Lotic Ecosystems

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Lotic Ecosystems

• Rivers, brooks, creeks
• Controlled by current
• Little to no thermal stratification
• Oxygen distribution near uniform
• Adaptations to hold on
• Major energy source material carried in from
  outside

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• River Zones
• along length

rapids
Pools
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Lotic vs Lentic Life Modes
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Stream Trophic Modes
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River Continuum Concept

• Streams are gradients or continua
• Downstream processes linked to upstream events

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Small Headwater Streams
Cool, low light, few plants
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Medium headwater streams
More light, warmer, more plants
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Large Rivers
Warmer, low light penetration, phytoplankton
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Vernal Pools

• Definitions vary
• Names vary
• Prairie pothole
• Ephemeral wetlands
• Key features
• Seasonally flooded depressions
• no breeding fish pops

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Vernal Pools

• Specialized survival strategies
• Surrounding habitat important
• Species vary
• Age
• Climate
• Hydroperiod

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Vernal Pools

• Pros for Animals
• Access to high nutrition
• Lack of fish predators
• Con
• Dries out

Wood Frog
Fairy Shrimp
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Ecological Strategies

• Overwintering
• Burrow, cyst,egg
• Non-wintering migrants
• Leave when dry, return in spring
• Early Breeders, feeders
• Visitors

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Vernal Pools

• Wicked big puddles?
• Indicator species for ME
• Wood frog
• Spotted and blue-spotted salamanders
• Fairy shrimp

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