SOIL CARBON, NITROGEN, AND PHOSPHORUS STOCKS AND DYNAMICS UNDER DISTURBED BLACK SPRUCE FORESTS
Bibliographic record
Abstract
In the North American boreal forest, black spruce (Picea mariana) forests have historically regenerated after the passage of large-scale wildfires. Over the past 30 years, tree harvesting has replaced wildfire as the predominant agent of disturbance in black spruce–feathermoss communities in the Lac St. Jean–Chibougamau region of Quebec, Canada. This study addressed how natural and anthropogenic disturbances altered soil and fine root carbon (C), nitrogen (N), and phosphorus (P) stocks and dynamics under four disturbance types in central Quebec including: (1) recently burned sites, (2) sites recently harvested using a practice called “cutting with protection of tree regeneration and soils” (CPRS), (3) sites that were burned 75–85 yr ago, and (4) sites that were horse-logged 55 yr ago. Soil N contents in the surface organic layer of the recently burned sites (91 g/m2) were significantly lower than under the old burn sites (146 g/m2). Using equivalent soil masses, total N stores in the mineral soils under the recently harvested stands (76 g/m2) were significantly lower than N stores under the old burn sites (114 g/m2). In field incubations from June to October 1997, net N mineralization rates in the organic horizons ranged from 3.3 kg/ha (recent burn) to 17.1 kg/ha (old harvest). The largest pools of labile inorganic-P (Bray 2 extractable) were in the organic horizons of the old harvest and old burn sites (59.1 and 55.3 mg/kg, respectively), and these pools increased up to 24% from the beginning to the end of the growing season. Pools of dissolved organic nitrogen in surface organic horizons in all of the disturbance types were highest just after snowmelt and declined steadily through the growing season. The older disturbance types had higher N stores in fine roots compared to the recently disturbed sites, and fine root length in the old harvest sites (1623 m/m2) was higher than in the stands burned 75–85 yr ago (917 m/m2).
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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 teacher head, 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".