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1

Effects of Increased Precipitation and Nitrogen Deposition on Methane Uptake of Alpine Meadow in Qinghai-Tibet Plateau : in situ Experiments

Guo Xiaowei, Dail Licong, Zhang Fawei, Li Yikang, Lin Li, Li Qian, Dawen Qian, Fan Bo, Ke Xun, Cao Guangmin, Zhou Huakun, Du Yangong

Polish Journal of Ecology

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2020

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Vol. 68, nr 2

109--120

EN

The methane (CH4) fluxes in grasslands are sensitive to changes in precipitation and soil nitrogen concentrations, which was poorly understood, especially on the Tibetan Plateau. Therefore, an experiment was conducted from May 2012 to October 2013, by using the static chamber technique and gas chromatography method. We set up five treatments: an increased 2 g m-2 NH4NO3 treatment (2gN); an increased 4 g m-2 NH4NO3 treatment (4gN); and treatment with precipitation increased by 20% (Pre), and added 2 g m-2 NH4NO3 and precipitation (20%) treatment (N+Pre), and a control treatment (CK). The five treatments showed decreasing CH4 uptake rates in the following order: CK (71.66 ± 6.6 µg m-2 h-1) > N+Pre (58.57 ± 3.7 µg m-2 h-1) > Pre (52.66 ± 2.3 µg m-2 h-1) > 2gN (47.63 ± 3.1 µg m-2 h-1) > 4gN (39.12 ± 3.3 µg m-2 h-1). The 2gN and 4gN treatment resulted in 33.5% and 45.4% lower CH4 uptake than the CK treatment, respectively. The path analysis indicated that the above-ground biomass and litter fall were the most important factor promoting and limiting the CH4 uptake rate of alpine meadow, respectively.

2

Impact of Extra Nitrogen on Ecological Stoichiometry of Alpine Grasslands on Tibetan Plateau : Meta-Analysis

Zhang H. R., Sun W., Li S. W., Han F. S., Yu C. Q., Zhang X. Z., Wang J. S., He Y. T., Zhong Z. M.

Polish Journal of Ecology

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2018

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Vol. 66, nr 4

315--324

EN

The general impact of extra nitrogen on ecological stoichiometry was examined in alpine grasslands on the Tibetan Plateau. Extra nitrogen increased the ratio of nitrogen to phosphorus (N:P ratio) in leaves and aboveground parts of plants by 43.4% and 32.7%, respectively. In contrast, extra nitrogen reduced the ratio of carbon to nitrogen (C:N ratio) in leaves by 30.6%. Extra nitrogen decreased soil C:N ratio by 9.1% in alpine meadows, but increased soil C:N ratio by 3.4% in alpine steppes. Extra urea had a stronger positive impact on aboveground vegetation N:P ratio than did extra ammonium nitrate. Extra urea rather than ammonium nitrate decreased aboveground vegetation C:N ratio and soil C:N ratio. The impact of extra nitrogen on aboveground vegetation N:P ratio was positively correlated with latitude, mean annual temperature and precipitation, nitrogen application rate and accumulated amount, but negatively correlated with elevation, duration and aboveground vegetation N:P ratio of the control plots. The impact of extra nitrogen on leaves N:P ratio was positively correlated with nitrogen application rate and accumulated amount. The impact of extra nitrogen on leaves C:N ratio was positively correlated with latitude, but negatively correlated with mean annual temperature and precipitation, nitrogen application rate, accumulated amount, duration and leaves C:N ratio of the control plots. Therefore, nitrogen enrichment caused by human activities will most likely alter element balance and alpine plants from nitrogen limitation to phosphorus limitation. This effect may weaken with time, and increase with climatic warming, increased precipitation and nitrogen input rate.

3

Effects of CO2 Fumigation and Nitrogen Addition on Soil Respiration in a Wetland Ecosystem : Experimental Approach with Top Open Chambers

Wang J., Fu X., Wang J., Zhong H., Zhang R., Ni H.

Polish Journal of Ecology

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2018

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Vol. 66, nr 2

102--113

EN

Soil respiration plays a crucial role in global carbon cycling of terrestrial ecosystems. Changes in atmospheric CO2 and nitrogen (N) addition across the globe are likely to affect soil respiration. However, the effects of elevated CO2, and N addition on soil respiration are not fully understood especially in wetland ecosystems. To evaluate the effects of atmospheric CO2 and N availability on soil respiration, a paired, nested manipulative in situ experiment was performed, using CO2 fumigation within Open-Top Chambers as the primary factor, and N (as NH4NO3) as the secondary factor in a temperate wetland in northeastern China in 2010 and 2011. CO2 fumigation significantly enhanced soil respiration, according to repeated-measures ANOVA, and the stimulatory effect of CO2 fumigation on soil respiration was sustained during the whole experimental period regardless of N addition. However, the positive soil respiration effect of N addition alone weakened over time. Moreover, there was a significant interaction between CO2 fumigation and N addition. Soil temperature explained 50-66% of the variation in soil respiration. Moreover, soil respiration was positively correlated with the root N content and litter decomposition rate. The results suggested that elevated CO2 concentrations will accelerate soil respiration and ecosystem carbon cycling, thus, limiting soil carbon sequestration, especially when coupled with increasing N deposition.

4

Przekroczenia ładunków krytycznych na obszarach Natura 2000 w Polsce : stan obecny i prognozowany wpływ przyszłych scenariuszy depozycji azotu i siarki

Pecka T., Ulańczyk R., Mill W.

Przemysł Chemiczny

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2016

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T. 95, nr 3

519--522

PL

Przedstawiono zastosowanie koncepcji ładunków krytycznych zakwaszenia i eutrofizacji, opracowanej w ramach prac Konwencji w sprawie transgranicznego zanieczyszczania powietrza na dalekie odległości, do prognozowania narażenia ekosystemów lądowych na obszarach Natura 2000 na nadmierne depozycje atmosferyczne związków siarki i azotu przewidywane do 2020 r. w ramach rewizji Protokołu z Göteborga do tej Konwencji. Na podstawie analizy scenariuszy depozycji zanieczyszczeń przewiduje się dalszy spadek zagrożenia zakwaszeniem ekosystemów lądowych w wyniku zmniejszenia emisji związków siarki w ostatnich dekadach. Obecnie dużym wyzwaniem w Europie wydaje się być konieczność dalszego zmniejszania emisji związków azotu, których nadmierna depozycja może powodować znaczące zagrożenie dla różnorodności biologicznej.

EN

Crit. loads of acidification and eutrophication were calcd. for Natura 2000 areas in Poland by the internationally approved methodol. under the Convention on long-range transboundary air pollution. The S and N deposition scenarios until 2020 were used to calc. the crit. load exceedances, and to indicate the ecosystems with a risk due to acidification or eutrophication. The threats of acidification were significantly reduced because of the large S emission redn. The ecosystems with a risk due to N deposition is still remaining as the largest challenge for further N emission redn. both in Poland and in Europe.

5

Modelowanie depozycji związków azotowych pojawiających się w strefie ujęcia „Grotowice”

Landwójtowicz A

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2015

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z. 105

121-124

EN

This presents an analysis of modeling the deposition of nitrogen compounds fed to the surface area of water intake on the water quality intake "Grotowice" near Opole. The analysis carried out of land use allowed for the identification of major risk factors for water quality. Based on studies was estimated factors which may constitute the greatest threat to groundwater. Based on the conducted analysis, conclusions for further research were formulated.

6

Interactive effects of nitrogen and water addition on competitive hierarchies between early- and late-successional plant species

Jiang L., Lan Z., Liu G., Kardol P.

Polish Journal of Ecology

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2014

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Vol. 62, nr 4

665--678

EN

Increased nitrogen (N) and water availability, resulting from global changes or ecosystem management, were predicted to promote plant productivity and change community composition through shifts in competition hierarchies. So far, however, it still remains unclear how competitive interactions respond to N and water additions, which will be important to understand how plant community composition changes. To test plant competition ability in different successional stages under N and water addition treatments, a pot experiment under field conditions was performed. Six dominant plant species, three early-successional species, Artemisia lavandulaefolia, Artemisia capillaris, and Pennisetum centrasiaticum versus three late-successional species, Stipa krylovii, Leymus chinensis, and Artemisia frigida, were grown in monocultures and in two-species mixtures under factorial combinations of N and water addition treatments. We found that (1) there were interactive effects of N addition, water addition and interspecific competition on plant biomass; (2) For a given species, competitive abilities were correlated with biomass difference of neighboring species; (3) N and water additions interactively increased competition intensity and shifted species competitive hierarchies; (4) Late- successional species had stronger competitive abilities in the N addition treatment, whereas early-successional species had stronger competitive abilities after water addition or N + water addition. Our results show that N and water additions increased the intensity and impact of interspecific competition on plant growth, which has great implications for community structures. Since interspecific differences in competitive abilities were not well explained by species biomass, species identity, such as plant functional traits, should be included to predict the impact of increased N and water availability on plant communities and ecosystem functions.

7

Calculation of Sulphur and Nitrogen Deposition with the Frame Model and Assessment of the Exceedance of Critical Loads in Poland

Kryza M., Mill W., Dore A., Werner M., Błaś M.

Ecological Chemistry and Engineering. S

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2013

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Vol. 20, nr 2

279-290

EN

Sulphur and nitrogen deposition were calculated with the FRAME model and used to assess the exceedances of the critical loads for acidification and eutrophication of natural ecosystems in Poland. For the first time two tools: the FRAME and SONOX models were used jointly to provide information on ecosystems at risk. The FRAME model obtained close agreement with available sulphur and nitrogen wet deposition measurements. The total mass of sulphur deposited in Poland in year 2008 was estimated as 292 Gg S. Total deposition of nitrogen (oxidized + reduced) is 389 Gg N. 11% of the ecosystems in Poland were calculated to be at risk of acidification due to deposition of sulphur and nitrogen. In the case of eutrophication, over 95% of terrestrial ecosystems are at risk due to the large deposition of nitrogen compounds.

PL

W pracy zastosowano model FRAME do obliczenia informacji o depozycji związków siarki i azotu w Polsce. Na tej podstawie określono przekroczenia ładunków krytycznych dla ekosystemów naturalnych. Po raz pierwszy dwa narzędzia, modele FRAME i SONOX, zostały zastosowane razem w celu określenia zagrożenia dla ekosystemów. Wykazano, że depozycja siarki i azotu, obliczona za pomocą modelu FRAME, jest w dobrej zgodności z dostępnymi pomiarami. Całkowita depozycja siarki, zdeponowanej w Polsce w 2008, została określona na 292 Gg S. Masa zdeponowanych związków azotu (utlenionego i zredukowanego) to 389 Gg N. Wykazano, że 11% ekosystemów w Polsce jest zagrożonych nadmiernym zakwaszeniem w wyniku depozycji atmosferycznej siarki i azotu, a ponad 95% ekosystemów lądowych jest zagrożonych eutrofizacją w wyniku depozycji związków azotu.

8

Modelling of atmospheric nitrogen deposition effects to polish terrestrial ecosystems for various emission scenarios until the target year 2020

Pecka T., Mill W.

Environment Protection Engineering

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2012

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Vol. 38, nr 3

133--143

EN

Biogeochemical effects to Polish terrestrial ecosystems resulting from atmospheric nitrogen deposition were forecasted until the target year 2020. To this end recently updated critical loads of nutrient nitrogen were applied and the nitrogen deposition projections for the sequence of decades from 1980 until the target year 2020, based on the Current Legislation (CLE) and Maximum Feasible Reductions (MFR) emission scenarios. The predictions were done by use of the Very Simple Dynamic (VSD) Model developed within the Working Group on Effects of the UN ECE Convention on the Long-Range Transboundary Air Pollution CLRTAP. The calculations were done for three main forest ecosystems and three selected semi-natural ecosystems encompassing the whole territory of Poland with the spatial resolution defined by a grid cell of 1*1 km size. The study concluded with maps of CLnut(N) exceedances and expected nitrogen concentrations in soil as chemical criterion, assigned to different eutrophication risk categories for each deposition scenario. The obtained results show that in spite of the realistic (CLE scenario) and extreme (MFR) nitrogen emission reductions until 2020, more than 99% and 80% of total area of terrestrial ecosystems of Poland, respectively, willbe exposed to excessive nitrogen deposition. Results of this study as well as studies done on the European scale reveal that the nitrogen emission reductions determined by the Gothenburg Protocol are still insufficient and may lead to negative ecological effects including loss of ecosystems biodiversity. This substantiates a demanding need for the revision of the CLRTAP Gothenburg Protocol.