LIT_077: Schreiber et al. (2021) — Quantifying the Foodshed: A Systematic Review of Urban Food Flow and Local Food…

LIT_077: Schreiber et al. (2021) — Quantifying the Foodshed: A Systematic Review of Urban Food Flow and Local Food…

Source

doi:10.1088/1748-9326/abad59 — original publication (opens in a new tab; the file is not redistributed)

Schreiber et al. (2021) — Quantifying the Foodshed: A Systematic Review of Urban Food Flow and Local Food Self-Sufficiency Research

The methodology paper behind the model's foodshed SSL — and the caveat that theoretical local-food self-sufficiency ≠ actual

Peer-reviewed PRISMA systematic review (McGill/Linköping, Environ. Res. Lett. 16 023003, published 21 Jan 2021; received May / accepted Aug 2020, hence the “2020” citation in CR_003) of 42 empirical foodshed studies (1979–2019) that quantify local food self-sufficiency (LFS), food supply, or food flows. This is the primary behind the wiki’s SSL_foodshed land-based food-self-sufficiency method (self_sufficiency_calculation): it defines the calculation forms NI uses — the self-sufficiency threshold (ST = production/consumption × 100), its inverse (IST), and foodshed size (land/radius needed to meet demand) — and the three functional units (weight, nutrition, land). Its load-bearing contribution for Neobiome is a methodological warning: a region can have high theoretical LFS potential but low actual LFS, because a high production:consumption ratio cannot be realised without processing/storage/transport infrastructure, economic incentive to source locally, seasonality management, and consumer preference — so a food-SSI computed from land-and-yield alone (as the model does) systematically overstates achievable food self-sufficiency. ⚠ It is a global urban-foodshed methodology review, not NZ data and not a community-scale study — its numeric results (LFS %, foodshed radii) are values it reports from the 42 reviewed studies (all Global North: N. America n=19, Europe n=13, Asia n=6), not original measurements, and cities ≠ remote off-grid communities. Use it for the METHOD and the caveat, not as a data source.

Summary

Schreiber, Hickey, Metson, Robinson & MacDonald (2021), “Quantifying the foodshed”, is an open-access topical review in Environmental Research Letters (16, 023003) conducting a PRISMA systematic review of the empirical literature that quantifies urban and regional foodsheds. From an initial 1,271 documents (ISI Web of Knowledge + Scopus, searched 17 Sep 2019) the authors screened 829 and retained 42 peer-reviewed studies from 1979–2019 that map food flows or estimate the potential for local food self-sufficiency (LFS). They classify these into three foodshed types: (1) Capacity studies (estimate LFS potential or the local foodshed size required to meet demand), (2) Flow studies (trace food movements and embodied resources/emissions), and (3) Hybrid studies (combine both to study import/export/LFS dynamics). Capacity studies are the most common. They develop a synthetic framework with ten methodological criteria and a decision tree of calculation methods — the self-sufficiency threshold (ST), inverse self-sufficiency threshold (IST), and foodshed size — across three functional units (weight, nutrition, land). The central finding is that the lack of a coherent methodological framework and research agenda limits cross-study comparison and knowledge cumulation, illustrated by studies of the same region returning very different LFS results because of differing optimisation and allocation assumptions. The review documents a strong Global North bias (underrepresentation of the rapidly-urbanising Global South), a scholarship gap between 1979 and 2007, and recurring data challenges (scarce/unreliable subnational crop-yield, soil, consumption and food-flow data; rare use of sensitivity analysis; seasonality treated statically). Its stated core priorities are to explore the interplay between LFS capacity and interregional food trade, and to use Hybrid methodologies to capture dependency relationships. context: both — it feeds I02 (the food-self-sufficiency indicator methodology, NI) and the self_sufficiency_calculation concept (the SSL_foodshed method), and supports the thesis food-systems / localism-vs-globalisation and food-resilience argument. Read verbatim via pdftotext -layout (15 pp + references); every figure quoted traces to the raw → data_quality: high (single authoritative peer-reviewed primary, not NZ-specific, not independently triangulated).

Key claims

- claim: "We conduct a review of 42 peer-reviewed publications on foodsheds (identified from a subset of 829 publications) from 1979 to 2019 that quantify LFS, food supply, or food flows on the urban or regional scale. We define and characterize these studies into three main foodshed types: (1) agricultural capacity, which estimate LFS potential or local foodshed size required to meet food demands; (2) food flow, which trace food movements and embodied resources or emissions; and (3) hybrid, which combine both approaches and study dynamics between imports, exports, and LFS. LFS capacity studies are the most common type."
  source_location: "Abstract, p.1; Section 3.1 Foodshed study types, p.4"
- claim: "The lack of a coherent methodological framework and research agenda limits the potential to compare different cities and regions as well as to cumulate knowledge. Core research priorities from our review include the need to explore the interplay between LFS capacity and interregional food trade (both imports and exports) for foodsheds. Hybrid methodologies are particularly relevant to examining such dependency relationships in food systems by incorporating food flows into LFS capacity assessment."
  source_location: "Abstract, p.1"
- claim: "Foodshed studies used three main functional units for food consumption and production values: weight, nutrition, and land. Food production = crop yield x functional unit (e.g. hectares); Food consumption = population x functional unit per capita (e.g. servings); Embodied resources or emissions (RE) = (RE / crop yield) x food quantity."
  source_location: "Section 3.1 Results, p.5; Figure 4, p.8"
- claim: "Capacity calculation approaches were grouped into three categories. Self-sufficiency threshold (ST) = Food production / Food consumption x 100, where a value >=100% implies high LFS potential (surplus). Inverse self-sufficiency threshold (IST) = Food consumption / Food production x 100, where a value <100% implies high LFS potential. Foodshed size determined how much local land is needed to meet food demands and the radius defining the maximum distance a population must travel to meet those food needs."
  source_location: "Section 3.1.1 Capacity studies, pp.4-5; Figure 3 synthetic framework, p.8"
- claim: "With current patterns of food production and consumption, just one-third or less of the world population's food demand can be supplied by local sources (Kriewald et al 2019, Kinnunen et al 2020)."
  source_location: "Section 1 Introduction, p.2 (Schreiber et al. reproducing Kriewald 2019 / Kinnunen 2020, not an original result)"
- claim: "A region can have a high theoretical LFS potential but low actual LFS (Zhou et al 2012). Without food flow analysis, high LFS potentials could result in misleading conclusions and policy recommendations. A high LFS potential cannot be exploited if neither adequate processing, storage, and transportation infrastructure nor the economic incentive to source locally prevail in a region. Most Capacity studies neglected social preferences, assuming farmers will supply the closest population centre and that citizens will refrain from buying imported foods."
  source_location: "Section 3.1.3 / Section 4.1, p.8, p.11; Section 4.2.1 Research priorities, p.13"
- claim: "PRISMA process: 1,271 documents were identified through the initial search in ISI Web of Knowledge (n=511) and Scopus (n=760) databases (September 17, 2019); 442 duplicates were removed and 829 articles screened; 193 were reviewed for eligibility; the final sample includes 37 studies identified through the PRISMA process plus an additional five identified through snowball sampling (42 total)."
  source_location: "Section 2 Methods, p.3; Figure 1 PRISMA diagram, p.4"
- claim: "Foodshed research has been concentrated in a few regions, mainly North America (n=19), Europe (n=13), and Asia (n=6). The majority of cases found were from cities or regions in the Global North, with underrepresentation of rapidly urbanizing regions of the Global South. There is a gap in scholarship between 1979 and 2007, indicating a lack of empirical advancement despite important conceptual and theoretical contributions."
  source_location: "Section 3.2 Descriptive statistics, p.9; Abstract, p.1"
- claim: "Two priority research areas are identified: Priority #1 — how do physical and social barriers interact in local food systems (city size vs physical and social capacity for localization, which remains empirically scarce); Priority #2 — how are food flows linked with other urban material flows and embodied resources (extending analysis to input origins, wastesheds, nutrient loops, and circular-economy integration)."
  source_location: "Section 4.2.1 Research priorities and policy areas, p.13"
- claim: "Data challenges: Capacity study authors mentioned scarce, unreliable, and fragmented data on crop yields and soil properties; aggregation across administrative units introduces uncertainty; few reviewed studies used sensitivity analysis. Many foodshed studies (particularly Capacity studies) treat food supply and agricultural capacity as static, and seasonality is rarely addressed despite agricultural seasons being crucial determinants of type, quantity, and availability of foods."
  source_location: "Section 4.2.2 Data challenges and uncertainties, pp.13-15"
- claim: "Illustrative Capacity example (Joseph et al 2019, Hamburg and North Germany): estimated high potential for LFS of 34-57% within a 50 km radius and 74-100% within a 100 km radius; available agricultural land and per capita meat consumption have large impacts on LFS. Illustrative Hybrid example (Hara et al 2013, Osaka city region, Japan): self-sufficiency by buffer zone was 20 km—5.7% of population fed, 40 km—21.7%, 60 km—50.0%, 80 km—68.5%; 80% of embodied energy in nearby prefectures was due to inorganic fertilizer and pesticide application."
  source_location: "Table 2 (Joseph et al 2019), p.6; Table 4 (Hara et al 2013), p.10 — reviewed-study results reported by Schreiber et al., not original measurements"
- claim: "Difficulties in comparing results across the 42 studies are illustrated by studies of the same region: Peters et al (2009) found 34% of New York State's total food demands can be met within 49 km, while Peters et al (2012) found 69% of the State's food needs can be met within 238 km; discrepancies reflect methodological variations in the optimization and allocation models used. For US cities using the foodshed-size method, foodshed sizes ranged from 16 km (Des Moines) to 122 km (Chicago area)."
  source_location: "Section 3.3 Quantitative comparison, pp.10-11; Figure 6, p.11"

Relevance

context: both — this source is the methodological grounding for the Neobiome Intelligence food-self-sufficiency layer (I02 and the SSL_foodshed method on self_sufficiency_calculation), and it supports the thesis food-systems localism/resilience argument.

Neobiome Intelligence — the foodshed SSL method and its overstatement caveat

• This is the primary behind the model’s land-based food-self-sufficiency method. self_sufficiency_calculation already carries a SSL_foodshed = available local agricultural area (ha) / land footprint of food consumption (ha) variant (community food-self-sufficient if SSL ≥ 1.0), currently cited only to the AI syntheses CR_002 / CR_003. Schreiber et al. is the peer-reviewed review those syntheses draw on for it — it defines the foodshed-size method (land + radius to meet demand) and the self-sufficiency threshold (ST = production/consumption × 100) that SSL_foodshed operationalises, and situates them among the three functional units (weight, nutrition, land) NI could adopt. It upgrades the method’s provenance from AI-extracted to a directly-read primary.
• The load-bearing caveat: land-and-yield foodshed SSL overstates achievable food self-sufficiency. The review’s central methodological warning is that a high theoretical LFS potential (a favourable production:consumption ratio) does not translate to actual self-sufficiency, because it is gated by processing/storage/transport infrastructure, the economic incentive to source locally, seasonality, and consumer preference — barriers Capacity studies routinely omit. NI’s food-SSI is exactly a Capacity-style computation (parcel LUC-ha × regenerative veg_yield vs a diet-based land footprint, per the model’s diet-aware food design — model_design.md decision D29 — and D_001), so this is a direct instruction to treat the model’s food-SSI as an upper bound and to surface the infrastructure/seasonality/preference haircut — coherent with the existing “veg-only, staples/fruit/dairy excluded” scope caveat and the LIT_022 note that even 400% vegetable SSI ≠ full food self-sufficiency.
• Seasonality and the static-capacity trap. The review flags that Capacity studies treat agricultural capacity as static and rarely model seasonality, yet season determines the type/quantity/availability of food — off-season perishable demand can only be met by imports or greenhouse horticulture. This validates the model’s move toward a frost-free-window / growing-season refinement (RD_022) and warns against reading an annual-average food-SSI as if production were uniform across the year.
• Functional-unit and comparability discipline. The finding that same-region studies (Peters 2009: 34% within 49 km vs Peters 2012: 69% within 238 km) diverge purely on optimisation/allocation assumptions is a caution that a single food-SSI number is method-sensitive; NI should hold the diet model, yield basis, and land-allocation rule explicit and constant (as the model’s food design does) rather than treat the output as a hard fact.

Thesis — food-systems localism, telecoupling and resilience

• Localism is not automatically more sustainable or more resilient. The review synthesises evidence that local food is not always more resource-efficient (citing Weber & Matthews 2008, Edwards-Jones 2010, Avetisyan 2014) and that specialisation from globalisation can raise resource-use efficiency while carrying other social/environmental costs — a nuance for the thesis’s self-sufficiency argument against a naive “local = better” framing.
• Source diversification as a resilience strategy. Flow-study evidence (Akoto-Danso et al. 2019, two West African cities) shows decentralised/diversified sourcing can spread the risk of food insecurity from environmental shocks (water shortage, extreme weather) and geopolitical crises — supporting the thesis I06 resilience line that a community’s food security depends on managed dependency and diversification, not autarky alone. Foodsheds are “telecoupled”: exports can erode local LFS capacity while imports supplement it.

Research targets

Documents to retrieve

• None. This is a methodology review; its 42 sub-studies are urban-foodshed method papers (Global North cities), not NZ or community-scale data cells worth retrieving for NI. Retrieving them would be off-scope for a remote-community model.

Research gaps

• None new. The review’s own identified gaps (Global-South underrepresentation, subnational data quality, seasonality/temporal modelling) are documented as method caveats above; they qualify how NI reads its food-SSI rather than defining a retrievable NZ target. The standing NZ food-self-sufficiency data work (regenerative veg_yield, livestock benchmarks, diet-diversity land gap) is already tracked on I02 / D02 and needs no addition here.

Notes

Authoritative peer-reviewed primary (IOP Publishing, Environmental Research Letters 16 (2021) 023003, Open Access CC BY 4.0; McGill Sustainability Systems Initiative + NSERC RGPIN-2016-04920), read verbatim via pdftotext -layout (15 pp topical review + references + supplementary-material references) — not AI-prepared, so no retrieval-provenance block is required. Every figure quoted traces to the raw.

Year 2020 vs 2021. The article was received 10 May 2020, accepted 7 Aug 2020, and published 21 Jan 2021 in the 2021 volume; the canonical IOP citation is “Kerstin Schreiber et al 2021 Environ. Res. Lett. 16 023003”. CR_003’s underlying_sources and the RT_028 row cite it as “Schreiber et al. (2020)” (the acceptance year). This page uses year: 2021 (the correct publication year) with the slug/alias trail noting the 2020 form so the CR_003 cross-reference resolves.

⚠ data_quality: high, and why not verified. All 12 key_claims trace verbatim to the raw (the batch rule would permit verified where every figure traces to the raw — it does). But per the corpus/model_design.md §2 definition, verified requires independent triangulation, which this single standing review does not have, and high requires NZ-relevance, which a global urban-foodshed methodology review lacks. It is set to high as the closest honest label — a single authoritative peer-reviewed primary — flagged here for the verifier/human gate. It is method evidence, not a NZ data cell.

⚠ Scope caveat — reproduced figures and urban ≠ community. The quantitative results in the key_claims (the LFS %, foodshed radii, the “one-third of world food demand” figure) are values Schreiber et al. report from the 42 reviewed studies (all Global North cities) or reproduce from other papers (Kriewald 2019, Kinnunen 2020) — they are NOT original measurements, and the review is of urban foodsheds (cities and their rural hinterlands), whereas Neobiome models remote off-grid communities. Do not mine the LFS percentages or radii as if they were NZ or community datapoints; the transferable content is the calculation methods (ST/IST/foodshed-size) and the overstatement/seasonality caveats. The source-page Relevance states this explicitly.

Cross-references (no edits required): completes the open residual of CR_003 (RT_028 sought this exact primary, listed in CR_003’s underlying_sources); the SSL_foodshed method it grounds lives on self_sufficiency_calculation alongside CR_002; connects to the food-SSI overstatement theme already on I02 via LIT_022 (vegetable SSI ≠ full food SS) and LIT_020 (complete food SS rarely achieved). The “Schreiber” here is Kerstin Schreiber (foodshed) — unrelated to the “Schreiber & Hochloff” battery self-consumption study cited in LIT_072 (different author, different field; no dedup conflict).

Connections

Links to

Sources (6): CR_002 · CR_003 · LIT_020 · LIT_022 · LIT_072 · RD_022

Decisions (1): D_001: Neobiome food production — regenerative…

Concepts (1): Self-Sufficiency Calculation Framework

Referenced by

Sources (2): OT_191 · OT_192

Concepts (1): Self-Sufficiency Calculation Framework

SSI indicators (1): I02: Food Security & Sustainable Agriculture