THE INTERACTIVE EFFECTS OF MICROTOPOGRAPHY AND HYDROLOGY ON GROUND LAYER VEGETATION AND SOIL GAS FLUX RESPONSES TO A SIMULATED EMERALD ASH BORER INFESTATION IN BLACK ASH WETLANDS
Bibliographic record
Abstract
Black ash (Fraxinus nigra Marshall) wetlands are at risk of significant ecological and functional changes due to the invasive emerald ash borer (EAB) (Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)), which kills trees in the Fraxinus (ash) genus. Simulated EAB infestations consisting of girdle treatments and ash cut treatments have been implemented in black ash wetlands to study the impacts of black ash canopy dieoff in these systems. Initial findings include ground layer vegetation shifts and impacts to carbon dioxide (CO2) and methane (CH4) release from soils, but these factors and their interactions with microtopography in these systems are not well understood. The objectives of this study were to explore how vegetation and greenhouse gas fluxes (GHGs) are currently responding to simulated EAB treatments in the Ottawa National Forest in the Great Lakes Region of North America six years after initial treatment implementation, and to determine how microtopography affects them as well. Tree seedling counts and diversity were not found to be affected by treatments alone. Microtopography, however, had a larger impact and showed more seedlings and a higher diversity of seedlings growing on hummocks. Seedlings over one year of age were also found in greater numbers and with more diversity on top of hummocks. Herbaceous species have continued their trend of increased cover in treated sites, with higher cover of obligate wetland species and graminoids in treated sites as well. Increased herbaceous cover was found on top of hummocks rather than in hollows. These findings suggest that herbaceous cover is influenced by both treatments and microtopography, while tree regeneration is more influenced by microtopography. The implications of the lack of response between treatments for seedlings is that the increase in water levels at our wetland sites may be buffered by microtopography and our sites could continue to stay forested following an EAB infestation. CO2 and CH4 fluxes showed different responses to treatment and microtopography. CO2 flux was highest in control sites and on top of hummocks, while CH4 was not found to be different between treatments or microtopography. The postulated reasons for these findings are depth to water table and root respiration. For CO2, the lower water levels allowed for more soil to be aerated and decomposed, and there is more root respiration in control sites because of a higher volume of living trees. For CH4, the low water levels created an environment where little CH4 was produced at all. When
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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 | 0.000 | 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 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".