scholarly journals Effects of nitrogen and phosphorus on the abundance and cell size of planktonic nanoflagellate communities

2013 ◽  
Vol 24 (4) ◽  
pp. 427-437
Author(s):  
Danielle Goeldner Pereira ◽  
Fábio Amodêo Lansac-Tôha ◽  
Gustavo Mayer Pauleto ◽  
Luis Mauricio Bini ◽  
Luiz Felipe Machado Velho
Keyword(s):  
Cell Size ◽  
Nutrient Enrichment ◽  
Nitrogen Addition ◽  
Nutrient Addition ◽  
Heterotrophic Nanoflagellates ◽  
Nitrogen And Phosphorus ◽  
Tropical Reservoir ◽  
Pigmented Nanoflagellates ◽  
Density And Biomass ◽  
Nitrogen And Phosphorus Enrichment

AIM: We experimentally investigated the effects of nutrients (Nitrogen and Phosphorus) enrichment on the density, biomass, and cell size of pigmented and heterotrophic plankton nanoflagellates communities. METHODS: The experiment was done in mesocosms in a tropical reservoir during a 19-day period. Four different treatments were carried out: Control (non-nutrient addition - C), phosphorus additions (P), nitrogen addition (N) and phosphorus + nitrogen addition (N + P). Each treatment was performed in triplicate, sorted randomly, thus giving a total of 12 experimental carboys, which were placed transversely in the middle of the reservoir. RESULTS: In general, pigmented and heterotrophic nanoflagellates fractions responded to nutrient addition, increasing densities and biomass values at the fertilized treatments. Opposed to expected, enriched treatments resulted in a slight decrease in mean cell size of the pigmented fraction. Moreover, in nutrient-rich treatments, pigmented nanoflagellates had higher relative abundance than in the control. CONCLUSIONS: Our results indicate that: i) the density and biomass of nanoflagellates responded to the nutrient enrichment, mainly when N and P were added together; ii) the pigmented and heterotrophic fractions showed distinct time responses to fertilization; iii) the growth of nanoflagellate community seems to be co-limited by N and P; iv) the nutrient enrichment led to a greater pigmented than heterotrophic fraction contribution; and v) among the analyzed variables, nanoflagellate densities seem to be more sensitive to changes in nutrient availability than biomass or mean cell size.

scholarly journals Long-Term Nutrient Enrichment of an Oligotroph-Dominated Wetland Increases Bacterial Diversity in Bulk Soils and Plant Rhizospheres

mSphere ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Regina B. Bledsoe ◽  
Carol Goodwillie ◽  
Ariane L. Peralta
Keyword(s):  
Bacterial Community ◽  
Bacterial Diversity ◽  
Community Composition ◽  
Nutrient Enrichment ◽  
Bacterial Communities ◽  
Nutrient Addition ◽  
Nitrogen And Phosphorus ◽  
The Core ◽  
Soil Bacterial

ABSTRACT In nutrient-limited conditions, plants rely on rhizosphere microbial members to facilitate nutrient acquisition, and in return, plants provide carbon resources to these root-associated microorganisms. However, atmospheric nutrient deposition can affect plant-microbe relationships by changing soil bacterial composition and by reducing cooperation between microbial taxa and plants. To examine how long-term nutrient addition shapes rhizosphere community composition, we compared traits associated with bacterial (fast-growing copiotrophs, slow-growing oligotrophs) and plant (C3 forb, C4 grass) communities residing in a nutrient-poor wetland ecosystem. Results revealed that oligotrophic taxa dominated soil bacterial communities and that fertilization increased the presence of oligotrophs in bulk and rhizosphere communities. Additionally, bacterial species diversity was greatest in fertilized soils, particularly in bulk soils. Nutrient enrichment (fertilized versus unfertilized) and plant association (bulk versus rhizosphere) determined bacterial community composition; bacterial community structure associated with plant functional group (grass versus forb) was similar within treatments but differed between fertilization treatments. The core forb microbiome consisted of 602 unique taxa, and the core grass microbiome consisted of 372 unique taxa. Forb rhizospheres were enriched in potentially disease-suppressive bacterial taxa, and grass rhizospheres were enriched in bacterial taxa associated with complex carbon decomposition. Results from this study demonstrate that fertilization serves as a strong environmental filter on the soil microbiome, which leads to distinct rhizosphere communities and can shift plant effects on the rhizosphere microbiome. These taxonomic shifts within plant rhizospheres could have implications for plant health and ecosystem functions associated with carbon and nitrogen cycling. IMPORTANCE Over the last century, humans have substantially altered nitrogen and phosphorus cycling. Use of synthetic fertilizer and burning of fossil fuels and biomass have increased nitrogen and phosphorus deposition, which results in unintended fertilization of historically low-nutrient ecosystems. With increased nutrient availability, plant biodiversity is expected to decline, and the abundance of copiotrophic taxa is anticipated to increase in bacterial communities. Here, we address how bacterial communities associated with different plant functional types (forb, grass) shift due to long-term nutrient enrichment. Unlike other studies, results revealed an increase in bacterial diversity, particularly of oligotrophic bacteria in fertilized plots. We observed that nutrient addition strongly determines forb and grass rhizosphere composition, which could indicate different metabolic preferences in the bacterial communities. This study highlights how long-term fertilization of oligotroph-dominated wetlands could alter diversity and metabolism of rhizosphere bacterial communities in unexpected ways.

Effects of nutrient enrichment on the colonization and decomposition of plant detritus by the microbiota of an arctic lake

1982 ◽  
Vol 28 (11) ◽  
pp. 1199-1205 ◽  
Author(s):  
Thomas W. Federle ◽  
Vicky L. McKinley ◽  
J. Robie Vestal
Keyword(s):  
Weight Loss ◽  
Nutrient Enrichment ◽  
Plant Litter ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Enrichment ◽  
Arctic Lake ◽  
Twofold Increase ◽  
Plant Detritus ◽  
Fresh Litter ◽  
Nitrogen And Phosphorus Enrichment

The effects of nitrogen and phosphorus enrichment on the colonization and decomposition of plant litter (Carex) by the microbiota of Toolik Lake, Alaska, were studied in microcosms. Added phosphorus resulted in a fourfold (p ≤ 0.01) increase in the levels of ATP associated with the microbiota on fresh litter, while nitrogen-plus-phosphorus enrichments resulted in a twofold increase in the ATP associated with the microbiota of fresh (p ≤ 0.01) or partially degraded (p ≤ 0.05) litter compared with controls. Neither nitrogen nor phosphorus enrichments, alone or together, significantly altered the observed weight loss of either fresh or partially degraded litter, although additional phosphorus was immobilized by the litter microbiota when available. Subsequent experiments demonstrated that the increase in ATP resulting from nutrient enrichment occurred when the microcosms were incubated in daylight but not in the dark, suggesting that nutrient enrichment primarily stimulated the photosynthetic component of the detrital community.

scholarly journals Effect of Short-Term Low-Nitrogen Addition on Carbon, Nitrogen and Phosphorus of Vegetation-Soil in Alpine Meadow

2021 ◽  
Vol 18 (20) ◽  
pp. 10998
Author(s):  
Zhen’an Yang ◽  
Wei Zhan ◽  
Lin Jiang ◽  
Huai Chen
Keyword(s):  
Alpine Meadow ◽  
Nitrogen Addition ◽  
Ammonium Nitrogen ◽  
N Deposition ◽  
Total Carbon ◽  
N Addition ◽  
Short Term ◽  
Nitrogen And Phosphorus ◽  
Soil Rhizosphere ◽  
And Function

As one of the nitrogen (N) limitation ecosystems, alpine meadows have significant effects on their structure and function. However, research on the response and linkage of vegetation-soil to short-term low-level N deposition with rhizosphere processes is scant. We conducted a four level N addition (0, 20, 40, and 80 kg N ha−1 y−1) field experiment in an alpine meadow on the Qinghai-Tibetan Plateau (QTP) from July 2014 to August 2016. We analyzed the community characteristics, vegetation (shoots and roots), total carbon (TC), nutrients, soil (rhizosphere and bulk) properties, and the linkage between vegetation and soil under different N addition rates. Our results showed that (i) N addition significantly increased and decreased the concentration of soil nitrate nitrogen (NO3−-N) and ammonium nitrogen, and the soil pH, respectively; (ii) there were significant correlations between soil (rhizosphere and bulk) NO3−-N and total nitrogen (TN), and root TN, and there was no strong correlation between plant and soil TC, TN and total phosphorus, and their stoichiometry under different N addition rates. The results suggest that short-term low-N addition affected the plant community, vegetation, and soil TC, TN, TP, and their stoichiometry insignificantly, and that the correlation between plant and soil TC, TN, and TP, and their stoichiometry were insignificant.

scholarly journals Laboratory study on the effects of nutrient enrichment on a phytoplankton population in Sawa Lake, Iraq

2008 ◽  
Vol 5 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Population Dynamics ◽  
Lake Water ◽  
Nutrient Enrichment ◽  
Cell Number ◽  
Shannon Index ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Population ◽  
Phytoplankton Cell ◽  
Nitrogen Phosphorus ◽  
Index Of Diversity

Nutrient enrichment of Sawa lake water was made using different nitrogen and phosphorus concentrations during autumn and spring at three stations. Different concentrations of nitrogen, phosphorus and N: P ratios were used to test variations in phytoplankton population dynamics. Nitrogen at a concentration of 25 µmole.l-1 and N: P ratio of 10:1 gave highest phytoplankton cell number at all stations and seasons. A total of 64 algal taxa dominated by Bacillariophyceae followed by Cyanophyceae and Chlorophyceae were identified. The values of Shannon index of diversity were more than one in the studied stations.

Nitrogen addition regulates tradeoff between root capture and foliar resorption of nitrogen and phosphorus in a subtropical pine plantation

Trees ◽  
2016 ◽  
Vol 31 (1) ◽  
pp. 77-91 ◽  
Author(s):  
Liang Kou ◽  
Huimin Wang ◽  
Wenlong Gao ◽  
Weiwei Chen ◽  
Hao Yang ◽  
...  
Keyword(s):  
Nitrogen Addition ◽  
Pine Plantation ◽  
Nitrogen And Phosphorus

scholarly journals Nitrogen and Phosphorus Budget for a Deep Tropical Reservoir of the Brazilian Savannah

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1205 ◽  
Author(s):  
Jackeline do S. B. Barbosa ◽  
Valéria R. Bellotto ◽  
Damiana B. da Silva ◽  
Thiago B. Lima
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Dynamics ◽  
Wastewater Treatment Plants ◽  
Organic Phosphorus ◽  
Inorganic Nitrogen ◽  
Nutrient Input ◽  
Nitrogen And Phosphorus ◽  
Tropical Reservoir ◽  
Artificial Lake ◽  
Total Organic Nitrogen

This research investigated the source and fate of different chemical species of N and P on a deep tropical urban reservoir, the artificial Lake Paranoá, located in the city of Brasilia (Brazil). To determine an N and P budget, nutrient input from the external load (four main tributaries and two wastewater treatment plants), internal load (from sediment) and nutrient output (from a downstream dam) were estimated empirically. Nutrient storage was evaluated in two compartments: water column and sediment. Nutrient input from the tributaries varied by season presenting higher loads in the wet season, especially N. Nutrient budgets in our study indicated that Lake Paranoá retained dissolved inorganic nitrogen (DIN), PO43−-P, total organic phosphorus (TOP) and exported total organic nitrogen (TON), both on a seasonal and annual scale. Surface sediment is the major storage compartment for both N and P. These results show the pressing need for action to reduce the P outcome charges, mainly, from the wastewater treatment plants. The data here presented contributes to the recognition of this situation and to a better comprehension of these nutrient dynamics, as well as an understanding of the behavior of tropical deep-water reservoirs. This can help to promote more effective management, providing a reference for other similar systems.

Evidence for a three-way trade-off between nitrogen and phosphorus competitive abilities and cell size in phytoplankton

Ecology ◽  
2011 ◽  
Vol 92 (11) ◽  
pp. 2085-2095 ◽  
Author(s):  
Kyle F. Edwards ◽  
Christopher A. Klausmeier ◽  
Elena Litchman
Keyword(s):  
Cell Size ◽  
Nitrogen And Phosphorus ◽  
Trade Off ◽  
Competitive Abilities
Sign in / Sign up

Export Citation Format

Share Document