OA Open Arbor v2.1
Open Arbor · Free Instrument for Stewards & Consulting Arborists

See what your tree is holding up before anyone starts a chainsaw.

Conventional tree appraisals treat a hollow 200-year-old oak as depreciated lumber and stop looking at the grass line. Open Arbor reads the living wood cylinder, the underground root plate, the soil sponge, and your city's tree code in one glance. No account, no paywall, and every number can be checked.

Drag any slider to watch structure, soil sponge, and city code update live
Live Oak Living Architecture and Trunk Shell Cross-Section t/R = 0.38
Left: Crown, AS 4970 windthrow plate, ANSI A300 CRZ, 1.5x mycorrhizal sponge & trench line Right: Outer living cylinder vs. Claus Mattheck 0.30 hollow-shell buckling limit
Tape around trunk at 4.5 ft: 94.2 in (7 ft 10.2 in)
Checks protected/heritage status, permit rules, and removal fees
t/R = 0.38 (Sound ≥ 0.30)
Slide to 65% hollow (t/R = 0.35): a trunk two-thirds hollow inside still holds full windload strength above 0.30.
Affects ~283 sq ft of outer feeder roots; specify 150 psi AirSpade trenching rather than mechanical cutting.
Critical Root Zone & Soil Sponge 30.0 ft (9.14 m) 2,827 sq ft CRZ | 6,362 sq ft sponge
Windthrow Root Plate & City Tier 10.5 ft (3.21 m) Heritage (Removal Permit Req.)
200-Yr Living Holobiont Equity $218,609 CTLA: $13,699 | Nowak: $107/yr
Plain-Language Field Verdict · LEO-RCA Answer-First Updates live from primary biomechanics & municipal code

Preserve Live Oak (ATX-QV-101): the outer living wood cylinder exceeds the 0.30 Claus Mattheck stability threshold and qualifies for phased rhizosphere stewardship rather than removal.

At 30 inches DBH (~291 years old), this Live Oak retains a 14.5 cm living outer cylinder (t/R = 0.38, above Claus Mattheck's 0.30 buckling threshold) anchored by a 10.5 ft structural root plate. Under Austin, TX (Austin LDC § 25-8-604), it classifies as Heritage with a 30.0 ft Critical Root Zone and 10% proposed root-zone trenching. Its underground mycorrhizal zone captures 3,962 gallons in a 1-inch rain, and Day-1 Stage 1 root-collar relief ($2,261) costs less than a one-time chainsaw bid ($3,140).

Physical check: If Year-1 terminal shoot extension remains below 6 cm or upper crown dieback exceeds 12%, re-inspect for subsurface utility trench root severance or oak wilt vascular streaking.
Future A · One-Time Chainsaw Liquidation
$3,140 one-time removal bid
  • City code exposure: $6,000 city mitigation fee
  • Canopy & watershed loss: $218,609 living equity lost (CTLA lumber value: $13,699)
  • Result: Stump heat island, lost stormwater sponge, and high-hazard crane/rigging exposure.
Future B · Phased Regenerative Stewardship
$2,261 Day-1 Stage 1 root-collar relief
  • Immediate homeowner savings: $879 less than Day-1 removal
  • Living soil sponge kept: 3,962 gal / 1-in storm + 4,669 gal SOM reserve
  • Working arborist upside: 6.35x higher 5-yr arborist net margin ($6,382 vs $1,005)
Citation: Austin LDC § 25-8-604 | Live Oak (~291 yrs) | Mattheck t/R = 0.38
Open Full Studio & Print Sheet
Field Wisdom & Proof

Why Tree Stewards and Working Arborists Share Open Arbor

Plain-language clarity sits on the surface for property owners and neighbors. Lift the veil on any card, or switch Veil: Deep Proof in the top bar, to inspect the primary physics, soil hydrology, and municipal code logic underneath.

1 · Cylinder Physics

Hollow Does Not Mean Condemned

A mature tree is built like a steel mast, carrying bending wind stress in its outer ring of living sapwood rather than its oldest center heartwood. When an outer sound shell holds at least 30 percent of the trunk's radius and the root flare stays intact, a hollow veteran oak retains its full structural windload capacity.

Under the Veil Mattheck t/R ≥ 0.30 & AS 4970 Equations
t/R = t_sound_shell_cm / R_trunk_radius_cm ≥ 0.30
R_SRZ (m) = max(1.5, (D_flare_m × 50)^0.42 × 0.64)

Grounded in Claus Mattheck & Helge Breloer (1994), The Body Language of Trees, and Australian Standard AS 4970-2009 § 3.3.5. Executed in src/core/rcaEngine.js and src/core/rootZone.js, where UNJUSTIFIED_REMOVAL blocks condemning a tree with t/R ≥ 0.30 without sonic tomography evidence.

2 · Subterranean Life

The Tree Begins Underground

Most declining yard trees are starving or suffocating beneath compacted turf grass and soil piled high against their root collar. Unburying the root flare with supersonic air, relieving girdling roots, and rebuilding a fungal woodchip and biochar sponge restores canopy vigor while drinking thousands of gallons of storm runoff.

Under the Veil AirSpade Geometry, NRCS Sponge & Nowak Models
V_trench = N_spokes × L_m × W_m × D_m (150 psi pneumatic)
Storm_1in_gal = A_TIZ_m2 × 25.4 L/m2 × 0.264172 gal/L
AGB_kg = exp(-2.0773 + 2.3323 × ln(DBH_cm))

Computed in src/core/soilFunction.js (NRCS ~20,000 gal/acre per 1% SOM above baseline; strict provenance validation) and src/core/ecosystemBenefits.js (Nowak 1994, Cairns et al. 1997, Xiao et al. 2000, McPherson & Simpson 1999).

3 · Aligned Practice Economics

Saving Trees Pays Better Than Cutting Them Down

The Regenerative Consulting Arborist (RCA) model breaks the industry trap where an arborist only gets paid if a tree comes down. Phased stewardship starts with an affordable Day-1 root-collar triage that costs less than removal, while building a 5-year relationship that earns the practitioner 4x to 6.5x higher net margin.

Under the Veil Live 3-Stage Triage, Holobiont Equity & 8-City Statutes

Computed live by computePhasedStewardshipTriage (src/core/leoRcaEngine.js), computeRegenerativePracticeEconomics, and computeHolobiontValuation (src/core/rcaEngine.js), paired with declarative municipal statutes conforming to schemas/municipal-ordinance.schema.json.

Have a tree company coming out this week, or run an arboriculture practice yourself?

Homeowners send the pre-computed brief before the estimate so everyone looks at the same physics and city code. Working arborists use the Field Studio offline in the truck to print signed 1-page client determination sheets at zero cost.

Browse 5 Real Case Studies Compare 8 City Tree Codes
Commons Ecosystem

The Four Living Pillars of the Open Arbor Alliance

Instead of a rented cloud subscription that locks up community tree records behind a monthly login, Open Arbor is built as a public instrument you own, inspect, and pass forward across generations of land care.

Pillar 1 · Individual Tree

Open Arbor (openarbor.org)

Field diagnostic studio for arborists, municipal reviewers, and property stewards. Evaluates root protection zones, hollow-shell stability, municipal permits, phased soil care, and printable evidentiary reports offline on any phone or laptop.

  • ANSI A300 Part 5 CRZ, AS 4970 SRZ, and BS 5837 protection zones
  • Claus Mattheck shell stability and pneumatic root-collar prescriptions
  • 200-year living biological equity alongside classical CTLA appraisal
Open Field Studio Read Case Studies
Pillar 2 · Living Collections

Open Arboretum

Living tree collections, native nursery propagation protocols, seed-to-canopy batch provenance, and community phenology observations anchored to verified iNaturalist taxonomy for host trees, mycorrhizal fungi, and understory guilds.

  • Taxonomic anchoring across oaks, pecans, conifers, madrones, and symbiont fungi
  • Mother-tree germplasm provenance and local seed-lot lineage tracking
  • Shared observation loop connecting backyard stewards and certified arborists
Explore Companion Guilds iNaturalist Commons
Pillar 3 · Stand & Watershed

Open Forest

Stand-level terrestrial and aerial LiDAR point cloud processing, tree-ring chronology, forest growth simulation, bioacoustics, and wildfire behavior modeling curated into a 41-tool open scientific workbench.

  • 41 audited open-source forestry tools with local CLI recipes and evidence grades
  • Direct attribute mapping from 3D point clouds into Regenerative Consulting Arborist dossiers
  • QGIS and OGC CRS84 GeoJSON interoperability with zero proprietary file lock-in
Explore 41-Tool Workbench
Pillar 4 · 200-Year Tenure

Open Sanctuary

Multi-decade parcel stewardship built for a 200-year horizon (2026 to 2226). Combines 5-dimension Sanctuary Scorecards, de-duplicated multi-tree root-zone mapping, and Year-1 and Year-5 physical soil and canopy verification.

  • Five indices: Soil Health, Canopy, Water Dynamics, Biodiversity, and Restoration
  • Explicit physical falsifiers so every soil prescription can be tested in the dirt
  • Plain-text Heartwood Markdown paired with SHA-256 verified JSON and GeoJSON
200-Yr Vault Architecture Falsifiability & Proof
Sovereign Engineering

Behind the Veil: Open Engines, AI Verification & CLI

Nothing in Open Arbor is a black box. Developers, urban foresters, researchers, and AI system builders can open the hood below to inspect the live Logical English Orchestration receipt, Model Context Protocol server, and zero-dependency command-line tools.

Technical Substrate Inspect Live LEO-RCA Oracle Anchors, JSON-RPC 2.0 MCP Server & Local CLI
1. Live LEO-RCA Profile 01 Receipt (leoRcaEngine.js)

Synchronized to your current Living Tree Lens sliders. Every prose claim is audited against inline [[oracle:key=value]] anchors and a 3-fixture negative sabotage gate.

STATUS: OA-RCA-v2:ATX-QV-101 | drafts complete: 1/1 | unverified citations: 0 
[[oracle:rca.structural.dbh_in=30]]
[[oracle:rca.biomechanics.t_over_r=0.38]]
[[oracle:root_zone.crz_ft=30]]
[[oracle:root_zone.srz_ft=10.53]]
[[oracle:rca.valuation.holobiont_200yr_usd=218609]]
[[oracle:rca.triage.stage1_usd=2261]]
2. Zero-Dependency CLI & MCP Server

Run deterministic RCA compilations, statutory audits, or the JSON-RPC 2.0 Model Context Protocol server locally in Node.js with zero cloud keys. 

# Verify deterministic parity & LEO-RCA sabotage gates
npm test

# Compile a 10-section RCA evidentiary dossier from CLI
npx openarbor-rca --case austin-live-oak

# Start stdio Model Context Protocol server for Claude / Cursor / Hermes
npx openarbor-mcp
41-Tool Forestry Workbench MCP Agent Playground RCA-Spec v2.0 Reference 8-City Ordinance Validator Executable Proof & Falsifiability
Word-of-Mouth Field Handoff · Zero Account Required

Send This Tree to Your Arborist

Share a calm, pre-computed field baseline with your preferred arborist or property steward. Every figure opens directly in the Field Studio with zero login.

No data is uploaded to any server; the tree state lives inside the link hash.
Open Full Studio