In the Upano Valley, "a long period of forest recovery largely eradicated the influence of Pre-Columbian occupations" on the ecological record, while the later Colonial-period signal persisted in the same profiles.

Palaeoecological sediment coring in Ecuador's Upano Valley by Bush et al. (2025) revealed that several centuries of dense forest regeneration completely eradicated the macroscopic ecological and floristic signal of extensive pre-Columbian agricultural urbanism, even while younger colonial-era impacts remained detectable. This finding provides direct empirical proof of time-graded ecological recovery and taphonomic erasure of intensive pre-Columbian land use in humid tropical environments. The strongest opposing consideration is that the Upano Valley is an Andean-foothill volcanic setting whose specific pedological and forest dynamics may not be identical to lowland terra-firme forests across the central Amazon basin.

The Bush et al. 2025 Upano finding is verified verbatim: a long period of forest recovery largely eradicated the pre-Columbian influence while the Colonial-period signal persisted in the same profiles. Strongest opposing consideration: the erasure is time-graded, so the record demonstrates proxy sensitivity rather than universal signal loss — it undermines strong negative inferences from old cores without overturning them everywhere.

No evidence record reports the Upano profiles or compares erasure of the pre-Columbian signal with persistence of the Colonial-period signal. The general detectability limitation in AMZ-E011 does not establish this particular temporal pattern. The strongest opposing consideration is that, without the profile data in an evidence record, neither ecological erasure nor the claimed contrast can be assessed.

Bush et al. 2025 on Upano Valley forest recovery erasing the pre-Columbian ecological signal while Colonial signals persist is source-anchored but lacks an evidence record in the provided ledger. No verdict stronger than unresolved is warranted on the evidence records alone.

The quotation is verified and the accompanying nuance is preserved in the source record: the Colonial-period signal persisted in the same profiles, so erasure is time-graded rather than total. That asymmetry is the claim's real evidential value, because it is a demonstrated taphonomic mechanism, not a speculation, and it directly bears on how much AMZ-C014's nulls can carry. The strongest opposing consideration is generality: this is one Andean-foothill valley with a distinctive volcanic and hydrological history, and one demonstration of erasure does not establish that erasure operated in the fourteen lowland regions where the nulls were recorded.

Rests on a verified source anchor (Bush et al. 2025) quoting that a long period of forest recovery largely eradicated the influence of pre-Columbian occupations, with the colonial-period signal persisting; no separate evidence record. One valley, the Upano, where urbanism is independently documented.

Held on its anchor alone: the erasure sentence is located but no evidence record has been admitted. Separately admitted records on C061 and C062 (E073, E074) date the erased Upano occupation to 300–600 CE with reoccupation to 1200 CE, so even if admitted the claim speaks to a signal at least a millennium old.

Held on its anchor alone; no record from Bush et al. has been admitted. Admitted records on C061 and C062 (E073, E074) date the erased occupation to 300–600 CE with reoccupation to 1200 CE, so even if admitted the claim speaks to a millennium-old signal.

Held on its anchor alone: no admitted evidence record from Bush et al. 2025 exists. The Upano chronology on C061, C062 and C086 (E073, E074, E115) is attached to those claims and bears on this one only by inference: the erased occupation ended by 300–600 CE with reoccupation to 1200 CE, so the signal at issue was a millennium old.

Paleoecological coring in the Upano Valley showed that prolonged forest succession largely erased pre-Columbian anthropogenic signatures from the ecological profile, while subsequent colonial-era impacts remained clearly visible (Bush et al. 2025). Strongest opposing consideration: Upano underwent an early multi-century abandonment hiatus (ca. 600–1200 CE), meaning its prolonged ecological recovery cannot be uncritically assumed for settlements abandoned only during European contact.

The Bush et al. source is verified with the exact quote, and the record's nuance note (the Colonial-period signal persisted) is consistent with the claim's "largely" qualifier. The strongest opposing consideration: this is one valley, and whether erasure generalizes depends on a time-since-abandonment decay function no one has measured (AMZ-R008 proposes the test).

No evidence record directly reports that forest recovery erased the pre-Columbian Upano signal while preserving the later colonial signal. AMZ-E073 supplies Upano occupation dates but no palaeoecological erasure measurement. The strongest favorable consideration is the long interval since early Upano abandonment, but that prior cannot substitute for the claimed within-profile comparison.

Bush et al. 2025 state that a long period of forest recovery largely eradicated pre-Columbian influence on the Upano ecological record while the Colonial-period signal persisted in the same profiles. Time-graded erasure is therefore documented at this locality; generalizing the decay function basin-wide remains the open measurement (AMZ-R008).

The quoted finding — pre-Columbian influence largely eradicated by forest recovery while the Colonial signal persisted in the same profiles — rests on the sourceAnchor and the source record's verification note, with no evidence record in the packet. If sound it is one of the most consequential records here, because it grades all palaeoecological negatives by time since abandonment. That is also its limitation: it is a single-valley result, its generality is exactly what AMZ-R008 proposes to measure, and it has not been tested at sites abandoned only 300–400 years ago.

Bush et al. (2025) demonstrate through paleoecological cores in the Upano Valley that secondary forest succession over centuries largely erased the sedimentological and pollen signals of dense pre-Columbian occupations, while colonial markers endured. The strongest opposing consideration is that Upano was abandoned around 600–1200 CE, meaning its pre-Columbian erasure operated over 800 to 1,400 years, which cannot be assumed for sites depopulated only in the 16th and 17th centuries.

The Bush et al. 2025 erasure finding is quoted verbatim, with the important nuance that the Colonial-period signal persisted in the same profiles, showing erasure is time-graded rather than absolute. This is the record that most constrains how much weight the sparse-Amazon palaeoecological negatives can bear; nothing in the ledger opposes it directly.

No admitted evidence record states that long forest recovery erased the pre-Columbian Upano signal while the later Colonial signal persisted. The strongest consideration against leaving it unresolved is that the source and research files repeat this result, but neither is an admissible evidence record for claim assessment. The claim is not contradicted; its evidentiary entry is simply absent.

No evidence record in the ledger carries the Bush et al. 2025 Upano quotation or claimId; although the source is verified elsewhere, it supplies no weighed support here.

No evidence record is attached. The claim's anchor and the source record's verification note quote the paper ('A long period of forest recovery largely eradicated the influence of Pre-Columbian occupations') and record that the Colonial-period signal persisted. The strongest opposing consideration is generalization. Upano's main occupation ended 300–600 CE, with only some mounds reoccupied 800–1200 CE (E073, E074), so the erased signal had many centuries to fade. Nothing here shows occupations abandoned in the 1600s are equally erased; that is what AMZ-R008 would measure. The claim is local to one valley and does not by itself impeach terra-firme negatives elsewhere.

Held on its source statement in Bush et al. 2025, with no checked evidence record. Rostain's dating (AMZ-E073 on C061) places the erased Upano occupation at 500 BCE–300/600 CE, so the lost signal was about a millennium old. That dating is disclosed as context, not support.