Estimating net primary production of forests in the Canadian Prairie Provinces using an inventory-based carbon budget model

2002 ◽  
Vol 32 (1) ◽  
pp. 161-169 ◽  
Author(s):  
Zhong Li ◽  
Michael J Apps ◽  
E Banfield ◽  
Werner A Kurz
Keyword(s):  
Primary Production ◽  
Carbon Budget ◽  
Fine Root ◽  
Net Primary Production ◽  
Root Turnover ◽  
Stand Age ◽  
Parameter Estimates ◽  
Budget Model ◽  
Carbon Budget Model ◽  
Prairie Provinces

The Carbon Budget Model of the Canadian Forest Sector (CBM-CFS2) is a forest inventory-based ecosystem simulation model. It has been used previously for both retrospective and projective analyses of the carbon pools and fluxes of the Canadian forest ecosystems at the national, regional, and stand level. The objective of this study was to determine and evaluate forest net primary production (NPP) in the three Prairie Provinces in west-central Canada, as estimated by the model. The model simulated an averaged aboveground NPP (NPPA) of 172 g C·m–2·year–1 for the regional forests, varying from 72 to 293 g C·m–2·year–1, depending on ecoclimatic province, forest type, age, and site productivity. Comparisons of NPPA estimates for the boreal forest (165–179 g C·m–2·year–1) with results from direct measurements, modeling, and empirical calculations show that the CBM-CFS2 produced reasonable estimates of NPPA. The model incorporates different types of disturbances such as wildfire, harvesting, and insects and is able to evaluate NPP changes with stand age. However, belowground NPP may be overestimated, especially for young and unproductive stands. This can be explained by the current parameter estimates for the fine-root component of belowground biomass and for fine-root turnover rates.

Belowground biomass dynamics in the Carbon Budget Model of the Canadian Forest Sector: recent improvements and implications for the estimation of NPP and NEP

2003 ◽  
Vol 33 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Zhong Li ◽  
Werner A Kurz ◽  
Michael J Apps ◽  
Sarah J Beukema
Keyword(s):  
Primary Production ◽  
Root Biomass ◽  
Carbon Budget ◽  
Fine Root ◽  
Net Primary Production ◽  
Fine Root Biomass ◽  
Forest Sector ◽  
Regression Equations ◽  
Budget Model ◽  
Carbon Budget Model

In the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS2), root biomass and dynamics are estimated using regression equations based on the literature. A recent analysis showed that some of these equations might overestimate belowground net primary production (NPPB). The objectives of this study were to update the compilation of root biomass and turnover data, to recalculate the regression equations and to evaluate the impact of the new equations on CBM-CFS2 estimates of net primary production (NPP) and net ecosystem production (NEP). We updated all equations based on 635 pairs of aboveground and belowground data compiled from published studies in the cold temperate and boreal forests. The new parameter for the equation to predict total root biomass for softwood species changed only slightly, but the changes for hardwood species were statistically significant. A new equation form, which improved the accuracy and biological interpretation, was used to predict fine root biomass as a proportion of total root biomass. The annual rate of fine root turnover was currently estimated to be 0.641 of fine root biomass. A comparison of NPP estimates from CBM-CFS2 with results from field measurements, empirical calculations and modeling indicated that the new root equations predicted reasonable NPPB values. The changes to the root equations had little effect on NEP estimates.

Estimation of root biomass and dynamics for the carbon budget model of the Canadian forest sector

1996 ◽  
Vol 26 (11) ◽  
pp. 1973-1979 ◽  
Author(s):  
Werner A. Kurz ◽  
Sarah J. Beukema ◽  
Michael J. Apps
Keyword(s):  
Aboveground Biomass ◽  
Root Biomass ◽  
Regression Models ◽  
Carbon Budget ◽  
Fine Root ◽  
Root Production ◽  
Forest Sector ◽  
Budget Model ◽  
Carbon Budget Model ◽  
Hardwood Species

Root biomass is expected to contribute significantly to total ecosystem carbon (C) pools and their dynamics. A method for estimating belowground biomass pools and their dynamics was developed for application in the carbon budget model of the Canadian forest sector (CBM-CFS2). Root biomass data for temperate and boreal softwood and hardwood species were compiled from the literature. Total root biomass for softwood and hardwood species was estimated using regression models that incorporate total aboveground biomass as the independent variable. Fine root biomass was estimated as a proportion of total root biomass using a single regression model for softwood and hardwood species combined. A regression model to estimate annual fine root production was derived for softwood and hardwood species. In the CBM-CFS2, net increments of total biomass were estimated using empirical growth functions to predict aboveground biomass. The regression models developed in this study were then used to predict the corresponding root biomass. Total root production was calculated as the sum of net increments, i.e., the change in root biomass per hectare plus annual turnover. The application of this approach to estimate root biomass pools and their dynamics in the CBM-CFS2 is demonstrated. As with all regression models that are developed from regional databases, this approach should not be used to predict root biomass and dynamics of an individual forest ecosystem, because the influence of species, site, and stand characteristics may lead to significant deviations from the regional averages.

scholarly journals Reviews and syntheses: Hidden forests, the role of vegetated coastal habitats in the ocean carbon budget

2017 ◽  
Vol 14 (2) ◽  
pp. 301-310 ◽  
Author(s):  
Carlos M. Duarte
Keyword(s):  
Carbon Sequestration ◽  
Organic Carbon ◽  
Primary Production ◽  
Deep Sea ◽  
Carbon Budget ◽  
Net Primary Production ◽  
Global Ocean ◽  
Coastal Habitats ◽  
Global Carbon Budget ◽  
Global Carbon

Abstract. Vegetated coastal habitats, including seagrass and macroalgal beds, mangrove forests and salt marshes, form highly productive ecosystems, but their contribution to the global carbon budget remains overlooked, and these forests remain hidden in representations of the global carbon budget. Despite being confined to a narrow belt around the shoreline of the world's oceans, where they cover less than 7 million km2, vegetated coastal habitats support about 1 to 10 % of the global marine net primary production and generate a large organic carbon surplus of about 40 % of their net primary production (NPP), which is either buried in sediments within these habitats or exported away. Large, 10-fold uncertainties in the area covered by vegetated coastal habitats, along with variability about carbon flux estimates, result in a 10-fold bracket around the estimates of their contribution to organic carbon sequestration in sediments and the deep sea from 73 to 866 Tg C yr−1, representing between 3 % and 1∕3 of oceanic CO2 uptake. Up to 1∕2 of this carbon sequestration occurs in sink reservoirs (sediments or the deep sea) beyond these habitats. The organic carbon exported that does not reach depositional sites subsidizes the metabolism of heterotrophic organisms. In addition to a significant contribution to organic carbon production and sequestration, vegetated coastal habitats contribute as much to carbonate accumulation as coral reefs do. While globally relevant, the magnitude of global carbon fluxes supported by salt-marsh, mangrove, seagrass and macroalgal habitats is declining due to rapid habitat loss, contributing to loss of CO2 sequestration, storage capacity and carbon subsidies. Incorporating the carbon fluxes' vegetated coastal habitats' support into depictions of the carbon budget of the global ocean and its perturbations will improve current representations of the carbon budget of the global ocean.

Joint production of timber, carbon, and wildlife habitat in the Canadian boreal plains

2008 ◽  
Vol 38 (6) ◽  
pp. 1478-1492 ◽  
Author(s):  
Geoffrey R. McCarney ◽  
Glen W. Armstrong ◽  
Wiktor L. Adamowicz
Keyword(s):  
Carbon Budget ◽  
Management Practices ◽  
Forest Cover ◽  
Natural Disturbance ◽  
Wildlife Habitat ◽  
Joint Production ◽  
Timber Supply ◽  
Budget Model ◽  
Carbon Budget Model ◽  
Trade Offs

This study investigates the relationships and trade-offs between forest carbon management, sustained timber yield, and the production of wildlife habitat to provide a more complete picture of the costs and challenges faced by forest managers for a particular case study in Canada’s boreal mixedwood region. The work presented is an extension of a previously published model that analysed the joint production of timber supply and wildlife habitat using a natural disturbance model approach to ecosystem management. The primary contribution of the present study is the detailed incorporation of a carbon budget model into the framework developed previously. Using the Carbon Budget Model of the Canadian Forest Sector, dynamics specific to separate biomass and dead organic matter carbon pools are represented for individual forest cover types. Results indicate the potential for cost thresholds in the joint production of timber supply and carbon sequestration. These thresholds are linked to switch points in the decision between multiple use and specialized land management practices. Cobenefits in the production of carbon and wildlife habitat are shown to depend on ecological parameters, harvest flow regulations, and incentives for timber supply provided by the market.

scholarly journals Using the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to examine the impact of harvest and fire on carbon dynamics in selected forest types of the Canadian Boreal shield

2012 ◽  
Vol 88 (04) ◽  
pp. 426-438 ◽  
Author(s):  
N. Luckai ◽  
G.R. Larocque ◽  
L. Archambault ◽  
D. Paré ◽  
R. Boutin ◽  
...  
Keyword(s):  
Carbon Budget ◽  
Jack Pine ◽  
Forest Sector ◽  
Forest Types ◽  
Deep Soil ◽  
Budget Model ◽  
Carbon Budget Model ◽  
Fire Disturbances ◽  
Shallow Soils ◽  
The Impact

The objective of the study was to assess the responsiveness of the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to management scenarios that included three rotation lengths (50, 100 and 250 years) under harvest and fire disturbances in six forest types (poplar deep soil, black spruce deep soil, jack pine deep and shallow soils, hardwood mixedwood and other conifer lowland). Outputs from five carbon (C) pools were considered: merchantable stemwood (stump height of 30 cm, minimum DBH of 9 cm and a minimum top diameter of 7 cm), deadwood, soil C, total ecosystem C and cumulative total ecosystem C emissions. Yield curves strongly affected the predicted size of all five pools. Longer rotation lengths led to larger pools with the relative differences between rotation lengths varying with stand types. Pools associated with poplar were usually the largest while those of jack pine on shallow sites were generally the smallest. When compared to the starting point of the simulations, cumulative total ecosystem C and C emissions increased with the 100- and 250-year harvest rotations (HARV100 and HARV250, respectively) and declined with the 50-year harvest rotation (HARV50). Fire disturbances resulted in stable pools of cumulative ecosystem C and declines in C emissions. CBM-CFS3 provided realistic pool values but the authors suggest further development of the model depiction of ecosystem processes, especially with respect to the treatment of respiration. In general, the authors recommend that forest management planners consider using an integrated approach that links multiple proven and accepted models under appropriate model linking software.

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