Biology · Biodiversity, Global Change & Conservation

Biodiversity, livelihoods, environmental justice and decision evidence

A fictional conservation plan has total social benefit 28 units and burden 14, a positive net 14. Yet one group experiences benefit 8 and burden 12, net −4. The aggregate is accurate while hiding that group’s loss. Conservation decisions need evidence about biodiversity and people, together with a clear account of whose outcomes and values are included.

Begin with the biological levels, species identity and ordinary fractions introduced in the earlier biology lessons. Population Ecology & Life-History Patterns helps with demographic accounts, expected counts and conditional probabilities. Ecosystems, Energy Flow & Biogeochemical Cycles supplies the distinction between a process, a stock and an ecosystem boundary, while Species, Speciation & Macroevolution helps with the meaning and limits of species identities. The copy-pool probability examples can be read as complete sets of alternatives before learning binomial notation; return to the genetics lessons for inheritance, drift and relatedness.

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By the end, you can

Keep ecological outcomes, livelihood effects, equity and uncertainty explicit, and distinguish empirical predictions from the values and decision criteria used to choose among them.

Biodiversity supports livelihoods and matters in several ways

People depend on organisms and ecological processes for material contributions such as food and fibre, regulating contributions such as pollination and water-quality processes, and cultural relationships, knowledge and identity. These contributions are linked to human activities and institutions as well as biology. More production of one material does not automatically mean that every other ecological or social contribution increased.

Biodiversity also matters to people through relationships with particular places and organisms, and through judgments that living systems have value beyond their immediate usefulness. A price or a species count can provide relevant information without expressing every such value. Different kinds of evidence and value therefore need clear descriptions; a common unit is a justified modelling choice, not a fact that all real concerns are interchangeable.

Livelihood effects depend on who uses a place, who benefits elsewhere, access, timing and alternatives. A gain in a wider account can coincide with local restrictions or losses, and members of one named group can experience different effects. Indigenous and local knowledge can contribute ecological and historical evidence, while decisions about its use require respect for the knowledge holders and their own priorities. A group average does not represent every person’s circumstances.

An aggregate does not settle environmental justice

Environmental justice concerns how environmental benefits, burdens, decisions and recognition are organised. A useful conservation-equity framework distinguishes distribution, procedure and recognition. Distribution asks who receives gains, costs and risks. Procedure concerns meaningful influence, access to information and accountability in decisions. Recognition concerns respect for identities, knowledge, values and rights. These are connected questions, not alternative names for one net-benefit score.

The fictional ledger deliberately measures only distribution in assigned commensurable units. The restricted-access plan gives the local group net −4 and the wider group +18, total +14. The shared-governance plan gives +8 and +12, total +20. Those names and values are stipulated for comparison; they do not prove that a particular real governance arrangement always produces those outcomes.

The separate ecological scores 8 and 7 remain unlike the social units. Choosing a plan requires stating how ecological objectives, distribution and other constraints are treated. Even a plan with larger aggregate net gains may lack acceptable participation or recognition. Equally, a participatory process is not by itself proof that a biodiversity objective will be achieved. Both social and ecological claims need appropriate evidence.

A positive aggregate can conceal a burdened group

Distribution is one equity question. Respect for identities, rights and knowledge, and meaningful influence over decisions, cannot be inferred from this fictional net-benefit account.

Read the diagram in words

The restricted-access plan gives local net 8 − 12 = −4 and wider net 20 − 2 = 18, aggregate 14. The shared-governance plan gives 12 − 4 = 8 and 16 − 4 = 12, aggregate 20. Both assign total benefits 28, but burdens 14 versus 8. Separate ecological scores 8 and 7 cannot be added to these social units.

Benefit minus burden for this group
Fictional plan being compared	Group experiencing the assigned outcome	Assigned benefit units	Assigned burden units	Benefit minus burden for this group
Assigned restricted-access plan	Assigned local livelihood group	8	12	-4
Assigned restricted-access plan	Assigned wider beneficiary group	20	2	18
Assigned shared-governance plan	Assigned local livelihood group	12	4	8
Assigned shared-governance plan	Assigned wider beneficiary group	16	4	12

Aggregate across the two assigned groups
Fictional plan being compared	Assigned benefit units	Assigned burden units	Benefit minus burden for this group
Assigned restricted-access plan	28	14	14
Assigned shared-governance plan	28	8	20

Separate assigned ecological score
Fictional plan being compared	Separate assigned ecological score
Assigned restricted-access plan	8
Assigned shared-governance plan	7

Commensurable units only within this toy ledger

Assigned ecological-index units

An aggregate does not show how gains and losses are distributed

The ledger does not evaluate recognition, participation, rights or within-group differences

Original fictional one-horizon decision accounts. Benefit and burden units are stipulated commensurable and additive solely within this toy social ledger. Groups are aggregate categories, not equal numbers of people or internally homogeneous real communities. Ecological score is a separate assigned index, not species richness, money, utility or a measured conservation forecast. No actual livelihood, rights, consent, policy or preference ranking supplied.

Predicted outcomes and chosen criteria are different inputs

A decision comparison can state candidate actions, plausible conditions, costs, predicted outcomes and uncertainty. Evidence helps test those predictions and the conditions under which they might apply. Values help define what outcomes matter, what constraints must be respected and how trade-offs are judged. A numerical calculation can reveal a trade-off without choosing those goals on people’s behalf.

The two-scenario model assigns action X scores 9 in a wetter scenario and 2 in a drier one, while Y scores 6 in either. With equal scenario weights, the average scores are 5.5 and 6. Giving the wetter scenario weight 0.8 changes them to 7.6 and 6. The scores and weights are explicit assumptions, not measured climatic probabilities or claims about actual extinction risk.

A worst-supplied-case criterion instead compares X’s lowest score 2 with Y’s 6. That comparison does not use the scenario weights, and it is only as complete as the cases considered. Different rankings can reflect different beliefs about conditions or different decision criteria; those disagreements are not repaired by silently changing the numbers. Transparently stating uncertainty, objectives and whose evidence was included makes a decision open to reasoned evaluation.

The chosen decision rule can change the preferred plan

Uncertainty about outcomes and disagreement about values are different parts of a decision. Clear assumptions expose both; a calculated score does not settle either by itself.

Read the diagram in words

Action X scores 9 in W and 2 in D; Y scores 6 in both. Equal weights give X 5.5 and Y 6. Weights 0.8/0.2 give X 7.6 and Y 6. The lowest supplied scores are 2 for X and 6 for Y. Both costs 2 and 3 fit budget 3, but the ranking depends on the stated criterion and weights.

Assigned environmental scenario
Assigned environmental scenario	W / D
Assigned wetter scenario	W
Assigned drier scenario	D

Assigned score over the same horizon
Candidate action within the budget	Assigned wetter scenario	Assigned drier scenario	Assigned cost units	Lowest supplied scenario score
Candidate action X	9	2	2	2
Candidate action Y	6	6	3	6

Weight assigned to this scenario
Alternative weighting assumption	Assigned wetter scenario	Assigned drier scenario
Equal assigned scenario weights	0.5	0.5
Higher assigned weight on the wetter scenario	0.8	0.2

Score averaged with the stated weights
Alternative weighting assumption	Candidate action within the budget	Score averaged with the stated weights
Equal assigned scenario weights	Candidate action X	5.5
Equal assigned scenario weights	Candidate action Y	6
Higher assigned weight on the wetter scenario	Candidate action X	7.6
Higher assigned weight on the wetter scenario	Candidate action Y	6

Available assigned cost units
Available assigned cost units	=
Available assigned cost units	3

E = w × Y(W) + (1 − w) × Y(D)

Expected score and worst-case score are different criteria

A numerical ranking does not choose society’s goals or establish scenario likelihoods

Original two-scenario one-horizon decision exercise, exactly two candidate actions, assigned costs 2 or 3 units and budget 3. Scenario weights 0.5/0.8 are alternative stipulated belief cases, not fitted climate probabilities, frequencies of repeated future years or measured population risk. Scores are a selected common ecological index, not extinction probabilities or money. No complete social assessment or practical policy recommendation.

Worked example

Ask what the ranking includes and what it leaves open

For the restricted-access plan, local 8 − 12 = −4 and wider 20 − 2 = 18 sum to 14. For the alternative, local 12 − 4 = 8 and wider 16 − 4 = 12 sum to 20. Both total benefits are 28, but burdens differ 14 versus 8. Neither net specifies the number of people in a group, their starting income, consent, rights or within-group distribution.

For the independent scenario exercise, equal weights give X 0.5 × 9 + 0.5 × 2 = 5.5 and Y 0.5 × 6 + 0.5 × 6 = 6. Weights 0.8 and 0.2 give X 7.6 and Y 6. Both assigned costs 2 and 3 fit budget 3. This is a one-horizon common-score comparison, not an arithmetic mean over a changing sequence of future years.

If the objective is to maximise the lowest supplied score, Y’s 6 exceeds X’s 2. If it is to maximise the expected score under the 0.8 wetter weight, X’s 7.6 exceeds Y’s 6. A complete real decision would also need justified predictions, relevant missing scenarios, social and ecological constraints, and a legitimate process for deciding which criterion to use.

Check your understanding

Why can a positive total net 14 coexist with a distribution concern in the first fictional plan?
Show reasoning
The wider group’s +18 outweighs the local group’s −4 in the aggregate. The sum hides who loses. It does not describe within-group differences, participation or recognition, and it cannot by itself establish that the distribution or decision process is acceptable.
Does the higher expected score 7.6 for X demonstrate that the wetter scenario really has probability 0.8?
Show reasoning
No. The 0.8 weight is stipulated, so 7.6 is conditional on it and on the assigned outcomes 9 and 2. Evidence about scenario likelihoods would be an additional input. A calculated conditional score cannot verify the assumption used to calculate it.
Why can Y be preferred by the worst-case criterion while X is preferred by the 0.8-weighted expectation?
Show reasoning
The criteria ask different questions. Y’s lowest supplied outcome is 6 rather than X’s 2, while X’s weighted average is 7.6 rather than Y’s 6 under those weights. The comparison exposes a trade-off; it does not choose society’s goals, acceptable risks or complete set of scenarios.

What to carry forward

State the ecological and social outcomes, whose experience is counted, the uncertainty assumptions and the criterion before treating a conservation ranking as a decision.

References

Resources supporting this lesson’s explanations and examples.