Lacawac Hiking Trails
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  • Maurice Broun Trail
    • Fields & Meadows
    • Stone Walls
    • Gypsy Moth Caterpillars
    • Oak Trees >
      • White Oak
      • Red Oak
      • Black Oak
    • Raccoons
    • Owls
    • Snakes >
      • Snake ID
    • Bats >
      • Bat Houses
  • Lake Lacawac Trail
    • White Pine
    • Eastern Hemlock
    • Bog Plants >
      • Sphagnum Moss
      • Blueberry Bushes
      • Pickerelweed
    • Lake Lacawac
    • Glacial Bog
    • Diversity of Birds
    • Glacial Erratic Rock
    • American Black Bear >
      • Diet
      • Population
      • Reproduction
  • Big Lake Trail
    • Food Web
    • North American Beaver
    • Osprey
    • Watershed
    • Japanese Barberry >
      • Characteristics
      • Threat to Forest
      • Control Methods
    • Minerals & Rocks >
      • Minerals
      • Igneous Rocks
      • Sedimentary Rocks
      • Metamorphic Rocks
      • Identification
    • Sugar Maple
    • Streams
    • Hydroelectric Dam
    • Lake Wallenpaupack >
      • Electricity Generation
      • Recreation
      • Watershed Management
    • Wild Grapevines
    • Hayscented Fern
  • Carriage-Lakefront Trails
    • Phytoplankton
    • Harmful Algal Blooms
    • Riparian Zones
    • Bioindicators
    • Lake Macroinvertebrates
    • Lake Succession >
      • Oligotrophic Lake
      • Mesotrophic Lake
      • Eutrophic Lake
    • Lake Formation
    • Amphibians
    • Native Fish
    • Lake Research
    • Aquatic Plants
    • Zooplankton
    • Stratification
    • Lake Hydrology
    • Lake Chemistry
    • Monitoring for Preservation
    • Local Research with Global Implications
  • Historic Great Camp Trail
    • Connell Park
    • Sustainable Forestry
    • Hemlock Woolly Adelgid
    • Early Years
    • Field Station
  • Ledges Trail
    • Deer Exclosures
    • Geological Faults >
      • Normal Fault
      • Reverse Fault
      • Strike-slip Fault
    • Wild Orchids
    • Ledges
    • Ferns
    • Mosses & Lichen
    • Vernal Pools
    • Mushrooms
  • Watres Trail
    • Edge Effect
    • Hummocks and Hollows
  • Visitors Center
    • Native Plant Garden >
      • Golden Alexander
      • Black-Eyed Susan
      • Striped Cream Violet
      • Scarlet Beebalm
      • Blazing Star
      • Blue Moon
      • Blue Flag Iris
      • Tickseed
      • Coneflower
      • Butterfly Weed
      • Jerusalem Artichoke
      • Monkshood
      • Joe-Pye Weed
      • Mayapple
      • Blue Wood Sedge
      • Little Blue Stem
    • Bees
    • Weather Station
  • Partner Ridge Trail
  • Warbler Trail

Food Web

A food web consists of multiple food chains in an ecosystem. That is, each living organism is a part of a food web, and each food chain is a possible path towards energy and nutrients for that specific organism.


Picture

Trophic Levels

Organisms in food webs are grouped into categories called trophic levels. Roughly speaking, these levels are outlined by what an organism eats.

First level -- Producers also known as autotrophs make their own food and do not depend on any other organism for nutrition. Most use a process called photosynthesis to create glucose using energy from the sunlight, carbon dioxide, and water. Algae, plants, and phytoplankton (tiny organisms that live in water) are autotrophic.

Second level -- Primary consumers are herbivores. Herbivores like deer and mice eat plants, algae, and other producers.

Third level -- Secondary consumers eat herbivores. A snake that eats a mouse is a good example of a secondary consumer.

Fourth level -- Tertiary consumers eat the secondary consumers. An example of this would be an owl preying on the snake.
Decomposers make up the last part of the food chain. Detritivores are organisms that eat nonliving plant and animal remains. For example, scavengers such as vultures eat dead animals. Dung beetles eat animal feces.

Decomposers, like fungi and bacteria, complete the food chain. Decomposers turn organic wastes, such as decaying plants, into inorganic materials, such as nutrient-rich soil. They complete the cycle of life, returning nutrients to the soil or oceans for use by autotrophs. This starts a whole new series of food chains.
Picture

Biomass

Food webs are defined by their biomass. Biomass is the energy in living organisms. Autotrophs, the producers in a food web, convert the suns energy into biomass. However, biomass shrinks with each trophic level. That is because between 80% and 90% of an organism's energy, or biomass, is lost as heat or waste. This means that a carnivore like the wolf only consumes the remaining 10-20% of biomass.
Picture

Bioaccumulation

Biomass declines as you move up through the trophic levels. However, some types of materials, especially toxic chemicals, increase with each trophic level in the food web. These chemicals usually collect in the fat of animals. 

When a herbivore eats a plant or other autotroph that is covered in pesticides, for example, those pesticides are stored in the animal’s fat. When a carnivore eats several of these herbivores, it takes in the pesticide chemicals stored in its prey. This process is called bioaccumulation.
Picture
Trophic Levels
Biomass
Bioaccumulation

Location

About lacawac sanctuary

Lacawac Sanctuary Field Station and Environmental Education Center is an independent, non-profit, environmental education organization located on the shore of Lake Wallenp​aupack in the Northern Poconos.  We operate solely on program fees, memberships, sponsorships, grants and private donations from people like you

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  • Home
  • About
    • Sources
    • Contact Us
  • Maurice Broun Trail
    • Fields & Meadows
    • Stone Walls
    • Gypsy Moth Caterpillars
    • Oak Trees >
      • White Oak
      • Red Oak
      • Black Oak
    • Raccoons
    • Owls
    • Snakes >
      • Snake ID
    • Bats >
      • Bat Houses
  • Lake Lacawac Trail
    • White Pine
    • Eastern Hemlock
    • Bog Plants >
      • Sphagnum Moss
      • Blueberry Bushes
      • Pickerelweed
    • Lake Lacawac
    • Glacial Bog
    • Diversity of Birds
    • Glacial Erratic Rock
    • American Black Bear >
      • Diet
      • Population
      • Reproduction
  • Big Lake Trail
    • Food Web
    • North American Beaver
    • Osprey
    • Watershed
    • Japanese Barberry >
      • Characteristics
      • Threat to Forest
      • Control Methods
    • Minerals & Rocks >
      • Minerals
      • Igneous Rocks
      • Sedimentary Rocks
      • Metamorphic Rocks
      • Identification
    • Sugar Maple
    • Streams
    • Hydroelectric Dam
    • Lake Wallenpaupack >
      • Electricity Generation
      • Recreation
      • Watershed Management
    • Wild Grapevines
    • Hayscented Fern
  • Carriage-Lakefront Trails
    • Phytoplankton
    • Harmful Algal Blooms
    • Riparian Zones
    • Bioindicators
    • Lake Macroinvertebrates
    • Lake Succession >
      • Oligotrophic Lake
      • Mesotrophic Lake
      • Eutrophic Lake
    • Lake Formation
    • Amphibians
    • Native Fish
    • Lake Research
    • Aquatic Plants
    • Zooplankton
    • Stratification
    • Lake Hydrology
    • Lake Chemistry
    • Monitoring for Preservation
    • Local Research with Global Implications
  • Historic Great Camp Trail
    • Connell Park
    • Sustainable Forestry
    • Hemlock Woolly Adelgid
    • Early Years
    • Field Station
  • Ledges Trail
    • Deer Exclosures
    • Geological Faults >
      • Normal Fault
      • Reverse Fault
      • Strike-slip Fault
    • Wild Orchids
    • Ledges
    • Ferns
    • Mosses & Lichen
    • Vernal Pools
    • Mushrooms
  • Watres Trail
    • Edge Effect
    • Hummocks and Hollows
  • Visitors Center
    • Native Plant Garden >
      • Golden Alexander
      • Black-Eyed Susan
      • Striped Cream Violet
      • Scarlet Beebalm
      • Blazing Star
      • Blue Moon
      • Blue Flag Iris
      • Tickseed
      • Coneflower
      • Butterfly Weed
      • Jerusalem Artichoke
      • Monkshood
      • Joe-Pye Weed
      • Mayapple
      • Blue Wood Sedge
      • Little Blue Stem
    • Bees
    • Weather Station
  • Partner Ridge Trail
  • Warbler Trail