Ubc Frst 201 Final

Front 1

Succession

Back 1

ecosystems constantly changing, disturbed
-never in equilibrium with current environment

temporal patterns that occur in ecosystems differ with scale of observation & severity of disturbance

Front 2

Ecological Succession

Back 2

process of ecosystem development
-can result from developmental changes in ecosystem itself or from disturbances

Front 3

Sere

Back 3

characteristic sequence of biotic communities that follow another in a particular environment

Front 4

seral stages

Back 4

various communities that together make up a sere,
each is floristically distinct

Front 5

Autogenic succession

Back 5

*most common
resident organisms change physical environment

Front 6

allogenic succession

Back 6

geological processes cause change

Front 7

biogenic succession

Back 7

sudden interference by living organisms (herbivore, pathogen)

Front 8

primary succession

Back 8

occurs on newly exposed land
-initiated by disturbance that exposes substrates and are left with essentially no plant growth at start
-sever disturbances
-glaciations, volcanic ash deposition, catastrophic wildfire

Front 9

secondary succession

Back 9

occurs when vegetation is cleared but soil remains
-can start in mid-succession and then to final climax
-moderate disturbances
-after wildfire, wind, logging

Front 10

succession results in

Back 10

"a rich, dynamic tapestry of vegetation, providing an array of habitats for animals and microbes"
-Perry, 1994

Front 11

Relay Floristics

Back 11

-concept of seral stages
-each stage prepares habitat for the next one, often through changes to soil.
3 steps:
-primary succession colonizers
-secondary succession colonizers
-late successional species

Front 12

Pioneer community traits

Back 12

harsh environment
increasing biomass
some loss of nutrients
fluctuations
low diversity
energy consumption inefficient
r-adapted (energy into reproduction, rapid growth)

Front 13

climax community traits

Back 13

moderate environment
nutrient cycling
high diversity
energy consumption efficient
fluctuations rare
biomass stable
K-adapted (energy into biomass not reproduction)

Front 14

shade tolerance
-Tolerant (T)
-Intolerant (I)
Intermediate (N)

Back 14

ability of a tree to grow in the shade of other trees
T = grow well in low light, do not show large increase with increasing light lvls. Climax species.
I = cannot grow well in low light, grow very well in high light. Pioneer species
N = intermediate in ability to grow in the shade

Front 15

progressive succession

Back 15

shows increase in biomass, diversity and structural complexity
-trend towards being a mesic site

Front 16

retrogressive succession

Back 16

shows decrease in biomass and diversity
-trend towards becoming a hydric or xeric site

Front 17

paludification

Back 17

process of mire (peat forming ecosystem) formation in an area that used to be forested or a grassland
-autogenic or climatic processes leading to waterlogging and anaerobicity

Front 18

carbon dynamics in primary succession

Back 18

initially: low O.M. content, CEC, moisture holding capacity, decomposition
mid succession: rapid decomp., increases in soil carbon and nutrient inputs
late succession: decomp. slows, reduced rates of soil carbon & nutrient inputs

Front 19

Carbon pools & Primary succession

Back 19

increases then plateaus
C-Flux, Early: NPP & NEP increases as O.M. increases; heterotrophic resp. lags NPP.
C-Flux, Late: NPP = heterotrophic resp; NEP declines to zero. Eventually NEP affected by climate & gap phase disturbances

Front 20

Carbon pools & secondary succession

Back 20

initial C pool & flux after large disturbance: plant C pool decreases, Soil C pool increases or decreases

C-Flux, Early: NPP recovers quickly because of increase in resource availability; decomp. rapid because of increase in labile C, temperature and water availability
NEP negative because of high C loss, decomp., and low NPP

Front 21

Nutrient Cycling in Primary Succession

Back 21

post-disturbance: high nutrient loss, then accumulation due to large biomass increment & N fixation
mid-succession: essential/limiting nutrients retained most strongly in biomass, little loss
late-succession: system stabilizes; nutrient outputs = inputs; NEP = 0

Front 22

nutrient cycling in secondary succession

Back 22

pulse of nutrient availability after disturbance
(fires increase N availability, susceptible to loss)

Fate depends on retention mechanisms:
-plant uptake
-microbial uptake
-chemical fixation

Front 23

Temporal dynamics in ecosystems

Back 23

(other than succession)
temporal extrapolation requires understanding of timescale of variables affecting processes
-diurnal
-seasonal
-annual
-inter-annual
-multi decadal

Front 24

fluxnet Canada

Back 24

research on climate, disturbance & C cycling in canadian forests/parklands
-N carbon sink absorbs 15-30% of global C

Front 25

diurnal cycles

Back 25

NEP negative at night, positive during day
weak cycle = disturbed sites, mature conifer stands & peatlands
strongest cycle = intermediate ages & deciduous forests

disturbed sites = net source
intermediate/deciduous forests = net sinks

Front 26

seasonal fluctuations

Back 26

-plants senesce in autumn (in response to photoperiod)
-grow rapidly in spring
-when GEE begins early = net sink
Net Ecosystem Exchange (NEE) = PS rate (GEE) + respiration rate (R)

GEE begins in spring, increasing as nighttime temps warms (through Oct)

NEE ceases midsummer due to increasing respiration

Front 27

inter-annual fluctuations

Back 27

Pacific Decadal Oscillation (PDO)
-N. Pacific
-phases of 20 - 30 yrs
-positive phase since 1977

Atlantic Multi-decadal Oscillation (AMO)

Front 28

Disturbance

Back 28

any relatively discrete event in space and time that disrupts ecosystem, community, or population structure & changes resources, substrate or the physical environment

Front 29

disturbance properties

Back 29

Magnitude: size or spatial extent of event

Intensity: force of the event

Severity: defined in terms of it's killing effect; measures the impact of the event on system properties

Front 30

exogenous disturbance

Back 30

those originating from outside the system

Front 31

endogenous disturbance

Back 31

those originating from within the system

Front 32

indirect disturbance

Back 32

doesn't kill individuals
alters resource levels or other factors influencing individuals

Front 33

direct disturbance

Back 33

killing disturbance
death of individuals, opens space & releases resource to others

Front 34

biotic disturbance

Back 34

disturbance agent is a living organism

Front 35

abiotic disturbance

Back 35

disturbance agent is not a living organism

Front 36

Insects: anthropogenic contributions to susceptible trees

Back 36

-effective fire suppression (<1% of historic area currently burns)
-selective harvesting (<1970 lodgepole a 'weed')
-overabundance of mature pine (>3X susceptible hosts)

Front 37

tree biology w.r.t. pine beetle

Back 37

beetles prefer large trees:
- high quality food & larval habitat
-protection from natural enemies & weather extremes

large trees tend to be more resistant
-con-situate resin ducts
-induced resin production

Front 38

pine beetle
biology basics

Back 38

colonizing beetles emit aggregation pheromones
-resultant mass attack overwhelms tree defences

beetles also introduce blue-stained fungi
-pathogenic to most trees
-block vascular tissue, stop resin production
-provides nutrients for maturing beetles

Front 39

pine beetle
current outbreak + predictions

Back 39

area affected = 18 million ha

projection:
mortality of 60% of mature pine by 2020

Front 40

endemic populations

Back 40

-insufficient beetles to colonize healthy trees
-normally found in trees attacked by others
-attacked trees rare and scattered
-mortality and off spring in balance
(97.5% mortality)

Front 41

beetle mortality factors

Back 41

host resistance
woodpeckers
competition
weather
pathogens
invertebrates
-relaxation of one or more of these factors allows population to build and move from endemic to incipient to epidemic populations

Front 42

incipient populations

Back 42

-infestations scattered
-number of trees infested increases annually
-clumps of infested trees grow in size and number over time
-most attacked trees in larger diameter classes
(95.0% mortality)

Front 43

epidemic populations

Back 43

-widespread
-large annual increase in infested areas
-extremely resistant to losses through normal mortality
(80 - 95% mortality)

Front 44

causes of outbreak

Back 44

abundant susceptible hosts

climate favouring beetle survival

Front 45

model of climatic suitability (beetles)

Back 45

P1: sufficient heat accumulation for synchronized one year life cycle

P2: minimum winter temperatue >-40C

P3: average maximum August temp >= 18C

P4: total ppt from April to June below long term average

Front 46

outbreak consequences

Back 46

forest C dynamics:
decrease C uptake (trees dead)
increase in C emissions from decaying

Front 47

fire suppression paradox

Back 47

Stand initiating fires + fire exclusion
leads to: fuel buildup
leads to: unusually severe fires
leads to: human costs and economic losses

mitigation: thinning, prescribed burns

Front 48

human impacts on fire regimes

Back 48

due to historical data we expect evidence of a fire every 20 years

1945 - 2005 there no evidence or fires

Front 49

Fire: Lessons Learned

Back 49

historical fires in mountains
-low to high frequency and severity

human and climate influences on fire:
-fire free period = mostly fire suppression
-global climate influences drought & fire
-current forests and fuels
-natural processes & fire suppression effects

Front 50

wind

Back 50

-major disturbance in coastal BC
-windthrow plows soil, creates microsites
-creates uniform, multi-cohort or all aged stands
-maintains structurally diverse lanscapes
-should be recognized in planning

Front 51

turning moment
+ factors

Back 51

function of lever arm length and gravity

-wind speed
-crown size/density/mass
-stem mass/elasticity
-tree height
-tip displacement

Front 52

tree resistance to wind

Back 52

by having a thick stem and good root system
-taller tree = longer lever arm, therefore need to counteract turning moment accordingly by increasing stem and root system

also: stream lines in the wind with branches deflecting to be aerodynamic and more porous

Front 53

Armstrong Technique

Back 53

test tree resistance to wind by pulling down with winch + cable

critical turning moment = max resistance of tree before it falls

Front 54

"slenderness ratio"

Back 54

height/diameter ratio
-low (<60) = stocky
-high (80-100) = tall/skinny

Front 55

worst soil for tree stability

Back 55

fertile but shallow
-lots of biomass accumulation above ground
-unable to get a good deep root system

Front 56

wind + hills

Back 56

wind acceleration (top speed) @ crest
turbulence on leeward side

most windthrow happening at crest

Front 57

Stand Level Effects of Wind

Back 57

wind disturbance can perpetuate themselves by creating stands that are high competition therefore tall & skinny and susceptible to further wind throw

-profound effects on soil: turning, can reverse paludification, adds woody debris to stream beds and helps structure them

Front 58

Landscape Level Effects of Wind

Back 58

smaller lower on the slope; wind throw @ crests
landslides mid-steep slope, paludification on lower slopes
hypermaritime: most productive areas mid slope

Front 59

The disease triangle

Back 59

need three things:
susceptible tree host (native vs. introduced)
virulent pathogen (native vs. introduced)
conducive environment (environment/climate change; man made perturbances)

Front 60

Pathogens as Good Guys

Back 60

-create stand openings
-increases diversity
-increases resilience
-wild-life habitat
-nutrient cycling

Front 61

symptom

sign

Back 61

effect of the disease on the host, host reaction

the pathogen itself

Front 62

Disease Epidemic Causes

Back 62

forest (mis)management
invasive alien pathogens
-see disease triangle

Front 63

Fungi Roles

Back 63

Saprophytes
-decomposition of cellulose and lignin
-C and nutrient cycling
Symbionts
-mycorrhizal associations with plant roots
-water, nutrient exchanges, protection
Pathogen
Food for wildlife

Front 64

Categories of Forest Pathogens

Back 64

Foliar
Stem
-cankers
Root
-root rots, wilt
Mistletoes
Rusts
Decay Fungi
-brown/white rot

Front 65

Disease Prevention

Back 65

diagnosis:
-learn to recognize pathogens, conduct proper diagnosis
Epidemiology
-understand pathogen biology, survival, dissemination
Disease Management
-know toolbox of options

Front 66

Deer & Haida Gwaii

Back 66

sitka black tailed deer
-introduced in 1876 by Revd Collison as a source of meat
-mild climate, abundant food,no competition, no predators
-exponential population growth with minor dips due to food shortage, weather, disease
-helped by clearcut logging, abundance of forage

Front 67

cost & benefits of introduced species

Back 67

biological impacts of most negative (cause a decrease in diversity)
on haida gwaii: decrease in W. red cedar, shrurbs & wildflowers; increase in hemlock & spruce.

economic & cultural value may be positive
-clearings, grassy meadows preferred over impenetrable shrubs; hunting

Front 68

Ecological Impacts - Introduced Species

Back 68

Effects on Insects
-vegetation and litter fauna
Understory fauna
-deer decreases resource quantity and quality
Negative Feedback
-lack of pollinators decreases plants further
Litter Fauna
-deer decrease resource quality: decreasing deciduous litter, increasing conifer litter, decrease protection from elements
-increase millipedes, decrease snails/slugs - has an effect on decomposition rate/completeness

Front 69

water cycle

Back 69

driven by solar radiation that generates evaporation & atmospheric circulation

Precipitation
-canopy interception
-infiltration/runoff
-percolation
-water tables
Evaporation
Transpiration
-streamflow

Front 70

Orographic PPT

Back 70

result of topography
geography and prevailing wind direction matter
important in BC

Front 71

Frontal/Cyclonic PPT

Back 71

large weather systems
created by convergence of air masses
longer, affects relatively large regions

Front 72

Convectional Rainfall

Back 72

summer thunderstorms
short/localized

Front 73

Evaporation Factors

Back 73

driven by solar radiation E
water vapour pressure
vapour pressure deficit (VPD)

Front 74

Solar Radiation Energy

Back 74

provides energy required to convert water from liquid to gas phase
creates wind which can cause convective evaporation
heats air mass and increases water holding capacity of air

Front 75

Water Vapour Pressure

Back 75

measure of amount of water vapour in air
function of air temp and available water
saturation vapour pressure = @ equilibrium with the liquid phase
actual vapour pressure = a value btwn 0 and saturated vapour pressure

Front 76

Vapour Pressure Deficit (VPD)

Back 76

measure of drying potential of air
difference btwn actual vapour pressure & saturated vapour pressure at a given temperature
inversely related to relative humidity (%)
(as RH increases VPD decreases)

Front 77

Canopy Interception

Back 77

Depends on
-leaf are index
-rainfall intensity

Front 78

Surface Evaporation

Back 78

Depends on
-quantity of solar radiation reaching forest floor
-water holding capacity of surface litter (LFH layers)

Front 79

Soil Evaporation

Back 79

sames as surface area evaporation plus:
-mineral soil particle size
(clay>silt>sand)

Front 80

Plant-Air-Soil continuum

Back 80

because of pressure gradient trees act like a wick drawing water from soil into atmosphere
-leaves act as pump, water into roots and up the stem
-water moves up through xylem with hydrogen bonding cohesion
-soil water moves toward roots along pressure gradient

Front 81

Community
(plant community ecology)

Back 81

an assemblage of species that live in an environment and interact with one another, forming a distinctive living system with it's own composition, structure, environmental relations, development and function

Front 82

Trait

Back 82

distinct variant of phenotypic characteristic of an organism
-may be inherited, environmentally determined or a combo of the 2

rooting depth = characteristic
shallow/deep roots = trait

Front 83

Diversity

Back 83

degree of variation of life within an ecosystem, biome or planet
-richness, evenness

Front 84

Species Interactions

Back 84

mutualism (+, +)
predation/parasitism (+, -)
competition (-, -)
commensalism (0, +)
amensalism (0, -)
neutralism (0, 0)

Front 85

Competition

Back 85

(-, -)
individuals using same resources will compete if that resource is in short supply
-results in niche partitioning

Front 86

Mutualism

Back 86

(+, +)
both interacting partners benefit from the relationship
-symbiosis
-believed to be the most common interaction in nature by some ecologists

Front 87

Amensalism

Back 87

(0, -)
a relationship where a product of one organism has a negative effect on another
-ie/ alleopathy

Front 88

Symbiosis

Back 88

different organisms living together
-usually in close association with one another to the benefit of one or more of them

mutualism (+, +)
Parasitism (+, -)
Commensalism (+, 0)
Amensalism (-, 0)

Front 89

Impact of Organisms Depends On:

Back 89

number; richness (each species unique, some species ecologically similar)
abundance; evenness (rare species, dominant species)
ID; composition (compensating species, keystone species)

Front 90

Functional Groups

Back 90

groups of species that are similar in traits and in effects on ecosystem processes
(ie/ N-fixing bacteria, deciduous trees)

-helpful in predicting effect of species losses on ecosystems, draw generalities

Front 91

Functional Groups Caveat

Back 91

no two species within group are exactly alike
-species competing for same resource cannot stably co-exist: one will take over, leading to extinction or shift towards different ecological niche of the other

Front 92

Foundational Species

Back 92

dominant species whose:
"architecture and functional ecology define forest structure and whose species specific traits control ecosystem dynamics"

-any tree when it is functionally unique
-change in these species more likely to have ecosystem effects than change in rare species

Front 93

Keystone Species

Back 93

Species that are more important to ecosystem processes than their abundance might suggest
-affect many other organisms in an ecosystem
-help to determine types & numbers of various other species in a community

Front 94

Effects of Species Diversity

Back 94

-enhance efficiency of resource use
-stabilize ecosystem processes in a variable environment
-insurance against radical ecosystem changes

Front 95

Temporal Ecosystem Dynamics & Resilience

Back 95

NOT STATIC
ecosystems are constantly changing and disturbed
-they are never in equilibrium with the current environment
-temporal patterns that occur differ with scale & severity of disturbance observed
-response of ecosystem to perturbation depends on 6 properties

Front 96

Ecosystem Response to Disturbance Depend on:
(6)

Back 96

resistance
response
recovery
stability
resilience
robustness

Front 97

Resistance

Back 97

tendency not to change
-ability to absorb disturbance
-maintain certain structures & functions

Front 98

Response

Back 98

direction and magnitude of change

Front 99

Recovery

Back 99

extent of return to original state

Front 100

Stability

Back 100

rate of return to original state

Front 101

Resilience

Back 101

elasticity or ability to return to original state
-measure of amount of disturbance system can absorb without leaving stability domain

Front 102

Robustness

Back 102

amount of perturbation a system can tolerate without changing state

Front 103

Balls & Peaks

Back 103

pushing ball into new domain depends more on the way that it is pushed (even subtle) than how hard
-rapid threshold changes or exceeding "tipping points" can occur without warning
-low reversibility: in reality species loss begets more species loss

Front 104

Cup and Ball

Back 104

width of cup = range of natural variation (RONV)
management goal is to make sure we don't push the ball out of current stability domain

Front 105

how does decreasing biodiversity destabilize ecosystems?

Back 105

1) declining species richness lowers ecosystem function
2) at least one functional group, preferably with redundancy, essential to ecosystem stability
3)the nature of response to species loss depends on which species is lost
-degrading system (or pushing out of RONV = loss of stability

Front 106

Ecosystem

Back 106

a functional system that includes an assemblage of interacting organisms and their environment; which acts on them and on which they act

Front 107

Ecosystem Ecology

Back 107

integrated study of biotic & abiotic components of ecosystems and their interactions with ecosystem framework

Front 108

ecosystem classification

Back 108

tool for understand & predicting responses of ecosystems occupying a given site

Front 109

Attributes of Ecosystems

Back 109

structure (components)
function (processes)
connectedness
complexity
intangible geographic boundaries
change over time

Front 110

structure (components)

Back 110

-plants, animals, microorganisms
-substrate (soil), atmosphere, water
-producers, consumers, decomposers
-food web

Front 111

function (processes)

Back 111

-constant exchange of matter and energy components
-Energy flow
-nutrient cycling
-water flux

Front 112

connectedness

Back 112

components interact and are interdependent

Front 113

complexity

Back 113

-high level of integration
-multiple feedbacks: positive (enforcing) & negative (dampening)
-all events and conditions have multiple determinants

Front 114

Intangible Geographic Boundaries

Back 114

-arbitrary
-connected to other ecosystems

Front 115

Ecosystem Change Over Time

Back 115

-not static in composition, structure or function
-altered from within (plant species effect)
-altered from without (fire, climate change)
-change within bounds determined by climate, site

Front 116

Natural Disturbances

Back 116

exogenous and endogenous
are an integral part of ecosystems, and more often than not are agents of renewal rather than destruction
-within historic range of variability
-some human disturbances are in this range

Front 117

Foreign Disturbances

Back 117

of a type or severity to which native species are maladapted, can be serious threat to ecosystem integrity
-may force system past a threshold into new regime
-degraded conditions
-become increasingly prevalent
- includes: uncommonly severe fires, climate change, & invasive species

Front 118

Maintain Ecosystem Integrity

Back 118

-maintain key ecological processes that reflect their natural condition
-manage population of species to levels with high likelihood of maintaining themselves
-maintain diversity of genes, species & communities native to region

Front 119

Prevent or Minimize Ecosystem Change

Back 119

Keep disturbances within historic range
-w.r.t. type and severity
-use forest practices that emulate natural disturbances
Prevent soil degradation
Maintain hydrology (water flux)
Foster resilience of ecosystems

Front 120

Managing for Resilience

Back 120

PROCESS STRATEGIES
-ecosystem level
-maintain desirable species an control undesirable species

PATTERN STRATEGIES
-landscape level
-maintain heterogeneous landscape with large and structurally complex patches of native vegetation connected by corridors

Front 121

Process Strategies

Back 121

1) maintain key species interactions and functional diversity
2)apply appropriate disturbance regimes
3) control aggressive, over abundant and invasive species
4) minimize ecosystem specific threats (pollutants, hunting)
5)maintain species of particular concern (keystone, rare)

Front 122

Pattern Strategies

Back 122

1) maintain and create large, structurally complex patches of native vegetation
2) maintain structural complexity throughout landscape
3) create buffers around sensitive areas
4) maintain/create corridors and stepping stones
5) maintain landscape heterogeneity and capture environmental gradients

Front 123

Managing for Complexity

Back 123

to foster resilience
-promote landscape connectivity
-retain or restore areas that may be buffered against climate change
-plant mixes of trees to reset successional patterns
-facilitate species (and population) migration and range shifts
-develop harvest, regeneration, & stand tending that maintains or enhances complexity

Front 124

Ecological Restoration

Back 124

-returning ecosystem to desired state
-usually a reference ecosystem or historical reference
-restoration attempts to return an ecosystem to its historic trajectory

Front 125

Restoration Ecology

Back 125

the science on which the practice of ecological restoration is based

Front 126

Attributes of a Restored Ecosystem

Back 126

1) characteristic assemblage of species
2) indigenous species
3) all functional groups required
4) physical environment capable of sustaining reproducing populations
5) functions normally
6) integrated into larger ecological matrix
7) potential threats lowered
8) resistant
9) self sustaining

Front 127

Dilemmas in Ecosystem Restoration

Back 127

1) where to set ecological reference
2) historical reference often not achievable
3) exotic species often unavoidable
4) exotic species contribute to ecosystem function
5) novel ecosystem the way of the future?
6) does it imperil conservation?

Front 128

Rehabilitation

Back 128

reparation of ecosystem processes, productivity and services

Front 129

Reclamation

Back 129

objectives include stabilizing the terrain, assuring public safety, improving aesthetics and returning land to a useful purpose

Front 130

Revegetation

Back 130

normally a component of land reclamation, often entails the establishment of only one or a few species

Front 131

Mitigation

Back 131

compensates environmental damage

Front 132

Creation

Back 132

installing a different type of ecosystem from that which historically occur

Front 133

Ecological Engineering

Back 133

manipulation of natural materials, living organisms and physical-chemical environment to achieve specific human goals and solve technical problems

Front 134

Landscape Ecology

Back 134

incorporates the dimension of space into ecological studies
-heterogeneity in ecosystems across space influence ecological processes
-ecosystem services vary across space

Front 135

Landscape Ecology & Management

Back 135

1) maintain and create large structurally complex patches of native vegetation
2)maintain structural complexity throughout the landscape
3) create buffers around sensitive areas
4) maintain/create corridors and stepping stones
5) maintain heterogeneity & capture environmental genetics

Front 136

Patch

Back 136

-nonlinear surface areas that differ in vegetation and landscape from their surroundings

Front 137

Matrix

Back 137

-dominant component of the landscape
-most extensive and connected landscape type
-dominant role in landcape ecology

Front 138

Corridor

Back 138

Linear, connect patches

Front 139

Categories of Ecosystem Services

Back 139

Provisioning Services
-food production, water, wood and fiber, fuel
Cultural Services
- spiritual, aesthetic, educational, recreational
Supporting Services
-nutrient cycling, soil formation, primary production, habitat provision
Regulating Services
-climate regulation, flood regulation, water purification

Front 140

Location Matters!
(Landscape Ecology)

Back 140

-incorporates the dimension of space into ecological studies
-heterogeneity in ecosystems across space influence ecological processes
-ecosystem services vary across space