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When the lab disagrees with the lists
A cone-calorimeter number is not a planting list, and a planting list is not allowed to erase it. White, Weise, Mackes, and Dibble 2002 tested Juniperus monosperma (labeled Utah juniper, UJUN) at 25 kW/m². Table 4 reports 76% foliage moisture, green-sample peak heat release 228 kW/m², and dry-sample effective heat of combustion 18.7 MJ/kg. That is direct fire evidence. Direct fire evidence is never silently outvoted by curation.
You are looking at an oneseed juniper in a dry lot and at a Firewise PDF that might still call some junipers “use with care.” This site’s record for the species is avoid, limited-evidence, because that 2002 paper is currently the only lineage on the record. If a list later recommends it, the badge becomes conflict. It does not become on-list.
Why it matters
Embers land in foliage. Homeowners are told to avoid highly flammable vegetation. The 2002 paper exists because lists were not enough. A later horticultural list that likes the blue berries does not get to delete Table 4. See what limited evidence means.
How it works
The paper is Cone Calorimeter Testing of Vegetation: An Update (USDA Forest Service). The cone calorimeter measures heat release by oxygen consumption. The authors cite ASTM 1999 for the apparatus. California nursery plants and a later Colorado sampling were tested.
The Colorado plants include Rocky Mountain juniper (Juniperus scopulorum, RMJU) and Utah juniper (Juniperus monosperma, UJUN). Those are different species. Do not merge them because both are called juniper.
Table 4 (25 kW/m², Bonferroni-adjusted means) puts UJUN at the top of the green PHRR list: moisture 76%, PHRR 228 kW/m², group A. Douglas-fir and Rocky Mountain juniper share that high group. Dry-sample EHOC for UJUN is 18.7 MJ/kg. The authors write that the two junipers, lodgepole pine, and Douglas-fir had significantly higher EHOC than gambel oak, chokecherry, snowberry, and mountain mahogany.
That is a lab lineage. Curation lists vote separately. If they disagree, the record conflicts. If they are absent, the lab still classifies, labeled limited-evidence. That is the rule in content doctrine §2.
The paths
| If this happens | What the record does |
|---|---|
| Lab only (current J. monosperma record) | Avoid, limited-evidence |
| Lab avoid + list recommend | Conflict. The lab stays visible |
| Lab avoid + list avoid | Avoid, and the reason can thicken past limited-evidence |
| List recommend and no lab | On-list or limited-evidence from the list alone — until a lab row lands |
What people mix up
- Treating limited-evidence as “the lab was weak.” The stack is thin. The test is not.
- Letting a longer Firewise list outvote Table 4.
- Merging J. monosperma with J. scopulorum because both are junipers.
- Treating “Utah juniper” in the paper as a Utah building-code fact. It is the authors’ common name for the Colorado sample of J. monosperma.
- Planting it in Zone 0.
How to check
- Open Juniperus monosperma. Read the White 2002 row.
- Open the PDF. Table 4, UJUN, 228 kW/m², 18.7 MJ/kg.
- If a local list recommends the species, it does not delete the lab. It adds a lineage.
- Do not plant in Zone 0.
Limits
This page quotes Table 4 of the opened 2002 PDF. It does not quote every California species in Tables 1–3. It does not merge other Juniperus records. It does not make the tree noncombustible. Moisture was measured at Colorado State University on ovendried samples, as the paper states.
Related records
- Juniperus monosperma
- What limited evidence means
- Why rosemary is disputed
- Fire-resistant does not mean noncombustible
- Juniper or redcedar
Questions
Can a Firewise list take oneseed juniper off avoid?
Not silently. Direct fire evidence is never outvoted by curation. White and colleagues 2002 placed Juniperus monosperma in the high peak-heat-release group of their Colorado cone-calorimeter tests. If a later list recommends the species, the record becomes a conflict. It does not become on-list by majority of lists.
What did the 2002 paper actually measure?
Cone calorimeter tests (ASTM E 1354 apparatus, as used in the paper’s ASTM 1999 citation) at 25 kW/m². For the Colorado sampling, Table 4 lists Utah juniper (Juniperus monosperma, UJUN) at 76% moisture, green PHRR 228 kW/m² (Bonferroni group A), and ovendried EHOC 18.7 MJ/kg.
Is Utah juniper the same as Rocky Mountain juniper?
No. The paper tested both. Rocky Mountain juniper is Juniperus scopulorum (RMJU). Oneseed juniper is Juniperus monosperma (UJUN). Do not merge the taxa.
Why is the plant limited-evidence if the lab is strong?
Limited evidence means one independent lineage classified it. The 2002 paper is that lineage. Thin stack, not a weak test. See what limited evidence means.
Can I plant it in Zone 0 if I prune it?
No. Zone 0 is not a planting list. This page does not make a juniper noncombustible.