1 / 20

Ecosystem Processes and the River Continuum Concept

Ecosystem Processes and the River Continuum Concept . Unit 1: Module 4, Lecture 5. Objectives. Students will be able to: classify sources of organic matter. diagram the flow of instream organic matter. factors that influence the storage of organic matter in streams.

adamdaniel
Download Presentation

Ecosystem Processes and the River Continuum Concept

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ecosystem Processes and the River Continuum Concept Unit 1: Module 4, Lecture 5

  2. Objectives Students will be able to: • classify sources of organic matter. • diagram the flow of instream organic matter. • factors that influence the storage of organic matter in streams. • explain the river continuum concept • compare and contrast low order, mid-order, and high order streams.

  3. geography.uoregon.edu/ .../SCRfig2-33web.jpg General organic matter pathway

  4. www.landcare.org.nz/SHMAK/ manual/6doing.htm www.bbg.org/sci/blackrock/ veg/brfredmaple.html 140.211.62.101/streamwatch/ swm10.html Sources of organic matter • Autochthonous – instream • Allochthonous – out of stream

  5. Dissolved organic matter Soluble organic compounds that leach from leaves, roots, decaying organisms, and other sources Largest pool of organic matter in streams Particulate organic matter Coarse particulate organic matter Woody material & leaves > 1 mm Fine particulate organic matter Leaf fragments, invertebrate feces, and organic precipitates < 1 mm Types of organic matter

  6. This figure depicts the routes carbon follows as it is processed within a stream. Microbes, macro-invertebrates, fish, and other organisms all play roles in the physical and chemical processing of organic matter. Instream organic matter processing The River Continuum - www.oaa.pdx.edu/CAE/Programs/ sti/pratt/energy.html

  7. A caddisfly of the family Limnephilidae Macroinvertebrate functional roles in organic matter processing • Shredders • Dominant food • Vascular macrophyte tissue • Coarse particulate organic material (CPOM) • Wood • Feeding mechanisms • Herbivores - Chew and mine live macrophytes • Detritivores - Chew on CPOM • Representatives • Scathophagidae (dung flies) • Tipulidae (crane flies)

  8. A blackfly of the family Simulidae A caddisfly of the family Hydroptilidae Macroinvertebrate functional roles • Collectors • Dominant food • Decompose fine particulate organic matter (FPOM) • Feeding mechanisms • Filterers - Detritivores • Gatherers - Detritivores • Representatives • Filterers • Hydropsychidae • Simulidae (black flies) • Gatherers • Elmidae (riffle beetles) • Chironomini • Baetis • Ephemerella • Hexagenia

  9. A dipteran of the family Thaumaleidae Macroinvertebrate functional roles • Scrapers • Dominant food • Periphyton (attached algae) • Material associated with periphyton • Feeding mechanisms • Graze and scrape mineral and organic surfaces • Representatives • Helicopsychidae • Psephenidae (water pennies) • Thaumaleidae (solitary midges) • Glossosoma • Heptagenia

  10. A stonefly of the family Perlidae A “true bug” of the family Notonectidae Macroinvertebrate functional roles • Predators • Dominant food • Living animal tissue • Feeding mechanisms • Engulfers - Attack prey and ingest whole animals • Piercers - Pierce tissues, suck fluids • Representatives • Engulfers • Anisoptera (dragonflies) • Acroneuria • Corydalus (hellgrammites) • Piercers • Veliidae (water striders) • Corixidae (water boatmen) • Tabanidae (deerflies & horseflies)

  11. Low concentrations in winter and fall High concentrations in summer Seasonal variation in particulate organic carbon Photos by g. merrick

  12. Organic matter that enters streams may be (percent estimates are approximate and variable): Stored within the stream bank or channel (25%) Exported downstream (50%) Metabolized and respired as carbon dioxide by organisms (25%) Photo – g. merrick Fate of organic matter

  13. Storage of organic matter • Factors that are likely to increase retention time are debris dams, beaver dams, floodplains, and geomorphological features of the stream or river that impede flow.

  14. Net primary production versus litter fall

  15. Bear Brook in New Hampshire is the site of a famous organic matter budget study (Likens, 1973). In the this small, forested headwater stream it was found that greater than 99% of the carbon input to Bear Brook came from allochthonous sources (POM slightly greater than DOM). Close to 65% of this input was exported downstream from the 1700 meter long study site. Input of DOM exceeded exports Due to leaf fall more POM was exported than entered the site Bear Brook, New Hampshire

  16. The River Continuum Concept

  17. Low order streams Shaded headwater streams Coarse particulate matter (CPOM) provides resource base for consumer community Stream order and the RCC

  18. Mid-order streams Energy inputs change as stream broadens Shading and contribution of CPOM decreases Sunlight supports significant periphyton production Upstream processing of CPOM results in input of fine particulate matter (FPOM) Stream order and the RCC

  19. Stream order and the RCC • High order streams • As streams widen even more and flows drop, macrophytes become more abundant • In the largest rivers, macrophytes are limited to the river margins because mid-channel conditions are typically too turbid • Bottom substrate becomes smaller

  20. Figure 12.1 Carbon fluxes in a stream ecosystem

More Related