Impact of Nitrogen Deposition on Tropical Forest Biomass and Carbon Sequestration

2018 ◽  
Vol 4 (02) ◽  
pp. 60-67
Author(s):  
R. Sagar ◽  
Vijay Pratap Gautam
Keyword(s):  
Biomass Production ◽  
Nutrient Availability ◽  
Forest Ecosystems ◽  
C:N Ratio ◽  
Forest Biomass ◽  
C Sequestration ◽  
N Deposition ◽  
N Addition ◽  
Mycorrhizal Association ◽  
Use Efficiency

Undoubtedly, nitrogen (N) is an essential component of proteins and nucleic acid of cells but in the last few decades it has undergone dramatic changes. Now move nitrogen has come into circulation and thus it has now become an environmental problem. Ndeposition is not always undesirable, in areas with N- limitation , N–deposition enhances the plant growth. Besides, it sequesters more CO into the plant biomass there by 2 lowering greenhouse gas emission into the atmosphere. Forest ecosystems all around the globe have experienced N- deposition and are becoming an important C-sink which has been shown in the table 1of this review article. The C-sink capacity of forest ecosystems have been determined using many approaches which are stochiometric scaling, dynamic global vegetation models and biomass weighting method. All these method used C:N response ratio as a predictor for future rate of C-sequestration in response to N- addition. Nutrient availability increases the production of biomass per unit of photosynthesis and decreases heterotrophic respiration in forests. Nutrient availability also determines net ecosystem productivity (NEP) and ecosystem carbon use efficiency (CUE). Biomass production was found higher in the nutrient rich forests, Increase in biomass production was more in woody biomass while foliage and root biomass production remain unchanged. Indeed, the potential of forest C-sink depends upon the partitioning of the carbon uptaken during photosynthesis. In terrestrial ecosystems, C –sequestration predominantly occur in forests ecosystems. Both C:N ratio and nitrogen use efficiency (NUE) are crucial for determining C-sequestration in different forest types. C-sequestration in response to N-addition shows variation with kind of mycorrhizal association. N-deposition benefitted trees with arbuscular mycorrhizal fungi rather than ectomycorrhizal fungi. Thus, after going thoroughly across number of research articles, we arrived at the conclusion that it is the C:N ratio, NUE, forest type, nutrient availability which determine the C sequestration by forest biomass.

scholarly journals Responses of soil respiration to elevated carbon dioxide and nitrogen addition in young subtropical forest ecosystems in China

2010 ◽  
Vol 7 (1) ◽  
pp. 315-328 ◽  
Author(s):  
Q. Deng ◽  
G. Zhou ◽  
J. Liu ◽  
S. Liu ◽  
H. Duan ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Elevated Co2 ◽  
Forest Ecosystems ◽  
N Deposition ◽  
Subtropical Forest ◽  
N Addition ◽  
Above Ground Biomass ◽  
Respiration Rates ◽  
Ambient Co2 ◽  
Ambient N Deposition

Abstract. Global climate change in the real world always exhibits simultaneous changes in multiple factors. Prediction of ecosystem responses to multi-factor global changes in a future world strongly relies on our understanding of their interactions. However, it is still unclear how nitrogen (N) deposition and elevated atmospheric carbon dioxide concentration [CO2] would interactively influence forest floor soil respiration in subtropical China. We assessed the main and interactive effects of elevated [CO2] and N addition on soil respiration by growing tree seedlings in ten large open-top chambers under CO2 (ambient CO2 and 700 μmol mol−1) and nitrogen (ambient and 100 kg N ha−1 yr−1) treatments. Soil respiration, soil temperature and soil moisture were measured for 30 months, as well as above-ground biomass, root biomass and soil organic matter (SOM). Results showed that soil respiration displayed strong seasonal patterns with higher values observed in the wet season (April–September) and lower values in the dry season (October–March) in all treatments. Significant exponential relationships between soil respiration rates and soil temperatures, as well as significant linear relationships between soil respiration rates and soil moistures (below 15%) were found. Both CO2 and N treatments significantly affected soil respiration, and there was significant interaction between elevated [CO2] and N addition (p<0.001, p=0.003, and p=0.006, respectively). We also observed that the stimulatory effect of individual elevated [CO2] (about 29% increased) was maintained throughout the experimental period. The positive effect of N addition was found only in 2006 (8.17% increased), and then had been weakened over time. Their combined effect on soil respiration (about 50% increased) was greater than the impact of either one alone. Mean value of annual soil respiration was 5.32 ± 0.08, 4.54 ± 0.10, 3.56 ± 0.03 and 3.53 ± 0.03 kg CO2 m−2 yr−1 in the chambers exposed to elevated [CO2] and high N deposition (CN), elevated [CO2] and ambient N deposition (CC), ambient [CO2] and high N deposition (NN), and ambient [CO2] and ambient N deposition (CK as a control), respectively. Greater above-ground biomass and root biomass was obtained in the CN, CC and NN treatments, and higher soil organic matter was observed only in the CN treatment. In conclusion, the combined effect of elevated [CO2] and N addition on soil respiration was apparent interaction. They should be evaluated in combination in subtropical forest ecosystems in China where the atmospheric CO2 and N deposition have been increasing simultaneously and remarkably.

scholarly journals Short-Term Nitrogen Addition Does Not Significantly Alter the Effects of Seasonal Drought on Leaf Functional Traits in Machilus pauhoi Kanehira Seedlings

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 78 ◽  
Author(s):  
Hua Yu ◽  
Dongliang Cheng ◽  
Baoyin Li ◽  
Chaobin Xu ◽  
Zhongrui Zhang ◽  
...  
Keyword(s):  
Functional Traits ◽  
C:N Ratio ◽  
Leaf Traits ◽  
N Deposition ◽  
Interactive Effects ◽  
N Addition ◽  
Subtropical China ◽  
Short Term ◽  
Leaf Functional Traits ◽  
Seasonal Drought

Research Highlights: Short-term nitrogen (N) addition did not significantly alter the effects of seasonal drought on the leaf functional traits in Machilus pauhoi Kanehira seedlings in N-rich subtropical China. Background and Objectives: Seasonal drought and N deposition are major drivers of global environmental change that affect plant growth and ecosystem function in subtropical China. However, no consensus has been reached on the interactive effects of these two drivers. Materials and Methods: We conducted a full-factorial experiment to analyze the single and combined effects of seasonal drought and short-term N addition on chemical, morphological and physiological traits of M. pauhoi seedlings. Results: Seasonal drought (40% of soil field capacity) had significant negative effects on the leaf N concentrations (LNC), phosphorus (P) concentrations (LPC), leaf thickness (LT), net photosynthetic rate (A), transpiration rate (E), stomatal conductance (Gs), and predawn leaf water potential (ψPD), and significant positive effects on the carbon:N (C:N) ratio and specific leaf area (SLA). Short-term N addition (50 kg N·hm−2·year−1 and 100 kg N·hm−2·year−1) tended to decrease the C:N ratio and enhance leaf nutrient, growth, and photosynthetic performance because of increased LNC, LPC, LT, leaf area (LA), SLA, A, E, and ψPD; however, it only had significant effects on LT and Gs. No significant interactive effects on leaf traits were detected. Seasonal drought, short-term N addition, and their interactions had significant effects on soil properties. The soil total C (STC), nitrate N (NO3−-N) and soil total N (STN) concentrations were the main factors that affected the leaf traits. Conclusions: Seasonal drought had a stronger effect on M. pauhoi seedling leaf traits than short-term N deposition, indicating that the interaction between seasonal drought and short-term N deposition may have an additive effecton M. pauhoi seedling growth in N-rich subtropical China.

scholarly journals Response of litter decomposition and the soil environment to one-year nitrogen addition in a Schrenk spruce forest in the Tianshan Mountains, China

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhaolong Ding ◽  
Xu Liu ◽  
Lu Gong ◽  
Xin Chen ◽  
Jingjing Zhao ◽  
...  
Keyword(s):  
Nitrogen Deposition ◽  
Litter Decomposition ◽  
Forest Ecosystems ◽  
N Deposition ◽  
Tianshan Mountains ◽  
Control Treatment ◽  
N Addition ◽  
Soil Environment ◽  
N Application ◽  
Positive Effect

AbstractHuman activities have increased the input of nitrogen (N) to forest ecosystems and have greatly affected litter decomposition and the soil environment. But differences in forests with different nitrogen deposition backgrounds. To better understand the response of litter decomposition and soil environment of N-limited forest to nitrogen deposition. We established an in situ experiment to simulate the effects of N deposition on soil and litter ecosystem processes in a Picea schrenkiana forest in the Tianshan Mountains, China. This study included four N treatments: control (no N addition), low N addition (LN: 5 kg N ha−1 a−1), medium N addition (MN: 10 kg N ha−1 a−1) and high N addition (HN: 20 kg N ha−1 a−1). Our results showed that N addition had a significant effect on litter decomposition and the soil environment. Litter mass loss in the LN treatment and in the MN treatment was significantly higher than that in the control treatment. In contrast, the amount of litter lost in the HN treatment was significantly lower than the other treatments. N application inhibited the degradation of lignin but promoted the breakdown of cellulose. The carbon (C), N, and phosphorus (P) contents of litter did not differ significantly among the treatments, but LN promoted the release of C and P. Our results also showed that soil pH decreased with increasing nitrogen application rates, while soil enzyme activity showed the opposite trend. In addition, the results of redundancy analysis (RDA) and correlation analyses showed that the soil environment was closely related to litter decomposition. Soil enzymes had a positive effect on litter decomposition rates, and N addition amplified these correlations. Our study confirmed that N application had effects on litter decomposition and the soil environment in a N-limited P. schrenkiana forest. LN had a strong positive effect on litter decomposition and the soil environment, while HN was significantly negative. Therefore, increased N deposition may have a negative effect on material cycling of similar forest ecosystems in the near future.

scholarly journals Nitrogen Additions Retard Nutrient Release from Two Contrasting Foliar Litters in a Subtropical Forest, Southwest China

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 377 ◽  
Author(s):  
Liyan Zhuang ◽  
Qun Liu ◽  
Ziyi Liang ◽  
Chengming You ◽  
Bo Tan ◽  
...  
Keyword(s):  
Litter Decomposition ◽  
Critical Role ◽  
C:N Ratio ◽  
Terrestrial Ecosystems ◽  
N Deposition ◽  
Decay Rates ◽  
N Addition ◽  
K Value ◽  
P Release ◽  
N Additions

Litter decomposition plays a critical role in regulating biogeochemical cycles in terrestrial ecosystems and is profoundly impacted by increasing atmospheric nitrogen (N) deposition. Here, a N manipulation experiment was conducted to explore the effects of N additions (0 kg N ha−1 yr−1, 20 kg N ha−1 yr−1 and 40 kg N ha−1 yr−1) on decay rates and nutrients release of two contrasting species, the evergreen and nutrient-poor Michelia wilsonii and the deciduous and nutrient-rich Camptotheca acuminata, using a litterbag approach at the western edge of the Sichuan Basin of China. The decay rate and the mineralization of N and phosphorus (P) was faster in nutrient-rich C. acuminata litter than in nutrient-poor M. wilsonii litter, regardless of N regimes. N additions tended to decrease the decay constant (k value) in M. wilsonii litter, but had no effect on C. acuminata litter. N additions had no significant effects on carbon (C) release of both litter types. N additions showed negative effects on N and P release of M. wilsonii litter, particularly in the late decomposition stage. Moreover, for C. acuminata litter, N additions did not affect N release, but retarded P release in the late stage. N additions did not affect the C:N ratio in both litter types. However, N additions—especially high-N addition treatments—tended to reduce C:P and N:P ratios in both species. The effect of N addition on N and P remaining was stronger in M. wilsonii litter than in C. acuminata litter. The results of this study indicate that N additions retarded the nutrients release of two foliar litters. Thus, rising N deposition might favor the retention of N and P via litter decomposition in this specific area experiencing significant N deposition.

Radiative forcing of forest biomass production and use under different thinning regimes and initial age structures of a Norway spruce forest landscape

2020 ◽  
Vol 50 (6) ◽  
pp. 523-532
Author(s):  
Tarit Kumar Baul ◽  
Ashraful Alam ◽  
Harri Strandman ◽  
Jyri Seppälä ◽  
Heli Peltola ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Norway Spruce ◽  
Biomass Production ◽  
Age Structure ◽  
Radiative Forcing ◽  
Forest Biomass ◽  
Forest Landscape ◽  
Middle Aged ◽  
Use Efficiency ◽  
Age Structures

We studied how different thinning regimes and initial age structures of a Norway spruce (Picea abies (L.) Karst.) forest landscape affect the radiative forcing of forest biomass production and use. We considered the effects of forest carbon sequestration, substitution of materials and fossil fuels with forest biomass, and timber use efficiency. The initial age structures of our hypothetical forest landscapes in the middle boreal zone in Finland were young, middle-aged, and mature. Forest landscapes were thinned using either the current thinning recommendations (baseline) or maintaining 20% higher or 20% lower stocking over the 80-year study period. We employed forest ecosystem model simulations together with a life cycle assessment tool. The highest carbon sequestration was obtained by maintaining higher stocking in the landscapes. The initially middle-aged and mature age structures resulted in the strongest cooling of the climate in the first three decades of the simulation, but the highest cooling was found in the young age structure. However, radiative forcing was less sensitive to the thinning than to the substitution or timber use efficiency. Our results indicate that modeled climate impacts are affected by both initial age structure and forest management, which should be considered when generalizing the climate change mitigation potential of forests and forestry.

Water-use efficiency of four native trees under CO2enrichment and N addition in subtropical model forest ecosystems

2014 ◽  
Vol 8 (4) ◽  
pp. 411-419 ◽  
Author(s):  
Yiyong Li ◽  
Juxiu Liu ◽  
Genyun Chen ◽  
Guoyi Zhou ◽  
Wenjuan Huang ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Forest Ecosystems ◽  
N Addition ◽  
Native Trees ◽  
Use Efficiency

scholarly journals Initial shifts in nitrogen impact on ecosystem carbon fluxes in an alpine meadow: patterns and causes

2017 ◽  
Vol 14 (17) ◽  
pp. 3947-3956 ◽  
Author(s):  
Bing Song ◽  
Jian Sun ◽  
Qingping Zhou ◽  
Ning Zong ◽  
Linghao Li ◽  
...  
Keyword(s):  
Alpine Meadow ◽  
Microbial Respiration ◽  
Ecosystem Respiration ◽  
C Sequestration ◽  
N Deposition ◽  
N Saturation ◽  
N Addition ◽  
Soil Microbial ◽  
Soil Microbial Respiration ◽  
Plant Respiration

Abstract. Increases in nitrogen (N) deposition can greatly stimulate ecosystem net carbon (C) sequestration through positive N-induced effects on plant productivity. However, how net ecosystem CO2 exchange (NEE) and its components respond to different N addition rates remains unclear. Using an N addition gradient experiment (six levels: 0, 2, 4, 8, 16, 32 gN m−2 yr−1) in an alpine meadow on the Qinghai–Tibetan Plateau, we explored the responses of different ecosystem C fluxes to an N addition gradient and revealed mechanisms underlying the dynamic responses. Results showed that NEE, ecosystem respiration (ER), and gross ecosystem production (GEP) all increased linearly with N addition rates in the first year of treatment but shifted to N saturation responses in the second year with the highest NEE (−7.77 ± 0.48 µmol m−2 s−1) occurring under an N addition rate of 8 gN m−2 yr−1. The saturation responses of NEE and GEP were caused by N-induced accumulation of standing litter, which limited light availability for plant growth under high N addition. The saturation response of ER was mainly due to an N-induced saturation response of aboveground plant respiration and decreasing soil microbial respiration along the N addition gradient, while decreases in soil microbial respiration under high N addition were caused by N-induced reductions in soil pH. We also found that various components of ER, including aboveground plant respiration, soil respiration, root respiration, and microbial respiration, responded differentially to the N addition gradient. These results reveal temporal dynamics of N impacts and the rapid shift in ecosystem C fluxes from N limitation to N saturation. Our findings bring evidence of short-term initial shifts in responses of ecosystem C fluxes to increases in N deposition, which should be considered when predicting long-term changes in ecosystem net C sequestration.

scholarly journals Nitrogen Deposition to and Cycling in a Deciduous Forest

2001 ◽  
Vol 1 ◽  
pp. 245-254 ◽  
Author(s):  
Sara C. Pryor ◽  
Rebecca J. Barthelmie ◽  
Margaret Carreiro ◽  
Melissa L. Davis ◽  
Anne Hartley ◽  
...  
Keyword(s):  
Deciduous Forest ◽  
C:N Ratio ◽  
Growing Season ◽  
C Sequestration ◽  
N Deposition ◽  
Net N Mineralization ◽  
Canopy Exchange ◽  
Canopy Uptake ◽  
Potential Perturbation ◽  
N Flux

The project described here seeks to answer questions regarding the role increased nitrogen (N) deposition is playing in enhanced carbon (C) sequestration in temperate mid-latitude forests, using detailed measurements from an AmeriFlux tower in southern Indiana (Morgan-Monroe State Forest, or MMSF). The measurements indicate an average atmosphere-surface N flux of approximately 6 mg-N m-2day-1during the 2000 growing season, with approximately 40% coming from dry deposition of ammonia (NH3), nitric acid (HNO3), and particle-bound N. Wet deposition and throughfall measurements indicate significant canopy uptake of N (particularly NH4+) at the site, leading to a net canopy exchange (NCE) of –6 kg-N ha-1for the growing season. These data are used in combination with data on the aboveground C:N ratio, litterfall flux, and soil net N mineralization rates to indicate the level of potential perturbation of C sequestration at this site.

scholarly journals Growth Responses of Agropyron Mongolicum Keng to Nitrogen Addition Is Linked to Root Morphological Traits and Nitrogen-Use Efficiency.

2021 ◽  
Author(s):  
Aiyun XU ◽  
Xing Wang ◽  
Xiaojia Wang ◽  
Dongmei Xu ◽  
Bing Cao
Keyword(s):  
Native Species ◽  
Morphological Traits ◽  
Growth Response ◽  
N Deposition ◽  
N Use Efficiency ◽  
N Addition ◽  
Desert Grassland ◽  
Growth Responses ◽  
Use Efficiency ◽  
N Use

Abstract Background and aimsNitrogen (N) is the primary limiting factors for plant growth and development, and increasingly N deposition alters plant composition, consequently affecting ecosystem function have been widely acknowledged. However, the effects of N fertilization on native species in desert grassland ecosystem and underlying mechanisms of these effects are still poorly understood. This study was conducted to examine the growth response of Agropyron mongolicum keng to N addition and potential mechanisms underlying this effect.MethodsA.mongolicum Keng was subjected to five N addition levels (0, 0.8,1.6, 2.4, and 4.0g N m−2 yr−1) for six months under greenhouse conditions. A combination of linear and structural equation modelling was used to examine growth response of A.mongolicum Keng to N addition and test whether its response related to root morphological traits and N-use efficiency.ResultsGrowth responses of A. mongolicum Keng to increasing N addition appeared a unimodal-shaped with a N saturation threshold at 3.2g N m-1 yr-1. Its response closely related to the root surface area, volume, length, and forks number, N uptake and utilization efficiency. Besides, N-induced changes in soil available nutrient have an indirect impaction biomass of A. mongolicum Keng via regulation of root morphological traits and N-use efficiency.ConclusionsThese findings highlight the sensibility of A. mongolicum Keng to N addition and the importance of root morphological traits and N-use efficiency in affecting biomass. Therefore, these can provide important insights into potential changes of native species survival and development in nutrient-limited desert grassland caused by N deposition.

scholarly journals Long-term nitrogen addition decreases carbon leaching in nitrogen-rich forest ecosystems

2013 ◽  
Vol 10 (1) ◽  
pp. 1451-1481 ◽  
Author(s):  
X. Lu ◽  
F. S. Gilliam ◽  
G. Yu ◽  
L. Li ◽  
Q. Mao ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Critical Role ◽  
C Sequestration ◽  
Nitrogen Addition ◽  
N Deposition ◽  
N Addition ◽  
Soil C ◽  
Rooting Zone ◽  
C Cycle

Abstract. Dissolved organic carbon (DOC) plays a critical role in the carbon (C) cycle of forest soils, and has been recently connected with global increases in nitrogen (N) deposition. Most studies on effects of elevated N deposition on DOC have been carried out in N-limited temperate regions, with far fewer data available from N-rich ecosystems, especially in the context of chronically elevated N deposition. Furthermore, mechanisms for excess N-induced changes of DOC dynamics have been suggested to be different between the two kinds of ecosystems, because of the different ecosystem N status. The purpose of this study was to experimentally examine how long-term N addition affects DOC dynamics below the primary rooting zones (the upper 20 cm soils) in typically N-rich lowland tropical forests. We have a primary assumption that long-term continuous N addition minimally affects DOC concentrations and effluxes in N-rich tropical forests. Experimental N addition was administered at the following levels: 0, 50, 100 and 150 kg N ha−1 yr−1, respectively. Results showed that seven years of N addition significantly decreased DOC concentrations in soil solution, and chemo-physical controls (solution acidity change and soil sorption) rather than biological controls may mainly account for the decreases, in contrast to other forests. We further found that N addition greatly decreased annual DOC effluxes from the primary rooting zone and increased water-extractable DOC in soils. Our results suggest that long-term N deposition could increase soil C sequestration in the upper soils by decreasing DOC efflux from that layer in N-rich ecosystems, a novel mechanism for continued accumulation of soil C in old-growth forests.

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