Improving tree carbon use efficiency for climate-adapted more productive forests (iCUE-Forest)

2021 ◽  
Author(s):  
Martin Thurner ◽  
Christian Beer ◽  
Stefano Manzoni ◽  
Anatoly Prokushkin ◽  
Zhiqiang Wang ◽  
...  
Keyword(s):  
Primary Production ◽  
Tree Species ◽  
Temperate Forests ◽  
Future Climate ◽  
Tree Level ◽  
Carbon Use Efficiency ◽  
N Concentration ◽  
Use Efficiency ◽  
Concentration Measurements ◽  
Plant Respiration

<p>The rate at which forests take up atmospheric CO<sub>2</sub> is critical with regard to their potential to mitigate climate change as well as their value for wood production. The allocation of carbon fixed through photosynthesis into biomass is crucially dependent on tree carbon use efficiency (CUE), which is determined by gross primary production (GPP) and plant respiration (Ra) via the relation CUE=(GPP-Ra)/GPP. The effect of future climate on CUE is unclear due to the unknown response of plant respiration to more severe increases in temperature. This motivates assessing spatial patterns in CUE across climatic gradients with marked temperature variations.  </p><p>Within the ”Improving tree carbon use efficiency for climate-adapted more productive forests” (iCUE-Forest) project, we aim to develop novel data-driven estimates of plant respiration, net primary production (NPP=GPP-Ra) and tree CUE covering the northern hemisphere boreal and temperate forests. These will be based on recent satellite-driven maps of tree living biomass, databases of N concentration measurements in tree compartments (leaves, stem/branches, roots) and the relationships between respiration rates and tissue N concentrations and temperature. Such estimates will enable the detection of spatial relationships between CUE and environmental conditions and facilitate the parameterization of dynamic global vegetation models which allow predicting the change in CUE in response to future climate and forest management.</p><p>Here we will present an extensive database of N concentration measurements in tree stems/branches and roots that we have compiled in addition to data available mainly for leaves from databases like TRY. More than 5000 measurements have been collected from the literature covering all common boreal and temperate tree species. Currently, we are exploring how the variation in tissue N concentrations is influenced by climate and tree species. Subsequently, we apply the derived tree-level relationships between tissue N concentrations and underlying drivers in combination with tree species distribution maps and estimates of tree compartment biomass based on satellite remote sensing products. In this way, we will derive novel estimates of the spatial distribution of N content in northern boreal and temperate forests that will in turn be used to assess CUE variations.</p>

Sapwood proportion and nitrogen content in boreal and temperate tree species

2020 ◽  
Author(s):  
Martin Thurner ◽  
Christian Beer ◽  
Thomas Hickler
Keyword(s):  
Tree Species ◽  
Temperate Forests ◽  
Spatial And Temporal Variation ◽  
Organic N ◽  
Tree Level ◽  
Leaf Biomass ◽  
Maintenance Respiration ◽  
Protein Repair ◽  
N Content ◽  
Plant Respiration

<p>The spatial and temporal variation in plant respiration is one of the largest unknowns in the global land carbon budget. While respiration rates are directly related to temperature, plant respiration of trees is also determined by their stem sapwood proportion, tissue nitrogen (N) contents and other factors. The sapwood proportion is related to the biomass fraction of respiring living cells in the tree stem. The respiratory costs that plants have to invest to maintain basic functions (maintenance respiration) are related to the vegetation N content, since maintenance respiration supports protein repair and replacement, and most plant organic N is in proteins.</p><p>Here we explore the variation and underlying drivers in these two plant traits (stem sapwood proportion, tissue N contents) and derive novel estimates of their spatial distribution in northern hemisphere boreal and temperate forests. For the first task, we make use of measurements of sapwood and total cross-sectional area in tree stems and of N contents per dry matter in stems, roots and leaves. Such data are collected from plant trait databases like TRY, the biomass and allometry database (BAAD) and extensive literature reviews covering the most common boreal and temperate tree species. For the second task, we apply the derived tree level relationships between these traits and the underlying drivers (species, climate, soil variables) in combination with satellite radar remote sensing based products of compartment (stem, branch, root and leaf) biomass and tree species distribution maps covering the entire northern boreal and temperate forests.</p><p>We find that both the proportion of sapwood to total stem biomass and the response of the N content to environmental conditions are fundamentally different among tree genera. For instance, the sapwood proportions are spanning from 20–30% in larch to > 70% in pine and birch forests. These findings highlight the need to consider genera-specific differences when estimating the response of plant respiration to changes in climate and forest management.</p>

scholarly journals Forest carbon use efficiency: is respiration a constant fraction of gross primary production?

2007 ◽  
Vol 13 (6) ◽  
pp. 1157-1167 ◽  
Author(s):  
EVAN H. DeLUCIA ◽  
JOHN E. DRAKE ◽  
RICHARD B. THOMAS ◽  
MIQUEL GONZALEZ-MELER
Keyword(s):  
Primary Production ◽  
Gross Primary Production ◽  
Forest Carbon ◽  
Carbon Use Efficiency ◽  
Use Efficiency

Forest thinning in ponderosa pines increases carbon use efficiency and energy flow from primary producers to primary consumers

2020 ◽  
Author(s):  
Christopher E. Doughty ◽  
Andrew J. Abraham ◽  
Tomos Prys-Jones ◽  
Tom Kolb
Keyword(s):  
Primary Production ◽  
Energy Flow ◽  
Carbon Allocation ◽  
Climate Impacts ◽  
Stem Density ◽  
Primary Producers ◽  
Forest Thinning ◽  
Carbon Use Efficiency ◽  
Use Efficiency ◽  
Primary Consumers

A better understanding of carbon use efficiency and carbon allocation during disturbance is critical to improve simulations of the global carbon cycle and understanding future climate impacts. Forest thinning of high stem density, high elevation dry western US forests is becoming more common to reduce severe fire danger but there are uncertainties about how forest thinning may impact forest carbon use efficiency, carbon allocation and energy flow through the food chain. In three, quarter ha stands with similar soils, elevation and climate along a forest thinning chronosequence near Flagstaff (AZ), we measured total net primary production (NPP of wood, fine root, and leaves), total autotrophic respiration (Ra of wood, rhizosphere, and canopy respiration), gross primary production (GPP = NPP+Ra) and large mammal herbivory (with camera traps and dung counts) over a ~2-year period. We found strong seasonality in all carbon cycling variables and herbivory, peaking during the warm, wet monsoon period. Carbon was produced more efficiently in the thinned stands, with carbon use efficiency (CUE = NPP/GPP) of ~0.50, versus the un-thinned stand with CUE of 0.34. GPP was similar in the two thinned stands ~3.5 Mg C ha-1year-1 but was about 30% greater in the un-thinned stands (5.0 Mg C ha-1 year-1). Finally, the thinned stand had higher understory NPP, large herbivore consumption and had triple the total energy going into primary consumers despite reduced total GPP. Overall, the thinning, and the return to a more natural pre-fire suppression forest structure, increased the carbon use efficiency and energy flow from primary producers to primary consumers.

scholarly journals Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy covariance, biometric and continuous soil chamber measurements

2013 ◽  
Vol 10 (5) ◽  
pp. 3089-3108 ◽  
Author(s):  
D. Zanotelli ◽  
L. Montagnani ◽  
G. Manca ◽  
M. Tagliavini
Keyword(s):  
Primary Production ◽  
Eddy Covariance ◽  
Gross Primary Production ◽  
Apple Orchard ◽  
Allocation Pattern ◽  
Carbon Use Efficiency ◽  
Standing Biomass ◽  
Measurement Protocol ◽  
Allocation Patterns ◽  
Use Efficiency

Abstract. Carbon use efficiency (CUE), the ratio of net primary production (NPP) over gross primary production (GPP), is a functional parameter that could possibly link the current increasingly accurate global GPP estimates with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, NPP and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard, both net ecosystem production and gross primary production on a yearly basis, 380 ± 30 g C m−2 and 1263 ± 189 g C m−2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruit: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.12, was higher than the previously suggested constant values of 0.47–0.50. Low nitrogen investment in fruit, the limited root apparatus, and the optimal growth temperature and nutritional condition observed at the site are suggested to be explanatory variables for the high CUE observed.

scholarly journals Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy-covariance, biometric and continuous soil chamber measurements

2012 ◽  
Vol 9 (10) ◽  
pp. 14091-14143 ◽  
Author(s):  
D. Zanotelli ◽  
L. Montagnani ◽  
G. Manca ◽  
M. Tagliavini
Keyword(s):  
Primary Production ◽  
Eddy Covariance ◽  
Gross Primary Production ◽  
Apple Orchard ◽  
Allocation Pattern ◽  
Carbon Use Efficiency ◽  
Standing Biomass ◽  
Measurement Protocol ◽  
Allocation Patterns ◽  
Use Efficiency

Abstract. Carbon use efficiency (CUE) is a functional parameter that could possibly link the current increasingly accurate global estimates of gross primary production with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, net primary production (NPP) and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a~measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross-check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard both net ecosystem production and gross primary production on yearly basis, 380 ± 30 g C m−2 and 1263 ± 189 g C m−2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruits: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.09, was higher than the previously suggested constant values of 0.47–0.50. Low nitrogen investment in fruits, the limited root-apparatus, and the optimal growth temperature and nutritional condition observed at the site are suggested to be explanatory variables for the high CUE observed.

scholarly journals Intercomparison of Terrestrial Carbon Fluxes and Carbon Use Efficiency Simulated by CMIP5 Earth System Models

2016 ◽  
Author(s):  
Dongmin Kim ◽  
Myong-In Lee ◽  
Su-Jong Jeong ◽  
Jungho Im ◽  
Dong Hyun Cha ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Primary Production ◽  
Carbon Fluxes ◽  
Earth System ◽  
Terrestrial Carbon ◽  
System Models ◽  
Carbon Use Efficiency ◽  
Terrestrial Carbon Cycle ◽  
Use Efficiency ◽  
Earth System Models

Abstract. This study compares historical simulations of the terrestrial carbon cycle produced by 10 Earth System Models (ESMs) that participated in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Using MODIS satellite estimates, this study validates the simulation of gross primary production (GPP), net primary production (NPP), and carbon use efficiency (CUE), which depend on plant function types (PFTs). The models show noticeable deficiencies compared to the MODIS data in the simulation of the spatial patterns of GPP and NPP and large differences among the simulations, although the multi-model ensemble (MME) mean provides a realistic global mean value and spatial distributions. The larger model spreads in GPP and NPP compared to those of surface temperature and precipitation suggest that the differences among simulations in terms of the terrestrial carbon cycle are largely due to uncertainties in the parameterization of terrestrial carbon fluxes by vegetation. The models also exhibit large spatial differences in their simulated CUE values and at locations where the dominant PFT changes, primarily due to differences in the parameterizations. While the MME-simulated CUE values show a strong dependence on surface temperatures, the observed CUE values from MODIS show greater complexity, as well as non-linear sensitivity. This leads to the overall underestimation of CUE using most of the PFTs incorporated into current ESMs. The results of this comparison suggest that more careful and extensive validation is needed to improve the terrestrial carbon cycle in terms of ecosystem-level processes.

scholarly journals Variabilidad de la eficiencia en el uso del carbono a partir de datos MODIS

2017 ◽  
pp. 1
Author(s):  
M. Cañizares ◽  
A. Moreno ◽  
S. Sánchez-Ruiz ◽  
M.A. Gilabert
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Vegetation Type ◽  
Gross Primary Production ◽  
Annual Average ◽  
Annual Variations ◽  
Carbon Use Efficiency ◽  
Temperature And Precipitation ◽  
Use Efficiency ◽  
Peninsular Spain

<p>Carbon use efficiency (CUE) describes how efficiently plants incorporate the carbon fixed during photosynthesis into biomass gain and can be calculated as the ratio between net primary production (NPP) and gross primary production (GPP). In this work, annual CUE has been obtained from annual GPP and NPP MODIS products for the peninsular Spain study area throughout eight years. CUE is spatially and temporally analyzed in terms of the vegetation type and annual precipitation and annual average air temperature. Results show that dense vegetation areas with moderate to high levels of precipitation present lower CUE values, whereas more arid areas present the highest CUE values. However, the temperature effect on the spatial variation of CUE is not well characterized. On the other hand, inter-annual variations of CUE of different ecosystems are discussed in terms of inter-annual variations of temperature and precipitation. It is shown that CUE exhibited a positive correlation with precipitation and a negative correlation with temperature in most ecosystems. Thus, CUE decreases when the ecosystem conditions change towards aridity.</p>

scholarly journals Global variability of carbon use efficiency in terrestrial ecosystems

2019 ◽  
Author(s):  
Xiaolu Tang ◽  
Nuno Carvalhais ◽  
Catarina Moura ◽  
Bernhard Ahrens ◽  
Sujan Koirala ◽  
...  
Keyword(s):  
Primary Production ◽  
Process Model ◽  
Net Primary Production ◽  
Gross Primary Production ◽  
Driving Factors ◽  
Spatial And Temporal Variability ◽  
Carbon Use Efficiency ◽  
Environmental Controls ◽  
C Cycle ◽  
Use Efficiency

Abstract. Vegetation carbon use efficiency (CUE) is a key measure of carbon (C) transfer from the atmosphere to terrestrial biomass, and indirectly reflects how much C is released through autotrophic respiration from the vegetation to the atmosphere. Diagnosing the variability of CUE with climate and other environmental factors is fundamental to understand its driving factors, and to further fill the current gaps in knowledge about the environmental controls on CUE. Thus, to study CUE variability and its driving factors, this study established a global database of site-year CUE based on observations from 188 field measurement sites for five ecosystem types – forest, grass, wetland, crop and tundra. The spatial pattern of CUE was predicted from global climate and soil variables using Random Forest, and compared with estimates from Dynamic Global Vegetation Models (DGVMs) from the TRENDY model ensemble. Globally, we found two prominent CUE gradients in ecosystem types and latitude, that is, CUE varied with ecosystem types, being the highest in wetlands and lowest in grassland, and CUE decreased with latitude with the lowest CUE in tropics, and the highest CUE in higher latitude regions. CUE varied greatly between data-derived CUE and TRENDY-CUE, but also among TRENDY models. Both data-derived and TRENDY-CUE challenged the constant value of 0.5 for CUE, independent of environmental controls. However, given the role of CUE in controlling the spatial and temporal variability of the terrestrial biosphere C cycle, these results emphasize the need to better understand the biotic and abiotic controls on CUE to reduce the uncertainties in prognostic land-process model simulations. Finally, this study proposed a new estimate of net primary production based on CUE and gross primary production, offering another benchmark for net primary production comparison for global carbon modelling.

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