Effects of flooding on photosynthesis and root respiration in Salt cedar (tamarix ramosissima), an invasive riparian shrub
Bibliographic record
Abstract
The introduced shrub Tamarix ramosissima Lebed. invades riparian zones, but loses competitiveness under flooding. This was tested in Tamarix ramosissima by examining responses to flooding by soil type in a greenhouse setting. A field study examined responses of Tamarix ramosissima and other species to natural flooding. Leaf level photosynthesis rates, stomatal conductance, transpiration, and root alcohol dehydrogenase (ADH) activity were measured weekly to assess oxygen stress. In the field, stomatal conductance, leaf water potential, transpiration, canopy cover, and δ13C were measured as responses to soil water potential, soil moisture, Julian date, relative humidity, and water depth. In the greenhouse study, flooding affected Tamarix ramosissima initially. Photosynthesis rates within flooded plants ranged from 7.5 to 14 μmol CO2 m-2 s-1 during the first two weeks, but increased to 26.9 to 27 μmol CO2 m-2 s-1 by the fourth week. As flooding progressed, photosynthesis rates increased as plants became acclimated. Lower photosynthesis rates at the onset of flooding could account for the susceptibility of Tamarix ramosissima to flooding. Soil type had no effect on photosynthesis rates or on root ADH activity. Root ADH activity was higher in flooded plants compared to drained plants, indicating oxygen stress in flooded plants. The ability of Tamarix ramosissima to acclimate to flooding within four weeks indicated metabolic acclimation. In the field study, Tamarix ramosissima had lower stomatal conductance and leaf water potential compared to Populus deltoides Bartr. and Phragmites australis (Cav.) Trin. ex Steud at -1.4 MPa and 1.5 mol H2O m-2 s-1. Lower leaf water potential and stomatal conductance in the field can also account for loss of competitiveness of Tamarix ramosissima under flooding. Typha angustifolia L. had the highest canopy cover compared to Tamarix ramosissima, Melilotus officinalis (L.) Lam., Baccharis salicina Torr. & A. Gray, and Saccharum ravennae (L.) L. Differences in canopy cover indicated Typha angustifolia was more tolerant of flooding compared to Tamarix ramosissima. Nonetheless, T. ramosissima is more flooding tolerant than previously realized. Differences in physiological responses for Tamarix ramosissima could become important for ecological or management concerns with this 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 | 0.000 |
| 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) | 0.000 | 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".