The controls on net ecosystem productivity along an Arctic transect: a model comparison with flux measurements

2000 ◽  
Vol 6 (S1) ◽  
pp. 116-126 ◽  
Author(s):  
Mathew Williams ◽  
Werner Eugster ◽  
Edward B. Rastetter ◽  
Joseph P. Mcfadden ◽  
F. Stuart Chapin Iii
Keyword(s):  
Model Comparison ◽  
Net Ecosystem Productivity ◽  
Ecosystem Productivity ◽  
Flux Measurements

scholarly journals The role of net ecosystem productivity and of inventories in climate change research: the need for “net ecosystem productivity with harvest”, NEPH

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
E. D. Schulze ◽  
R. Valentini ◽  
O. Bouriaud
Keyword(s):  
Energy Use ◽  
Carbon Sink ◽  
Net Ecosystem Productivity ◽  
Ecosystem Productivity ◽  
Climate Change Research ◽  
Main Requirement ◽  
Flux Measurements ◽  
Land Surfaces ◽  
Terrestrial Carbon Sink ◽  
Global Carbon

Abstract Background There is an urgent need for quantifying the terrestrial carbon sink in the context of global carbon emissions. However, neither the flux measurements, nor the national wood balances fulfil this purpose. In this discussion article we point at various shortcomings and necessary improvements of these approaches in order to achieve a true quantification of the carbon exchange of land surfaces. Results We discuss the necessity of incorporating all lateral fluxes, but mainly the export of biomass by harvest, into the flux balance and to recognize feedbacks between management and fluxes to make flux measurements compatible with inventories. At the same time, we discuss the necessity that national reports of wood use need to fully recognize the use of wood for energy use. Both approaches of establishing an ecosystem carbon balance, fluxes and inventories, have shortcomings. Conclusions Including harvest and feedbacks by management appears to be the main requirement for the flux approach. A better quantification of wood use for bioenergy seems a real need for integrating the national wood balances into the global carbon cycle.

scholarly journals Interannual variability of terrestrial net ecosystem productivity over China: regional contributions and climate attribution

2019 ◽  
Vol 14 (1) ◽  
pp. 014003 ◽  
Author(s):  
Li Zhang ◽  
Xiaoli Ren ◽  
Junbang Wang ◽  
Honglin He ◽  
Shaoqiang Wang ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Net Ecosystem Productivity ◽  
Ecosystem Productivity

scholarly journals Growing Season Length as a Key Factor of Cumulative Net Ecosystem Exchange Over the Pine Forest Ecosystems in Europe

2015 ◽  
Vol 29 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Alina Danielewska ◽  
Marek Urbaniak ◽  
Janusz Olejnik
Keyword(s):  
Air Temperature ◽  
Measurement Data ◽  
Growing Season ◽  
Pine Forest ◽  
Pine Forests ◽  
Net Ecosystem Productivity ◽  
Ecosystem Productivity ◽  
Season Length ◽  
Important Species ◽  
Growing Season Length

Abstract The Scots pine is one of the most important species in European and Asian forests. Due to a widespread occurrence of pine forests, their significance in the energy and mass exchange between the Earth surface and the atmosphere is also important, particularly in the context of climate change and greenhouse gases balance. The aim of this work is to present the relationship between the average annual net ecosystem productivity and growing season length, latitude and air temperature (tay) over Europe. Therefore, CO2 flux measurement data from eight European pine dominated forests were used. The observations suggest that there is a correlation between the intensity of CO2 uptake or emission by a forest stand and the above mentioned parameters. Based on the obtained results, all of the selected pine forest stands were CO2 sinks, except a site in northern Finland. The carbon dioxide uptake increased proportionally with the increase of growing season length (9.212 g C m-2 y-1 per day of growing season, R2 = 0.53, p = 0.0399). This dependency showed stronger correlation and higher statistical significance than both relationships between annual net ecosystem productivity and air temperature (R2 = 0.39, p = 0.096) and annual net ecosystem productivity and latitude (R2 = 0.47, p = 0.058). The CO2 emission surpassed assimilation in winter, early spring and late autumn. Moreover, the appearance of late, cold spring and early winter, reduced annual net ecosystem productivity. Therefore, the growing season length can be considered as one of the main factor affecting the annual carbon budget of pine forests.

scholarly journals High-resolution forest carbon flux mapping and monitoring in the Pacific Northwest with time since disturbance and disturbance legacies inferred from remote sensing and inventory data

2016 ◽  
Author(s):  
Huan Gu ◽  
Christopher A. Williams ◽  
Bardan Ghimire ◽  
Feng Zhao ◽  
Chengquan Huang
Keyword(s):  
Remote Sensing ◽  
Pacific Northwest ◽  
Forest Inventory ◽  
Stand Age ◽  
Net Ecosystem Productivity ◽  
Fine Scale ◽  
Ecosystem Productivity ◽  
Inventory Data ◽  
Forest Inventory Data ◽  
The Pacific

Abstract. Assessment of forest carbon storage and uptake is central to understanding the role forests play in the global carbon cycle and policy-making aimed at mitigating climate change. Current U.S. carbon stocks and fluxes are monitored and reported at fine-scale regionally, or coarse-scale nationally. We proposed a new methodology of quantifying carbon uptake and release across forested landscapes in the Pacific Northwest (PNW) at a fine scale (30 m) by combining remote-sensing based disturbance year, disturbance type, and aboveground biomass with forest inventory data in a carbon modelling framework. Time since disturbance is a key intermediate determinant that aided the assessment of disturbance-driven carbon emissions and removals legacies. When a recent disturbance was detected, time since disturbance can be directly determined by remote sensing-derived disturbance products; and if not, time since last stand-clearing was inferred from remote sensing-derived 30 m biomass map and field inventory-derived species-specific biomass regrowth curves. Net ecosystem productivity (NEP) was further mapped based on carbon stock and flux trajectories that described how NEP changes with time following harvest, fire, or bark beetle disturbances of varying severity. Uncertainties from biomass map and forest inventory data were propagated by probabilistic sampling to provide a probabilistic, statistical distribution of stand age and NEP for each forest pixel. We mapped mean, standard deviation and statistical distribution of stand age and NEP at 30 m in the PNW region. Our map indicated a net ecosystem productivity of 5.2 Tg C y−1 for forestlands circa 2010 in the study area, with net uptake in relatively mature (> 24 year old) forests (13.6 Tg C y−1) overwhelming net negative NEP from tracts that have seen recent harvest (−6.4 Tg C y−1), fires (−0.5 Tg C y−1), and bark beetle outbreaks (−1.4 Tg C y−1). The approach will be applied to forestlands in other regions of the conterminous U.S. to advance a more comprehensive monitoring, mapping and reporting the carbon consequences of forest change across the U.S.

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