Call us toll-free

Quick academic help

Don't let the stress of school get you down! Have your essay written by a professional writer before the deadline arrives.

Calculate the price

Pages:

275 Words

$19,50

and their effect on photosynthesis of aquatic plant communities.

In phytoplankton communities, a high diversity of photosynthetic pigments is associated with elevated light capture and biomass , , , . In contrast to terrestrial vascular plants, phytoplankton and macroalgae can contain a variety of photosynthetic pigments, resulting in a diverse array of colour variations within the photosynthetic thalli of rhodophyta, chlorophyta and phaeophyta. Thus, algal species may show large differences in their resource-use abilities which reflect the physiological traits underpinning any diversity–productivity relationship in assemblages. Further, within macroalgal assemblages, where light delivery to the lower portions of the canopy and sub-canopy is limited , , there are large differences in photosynthetic properties between canopy and sub-canopy species (e.g., ratio of structural to photosynthetic tissues; ) and the thallus morphology of sub-canopy species can vary considerably from size and shapes of blades, filaments, or crusts, all with unique photosynthetic traits and patterns of self-shading. Combined with high concentrations of photosynthetic pigments in shaded portions of algal thalli , sub-canopy species are often efficient light harvesters, capable of driving total assemblage NPP above that of the canopy alone , .

and photosynthesis of aquatic plant communities.

The absorption of light by autotrophic communities and fixation of carbon crucially underpins energy transfer in almost all ecosystems. Yet, despite a rich history of photosynthetic research dealing with the spectral regions of photosynthetically active radiation (PAR) used by photosynthetic organisms –, there have been few attempts to integrate measurements of spectral light attenuation and spectral light use by diverse assemblages of macroalgae. Biodiversity-ecosystem-function studies have usually found a positive relationship between plant diversity and primary productivity –, but the ecophysiological mechanisms of complementary resource use have been poorly explored . Although others have found that species identity and total biomass – are important in accounting for variation in NPP, the high diversity and turnover in macroalgal assemblages inhabiting the sub-canopy beneath larger canopy forming macroalgae suggests high niche differentiation. Pigment complementarity may, therefore, be capable of enhancing resource use efficiency within canopies, as has been demonstrated in phytoplankton assemblages , –.

Trophic state index - Wikipedia

Publications • Ocean Optics Web Book

Phototrophs underpin most ecosystem processes, but to do this they need sufficient light. This critical resource, however, is compromised along many marine shores by increased loads of sediments and nutrients from degraded inland habitats. Increased attenuation of total irradiance within coastal water columns due to turbidity is known to reduce species' depth limits and affect the taxonomic structure and architecture of algal-dominated assemblages, but virtually no attention has been paid to the potential for changes in spectral quality of light energy to impact production dynamics. Pioneering studies over 70 years ago showed how different pigmentation of red, green and brown algae affected absorption spectra, action spectra, and photosynthetic efficiency across the PAR (photosynthetically active radiation) spectrum. Little of this, however, has found its way into ecological syntheses of the impacts of optically active contaminants on coastal macroalgal communities. Here we test the ability of macroalgal assemblages composed of multiple functional groups (including representatives from the chlorophyta, rhodophyta and phaeophyta) to use the total light resource, including different light wavelengths and examine the effects of suspended sediments on the penetration and spectral quality of light in coastal waters. We show that assemblages composed of multiple functional groups are better able to use light throughout the PAR spectrum. Macroalgal assemblages with four sub-canopy species were between 50–75% more productive than assemblages with only one or two sub-canopy species. Furthermore, attenuation of the PAR spectrum showed both a loss of quanta and a shift in spectral distribution with depth across coastal waters of different clarity, with consequences to productivity dynamics of diverse layered assemblages. The processes of light complementarity may help provide a mechanistic understanding of how altered turbidity affects macroalgal assemblages in coastal waters, which are increasingly threatened by diminishing light quantity and altered spectral distributions through sedimentation and eutrophication.

Research | Yale School of Forestry & Environmental …

Ocean Optics Web Book is a collaborative web-based book on optical oceanography

Chapter 55 - Environmental Pollution Control
Order now
  • UNMATCHED QUALITY

    As soon as we have completed your work, it will be proofread and given a thorough scan for plagiarism.

  • STRICT PRIVACY

    Our clients' personal information is kept confidential, so rest assured that no one will find out about our cooperation.

  • COMPLETE ORIGINALITY

    We write everything from scratch. You'll be sure to receive a plagiarism-free paper every time you place an order.

  • ON-TIME DELIVERY

    We will complete your paper on time, giving you total peace of mind with every assignment you entrust us with.

  • FREE CORRECTIONS

    Want something changed in your paper? Request as many revisions as you want until you're completely satisfied with the outcome.

  • 24/7 SUPPORT

    We're always here to help you solve any possible issue. Feel free to give us a call or write a message in chat.

Order now
  • You submit your order instructions

  • We assign an appropriate expert

  • The expert takes care of your task

  • We send it to you upon completion

Order now
  • 37 684

    Delivered orders

  • 763

    Professional writers

  • 311

    Writers online

  • 4.8/5

    Average quality score

Order now
  • Kim

    "I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."

  • Paul

    "Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."

  • Ellen

    "Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."

  • Joyce

    "Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."

  • Albert

    "Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."

  • Mary

    "Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."

Ready to tackle your homework?

Place an order