scholarly journals Modeling topographic effects on net ecosystem productivity of boreal black spruce forests

2004 ◽  
Vol 24 (1) ◽  
pp. 1-18 ◽  
Author(s):  
R. F. Grant
Keyword(s):  
Black Spruce ◽  
Topographic Effects ◽  
Net Ecosystem Productivity ◽  
Ecosystem Productivity ◽  
Spruce Forests

scholarly journals Changes in net ecosystem productivity of boreal black spruce stands in response to changes in temperature at diurnal and seasonal time scales

2009 ◽  
Vol 29 (1) ◽  
pp. 1-17 ◽  
Author(s):  
R.F. Grant ◽  
H.A. Margolis ◽  
A.G. Barr ◽  
T.A. Black ◽  
A.L. Dunn ◽  
...  
Keyword(s):  
Time Scales ◽  
Black Spruce ◽  
Net Ecosystem Productivity ◽  
Ecosystem Productivity ◽  
Spruce Stands

Effects of seasonal and interannual climate variability on net ecosystem productivity of boreal deciduous and conifer forests

2002 ◽  
Vol 32 (5) ◽  
pp. 878-891 ◽  
Author(s):  
M A Arain ◽  
T A Black ◽  
A G Barr ◽  
P G Jarvis ◽  
J M Massheder ◽  
...  
Keyword(s):  
Populus Tremuloides ◽  
Land Surface ◽  
Black Spruce ◽  
Climatic Variability ◽  
Flux Measurement ◽  
Canopy Conductance ◽  
Net Ecosystem Productivity ◽  
Spruce Forest ◽  
Ecosystem Productivity ◽  
Aspen Forest

The response of net ecosystem productivity (NEP) and evaporation in a boreal aspen (Populus tremuloides Michx.) forest and a black spruce (Picea mariana (Mill.) BSP) forest in Canada was compared using a newly developed realistic model of surface-atmosphere exchanges of carbon dioxide (CO2), water vapor, and energy as well as eddy covariance flux measurements made over a 6-year period (1994-1999). The model was developed by incorporating a process-based two-leaf (sunlit and shaded) canopy conductance and photosynthesis submodel in the Canadian Land Surface Scheme (CLASS). A simple submodel of autotrophic and heterotrophic respiration was combined with the photosynthesis model to simulate NEP. The model performed well in simulating half-hourly, daily, and monthly mean CO2 exchange and evaporation values in both deciduous and coniferous forests. Modeled and measured results showed a linear relationship between CO2 uptake and evaporation, and for each kilogram of water transpired, approximately 3 g of carbon (C) were photosynthesized by both ecosystems. The model results confirmed that the aspen forest was a weak to moderate C sink with considerable interannual variability in C uptake. In the growing season, the C uptake capacity of the aspen forest was over twice that of the black spruce forest. Warm springs enhanced NEP in both forests; however, high mid-summer temperatures appear to have significantly reduced NEP at the black spruce forest as a result of increased respiration. The model suggests that the black spruce forest is a weak C sink in cool years and a weak C source in warm years. These results show that the C balance of these two forests is sensitive to seasonal and interannual climatic variability and stresses the importance of continuous long-term flux measurement to confirm modeling results.

scholarly journals Managing Understory Vegetation for Maintaining Productivity in Black Spruce Forests: A Synthesis within a Multi-Scale Research Model

Forests ◽  
2013 ◽  
Vol 4 (3) ◽  
pp. 613-631 ◽  
Author(s):  
Nelson Thiffault ◽  
Nicole Fenton ◽  
Alison Munson ◽  
François Hébert ◽  
Richard Fournier ◽  
...  
Keyword(s):  
Black Spruce ◽  
Understory Vegetation ◽  
Research Model ◽  
Spruce Forests ◽  
Multi Scale

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

Linking annual tree growth with eddy-flux measures of net ecosystem productivity across twenty years of observation in a mixed conifer forest

2018 ◽  
Vol 249 ◽  
pp. 479-487 ◽  
Author(s):  
Aaron Teets ◽  
Shawn Fraver ◽  
David Y. Hollinger ◽  
Aaron R. Weiskittel ◽  
Robert S. Seymour ◽  
...  
Keyword(s):  
Tree Growth ◽  
Net Ecosystem Productivity ◽  
Eddy Flux ◽  
Conifer Forest ◽  
Ecosystem Productivity ◽  
Mixed Conifer ◽  
Mixed Conifer Forest

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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