Chapter 4: Forest Ecophysiology Flashcards
1
Q
What two disciplines does ecophysiology combine?
A
Physiology and ecology
2
Q
What is the main focus of ecophysiology?
A
Whole-organism function
3
Q
What does ecophysiology address evolutionarily?
A
Adaptations to specific environments
4
Q
What are six areas of focus in ecophysiology?
A
Thermoregulation, energetics, nutrition, gas exchange, water/osmotic balance, stress responses
5
Q
What are two ways that ecophysiology extends beyond organism level?
A
By modeling ecosystem behavior and predicting human impacts
6
Q
What are three examples of elements of tree anatomy?
A
Structure/function of leaves, stems, roots
7
Q
What are two examples of elements of tree physiology?
A
Seasonal responses and stress/resource availability responses
8
Q
Leaves fix radiant energy to this
A
Chemical form
9
Q
What are the raw materials of photosynthesis?
A
CO2 and H2O
10
Q
What is the glucose product of photosynthesis stored as?
A
Sucrose and starch
11
Q
This photosynthesis byproduct is essential for life
A
Oxygen
12
Q
Photosynthesis reactions occur in this part of the leaf
A
Mesophyll
13
Q
Mesophyll cells contain these for photosynthesis
A
Chloroplasts
14
Q
Chloroplasts contain these pigments
A
Chlorophyll
15
Q
What are the two wavelengths of visible light that chlorophyll absorbs the most?
A
Blue (400-500nm) and red (600-700nm)
16
Q
In photosynthesis, absorbed light drives this process
A
Sugar synthesis
17
Q
These structures in leaves regulate gas exchange
A
Stomata
18
Q
This gas enters the leaf via stomata
A
CO2
19
Q
This enzyme fixes CO2 into acid form
A
Rubisco
20
Q
Carbon exits the leaf as this
A
Glucose (C6H12O6)
21
Q
What leaf structure does carbon exit as glucose?
A
Vein
22
Q
Mesophyll must be this in order for photosynthesis to occur
A
Saturated
23
Q
H2O enters the leaf as liquid via these
A
Leaf veins
24
Q
In what form does H2O exit leaves through the stomata?
A
Vapor
25
What is the process of leaf vapor exiting leaves through stomata called?
Transpiration
26
What two functions does transpiration serve?
Pulling water up from roots and cooling hot leaves.
27
These are cells that surround the apertures of stomates and can open and close
Guard cells
28
What 4 stimuli do guard cells respond to?
Light, humidity, CO2, root hormones
29
Stomata must be this in order to allow CO2 into leaf and to pull water up from soil
Open
30
Is the water gradient across stomata usually greater than the CO2 gradient?
Yes
31
Can open stomata lead to high water losses?
Yes
32
What percent of water taken up through plants is transpired?
90%
33
In what type of environment are stomata tightly controlled?
Dry environments
34
Are outer, exposed leaves more sinused than inner leaves?
Yes
35
Leaves in cooler, temperate environments have this type of leaf margin
Toothed
36
Leaves in warmer, tropical sites have this type of leaf margin
Entire
37
Primary forest leaves have this type of leaf margin
Entire
38
Secondary forest leaves have this type of leaf margin
Toothed
39
To reduce wind damage, larger leaves are often this
Compound
40
Does leaf size decrease with increased moisture and fertility?
No
41
Does leaf size decrease with increasing light and elevation?
Yes
42
Does leaf thickness increase with decreasing rain?
Yes
43
Does leaf thickness increase with increasing light and elevation?
No
44
Do smaller leaves tend to be simple leaves?
Yes
45
What are two characteristics of stomata in dry climates?
Recessed and fewer
46
Do sun leaves typically have less area?
Yes
47
Do sun leaves typically have shallower sinuses?
No
48
Do sun leaves typically have greater thickness?
Yes
49
Do sun leaves typically have shorter palisade cells?
No
50
Do sun leaves typically have more stomates?
No
51
Do sun leaves typically have more rubisco?
Yes
52
Do shade leaves typically have less area?
No
53
Do shade leaves typically have greater thickness?
No
54
Do shade leaves typically have reduced sinuses?
Yes
55
Do shade leaves typically have greater chlorophyll concentration?
Yes
56
Do shade leaves typically have more stomates?
Yes
57
What type of chlorophyll do shade leaves have more of?
Chlorophyll B
58
What wavelength of light are shade leaves adapted to absorbing?
Blue
59
On trees, a trunk is also known as this
Bole
60
This is lignified xylem vessels
Wood
61
This is a tough polymer of cell walls
Lignin
62
What two things does lignin provide?
Strength and decay resistance
63
Most of a tree is this type of cells
Dead cells
64
What are the two types of wood in boles?
Heartwood and sapwood
65
This type of wood is a core of dead xylem cells infused with resins and oils
Heartwood
66
What two things do resins protect wood against?
Decay and insects
67
What two properties do resins give to wood?
Color and odor
68
This type of wood is a cylinder of living cells around the heartwood
Sapwood
69
What two types of vascular tissue make up sapwood?
Xylem and phloem
70
What is the purpose of xylem?
To conduct water from roots to leaves
71
Gymnosperms have only this type of xylem cells
Tracheids
72
What two types of xylem cells do angiosperms have?
Vessels and tracheids
73
What is the purpose of phloem?
To conduct photosynthesized sugars away from leaves
74
What type of phloem cells do gymnosperms have?
Sieve cells
75
What type of phloem cells do angiosperms have?
Sieve tubes
76
These are plant tissues associated with growth
Meristems
77
These meristems are located at the tip of a stem/branch
Apical meristems
78
What type of growth do apical meristems create?
Longitudinal
79
What is another name for longitudinal growth in plants?
Primary growth
80
What plant organ do apical meristems create?
New buds/leaves
81
These are apical meristems found on stem/root tips
Stem meristems
82
These stem meristems form thin cylinders of dividing cells around stems/branches
Lateral meristems
83
What type of growth do lateral meristems create?
Secondary growth
84
What are the two types of cambium in lateral meristems?
Vascular and cork cambium
85
What does vascular cambium give rise to?
Vascular tissues
86
In vascular cambium, which way does xylem grow?
Inward
87
In vascular cambium, which way does phloem grow?
Outward
88
Where is cork cambium found?
Outside vascular cambium
89
What two types of tissue does cork cambium produce?
Cork and bark
90
What are two functions of bark?
Water conservation and protection
91
Lateral growth of woody tissues creates these
Growth rings
92
Growth rings occur in regions with these
Distinct growing seasons
93
This type of wood growth represents periods of rapid lateral growth
Earlywood
94
What is another name for earlywood?
Spring wood
95
This type of wood growth represents periods of slowed lateral growth
Latewood
96
What does latewood contain high concentrations of?
Resins
97
What is another name for latewood?
Summer wood
98
Are earlywood or latewood growth bands wider and lighter in color?
Earlywood
99
Are earlywood or latewood growth bands narrower and darker in color?
Latewood
100
This is the study of tree rings to date periods of time
Dendrochronology
101
What are the two types of tree form?
Excurrent and decurrent
102
What are five physical characteristics of excurrent trees?
Trunk continuous to the top; Many small lateral branches; Slender silhouette; Multi-layered canopy; Regular-spaced large leaves
103
What are four physical characteristics of decurrent trees?
Trunk split into lateral branches; Umbrella-shaped silhouette; Monolayer canopy; Regular-spaced large leaves
104
Which tree form is more shade tolerant and common in late succession?
Decurrent
105
Which tree form performs better in open environments?
Excurrent
106
What are the two types of tree roots?
Woody and non-woody
107
What are three physical characteristics of woody roots?
Large, perennial, have growth rings
108
What are two functions of woody roots?
Provide root system framework/support and carb storage
109
What are three physical characteristics of non-woody roots?
Small, fleshy/pliable/soft, and have root hairs
110
What are two other terms for non-woody roots?
Feeder or fine roots
111
What is the function of non-woody roots?
Water/nutrient uptake
112
Where are most non-woody roots found in the soil?
Upper few inches of soil
113
These meristems are tissues of cell growth at root tip
Root apical meristems
114
This protects the root apical meristem
Root cap
115
What are the three zones of root tips?
Zone of division, zone of elongation, zone of differentiation/maturation
116
This root tip zone is where newly formed cells grow in length
Zone of elongation
117
This root tip zone is where secondary walls form and root hairs develop
Zone of differentiation/maturation
118
This root tip zone is a region of meristematic tissue with rapidly dividng cells
Zone of division
119
These are extensions of root epidermis that develop in the zone of differentiation
Root hairs
120
What is the function of root hairs?
To increase surface are for water/mineral absorption
121
How long do root hairs survive?
2-3 weeks
122
This is a thin cylinder of dividing cells around all roots
Vascular cambium
123
Vascular cambium arises from this thin tissue layer in roots
Pericycle
124
What are three things produced by the vascular cambium in roots?
Xylem, phloem, side roots
125
This is the vascular cylinder in root meristems
Stele
126
What are three types of root systems?
Tap root, heart root, flat root
127
In this root system, one large central root extends down from main trunk, with lateral roots extending from it
Tap root
128
What are three examples of trees with tap root systems?
Hickory, walnut, white oak
129
In this root system, multiple primary roots extend laterally from the trunk, attach to numerous secondary roots, and grow mostly horizontally
Heart root
130
What are three examples of trees with heart root systems?
Red oak, sycamore, pines
131
In this root system, obvious primary roots are lacking, and roots grow and spread laterally
Flat root
132
What are four examples of trees with flat root systems?
Birch, spruce, maple, cottonwood
133
What are two common myths about tree roots?
That roots grow deep and do not extend past drip line
134
What are five environmental challenges that trees respond to?
Seasonal variations in climate; Chronic resource shortages; Variation in resource availability; Climate change; Changes in atmospheric chemistry
135
What are three ways trees respond to warm-cold seasonal variations?
Deciduousness, cold hardiness, and changes in cell chemistry
136
Why do trees drop leaves?
To conserve water
137
What are three changes tree cells make in response to warm-cold seasonal variation?
Losing water, gaining sugar, changing proteins
138
What are two cues for trees to adapt to warm-cold seasonal variation?
Light and temperature
139
This adaptation to seasonal variation decreases a plant's lethal temperature over the winter, and is reversed with onset of spring
Cold hardiness
140
What are three adaptations of trees to wet-dry seasonal variation?
Deciduousness, photosynthetic bark, water storage tissues recharge
141
What are three adaptations of trees to chronic light shortage?
Leaf form/biochemistry plasticity; Adventitious buds that break in presence of light; Slow growth
142
What are two types of variation in water availability that affect trees?
Drought and flood anoxia
143
What are four tree responses to drought?
Stomata closure from the release of root hormones in dry soils; Deep taproots; Cells become more hypertonic to draw in water; Early leaf drop
144
What are two tree responses to flood anoxia?
Switching to fermentation; aerial roots from stem
145
How will many tree species have to respond to climate change (2 degree C rise by 2100)?
Shift range 200 miles north
146
What will a 200 mile north range shift require species to do?
Disperse 1-3 miles per year
147
Which type of forests are most at risk from climate change?
Cool northern forests
148
If climate change is slow, what will happen to cool northern forests?
They will be displaced by southern species
149
If climate change is rapid, what will happen to cool northern forests?
They will be replaced by grasslands
150
What are three other examples of forest types that are at risk from climate change?
Maple-beech, aspen-birch, spruce-fir
151
What are four risks that will rise with climate change?
Fire, drought, pests, diseases
152
By what percentage may burned areas increase with climate change?
25-50%
153
In some forests, modest temperature increases may raise this
NPP
154
More extreme temperature increases will do this to NPP
Reduce
155
Higher NPP from climate change will reduce this
Stream flow
156
More disturbance caused by climate change will reduce this
Water quality
157
What are three tree responses to higher CO2?
Rise in NPP; Rise in optimal growth temperatures; Reduced water loss
158
Are trees C3 or C4 plants?
C3
159
What is NOx found in?
Fossil fuel emissions
160
This acts as a fertilizer and may boost NPP
Nitrogen deposition
161
NOx does this to soil
Acidification
162
What are three things that happen due to soil acidification?
Nutrients leach; Toxic elements loosen; Microbial activity is reduced
163
This rises with warmer temperatures
Ground-level ozone
164
This is a strong oxidant that kills tissue and stunts plant growth
Ozone
