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A comparative kinetic analysis of nitrate and ammonium influx in two early‐successional tree species of temperate and boreal forest ecosystems

2000· article· en· W2062106160 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenuePlant Cell & Environment · 2000
Typearticle
Languageen
FieldAgricultural and Biological Sciences
TopicPlant nutrient uptake and metabolism
Canadian institutionsWestern UniversityUniversity of British Columbia
Fundersnot available
KeywordsPinus contortaTemperate climateTaigaNitrateAmmoniumTemperate forestBotanyEcosystemBorealChemistrySalicaceaeEcologyWoody plantBiology

Abstract

fetched live from OpenAlex

ABSTRACT Root NO 3 − and NH 4 + influx systems of two early‐successional species of temperate (trembling aspen: Populus tremuloides Michx.) and boreal (lodgepole pine: Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forest ecosystems were characterized. NO 3 − and NH 4 + influxes were biphasic, consisting of saturable high‐affinity (HATS) and constitutive non‐saturable low‐affinity transport systems (LATS) that were evident at low and relatively high N concentrations, respectively. NO 3 − influx via HATS was inducible (IHATS); nitrate pre‐treatment resulted in 8–10‐fold increases in the V max for influx in both species. By contrast, HATS for NH 4 + were entirely constitutive. In both species, V max values for NH 4 + influx were higher than those for NO 3 − uptake; the differences were larger in pine (6‐fold) than aspen (1·8‐fold). In aspen, the K m for NH 4 + influx by HATS was approximately 3‐fold higher than for IHATS NO 3 − influx, while in pine the K m for IHATS NO 3 − influx was approximately 3‐fold higher than for NH 4 + influx. The aspen IHATS for NO 3 − influx appeared to be more efficient than that of pine ( V max values for aspen being approximately 10‐fold higher and K m values being approximately 13‐fold lower than for pine). By contrast, only small differences in values for the NH 4 + HATS were evident between the two species. The kinetic parameters observed here probably result from adaptations to the N availabilities in their respective natural habitats; these may contribute to the distribution and niche separation of these 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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.293
Threshold uncertainty score0.220

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.015
GPT teacher head0.198
Teacher spread0.183 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it