Magnitude, distribution and causes of terrestrial carbon sinks and some implications for policy

2002 ◽  
Vol 2 (1) ◽  
pp. 71-88 ◽  
Author(s):  
R. A. Houghton
Keyword(s):  
Carbon Sinks ◽  
Terrestrial Carbon ◽  
Magnitude Distribution

Does forest growth acceleration lead to denser stands? Insights from Swiss forests and mechanistic modelling

2021 ◽  
Author(s):  
Laura Marques ◽  
Ensheng Weng ◽  
Harald Bugmann ◽  
David I. Forrester ◽  
Martina Hobi ◽  
...  
Keyword(s):  
Tree Growth ◽  
Carbon Balance ◽  
Tree Mortality ◽  
Forest Growth ◽  
Growth Enhancement ◽  
Carbon Sinks ◽  
Terrestrial Carbon ◽  
Model Simulations ◽  
Leaf Level ◽  
Use Efficiency

<p>Forest demographic processes - growth, recruitment and mortality - are being altered by global change. The changing balance between growth and mortality strongly influences forest dynamics and the carbon balance. Elevated atmospheric carbon dioxide (eCO<sub>2</sub>) has been reported to enhance photosynthesis and tree growth rates by increasing both light-use efficiency (LUE) and water-use efficiency (WUE). Tree growth enhancement could be translated into an increase in biomass stocks or could be associated with a reduction in the longevity of trees, thus reducing the ability of forest ecosystems to act as carbon sinks over long timescales. These links between growth and mortality, and the implications for forest stand density and self-thinning relationships are still debated. Scarce empirical evidence exists for how changing drivers affect tree mortality due to existing data and modelling limitations. Understanding the causes of observed mortality trends and the mechanisms underlying these processes is critical for accurate projections of global terrestrial carbon storage and its feedbacks to anthropogenic climate change.</p><p>Here, we combine a mechanistic model with empirical forest data to better understand the causes of changes in tree mortality and the implications for past and future trends in forest tree density. Specifically, we test the Grow-Fast-Die-Young hypothesis to investigate if a leaf-level CO<sub>2</sub> fertilization effect may lead to an increase in the biomass stock in forest stands. We use a novel vegetation demography model (LM3-PPA) which includes vegetation dynamics with biogeochemical processes allowing for explicit representation of individuals and a mechanistic treatment of tree mortality. The key links between leaf-level assimilation and stand dynamics depend on the carbon turnover time. In this sense, we investigate alternative mortality assumptions about the functional dependence of mortality on tree size, tree carbon balance or growth rate. These formulations represent typical approaches to simulate mortality in mechanistic forest models. Model simulations show that increasing photosynthetic LUE leads to higher biomass stocks, with contrasting behavior among mortality assumptions. Empirical data from Swiss forest inventories support the results from the model simulations showing a shift upwards in the self-thinning relationships, with denser stands and bigger trees. This data-supported mortality-modelling helps to identify links between forest responses and environmental changes at the leaf, tree and stand levels and yields new insight into the causes of currently observed terrestrial carbon sinks and future responses.</p>

Land Use and Terrestrial Carbon Sinks

2003 ◽  
pp. 111-136 ◽  
Author(s):  
A. J. Dolman ◽  
G. J. Nabuurs ◽  
P. K. Kuikman ◽  
R. W. A. Hutjes ◽  
J. Huygen ◽  
...  
Keyword(s):  
Land Use ◽  
Carbon Sinks ◽  
Terrestrial Carbon

scholarly journals Interactive Impacts of Fire and Vegetation Dynamics on Global Carbon and Water Budgets using Community Land Model version 4.5

2018 ◽  
Author(s):  
Hocheol Seo ◽  
Yeonjoo Kim
Keyword(s):  
Land Surface ◽  
Vegetation Dynamics ◽  
Carbon Sink ◽  
Vegetation Type ◽  
Water Fluxes ◽  
Carbon Sinks ◽  
Terrestrial Carbon ◽  
Moisture Profile ◽  
Community Land Model ◽  
Model Version

Abstract. Fire plays an important role in terrestrial ecosystems. The burning of biomass affects carbon and water fluxes and the distribution of vegetation. To understand the effect of the interactive processes of fire and ecological succession on land surface carbon and water fluxes, this study utilized the Community Land Model version 4.5 to conduct a series of experiments that included and excluded fire and dynamic vegetation processes. Results of the experiments that excluded dynamic vegetation showed a global increase in net ecosystem production (NEP) in post-fire regions, which has been shown in previous studies with the similar modeling practices. However, inclusion of dynamic vegetation revealed a fire-induced decrease in NEP in some regions. Additionally, the carbon sink in post-fire regions reduced when the dominant vegetation type was changed from trees to grasses. This study shows that inclusion of dynamic vegetation enhances carbon emissions from fire by reducing terrestrial carbon sinks; however, this effect is somewhat mitigated by the increase in terrestrial carbon sinks when dynamic vegetation is not used. Results also show that fire-induced changes in vegetation modify the soil moisture profile because grasslands are more dominant in post-fire regions; this results in less moisture within top soil layers compared to non-burned regions, even though transpiration is reduced overall. These findings are different from those of previous fire model evaluations, that ignore vegetation dynamics, and thus highlight the importance of interactive processes between fire and vegetation dynamics, particularly when evaluating recent model developments with respect to fire and vegetation dynamics.

Quantifying Terrestrial Carbon Sinks

2004 ◽  
Vol 67 (2-3) ◽  
pp. 145-146 ◽  
Author(s):  
Keyword(s):  
Carbon Sinks ◽  
Terrestrial Carbon

Identifying terrestrial carbon sinks: Classification of successional stages in regenerating tropical forest from Landsat TM data

1996 ◽  
Vol 55 (3) ◽  
pp. 205-216 ◽  
Author(s):  
Giles M. Foody ◽  
Gintautas Palubinskas ◽  
Richard M. Lucas ◽  
Paul J. Curran ◽  
Miroslav Honzak
Keyword(s):  
Tropical Forest ◽  
Landsat Tm ◽  
Carbon Sinks ◽  
Terrestrial Carbon ◽  
Successional Stages
Sign in / Sign up

Export Citation Format

Share Document