LongTerm Regional Ecology of Lake Districts

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Long-Term Regional Ecology of Lake Districts
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Major Questions

• How do relative locations of lakes matter?
• to lake characteristics?
• to long-term dynamics?
• What can we generalize to other lake districts?

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Long-Term Regional Ecology of North Temperate
Lakes

• Perceive long-term changes
• Understand within lake interactions
• Understand lake ecology at the lake-district
  scale
• Integrate atmospheric, hydrologic, and biotic
  processes regionally
• Understand interactions between lakes and society

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LANDSCAPE POSITION
A lakes explicit location relative to the type
and strength of its connection to a drainage
network.
(Magnuson and Kratz, in press)
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Landscape Position Influences Hydrology
Precipitation Input
Groundwater Input
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Trout Lake Hydrologic Flow System
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Landscape Position and Lake Attributes
Lowland
Highland
From Kratz et al. (1997)
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Lake Order
-3
-3
-1
-3
0
0
-2
-2
1
3
0
2
1
0
-1
-2
2
-3
2
-3
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Lake Area
1000
100
Hectares
10
1
34
-3
-2
-1
0
1
2
Lake Order
From Riera et al., in press
10
Specific Conductance
300
200
100
50
µS cm-1
10
5
-3
-2
-1
0
1
2
3
Lake Order
From Riera et al., in press
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Chlorophyll
40
20
10
µ g L-1
5
1
-3
0
2
-2
-1
1
34
Lake Order
From Riera et al., in press
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Fish Species Richness
30
20
Number of Species
10
0
From Riera et al., in press
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Cross-Site Comparison
Conductivity
Landscape Position
From Soranno et al., in press
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Lake Characteristics and Peoplerandom sample of
1150 property owners

• Identity (importance of lake to self) Behavior
  (likelihood of opposing environmental change)
• lake characteristics bear no relationship
• Attitude (satisfaction with lake)
• strong effect of lake characteristics
• preference for deep, clear lakes with little
  development or public access

From Stedman 1999
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(No Transcript)
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Coherence in 7 Northern Wisconsin LTER Lakes
1.0
0.5
Coherence (r)
0
-0.5
Biological
Chemical
Physical
From Kratz et al., 1998
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0.8
Comparisons
0.6
Major Ions
0.4
Coherence (r)
Nutrients
0.2
0.0
Southern Wisconsin LTER
Northern Wisconsin LTER
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Precipitation at Minocqua Dam, Wisconsin Deviation
from 30-yr mean (79 cm)
Drought
From Webster et al, in press
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Landscape Dynamics
Drought
Spatially Uniform
Geomorphology
Spatially Structured
Landscape Position
Spatially Random
Lake Specific
Lake Dynamics
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Standardized Calcium
3
2
1
Highland
0
Lowland
-1
-2
-3
80
82
84
86
88
90
92
94
96
From Webster et al, in press
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Standardized Calcium
ELA
Wisconsin
3
3
2
2
1
1
0
0
-1
-1
-2
-2
-3
-3
80
82
84
86
88
90
92
94
96
Highland
Lowland
From Webster et al, in press
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Cross-site Comparison
Geomorphology
Spatially Uniform
NOLSS and ELA
(Dorset Highland)
Landscape/Lake
Spatially Structured/ Random
Northern Wisconsin
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Landscape Position Influences Status and Coherence
Status
Coherence
High
Same
Low
Different
Landscape Position
Landscape Position
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Where to from here?
Improve our understanding of how landscape
position affects biological communities and
processes.
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Lake Categories
Connected
Isolated
Rare
Common
High
Landscape Position
Common
Rare
Low
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Effects of Landscape Position and Isolation on
Taxonomic Richness
Fish
Benthic Invertebrates
Isolated
Connected
Isolated
Isolated
Taxonomic Richness
Connected
Isolated
Connected
Connected
High
Low
Low
High
Landscape Position
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• Position in landscape matters
• Coherence patterns inform us about landscape
  level drivers
• Landscape-scale results have implications for
  Environmental Observatories

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Landscape Position and Coherence

1.0 0.8 0.6 0.4 0.2 0.0
Calcium Coherence (r2)
0.0 0.2 0.4 0.6 0.8 1.0
Groundwater
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0.8
Comparisons
All Pairs
Lowland vs. Lowland
Upland vs. Upland
Lowland vs. Upland
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Average Synchrony for 9 Chemical Variables
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Workshop on Ecological Organization of Lake
Districts Trout Lake Station February 5-7, 1997
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Research and MethodsStedman 1999

• How do attitudes and behaviors towards lakes vary
  according to lake characteristics physical
  (e.g., size), biochemical (e.g., chlorophyll),
  social (e.g., shoreline development)?
• Random sample (n1150) of Vilas Co property
  owners (72 response), each with particular lake
• Matched property owner data base with ERL, Birge
  Juday (thanks Joan!), Vilas County data
• Matched set had 262 different lakes (662
  respondents) represented by respondent data and
  at least one lake data set under-represents
  lakes under 50 acres.

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At what spatial scale
are biotic assemblages
most strongly structured?
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dissimilarity between sample sites
0.7
0.6
mean dissimilarity
0.5
within catchments
across catchments
within lake
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Workshop on Ecological Organization of Lake
Districts Trout Lake Station February 5-7, 1997

• 18 Participants Representing 13 Institutions
• 6 Countries
• Canada, Czech Republic, Ireland, Russia, UK, US
• Results in Special Issue of Freshwater Biology

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North Temperate Lakes LTER Trout Lake Area