A Comparison of Methods for Assessment of Nutrient Deficiency of Phytoplankton in a Large Oligotrophic Lake

1990 ◽  
Vol 47 (12) ◽  
pp. 2328-2338 ◽  
Author(s):  
Walter K. Dodds ◽  
John C. Priscu
Keyword(s):  
Thermal Stratification ◽  
Carbon Fixation ◽  
Algal Growth ◽  
Nutrient Deficiency ◽  
Short Term ◽  
P Deficiency ◽  
Flathead Lake ◽  
Dark Carbon Fixation ◽  
Nutrient Amendments

Short-term (h) and Song-term (d) changes in phytoplankton community physiology and bsomass in response to nutrient enrichment were used concomitantly as bioassays of phytoplankton nutrient deficiency in oligotrophic Flathead Lake, Montana, six times over the course of a year. Long-term bioassays consisted of nutrient amendments to epilimnetic water in 20 L containers which were subsequently monitored for algal growth. Short-term bioassays included measurement of NH4+ stimulation of dark carbon fixation, measurement of PO43− and NH4+ uptake over time to assess depletion of internal pools and stimulation effects of PO43− on NH4+ uptake and NH4+ on PO43− uptake. During thermal stratification, simultaneous additions of NH4+ and PO43− in long-term bioassays caused significant increases in chlorophyll a concentration, photosynthetic 14CO2 uptake, and particulate N concentration within 4.5 d; single additions of NH4+ or PO43− had little or no effect. During winter mixing there was little evidence for N or P deficiency in either short- or long-term bioassays. In general, short-term bioassays did not consistently agree with each other or with long-term bioassays. Our results suggest that it may be necessary to elicit growth of phytoplankton with nutrient addition to make definitive statements regarding nutrient deficiency.

Extraction of Algal ATP and Interpretation of Measurements

1984 ◽  
Vol 41 (11) ◽  
pp. 1601-1608 ◽  
Author(s):  
L. L. Hendzel ◽  
F. P. Healey
Keyword(s):  
Phosphorus Deficiency ◽  
Direct Injection ◽  
Nutrient Deficiency ◽  
Long Term Effects ◽  
Short Term ◽  
P Deficiency ◽  
Short And Long Term ◽  
N Deficiency ◽  
Algal Cultures

We compared ATP samples collected by direct injection with those collected by filtration from exponential and P-limited algal cultures, and from summer populations of several lakes. The direct injection method yielded higher amounts of measurable ATP than did filtration on 2.5- and 4.5-cm diameter membrane filters. ATP lost to the filtrate was negligible. Variation in ATP content with increasing nutrient deficiency was measured on six cultures. ATP/C decreased with N deficiency and to a greater degree with P deficiency. Large changes of ATP/C usually occurred with little change in viability of the cells. Short-term (1 h) nutrient enrichments generally did not change the ATP/C ratio. Phosphorus deficiency tended to increase the chlorophyll/ATP ratio and N deficiency to decrease it. We found that the short- and long-term effects of alkaline phosphatase on ATP extracts from P-sufficient and P-deficient Scenedesmus quadricauda were negligible. There appeared to be little effect on frozen ATP samples stored up to 60 d. Any short-term effects were similarly negligible, since temperature and the addition of P did not affect the rate of ATP loss. The use of 0.33 mol H3PO4∙L−1 as an extractant proved to be completely unreliable.

SECULAR VARIATIONS IN THE 14C CONCENTRATION OF DOUGLAS FIR TREE RINGS

1966 ◽  
Vol 3 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Willy Dyck
Keyword(s):  
Large Scale ◽  
Carbon Fixation ◽  
Douglas Fir ◽  
Sunspot Activity ◽  
Short Term ◽  
Fixation Rate ◽  
Pumping Rate ◽  
Counting Error ◽  
Annual Growth Rings

Measurements of the 14C concentration in a Douglas fir from Vancouver Island indicate a maximum variation of 44‰, during the past 1 100 years. The magnitude and trend of these variations are similar to those observed by de Vries (1958) in oak from Germany and by Willis et al. (1960) in sequoias from California, confirming earlier observations that atmospheric mixing of CO2 takes place rapidly on a large scale.14C measurements of successive annual growth rings from the piths of two firs (346 years and 1 142 years old) show no variations beyond those attributable to the statistical counting error of ± 6‰. Thus, cyclic variations in sunspot activity and (or) climate, if present during these intervals, did not affect the 14C concentration in the biosphere appreciably.A mechanism, based on a climate-sensitive carbon pumping rate of the biosphere coupled with the temperature-dependent oceanic CO2 content is postulated to explain, qualitatively, the observed short-term (150 years or less) and long-term (1 000 years or more) 14C variations in the land biosphere. Short-term fluctuations are directly proportional to temperature because variations in the carbon fixation rate lead to a pulsating CO2 content of the atmosphere. Long-term changes are inversely proportional to temperature because large quantities of carbon, normally stored in deeper regions of the ocean, are exchanged between biosphere and hydrosphere.

scholarly journals A 40-million-year history of atmospheric CO 2

2013 ◽  
Vol 371 (2001) ◽  
pp. 20130096 ◽  
Author(s):  
Yi Ge Zhang ◽  
Mark Pagani ◽  
Zhonghui Liu ◽  
Steven M. Bohaty ◽  
Robert DeConto
Keyword(s):  
Middle Miocene ◽  
Carbon Fixation ◽  
Middle Eocene ◽  
Ice Sheet ◽  
Algal Growth ◽  
Equatorial Atlantic ◽  
Antarctic Ice Sheet ◽  
The Past ◽  
Wide Range

The alkenone– p CO 2 methodology has been used to reconstruct the partial pressure of ancient atmospheric carbon dioxide ( p CO 2 ) for the past 45 million years of Earth's history (Middle Eocene to Pleistocene epochs). The present long-term CO 2 record is a composite of data from multiple ocean localities that express a wide range of oceanographic and algal growth conditions that potentially bias CO 2 results. In this study, we present a p CO 2 record spanning the past 40 million years from a single marine locality, Ocean Drilling Program Site 925 located in the western equatorial Atlantic Ocean. The trends and absolute values of our new CO 2 record site are broadly consistent with previously published multi-site alkenone–CO 2 results. However, new p CO 2 estimates for the Middle Miocene are notably higher than published records, with average p CO 2 concentrations in the range of 400–500 ppm. Our results are generally consistent with recent p CO 2 estimates based on boron isotope-pH data and stomatal index records, and suggest that CO 2 levels were highest during a period of global warmth associated with the Middle Miocene Climatic Optimum (17–14 million years ago, Ma), followed by a decline in CO 2 during the Middle Miocene Climate Transition (approx. 14 Ma). Several relationships remain contrary to expectations. For example, benthic foraminiferal δ 18 O records suggest a period of deglaciation and/or high-latitude warming during the latest Oligocene (27–23 Ma) that, based on our results, occurred concurrently with a long-term decrease in CO 2 levels. Additionally, a large positive δ 18 O excursion near the Oligocene–Miocene boundary (the Mi-1 event, approx. 23 Ma), assumed to represent a period of glacial advance and retreat on Antarctica, is difficult to explain by our CO 2 record alone given what is known of Antarctic ice sheet history and the strong hysteresis of the East Antarctic Ice Sheet once it has grown to continental dimensions. We also demonstrate that in the Neogene with low CO 2 levels, algal carbon concentrating mechanisms and spontaneous biocarbonate–CO 2 conversions are likely to play a more important role in algal carbon fixation, which provides a potential bias to the alkenone– p CO 2 method.

scholarly journals Abiotic and biotic processes that drive carboxylation and decarboxylation reactions

2020 ◽  
Vol 105 (5) ◽  
pp. 609-615
Author(s):  
Cody S. Sheik ◽  
H. James Cleaves ◽  
Kristin Johnson-Finn ◽  
Donato Giovannelli ◽  
Thomas L. Kieft ◽  
...  
Keyword(s):  
Metabolic Pathways ◽  
Subduction Zones ◽  
Carbon Fixation ◽  
Prebiotic Chemistry ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Short Term ◽  
Planetary Evolution ◽  
Broad Overview

Abstract Carboxylation and decarboxylation are two fundamental classes of reactions that impact the cycling of carbon in and on Earth’s crust. These reactions play important roles in both long-term (primarily abiotic) and short-term (primarily biotic) carbon cycling. Long-term cycling is important in the subsurface and at subduction zones where organic carbon is decomposed and outgassed or recycled back to the mantle. Short-term reactions are driven by biology and have the ability to rapidly convert CO2 to biomass and vice versa. For instance, carboxylation is a critical reaction in primary production and metabolic pathways like photosynthesis in which sunlight provides energy to drive carbon fixation, whereas decarboxylation is a critical reaction in metabolic pathways like respiration and the tricarboxylic acid cycle. Early life and prebiotic chemistry on Earth likely relied heavily upon the abiotic synthesis of carboxylic acids. Over time, life has diversified (de)carboxylation reactions and incorporated them into many facets of cellular metabolism. Here we present a broad overview of the importance of carboxylation and decarboxylation reactions from both abiotic and biotic perspectives to highlight the importance of these reactions and compounds to planetary evolution.

scholarly journals Hyper-Nutrient Enrichment Status in the Sabalan Lake, Iran

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2874
Author(s):  
Roohollah Noori ◽  
Elmira Ansari ◽  
Yong-Wook Jeong ◽  
Saber Aradpour ◽  
Mohsen Maghrebi ◽  
...  
Keyword(s):  
Nutrient Enrichment ◽  
Management Practices ◽  
Storage Capacity ◽  
Limiting Factors ◽  
Molar Ratio ◽  
Anthropogenic Factors ◽  
Short Term ◽  
Reservoir Water ◽  
P Deficiency

Lakes/reservoirs are rapidly deteriorating from cultural eutrophication due to anthropogenic factors. In this study, we aimed to (1) explore nutrient levels in the Sabalan dam reservoir (SDR) of northwest Iran, (2) determine the reservoir water fertility using the total phosphorus (TP)based and total nitrogen (TN)based Carlson trophic state indices, and (3) specify primary limiting factors for the reservoir eutrophication. Our field observations showed a state of hyper-nutrient enrichment in the SDR. The highest variation of TN in the reservoir water column happened when the reservoir was severely stratified (in August) while the highest variation of TP took place when the thermocline was attenuated with the deepening of the epilimnion (in October). Both TP and TN based trophic indicators classified the SDR as a hypereutrophic lake. TN:TP molar ratio averaged at the epilimnion indicated a P–deficiency in the reservoir during warm months whilst it suggested a co–deficiency of P and N in cold months. Given the hyper-nutrient enrichment state in the reservoir, other drivers such as water residence time (WRT) can also act as the main contributor of eutrophication in the SDR. We found that WRT in the SDR varied from hundreds to thousands of days, which was much longer than that of other reservoirs/lakes with the same and even much greater storage capacity. Therefore, both hyper-nutrient enrichment and WRT mainly controlled eutrophication in the reservoir. Given time consuming and expensive management practices for reducing nutrients in the watershed, changes in the SDR operation are suggested to somewhat recover its hypereutrophic state in the short-term. However, strategic long-term recovery plans are required to reduce the transition of nutrients from the watershed to the SDR.

scholarly journals Use of Alternative Containers for Long- and Short-term Greenhouse Crop Production

2015 ◽  
Vol 25 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Renee Conneway ◽  
Sven Verlinden ◽  
Andrew K. Koeser ◽  
Michael Evans ◽  
Rebecca Schnelle ◽  
...  
Keyword(s):  
Crop Production ◽  
Algal Growth ◽  
Consumer Preference ◽  
Dry Weight ◽  
Short Term ◽  
Greenhouse Production ◽  
Greenhouse Crops ◽  
Shoot Dry Weight ◽  
Puncture Strength

While research on the use of alternative containers for greenhouse production is growing, most studies have focused on a limited number of types of alternative containers and primarily on short-term greenhouse crops. With the recent release of several new bioplastic alternatives, comparisons to established alternative containers and production of longer rotation ornamental crops should be investigated. Our work, therefore, investigates the performance of ten commercially available alternative containers and their effects on both a short-term ‘Sunpatiens Compacta’ impatiens (Impatiens ×hybrida) and a long-term greenhouse crop ‘Elegans Ice’ lavender (Lavendula angustifolia) at four different locations. Results indicated that plant growth in terms of dry weight differed by container at most locations. Combined analysis of all locations showed that only straw and a bioplastic sleeve outperformed plastic pots in terms of shoot dry weight and then only after 12 weeks of production. Leachate pH, but not electrical conductivity (EC), varied by container in both the short- and long-term crop with alternative containers made from composted cow manure and peat showing consistently higher and lower pH readings, respectively. Postharvest container strength varied significantly by container, with the plastic control maintaining the highest puncture resistance after both 6 and 12 weeks, in some instances matched by the puncture strength of coconut fiber pots. Some alternative containers, in particular, wood, manure, and peat showed algal growth after 6 and 12 weeks of greenhouse production. We conclude that while some alternative containers were linked to increased growth, most showed growth equal to the plastic control, and could therefore make appropriate alternatives to plastic pots. However, changes in pH, low puncture strengths after production, higher denesting times, and algal growth on manure, wood, and peat may make these pots less desirable alternatives than other pots under investigation. However, other factors not studied here, such as compostability, biodegradability in the landscape, water use, consumer preference, aesthetics, compatibility with mechanized operations, and cost may also need to be taken into account when deciding on an appropriate container for greenhouse production.

scholarly journals Nutrition-mediated cell and tissue-level anatomy triggers the covariation of leaf photosynthesis and leaf mass per area

2020 ◽  
Vol 71 (20) ◽  
pp. 6524-6537 ◽  
Author(s):  
Zhifeng Lu ◽  
Tao Ren ◽  
Jing Li ◽  
Wenshi Hu ◽  
Jianglin Zhang ◽  
...  
Keyword(s):  
Carbon Fixation ◽  
Mass Density ◽  
Nutrient Deficiency ◽  
Carbon Assimilation ◽  
Tissue Level ◽  
Leaf Mass Per Area ◽  
Mesophyll Cells ◽  
P Deficiency ◽  
Leaf Mass ◽  
K Deficiency

Abstract Plants in nutrient-poor habitats converge towards lower rates of leaf net CO2 assimilation (Aarea); however, they display variability in leaf mass investment per area (LMA). How a plant optimizes its leaf internal carbon investment may have knock-on effects on structural traits and, in turn, affect leaf carbon fixation. Quantitative models were applied to evaluate the structural causes of variations in LMA and their relevance to Aarea in rapeseed (Brassica napus) based on their responses to nitrogen (N), phosphorus (P), potassium (K), and boron (B) deficiencies. Leaf carbon fixation decreased in response to nutrient deficiency, but the photosynthetic limitations varied greatly depending on the deficient nutrient. In comparison with Aarea, the LMA exhibited diverse responses, being increased under P or B deficiency, decreased under K deficiency, and unaffected under N deficiency. These variations were due to changes in cell- and tissue-level carbon investments between cell dry mass density (N or K deficiency) and cellular anatomy, including cell dimension and number (P deficiency), or both (B deficiency). However, there was a conserved pattern independent of nutrient-specific limitations—low nutrient availability reduced leaf carbon fixation but increased carbon investment in non-photosynthetic structures, resulting in larger but fewer mesophyll cells with a thicker cell wall but a lower chloroplast surface area appressed to the intercellular airspace, which reduced the mesophyll conductance and feedback-limited Aarea. Our results provide insight into the importance of mineral nutrients in balancing the leaf carbon economy by coordinating leaf carbon assimilation and internal distribution.

Community composition and functional genes as well as ecological role of bacteria attached to different bloom-forming cyanobacteria

2020 ◽  
Author(s):  
Chunlei Song ◽  
Liu Yang ◽  
Xiuyun Cao ◽  
Xiaoyan Chen ◽  
Qinghui Deng ◽  
...  
Keyword(s):  
Organic Phosphorus ◽  
Algal Growth ◽  
Nutrient Deficiency ◽  
Functional Differentiation ◽  
Cyanobacterial Blooms ◽  
Functional Genes ◽  
Fish Ponds ◽  
P Deficiency ◽  
N Limitation ◽  
Attached Bacteria

Abstract Background Eutrophication leads to frequent outbreaks of cyanobacterial blooms, especially those of the genera Dolichospermum and Microcystis. The contribution of bacteria attached to algal cells to cyanobacterial blooms is still not clear and specific. To gain a deeper understanding of functional genes and their role in bacteria attached to different bloom-forming cyanobacteria, we carried out microbial experiments associated with Dolichospermum and Microcystis in four fish ponds. Results The significantly positive relationships between Dolichospermum density and total nitrogen (TN) and between Microcystis density and particle nitrogen (PN) indicated the strong nitrogen (N) demand of these two species. The lack of functional genes mediating the nitrification process in bacteria attached to both Microcystis and Dolichospermum indicated that these two species preferred ammonium (NH 4 + -N). Dolichospermum could overcome N limitation through N 2 fixation expressed by high nitrogenase genes abundance. Compared to bacteria attached to Dolichospermum cells, bacteria attached to Microcystis cells showed a higher activity of leucine aminopeptidase (LAP) and a significantly higher abundance of functional genes (such as nrfA , nirB and aminopeptidase genes) mediating the dissimilatory nitrate reduction to ammonium (DNRA). The significantly higher abundance of functional genes (carbon degradation) and β-glucosidase (GLU) activity of bacteria attached to Microcystis than those of bacteria attached to Dolichospermum suggested the abundant organic carbon bound Microcystis cells, which was prerequisite for DNRA. Also, Microcystis had a great advantage in solving phosphorus (P) stress, including high levels of organic phosphorus hydrolysis associated with high levels of phosphatase genes of attached bacteria. The difference of functional community compositions of bacteria attached to Microcystis and Dolichospermum resulted in the functional differentiation. Conclusions Dolichospermum and Microcystis growth was susceptible to P and N (especially NH 4 + -N) limitation, respectively, the latter of which could be effectively solved by attached bacteria through DNRA and ammonification. The P acquisition disadvantage of Dolichospermum resulted in its frequent replacement by Microcystis , especially in conditions of P deficiency. Hence, the evaluation of nutrient limitation (N or P) type of algal growth should combine the nutrient concentration and ratio as well as the ability to solve nutrient deficiency.

Short- and long-term effects of irradiance and CO2 availability on carbon fixation by two marine diatoms

2003 ◽  
Vol 81 (3) ◽  
pp. 191-200 ◽  
Author(s):  
Ana Bartual ◽  
J Angel Gálvez
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Carbon Fixation ◽  
Skeletonema Costatum ◽  
Light Limitation ◽  
Long Term Effects ◽  
Short Term ◽  
Batch Cultures ◽  
Photosynthetic Rates ◽  
Long Term Trends

Unbuffered and nutrient-replete dilute batch cultures of Skeletonema costatum Cleve and Phaeodactylum tricornutum Bohlin were grown at high and low CO2 availability conditions and two incident irradiances, 150 and 30 µmol photons·m–2·s–1. Long-term combined effects of such light and CO2 availability conditions on carbon fixation rates of both diatoms were compared. At saturating light, P. tricornutum showed higher photosynthetic rates than S. costatum at both CO2 conditions. However, under subsaturating light, carbon fixation rates of P. tricornutum were higher than observed for S. costatum only at low CO2. Skeletonema costatum showed a strong reduction in photosynthetic rates only when both resources, irradiance and CO2, were low. Short-term alterations of light and CO2 availability on carbon fixation showed that the response of S. costatum differed considerably from long-term trends: the short-term reduction in CO2 availability at both light levels resulted in a considerable decrease in the maximum photosynthetic rates. This effect was much less noticeable in P. tricornutum. The results show that, at saturating light, both diatoms maintain maximum photosynthetic rates under low CO2 levels, but only P. tricornutum is well adapted to rapid changes in this resource. This capacity of adaptation seems to be light dependent, since light limitation altered the responses of both diatoms to low CO2 availability conditions.Key words: CO2, 14C fixation, irradiance, Phaeodactylum tricornutum, Skeletonema costatum.

scholarly journals Changes in photosynthetic carbon metabolism in senescent leaves of chickpea, Cicer arietinum L.

2014 ◽  
Vol 57 (1) ◽  
pp. 127-135
Author(s):  
Chandrashekhar V. Murumkar ◽  
Prakash D. Chavan
Keyword(s):  
Cicer Arietinum ◽  
Carbon Fixation ◽  
Major Change ◽  
Short Term ◽  
Cicer Arietinum L ◽  
Photosynthetic Carbon Fixation ◽  
Photosynthetic Carbon ◽  
Photosynthetic Carbon Metabolism ◽  
C Assimilation

Photosynthetic processes in mature and senescent leaves of chickpea (<em>Cicer arietinum</em> L.) have been compared. With age, leaf photosynthetic pigments viz. chlorophyll a, chlorophyll b and carotenoids, and rate of 14°C fixation were considerably affected. Analysis of δ<sup>13</sup>C, and short term photosynthetic products showed no major change in the path of photosynthetic carbon fixation. Study of long term photosynthetic <sup>14</sup>C assimilation revealed that in old senescent leaves, <sup>14</sup>C incorporation into organic acid and sugar fractions was enhanced.

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