Unit 2: Analysis of Habitats

1. Unit 2: Analysis of Habitats

2. Ecological concepts • Habitat • Environment • Population • Ecosystem • Community

3. Niche: Hutchinson’s n-dimensional hypervolume a b

4. Niche: Hutchinson’s n-dimensional hypervolume c a b

5. Niche: Hutchinson’s n-dimensional hypervolume d c a b

6. Habitat • Macrohabitat • Microhabitat • Habitat dimensions • atmosphere • lithosphere • hydrosphere • biosphere

7. Macrohabitat analysis • Temporal information • date • time • observers’ names • Spatial information • specific location, GPS coordinates • topography • drainage characteristics, watershed area

8. Macrohabitat analysis • Lithosphere • general land forms • natural • anthropogenic • soil types • grain size analysis (%sand, %silt, %clay + organic) • Soil Conservation Service area maps • Munsell Soil Color Charts

9. Macrohabitat analysis • Some principal land forms • Table 2A.1 • coastal • delta • coastal plain • outwash • dune • spit • reef • beach • bar • tidal flat • barrier island • swale

10. Macrohabitat analysis • Atmosphere • measured variables • wind: speed and direction • percent cloud cover • general weather • air temperature • relative humidity • barometric pressure • climate

13. Macrohabitat analysis • Community type • Zonation: horizontal patterns • Stratification: vertical patterns

15. Stratification

16. Stratification

17. Macrohabitat analysis • Habitat diversity • habitat richness: number of different habitats present • habitat heterogeneity versus dominance

18. Analysis of aquatic habitats • Habitat type • marine • estuarine • freshwater • Communities based on salinity gradients • euryhaline • stenohaline

19. Limnology: freshwater • Lentic systems • calm, slow or non-moving • lakes and ponds • oligotrophic • eutrophic • mesotrophic • hypereutrophic

20. Limnology: freshwater • Lentic systems • wetlands • marsh • swamp or slough • bog • pothole or playa lake • bottomland hardwood

21. Limnology: freshwater • Lentic systems • zonation • littoral zone (shallow, shoreline) • open water • euphotic zone • compensation depth • aphotic zone

22. Limnology: freshwater • Lotic systems • moving • rivers, streams, creeks, bayous • riparian habitats

23. Water use categories • Aquatic life • parameters designed to protect aquatic species • e.g., dissolved oxygen, nutrients, toxics • Contact recreation • relative risk to humans from swimming and other water sports

24. Water use categories • Public water supply • indicators used to evaluate water source for public water systems • e.g., nutrients, toxics • Fish consumption • indicators for fish health or disease • toxic chemicals contained in fish tissue

25. Water quality standards • Used by EPA / TCEQ to evaluate condition of water and establish limits on permitted dischargers • Numeric standards • values specific to segments • Narrative standards • protect aesthetics and designated uses • overall screening limits • not segment specific

26. Physical variables in aquatic habitats • Water temperature • temperature profile • temperature stratification • epilimnion / hypolimnion • thermocline • biological effects • reaction rates • migration / reproductive cues • physiological tolerances

28. Physical variables in aquatic habitats • Turbidity • light scatter or penetration in water • dependent on • dissolved chemicals • suspended particulates • microbes and algae

29. Physical variables in aquatic habitats • Turbidity • sources • colloidal rock particles • eroded soil • domestic and industrial wastewater • street washings • environmental significance • aesthetics • photosynthesis

30. Physical variables in aquatic habitats • Turbidity • measurement • Jackson Turbidity Unit (JTU) • nephelometer turbidity units • Formazin Attenuation Units (FAU) • Secchi disk depth

31. Physical variables in aquatic habitats • Color • sources • decomposition of lignin  tannins, humic acid, humates • pollutants • apparent color (Pt-Co units) • true color

32. Physical variables in aquatic habitats • Conductivity (specific conductance) • measure of how well water can conduct an electrical current • dependent on ion concentration in water • indirect measure of salinity and other salts • measured in mmhos, µmhos, mS, µS

33. Chemical analyses • Dissolved oxygen (DO) • essential for life processes of most aquatic organisms • low DO often results from high organic matter loads or low flow • excessive DO often results from excess plant production

34. Chemical analyses • Dissolved oxygen (DO) • DO in warm water versus cold water • effect of salinity • percent saturation

36. Chemical analyses • Dissolved oxygen (DO) • State of Texas Surface Water Quality Standards for DO 24-hr mean concentration Absolute minimum Exceptional 6 mg/L 5 mg/L High 5 mg/L 4 mg/L Intermediate 4 mg/L 3 mg/L Limited 3 mg/L 2 mg/L No significant DO 2 mg/L 1.5 mg/L

37. Chemical analyses • pH • general indicator of water quality in neutral range (pH 6-8.5) • major factor affecting most chemical and biological reactions

38. Chemical analyses • Alkalinity and CO2 • measure of buffering capacity of water • sources of alkalinity • hydroxides • carbonates • bicarbonates

40. Chemical analyses • Hardness • geographic variation in natural water hardness • hardness classifications mg/L degree of hardness 0-75 soft 75-150 moderately hard 150-300 hard >300 very hard

42. Chemical analyses • Hardness • caused by divalent metal cations

44. Chemical analyses • Hardness • total hardness • calcium hardness • magnesium hardness

45. Chemical analyses • Nitrogen • role as nutrient versus pollutant • forms • organic • nitrate TX screening level = 2.76 mg/L • nitrite • ammonia: TX screening = 0.17 mg/L

47. Chemical analyses • Phosphate • role as nutrient versus pollutant • TX screening level (orthophosphate P) = 0.5 mg/L

48. Chemical analyses • Other water chemistry parameters • trace metals / sulfate / tannins and lignins • gases: carbon dioxide, hydrogen sulfide • BOD • measure of oxygen demanding bacterial composition of water • measures oxygen consumption by aerobic microorganisms as they decompose organic material present in water

49. Biological components • Phytoplankton • Periphyton • Zooplankton • Nekton