if you want to remove an article from website contact us from top.

    which of the following describes the relationship between the amount of chlorophyll a in a water sample and the concentration of nitrogen in that sample?

    James

    Guys, does anyone know the answer?

    get which of the following describes the relationship between the amount of chlorophyll a in a water sample and the concentration of nitrogen in that sample? from EN Bilgi.

    Full article: Relationship of chlorophyll to phosphorus and nitrogen in nutrient

    (2017). Relationship of chlorophyll to phosphorus and nitrogen in nutrient-rich lakes. Inland Waters: Vol. 7, No. 4, pp. 385-400.

    Inland Waters

    Volume 7, 2017 - Issue 4

    17,895 Views 59

    CrossRef citations to date

    98 Altmetric Listen Articles

    Relationship of chlorophyll to phosphorus and nitrogen in nutrient-rich lakes

    Christopher T. Filstrup &John A. Downing

    Pages 385-400 | Published online: 09 Oct 2017

    Download citation

    https://doi.org/10.1080/20442041.2017.1375176

    CrossMark Full Article Figures & data References Supplemental Citations Metrics Licensing

    Reprints & Permissions

    PDF More Share Options

    Abstract

    Nitrogen (N) and phosphorus (P) commonly co-limit primary productivity in lakes, and chlorophyll (Chl-) is predicted to be greatest under high N, high P regimes. Because land use practices can alter N and P biogeochemical cycles in watersheds, it is unclear whether previously documented phytoplankton–nutrient relationships apply where landscapes are highly disturbed. Here, we analyzed a lake water quality database from an agricultural region to explore relationships among Chl-, total N (TN), and total P (TP) under extreme nutrient concentrations. Chl- was weakly related to TN when TP was ≤100 μg L−1 but displayed a stronger response to TN at higher TP. When TP exceeded 100 μg L−1, Chl- increased with increasing TN until reaching a TN threshold of ~3 mg L−1 and decreased thereafter, resulting in a high nutrient, low Chl- region that did not coincide with shifts in nutrient limitation, light availability, cellular Chl- content, phytoplankton composition, or zooplankton grazing pressure. Beyond the threshold, nitrate comprised most of TN and occurred with reduced dissolved organic matter (DOM). These observations suggest that photolysis of nitrate may produce reactive oxygen species that damage DOM and phytoplankton. Reduction in N loading at high P could therefore increase Chl- and decrease water clarity, resulting in an apparent worsening of water quality. Our data suggest that monitoring Chl- or Secchi depth may fail to indicate water quality degradation by extreme nutrient concentrations. These findings highlight how extreme nutrient regimes in lakes can produce novel relationships between phytoplankton and nutrients.

    Keywords:

    chlorophylleutrophicationlakesnitratenitrogenphosphorus

    Previous article Next article

    Introduction

    Current debate regarding nutrient management strategies to mitigate cultural eutrophication in lakes (e.g., Schindler et al. 2008, Scott and McCarthy 2010, Paerl et al. 2016, Schindler et al. 2016) warrants further study of phytoplankton–nutrient relationships. Early empirical studies of these relationships focused largely on phosphorus (P) because it was demonstrated to limit primary productivity in most lakes (Vollenweider 1968, Edmondson 1970, Schindler 1977). In temperate lakes, chlorophyll (Chl-) could be predicted as a positive log-linear function of total P (TP; Sakamoto 1966, Dillon and Rigler 1974, Jones and Bachmann 1976), thereby supporting P-limitation of primary productivity in lakes. Although log-linear models nicely predicted Chl- from TP in some lakes or regions, they tended to over-predict Chl- at high TP across large TP gradients using global datasets, resulting in Chl-–TP relationships better described as sigmoidal functions on log-transformed scales (McCauley et al. 1989). Although Chl- response to TP in individual lakes may differ from global empirical models (Smith and Shapiro 1981), the upper Chl- threshold to increasing TP suggested that another resource, such as nitrogen (N) or light, becomes limiting under high TP. While early whole ecosystem nutrient manipulations focused on oligotrophic lakes, where P-limitation was likely, phytoplankton biomass may commonly be limited by multiple nutrients in more productive lakes, especially over shorter temporal scales (see Sterner 2008).

    The influences of N or N:P ratios on phytoplankton biomass are well established, and current evidence strongly supports N and P co-limitation of primary productivity in most lakes and synergistic responses of phytoplankton to dual (N+P) nutrient enrichment (Elser et al. 2007, Allgeier et al. 2011, Bracken et al. 2015). In addition to Chl-–TP relationships, Sakamoto (1966) observed a strong log-linear relationship between Chl- and total N (TN) in Japanese lakes, where deviations from these relationships were hypothesized to result from changing nutrient supply ratios (i.e., N:P). Subsequent studies found that either TN or TN:TP ratios, in addition to TP, improved predictive relationships for Chl- across large N:P gradients (Smith 1982, Canfield 1983). TN:TP ratios can influence parameter estimates (i.e., slope and intercept) of log-linear relationships between Chl- and either TN or TP, despite Chl- being well correlated to individual nutrients across the entire TN:TP gradient (Prairie et al. 1989). Within a classification and regression tree framework, TN:TP ratios were often selected as an important factor in classifying lakes to improve Chl- predictions from TP (e.g., Yuan and Pollard 2014). In regions where N-limitation occurs, Chl- may show smaller responses to TP changes, however, and models including TN only may better predict Chl- where N-limitation is common (Smith and Shapiro 1981, Jones et al. 1989).

    N and P cycles can be coupled in lakes and streams (Finlay et al. 2013, Gibson et al. 2015), but human activities within watersheds may alter natural biogeochemical cycles. Agricultural practices such as fertilizer amendments or manure application not only contribute to increased N loads in receiving streams but can also cause shifts in the dissolved N pool (Howarth et al. 1996, Stanley and Maxted 2008). Eutrophic lakes can have low TN:TP compared to lakes in watersheds with natural land cover, although ratios depend on the type of agriculture (Downing and McCauley 1992). While lakes in regions with large-scale animal agriculture can have low TN:TP, lakes in regions dominated by row-crops commonly have high TN:TP (Arbuckle and Downing 2001). For example, high TN:TP loads from receiving streams in agricultural regions can maintain strict P-limitation of primary productivity (Vanni et al. 2011), whereas systems may be driven to N-limitation in livestock production regions. Additionally, watershed permeability and climate interact with land use and land cover to modify the effect of agricultural practices on lake nutrients (Fraterrigo and Downing 2008, Hayes et al. 2015). Because agricultural practices may modify N and P biogeochemical cycles, empirical relationships between phytoplankton and nutrients developed from regions with more diverse landscape characteristics may not apply to intense agricultural regions.

    Source : www.tandfonline.com

    bio tests Flashcards

    Study with Quizlet and memorize flashcards terms like Which of the following correctly shows the order in which protein X moves through the cell?, All of the following cell components are found in prokaryotic cells EXCEPT, Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move substances across their membranes. Which of the following statements describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions? and more.

    bio tests

    Which of the following correctly shows the order in which protein X moves through the cell?

    Click card to see definition 👆

    Endoplasmic reticulum→Golgi apparatus→lysosomes

    Click again to see term 👆

    All of the following cell components are found in prokaryotic cells EXCEPT

    Click card to see definition 👆

    nuclear envelope

    Click again to see term 👆

    1/63 Created by kristina_aleksanyan

    Terms in this set (63)

    Which of the following correctly shows the order in which protein X moves through the cell?

    Endoplasmic reticulum→Golgi apparatus→lysosomes

    All of the following cell components are found in prokaryotic cells EXCEPT

    nuclear envelope

    Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move substances across their membranes.

    Which of the following statements describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions?

    They have highly folded membranes.

    Which of the following components of the cell membrane is responsible for active transport?

    Protein

    Based on the information presented, which of the following is the most likely explanation for a buildup of cholesterol molecules in the blood of an animal?

    The animal's body cells are defective in endocytosis.

    Evolved from a photoautotrophic prokaryote

    chloroplast (B)

    Site of glucose synthesis

    Chloroplast B

    Site of transport of materials into and out of the cell

    (D) cell membrane

    Which statement best describes the effect on water transport across the cell membrane if the aquaporin in the figure ceases to function?

    Water molecules will still be able to move across the cell membrane but at a slower rate.

    Which of the following statements best explains the observations represented in Figure 1 ? CELL POND IN WATER

    There was a net movement of water out of the cell suspended in the sugar solution and a net movement of water into the cell suspended in the distilled water.

    Sign up and see the remaining cards. It’s free!

    Boost your grades with unlimited access to millions of flashcards, games and more.

    Continue with Google

    Continue with Facebook

    Already have an account?

    Sets with similar terms

    Semester 1 Midterm AP Biology

    50 terms Alayssa_Camano

    Microbes Exam 1

    53 terms amandagacicia

    Practice 1st Semester Final Tst

    93 terms TheSnicklefritz

    Cell and Homeostasis Unit Exam

    30 terms haleygillilan

    Sets found in the same folder

    ap biology exam

    17 terms shaemia

    Biology Unit 1 Exam

    27 terms Hemiorange

    AP bio - Membranes

    25 terms lornastewart

    AP Bio Unit 5 FRQ's

    11 terms dradfar

    Other sets by this creator

    nursing theory

    192 terms kristina_aleksanyan

    bio progress checks

    69 terms kristina_aleksanyan

    unit 5 cross examination

    35 terms kristina_aleksanyan

    ch 6 spanish

    25 terms kristina_aleksanyan

    Verified questions

    BIOLOGY

    (a) Use capital letters to write a three-letter wore that appears exactly the same when viewed in a plane mirror. (b) Use capital letters to write a three-letter wore that appears as a different word when viewer in a plane mirror

    Verified answer BIOLOGY

    The semicircular canals and the two tiny sacs located behind them help maintain a. night vision. b. equilibrium. c. respiratory rate. d. temperature.

    Verified answer BIOLOGY

    The camel family originated in North America. Explain why there are no camels in North America now:

    Verified answer BIOLOGY

    Write a short answer to each of these questions. (a) Neptune's average distance from the Sun is 4 497 000 000 km. What is Neptunes average distance from the Sun in astronomical units (AU)?

    Verified answer

    Other Quizlet sets

    Overview of the Reproductive system FKN

    18 terms fntumy

    Quiz 7

    32 terms Paleo2613

    Bones of the face, A&P Practice Test Cha…

    103 terms Brent_BaldwinPLUS

    Energy Test Review Quizlet Chem

    20 terms TofN

    Related questions

    QUESTION

    What are the alveoli covered in and why?

    7 answers QUESTION

    What does a cis-isomer look like?

    15 answers QUESTION

    why is the metastatic process so inefficient?

    7 answers QUESTION

    what are the critically important functions of calcium?

    7 answers 1/6

    Source : quizlet.com

    Response of chlorophyll a to total nitrogen and total phosphorus concentrations in lotic ecosystems: a systematic review protocol

    Eutrophication of freshwater ecosystems resulting from nitrogen and phosphorus pollution is a major stressor across the globe. Despite recognition by scientists and stakeholders of the problems of nutrient pollution, rigorous synthesis of scientific evidence is still needed to inform nutrient-related management decisions, especially in streams and rivers. Nutrient stressor-response relationships are complicated by multiple interacting environmental factors, complex and indirect causal pathways involving diverse biotic assemblages and food web compartments, legacy (historic) nutrient sources such as agricultural sediments, and the naturally high spatiotemporal variability of lotic ecosystems. Determining nutrient levels at which ecosystems are affected is a critical first step for identifying, managing, and restoring aquatic resources impaired by eutrophication and maintaining currently unimpaired resources. The systematic review outlined in this protocol will compile and synthesize literature on the response of chlorophyll a to nutrients in streams, providing a state-of-the-science body of evidence to assess nutrient impacts to one of the most widely-used measures of eutrophication. This review will address two questions: “What is the response of chlorophyll a to total nitrogen and total phosphorus concentrations in lotic ecosystems?” and “How are these relationships affected by other factors?” Searches for published and unpublished articles (peer-reviewed and non-peer-reviewed) will be conducted using bibliographic databases and search engines. Searches will be supplemented with bibliography searches and requests for material from the scientific and management community. Articles will be screened for relevance at the title/abstract and full text levels using pre-determined inclusion criteria; 10% (minimum 50, maximum 200) of screened papers will be examined by multiple reviewers to ensure consistent application of criteria. Study risk of bias will be evaluated using a questionnaire developed from existing frameworks and tailored to the specific study types this review will encounter. Results will be synthesized using meta-analysis of correlation coefficients, as well as narrative and tabular summaries, and will focus on the shape, direction, strength, and variability of available nutrient-chlorophyll relationships. Sensitivity analysis and meta-regression will be used to evaluate potential effects of study quality and modifying factors on nutrient-chlorophyll relationships.

    Systematic Review Protocol

    Open Access

    Published: 25 July 2017

    Response of chlorophyll to total nitrogen and total phosphorus concentrations in lotic ecosystems: a systematic review protocol

    Micah G. Bennett, Kate A. Schofield, Sylvia S. Lee & Susan B. Norton

    volume

    6, Article number: 18 (2017) Cite this article

    5316 Accesses 19 Citations 8 Altmetric Metrics details

    Abstract

    Background

    Eutrophication of freshwater ecosystems resulting from nitrogen and phosphorus pollution is a major stressor across the globe. Despite recognition by scientists and stakeholders of the problems of nutrient pollution, rigorous synthesis of scientific evidence is still needed to inform nutrient-related management decisions, especially in streams and rivers. Nutrient stressor-response relationships are complicated by multiple interacting environmental factors, complex and indirect causal pathways involving diverse biotic assemblages and food web compartments, legacy (historic) nutrient sources such as agricultural sediments, and the naturally high spatiotemporal variability of lotic ecosystems. Determining nutrient levels at which ecosystems are affected is a critical first step for identifying, managing, and restoring aquatic resources impaired by eutrophication and maintaining currently unimpaired resources. The systematic review outlined in this protocol will compile and synthesize literature on the response of chlorophyll to nutrients in streams, providing a state-of-the-science body of evidence to assess nutrient impacts to one of the most widely-used measures of eutrophication. This review will address two questions: “ a to and

    Methods

    Searches for published and unpublished articles (peer-reviewed and non-peer-reviewed) will be conducted using bibliographic databases and search engines. Searches will be supplemented with bibliography searches and requests for material from the scientific and management community. Articles will be screened for relevance at the title/abstract and full text levels using pre-determined inclusion criteria; 10% (minimum 50, maximum 200) of screened papers will be examined by multiple reviewers to ensure consistent application of criteria. Study risk of bias will be evaluated using a questionnaire developed from existing frameworks and tailored to the specific study types this review will encounter. Results will be synthesized using meta-analysis of correlation coefficients, as well as narrative and tabular summaries, and will focus on the shape, direction, strength, and variability of available nutrient-chlorophyll relationships. Sensitivity analysis and meta-regression will be used to evaluate potential effects of study quality and modifying factors on nutrient-chlorophyll relationships.

    Background

    Nutrient pollution by nitrogen (N) and phosphorus (P)—defined here as nutrient concentrations higher than background or natural levels—is a major stressor of freshwater ecosystems, both across the United States and globally [1,2,3,4,5,6]. Nutrients and resulting stressors (e.g. oxygen depletion) degrade ecosystem services worth more than $2.2 billion annually in the United States alone [7]. Despite recognition by scientists and stakeholders that nutrient pollution and resulting eutrophication (increased ecosystem metabolism) are problems in fresh waters [1, 4, 5, 8, 9], rigorous synthesis of scientific evidence is still needed to inform nutrient-related management decisions and policies, particularly in streams and rivers [10]. There are several factors that complicate nutrient stressor-response relationships in lotic systems. Several potential nutrient constituents (e.g. nitrate, ammonia) can act as stressors. Causal pathways between nutrients stressors and biological effects are complex and include many indirect effects. These pathways also involve diverse assemblages (e.g. algae, macroinvertebrates, fishes) and food web compartments (e.g. “green” pathways involving primary producers, “brown” pathways involving heterotrophic bacteria and fungi [11, 12]); and many interacting environmental factors are also involved, such as land use, flooding, and stream size, affect stressor-response relationships [13,14,15]. Temporal factors also complicate relationships, with legacy (historic) nutrient sources contributing to stressors [3, 16, 17]. Finally, high spatiotemporal variability of both nutrient concentrations [18] and lotic systems more generally [19] can complicate evaluation of stressor-response relationships in these systems. The effects of nutrient increases on biota have been documented in streams and rivers with a variety of biological, chemical, and physical conditions; however, to our knowledge, a synthesis of links between nutrient increases and impacts on stream biota that also addresses the influence of differing conditions across a breadth of lotic systems is lacking [20].

    Biota integrate impacts over time and so can better represent ecological condition compared to snapshot water quality measurements [21,22,23,24]. Environmental managers often use this biological information to evaluate impacts of chronic pollution (e.g. [25]). However, high spatiotemporal variability and other factors (e.g. those mentioned above) can mask links between nutrients and biota [26]. A synthesis of nutrient stressor-response relationships and how these relationships are modified by other factors could aid the setting of regulatory limits and identification impacted systems based on biota (e.g. [27]).

    Source : environmentalevidencejournal.biomedcentral.com

    Do you want to see answer or more ?
    James 9 month ago
    4

    Guys, does anyone know the answer?

    Click For Answer