---
title: where the dollar per acre comes from
canonical_url: https://ensurance.app/guide/where-the-dollar-per-acre-comes-from
markdown_url: https://ensurance.app/guide/where-the-dollar-per-acre-comes-from.md
subtitle: "ESVD, FEMA, and a hundred ways to put a number on a year of work"
category: esv
---

# where the dollar per acre comes from

*ESVD, FEMA, and a hundred ways to put a number on a year of work*

An **ecosystem service value per acre** is a borrowed measurement. Somewhere, a study put a dollar figure on a year of one kind of work done by one kind of place: a wetland's flood storage, a forest's water filtration above a city, a marsh's storm buffering on a coast. That figure, divided by the acres that did the work, is a value record. A valuation of a different place of the same kind borrows it, adjusts it, and says where it came from. The method has a name, benefit transfer, and two published sources hold most of the records.

Take a strip of salt marsh on a bay. The marsh is a stock: a living system with an extent, a character and a condition. What it does in a year, blunting the surge, holding the shore, feeding the fishery, is its flow. RealValue makes the flow legible in dollars beside what the stock costs to hold. FEMA's 2022 values put dollars per acre per year on coastal wetlands for hazard risk reduction and for existence value, among others; they list a service called cultural value and calculate no figure for it. The marsh does all of that whether or not any of it is priced. [Ensurance](/?from=guide) funds the marsh. It is not the record.

:::johnson
**a dollar per acre per year is a borrowed measurement, and it says where it was borrowed from.** — ESVD held 9,500 value records from more than 1,100 studies in its 2020 update. FEMA's 2022 values price nine land covers and fourteen services inside the benefit-cost toolkit FEMA uses when it reviews mitigation money.

[how the number is built →](/guide/how-ecosystem-services-get-a-number?from=guide)
:::

## what a value record is

A value record is one study's estimate of one service from one kind of ecosystem, normalized to a unit area and a year. The databases keep the details of the study and the valuation method with it. It does not carry a claim that the figure is what the place is worth. The phrase "ecosystem service value" is used throughout the works the review read and defined in none of them; the Field Manual defines it as the quantifiable benefit, monetary or not, that humans derive from the functions and processes of ecosystems.

The word to hold onto is estimate. A value record is what a method produced under a set of assumptions, somewhere else. Transferring it here adds the assumption that here is enough like there. Good practice names the method and the source, adjusts for the differences it can measure, and keeps the annual reading rather than collapsing it into a lump sum.

## the two sources

| | Ecosystem Services Valuation Database (ESVD) | FEMA Ecosystem Service Value Updates (2022) |
|---|---|---|
| Who | The Ecosystem Services Partnership with the Foundation for Sustainable Development; de Groot, Brander and Solomonides led the 2020 update | The US Federal Emergency Management Agency, with figures drawn from the valuation literature |
| What it holds | 9,500 value records from more than 1,100 studies, across biomes and regions, in the 2020 global update; the successor to the TEEB database of over 1,300 data points from 267 case studies | A published set of values in dollars per acre per year for nine land cover types and fourteen services with calculated values, inside the Benefit-Cost Analysis Toolkit |
| Filed under | TEEB's biomes and about two dozen services, each record with its valuation method | Forest, urban green open space, rural green open space, riparian, coastal wetlands, inland wetlands, coral reefs, shellfish reefs, beaches and dunes |
| What it is for | Research and policy; monetary values for ecosystem services across the world's biomes | Counting a nature-based project's benefits in the toolkit that federal hazard mitigation projects run through; recent policy also widened eligible nature-based solutions |
| What it leaves out | A global database is thin where studies are thin; a record from one coast is not a record from yours | Anything outside the nine land covers has no FEMA row; of the twenty-three services it lists, nine have no calculated value, among them cultural value, soil formation, soil quality, nutrient cycling and water storage |

Two smaller sources sit behind them. Environment Canada's EVRI and Texas A&M's BlueValue hold thousands of environmental and health valuation studies, and FEMA drew on studies like those. The point of naming all four is that each figure names its study. A reader can go and find it.

## how a figure is made

The methods are older than the databases, and each answers a different question. Four families. What people already pay: the market price of the timber, the travel cost people bear to reach a place, the premium a house carries for standing beside a park. What it would cost to replace or restore: the treatment plant that would do what the forest does, the seawall that would do what the marsh does. What damage is avoided: the flood that the wetland held, the slope that did not fail. What people say: contingent valuation and choice experiments, which ask what people would pay or accept. Beside these, production functions model how much crop the pollinators add, and meta-analysis pools many studies into one function and transfers that. The review behind this framework counted more than a hundred such methods across the ecosystem services literature and more than twenty-five on the real asset side; contingent valuation, hedonic pricing, replacement cost and travel cost each appeared in nine of the frameworks read.

Which method made a figure matters when you borrow it. A replacement-cost figure for water filtration is a statement about what a plant would cost; a willingness-to-pay figure for a view is a statement about a survey. The source study records the method, so the reader can weigh it.

## the value table

RealValue carries the borrowed figures in a value table: the fifteen stocks down one side, the flows across the top, each cell a dollar figure per acre per year with its source. Three things about it are worth knowing.

It is not full. Where no value record exists for a flow in a stock, the cell is blank. A blank is not a zero; it means no one has measured that work in that kind of place yet, and the valuation carries the blank rather than a guess.

It is versioned. The manual and the code say fifteen stocks and nineteen flows. The Field Manual's RealValue page lists eighteen RealValues, because food, energy and raw materials are carried on the income side when they are sold. The live table holds twenty-one flow definitions: sixteen that carry a public-goods value, two that carry income, and food, energy and raw materials carried as income when they are sold. The snapshot read in October 2026 held 208 entries. Each count describes a version of the same account.

It is annual. Many studies print a lump sum, the present value of years of a service discounted to today. RealValue keeps the dollars-per-acre-per-year reading, because an annual figure can sit beside the annual income a property already earns, and both can sit over the cost of the real asset. [Flows over stocks](/guide/flows-over-stocks?from=guide) is where that ratio is built. Each flow's page at [/natural-capital/flows](/natural-capital/flows?from=guide) is where the rows are read.

## what the figure cannot carry

Transfer error is real. A record from a Mediterranean marsh transferred to a Gulf one carries the difference between them unmeasured. A record from 2005 carries 2005 prices and a 2005 understanding of the service. A contingent-valuation figure carries the population that was surveyed. None of this makes the record useless; it makes it a record, to be adjusted where the difference can be measured and flagged where it cannot.

And the figure is not the worth. The marsh is not worth its hazard-risk-reduction row. The row is what one method, in one study, in one place, estimated a year of that work at, borrowed here. [A valuation is not the worth](/guide/a-valuation-is-not-the-worth?from=guide) holds that line for the whole account. The next step is the one that makes the borrowed figure about this place: extent, character and condition.

## frequently asked questions

### what is an ecosystem service value per acre?

A dollar figure for one year of one ecosystem service from one acre of one kind of ecosystem, estimated by a study and normalized so it can be compared and transferred. Published sources such as ESVD and FEMA's 2022 ecosystem service values hold these figures with their methods and sources.

### what is benefit transfer?

Using a value estimated at one site to estimate the value of the same service at another site of the same kind, adjusted for measurable differences. It is how parcel-level ecosystem service valuations are commonly done, because primary studies are expensive and rare.

### are ESVD and FEMA values reliable?

Each record is traceable to a study and a method, and FEMA's figures are the ones its own benefit-cost toolkit carries. They are estimates with transfer error, not measurements of this parcel, and a valuation should say which record it used and why.

## next

The number meets the place: [the same acre is not the same acre](/guide/the-same-acre-is-not-the-same-acre?from=guide).

If you want to see what a source watershed's filtration or a marsh's surge protection has been valued at elsewhere, the flow pages at [/natural-capital/flows](/natural-capital/flows?from=guide) are where to start, and [investors](/solutions/investors?from=guide&topic=stocks-and-flows) shows how the account is used. If you can already name the place, [tell us which](/contact?from=guide&topic=stocks-and-flows).

## sources

[BASIN Field Manual, Ecosystem Service Values](https://docs.basin.global/appendix/selected-value-types-and-valuation-methods/ecosystem-service-values) — the ESV definition, the sources, the methods, and the annual versus lump-sum reading.

[BASIN Field Manual, Valuation Methods](https://docs.basin.global/appendix/value-types-and-valuation-methods/valuation-methods) — more than 100 ecosystem service methods and more than 25 real asset methods counted; the four that appeared in nine frameworks.

[BASIN Field Manual, FEMA Ecosystem Service Value Updates](https://docs.basin.global/appendix/ecosystem-services-classification/ecosystem-services-frameworks/fema-ecosystem-service-value-updates) — the twenty-three services listed, the fourteen with calculated values, and the policy changes.

[de Groot, R., Brander, L., Solomonides, S. 2020. Update of global ecosystem service valuation database (ESVD). Final report.](https://www.es-partnership.org/wp-content/uploads/2020/08/ESVD_Global-Update-FINAL-Report-June-2020.pdf) — 9,500 value records, 1,100+ studies, the TEEB lineage.

[FEMA. 2022. Ecosystem Service Value Updates.](https://www.fema.gov/sites/default/files/documents/fema_ecosystem-service-value-updates_2022.pdf) — nine land cover types, fourteen priced services, the Benefit-Cost Analysis Toolkit.

[Natural capital, the ensurance manual](/manual/natural-capital?from=guide) — the value table, its sources, and the data sources list.

[BASIN Field Manual, FLOWS Values](https://docs.basin.global/realvalue/the-realvalue-of-natural-capital/realvalues/flows-values) — the eighteen RealValues, the annual reading, and why food, energy and raw materials are carried as income.

## the series

1. [the stocks and flows of natural capital](/guide/the-stocks-and-flows-of-natural-capital?from=guide) (read first)
2. [every acre is one of fifteen things](/guide/every-acre-is-one-of-fifteen-things?from=guide)
3. [nineteen things a place does](/guide/nineteen-things-a-place-does?from=guide)
4. [where the dollar per acre comes from](/guide/where-the-dollar-per-acre-comes-from?from=guide)
5. [the same acre is not the same acre](/guide/the-same-acre-is-not-the-same-acre?from=guide)
6. [flows over stocks](/guide/flows-over-stocks?from=guide)