Patterns of canopy interception and throughfall along a topographic sequence for black spruce dominated forest ecosystems in northwestern Ontario
Bibliographic record
Abstract
A 3-year (19931995) study was conducted to describe both the spatial (within- and between-site) and temporal (monthly) patterns associated with canopy interception, throughfall, and net forest water along a black spruce (Picea mariana (Mill.) BSP) topo-sequence situated in northwestern Ontario. This site array included (1) an upland, well-drained, mineral soil site; (2) a poorly drained, midslope, wet mineral site; and (3) a treed wetland on organic (peat) soil. Bulk precipitation (BP) and throughfall (TF) were collected, on an event basis (63 events, over 4800 samples analyzed), using standard collecting devices and analyzed for total Kjeldahl nitrogen (TKN), ammonium (NH4+), nitrate (NO3), total phosphorus (TP), potassium (K), calcium (Ca), and magnesium (Mg). Comparison of BP and TF data suggested that an enrichment of K (190%), Mg (115%), and Ca (70%) occurred during canopy interactions. On the other hand, inorganic nitrogen (NH4+: 73%; NO3: 47%), and to a lesser extent TP (35%), rates declined. TKN, however, remained the same, suggesting that inorganic N reductions were offset by organic N inputs. Downward shifts in pH were also detected for TF (4.454.48), as compared with the pH of BP (4.524.80). Although all study sites received similar rainfall amounts, the more productive sites (i.e., carrying greater foliar mass, higher leaf area index) had lower TF volumes (i.e., higher interception rates) but higher macronutrient returns to the forest floor. This increase in macronutrient deposition was directly related to substantial increases in nutrient concentrations, which, in turn, suggested a greater degree of canopy interaction and (or) leaching on these sites. Throughfall pH, however, was not significantly different across the three study sites. With respect to temporal patterns, the major cations (K+, Ca2+, Mg2+) demonstrated an increasing trend in concentration levels in TF as the season progressed to a maximum in October. TKN and TP concentrations, on the other hand, maintained relatively stable levels throughout the summer, peaking in September, but dropping substantially in October as metabolic processes slowed and the supply of these nutrients to the foliage was reduced. Even with the increase in base cation concentration, throughfall pH shifted downward to 4.3 or below by late fall.
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 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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 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 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".