Ecological stoichiometry examines the balance of elements like carbon, nitrogen, and phosphorus in ecological interactions and processes. A key study found that removing planktivorous fish from an eutrophic lake and allowing zooplankton populations like Daphnia to increase altered nutrient cycling. This increased the relative availability of nitrogen over phosphorus, countering the original low nitrogen to phosphorus input ratio and decreasing cyanobacteria dominance. The results supported theories linking nutrient ratios, growth rates, and food web structure based on organisms' nucleic acid and ribosomal RNA composition.
The nitrogen cycle is composed of four steps: nitrogen fixation, nitrification. at there ammonification, is an important process in the nitrogen cycle and is, basically, the process of decomposition with production of ammonia or ammonium compounds, especially by the action of bacteria on organic matter.
Biological nitrogen fixation (BNF) can be defined as the conversion of atmospheric dinitrogen (N2) to ammonia (NH3) under the combined action of biological and chemical activities
biological nitrogen fixation, which is carried out by diazotrophs, has been dealt with in this slideshare. it involves the mechanism involved and various factors involved therein.
The nitrogen cycle is composed of four steps: nitrogen fixation, nitrification. at there ammonification, is an important process in the nitrogen cycle and is, basically, the process of decomposition with production of ammonia or ammonium compounds, especially by the action of bacteria on organic matter.
Biological nitrogen fixation (BNF) can be defined as the conversion of atmospheric dinitrogen (N2) to ammonia (NH3) under the combined action of biological and chemical activities
biological nitrogen fixation, which is carried out by diazotrophs, has been dealt with in this slideshare. it involves the mechanism involved and various factors involved therein.
REDOX POTENTIAL MEASUREMENT AND ITS APPLICATION IN SOIL FERTILITYKARTHIKEYANB30
What is mean redox reaction, How to measure redox condition in soil, Application of redox potential in nutrient management, Kinetics of pH, EC, Nutrients in soil
Biochar is charcoal used as a soil amendment.
Biochar is a stable solid, rich in carbon, and can endure in soil for thousands of years.Like most charcoal, biochar is made from biomass via pyrolysis. Biochar is under investigation as an approach to carbon sequestration.Biochar thus has the potential to help mitigate climate change via carbon sequestration. Independently, biochar can increase soil fertility of acidic soils (low pH soils), increase agricultural productivity, and provide protection against some foliar and soil-borne diseases.
Introduction,Definition, Cycling elements, Types of biogeochemical cycle- Gaseous cycle and sedimentary cycle Nitrogen cycle, steps of Nitrogen cycle- Nitrogen fixation, Nitrification, Assimilation Ammonification, and Denitrification and ecological function of nitrogen, use of nitrogen cycle phosphorus cycle, steps of phosphorus cycle, biological functions of phosphorus cycle and other functions of phosphorus and conclusion
A series of PowerPoint slides that will be useful when introducing students to the study of biogeochemistry: definitions, four main elemental cycles, isotopic techniques.
“Any living organism supplying plant nutrients directly or indirectly is regarded as biofertilizer. They are not synthetically manufactured in factory.”
Concept of Participatory Resource Appraisal, Role of community in resource appraisal is also discussed. Impact of Participatory Resource Appraisal is also mentioned
REDOX POTENTIAL MEASUREMENT AND ITS APPLICATION IN SOIL FERTILITYKARTHIKEYANB30
What is mean redox reaction, How to measure redox condition in soil, Application of redox potential in nutrient management, Kinetics of pH, EC, Nutrients in soil
Biochar is charcoal used as a soil amendment.
Biochar is a stable solid, rich in carbon, and can endure in soil for thousands of years.Like most charcoal, biochar is made from biomass via pyrolysis. Biochar is under investigation as an approach to carbon sequestration.Biochar thus has the potential to help mitigate climate change via carbon sequestration. Independently, biochar can increase soil fertility of acidic soils (low pH soils), increase agricultural productivity, and provide protection against some foliar and soil-borne diseases.
Introduction,Definition, Cycling elements, Types of biogeochemical cycle- Gaseous cycle and sedimentary cycle Nitrogen cycle, steps of Nitrogen cycle- Nitrogen fixation, Nitrification, Assimilation Ammonification, and Denitrification and ecological function of nitrogen, use of nitrogen cycle phosphorus cycle, steps of phosphorus cycle, biological functions of phosphorus cycle and other functions of phosphorus and conclusion
A series of PowerPoint slides that will be useful when introducing students to the study of biogeochemistry: definitions, four main elemental cycles, isotopic techniques.
“Any living organism supplying plant nutrients directly or indirectly is regarded as biofertilizer. They are not synthetically manufactured in factory.”
Concept of Participatory Resource Appraisal, Role of community in resource appraisal is also discussed. Impact of Participatory Resource Appraisal is also mentioned
Pol Tarrats presentation on Sefs9 - Geneva 2015
CLAM project - Global Change in Mountain Lakes
"Study and understand the present to explain the past"
ABSTRACT: Grab samples from Enol Lake (1080 m.a.s.l., Picos de Europa National Park, Spain) were collected to evaluate the chironomid community composition, structure and spatial and temporal variability. We obtained 3 replicate samples at 4, 8, 12, 16 and 20 m water depth four times per year (May, July, September and November) in two consecutive years (2013 and 2014), with a total of 120 samples analyzed. A total of 19 taxa were identified, although the dominant taxa in all samples were Paratanytarsus, Chironomus, Tanytarsus and Procladius choreus. Chironomusand Stictochironomus taxa abundance increased with depth while the more abundant taxa in the littoral were Paratanytarsus,Endochironomus and Corynoneura. Seasonal changes concern many chironomid taxa, although it is more relevant in the case ofCorynoneura, Tanytarsus and Procladius. Spatial changes are mostly related to the presence of macrophytes and algae, especially Chara, as chironomid composition and abundance are very different in samples from macrophyte-rich and poor areas.
Winter is considered a dormancy period for phytoplankton, mainly due to the absence of light an to low temperatures. But is it? We have found diverse phytoplankton communities under the ice and their fatty acids reveal they are excellent quality food for zooplankton.
Zooplanktonic Diversity and Trophic Status of Pashupatinath Pond in Relation ...IOSR Journals
Present investigation were carried out to physico chemical characterstics and trophic status of
Pashupatinath pond Mandsour (M.P.).water sample were collected seasonal basis for a period of December
2008 to September 2010 using plastic container .standard procedure were followed during collection
,preservation and analysis of water sample for various physicochemical and biological parameter .
The water quality is remained moderately alkaline PH (8.11) while electrical conductivity (0.2176 ms/cm), TDS
(187ppm) chloride (22.123ppm), Hardness(139.166ppm) and alkalinity (75.33ppm) show low mean value
.Average dissolve oxygen levels were at (7.771 ppm) ,while average nitrate and phosphate The water remained
modertly alkaline PH (7.95) while electrical conductance (0.2165ms/cm),TDS (153.66ppm)chloride (22.83ppm)
hardness (138.66ppm )and alkalinity (62.166 ppm) showed low mean values .Average dissolved oxygen level
were at (7.58 ppm ) while average nitrate and phosphate level were (0.2126ppm) and (0.5868 ppm) respectely
.On the basis of water quality parameter .Mirzapur dam was found to be oligotrophic. A low density of
Zooplankton were also observed during the study period
- Describe why measuring the response of plant productivity (NPP) to.pdfRahul04August
- Describe why measuring the response of plant productivity (NPP) to independent N and P
additions is a better predictor of nutrient limitation than measuring the N:P stoichiometry of
leaves ?
- Soil minerals have electrostatic charge. The charge is
- The ideal C/N ratio of microbe food (plant litter or soil organic matter) is greater than the C/N
ratio of microbial biomass. Why?
Solution
1.Foliar nutrients, especially nitrogen and phosphorus concentrations ([N] and [P]) and their
ratio, have been used widely as indicators of plant nutritional status and have been linked directly
to nutrient limitation of NPP. In tropical systems, however, a high number of confounding
factors can limit the ability to predict nutrient limitation —as defined mechanistically by NPP
responses to fertilization— based on the stoichiometric signal of the plant community.
Also.consistent with NPP responses to fertilization, there will be no changes in community-wide
foliar [N] and [P].life history traits can become more important controls over tissue nutrient
concentrations and the stoichiometric signal of the plant community.
2.Physical adsorption.
Electric charges on soil colloids arise from principally three sources:
from isomorphous substitution of one ion by another of different valency within the clay mineral
structure. This gives rise to mainly negative charges. The charges are permanent and do not
change with change in pH of the external solution.
from ionisation of OH groups attached to the Al, Si, Fe at the edges of clay minerals. The
charges created by this process are negative, zero or positive depending on the pH.
from ionisation of - NH2, - OH and - COOH functional groups in the organic matter of soils.
This too gives rise to positive, neutral and negative charges depending on the pH.
3.Carbon to Nitrogen ratio (C:N) is a ratio of the mass of carbon to the mass of nitrogen in a
substance. Because soil microorganisms burn carbon as a source of energy, not all of the carbon
a soil microorganism eats remains in its body; a certain amount is lost as carbon dioxide during
respiration. To acquire the carbon and nitrogen a soil microorganism needs to stay alive (body
maintenance + energy) it needs a diet with a C:N ratio near 24:1, with 16 parts of carbon used for
energy and eight parts for maintenance. Since wheat straw contains a greater proportion of
carbon to nitrogen than the 24:1 perfectly balanced diet soil microorganisms require, the
microbes will have to find additional nitrogen to go with the excess carbon to consume the wheat
straw. This additional nitrogen will have to come from any excess nitrogen available in the soil.
As soil microorganisms tie up excess nitrogen (immobilization), this situation could create a
deficit of nitrogen in the soil until some of them die, decompose, and release nitrogen
(mineralization) contained in their bodies, or some other source of nitrogen becomes available in
the soil.up excess nitrogen (immobilization), this si.
Andersen et al. 2004: Stoichiometry and DynamicsNoam Ross
This presentation by Lauren Yamane was given to the ECL290 Course on Ecological Stoichiometry on November 13, 2012. It summarizes Andersen et al. (2004)
Modifying River-Floodplain Systems: A Historical and Ecological PerspectiveNoam Ross
This presentation made 9/14 at the UC Davis REACH IGERT Floodplains workshop, by Jaime Ashander, Kelly Gravuer, Megan Kelso, Mary E. Mendoza, Noam Ross
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
2. Why is stoichiometry important?
• Conservation of mass and energy
• Growth is limited by nutrients, that are required
in fairly strict ratios
• Ecosystems have a finite amount of elements and
inputs/outputs
• Without limiting nutrients, energy, or
space, theoretical population dynamics may give
infinite growth (implicitly included in carrying
capacity)
3. • Humans have
much more C,N,P
as a fraction of
total mass than
occurs in the earth
as a whole
• Must be
preferentially
accumulating
these elements
Sterner and Elser, 2002
5. N vs. P
• P available in rock form and decreases as
ecosystem age
• N can be fixed by organisms from the atmosphere
to inorganic bio-available forms (but this is
energetically expensive and requires lots of P as
ATP)
• Aquatic ecosystems often thought to be P limited
because N can be brought in via fixation. Also
affected by anthropogenic N inputs (runoff, dep)
Walker and Syers 1976; Vitousek et al. 2010
6. N, P, and co- limitation
Large purple bars
suggests co-
limitation of N
and P. This could
be supported by
re-allocation of
one nutrient to
get another to
optimize growth
Elser et al., Ecology Letters, 2008
8. Background info: Redfield Ratios
• Phytomass displays an average C:N:P of
106:16:1
• This is similar to the C:N:P of dissolved
matter in the ocean
Redfield, American Naturalist, 1958
9. NO3- from PO43-
Oceaninferred and CNP deviations
N* - processes
Mean Phytoplankton
106:16:1
1:16 P:N line
N* = NO3- – 16PO43- + 2.9 Gruber and Sarmiento 199
10. N/P
Tropical Temperate
Leaf litter (reg) 43:1 12:1
Leaf: 43:1 25:1
Leaf litter: 63:1 27:1
All forest microbes 9:1
Fungi 15:1
Bacteria 7:1
Enzymes 1:1
McGroddy et al. 2004; Townsend
et al. ; Cleveland et al. 2007;
Reiners 1986; Sinsabaugh et al.;
12. Pelagic CNP in eutrophic lake with food
web manipulation
• Q: How do tropic dynamics and biogeochemistry
interact in regulating lake ecosystem dynamics
during a whole-lake food-web manipulation?
• HYP: elimination of planktivorous fishes would
result in a pelagic food web in which P-rich
zooplankton (for example, Daphnia) would have a
greatly enhanced role in regulating internal
nutrient availability and would differentially
increase the availability of N relative to P.
Elser et al. 2000 Ecosystems
13. Responses to Pike
• + Pike
• 3 yrs later:
- minnows
• 4 yrs later:
+ cladoceran
Daphnia
- zooplankton N:P
- seston C:P
+ DON and DOP
Elser et al. 2000 Ecosystems
14. N fixation
• Low external N/P ratio
• Internal processes driven
by food-web changes
fixed enough N relative to
P in the early season to
allow phytoplankton to
grow similarly to 25 years
previously
• Then cyanobacteria
crashed
• Suggests threshold N/P
ratio for N fixation to be
energetically favorable
Elser et al. 2000 Ecosystems
15. 5 aspects of stoichiometric effects
• Zooplankton became more P rich (lower C:P and N:P ratio)
• The importance of zooplankton as a nutrient pool in the
water column greatly increased
• Increased zooplankton biomass increased overal dissolved
nutrient availability (more for N than P). This caused shift
away from N-fixing cyanobacteria
• Seston C:P and N:P ratios were low, indicating relatively
rapid groth rates of remaining phytoplankton biomass.
Decreased phytoplankton bioass reflected less of the
limiting nutrient P
• Sedimentation appears to have been altered by food web
manipulation
Elser et al. 2000 Ecosystems
16. Conclusions
• Consumer-driven nutrient cycling processes
appeared to have increased N:P ratio in the
available nutrient supply.
• This should result in decreased dominance of
cyanobacteria in phytoplankton community
• Introduction of piscivorous pike and elimination
of planktivorous fish generated low N:P sink
(Daphnia zooplankton community) counteracted
the low N:P source of nutrients entering the
lake, drastically altering the response of the lake
Elser et al. 2000 Ecosystems
17. Modeling implications
• Eutrophic lakes are characterized by alternative stable
states
• These dynamics are consistent with stoichiometric models
of grazer-algae interactions
• These models predict the existence of intrinsic high grazer
and grazer-free stable states under eutrophic conditions
• Nutrient loading ,tropic cascades and stoichiometric
theories provide a fundamental understanding of eutrophic
lake dynamics
• Our ability to make specific predictions of the occurrence
and intensity of cyanobacteria biomass may be limited by
the nonlinear mechanisms underpinning the nutrient-
phytoplankton-zooplankton systems
Elser et al. 2000 Ecosystems
18. Biological stoichiometry
• Biological stoichiometry: coupling the first
laws of thermodynamics; evolution by natural
selection; and central dogma of molecular
biology
• Roots: optimal foaging; resource ratio
competition theory; Redfield ratio; nutrient
use efficiency
Elser et al. 2000 Ecology Letters
19. Biological stoichiometry from genes to
ecosystems
• Q: What determines the C:N:P of living
biomass?
• HYP: a connection between growth rate and
C:N:P stoichiometry based on rRNA allocation
and the organization of ribosomal genes in
diverse biota
Elser et al. 2000 Ecology Letters
20. Autotroph N:P rules of thumb
• Biomass N:P tracks N:P of the nutrient supply
• At fixed supply rate of nutrient X, biomass C:X
increases as light intensity and/or pCO2
increase
• Under concentrations of X-limited
growth, biomass C:X increases steeply as
realized specific growth rate declines
• High variation of C:N:P in base of food web
Elser et al. 2000 Ecology Letters
21. Growth rate and P relationships
• Organisms with high max specific growth rate
have high [RNA]
• RNA makes up 50-60% of the ribosome, which
promotes cell growth
• RNA is 10% P by weight
• P-rich, low N:P is a signature of rapid growth
and is a cellular necessity
• Most variation occurs in chromosomal rDNA
copy number
Elser et al. 2000 Ecology Letters
22. Growth Rate Hypothesis
• rRNA is needed for
protein synthesis;
rRNA is ~80% of all
RNA in organisms
• RNA has a relatively
low N/P
• Thus, growth rate is
limited by P and
N/P variation is
largely driven by
investment in rRNA
Sterner and Elser, 2002
23. Molecular genetics of food web
dynamics hypothesis
• Goal: generate functionally realistic model of
ecological dynamics informed by modern
genetic understanding
• Evolution of growth rate related to RNA
allocation and organism P content/CNP stoich
• HYP: variation in the relative abundance of
high growth rate, low C:P and N:P consumers
with high rDNA should be higher in systems
with good quality (low C:N and C:P food).
Elser et al. 2000 Ecology Letters
24. Resource
Ratio
Theory
Miller, American Naturalist 2005
25. Questions and discussion:
1. How might results differ if the lake were not eutrophic?
2. How do terrestrial and lake ecosystems differ, and what
are the problems?
3. In what situations is it worth incorporating nutrient
dynamics and stoichiometry, and when might it be
unneccessarily complicating the model?
4. Does Elser’s RNA hypotheses make sense when comparing
across global scales, like tropics vs. temperate?
Elser et al. 2000 Ecology Letters