 to 2017, with the total amount falling from 9.52 million tons to 7.41 million tons, and the average AGB falling from 55.49 t/ha to 40.10 t/ha. (2) At different scales, stand structure and climate were the drivers that directly affect the AGB change. In contrast, the agricultural activity had a negative direct effect on the AGB change, and spatial attribute had a relatively small indirect effect on the AGB change. (3) Analyzing the SEM results at different scales, the change of the contribution of the agricultural activity indicates that human activity is the main negative driver of AGB change in Shangri-La, especially at the high population density region. In contrast, the change of the contribution of the stand structure and climate indicates that the loss of old trees has an important influence on the AGB change. Forest resources here and other ecologically fragile areas should be gradually restored by adhering to policies, such as strengthening forest protection, improving forest stand quality, and limiting agricultural production activities.

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