Aboveground biomass of understorey vegetation has a negligible or negative association with overstorey tree species diversity in natural forests
Bibliographic record
Abstract
Abstract Aim The positive relationships between tree species diversity, aboveground biomass and productivity of overstorey tree layers have been widely reported in tropical, temperate and boreal forest ecosystems. However, no consensus has been arrived at on the association between overstorey tree species diversity and the functions of understorey vegetation, such as the biomass of understorey tree, shrub, herb and bryophyte layers, despite their critical contributions to the diversity and functions of natural forests. Location Canadian forest (42°37′ to 68°14′ N; 53°25′ to 134°46′ W; 4 to 2170 m elevation). Methods We employed Canada's National Forest Inventory dataset to evaluate the influences of overstorey tree species diversity on the aboveground biomass of each forest stratum by accounting for the effects of climate, site condition and stand age. Results We found that aboveground biomass of overstorey trees and total aboveground biomass were positively associated with overstorey tree species richness; however, the aboveground biomass of understorey trees, shrubs, herbs and bryophytes were not associated or were negatively associated with overstorey tree species richness, evenness and life‐history trait variations. Main conclusions Our results show positive associations between aboveground biomass of the overstorey tree layer and overstorey tree species diversity over a wide range of climate, local site conditions and stand ages in natural forests. However, contrary to previous findings that more tree species result in higher levels of multiple ecosystem functions, including understorey plant functions, our results demonstrate that the aboveground biomass of understorey vegetation has either a negligible or negative association with overstorey tree species diversity. The negative associations between overstorey tree species diversity and understorey biomass possibly resulted from greater resource filtering by overstorey trees in ecosystems with more diverse overstorey tree species.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".