scholarly journals The Influence of Ozone on Net Ecosystem Production of a Ryegrass–Clover Mixture under Field Conditions

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1629
Author(s):  
Thomas Agyei ◽  
Stanislav Juráň ◽  
Magda Edwards-Jonášová ◽  
Milan Fischer ◽  
Marian Švik ◽  
...  
Keyword(s):  
Trifolium Pratense ◽  
Arable Land ◽  
Growing Season ◽  
Net Ecosystem Production ◽  
Terrestrial Vegetation ◽  
The Czech Republic ◽  
Linear Mixed Effects ◽  
Ecosystem Production ◽  
Summer Maximum ◽  
The Impact

In order to understand the effect of phytotoxic tropospheric ozone (O3) on terrestrial vegetation, we quantified the impact of current O3 concentration ([O3]) on net ecosystem production (NEP) when compared to the conditions of the pre-industrial era. We compared and tested linear mixed-effects models based on [O3] and stomatal O3 flux (Fsto). The managed ryegrass–clover (Lolium perenne and Trifolium pratense) mixture was grown on arable land in the Czech Republic, Central Europe. Values of [O3] and Fsto were measured and calculated based on resistance analogy, respectively, while NEP was calculated from eddy covariance CO2 fluxes. We found the Fsto-based model more precise when compared to measured NEP. High Fsto was found even at low [O3], while broad summer maximum of [O3] was not necessarily followed by significant NEP decline, due to low soil water content leading to a low stomatal conductivity and Fsto. Comparing to low pre-industrial O3 conditions, current levels of O3 resulted in the reduction of cumulative NEP over the entire growing season, up to 29.7 and 13.5% when the [O3]-based and Fsto-based model was applied, respectively. During the growing season, an O3-induced reduction of NEP ranged between 13.1% in May and 26.2% in July when compared to pre-industrial Fsto levels. Looking to the future, high [O3] and Fsto may lead to the reduction of current NEP by approximately 13.3% on average during the growing season, but may increase by up to 61–86.6% in autumn, indicating further O3-induced acceleration of the senescence. These findings indicate the importance of Fsto and its inclusion into the models estimating O3 effects on terrestrial vegetation. The interaction between environmental factors and stomatal conductance is therefore discussed in detail.

scholarly journals The Impact of Climate Change on the Sugar Content of Grapes and the Sustainability of their Production in the Czech Republic

2020 ◽  
Vol 13 (1) ◽  
pp. 222
Author(s):  
Miroslava Navrátilová ◽  
Markéta Beranová ◽  
Lucie Severová ◽  
Karel Šrédl ◽  
Roman Svoboda ◽  
...  
Keyword(s):  
Climate Change ◽  
Czech Republic ◽  
Sugar Content ◽  
Growing Season ◽  
Vegetation Period ◽  
The Czech Republic ◽  
Impact Of Climate Change ◽  
Secondary Sources ◽  
The Impact ◽  
Growing Region

The aim of the presented article is to evaluate the impact of climate change on the sugar content of grapes in the Czech Republic during the period 2000–2019 through selected indicators on the basis of available secondary sources. Attention is focused on the developments in both the main wine-growing regions of Moravia and Bohemia. In the field of viticulture and wine-growing, the sugar content of grapes, as a basic parameter for the classification of wines, plays an important role. In the Czech Republic, the average sugar content of grapes has had a constantly growing trend. This trend is evident both in the wine-growing region of Bohemia and in the wine-growing region of Moravia. The impact of climate change, especially the gradual increase of average temperatures in the growing season, cannot be overlooked. It greatly affects, among other things, the sugar content of grapes. Calculations according to the Huglin Index and the Winkler Index were used to determine the relationship between climate and sugar content. These indexes summarize the course of temperatures during the entire vegetation period into a single numerical value. The results show that both indexes describe the effect of air temperature on sugar content in both wine regions of the Czech Republic in a statistically significant way. The Huglin Index shows a higher correlation rate. The Winkler Index proved to be less suitable for both areas. Alternatively, the Winkler Index calculated for a shorter growing season was tested, which showed a higher degree of correlation with sugar content, approaching the significance of the Huglin Index.

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

2020 ◽  
Author(s):  
Bailu Zhao ◽  
Qianlai Zhuang ◽  
Narasinha Shurpali ◽  
Kajar Köster ◽  
Frank Berninger ◽  
...  
Keyword(s):  
Net Primary Production ◽  
Net Ecosystem Production ◽  
Ecosystem Dynamics ◽  
Fire Disturbance ◽  
Burn Severity ◽  
Fire Emissions ◽  
Terrestrial Ecosystem Model ◽  
C Balance ◽  
Ecosystem Production ◽  
The Impact

Abstract Wildfires are a major disturbance to forest carbon (C) balance through both immediate combustion emissions and post-fire ecosystem dynamics. Here we use 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 is a C source of 2.74 Pg C during the 31-year period. The observed C loss, 57.1 Tg C yr-1, was attributed to fire emissions, overwhelming the net ecosystem production (1.9 Tg C yr-1) in the region. Our simulated during-fire emissions for Alaska and Canada are within the range of field measurements and other model estimates. As burn severity increases, combustion emission tended to switch from vegetation origin towards soil origin. Burn severity regulates post-fire C dynamics. Low severity fires increase soil temperature and decrease soil moisture and thus, enhance soil respiration. However, the opposite trend was found under 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.

Variation in Peak Growing Season Net Ecosystem Production Across the Canadian Arctic

2012 ◽  
Vol 46 (15) ◽  
pp. 7971-7977 ◽  
Author(s):  
Peter M. Lafleur ◽  
Elyn R. Humphreys ◽  
Vincent L. St. Louis ◽  
May C. Myklebust ◽  
Tim Papakyriakou ◽  
...  
Keyword(s):  
Canadian Arctic ◽  
Growing Season ◽  
Net Ecosystem Production ◽  
Ecosystem Production

scholarly journals The persistency evaluation of Czech varieties of Red (Trifolium pratense L.) and Alsike Clover (Trifolium hybridum L.)

2006 ◽  
Vol 54 (4) ◽  
pp. 133-138 ◽  
Author(s):  
Stanislav Hejduk
Keyword(s):  
Czech Republic ◽  
Trifolium Pratense ◽  
Arable Land ◽  
Forage Quality ◽  
Red Clover ◽  
Soil Condition ◽  
Forage Legume ◽  
The Czech Republic ◽  
Grassland Species ◽  
Trifolium Pratense L

Red clover is the most important forage legume in the Czech Republic. It is an unassuming species to climatic and soil condition, is suitable for mixtures with grasses and it is above other grassland species in forage quality. The most serious problem of red clover in grasslands is its lack of persistency (2–4 years). Considering of red clover growing area on arable land decrease and area of permanent grasslands increases, becomes persistency of varieties important attribute. The persistency of all Czech varieties was evaluated on the basis of dominance proportion investigation after 3 winters. Assessed varieties were established in mixture with grasses (60:40%). Significantly most persistent varieties were Amos 4n (24.5%), Dolina 4n (20.25 %) and Radegast 4n (19.25%). Varieties of Alsike clover were not significantly different from varieties of red clover.

scholarly journals North American Boreal Forests Are a Large Carbon Source Due to Wildfires From 1986 to 2016

2020 ◽  
Author(s):  
Bailu Zhao ◽  
Qianlai Zhuang ◽  
Narasinha Shurpali ◽  
Kajar Köster ◽  
Frank Berninger ◽  
...  
Keyword(s):  
Net Primary Production ◽  
Net Ecosystem Production ◽  
Ecosystem Dynamics ◽  
Fire Disturbance ◽  
Burn Severity ◽  
Fire Emissions ◽  
Terrestrial Ecosystem Model ◽  
C Balance ◽  
Ecosystem Production ◽  
The Impact

Abstract Wildfires are a major disturbance to forest carbon (C) balance through both immediate combustion emissions and post-fire ecosystem dynamics. Here we use 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 is a C source of 2.74 Pg C during the 31-year period. The observed C loss, 57.1 Tg C yr-1, was attributed to fire emissions, overwhelming the net ecosystem production (1.9 Tg C yr-1) in the region. Our simulated during-fire emissions for Alaska and Canada are within the range of field measurements and other model estimates. As burn severity increases, 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 opposite trend was found under 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 Photosynthetic Apparatus Efficiency of Sida Hermaphrodita Cultivated on Heavy Metals Contaminated Arable Land Under Various Fertilization Regimes

2018 ◽  
Vol 28 (1) ◽  
pp. 130-145 ◽  
Author(s):  
Szymon Rusinowski ◽  
Jacek Krzyżak ◽  
Marta Pogrzeba
Keyword(s):  
Heavy Metals ◽  
Arable Land ◽  
Photosynthetic Apparatus ◽  
Growing Season ◽  
Photosynthetic Performance ◽  
Energy Crop ◽  
Photosynthetic Parameters ◽  
Crop Species ◽  
Microbial Inoculation ◽  
The Impact

Abstract Contaminated and marginal lands are favourable place for biomass feedstock establishment, especially due to European Union directive 2009/28/EC. This strategy not only cover local demand for energy and heat but also can be valuable in those land phytomanagment. The second-generation perennial energy crop species are the most feasible for such purpose. We studied the impact of two different fertilizer treatments on plant physiological parameters associated with photosynthesis, heavy metals (HMs) and primary macronutrients accumulation in Sida hermaphrodita cultivated on HMs contaminated soil under field conditions. NPK fertilized plants showed the highest values of photosynthetic parameters at the beginning of growing season when compared to control and microbial inoculated plants. However, at the end of the growing season inoculated and control plants showed better photosynthetic performance than NPK treated. NPK fertilizer caused higher Cd and Zn shoot concentrations while microbial inoculation caused higher K and the lowest N and P concentrations in shoot. Due to Cd, Pb and Zn concentrations in plants which should not result in alleviation of photosynthetic apparatus efficiency and biomass production it could be summarize that Sida hermaphrodita is a suitable plant for cultivation on land contaminated with HMs under different fertilization regimes.

Forest Ecosystem as a Source of Co2 During Growing Season: Relation to Weather Conditions

2014 ◽  
Vol 28 (2) ◽  
pp. 239-249 ◽  
Author(s):  
Klára Taufarová ◽  
Kateřina Havránková ◽  
Alice Dvorská ◽  
Marian Pavelka ◽  
Marek Urbaniak ◽  
...  
Keyword(s):  
Weather Conditions ◽  
Growing Season ◽  
Net Ecosystem Production ◽  
Weather Extremes ◽  
Eddy Covariance Method ◽  
Growing Seasons ◽  
Ecosystem Production ◽  
Hot Days ◽  
Carbon Balances ◽  
Co2 Release

Abstract Net ecosystem production reflects the potential of the ecosystem to sequestrate atmospheric CO2. Daily net ecosystem production of a mountain Norway spruce forest of the temperate zone (Czech Republic) was determined using the eddy covariance method. Growing season days when the ecosystem was a CO2 source were examined with respect to current weather conditions. During the 2005, 2006, and 2007 growing seasons, there were 44, 65, and 39 days, respectively, when the forest was a net CO2 source. The current weather conditions associated with CO2 release during the growing seasons were: cool and overcast conditions at the beginning or end of the growing seasons characterized by a 3-year mean net ecosystem production of -7.2 kg C ha-1 day-1; overcast or/and rainy days (-23.1 kg C ha-1 day-1); partly cloudy and hot days (-11.8 kg C ha-1 day-1); and overcast and hot days (-13.5 kg C ha-1 day-1). CO2 release was the highest during the overcast or/and rainy conditions (84%, average from all years), which had the greatest impact during the major production periods. As forests are important CO2 sinks and more frequent weather extremes are expected due to climate change, it is important to predict future forest carbon balances to study the influence of heightened variability in climatic variables.

scholarly journals Reevaluating growing season length controls on net ecosystem production in evergreen conifer forests

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
David M. Barnard ◽  
John F. Knowles ◽  
Holly R. Barnard ◽  
Michael L. Goulden ◽  
Jia Hu ◽  
...  
Keyword(s):  
Growing Season ◽  
Net Ecosystem Production ◽  
Conifer Forests ◽  
Season Length ◽  
Growing Season Length ◽  
Ecosystem Production ◽  
Evergreen Conifer

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.

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