Case 3: Liberty Hill Protected Post Oak (20 in DBH)

STATUS: OA-RCA-v2:LBH-QS-309 | drafts complete: 1/1 | unverified citations: 0

# LEO-RCA Profile 01 Evidentiary Stewardship Brief (LBH-QS-309)

## Slot 1: Epistemic Status & Workstream Header
- **Workstream ID:** `OA-RCA-v2:LBH-QS-309`
- **Schema & Profile:** `RCA_v2` / `LEO-RCA-Profile-01`
- **Declared Epistemic Gaps:** `0`

## Slot 2: Sovereign Airlock & Fiduciary Boundary
- **Local Execution Airlock:** Computed deterministically in zero-dependency ECMAScript Modules with zero cloud runtime telemetry.
- **Fiduciary Separation:** Diagnostic biomechanics are decoupled from timber removal bidding. Municipal permit applications and site work require direct owner and credentialed arborist sign-off.

## Slot 3: Point-of-Use Resolution
- **Subject Specimen:** *Quercus stellata* (Post Oak), tag `LBH-QS-309`
- **Geospatial Anchor:** Plus Code `8624M38F+4X` (Lat `30.67`, Lng `-97.93`)
- **Governing Municipal Code:** Liberty Hill Unified Development Code (UDC) § 6.07.01 (Tree Preservation and Mitigation), Ord. 09-O-02 / 22-O-04.06-01 (Liberty Hill, TX (tx-liberty-hill))
- **Point-of-Use Terms:** `DBH` = Diameter at Breast Height (4.5 ft); `t/R` = outer sound wood shell thickness divided by trunk radius (Mattheck 0.30 threshold); `CRZ` = Critical Root Zone; `SRZ` = Structural Root Zone windthrow plate; `STIM` = Soil and Tree Integrated Monitoring.

## Slot 4: Answer-First Verdict, Phased Triage & Physical Falsifier
- **Headline Verdict:** Preserve Post Oak (LBH-QS-309): the outer living wood cylinder exceeds the 0.30 Claus Mattheck stability threshold and qualifies for phased rhizosphere stewardship rather than removal.
- **Structural Truth:** The living wood cylinder retains a 8.1 cm outer shell across a 25.4 cm trunk radius (t/R = 0.32, above the 0.30 Claus Mattheck hollow-shell buckling threshold), anchored by a 9 ft (2.74 m) Structural Root Zone windthrow root plate.
- **Statutory & Seasonal Truth:** Under Liberty Hill Unified Development Code (UDC) § 6.07.01 (Tree Preservation and Mitigation), Ord. 09-O-02 / 22-O-04.06-01 (Liberty Hill, TX (tx-liberty-hill)), this 20 in DBH specimen is classified as Protected with a statutory CRZ = 20 ft (6.1 m). No permit-triggering work on protected trees. Seasonal Ceratocystis fagacearum (Oak Wilt) vector precautions apply: avoid non-emergency oak pruning February through June and seal all fresh wounds within 10 minutes.
- **Stewardship vs. Liquidation:** Preserving this living canopy asset retains $69,172 in 200-year holobiont equity ($5,127 classical CTLA depreciated timber appraisal and $4,500 municipal cash-in-lieu mitigation exposure if destroyed). Day-1 Stage 1 preservation triage starts at $1,771 compared against a one-time removal bid of $2,460, while the 5-year stewardship program delivers a 5.98x net practitioner margin multiplier over liquidation.
- **Physical Falsifier (STIM Kill Criterion):** If Year-1 upper canopy dieback exceeds 15% or epicormic sprouting exceeds 25% of main scaffold length, halt further root-collar disturbance and apply supplemental mycorrhizal extract drench.

### 3-Stage Phased Stewardship Triage (Total 5-Year Gross: $8,553 | Practitioner Net: $4,704)
- **Stage 1 (Day 1 (Immediate Triage)): Root-Collar Excavation, SGR Relief & Structural Audit** | Client investment: **$1,771** | Practitioner net: **$1,027**
- **Stage 2 (Months 6 to 18): 150 psi Radial AirSpade Decompaction & Biochar-Fungal Inoculation** | Client investment: **$3,730** | Practitioner net: **$1,912**
- **Stage 3 (Years 2 to 5): Native Companion Guild & Year-1 / Year-5 STIM Verification** | Client investment: **$3,052** | Practitioner net: **$1,765**

## Slot 5: Three-Tier Evidence Boundary & Oracle Provenance Anchors
### Tier 1: Deterministic Engine & Measured Biometrics
- Measured DBH (in): [[oracle:rca.structural.dbh_in=20]]
- Mattheck Sound Shell Ratio (t/R): [[oracle:rca.biomechanics.t_over_r=0.32]]
- Critical Root Zone Radius (ft): [[oracle:root_zone.crz_ft=20]]
- Structural Root Zone Radius (ft): [[oracle:root_zone.srz_ft=9]]
- 200-Year Holobiont Living Equity (USD): [[oracle:rca.valuation.holobiont_200yr_usd=69172]]
- CTLA 10th Ed. Depreciated Value (USD): [[oracle:rca.valuation.ctla_depreciated_usd=5127]]
- Municipal Cash-in-Lieu Exposure (USD): [[oracle:ordinance.cash_in_lieu_usd=4500]]
- Day-1 Stage 1 Triage Price (USD): [[oracle:rca.triage.stage1_usd=1771]]

### Tier 2: Literature & Statutory Calibration
- Claus Mattheck hollow-cylinder buckling criterion (t/R >= 0.30); Australian AS 4970-2009 SRZ; ANSI A300 Part 5 root-zone management; Nowak (1994, 2006) allometrics; Liberty Hill Unified Development Code (UDC) § 6.07.01 (Tree Preservation and Mitigation), Ord. 09-O-02 / 22-O-04.06-01.

### Tier 3: Explicit Unverified Epistemic Boundaries
- Zero unverified statutory or instrument gaps recorded in this brief.

## Slot 6: Cryptographic SHA-256 Receipt
- **Canonical Assessment SHA-256:** `2bd6bb1783a760e3b44b99e38d3ef1adfc046e03da694fec7b004f1b05a9004b`