scholarly journals The carbon sink of tropical seasonal forests in southeastern Brazil can be under threat

2020 ◽  
Vol 6 (51) ◽  
pp. eabd4548
Author(s):  
Vinícius Andrade Maia ◽  
Alisson Borges Miranda Santos ◽  
Natália de Aguiar-Campos ◽  
Cléber Rodrigo de Souza ◽  
Matheus Coutinho Freitas de Oliveira ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Carbon Sink ◽  
Global Climate ◽  
Carbon Sources ◽  
Southeastern Brazil ◽  
Forest Sites ◽  
Tropical Seasonal Forest ◽  
Terrestrial Carbon Sink ◽  
Seasonal Forests

Tropical forests have played an important role as a carbon sink over time. However, the carbon dynamics of Brazilian non-Amazon tropical forests are still not well understood. Here, we used data from 32 tropical seasonal forest sites, monitored from 1987 to 2020 (mean site monitoring length, ~15 years) to investigate their long-term trends in carbon stocks and sinks. Our results highlight a long-term decline in the net carbon sink (0.13 Mg C ha−1 year−1) caused by decreasing carbon gains (2.6% by year) and increasing carbon losses (3.4% by year). The driest and warmest sites are experiencing the most severe carbon sink decline and have already moved from carbon sinks to carbon sources. Because of the importance of the terrestrial carbon sink for the global climate, policies are needed to mitigate the emission of greenhouse gases and to restore and protect tropical seasonal forests.

scholarly journals Inventory-based estimation of aboveground net primary production in Japan's forests from 1980 to 2005

2011 ◽  
Vol 8 (8) ◽  
pp. 2099-2106 ◽  
Author(s):  
Y. Wang ◽  
J. Y. Fang ◽  
T. Kato ◽  
Z. D. Guo ◽  
B. Zhu ◽  
...  
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Carbon Sink ◽  
Field Measurements ◽  
Process Models ◽  
Aboveground Net Primary Production ◽  
Planted Forests ◽  
The Past ◽  
Terrestrial Carbon Sink

Abstract. Recent studies based on remote sensing and carbon process models have revealed that terrestrial net primary production (NPP) in the middle and high latitudes of the Northern Hemisphere has increased significantly; this is crucial for explaining the increased terrestrial carbon sink in the past several decades. Regional NPP estimation based on significant field data, however, has been rare. In this study, we estimated the long-term changes in aboveground NPP (ANPP) for Japan's forests from 1980 to 2005 using forest inventory data, direct field measurements, and an allometric method. The overall ANPP for all forest types averaged 10.5 Mg ha−1 yr−1, with a range of 9.6 to 11.5 Mg ha−1 yr−1, and ANPP for the whole country totaled 249.1 Tg yr−1 (range: 230.0 to 271.4 Tg yr−1) during the study period. Over the 25 years, the net effect of increased ANPP in needle-leaf forests and decreased ANPP in broadleaf forests has led to an increase of 1.9 Mg ha−1 yr−1 (i.e., 0.79 % yr−1). This increase may be mainly due to the establishment of plantations and the rapid early growth of these planted forests.

scholarly journals Long-term thermal sensitivity of Earth’s tropical forests

Science ◽  
2020 ◽  
Vol 368 (6493) ◽  
pp. 869-874 ◽  
Author(s):  
Martin J. P. Sullivan ◽  
Simon L. Lewis ◽  
Kofi Affum-Baffoe ◽  
Carolina Castilho ◽  
Flávia Costa ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Climate Adaptation ◽  
Global Climate ◽  
Thermal Sensitivity ◽  
Forest Carbon ◽  
Maximum Temperature ◽  
Permanent Plots ◽  
Short Term ◽  
Earth’S Climate

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate.

Long-term environmental change in tropical forests: increasing tree turnover

1996 ◽  
Vol 23 (3) ◽  
pp. 235-248 ◽  
Author(s):  
Oliver L. Phillips
Keyword(s):  
Environmental Change ◽  
Tropical Forest ◽  
Tropical Forests ◽  
Large Scale ◽  
Tree Mortality ◽  
Global Environmental Change ◽  
Atmospheric Conditions ◽  
Research Activity ◽  
Forest Sites

SummaryAnalyzing permanent plot data from 40 tropical forest sites, Phillips and Gentry (1994) found that there has been a significant tendency for tree turnover – as measured by tree mortality and recruitment – to increase since the 1950s. The dataset is now substantially improved, and includes 67 mature forest sites with turnover data representing most of the major tropical forest regions of the world. This paper presents an updated and expanded analysis of the latest data, and confirms that tree turnover has increased in mature tropical forest plots. Several artifactual explanations have been suggested but none are supported by the available data, suggesting that surviving mature tropical forests have been recently affected by large-scale anthropogenic or natural change. The effects of increased turnover may include impacts on future global atmosphere, climate, and biodiversity. Better understanding of the ecological changes in mature tropical forests depends on progress in two critical research areas – a ground-based monitoring network of long-term, fully identified tropical forest plots, and controlled manipulation of atmospheric conditions in forest experiments. Research activity in both areas needs to be substantially increased if we are to understand and predict the complex interactions between tropical forest ecology and global environmental change.

scholarly journals Inventory-based estimation of aboveground net primary production in Japan's forests from 1980 to 2005

2011 ◽  
Vol 8 (1) ◽  
pp. 1463-1481 ◽  
Author(s):  
Y. Wang ◽  
J. Y. Fang ◽  
T. Kato ◽  
Z. D. Guo ◽  
B. Zhu ◽  
...  
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Carbon Sink ◽  
Field Measurements ◽  
Process Models ◽  
Aboveground Net Primary Production ◽  
Planted Forests ◽  
The Past ◽  
Terrestrial Carbon Sink

Abstract. Recent studies based on remote sensing and carbon process models have revealed that terrestrial net primary production (NPP) in the middle and high latitudes of the Northern Hemisphere has increased significantly; this is crucial for explaining the increased terrestrial carbon sink in the past several decades. Regional NPP estimation based on significant field data, however, has been rare. In this study, we estimated the long-term changes in aboveground NPP (ANPP) for Japan's forests from 1980 to 2005, using forest inventory data, direct field measurements, and an allometric method. The overall ANPP for all forest types averaged 10.5 Mg ha−1 yr−1, with a range of 9.6 to 11.5 Mg ha−1 yr−1, and ANPP for the whole country totaled 249.1 Tg yr−1 (range: 230.0 to 271.4 Tg yr−1) during the study period. Over the 25 years, the net effect of increased ANPP in needle-leaf forests and decreased ANPP in broadleaf forests has led to an increase of 1.9 Mg ha−1 yr−1 (i.e., 0.79% yr−1). This increase may be mainly due to the establishment of plantations and the rapid early growth of these planted forests.

scholarly journals Resistance of African tropical forests to an extreme climate anomaly

2021 ◽  
Vol 118 (21) ◽  
pp. e2003169118
Author(s):  
Amy C. Bennett ◽  
Greta C. Dargie ◽  
Aida Cuni-Sanchez ◽  
John Tshibamba Mukendi ◽  
Wannes Hubau ◽  
...  
Keyword(s):  
Tropical Forests ◽  
El Niño ◽  
Tree Mortality ◽  
El Nino ◽  
Southern Oscillation ◽  
Carbon Sink ◽  
El Niño Event ◽  
Dry Conditions ◽  
Carbon Losses

The responses of tropical forests to environmental change are critical uncertainties in predicting the future impacts of climate change. The positive phase of the 2015–2016 El Niño Southern Oscillation resulted in unprecedented heat and low precipitation in the tropics with substantial impacts on the global carbon cycle. The role of African tropical forests is uncertain as their responses to short-term drought and temperature anomalies have yet to be determined using on-the-ground measurements. African tropical forests may be particularly sensitive because they exist in relatively dry conditions compared with Amazonian or Asian forests, or they may be more resistant because of an abundance of drought-adapted species. Here, we report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON). We use 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015–2016 El Niño event. These plots experienced the highest temperatures and driest conditions on record. The record temperature did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality, but the record drought did significantly decrease net carbon uptake. Overall, the long-term biomass increase of these forests was reduced due to the El Niño event, but these plots remained a live biomass carbon sink (0.51 ± 0.40 Mg C ha−1 y−1) despite extreme environmental conditions. Our analyses, while limited to African tropical forests, suggest they may be more resistant to climatic extremes than Amazonian and Asian forests.

Projecting long-term soil organic dynamics in Australia's rangelands

2021 ◽  
Author(s):  
Mingxi Zhang ◽  
Raphael Viscarra Rossel
Keyword(s):  
Short Term Memory ◽  
Carbon Sink ◽  
Soil C ◽  
Tropical Regions ◽  
Explanatory Variables ◽  
The North ◽  
Terrestrial Carbon Sink ◽  
Organic Carbon Stock ◽  
Trees And Shrubs

<p>Rangelands in Australia are vast and occupy more than 80% of the continental land area. They extend across arid, semi-arid, and the tropical regions with seasonal, variable rainfall in the north. They include diverse, relatively undisturbed grasslands, shrublands, woodlands and tropical savanna ecosystems. They represent Australia’s largest terrestrial carbon sink as they account for almost 70% of Australia's total soil organic carbon stock (Viscarra Rossel et al., 2014), more than all above-ground sources of carbon (native grasses, trees and shrubs) in these regions (Gifford et al., 1992). Here we have developed a novel space-time approach for projecting the long-term C dynamics of rangelands soils using Long Short-Term Memory (LSTM) deep learning neural networks. We further demonstrate how the networks might be interpreted and quantified the influence of explanatory variables on the spatiotemporal dynamics of soil C in these regions. Our results provide an improved ability to accurately model long-term carbon dynamics, which is needed to confidently predict changes in soil C from change in climate or anthropogenic disturbance. The information is critical for improving our understanding of soil C in these regions and for understanding the potential for sequestering C in the rangelands.</p>

Emergent constraints on global carbon-climate feedbacks from regional atmospheric aridity

2020 ◽  
Author(s):  
Armineh Barkhordarian ◽  
Kevin W. Bowman ◽  
Noel Cressie ◽  
Jeffrey Jewell ◽  
Johanna Baehr
Keyword(s):  
Carbon Sink ◽  
Earth System ◽  
Climate Feedbacks ◽  
Terrestrial Carbon ◽  
Terrestrial Carbon Sequestration ◽  
Interannual Fluctuations ◽  
Terrestrial Carbon Sink ◽  
Emergent Constraint ◽  
Global Carbon

<p>The vulnerability of terrestrial carbon sequestration to increases in fossil fuel emissions is one of the most important feedbacks in the Earth System.  However, the relative importance of temperature and moisture controls on regional terrestrial CO2 fluxes varies substantially and yet critical to unraveling their roles in carbon-climate feedbacks. Here, we employ the Hierarchical Emergent Constraint (HEC) to quantify an emergent relationship between spatially- explicit sensitivities of carbon fluxes to atmospheric aridity across an ensemble of Earth System Models (ESMs) and the long-term sensitivity of tropical land-carbon storage to atmospheric aridity.  Our results show that interannual fluctuations in atmospheric aridity, as an important driver of atmospheric water demand for plants, substantially impact the terrestrial carbon sink. However, this analysis, which is conditioned on observations, leads to a substantially lower feedback than predicted by ESMs alone. Furthermore, we show that a relatively small number of regions have an out-sized impact on global carbon climate-feedbacks.  These findings underscore the role of both water and temperature on carbon-climate feedbacks while the regional attribution provided by HEC points to areas for further process-based research.</p>

scholarly journals Cenozoic carbonate burial along continental margins

Geology ◽  
2019 ◽  
Vol 47 (11) ◽  
pp. 1025-1028 ◽  
Author(s):  
Robin van der Ploeg ◽  
Bernard P. Boudreau ◽  
Jack J. Middelburg ◽  
Appy Sluijs
Keyword(s):  
Sea Level ◽  
Middle Miocene ◽  
Carbon Sink ◽  
Global Climate ◽  
Continental Margins ◽  
Marine Carbonate ◽  
Major Increase ◽  
Continental Weathering ◽  
Climate Transition

Abstract Marine carbonate burial represents the largest long-term carbon sink at Earth’s surface, occurring in both deep-sea (pelagic) environments and shallower waters along continental margins. The distribution of carbonate accumulation has varied over geological history and impacts the carbon cycle and ocean chemistry, but it remains difficult to quantitatively constrain. Here, we reconstruct Cenozoic carbonate burial along continental margins using a mass balance for global carbonate alkalinity, which integrates independent estimates for continental weathering and pelagic carbonate burial. Our results indicate that major changes in marginal carbonate burial were associated with important climate and sea-level change events, including the Eocene-Oligocene transition (ca. 34 Ma), the Oligocene-Miocene boundary Mi-1 glaciation (ca. 23 Ma), and the middle Miocene climate transition (ca. 14 Ma). In addition, we find that a major increase in continental weathering from ca. 10 Ma to the present may have driven a concomitant increase in pelagic carbonate burial. Together, our results show that changes in global climate, sea level, and continental weathering have all impacted carbonate burial over the Cenozoic, but the relative importance of these processes may have varied through time.

Die Kohlenstoff-Senkenkapazität des Schweizer Waldes | Carbon sink capacity of Swiss forests

2008 ◽  
Vol 159 (9) ◽  
pp. 273-280
Author(s):  
Annett Wolf
Keyword(s):  
Large Scale ◽  
Carbon Sink ◽  
Carbon Sources ◽  
Growth Potential ◽  
Carbon Uptake ◽  
Sink Strength ◽  
Sink Capacity ◽  
Climate Influences ◽  
Management Changes

To assess the carbon sink capacity of Swiss forests, we summarize what is known about the carbon content of Swiss forests today, considering carbon stored in the trees as well as in soils. We explain briefly how climate influences carbon uptake and carbon emissions from forest ecosystems. Finally, we analyze simulation studies, which investigate the future development of carbon pools and fluxes in Swiss forests. We found that carbon stocks in Swiss forests are already high today, hence the growth potential that would lead to further carbon uptake is comparatively small. Still, within the next decades Swiss forests are likely to act as carbon sinks as long as management does not change dramatically. The afforestation of abandoned land and the change in treeline will be mainly responsible for the additional uptake of carbon. In the next decades, management decisions will influence the sink strength of Swiss forests more than climatic changes. In the long term, the sink capacity of forests is likely to decrease and in case of drastic climatic or management changes, the forests can even become large-scale carbon sources.

Sign in / Sign up

Export Citation Format

Share Document