Ecology Field Investigation

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Enquiry questions

How does an environmental factor affect the distribution and abundance of organisms in a habitat?

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Concepts

This study delivers 1 primary concept and 4 secondary concepts.

Primary concept: Ecosystems and Interdependence (BI-KS4-C017)

Type: Knowledge | Teaching weight: 3/6

An ecosystem is the interaction of a community of organisms with their abiotic (non-living) environment. Organisms within an ecosystem compete for limited resources and depend on each other through feeding relationships, pollination, seed dispersal and decomposition. Producers form the base of food chains; energy is transferred through trophic levels but with significant losses at each stage.

Teaching guidance: Required Practical 9: use quadrats and transects to sample the distribution and abundance of organisms. Pupils should be able to construct food chains and webs from data, calculate efficiency of energy transfer between trophic levels, and explain why food chains rarely have more than five trophic levels. Discuss keystone species and how the removal of one species can cascade through an ecosystem. Key vocabulary: ecosystem, community, population, abiotic, biotic, producer, consumer, decomposer, food chain, food web, trophic level, energy transfer, efficiency, keystone species, quadrat, transect Common misconceptions: Students think producers make 'food' from nothing — clarify that producers use light energy and inorganic molecules (CO2, water, minerals) to make organic molecules. Students also think energy is recycled through food chains — energy flows in one direction and is lost as heat; only matter is recycled.

Differentiation

Model response (Emerging): A producer makes its own food using photosynthesis, e.g., grass. A consumer cannot make its own food and must eat other organisms, e.g., a rabbit (primary consumer) eats grass.

Model response (Developing): Energy is lost at each trophic level. Rabbits use most of the energy from eating grass for their own life processes (movement, body heat, excretion), so only about 10% of the energy is passed on to the fox when it eats the rabbit. This means less energy is available to support foxes, so the population is smaller.

Model response (Secure): Mean number of daisies per quadrat = (5+3+7+4+6+2+5+4+6+3) / 10 = 45/10 = 4.5. Total area of field = 200 m². Area of one quadrat = 0.25 m². Estimated population = mean per quadrat × (total area / quadrat area) = 4.5 × (200 / 0.25) = 4.5 × 800 = 3,600 daisies.

Model response (Mastery): Net primary productivity (NPP) = Gross primary productivity (GPP) - respiration = 20,000 - 12,000 = 8,000 kJ/m²/year. This is the energy available to the primary consumers. Energy transfer efficiency = energy assimilated by primary consumers / NPP × 100 = 1,200 / 8,000 × 100 = 15%. Of the energy assimilated by primary consumers, 960 kJ is used for respiration, leaving only 240 kJ available for secondary consumers. The low efficiency (15%) explains why food chains are short: after 4-5 transfers, insufficient energy remains to support another trophic level.

Secondary concept: Transpiration and Plant Transport (BI-KS4-C007)

Type: Process | Teaching weight: 3/6

Water is absorbed by root hair cells and transported up the plant through xylem vessels by the process of transpiration. Dissolved sugars produced in photosynthesis are transported through phloem vessels by translocation. Transpiration rate is affected by light intensity, temperature, humidity, wind speed and the size and distribution of stomata.

Differentiation

Secondary concept: Photosynthesis (BI-KS4-C010)

Type: Process | Teaching weight: 3/6

Photosynthesis is an endothermic reaction in which light energy is absorbed by chlorophyll and used to convert carbon dioxide and water into glucose and oxygen. The glucose produced is used for respiration, converted to starch for storage, used to synthesise cellulose for cell walls, or used to make other biological molecules.

Differentiation

Secondary concept: Evolution by Natural Selection (BI-KS4-C016)

Type: Knowledge | Teaching weight: 3/6

Evolution by natural selection occurs when: there is variation within a population; some of that variation is heritable; individuals compete for limited resources; individuals with advantageous traits are more likely to survive and reproduce; advantageous alleles become more common in the population over generations. Speciation occurs when populations become reproductively isolated and evolve independently.

Differentiation

Secondary concept: Biodiversity and Human Impact (BI-KS4-C018)

Type: Knowledge | Teaching weight: 3/6

Biodiversity refers to the variety of life in an area, including the number of different species (species richness) and the genetic diversity within species. Human activities threaten biodiversity through habitat destruction, pollution, introduction of invasive species, overexploitation and climate change. Conservation programmes aim to maintain biodiversity and restore damaged ecosystems.

Differentiation

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Thinking lens: Systems and System Models (primary)

Key question: What are the parts of this system, how do they interact, and what happens when something changes? Why this lens fits: Food chains, food webs and ecosystems are system models: pupils map components (producers, consumers, decomposers), trace energy flows, and predict what happens when one part changes. Question stems for KS4:

What assumptions does this model make, and how do they limit its predictions?

Are there tipping points where small changes produce large systemic effects?

How would you choose between two competing models of this system?

Can this phenomenon be explained by looking at parts alone, or does it require a systems perspective?

Secondary lens: Patterns — Data from repeated investigations reveals patterns that allow pupils to generalise their findings beyond the specific test conditions.

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Session structure: Fieldwork

Fieldwork

Learning through direct observation and data collection in the field (or simulated field environment). Includes preparation and planning, systematic data collection using fieldwork techniques, data processing and presentation, analysis of findings, and a conclusion that addresses the enquiry question.

preparation → field_data_collection → processing → analysis → conclusion Assessment: Fieldwork report including methodology, data presentation using appropriate techniques (maps, graphs, tables, photographs), analysis of patterns, and conclusion with evaluation of data reliability. Teacher note: Use the FIELDWORK template: expect pupils to design a fieldwork methodology with justified sampling, appropriate quantitative and qualitative techniques, and risk assessment. Demand rigorous data processing including statistical analysis where appropriate. Guide critical evaluation of methodology, data quality, and conclusions, with reference to how fieldwork evidence supports or challenges geographical or scientific theory. KS4 question stems:

How does your sampling strategy ensure your data is representative?

What statistical techniques will you use to analyse your field data?

How do your fieldwork conclusions relate to the broader geographical or scientific theory?

What methodological improvements would strengthen your investigation?

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Variables

Independent: distance along transect (proxy for environmental gradient) or specific abiotic factor Dependent: abundance or percentage cover of target species Controlled: quadrat size, sampling method (systematic along transect), time of day, season

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Equipment and safety

Equipment:

quadrats (0.5m × 0.5m)

tape measures (30m)

identification keys

light meter

soil moisture meter

soil thermometer

pH meter or indicator paper

tally counters

clipboards

calculator

Safety notes: Complete a site-specific risk assessment before fieldwork. Check for pupil allergies (pollen, insect stings). Wear appropriate clothing and footwear. Wash hands thoroughly after handling soil and organisms. Stay within designated areas. Carry a first aid kit. Avoid unstable ground near water bodies. Check weather forecast and postpone in dangerous conditions. (Hazard level: low)

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Expected outcome

Organisms are not randomly distributed — their abundance correlates with abiotic factors (light, moisture, pH, temperature). A belt transect across an environmental gradient (e.g. field to woodland edge) reveals systematic changes in species distribution. Pupils can calculate species frequency, percentage cover, and population estimates using sampling data. Statistical analysis reveals whether observed patterns are significant or due to chance.

Recording format: belt transect data table (species count per quadrat at each distance), kite diagram or bar chart of species distribution along transect, scatter graph of species abundance vs abiotic factor, population estimate calculation

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Enquiry type

Observation Over Time

A systematic enquiry where changes are observed and recorded at intervals over a period of time — hours, days, weeks, or longer. Used when the process being studied is too slow for a single lesson or when the pattern only emerges through repeated observation. Develops patience, systematic recording, and the ability to identify trends.

Question stems:

How does [thing being observed] change over time?

What happens to [variable] over [time period]?

What pattern can you see in how [process] changes?

Teacher scaffold:

What do you think will happen over time? Why?

How often should we observe and record?

What exactly will we look for or measure each time?

What pattern can you see in the observations?

Can you explain why this pattern happens?

Pattern Seeking

An enquiry where pupils look for relationships or correlations between variables in situations where it is not possible or appropriate to control all the variables. Data is collected and analysed to determine whether there is a pattern — 'Is there a link between X and Y?' — without necessarily establishing causation.

Question stems:

Is there a pattern between [variable A] and [variable B]?

Do [things with property X] also tend to [show property Y]?

Can you put these in order of [property] and see what pattern emerges?

Teacher scaffold:

Is there a pattern between [variable A] and [variable B]?

What do you notice when you compare [these examples]?

Can you put these in order? What pattern emerges?

Why might this pattern exist?

Does the pattern always hold, or are there exceptions?

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Known misconceptions

Removing one species only affects its predator

What pupils may say: Removing one species from a food web only affects the animal that eats it. Correct explanation: Removing a species from a food web has cascading effects throughout the ecosystem due to interdependence. If a prey species is removed, its predators lose a food source (they may decline or switch prey). The organisms the prey species ate may increase in number. These changes ripple through the entire web. This is why biodiversity matters — the more connections in a food web, the more resilient it is. Diagnostic questions:

If all the rabbits in a meadow ecosystem died, which other organisms would be affected? Only foxes?

What would happen to the grass if the rabbits disappeared?

Why does removing one species affect organisms that are not directly connected to it?

Decomposers are unimportant

What pupils may say: Decomposers are not important in an ecosystem — they just eat dead things. Correct explanation: Decomposers (bacteria and fungi) are essential for recycling nutrients. When organisms die, decomposers break down the dead material and release minerals back into the soil. Plants absorb these minerals and use them to grow. Without decomposers, nutrients would be locked up in dead organisms and the soil would become depleted, eventually preventing plant growth and collapsing the entire food web. Diagnostic questions:

What would happen if all the decomposers in an ecosystem died?

How do nutrients get from dead organisms back to living plants?

Why are decomposers sometimes called 'nature's recyclers'?

Energy is recycled in ecosystems

What pupils may say: Energy is recycled in an ecosystem just like materials are. Correct explanation: Energy flows through an ecosystem in one direction and is not recycled. At each trophic level, energy is lost as heat through respiration. This is why food chains rarely have more than four or five levels — there is not enough energy left to support another level. Materials (nutrients like carbon and nitrogen) ARE recycled through biogeochemical cycles. Energy flows; materials cycle. Diagnostic questions:

What happens to the energy at each level of a food chain?

Why are there usually only 4-5 levels in a food chain?

What is the difference between how energy and materials move through an ecosystem?

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Why this study matters

Fieldwork is irreplaceable for developing scientific reasoning about real ecosystems. The belt transect method provides a structured approach to pattern seeking in a complex, variable environment. Correlating species distribution with measured abiotic factors teaches pupils to identify relationships in data without controlled experiments — a critical distinction from fair testing. The inherent messiness of ecological data develops statistical thinking and the ability to draw cautious conclusions.

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Pitfalls to avoid

Pupils place quadrats only in visually interesting areas rather than at systematic intervals along the transect — enforce systematic or stratified random sampling

Confusing correlation with causation — just because daisy abundance correlates with light intensity does not prove light causes the pattern; there may be confounding variables

Difficulty estimating percentage cover consistently — practise with photographs before going outside

Sensitive content

Fieldwork requires risk assessment — check allergies, ensure appropriate clothing, and carry first aid equipment

Some pupils may be anxious about outdoor environments or handling organisms — provide alternatives for engagement

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Vocabulary word mat

Prior knowledge (retrieval plan)

Pupils should already know the following from earlier units:

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Scaffolding and inclusion (Y10)

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Knowledge organiser

Key terms:

ecosystem

community

population

abiotic factor

biotic factor

quadrat

transect

systematic sampling

percentage cover

biodiversity

species richness

Core facts (expected standard):

Ecosystems and Interdependence: Calculates energy transfer efficiency between trophic levels, uses quadrats and transects to estimate population size, and explains the carbon and water cycles.

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Graph context

Node type: ScienceEnquiry | Study ID: SE-KS4-006 Concept IDs:

BI-KS4-C017: Ecosystems and Interdependence (primary)

BI-KS4-C007: Transpiration and Plant Transport

BI-KS4-C010: Photosynthesis

BI-KS4-C016: Evolution by Natural Selection

BI-KS4-C018: Biodiversity and Human Impact

Cypher query:

``cypher

MATCH (ts:ScienceEnquiry {enquiry_id: 'SE-KS4-006'})

-[:DELIVERS_VIA]->(c:Concept)

-[:HAS_DIFFICULTY_LEVEL]->(dl)

RETURN c.name, dl.label, dl.description

``

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Generated from the UK Curriculum Knowledge Graph — zero LLM generation.