Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Geog319RmSns > Vegetation > Flashcards

Vegetation Flashcards

1
Q

What are the spectral curves of different material dependent upon?

A
  • Reflection, Absorption, and Transmittance of their constituents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a general guide for image processes?

A
  • DN
  • Calibration
  • Correction
  • Reflectance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many visual cones do humans have?

A

3 (visible range)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many visual cones to butterflies have?

A

5 (Visible, UV and Violet)

- UV spectrum may be used for mating purposes (wings look attractive etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the difference between human and butterfly vision?

A
  • Butterflies see more cones and into UV spectrum
  • Butterflies have ‘narrower bands’
  • Narrow is generally better
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mantis shrimp

A
  • Extraordinary vision
  • Approximately 16 visual cones
  • Many narrow bands in the visual range
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What can knowledge about variations in species and vegetation distribution patterns, vegetation growth cycles, and plant physiology and morphology provide insight into?

A
  • Climatic, geologic, and physiographic characteristics of a region
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Total incident irradiation = ?

A

Total Reflected plus Total Absorbed plus Total Transmitted

- Depending on spectrum, light will be 1 of these 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does light reach the understory?

A
  • Transmittance through leaves of canopy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the potential fates of EM radiation absorbed by a pigment?

A
  • Usually blue and red absorbed:
  • Dissipated as heat
  • Emitted in longer wavelength (fluorescence)
  • Used for photosynthesis (trigger chemical reaction)
  • Depends on amount of energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the general chemical eqn for photosynthesis?

A

6 Carbon Dioxides plus 6 waters plus light energy (PAR spectra) = Carbohydrate (sugar, c6H12O6) plus 6 Oxygens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does PAR stand for?

A

Photosynthetically Active Radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is PAR?

A
  • Spectral range 400 - 700nm that organisms can use for photosynth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is the spectral range for PAR the way it is?

A
  • Photons at shorter wavelength too energetic and damage cells and absorbed by atmospheric ozone
  • Longer Photons don’t have enough energy to fuel photosynth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Plant cuticle

A
  • 1st layer
  • Holds water on surface
  • Regulates light
  • But doesn’t play much role
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Stoma (Stomata)

A
  • Hole on bottom of leaf that releases carbon dioxide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Parenchyma

A
  • 2nd layer
  • Holds chlorophyl in chloroplasts
  • Absorbs light (red and blue)
  • Unabsorbed transmits to spongy mesophyll
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Chloroplasts and Granum

A
  • Found in Parenchyma and spongy parenchyma mesophyll
  • Where light reaction occurs
  • Absorb red and blue light
  • Granum (stack of thylakoids) in chloroplast has chlorophyl and pigments, where photosynth begins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 7 main factors that affect leaf optical properties?

A
  • Pigment composition
  • Internal and external leaf structure
  • Water content
  • Age
  • Nutrient Stress
  • Healthiness
  • Background
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the dominant factor controlling leaf reflectance?

A
  • Leaf pigments in the palisade mesophyll:
  • Chlorophyll a and b
  • Beta carotene etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What wavelengths does chlorophyl a absorb?

A

0.43 and 0.66

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What wavelengths does chlorophyl b absorb?

A

0.45 and 0.65

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the overall perception of transmitted wavelengths after chlorophyl a and b has absorbed their corresponding wavelengths?

A
  • Overall green perception

- Lack of absorption in the 0.5 to about 0.6 range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Carotene

A
  1. 35 to 0.5 micrometers

- Transmits/reflects orange colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Phycoerythrin

A
  1. 55 micrometers

- Transmits/reflects red with a bit of purple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Phycocyanin

A
  1. 6 micrometers

- Transmits/reflects bluish-green (cyan)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Xantophyll

A
  1. 35 to 0.5

- Transmits/reflects yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does pigmentation depend on?

A
  • Seasonal senescence

- Environmental stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does a green leaf represent? Yellow? Red? Brown?

A 
G = Photosynthesizing, 
Y = Beginning of senescence
R = Late stage senescence
B = Fallen, dieing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens to the spectral response as a leaf dies?

A
  • Less chlorophyl absorption at 0.43 and0.66 micrometers

- Blue shift of the red edge from just above 700nm to just below 700nm

31
Q

What are the ranges that indicate stress?

A

535 - 640nm and 685 - 700nm

32
Q

Blue shift of the red edge

A
  • Red edge = sharp increase from red to NIR reflectance

- As pigmentation changes the sharp edge shits towards blue range

33
Q

Can the blue shift be detected on Landsat 7, 8, or Sentinel-2?

A

Might not be able to see with Sentinel-2 b/c red band is very narrow
- Landsat 8 might be best with a larger red band?

34
Q

What happens in the spongy mesophyll?

A
  • NIR energy interaction
  • High reflectance at 0.7 to 1.4 micrometers b/c of internal scattering at the cell wall-air interfaces within the leaf (high NIR)
  • Refractive index (n) - hydrated cells: 1.4
  • Intracellular air: n = 1.0003
35
Q

Healthy mature leaves…?

A
  • Absorb radiation very efficiently in blue and red

- Chlorophyll a = photosynthesis

36
Q

Why do plants have high reflectance and transmittance in the NIR? i.e. low absorption

A
  • If NIR was absorbed as efficiently as visible plant would be too warm and proteins denatured
  • Evolutionary adaptation of spongy mesophyll allow most NIR to reflect or transmit
37
Q

Why is the scattering in NIR possible and satellite bands important to be in that location?

A
  • Less atmospheric water absorption in those wavelengths/bands
38
Q

What are the generalized interactions of blue, red, and NIR light with plant tissue of young, mature, and old leaf?

A
  • Young: G and IR reflected, R and B absorbed
  • Mature: G reflected, R and B absorbed, More scattering of IR as spongy mesophyll has more air spaces
  • Old/senesced: B, R, G, and IR reflected, spongy mesophyll broken down
39
Q

What is the spectral behaviour of vegetation at the leaf level mostly dependent on?

A
  • Visible range (400 - 700nm): Absorption of chlorophyll a (430 and 660) and chlorophyl b (450 and 650), green colour from chlorophyl not absorbing green light
  • NIR (700-1200nm): Cell structure and interstitial air spaces (index of refraction) act to scatter radiation, prevents heat damage
  • MIR (1200-2700nm): Plant water content, strong absorption bands at 1450 and 1940nm
40
Q

MIR

A

1.3 - 2.5 micrometers

41
Q

Water conditions: turgid vs. relatively turgid

A
  • Turgid = high water content
  • Relatively turgid = low water content
  • More water content = more IR absorption
  • Less water content = More reflection
42
Q

Water absorption bands (nm)

A
  • 970
  • 1190
  • 1450
  • 1780
  • 1940
  • 2700
43
Q

Why are landsat bands 6 and 7 located where they are?

A
  • Because that is where interactions with MIR and leaf water content occur
  • Atmospheric window where wavelengths are not absorbed by atmospheric water
44
Q

Plant response to parasites

A
  • Change in pigments (visible)
  • Necrosis: NIR
  • Water content: NIR, SWIR
  • Parasites in the intercellular spaces therefore compacts the internal structures, NIR
45
Q

Plant response to fungus

A
  • Loses chlorophyll pigments (visible)

- Water content, NIR, SWIR

46
Q

What do insect vectors do?

A
  • Carry fungus from infected to healthy trees

- Fungus blocks the water translocation

47
Q

What does a mountain pine beetle do?

A
  • Blocks water translocation
48
Q

Beetle infestation: Endemic

A

A few trees, isolated

49
Q

Beetle infestation: Incipient

A

A stand of trees infected, at least a few dozen

50
Q

Beetle infestation: Outbreak

A

Entire stands of forest infected, large areas

51
Q

Why is there an increase in MIR reflection when a plant is infected with fungus?

A
  • Less water is absorbing in the leaves
52
Q

Why is remote sensing a good option for monitoring mountain pine beetle infestation?

A
  • Tree can still look fine in visible range
  • But early, green, attack stage shows very decreased IR absorbance
  • Red attack is late stage and only then can damage bee seen by eye
53
Q

General vegetation senescence

A
  • NIR begins to decrease

- Red reflection increases b/c no longer absorbing chlorophyll

54
Q

Advantages of handheld spectral radiometer? Disadvantage?

A
  • Achieve ideal curves
  • Separate desiccated mixed with healthy veg
  • No atm. involved
  • No pixel mixing
  • Not as good spatial and spectral resolution
55
Q

What are possible causes for the blue shift of the red edge?

A
  • Natural senescence
  • Water deficiency
  • Toxic materials
  • Disease
  • Decrease chlorophyl a and the red absorption shifts to shorter wavelength and width of absorption band decreases
56
Q

Vegetation index

A
  • Indicator of relative abundance and activity of green vegetation
  • Dimensionless
  • Radiometric measures that function as indicators
57
Q

What does the vegetation index indicate

A
  • Leaf-area index
  • Precent green cover
  • Chlorophyll content
  • Green biomass
58
Q

Advantages of Vegetation index

A
  • Minimize effects of atmosphere

- Normalize canopy background and topography

59
Q

LAI

A

Leaf-Area Index

  • Amount of vegetation
  • Function of Simple Ratio
60
Q

Simple Ratio

A

= NIR/R

  • NIR represents vegetation
  • R represents soil reflectance and chlorophyll absorption
  • Looks at vegetation present and LAI
61
Q

High LAI (biomass) = what SR?

A
  • High SR, lots of vegetation

- Senesced would be much smaller than healthy veg

62
Q

Problems with SR

A
  • Unitless w/ no range
  • Depends on digital number in image being worked with therefore is image dependent
  • Cannot compare output on 2 different scales
  • Only usable for 1 image and cannot compare images, especially 8 vs. 16 bit
63
Q

NDVI

A
  • Normal Distribution Vegetation Index
  • Normalized SR into 0 - 1 range
    = NIR - R/NIR plus R
  • Good indicator of a good growing year for healthy veg
  • Increase in NDVI = Increased biomass
64
Q

What is the difference for healthy and unhealthy veg relating to the NDVI

A
  • Healthy absorbs most visible and reflects large portion of NIR, high NDVI
  • Unhealthy/sparse reflects more visible and less NIR, low NDVI
65
Q

Applications of NDVI

A
  • Growing seasons (compare years) health/yield in subsaharan Africa
  • Drought in California (compare years)
  • Input for global carbon models, LAI APAR percent cover biomass
66
Q

Problems with NDVI

A
  • Saturation
  • Soil colour
  • Moisture content
  • Atmospheric content
  • Atmospheric conditions
  • Presence of dead material in canopy
  • All the above change regionally and/or seasonally
67
Q

Why is soil colour a problem for NDVI?

A
  • If soil shows and depending on type (brown vs red-iron rich) gives a different signal
68
Q

How does presence of dead material affect NDVI?

A
  • NDVI can see a dead branch but cannot detect that it isn’t affecting the plant and that the plant is still healthy
69
Q

How can problems with the NDVI be fixed?

A
  • Soil adjustments

- Blue band for atmospheric normalization

70
Q

SARVI

A

Soil and Atmosphere Resistant Vegetation Index
- Soil calibration factor uses the blue channel
= 2(densityNIR - densityR)/(L plus densityNIR plus C1densityR - C2densityBlue)

71
Q

Relationship between vegetation and soil during growing season for SR

A
  • Planted, watered moist soil, no veg yet, low red
  • Intermetiate biomass/canopy closure less red and more NIR, moves up centre of shark fin graph
  • Almost ripe is closer to peak, more NIR, less R
  • Ripe/high canopy closure/biomass is peak, high NIR, less R
  • Harvested is back to soil line but more R b/c not moist, no longer watered
72
Q

In false colour, what does results in cyan?

A
  • Green plus red

- Closer to bare soil

73
Q

Leaf additive reflection

A
  • Leaf reflects 40 - 60 percent incident NIR from spongy mesphyll
  • Transmits remaining 45 - 50 percent through to layer below
  • Transmitted can then be reflected once again by leaves in lower canopy
  • More leaves in the canopy means more NIR reflectance

Geog319RmSns (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions