1 / 61

Advanced Plant Sampling Techniques: The Sequel

Dive into the importance of sampling methods in ecology with a focus on plant species evaluation. Learn about density, frequency, cover, and how to calculate relative values using plotless distance methods like quadrat and belt transect. Understand the significance of random point placement and correct density calculations. Discover soil components, weathering factors, texture classification, and the role of organic matter in soil structure. Enhance your knowledge of plant sampling methods and soil characteristics for ecological research.

hunterk
Download Presentation

Advanced Plant Sampling Techniques: The Sequel

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. Sampling TechniquesTHE SEQUEL

  2. Warning! • Material included on Lecture Exam #1!

  3. Importance • Which plants “important?” • Measures importance (sp. A) • Density of A = No. inds. per unit area (reflects abundance A) • Frequency of A = No. times sp. A in samples divided by total samples taken (reflects pattern A) • Cover of A = Area occupied by A (reflects biomass A)

  4. Methods • 1) Quadrat • 2) Belt transect • 3) Line intercept • 4) Plotless (distance) methods

  5. Plotless (distance) methods • Based on points (0 dimensional method) • Often trees along transect

  6. Plotless (distance) methods • Collect: • 1) tree ID • 2) tree size (reflects biomass/cover) • 3) distance measurement (from something to something)

  7. Plotless (distance) methods • Method 1: Nearest individual method

  8. Plotless (distance) methods • Method 2: Nearest neighbor method

  9. Plotless (distance) methods • Method 3: Point centered quarter method

  10. Plotless (distance) methods • Information Collected: • 1) tree ID • 2) tree size (reflects biomass/cover) • 3) distance measurement (from something to something) • IV= Rel. density + Rel. frequency + Rel. cover • <300%= <100% + < 100% + < 100% • How get rel. density, rel. frequency, rel. cover values?

  11. Plotless (distance) methods • Cover: have DBH • Convert DBH to area trunk each species

  12. Plotless (distance) methods • Cover: have DBH • Convert DBH to area trunk each species • % rel. cover species Y: • Cover Y/Cover all species X 100% • IV= Rel. density + Rel. frequency + Rel. cover

  13. Plotless (distance) methods • Frequency: tree identities each point • % frequency species Y: • No. pts. with species Y/Total number pts. X 100% • % rel. freq. sp. Y: • Freq. Y/Freq. all species X 100% • IV= Rel. density + Rel. frequency + Rel. cover

  14. Plotless (distance) methods • Density: ?? No areas measured?? • Geometric principle: as density increases distances measured decrease • Note importance random placement points!

  15. Plotless (distance) methods • Steps: • 1) Calc. mean distance (D) for all trees sampled • 2) Use formula: • Density (all species) = A/(correction factor)(D)2 • For metric units: • A=10,000 m2/hectare (ha) • D in meters (m) • Correction factor?

  16. Plotless (distance) methods • Steps: • Correction factor? • 2 nearest individual method • 1.67 nearest neighbor method • 1 point centered quarter method

  17. Plotless (distance) methods • Steps: • Correction factor? • 2 for nearest individual method • 1.67 for nearest neighbor method • 1 for point centered quarter method • 3) Calc. density species Y: • No. Y/No. all species X Density (all species) • 4) % rel. density Y: • Density Y/Density all species X 100%

  18. Plotless (distance) methods • IV species Y • IV= Rel. density + Rel. frequency + Rel. cover • <300%= <100% + < 100% + < 100% • Repeat calcs. other species

  19. Plotless (distance) methods • Point Centered Quarter method: • 1) More data/point • 2) Relatively simple • 3) No correction factor in density formula (correction factor = 1)

  20. How place sample units? • Generally, random best • Define? • All potential samples have equal chance inclusion • Why best? • Eliminate bias • May be required: statistics/equations (e.g., density formula for plotless methods)

  21. How place sample units? • Random not same as: • Arbitrary: Attempt eliminate conscious bias • Systematic: Use numeric pattern (ex, every 5th tree) • Deliberate: Choose with criteria (ex, all trees > 30 cm dbh)

  22. How place sample units? • Random not alwaysrepresentative sample • Ex: X X X X X X X X X X X

  23. How place sample units? • Techniques: • Random • vs. • Stratified random (subdivide area & sample randomly in each division)

  24. How place sample units? • Techniques: • Systematic

  25. How place sample units? • Techniques: • Random-Systematic (start random, place points systematically: or vice versa) systematic random systematic random OR

  26. Ch. 4: Soils, Nutrition etc.

  27. Soil • Definition: • Natural body: layers (horizons)

  28. Soil • Definition: • Natural body: layers (horizons) • Mineral + organic matter (OM) • Differs from parent material: substance from which soil derived

  29. Weathering Factors • Mineral component: generated by weathering rock

  30. Soil Texture A: Sand & silt know these • Major particle sizes (know these) B: clays

  31. Textural triangle • Distribution particles by size class: texture • Loam: mix sand, silt, clay • Texture important: fertility, water availability

  32. Soil Structure • Particles form peds • Affect water + root penetration How important??

  33. Organic matter (OM) • Humus: partly decomposed OM • Negatively charged: • carboxyl groups (-COOH) • phenols

  34. Soil Horizons

  35. Soil Horizons • Vertical gradients • Leaching: wash material upper to lower layers • Weathering: great at surface • Biotic effects: great at surface

  36. Soil Horizons • Major horizons: • O: organic matter (surface) • A: surface soil. High organic matter • E: leaching strong

  37. Soil Horizons • Major horizons: • B: subsurface soil. • Deposition • Chemical changes (secondary minerals/clays)

  38. Soil Horizons • Major horizons: • B: subsurface soil. • Hardpan: cemented soil grains • Claypan: dense clay • Both: interfere water penetration, roots • Humic layer: organic matter from E

  39. Soil Horizons • Major horizons: • C: weathered parent material • R: unweathered parent material

  40. Soil Horizons • Layers subdivided (numbers) Fig. 4.5

  41. Organisms • Plants influence soil & vice versa • How? • 1) Roots • Depth: record 394 ft: fig tree (Echo Caves, South Africa) • Amount (biomass/unit volume/yr) • Size: woody (shrub/tree) vs. fibrous (grasses)

  42. Organisms • How plants influence soil? • 2) Base cycling • Nutrients “in play”

  43. Organisms • Fertile island effect: under desert shrubs soil fertile • Ex, creosote bush: under shrubs--more nutrients

  44. Organisms • How plants influence soil? • 3) Litter acidity • Ex: soils under spruce (conifer) vs hardwood

  45. Parent Material • Within climate, parent material major influence • Ex, serpentine soil • High Mg, low Ca • Lots Ni, Cr

  46. Parent Material • Extreme cases, serpentine “barrens”

  47. Parent Material Forest on granite in Australia • Within climate, parent material major influence • Ex, granite outcrop soil • Lots sand (coarse texture) • Soil dry (water drains)

  48. Time • General trends (as time increases): • pH decreases • organic matter increases • clay increases • depth increases

  49. Soil Fertility • Defn.: Ability soil hold & deliver nutrients • Determined by texture, organic matter, pH Holding soil….

  50. Soil Fertility • Texture: clays • Negative charge: hold useful cations (Ca++, K+, Mg++, Zn++) • Huge surface

More Related