Aboveground carbon stocks and sinks in recovering tropical forests

Abstract Background Long-term studies of community and population dynamics indicate that abrupt disturbances often catalyse changes in vegetation and carbon stocks. These disturbances include the opening of clearings, flooding, rainfall seasonality, and drought, as well as fire and direct human disturbance. Such events may be super-imposed on longer-term trends in disturbance, such as those associated with climate change (heating, drying), as well as resources. Intact neotropical forests have recently experienced increased drought frequency and fire, on top of pervasive increases in atmospheric CO2 concentrations, but we lack long-term records of responses to such changes especially in the critical transitional areas at the interface of forest and savanna biomes. Here, we present results from 20 years monitoring a valley forest (moist tropical forest outlier) in central Brazil. The forest has experienced multiple drought events and includes plots which have and which have not experienced fire. We focus on how forest structure (stem density and aboveground biomass carbon) and dynamics (stem and biomass mortality and recruitment) have responded to these disturbance regimes. ResultsOverall, the biomass carbon stock increased due to the growth of the trees already present in the forest, without any increase in the overall number of tree stems. Over time, both recruitment and especially mortality of trees tended to increase, and periods of prolonged drought in particular resulted in increased mortality rates of larger trees. This increased mortality was in turn responsible for a decline in aboveground carbon toward the end of the monitoring period. Fire in 2010, which occurred in only some of our plots, tended to exacerbate the trends of increasing mortality and losses of biomass carbon. Conclusion Prolonged droughts influence the mortality of large trees, leading to a decline in aboveground carbon stocks. Here, and in other neotropical forests, recent droughts are capable of shutting down and reversing biomass carbon sinks. These new results add to evidence that anthropogenic climate changes are already adversely impacting tropical forests.

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The impact of long dry periods on the aboveground biomass in tropical forests: 20 years of monitoring

10.21203/rs.2.22656/v2 ◽

2020 ◽

Author(s):

Milton Serpa de Meira-Junior ◽

José Roberto Rodrigues Pinto ◽

Natália Oliveira Ramos ◽

Eder Pereira Miguel ◽

Ricardo de Oliveira Gaspar ◽

...

Keyword(s):

Tropical Forests ◽

Aboveground Biomass ◽

Carbon Stocks ◽

Stem Density ◽

Biomass Carbon ◽

Neotropical Forests ◽

Aboveground Carbon ◽

Large Trees ◽

The Impact

Abstract Background Long-term studies of community and population dynamics indicate that abrupt disturbances often catalyse changes in vegetation and carbon stocks. These disturbances include the opening of clearings, flooding, rainfall seasonality, and drought, as well as fire and direct human disturbance. Such events may be super-imposed on longer-term trends in disturbance, such as those associated with climate change (heating, drying), as well as resources. Intact neotropical forests have recently experienced increased drought frequency and fire, on top of pervasive increases in atmospheric CO 2 concentrations, but we lack long-term records of responses to such changes especially in the critical transitional areas at the interface of forest and savanna biomes. Here, we present results from 20 years monitoring a valley forest (moist tropical forest outlier) in central Brazil. The forest has experienced multiple drought events and includes plots which have and which have not experienced fire. We focus on how forest structure (stem density and aboveground biomass carbon) and dynamics (stem and biomass mortality and recruitment) have responded to these disturbance regimes. Results Overall, the biomass carbon stock increased due to the growth of the trees already present in the forest, without any increase in the overall number of tree stems. Over time, both recruitment and especially mortality of trees tended to increase, and periods of prolonged drought in particular resulted in increased mortality rates of larger trees. This increased mortality was in turn responsible for a decline in aboveground carbon toward the end of the monitoring period. Fire in 2010, which occurred in only some of our plots, tended to exacerbate the trends of increasing mortality and losses of biomass carbon. Conclusion Prolonged droughts influence the mortality of large trees, leading to a decline in aboveground carbon stocks. Here, and in other neotropical forests, recent droughts are capable of shutting down and reversing biomass carbon sinks. These new results add to evidence that anthropogenic climate changes are already adversely impacting tropical forests.

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Estimating aboveground carbon density and its uncertainty in Borneo's structurally complex tropical forests using airborne laser scanning

Biogeosciences ◽

10.5194/bg-15-3811-2018 ◽

2018 ◽

Vol 15 (12) ◽

pp. 3811-3830 ◽

Cited By ~ 17

Author(s):

Tommaso Jucker ◽

Gregory P. Asner ◽

Michele Dalponte ◽

Philip G. Brodrick ◽

Christopher D. Philipson ◽

...

Keyword(s):

Tropical Forests ◽

Laser Scanning ◽

Carbon Stocks ◽

Forest Carbon ◽

Airborne Laser Scanning ◽

Tropical Asia ◽

Aboveground Carbon ◽

Airborne Laser ◽

Dipterocarp Forests ◽

The Tropics

Abstract. Borneo contains some of the world's most biodiverse and carbon-dense tropical forest, but this 750 000 km2 island has lost 62 % of its old-growth forests within the last 40 years. Efforts to protect and restore the remaining forests of Borneo hinge on recognizing the ecosystem services they provide, including their ability to store and sequester carbon. Airborne laser scanning (ALS) is a remote sensing technology that allows forest structural properties to be captured in great detail across vast geographic areas. In recent years ALS has been integrated into statewide assessments of forest carbon in Neotropical and African regions, but not yet in Asia. For this to happen new regional models need to be developed for estimating carbon stocks from ALS in tropical Asia, as the forests of this region are structurally and compositionally distinct from those found elsewhere in the tropics. By combining ALS imagery with data from 173 permanent forest plots spanning the lowland rainforests of Sabah on the island of Borneo, we develop a simple yet general model for estimating forest carbon stocks using ALS-derived canopy height and canopy cover as input metrics. An advanced feature of this new model is the propagation of uncertainty in both ALS- and ground-based data, allowing uncertainty in hectare-scale estimates of carbon stocks to be quantified robustly. We show that the model effectively captures variation in aboveground carbon stocks across extreme disturbance gradients spanning tall dipterocarp forests and heavily logged regions and clearly outperforms existing ALS-based models calibrated for the tropics, as well as currently available satellite-derived products. Our model provides a simple, generalized and effective approach for mapping forest carbon stocks in Borneo and underpins ongoing efforts to safeguard and facilitate the restoration of its unique tropical forests.

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Faculty Opinions recommendation of Invasive grass reduces aboveground carbon stocks in shrublands of the Western US.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1058717.510626 ◽

2006 ◽

Author(s):

Rowan Sage

Keyword(s):

Carbon Stocks ◽

Invasive Grass ◽

Aboveground Carbon ◽

Western Us

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Characteristics of mangrove ecosystems in Weda Bay: Environment, Vegetation, and Aboveground Carbon Stocks

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/618/1/012021 ◽

2020 ◽

Vol 618 ◽

pp. 012021

Author(s):

Suyadi

Keyword(s):

Carbon Stocks ◽

Aboveground Carbon ◽

Mangrove Ecosystems

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Sensitivity of woody carbon stocks to bark investment strategy in Neotropical savannas and forests

Biogeosciences ◽

10.5194/bg-15-233-2018 ◽

2018 ◽

Vol 15 (1) ◽

pp. 233-243 ◽

Cited By ~ 4

Author(s):

Anna T. Trugman ◽

David Medvigy ◽

William A. Hoffmann ◽

Adam F. A. Pellegrini

Keyword(s):

Fire Regime ◽

Investment Strategy ◽

Fire Frequency ◽

Carbon Stocks ◽

Plant Functional Groups ◽

High Survival ◽

Survival Strategy ◽

Aboveground Carbon ◽

Large Trees ◽

Neotropical Savannas

Abstract. Fire frequencies are changing in Neotropical savannas and forests as a result of forest fragmentation and increasing drought. Such changes in fire regime and climate are hypothesized to destabilize tropical carbon storage, but there has been little consideration of the widespread variability in tree fire tolerance strategies. To test how aboveground carbon stocks change with fire frequency and composition of plants with different fire tolerance strategies, we update the Ecosystem Demography model 2 (ED2) with (i) a fire survivorship module based on tree bark thickness (a key fire-tolerance trait across woody plants in savannas and forests), and (ii) plant functional types representative of trees in the region. With these updates, the model is better able to predict how fire frequency affects population demography and aboveground woody carbon. Simulations illustrate that the high survival rate of thick-barked, large trees reduces carbon losses with increasing fire frequency, with high investment in bark being particularly important in reducing losses in the wettest sites. Additionally, in landscapes that frequently burn, bark investment can broaden the range of climate and fire conditions under which savannas occur by reducing the range of conditions leading to either complete tree loss or complete grass loss. These results highlight that tropical vegetation dynamics depend not only on rainfall and changing fire frequencies but also on tree fire survival strategy. Further, our results indicate that fire survival strategy is fundamentally important in regulating tree size demography in ecosystems exposed to fire, which increases the preservation of aboveground carbon stocks and the coexistence of different plant functional groups.

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ABILITY OF LANDSAT-8 OLI DERIVED TEXTURE METRICS IN ESTIMATING ABOVEGROUND CARBON STOCKS OF COPPICE OAK FORESTS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xli-b8-751-2016 ◽

2016 ◽

Vol XLI-B8 ◽

pp. 751-754

Author(s):

A. Safari ◽

H. Sohrabi

Keyword(s):

Low Income ◽

Regression Models ◽

Accurate Method ◽

Carbon Stocks ◽

Low Income Countries ◽

Oak Forests ◽

Landsat 8 ◽

Zagros Mountains ◽

Aboveground Carbon ◽

Texture Metrics

The role of forests as a reservoir for carbon has prompted the need for timely and reliable estimation of aboveground carbon stocks. Since measurement of aboveground carbon stocks of forests is a destructive, costly and time-consuming activity, aerial and satellite remote sensing techniques have gained many attentions in this field. Despite the fact that using aerial data for predicting aboveground carbon stocks has been proved as a highly accurate method, there are challenges related to high acquisition costs, small area coverage, and limited availability of these data. These challenges are more critical for non-commercial forests located in low-income countries. Landsat program provides repetitive acquisition of high-resolution multispectral data, which are freely available. The aim of this study was to assess the potential of multispectral Landsat 8 Operational Land Imager (OLI) derived texture metrics in quantifying aboveground carbon stocks of coppice Oak forests in Zagros Mountains, Iran. We used four different window sizes (3×3, 5×5, 7×7, and 9×9), and four different offsets ([0,1], [1,1], [1,0], and [1,-1]) to derive nine texture metrics (angular second moment, contrast, correlation, dissimilar, entropy, homogeneity, inverse difference, mean, and variance) from four bands (blue, green, red, and infrared). Totally, 124 sample plots in two different forests were measured and carbon was calculated using species-specific allometric models. Stepwise regression analysis was applied to estimate biomass from derived metrics. Results showed that, in general, larger size of window for deriving texture metrics resulted models with better fitting parameters. In addition, the correlation of the spectral bands for deriving texture metrics in regression models was ranked as b4>b3>b2>b5. The best offset was [1,-1]. Amongst the different metrics, mean and entropy were entered in most of the regression models. Overall, different models based on derived texture metrics were able to explain about half of the variation in aboveground carbon stocks. These results demonstrated that Landsat 8 derived texture metrics can be applied for mapping aboveground carbon stocks of coppice Oak Forests in large areas.

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ESTIMATION OF ABOVEGROUND CARBON STOCK USING SAR SENTINEL-1 IMAGERY IN SAMARINDA CITY

International Journal of Remote Sensing and Earth Sciences (IJReSES) ◽

10.30536/j.ijreses.2021.v18.a3609 ◽

2021 ◽

Vol 18 (1) ◽

pp. 103

Author(s):

Bayu Elwanto Bagus Dewanto ◽

Retnadi Heru Jatmiko

Keyword(s):

Carbon Stock ◽

Open Space ◽

Exponential Model ◽

Carbon Stocks ◽

Total Carbon ◽

Empirical Modelling ◽

Aboveground Carbon ◽

Accuracy Test ◽

Estimated Error ◽

Total Carbon Stock

Estimation of aboveground carbon stock on stands vegetation, especially in green open space, has become an urgent issue in the effort to calculate, monitor, manage, and evaluate carbon stocks, especially in a massive urban area such as Samarinda City, Kalimantan Timur Province, Indonesia. The use of Sentinel-1 imagery was maximised to accommodate the weaknesses in its optical imagery, and combined with its ability to produce cloud-free imagery and minimal atmospheric influence. The study aims to test the accuracy of the estimated model of above-ground carbon stocks, to ascertain the total carbon stock, and to map the spatial distribution of carbon stocks on stands vegetation in Samarinda City. The methods used included empirical modelling of carbon stocks and statistical analysis comparing backscatter values and actual carbon stocks in the field using VV and VH polarisation. Model accuracy tests were performed using the standard error of estimate in independent accuracy test samples. The results show that Samarinda Utara subdistrict had the highest carbon stock of 3,765,255.9 tons in the VH exponential model. Total carbon stocks in the exponential VH models were 6,489,478.1 tons, with the highest maximum accuracy of 87.6 %, and an estimated error of 0.57 tons/pixel.

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