1. 1. Longitudinal Patterns in ecological organization of Rivers Patterns in species richness Patterns in species composition Patterns in functional organization Patterns in habitats and environmental template 2. Processes and Mechanisms…

3. (Sepkowski and Rex 1974) Bivalve [Unionidae] spp in Atlantic coastal rivers

7. Longitudinal Zonation in species composition Observations Carpenter (1928) Huet (1949-1962) Illies et al. (1955,1963) Statzner (1986) Theories

8. Huet’s fish-zones of Western Europe (1949-1962)

9. Huet’s “slope rule” for western European streams

10. Source areas: glacial meltwaters, springs, wetlands, lakes. small very cold, low to moderate slopes, fauna variable Mean monthly temp rises to 20 C; high oxygen concentrations flow is turbulent; erosional, gravel-cobble substrate predominate Fauna is cold stenothermal. No true plankton. Mean monthly temp above 20 C; oxygen deficits may occur. Flow is slower, tends towards laminar. Sand and finer substrates are dominant. Fauna is eurythermal and most species well-adapted to lentic settings. Plankton develops. Crenon Rhithron Potamon Illies (1955) Major River Zones

11. Latitude: high middle low Illies and Botosaneanu (1963) Illies (1955)

12. Variables associated with longitudinal patterning changes in biological community temperature substrate hydraulics (slopes, velocities, power dissipation) Processes associated with longitudinal structure changing landscape controls on carbon production [light, nutrs, alloch source] demographic equilibria changing temperatures patterns in hydraulic stress and disturbance increasing habitat diversity with hydrologic scale population interactions (predation, competition, and disease) {changes in water quality} What causes Longitudinal variation in biological communities?

13. The River Continuum Concept [RCC] Vanote et al 1980

14. Key ideas in the RCC Hydraulic gradients organize carbon sources for the food web Hydraluic gradients organize temperature variability Community composition equilibrates to carbon sources Species diversity reflects temperature variability emphasis on continua [gradients] rather than zones

15. Sources and fate of organic carbon two general categories for sources allochthonous  from “outside” soil water, leaves, woody debris, blown in insects,etc. autochthonous  from “self” aquatic primary producers:vascular plants, algae, autotrophic bacteria terrestrial versus aquatic origin here versus there background concepts

16.      decomposers     allocthonous autochthonous DETRITAL POOL [algae+ macrophytes] invertivorous fish /birds grazers shredders collector-gathers filter-feeders invert predators [terrestrial leaves, wood, DOC ]     piscivorous fish piscivorous birds /mammals Bacteria & fungi Veloc Light Nutrients Veg Edge/area RCC background concepts

18. Relative importance of autochthonous and allochthonous inputs often a matter of physical opportunity e.g. lakes versus small woodland stream allo>auto CPOM auto>allo allo?auto DOC sometimes a matter of human intervention-e.g.: organic pollution

19. Death, Detritus and Decomposition allochthonous inputs are already usually dead or soon dead -> detrital carbon autochthonous carbon eventually dies -> detrital carbon because HOH is a solvent, the chemical nature of detritus rapidly diverges from that of living carbon role of the biota bacteria & fungi colonize detrital surface and enzymatically extract labile compounds larger macro-invertebrate shredders (caddisflies, craneflies, some stoneflies, amphipods etc.) mechanically breakup larger pieces (CPOM) while feeding on attached decomposers and in some cases on the CPOM itself… really feeding on the microbial community on the CPOM; like peanut butter on a cracker

20. Decomposition in an aquatic environment Decomposition Autolysis + leaching + mechanical breakdown + biochemical mineralization by respiration generally involves a serial reduction in both size and quality CPOM->FPOM->VFPOM DOM -> INORG C mediated by biology bacteria,fungi,shredders, fp detritivore

21. mass t = mass init * e -Kt Decomposition rates time % remaining differential decomposition rates Allochthonous: willow>alder>dogwood>maple>aspen>oak>pine&spruce Autochthonous: algae> submersed aquatic macrophytes> emergent/terrestrial macrophytes life cycle timing of shredders often cued to cued to leaf fall in temperate NA

22. 2 sources: allochthonous and authochthonous 2 pathways: detrital and herbivorous      decomposers     allocthonous autochthonous DETRITAL POOL [algae+ macrophytes] invertivorous fish /birds grazers shredders collector-gathers filter-feeders invert predators [terrestrial leaves, wood, DOC ]     piscivorous fish piscivorous birds /mammals Bacteria & fungi P/R = Ecosystem Photosynthesis /Respiration P/R ~ autoch /(autoch + alloch) P/R ~ total carbon produced/ total carbon respired

23. Photosynthesis Respiration Org Carbon Photosynthesis Respiration Org Carbon P/R>1 P/R<1 Allocthonous inputs Respiration Org Carbon P/R<1 Photosynthesis autotrophic heterotrophic Heterotrophic (dystrophic) Advective transport “downstream”

24. The River Continuum Concept [RCC] Vanote et al 1980 Caveats…

28. Species- Area Relationships Darlington 1952 Preston 1962 MacArthur and Wilson 1967 Number of individuals Number of taxa Observed: log-normal distribution Log S =.263 J/m + 3.17 S …# of spp J …# of individuals in sample m …# of individuals in rarest spp if randomly dispersed J~ area sampled S = c AREA Z Z = theoretical =.26 insular fauna=.23-.35 non-insular =.12-20 Sample size

29. Immigration rate Number of species Extirpation rate Immigration rate Number of species Extirpation rate smaller larger MacArthur and Wilson’s Equilibrium Theory [Island Biogeography 1967] harsher milder

30. Immigration rate Number of species Extirpation rate Immigration rate Number of species Extirpation rate upstream Downstream-larger upstream species pool Demographic equilibrium applied to river networks Harsher-less storage Milder-more storage- Dowbstream equilib. Upstream equilib.

31. Temperature its’ effect on biology is profound

32. Zonation and temperature

35. Some thermal changes are more important than other

36. SHORTWAVE RAD. LONGWAVE RAD. CONDUCTION CONVECTION EVAPORATION BLACKBODY Ground water ADVECTION Tributaries ADVECTION

37. d heat/dt =  Radiation (short-wave) f(SA,sunlight) Radiation (long-wave) f(SA,air temp) Back Radiation f(SA, water temp) Convection f(SA,temp diff,wind) Conduction f(Perim,soil temp) Evaporation f(SA,humidity,wind) Advection f(source temps) Heat Balance Equation: Water temp = heat units/volume * 1/specific heat Proximate mechanism:heat Budget

38. d heat = Radiation (short-wave) f(SA,sunlight) Radiation (long-wave) f(SA,air temp) Back Radiation f(SA, water temp) Convection f(SA,air-water temp diff, wind) Conduction f(Perim,soil-water temp diff) Evaporation f(SA,water temp, humidity,wind) Advection f( confluing source temps) when d heat = 0, temperature  equilibrium (constant) Temp equil = T 0 e -kt Proximate mechanism:heat Budget

39. Longitudinal effects: TeTe Velocity? Volume (Q) ? Proximate mechanism:heat Budget Runoff routing GW routing

40. Ultimate mechanism:landscape d heat/dt =  Radiation (short-wave) f(SA,sunlight) Radiation (long-wave) f(SA,air temp,riparian structure) Back Radiation f(SA, water temp) Convection f(SA,air-water temp diff, wind) Conduction f(Perim,soil-water temp diff) Evaporation f(SA, temp, humidity diff,wind) Advection f( confluing source temps &vol) Stratification effects f(lentic volume,SA,strat) riparian shade,climate water temperature channel shape,climate wind, riparian conditions hydro-geology,landuse lakes,wetlands,reservoirs Key modifying factors heat content proportional to volume heat flux proportional to surface area

41. July mean C o Watershed Area km 2

42. Diel effects: T e _day T e _night Velocity? Volume (Q) ? Proximate mechanism:heat Budget

43. Upper Cedar April, 2003 Lower Cedar April, 2003

44. Daily flux C o July mean C o Watershed Area km 2

45. Daily flux C o

47. Longitudinal Gradients in depth, velocity, substrate, shear stress,

48. Velocity Diffusion, Reaeration & metabolism Position and movement shear substrate Habitat utilization Catastrophic disturbance

49. xr.01 yr.007 zr.05 A Lotka-Volterra 3 species simulation kx600 ky1000 kz500 dx/dt = rX - (k x X -  yx Y -  zx Z) 1/k x dy/dt = rY - (k y Y -  xy X -  zy Z) 1/k y dz/dt = rZ - (k z Z -  yz Y -  xz X) 1/k z red blue green

50. Disturbance frequency = 0 Disturbance frequency = 2 Disturbance frequency = 4

51. Disturbance frequency = 0 Disturbance frequency = 7 Disturbance frequency = 13

52. Disturbance frequency = 0 Disturbance frequency = 20 Disturbance frequency = 100

53. Log Frequency of Disturbance Number of species Total population size Intermediate Disturbance Hypothesis

54. Nutrient gradients and the regional structure of stream communities C.H.Riseng, M.J Wiley and R.J. Stevenson 2 Geomorphic effects on Biology

55. What kinds of Disturbances might potentially shape stream insect communities? High Flow events (Floods) Low flow events (Droughts) Pathogen outbreaks (Disease)

56. Velocity Diffusion, Reaeration & metabolism Position and movement shear substrate Habitat utilization Catastrophic disturbance

57. Fick’s Law again provides a basic description of this diffusive process diff rate = K (saturation - concentration) diff rate = kA/L (pO 2 inside - pO 2 outside) k=rate constant characteristic of the type of tissue oxygen must diffuse across (gill, cell wall. etc.) A= exchange surface area where diffusion can occur L= diffusion distance (how far molecules must travel) (pO 2 inside - pO 2 outside)= gradient in partial pressure of oxygen Because the rate of molecular diffusion is faster in air than in water all organisms that take dissolved oxygen from the water to support their metabolism face a fundamental physical constraint related to diffusion rate:

58. (pO2 inside - pO2 outside)  gradient in oxygen concentration effectively depends on the external oxygen concentration since internal oxygen levels almost always low for a simple imaginary organism time  resp rate

59. begins with resp rate set by kA/L and the external O 2 concentration but rate of resp decreases with time occurs because of O 2 depletion immediately around exchange surface average diffusion distance average diffusion distance average diffusion distance time 1 time 2 time 3 time  resp rate Intrinsic problem with diffusion in water due to relatively low diffusion coeff in water solution: ventilate  replace water at exchange surface

60. Stenacron As the environmental O 2 concentration declines, the concentration gradient in Fick’s eq, also declines... regulators must compensate by ventilating more rapidly in order to decrease the diffusion distance and offset the gradient decline.

61. Many aquatic animals actively ventilate exchange surfaces ventilation periodically replaces spent water  controlling deterioration of diffusion distance animals which manipulate diffusion distance or other parameters of Fick’s law are called respiratory regulators animals ventilate by different methods e.g. mayflies, fish, dragonflies

62. Not all aquatic animals invest energy and tissue in diffusion regulation organisms which let their respiration rate vary with ambient O2 levels are called respiratory [ metabolic] conformers

63. For conformers current velocity can act as a substitute for O 2 concentration in terms of regulating respiration rates. For regulators reduced velocity requires more work and therefore energy Concentration-velocity tradeoffs

64. Heterotroph oxygen requirements Even regulators have a concentration below which they can not further compensate by ventilation, below that critical concentration metabolic rate declines with declining oxygen. For regulators, this critical concentration represents a concentration threshold below which an organisms energy supply rapidly declines. When respiration rates are only sufficient meet current maintenance costs, there is no excess eenergy to invest in foraging, growth or reproduction. The concentration of oxygen which provides only this level of respiration is known as the incipient lethal level, since an organism/population (although it may live for some time) cannot achieve reproductive below this level. At some low concentration (the acute lethal level) respiration rate is so far below immediate maintenance needs that rapid death follows. } scope for activity critical concentration incipient lethal level acute lethal level maintenance rate Respiration rate Oxygen concentration ---->

65. Sublethal affects of low oxygen When [O 2 ] lies between the critical concentration and the incipient lethal level, an organisms ability to do physiological work is diminished. reduced oxygen can have important sublethal affects on feeding, growth, locomotion and even survival

67. Concentrations below 1-2 ppm are lethal to a wide array of aquatic organisms. Concentrations below 4 ppm are lethal to many, a common regulatory water quality standard. Some organisms can survive <1 ppm (are especially tolerant) and dominate low oxygen environments. Velocity - [O 2 ] tradeoffs can be important here too, especially for conformers. Lethal Limits Acute lethal levels of oxygen vary considerably between organisms Acute lethal [O 2 ] ppm 1 2 3 4 5 6 current velocity cm sec -1

68. ATMOSPHERE Henry's law for gases dissolved in water [c]=solubility * partial pressure [c]is the equilibrium saturationconc =the concentration the system reaches if left alone note it is independent of starting concentration What determines Oxygen concentrations?

69. ATMOSPHERE

71. Fick’s Law provides a basic description of the rate at which diffusive processes occur. diffusion rate = K ([Saturation] - [O 2 ] ) k = rate constant, sometimes called the diffusivity Bulk reaeration rate k = f[molecular diffusivity and eddy diffusion (turbulence)] How long does it take Oxygen to reach saturation? ATMOSPHERE

72. time  diffusion rate Saturation 0 Fick’s Law implies that Oxygen concentration approach equilibrium asymptotically When [saturation-DO] is large, rates of exchange with the atm are high When [saturation-DO] is small, rates of exchange are small The direction of oxygen exchange depends on Henry’s law if over-saturated (supersaturated) water will lose oxygen to atmosphere if under-saturated, water will gain oxygen from the atmosphere diffusion rate = K ([Saturation] - [O 2 ] )

73. Mass Input 1 Input 2 Output 1 Output 2 Boxes = mass storage arrows = rates of flux then  mass in storage per unit time =  inputs -  outputs For the example diagram above d/dt Mass= [ (Input 1 + Input 2) - (Output 1 + Output 2) ] Using a Mass Balance Approach

74. photosynthesis respiration diffusive aeration O2O2 ATM  O 2 = Photosynthesis - Respiration  diffusion d/dt O 2 = [ P - R  k([saturation]-[O 2 ]) ] Mass balance for O 2

75. Respiration due organic pollution Carbon and nitrogen (ss +diss) diffusive aeration O2O2 ATM  O 2 = Respiration  diffusion d/dt O 2 = [ R  k([saturation]-[O 2 ]) ] predicts an temporary oxygen sag downstream form sewage plant effluents Streeter-Phelps Model

76. DAY NIGHT diffusion P - R supersaturated +++++++++++++++++++++----------------------------------++ ++++++++++------------------------------------++++++++ 100% Saturation DAY NIGHT diffusion P - R supersaturated ---++++++++++++++++++-------------------------------------- +++++++++-------------------------------++++++++ 100% Saturation DAY NIGHT diffusion P - R supersaturated -+++++++++++++++++------------------------------- +++++++++++------------------------------------++++++++++ 100% Saturation When biological rates are high (e.g., nutrient- rich systems like agricultural streams) or diffusion rates are relatively slow (e.g. stagnant ponds), biological processes can swamp diffusion rates and lead to widely fluctuating diel curves The shape of this diel oxygen curve is determined by the relative magnitude of the component rates [diffusion, photosynthesis and respiration]. When diffusion rates are high due a high reaeration coefficient (k) and biological rates are relatively low, almost no diel sag is detectable-- diffusion swamps the P-R term in the mass balance. Diffusion is a constant process, but biological activity is not. Photosynthesis varies in a regular diel fashion following the availability of light. The O 2 mass balance equation can be thought of as having two distinct forms: during the day  DO=P-R± k[saturation-DO] but during the night  DO=R± k[saturation-DO] since P=0

77. Velocity Diffusion, Reaeration & metabolism Position and movement shear substrate Habitat utilization Catastrophic disturbance

78. Where Homogeneous longitudinal units [ geomorphic/ecologic] data Landscape (GIS) data Registered field data Model projections Mapping approaches to Longitudinal Structure Current examples: MRI-VSEC (IL,WI verions); TNC Macrohabitat Classifications USGS Aquatic GAP program Geomorphic Valley Segment Classifications [Hupp] Geomorphic Reach Classifications [Rosgen] Scale Valley segments Reaches Basins

79. What is Ecological Unit Mapping? Hydrologic character Biological character Chemical character Integrated Ecological Character of a River Segment “Identifying the basic [structural] units of nature” (Rowe 1991) Geomorphic character

80. Raisin River mainstem units Central role of GIS

81. Michigan Rivers Inventory VSEC units MAP 10 km 270 main river segments and 400 tributary units [mri-vsec v1.1]

82. Grazers: Animals that feed on living algae or macrophyte tissue. Some are free roaming, others are central-lace foragers making short excursions out from some central tube or burrow.Specialization by growth form common but not by plant species. Food types: algae, vascular plant tissue (rare) examples: many mayflies, many midges, many cased caddisflies, some stoneflies

83. Shredders: Animals that feed on large allochthonous organic carbon fragments (e.g.leaves) which have been colonized by bacterial and fungal communities. Some shedders have commensal gut flora to assist in the digestion of cellulose. A few have specialized enzymes to assist in the same task.. Food types: coarse particulate carbon (CPOM), and associated microflora examples: Cranefly larvae (Tipula), Giant stoneflies (Pteronarcys), many cased caddisflies, scuds

84. Filter Feeders: Animals that feed by filtering suspended Organic material from the water column. Filtering mechanisms can be anatomical [e.g. blackflies] or more elaborate constructions involving silk capture nets [e.g. some Caddisflies and midges] Food types: animal, algae, detritus examples: blackflies, net-spinning caddisflies, burrowing mayflies

85. Collector-gatherers: Omnivorous animals that feed by moving around the substrate in search of fine particulate organic matter (FPOM) which is either ingested on the spot, or retrieved and accumulated at some central tube or burrow. Often includes embedded algae and even small animals. Food types: algae, detritus examples: some mayflies, many midges and worms (tubificids), scuds

86. Predators: Animals that feed on other animals. An invertivore feeds principally on invertebrates. Food types: animal tissue examples: dragonflies, many stoneflies, water scorpions and other bugs, most smaller fishes