Helicopter Liming to Help Restore Acidified Forest Soil Productivity 
Bibliographic record
Abstract
Decades of acid deposition across northeastern North America has caused excess leaching of soil base cations (Ca2+, Mg2+, K+) and increases in bioavailable aluminum (Al3+) that, in combination, have resulted in widespread decreases in potential forest productivity. Despite major reductions in SO2 and NOx emissions since the 1990s, forest soils across the region have shown few signs of recovery from acid deposition impacts and it could take decades or centuries for natural recovery to occur. As a result, affected forests are stressed, less productive, and more prone to climate change-induced damage. Helicopter liming of upland forests may be an effective way to jump-start the soil recovery process. Here we report on early results (one-year) from a helicopter liming trial in Nova Scotia, Canada where 10 tonnes/ha of dolomitic limestone was applied to approximately 8 ha of mature red spruce (Picea rubens) and mature tolerant hardwood (Acer spp. and Betula spp.) forest. Data are presented on (i) the effectiveness of helicopter liming in forests; (ii) the initial chemical response of forest floor organic and mineral soil horizons; and (iii) the initial chemical response of red spruce foliage, maple foliage, and ground vegetation. Preliminary results showed that despite non-uniform lime distribution, there were significant increases (P < 0.05) in Ca2+, Mg2+, pH, and base saturation (BS), and significant decreases in total acidity in forest floor organic horizons in both the mature red spruce and tolerant hardwood stands; however, there were no significant changes in Al3+. The initial chemical response in sugar maple and red spruce foliage showed significant increases in the Ca/Al molar ratio . The initial response in ground vegetation (Schreber’s moss; Pleurozium schreberi and wood fern; Dryopteris intermedia) showed significant increases in Ca2+ and decreases in K+ for both species; however, Schreber’s moss also showed significant increases in Mg2+ and Al3+ while wood fern did not. These early chemical results are promising and further support the use of helicopter liming as an effective tool to combat lingering effects from acid deposition in acidified forests.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".