scholarly journals Impact of nitrogen fertilization on soil respiration and net ecosystem production in maize

2018 ◽  
Vol 64 (No. 8) ◽  
pp. 353-360 ◽  
Author(s):  
Lamptey Shirley ◽  
Li Lingling ◽  
Xie Junhong
Keyword(s):  
Soil Respiration ◽  
Primary Production ◽  
Soil Water ◽  
Nitrogen Fertilization ◽  
Field Experiments ◽  
Net Primary Production ◽  
Net Ecosystem Production ◽  
Water Dynamics ◽  
Ecosystem Production ◽  
Heavy Carbon

Agriculture in the semi-arid is often challenged by overuse of nitrogen (N), inadequate soil water and heavy carbon emissions thereby threatening sustainability. Field experiments were conducted to investigate the effect of nitrogen fertilization levels (N<sub>0</sub> – 0, N<sub>100</sub> – 100, N<sub>200</sub> – 200, N<sub>300</sub> – 300 kg N/ha) on soil water dynamics, soil respiration (Rs), net ecosystem production (NEP), and biomass yields. Zero nitrogen soils decreased Rs by 23% and 16% compared to N<sub>300</sub> and N<sub>200</sub> soils, respectively. However, biomass yield was greatest under N<sub>300</sub> compared with N<sub>0</sub>, which therefore translated into increased net primary production by 89% and NEP by 101% compared to N<sub>0</sub>. To a lesser extent, N<sub>200</sub> increased net primary production by 69% and net ecosystem production by 79% compared to N<sub>0</sub>. Grain yields were greatest under N<sub>300</sub> compared with N<sub>100</sub> and N<sub>0</sub>, which therefore translated into increased carbon emission efficiency (CEE) by 53, 39 and 3% under N<sub>300</sub> compared to N<sub>0</sub>, N<sub>100</sub> and N<sub>200</sub> treatments, respectively. There appears potential for 200 kg N/ha to be used to improve yield and increase CEE.

scholarly journals Land Cover and Land Use Change Decreases Net Ecosystem Production in Tropical Peatlands of West Kalimantan, Indonesia

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1587
Author(s):  
Imam Basuki ◽  
J. Boone Kauffman ◽  
James T. Peterson ◽  
Gusti Z. Anshari ◽  
Daniel Murdiyarso
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Soil Respiration ◽  
Primary Production ◽  
Oil Palm ◽  
Net Primary Production ◽  
Net Ecosystem Production ◽  
Carbon Sinks ◽  
Peat Swamp ◽  
Ecosystem Production

Deforested and converted tropical peat swamp forests are susceptible to fires and are a major source of greenhouse gas (GHG) emissions. However, information on the influence of land-use change (LUC) on the carbon dynamics in these disturbed peat forests is limited. This study aimed to quantify soil respiration (heterotrophic and autotrophic), net primary production (NPP), and net ecosystem production (NEP) in peat swamp forests, partially logged forests, early seral grasslands (deforested peat), and smallholder-oil palm estates (converted peat). Peat swamp forests (PSF) showed similar soil respiration with logged forests (LPSF) and oil palm (OP) estates (37.7 Mg CO2 ha−1 yr−1, 40.7 Mg CO2 ha−1 yr−1, and 38.7 Mg CO2 ha−1 yr−1, respectively), but higher than early seral (ES) grassland sites (30.7 Mg CO2 ha−1 yr−1). NPP of intact peat forests (13.2 Mg C ha−1 yr−1) was significantly greater than LPSF (11.1 Mg C ha−1 yr−1), ES (10.8 Mg C ha−1 yr−1), and OP (3.7 Mg C ha−1 yr−1). Peat swamp forests and seral grasslands were net carbon sinks (10.8 Mg CO2 ha−1 yr−1 and 9.1 CO2 ha−1 yr−1, respectively). In contrast, logged forests and oil palm estates were net carbon sources; they had negative mean Net Ecosystem Production (NEP) values (−0.1 Mg CO2 ha−1 yr−1 and −25.1 Mg CO2 ha−1 yr−1, respectively). The shift from carbon sinks to sources associated with land-use change was principally due to a decreased Net Primary Production (NPP) rather than increased soil respiration. Conservation of the remaining peat swamp forests and rehabilitation of deforested peatlands are crucial in GHG emission reduction programs.

Temporal changes of forest net primary production and net ecosystem production in west central Canada associated with natural and anthropogenic disturbances

2003 ◽  
Vol 33 (12) ◽  
pp. 2340-2351 ◽  
Author(s):  
Zhong Li ◽  
Michael J Apps ◽  
Werner A Kurz ◽  
Ed Banfield
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Anthropogenic Disturbances ◽  
Temporal Variations ◽  
Net Ecosystem Production ◽  
Forest Sector ◽  
Natural Disturbances ◽  
Carbon Budget Model ◽  
West Central ◽  
Ecosystem Production

Temporal variations of net primary production (NPP) and net ecosystem production (NEP) in west central Canadian forests over the period of 1920–1995 and their responses to natural and anthropogenic disturbances were simulated using the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS2). The results show that forest NPP in the region was 215 g C·year–1·m–2 in 1920, varied between 105 and 317 g·C year–1·m–2 depending on ecoclimatic province, but gradually increased to 330 (158 to 395) g C·year–1·m–2 in the early 1980s before declining to 290 (148 to 395) g C·year–1·m–2 by 1995. Forest NEP was estimated to be 53 (–13 to 88) g C·year–1·m–2 in 1920–1924, increased to 75 (5 to 98) g C·year–1·m–2 in 1960, and then declined to 26 (–14 to 53) g C·year–1·m–2 in 1991–1995. Natural disturbances played a greater role than harvest in determining the temporal pattern of forest NPP and NEP during the period because of the larger area affected by natural disturbances. This study also indicated that ignoring disturbances would lead to an overestimation of forest NPP and NEP in ecosystem modeling.

scholarly journals North American boreal forests are a large carbon source due to wildfires from 1986 to 2016

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bailu Zhao ◽  
Qianlai Zhuang ◽  
Narasinha Shurpali ◽  
Kajar Köster ◽  
Frank Berninger ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Net Primary Production ◽  
Net Ecosystem Production ◽  
Ecosystem Dynamics ◽  
Burn Severity ◽  
Fire Emissions ◽  
Terrestrial Ecosystem Model ◽  
C Balance ◽  
Ecosystem Production ◽  
The Impact

AbstractWildfires are a major disturbance to forest carbon (C) balance through both immediate combustion emissions and post-fire ecosystem dynamics. Here we used a process-based biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to simulate C budget in Alaska and Canada during 1986–2016, as impacted by fire disturbances. We extracted the data of difference Normalized Burn Ratio (dNBR) for fires from Landsat TM/ETM imagery and estimated the proportion of vegetation and soil C combustion. We observed that the region was a C source of 2.74 Pg C during the 31-year period. The observed C loss, 57.1 Tg C year−1, was attributed to fire emissions, overwhelming the net ecosystem production (1.9 Tg C year−1) in the region. Our simulated direct emissions for Alaska and Canada are within the range of field measurements and other model estimates. As burn severity increased, combustion emission tended to switch from vegetation origin towards soil origin. When dNBR is below 300, fires increase soil temperature and decrease soil moisture and thus, enhance soil respiration. However, the post-fire soil respiration decreases for moderate or high burn severity. The proportion of post-fire soil emission in total emissions increased with burn severity. Net nitrogen mineralization gradually recovered after fire, enhancing net primary production. Net ecosystem production recovered fast under higher burn severities. The impact of fire disturbance on the C balance of northern ecosystems and the associated uncertainties can be better characterized with long-term, prior-, during- and post-disturbance data across the geospatial spectrum. Our findings suggest that the regional source of carbon to the atmosphere will persist if the observed forest wildfire occurrence and severity continues into the future.

scholarly journals Consistent Effects of Canopy vs. Understory Nitrogen Addition on Soil Respiration and Net Ecosystem Production in Moso Bamboo Forests

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1427
Author(s):  
Chunju Cai ◽  
Zhihan Yang ◽  
Liang Liu ◽  
Yunsen Lai ◽  
Junjie Lei ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Carbon Cycling ◽  
Forest Canopy ◽  
Carbon Sink ◽  
N Deposition ◽  
Net Ecosystem Production ◽  
Moso Bamboo ◽  
Atmospheric N Deposition ◽  
Ecosystem Carbon ◽  
Ecosystem Production

Nitrogen (N) deposition has been well documented to cause substantial impacts on ecosystem carbon cycling. However, the majority studies of stimulating N deposition by direct N addition to forest floor have neglected some key ecological processes in forest canopy (e.g., N retention and absorption) and might not fully represent realistic atmospheric N deposition and its effects on ecosystem carbon cycling. In this study, we stimulated both canopy and understory N deposition (50 and 100 kg N ha−1 year−1) with a local atmospheric NHx:NOy ratio of 2.08:1, aiming to assess whether canopy and understory N deposition had similar effects on soil respiration (RS) and net ecosystem production (NEP) in Moso bamboo forests. Results showed that RS, soil autotrophic (RA), and heterotrophic respiration (RH) were 2971 ± 597, 1472 ± 579, and 1499 ± 56 g CO2 m−2 year−1 for sites without N deposition (CN0), respectively. Canopy and understory N deposition did not significantly affect RS, RA, and RH, and the effects of canopy and understory N deposition on these soil fluxes were similar. NEP was 1940 ± 826 g CO2 m−2 year−1 for CN0, which was a carbon sink, indicating that Moso bamboo forest the potential to play an important role alleviating global climate change. Meanwhile, the effects of canopy and understory N deposition on NEP were similar. These findings did not support the previous predictions postulating that understory N deposition would overestimate the effects of N deposition on carbon cycling. However, due to the limitation of short duration of N deposition, an increase in the duration of N deposition manipulation is urgent and essential to enhance our understanding of the role of canopy processes in ecosystem carbon fluxes in the future.

Soil respiration and net ecosystem production in relation to intensive management in Moso bamboo forests

CATENA ◽  
2016 ◽  
Vol 137 ◽  
pp. 219-228 ◽  
Author(s):  
Xiaolu Tang ◽  
Shaohui Fan ◽  
Lianghua Qi ◽  
Fengying Guan ◽  
Manyi Du ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Net Ecosystem Production ◽  
Moso Bamboo ◽  
Intensive Management ◽  
Ecosystem Production
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