scholarly journals Modeling forest carbon cycle response to tree mortality: Effects of plant functional type and disturbance intensity

2015 ◽  
Vol 120 (11) ◽  
pp. 2178-2193 ◽  
Author(s):  
Renato Prata de Moraes Frasson ◽  
Gil Bohrer ◽  
David Medvigy ◽  
Ashley M. Matheny ◽  
Timothy H. Morin ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Tree Mortality ◽  
Forest Carbon ◽  
Plant Functional Type ◽  
Functional Type ◽  
Disturbance Intensity

scholarly journals Forest carbon sink neutralized by pervasive growth-lifespan trade-offs

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
R. J. W. Brienen ◽  
L. Caldwell ◽  
L. Duchesne ◽  
S. Voelker ◽  
J. Barichivich ◽  
...  
Keyword(s):  
Tree Growth ◽  
Tree Mortality ◽  
Carbon Sink ◽  
Growth Stimulation ◽  
Forest Carbon ◽  
System Model ◽  
Earth System ◽  
Canopy Tree ◽  
Trade Offs ◽  
Almost All

Abstract Land vegetation is currently taking up large amounts of atmospheric CO2, possibly due to tree growth stimulation. Extant models predict that this growth stimulation will continue to cause a net carbon uptake this century. However, there are indications that increased growth rates may shorten trees′ lifespan and thus recent increases in forest carbon stocks may be transient due to lagged increases in mortality. Here we show that growth-lifespan trade-offs are indeed near universal, occurring across almost all species and climates. This trade-off is directly linked to faster growth reducing tree lifespan, and not due to covariance with climate or environment. Thus, current tree growth stimulation will, inevitably, result in a lagged increase in canopy tree mortality, as is indeed widely observed, and eventually neutralise carbon gains due to growth stimulation. Results from a strongly data-based forest simulator confirm these expectations. Extant Earth system model projections of global forest carbon sink persistence are likely too optimistic, increasing the need to curb greenhouse gas emissions.

scholarly journals Evaluating and improving the Community Land Model's sensitivity to land cover

2018 ◽  
Vol 15 (15) ◽  
pp. 4731-4757 ◽  
Author(s):  
Ronny Meier ◽  
Edouard L. Davin ◽  
Quentin Lejeune ◽  
Mathias Hauser ◽  
Yan Li ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Cover ◽  
Land Surface ◽  
Soil Column ◽  
Plant Functional Type ◽  
Model Parameters ◽  
Functional Type ◽  
Land Surface Models ◽  
Surface Models ◽  
Open Land

Abstract. Modeling studies have shown the importance of biogeophysical effects of deforestation on local climate conditions but have also highlighted the lack of agreement across different models. Recently, remote-sensing observations have been used to assess the contrast in albedo, evapotranspiration (ET), and land surface temperature (LST) between forest and nearby open land on a global scale. These observations provide an unprecedented opportunity to evaluate the ability of land surface models to simulate the biogeophysical effects of forests. Here, we evaluate the representation of the difference of forest minus open land (i.e., grassland and cropland) in albedo, ET, and LST in the Community Land Model version 4.5 (CLM4.5) using various remote-sensing and in situ data sources. To extract the local sensitivity to land cover, we analyze plant functional type level output from global CLM4.5 simulations, using a model configuration that attributes a separate soil column to each plant functional type. Using the separated soil column configuration, CLM4.5 is able to realistically reproduce the biogeophysical contrast between forest and open land in terms of albedo, daily mean LST, and daily maximum LST, while the effect on daily minimum LST is not well captured by the model. Furthermore, we identify that the ET contrast between forests and open land is underestimated in CLM4.5 compared to observation-based products and even reversed in sign for some regions, even when considering uncertainties in these products. We then show that these biases can be partly alleviated by modifying several model parameters, such as the root distribution, the formulation of plant water uptake, the light limitation of photosynthesis, and the maximum rate of carboxylation. Furthermore, the ET contrast between forest and open land needs to be better constrained by observations to foster convergence amongst different land surface models on the biogeophysical effects of forests. Overall, this study demonstrates the potential of comparing subgrid model output to local observations to improve current land surface models' ability to simulate land cover change effects, which is a promising approach to reduce uncertainties in future assessments of land use impacts on climate.

scholarly journals Plant functional type mapping for earth system models

2011 ◽  
Vol 4 (3) ◽  
pp. 2081-2121 ◽  
Author(s):  
B. Poulter ◽  
P. Ciais ◽  
E. Hodson ◽  
H. Lischke ◽  
F. Maignan ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Cover ◽  
Climate Variability ◽  
Forest Cover ◽  
Plant Functional Type ◽  
Earth System ◽  
Functional Type ◽  
System Models ◽  
Satellite Sensors ◽  
Earth System Models

Abstract. The sensitivity of global carbon and water cycling to climate variability is coupled directly to land cover and the distribution of vegetation. To investigate biogeochemistry-climate interactions, earth system models require a representation of vegetation distributions that are either prescribed from remote sensing data or simulated via biogeography models. However, the abstraction of earth system state variables in models means that data products derived from remote sensing need to be post-processed for model-data assimilation. Dynamic global vegetation models (DGVM) rely on the concept of plant functional types (PFT) to group shared traits of thousands of plant species into just several classes. Available databases of observed PFT distributions must be relevant to existing satellite sensors and their derived products, and to the present day distribution of managed lands. Here, we develop four PFT datasets based on land-cover information from three satellite sensors (EOS-MODIS 1 km and 0.5 km, SPOT4-VEGETATION 1 km, and ENVISAT-MERIS 0.3 km spatial resolution) that are merged with spatially-consistent Köppen-Geiger climate zones. Using a beta (β) diversity metric to assess reclassification similarity, we find that the greatest uncertainty in PFT classifications occur most frequently between cropland and grassland categories, and in dryland systems between shrubland, grassland and forest categories because of differences in the minimum threshold required for forest cover. The biogeography-biogeochemistry DGVM, LPJmL, is used in diagnostic mode with the four PFT datasets prescribed to quantify the effect of land-cover uncertainty on climatic sensitivity of gross primary productivity (GPP) and transpiration fluxes. Our results show that land-cover uncertainty has large effects in arid regions, contributing up to 30 % (20 %) uncertainty in the sensitivity of GPP (transpiration) to precipitation. The availability of plant functional type datasets that are consistent with current satellite products and adapted for earth system models is an important component for reducing the uncertainty of terrestrial biogeochemistry to climate variability.

scholarly journals Approaches for inclusion of forest carbon cycle in life cycle assessment - a review

GCB Bioenergy ◽  
2012 ◽  
Vol 5 (5) ◽  
pp. 475-486 ◽  
Author(s):  
Tuomas Helin ◽  
Laura Sokka ◽  
Sampo Soimakallio ◽  
Kim Pingoud ◽  
Tiina Pajula
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Carbon Cycle ◽  
Forest Carbon

Aligning ecology and markets in the forest carbon cycle

2013 ◽  
Vol 11 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Matthew D Hurteau ◽  
Bruce A Hungate ◽  
George W Koch ◽  
Malcolm P North ◽  
Gordon R Smith
Keyword(s):  
Carbon Cycle ◽  
Forest Carbon

Corrigendum to “Modelling forest carbon balances considering tree mortality and removal” [Agric. For. Meteorol. 151 (2011) 179–190]

2011 ◽  
Vol 151 (5) ◽  
pp. 644 ◽  
Author(s):  
Rüdiger Grote ◽  
Ralf Kiese ◽  
Thomas Grünwald ◽  
Jean-Marc Ourcival ◽  
André Granier
Keyword(s):  
Tree Mortality ◽  
Forest Carbon ◽  
Carbon Balances

Ecosystem responses to changes in plant functional type composition: An example from the Patagonian steppe

1996 ◽  
Vol 7 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Martín R. Aguiar ◽  
José M. Paruelo ◽  
Osvaldo E. Sala ◽  
William K. Lauenroth
Keyword(s):  
Plant Functional Type ◽  
Functional Type ◽  
Ecosystem Responses ◽  
Patagonian Steppe ◽  
Type Composition
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