Shifting with climate? Evidence for recent changes in tree species distribution at high latitudes
Bibliographic record
Abstract
Warming has been particularly strong at high latitudes in recent decades and bioclimatic models predict northern shifts in optimal conditions for most species. Climate is a strong predictor of site occupancy for trees at broad spatial scales and interacts with other drivers of forest dynamics. Recent changes in distribution and occupancy patterns should therefore provide the best evidence of a tree species' potential to shift in the direction predicted by bioclimatic models. Studies examining recent distribution changes for plants, however, have mostly done so along altitudinal gradients or have used the latitudinal position of juvenile trees relative to adult ones to infer range dynamics. This study provides rare evidence of latitudinal shifts for 11 northern tree species by assessing recent changes in distribution using globally significant inventories from 1970 to 2002. It also compares observed trends with those inferred from the position of juveniles relative to trees in a single survey. Samplings cover 6456 forest plots in temperate and boreal forests up to treeline in eastern North America. The average overall latitudinal shift was 3.07 ± 4.37 km northward although responses were species‐specific. Shifts were detected more for juvenile than for adult trees and significant northward ones were detected more at northern range limits than at the median. All species demonstrated increased frequency of plot occupancy for saplings while occupancy generally decreased for adult trees. Five out of the 11 species examined ( Acer rubrum , Acer saccharum , Betula papyrifera , Fagus grandifolia , and Populus tremuloides ) showed significant distributional shifts consistent with northward migration. Saplings of Abies balsamea , Picea glauca , and Picea mariana , on the other hand, showed southward shifting trends. Natural and human disturbances undoubtedly interact with climate to determine forest dynamics; this study shows whether their combined effect can shift distribution in the direction predicted by bioclimatic models. Only continued monitoring will reveal whether these observations are just transient dynamics or indicative of shifting range in this century. Our study provides a benchmark against which to assess future observations of latitudinal shifts for trees.
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 | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| 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".