Ecosystem Expedition Activity Sheet
Biology Field Journal
Ecosystem Expedition
Name:
Date:
Period:
Welcome to the field! Decode trophic levels, trace energy pathways through complex food webs, and investigate how species coexist.
1
Trophic Scramble & Mystery Cipher
5 Points
Unscramble each ecological role. Then copy the highlighted letters to crack the mystery species concept at the bottom!
A. C R P D O U E R
Makes food:
B. H B E V I R O R E
Plant-eater:
C. C M O P S E D E O R
Recycler:
D. C O N S M E R U
Eats others:
Mystery Term: Organism whose removal radically destabilizes the ecosystem:
2
Food Web Logic & Energy Flow
8 Points
Temperate Meadow Field Observation Network
Sunlight → [Wild Grass / Clover] → [Grasshopper & Field Mouse] → [Garter Snake] → [Red-Tailed Hawk]
Q1: Which organism above functions as the primary producer?
Q2: What does the direction of each arrow in a food web specifically show?
Q3: If a severe drought wilts 75% of the clover, predict the effect on the snake population:
Q4: Identify the organism operating at the highest trophic level (Apex Predator):
3
Ecological Niche Cross-Clues
4 Points
1. The physical place where an organism lives:
2. An organism's exact functional role/job in its habitat:
3. An animal eating both plant matter and animal prey:
4. Non-native species outcompeting local wildlife:
Ecosystem Expedition • Field Packet Page 1 of 4 Section Score: _____ / 17 pts
Part II: Terminology Grid
Ecosystem Sleuth & Factor Sorting
Student Name:
4
Ecosystem Term Sleuth (14x14 Grid)
14 Words • 14 Pts
P R O D U C E R X B I O M E A M U T U A L I S M Q W Z B C O N S U M E R K L P T N I A B I O T I C F R O G J I O R T R O P H I C H K S A C M N X D E C O M P O S E R H A I Y S Y M B I O S I S U E S V Z K E Y S T O N E X K T S O M N I V O R E Q R T F P A R H E R B I V O R E J Y L G E A U T O T R O P H W X K E P R E D A T O R Y V B K M T H A B I T A T Z G N E T W R B I O D I V E R S I T Y Q X
Word Bank Check when found
PRODUCER
CONSUMER
DECOMPOSER
HERBIVORE
CARNIVORE
OMNIVORE
TROPHIC
SYMBIOSIS
MUTUALISM
KEYSTONE
BIOME
ABIOTIC
HABITAT
BIODIVERSITY
Explorer Clue: Words run horizontally and vertically! Notice CARNIVORE down column 1, and BIOME resting across row 1.
5
Ecosystem Factors: Abiotic vs. Biotic
8 Points
Label each factor with A (Abiotic - non-living physical factor) or B (Biotic - living or once-living component).
1. Soil pH level
2. Mycorrhizal fungi
3. Dissolved oxygen
4. Rotting tree log
5. Solar irradiance
6. Nitrogen-fixing bacteria
7. Annual precipitation
8. Earthworm burrows
Ecosystem Expedition • Field Packet Page 2 of 4 Section Score: _____ / 22 pts
Part III: Ecological Interactions
Symbiosis Matrix & Energy Dynamics
Student Name:
6
Symbiosis Partnership Inspector
10 Points
Classify each relationship: M (Mutualism +/+), C (Commensalism +/0), P (Parasitism +/-), or COMP (Competition -/-).
1
Clownfish & Sea Anemone: The fish receives defense from stinging tentacles; its waste feeds the anemone and water movement provides aeration.
2
Barnacles on a Humpback Whale: Barnacles gain safe transit and access to plankton-rich currents; the whale experiences no measurable effect.
3
Deer Tick on a White-Tailed Deer: The tick feeds on the host's blood supply, transmitting dangerous pathogenic bacteria to the host.
4
Oak Tree & Spanish Moss: The epiphytic moss anchors onto high oak limbs to intercept sunlight and rainwater without penetrating tree tissue.
5
Hyenas & Vultures at a Carcass: Both scavengers aggressively contest access to limited edible leftovers on the savanna floor.
7
The 10% Energy Rule Calculations
8 Points
Energy decreases by approximately 90% at each step up the food pyramid. Calculate the available energy at each trophic level.
Apex Predator _____ Joules
Secondary Consumer _____ Joules
Primary Consumer (Herbivores) _____ Joules
Primary Producer: 100,000 Joules
1. Where does the missing 90% of energy go at each trophic tier?
2. Why are there rarely more than 4 or 5 trophic levels in any natural ecosystem?
Ecosystem Expedition • Field Packet Page 3 of 4 Section Score: _____ / 18 pts
Part IV: Dynamic Systems
Keystone Species & Ecological Succession
Student Name:
8
Case File: The Pacific Kelp Barrens
7 Points
Field Incident #402: In the Pacific Northwest, sea otters feed on purple sea urchins, which in turn chew through the holdfasts of giant kelp. When fur traders hunted sea otters to near extinction, sea urchin densities surged by 1,000%, devastating the towering kelp forests into barren rock flats.
Fill in the Cascade Effect (write: INCREASES or DECREASES):
Otter Population
→
Urchin Population
→
Kelp Forest Density
→
Biodiversity of Fish
Analysis: Explain why a keystone species is compared to the central wedge stone in an architectural arch:
9
Ecological Succession Timeline
8 Points
Number the succession stages from 1 (Earliest) to 4 (Climax Community) following a volcanic lava flow:
Shrubs, fast-growing pines, and small perennials
Bare basalt rock colonized by pioneer lichens
Stable, mature hardwood climax forest (Oak/Maple)
Thin soil layer forming, supporting mosses and grasses
Key Distinction: Does a forest fire lead to primary or secondary succession? Why?
Ecosystem Expedition • Field Packet Page 4 of 4
Grand Packet Total: _____ / 72 Points
