Transcript More on watersheds…then on to “riverscapes”

Habitat and biota
FISH 7380- Dr. e.r. irwin
Goals
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Review relations between biota and fluvial
habitats
Understand the what and why of HSC (and
other tools.
Look at a bigger picture: spatial and
temporal riverscape structure
It’s the habitat, silly.
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Stream biota as habitat specialists
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"...most fishes of small streams are habitat
specialists" (Gorman and Karr 1978)
- Evidence for habitat-specificity
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Habitat-use assessments (a lot!)
Relative to availability
Interspecific differences
Experimental manipulation (a few, e.g. Meffe and
Sheldon 1990)
Biotic versus abiotic
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Communities are the result of biotic forces
acting to to maintain communities at or
near equilibrium.
Communities are maintained by highly
variable and unpredictable abiotic forces
Stream fishes are habitat specialists
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Evidence for habitat-specificity
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Habitat use studies 70-80’s
Habitat use assessments
 Experimental manipulation (Meffee and Sheldon)
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Ongoing work…
Community structure related to habitat
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Species use a subset of available habitat
Similar species use different subsets
Moyle and
Vondracek 1985
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PCA
Low overlap among
adults and juveniles
Habitat gradients
SREL
SuckersKwak and
Skelly
(1992)
80
flathead catfish
Percent of total
70
habitat
60
50
40
30
20
10
0
Percent of total
Shallow-Fast
40
30
Slow-Cover
Deep-Fast
Shallow-Slow
ShallowCoarse
ShallowSlow
ShallowCoarse
channel catfish
habitat
20
10
0
ShallowFast
Slow-Cover Deep-Fast
How to use these data in
management…
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Premise: changes in habitat will lead to
predictable changes in fish assemblages.
HSC: habitat suitability curves
PHABSIM: habitat models
Progression to more complicated models
(2-d  3-d models) related to computer
power and GIS
HSC
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Modde and Hardy
(1992)
Problems with application:
mobile vs sedentary animals
e.g., Lazer and Madison (1995)
Spatial and temporal variability
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Fish are flexible
Use depends on availability and quality
Example-foraging minnows
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Again points to complexity of defining what
habitat is
Functional relations need to be defined in
terms of scale
Season/lifestage variation
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Patch concept
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Connection important
Ontogenetic shifts
Stream and species-variation
Riffle
Run
Pool
Percina sp. “Halloween darter” Adults
246
153
1
Percina sp. “Halloween darter”
Juveniles
80
94
12
Percina nigrofasciata Adults
12
13
13
P. nigrofacista juveniles
7
7
29
Well if we can’t K.I.S.S…
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Guild approach
Lobb and Orth
(1991)
Aadlund
(1993)
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Guilds in MN
streams
6 habitat guilds
Orth et al; still
working on this
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HSCs in new
M.S. thesis…
stay tuned
Critical habitat features
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"The key to understanding patterns of
community diversity among stream
fishes may be the definition,
understanding, and measurement of
relevant habitat characteristics under
the influence of of seasonally dynamic
physiochemical conditions". (Gorman
and Karr 1978)
Bain et al.; 5 habitat types
Habitat Type
N
Mean length sampled (m)
466
8.8
486
8.7
406
8.9
501
9.1
498
9.1
Criteria
Shallow-fast
Depth < 35 cm
Velocity  55 cm/s
Slow-cover
Velocity  20 cm/s
Cover present
Deep-fast
1
Depth  35 cm
Velocity > 45 cm/s
Shallow-slow
Depth < 35 cm
Velocity < 35 cm/s
Shallow-coarse
Depth < 35 cm
Substrata particle size  1 mm
Identify habitat characteristics most relevant
to biota,
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Strong temporal component
Habitat structure is a template for
population and community
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reproduction, energy flow, spp. interactions
Habitat effects on those processes may
vary through time and across systems:
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extreme levels
Source/Sink—Maintain function
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Organisms may specialize on particular
habitats because other habitats (in that
time-place) don't supply function (as well).
River management should be aimed at
maintaining function.
Critical habitat types
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Hydraulic units
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Rabeni and Jacobson
Bottlenecks and configuration
Other new approaches
“Natural Flow Regime” and management
of function
Temporal variation streamflow
Spawning Windows
100
Number of YOY/100 PAEs
90
80
70
P. palmaris
60
Percina sp.
50
C. callistia
40
C. venusta
30
20
10
0
0
50
100
150
200
250
Longest period without hydropeaking July-August (hours)
300
Availability of shallow habitats is high in a
hydropeaking reach of the Tallapoosa River…
PHABSIM data; Freeman, Bowen, Bovee and Irwin, 2001, Ecol. Appl. 11:179-190
80
80
60
60
40
40
20
0
1994
1995
20
Habitat availability, April-June,
0
based on hourly flows
1996 1997
1994 1995
Shallow-fast
Shallow-slow
1996
Deep-fast
1997
But hydropeaking greatly reduces temporal habitat
stability
Freeman, Bowen, Bovee and Irwin, 2001, Ecol. Appl. 11:179-190
80
80
60
60
40
40
20
0
1994
20
Maximum period of habitat stability, AprilJune, based on hourly
flows
0
1995 1996 1997
1994 1995 1996
Shallow-fast
Shallow-slow
Deep-fast
1997
Faunal response: e.g. Fish Abundance, IBI
a
b
d
c
Presen
t
Threshold
Base flow (during non-generation intervals)
Habitat template in stream
systems?
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Life history evolution
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Temporal variability
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Morphology (smaller body sizes in turbulent
habitats)
Harshness shapes communities
Structure also shapes communities
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RCC, lateral and landscape concepts
Hydrology: Characterizing
Streamflow
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Objectives:
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Acquire basic tools for characterizing
streamflow regimes
What hydrology means to a
stream ecologist:
Environmental variability through time.
 Poff and Ward 1990: "The long-term
regime of natural environmental
heterogeneity and disturbance may be
considered to constitute a physical habitat
template...that constrains the types of
species attributes appropriate for local
persistence."
Where hydrologic data come
from, and what they look like.
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http://water.usgs.gov
U.S. Geological Survey, Water Resources
Data your state, Water Year 19xx
years start in October
Five components of a flow regime, and
some tools for analyzing them
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Magnitude - annual means, seasonal
means, CV's
Example from AL:
Location
Little Tallapoosa at Newell
Tallapoosa near Heflin
Little River near Blue Pond
Period of
Record
1976-1994
1952-1994
1959-1967, 1971-1994
Annual Mean
(cfs)
Drainage Area
sq mi
Annual Runoff
(cfsm)
594
686
491
406
448
199
1.46
1.53
2.47
1984-1997 AAD = 72.5 m3/s
180
Average flow, m3/s
160
140
120
100
80
60
40
20
0
Day April 1-August 31 1952-1995
3
Flow, m /s
Hourly flow-R.L. Harris Dam
450
400
350
300
250
200
150
100
50
0
Hourly flow data: April 1 - August 31 1995
Frequency
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Proportion of years when a given event is
equaled or exceeded
frequency curves
Duration
Location
Little Tallapoosa at Newell
Tallapoosa near Heflin
Little River near Blue Pond
Annual 7 day
Minimum (cfs)
42
14
0.29
Exceedence Flows (cfs)
50%
10%
90%
361
420
166
100
120
5.5
1250
1280
1240
Duration
Two more things
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Timing
Rate of change
IHA
Finding hydrologic pattterns
among streams
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3 gradients:
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high to low flood
frequency
high to low flood
predictability
intermittent to
perennial flow
Ecological
characteristics of fish
assemblages (at least)
may correspond to
hydrology
Bayley and Li (1992)