Mechanisms of biodiversity loss under nitrogen enrichment: unveiling a shift from light competition to cation toxicity

New Phytologist, Journal Year: 2024, Volume and Issue: 243(5), P. 1966 - 1979

Published: July 6, 2024

Summary The primary mechanisms contributing to nitrogen (N) addition induced grassland biodiversity loss, namely light competition and soil cation toxicity, are often examined separately in various studies. However, their relative significance governing loss along N gradient remains unclear. We conducted a 4‐yr field experiment with five rates (0, 2, 10, 20, 50 g m −2 yr −1 ) performed meta‐analysis using global data from 239 observations N‐fertilized ecosystems. Results our indicate that both (e.g. Mn 2+ Al 3+ toxicity contribute plant diversity under enrichment. importance of these varied enrichment intensity. Light played more significant role influencing species richness low (≤ 10 ), while became increasingly dominant reducing high (>10 ). Therefore, transition occurs increasing availability. These findings imply the is regulated by distinct mechanisms, necessitating adoption differential management strategies mitigate varying intensities

Language: Английский

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Long-term nitrogen and phosphorus fertilization improved crop yield by influencing rhizosphere nitrogen transformation processes

Applied Soil Ecology, Journal Year: 2025, Volume and Issue: 208, P. 105968 - 105968

Published: Feb. 18, 2025

Language: Английский

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Labile carbon inputs offset nitrogen-induced soil aggregate destabilization via enhanced growth of saprophytic fungi in a meadow steppe

Geoderma, Journal Year: 2024, Volume and Issue: 443, P. 116841 - 116841

Published: March 1, 2024

The formation and stability of soil aggregates affect plant growth, carbon sequestration, many other physiological biogeochemical processes. Aggregates may be destabilized by nitrogen (N) deposition due to decreased inputs binding materials; however, the legacy effects which are unknown. An increase in labile (C) input could mitigate negative impacts N addition on aggregate through improvement physical, chemical biological conditions. Using a field experiment with NH4NO3 at multiple levels meadow steppe, we terminated sixth year shifted applying C form sucrose three (C-0, C-200, C-2000 g m−2 y−1) for two years. Then examined size distribution associated properties. high historical rates proportion macroaggregates (>2000 μm) increased microaggregates (<250 μm), leading reduction mean weight diameter (MWD), an index aggregation stability. Labile offset hierarchy reversed N-induced changes MWD. did not pH exchangeable Ca2+, but microbial biomass (MBC) relative abundance saprotrophic fungi (SSF); whilst C-200 arbuscular mycorrhizal (AMF) only low (

Language: Английский

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Afforestation increases soil inorganic N supply capacity and lowers plant N limitation in subtropical karst areas

Geoderma, Journal Year: 2024, Volume and Issue: 443, P. 116848 - 116848

Published: March 1, 2024

The positive effects of afforestation in karst rocky desertification areas are often limited by soil nitrogen (N) availability. However, how plant N limitation evolves response to prolonged as well the mechanisms underlying and availability poorly understood. In this study, leaves samples were collected from cropland, Dodonaea viscosa plantations 10, 20 40 years after their establishment on abandoned cropland a area. natural succession shrubland served control. Foliar N/phosphorus (P) stoichiometry was used evaluate limitation, concentration δ15N value foliar measured changes Soil transformation rates also determined, using 15N tracing technique elucidate mechanism inorganic community-level N/P ratio (13.5) lower than 14 following 10-y afforestation, indicating that growth is predominantly limited. With increased 14.0–15.5, suggesting decreased limitation. This could be attributed confirmed raises with afforestation. Compared D. supply capacity, stimulating organic mineralization, heterotrophic nitrification release adsorbed ammonium, more obviously ammonium correlated significantly positively concentration, ratio, δ15N, larger alleviates effect can increases matter content, bacterial fungal abundances structure improvement all which facilitate mineralization nitrification. still exists, monoculture may need adapted maximize alleviate areas.

Language: Английский

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Nitrogen application increases the productivity of perennial alpine cultivated grassland by improving soil physicochemical properties and microbial community characteristics

Plant and Soil, Journal Year: 2024, Volume and Issue: unknown

Published: May 25, 2024

Language: Английский

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Differential responses of soil phosphorus fractions to varied nitrogen compound additions in a meadow steppe

Journal of Environmental Management, Journal Year: 2024, Volume and Issue: 369, P. 122337 - 122337

Published: Sept. 1, 2024

Language: Английский

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Linking Changes in Plant Growth and Nutrient Stoichiometry With Nitrogen Enrichment in a Meadow Steppe

Journal of Geophysical Research Biogeosciences, Journal Year: 2025, Volume and Issue: 130(1)

Published: Jan. 1, 2025

Abstract Exogenous nitrogen (N) inputs can significantly influence the availability of N and other nutrients in terrestrial ecosystems. However, connections between soil nutrient dynamics following enrichment plant uptake as well growth responses within a community remain underexplored. Here, we examined effects addition on several macro micronutrients three dominant plants meadow steppe China. The results showed that (a) exchangeable Ca Mg initially increased when rate was lower than 10 g m −2 yr −1 then decreased at higher rates (10–50 ), whereas available P extractable Fe, Mn, Cu remained relatively stable low but high rates. (b) response concentrations stoichiometry these to not only species‐specific also marked differences especially for those micronutrients. (c) Species with variation concentrations, such Leymus chinensis ( Lc ) Thermopsis lanceolata Tl exhibited (for or biomass after addition, species Carex duriuscula , greater variability, experienced reduced biomass. These findings suggest acidification induced by exogenous alters further imbalanced stoichiometries, which will affect structures communities under global change scenarios.

Language: Английский

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Labile carbon input alleviates nitrogen‐induced community instability in a meadow steppe

Journal of Ecology, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 14, 2025

Abstract Global nitrogen (N) deposition continues to threaten plant diversity and ecosystem stability despite a recent slowdown in its increasing rates. Labile carbon (C) may help reduce excess N by alleviating microbial C starvations, but their role mitigating the harmful effects of enrichment remains unclear. In meadow steppe northern China, we conducted 9‐year (2014–2022) field experiment with six levels historical addition (0, 2, 5, 10, 20, 50 g m −2 year −1 , 2014–2019) three labile 200, 2000 ). Three years after ceasing treatments (2020–2022), above‐ground net primary productivity (ANPP) remained high under addition. However, species richness community continued decline reduced dominance certain within while it enhanced asynchrony below‐ground (BNPP). Boosted regression tree models indicated that inputs improved enhancing BNPP, which increased relative importance BNPP from 7.5% 27.4% as input rose. Synthesis . Our results highlight how can counteract negative impacts on via plant‐microbe competition biomass allocation.

Language: Английский

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Global change and China's terrestrial carbon sink: A quantitative review of 30 years' ecosystem manipulative experiments

Ecological Monographs, Journal Year: 2025, Volume and Issue: 95(1)

Published: Feb. 1, 2025

Abstract Quantifying terrestrial carbon (C) sequestration potential is crucial for climate change mitigation and achieving C neutrality. Ecosystem manipulative experiments (EMEs) provide valuable in situ assessments of dynamics under global change. Although EMEs have expanded rapidly China, their current state role elucidating spatial drivers the country's sink responses to major factors remain underexplored. This study systematically reviewed 1140 publications on Chinese EMEs, compiling a dataset net primary productivity (NPP) ecosystem (NEP). We identified 558 China since 1991, marked by two phases: (1) preliminary stage (1991–2004) (2) exponential growth (2005–present). Most focused grasslands, with limited emphasis CO 2 enrichment studies Northwest China. Our findings revealed that China's ecosystems serve as significant (positive NEP), strength positively associated temperature, soil clay, silt, nitrogen (N) contents, negatively sand content bulk density. Optimal conditions NPP NEP were observed at precipitation levels 850–1176 mm pH between 6.5 7.0. Elevated stimulated when combined N addition, particularly organic N, effects varied temperature texture (clay, contents). Warming impacts differed facility type, reducing wetlands open‐top chambers. Combined warming water or addition generally increased NEP, while coupling it reduced caused declines. above 1.5°C often had adverse impacts. Both responded nonlinearly precipitation, exhibiting negative asymmetry anomalies. Nitrogen consistently influenced application rates, frequency, duration, pH. Additive common. To improve our understanding feedbacks anthropogenic changes, future research should focus long‐term, multifactor mature forests wetlands, aiding pursuit net‐zero targets.

Language: Английский

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Differential impacts of nitrogen compounds on soil acid phosphatase activity in a meadow steppe

Ecological Processes, Journal Year: 2025, Volume and Issue: 14(1)

Published: March 12, 2025

Abstract Background Nitrogen (N) addition profoundly alters soil phosphatase activities and induces widespread microbial phosphorus (P) limitation in grassland ecosystems. However, the long-term effects of different rates chemical forms N on acid (ACP) activity P availability remain unclear. Here, based a 10-year experiment, we investigated range (0–50 g m −2 yr −1 ) applied as either (NH 4 2 SO or urea ACP northern China meadow steppe, with without mowing management. Results We found that remained unaffected by until certain thresholds were reached (< 10 for [(NH ] < 20 urea), beyond which it declined sharply. exerted stronger inhibitory effect compared to urea, former primarily acting through acidification latter decrease bacterial diversity. In contrast, regimes did not significantly alter under form. Conclusions Our findings underscore necessity accounting both when assessing atmospheric deposition impacts activity. These results inform development management strategies mitigate declines enzyme enhance sustainability

Language: Английский

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