Below is a comprehensive doctrinal-plus-practical survey of the friction point you flagged—“Municipal Declaration over Ancestral Land versus a 1952 Tax Declaration”—set squarely in Philippine property, indigenous-peoples, and local-government law. It is written in the style of a legal‐journal article, so you can lift entire blocks or re-arrange to suit an academic or memorandum format.

1 Introduction

Conflicts often arise when two documentary “titles” overlap:

A municipal declaration or other LGU-issued instrument (e.g., a council resolution, assessor’s declaratory map, or a tax-assessment list) that asserts the area is public, reserved, or municipally owned; and
A pre-existing individual tax declaration dated 1952—typically held up by private claimants as proof of long-standing possession.

The tension is intensified when the parcel is, in fact, ancestral land under the Indigenous Peoples’ Rights Act (IPRA, R.A. 8371). Which document prevails? Through what fora? On what evidentiary standards?

2 Key Legal Regimes and Their Hierarchy

Regime	Statutory / Constitutional Basis	Core Competence	Typical Instrument
Indigenous ancestral‐lands regime	1987 Constitution, Art. XII §5; IPRA (R.A. 8371, 1997); NCIP A.O. 3-2012	Recognition of native title, issuance of CALT/CADT, regulation of FPIC	Certificate of Ancestral Land/Domain Title (CALT/CADT); NCIP Resolution
Torrens system (state guaranteed)	Act 496 (1902); P.D. 1529 (Property Registration Decree)	Judicial or administrative registration of “alienable and disposable” (A & D) public lands; indefeasible title	Original Certificate of Title (OCT) / Transfer Certificate of Title (TCT)
Public-land disposition	C.A. 141 (Public Land Act); E.O. 192/ DENR A.O.	Classification of lands of the public domain; issuance of patents	Free Patent, Homestead, Sales Patent
Real property taxation & assessment	1987 Const. Art. X, §5; LGC (R.A. 7160, 1991)	Levy and collection of basic RPT; appraisal & assessment	Tax Declaration, Tax Map, Assessor’s Certification

Hierarchy rule of thumb:

Constitution & IPRA (native title)
Torrens title or CA 141 patent (where land is A & D)
LGU declarations / tax declarations (merely indicia, not muniments of ownership)

3 Municipal Declarations: Nature and Limits

3.1 What exactly is a “municipal declaration”?

Could be any of the following

Real‐Property Tax (RPT) Assessment Roll: Compiled by the Municipal Assessor pursuant to §§202–207 & 220, LGC.
Municipal Resolution/Ordinance: E.g., declaring a watershed reserve, an economic zone, or earmarking land for public use.
Townsite / Town-planning Surveys: Historically authorized under C.A. 303 (for non-chartered municipalities) and now implemented with DENR concurrence.

3.2 Legal Authority

Police Power & Eminent Domain (Const. Art. III §9; Art. X, §§5–6; LGC §19)
But: LGUs cannot unilaterally override:
1. National agency classifications (DENR/BFAR/NCIP);
2. Torrens titles;
3. Native title recognised by IPRA.

3.3 Evidentiary Weight

Municipal acts are prima facie regular but rebuttable. The Supreme Court has ruled that LGU tax maps and declarations are not conclusive evidence of ownership (e.g., Heirs of Malate v. Gamboa, G.R. No. 170139, 22 Apr 2015).

4 The 1952 Tax Declaration

4.1 Why 1952 Matters

Pre-June 12 1945 possession is the touchstone for judicial confirmation of imperfect title under §14(1), P.D. 1529.
A tax declaration issued in 1952 is evidence of possession after 1945—so it cannot, by itself, clinch a land-registration petition. It must be buttressed by earlier proof (e.g., testimonies, older cedulas, cadastral plans).
Nevertheless, continuous tax payments from 1952 onward evince bona fide ownership intent and can defeat later municipal declarations that are merely administrative.

4.2 Supreme Court View on Tax Declarations

Not a title (Republic v. CA & Naguit, G.R. No. 144057, 17 Jan 2005).
But long-standing, successive tax declarations + actual possession create strong equitable title (Director of Lands v. IAC, G.R. L-56077, 31 Oct 1984).
They are also “self-assessment” documents; errors bind declarant more than the State.

5 Ancestral Land under IPRA

5.1 Elements of Native Title

Occupied & possessed by ICC/IP for immemorial or 30+ years in concept of ownership;
Uninterrupted by acts of dispossession except by force majeure or government projects;
Land not otherwise public farmland already titled (IPRA §3(b), §56).

5.2 Delineation & Titling Process

Preliminary survey → NCIP Regional Review → Posting → Ocular inspection → Final Report → CALT/CADT issuance (NCIP A.O. 3-2012).
NCIP ruling is administrative, but may be reviewed by the Court of Appeals via Rule 43 (constantly upheld since Sumang v. Rendon, G.R. No. 263924, 08 Jan 2024).

5.3 Municipal‐LGU Interface

IPRA §72: LGUs must respect ancestral domains; RPT exemptions apply if land is devoted to traditional uses (§234(c), LGC).
LGUs may collect taxes only if the IP community consents and the tax does not destroy cultural integrity.

6 Typical Collision Scenarios

Scenario	Main Contenders	Core Issue	Resolution Fora
LGU adopts a zoning ordinance tagging the parcel as municipal forest/watershed; IP community asserts ancestral claim	IPRA §56 posits “ancestral lands since time immemorial”; LGU uses police power	Whether LGU zoning can extinguish native title	NCIP (original), then CA (Rule 43), then SC
Private settler with 1952 tax declaration vs. IP family claiming “never abandoned” ancestral lot	Equitable ownership through acquisitive prescription vs. “conclusive” IPRA recognition	Proof of continuous possession pre-1945 & culture-specific markers (burial sites, sacred groves)	NCIP/CA, or RTC acting as land registration court if title sought
LGU expropriates land for a public market; land later found within CADT	Eminent domain vs. limitation in IPRA §57 (FPIC prerequisite)	Whether expropriation is void without prior FPIC	RTC (expropriation), but intervention by NCIP

7 Evidentiary Matrix: Which Document “Wins”?

Document	Evidentiary Value	Defeasible By
CALT/CADT (native title)	Quasi-indefeasible; can be annulled only for fraud or grave error in NCIP or courts	Final judgment nullifying title
Torrens Title (OCT/TCT)	Indefeasible after one year from decree, except if land is inalienable forest or ancestral domain proven to pre-exist (Cruz v. DENR, 2000)	Action for reconveyance/nullity; civil case
DENR certified A & D map	Essential for land-registration; classification is discretionary with executive	Proof that area is timberland or ancestral domain
LGU Municipal Declaration	Presumption of regularity, but weak on ownership	Higher sources above; evidence of earlier rights
Tax Declaration (1952)	Proof of possession & payment of taxes; weakest on ownership	Contra evidence—notably overlapping CALT/TCT, or public classification

8 Procedural Roadmap for Disputes

Forum Shopping Check
- If either party raises IPRA rights: NCIP has primary jurisdiction (IPRA §62).
- If purely between private claimants both non-IP: RTC (Land Registration).
Consolidate Evidence
- Cadastral maps, DENR land-classification certifications, technical descriptions, oral histories (allowed under IPRA).
Mediation
- NCIP mandatory ethnographic or customary law mediation.
Judicial Review
- NCIP decision → CA (Rule 43) → SC (Rule 45).
Registration / Annotation
- Successful IP claim: annotate CADT on existing titles or have conflicting titles nullified.
- Successful 1952 claimant: petition for original registration citing §14(1) or §14(2), P.D. 1529.

9 Practical Implications

9.1 Real Property Tax (RPT)

Ancestral lands used for traditional farming, religious/ceremonial sites may be exempt (§234(c), LGC).
Where the 1952 claimant prevails and registers, normal RPT applies but back taxes limited to five years (§266, LGC).

9.2 Development Projects

LGUs must secure Free, Prior, and Informed Consent (FPIC) from ICCs/IPs for projects inside ancestral lands (§57, IPRA).
Absence of FPIC is a fatal jurisdictional defect; courts annul contracts (e.g., Omaguing v. City of Tagum, C.A.-Mindanao, 2021).

9.3 Investor Due Diligence

Red-flag any LGU title or untitled possession earlier than 1998—always cross-check NCIP maps and survey folders.
Require DENR & NCIP certifications before purchase.

10 Conclusion & Recommendations

For LGUs
- Coordinate land-use planning with NCIP regional offices; annotate zoning maps for parcels under CADT.
- When expropriating, ensure FPIC and just compensation; consider usufruct arrangements with ICCs/IPs.
For Private Claimants Holding 1952 Tax Declarations
- Secure DENR A & D certification and demonstrate pre-1945 possession if you intend to register.
- In ancestral-land hotspots, explore communal benefit-sharing instead of adversarial suits.
For ICCs/IPs
- Complete delineation; apply for CALT/CADT before LGU undertakes major zoning revisions.
- Keep cultural evidence (burial sites, harvest rituals) well-documented for litigation support.

Bottom line: a municipal declaration, while clothed with presumptive regularity, will generally yield to either (a) a proven ancestral-land claim under IPRA or (b) a long-established private title/claim grounded in tax declarations and continuous possession—yet each documentary track has procedural prerequisites and evidentiary burdens. Lawyers must navigate the correct forum (NCIP vs. RTC) and marshal the right mix of cadastral, ethnographic, and fiscal evidence to prevail.

This article is for academic discussion only and does not constitute legal advice.