scholarly journals Different responses of soil respiration and its components to nitrogen and phosphorus addition in a subtropical secondary forest

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Junjun Zhang ◽  
Yong Li ◽  
Jinsong Wang ◽  
Weinan Chen ◽  
Dashuan Tian ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Nitrogen Availability ◽  
Secondary Forest ◽  
Microbial Community Composition ◽  
Nitrogen And Phosphorus ◽  
Soil Nitrogen Availability ◽  
Biogeochemical Models ◽  
Subtropical Secondary Forest ◽  
Co Addition ◽  
P Addition

Abstract Background Nitrogen (N) and phosphorus (P) deposition have largely affected soil respiration (Rs) in forest ecosystems. However, few studies have explored how N and P individually or in combination to influence Rs and its components (autotrophic respiration, Ra; heterotrophic respiration, Rh), especially in highly P-limited subtropical forests. To address this question, we conducted a field manipulation experiment with N and/or P addition in a 50-year-old subtropical secondary forest. Results We found that N addition on average reduced Rs, Ra, and Rh by 15.2%, 15%, and 11.7%, respectively during 2-year field study. P addition had an inconsistent effect on Ra, with Ra increasing by 50.5% in the first year but reducing by 26.6% in the second year. Moreover, P addition on average decreased Rh by 8.9%–30.9% and Rs by 6.7%–15.6% across 2 years. In contrast, N and P co-addition on average increased Rs, Ra, and Rh by 1.9%, 7.9%, and 2.1% during the experimental period. Though Rs and Rh were significantly correlated with soil temperature, their temperature sensitivities were not significantly changed by fertilization. Ra was predominantly regulated by soil nitrogen availability (NH4+ and NO3−), soil dissolved organic carbon (DOC), and enzyme activities, while the variation in Rh was mainly attributable to changes in soil microbial community composition and soil β-D-Cellubiosidase (CB) and β-Xylosidase (XYL) activities. Conclusion Our findings highlight the contrasting responses of Rs and its components to N or P addition against N and P co-addition, which should be differentially considered in biogeochemical models in order to improve prediction of forest carbon dynamics in the context of N and P enrichment in terrestrial ecosystems.

Effect of water, temperature and fertilizers on soil nitrogen net transformations and tree growth in an elfin cloud forest of Colombia

2000 ◽  
Vol 16 (1) ◽  
pp. 83-99 ◽  
Author(s):  
Jaime Cavelier ◽  
Edmund Tanner ◽  
Johanna Santamaría
Keyword(s):  
Water Temperature ◽  
Soil Water ◽  
Nitrogen Mineralization ◽  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Cloud Forest ◽  
Mineral Nutrient ◽  
Phosphorus Fertilization ◽  
Nitrogen And Phosphorus ◽  
Soil Nitrogen Availability

(Accepted 31st July 1999)In the ‘elfin’ cloud forest of Serrania de Macuira, exchangeable ammonium and nitrate, and the rates of soil nitrogen mineralization and nitrification were measured in soil samples under different water, temperature and mineral nutrient additions. The effects of nitrogen, phosphorus and nitrogen plus phosphorus fertilization on radial trunk growth were measured in three tree species. In the cloud forest soils, concentrations of ammonium were much higher than those of nitrate. Nitrate was higher in samples collected during the afternoon than during the morning, probably as a result of leaching during the night or nitrification during the day. When samples were incubated under different water and temperature treatments, rates of nitrogen mineralization and nitrification increased more with changes in soil water content than with changes in temperature. Nitrification was significantly increased in soils amended with ammonium or with ammonium plus phosphorus, suggesting that nitrification is substrate-limited. Fertilization with nitrogen and phosphorus resulted in significantly increased girth increments in Guapira fragrans (Dum. -Cours.) Little and Rapanea guianensis Aublet. Myrcianthes fragrans (Sw.) D.C. did not respond to the fertilization. The results of this study support the hypothesis that the characteristics of montane rain forest in small and large tropical mountains (the ‘Massenerhebung’ effect) are greatly controlled by soil water conditions and related soil nitrogen availability.

scholarly journals Contrasting effects of nitrogen and phosphorus addition on soil respiration in an alpine grassland on the Qinghai-Tibetan Plateau

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Fei Ren ◽  
Xiaoxia Yang ◽  
Huakun Zhou ◽  
Wenyan Zhu ◽  
Zhenhua Zhang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Soil Respiration ◽  
Heterotrophic Respiration ◽  
Interactive Effects ◽  
Alpine Grassland ◽  
Organic Carbon Content ◽  
N Addition ◽  
Alpine Grasslands ◽  
Nitrogen And Phosphorus ◽  
P Addition

Abstract High soil organic carbon content, extensive root biomass, and low nutrient availability make alpine grasslands an important ecosystem for assessing the influence of nutrient enrichment on soil respiration (SR). We conducted a four-year (2009–2012) field experiment in an alpine grassland on the Qinghai-Tibetan Plateau to examine the individual and combined effects of nitrogen (N, 100 kg ha−1year−1) and phosphorus (P, 50 kg ha−1year−1) addition on SR. We found that both N and P addition did not affect the overall growing-season SR but effects varied by year: with N addition SR increased in the first year but decreased during the last two years. However, while P addition did not affect SR during the first two years, SR increased during the last two years. No interactive effects of N and P addition were observed, and both N addition and P addition reduced heterotrophic respiration during the last year of the experiment. N and P addition affected SR via different processes: N mainly affected heterotrophic respiration, whereas P largely influenced autotrophic respiration. Our results highlight the divergent effects of N and P addition on SR and address the important potential of P enrichment for regulating SR and the carbon balance in alpine grasslands.

Nitrogen and phosphorus co-addition stimulates soil respiration in a subtropical evergreen broad-leaved forest

2020 ◽  
Vol 450 (1-2) ◽  
pp. 171-182 ◽  
Author(s):  
Shengzhao Wei ◽  
Liehua Tie ◽  
Jiao Liao ◽  
Xing Liu ◽  
Meilin Du ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Nitrogen And Phosphorus ◽  
Broad Leaved Forest ◽  
Co Addition ◽  
Leaved Forest

scholarly journals Feedback Regulation between Aquatic Microorganisms and the Bloom-Forming Cyanobacterium Microcystis aeruginosa

2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Meng Zhang ◽  
Tao Lu ◽  
Hans W. Paerl ◽  
Yiling Chen ◽  
Zhenyan Zhang ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Microcystis Aeruginosa ◽  
Lake Taihu ◽  
Inorganic Nitrogen ◽  
Microbial Community Composition ◽  
Nitrogen And Phosphorus ◽  
Content Type ◽  
Coculture System ◽  
Eukaryotic Microorganisms ◽  
Aquatic Microorganisms

ABSTRACT The frequency and intensity of cyanobacterial blooms are increasing worldwide. Interactions between toxic cyanobacteria and aquatic microorganisms need to be critically evaluated to understand microbial drivers and modulators of the blooms. In this study, we applied 16S/18S rRNA gene sequencing and metabolomics analyses to measure the microbial community composition and metabolic responses of the cyanobacterium Microcystis aeruginosa in a coculture system receiving dissolved inorganic nitrogen and phosphorus (DIP) close to representative concentrations in Lake Taihu, China. M. aeruginosa secreted alkaline phosphatase using a DIP source produced by moribund and decaying microorganisms when the P source was insufficient. During this process, M. aeruginosa accumulated several intermediates in energy metabolism pathways to provide energy for sustained high growth rates and increased intracellular sugars to enhance its competitive capacity and ability to defend itself against microbial attack. It also produced a variety of toxic substances, including microcystins, to inhibit metabolite formation via energy metabolism pathways of aquatic microorganisms, leading to a negative effect on bacterial and eukaryotic microbial richness and diversity. Overall, compared with the monoculture system, the growth of M. aeruginosa was accelerated in coculture, while the growth of some cooccurring microorganisms was inhibited, with the diversity and richness of eukaryotic microorganisms being more negatively impacted than those of prokaryotic microorganisms. These findings provide valuable information for clarifying how M. aeruginosa can potentially modulate its associations with other microorganisms, with ramifications for its dominance in aquatic ecosystems. IMPORTANCE We measured the microbial community composition and metabolic responses of Microcystis aeruginosa in a microcosm coculture system receiving dissolved inorganic nitrogen and phosphorus (DIP) close to the average concentrations in Lake Taihu. In the coculture system, DIP is depleted and the growth and production of aquatic microorganisms can be stressed by a lack of DIP availability. M. aeruginosa could accelerate its growth via interactions with specific cooccurring microorganisms and the accumulation of several intermediates in energy metabolism-related pathways. Furthermore, M. aeruginosa can decrease the carbohydrate metabolism of cooccurring aquatic microorganisms and thus disrupt microbial activities in the coculture. This also had a negative effect on bacterial and eukaryotic microbial richness and diversity. Microcystin was capable of decreasing the biomass of total phytoplankton in aquatic microcosms. Overall, compared to the monoculture, the growth of total aquatic microorganisms is inhibited, with the diversity and richness of eukaryotic microorganisms being more negatively impacted than those of prokaryotic microorganisms. The only exception is M. aeruginosa in the coculture system, whose growth was accelerated.

Sign in / Sign up

Export Citation Format

Share Document