Light responses of Carex planostachys from various microsites in a Juniperus community |
| |
| Authors: | ER Wayne OW Van Auken |
| |
| Institution: | 1. Department of Biology, Trinity University, San Antonio, TX 78212-7200, United States;2. Department of Biology, University of Texas at San Antonio, San Antonio, TX 78249, United States;1. Department of Obstetrics and Gynecology, Ospedale San Gionvanni di Dio, University of Cagliari, Cagliari, Italy;2. Department of Radiology, Azienda Ospedaliero Universitaria di Cagliari – Polo di Monserrato, Cagliari, Italy;3. Department of Obstetrics and Gynecology, Clínica Universidad de Navarra, University of Navarra, Spain;1. Department of Electrical, Systems and Automatic Engineering, University of Leon, Spain;2. Johann Bernoulli Institute for Mathematics and Computer Science, University of Groningen, The Netherlands;3. Department of Mechanical, Computing and Aerospace Engineering, University of Leon, Spain;1. College of Mathematical Science, Tianjin Normal University, No. 393 Binshuixi Road, Xiqing District, Tianjin 300387, PR China;2. College of Urban and Environmental Science, Tianjin Normal University, Tianjin 300387, PR China;3. Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, No. 393 Binshuixi Road, Xiqing District, Tianjin 300387, PR China;4. Department of Hydrology and Water Resources, The University of Arizona, John Harshbarger Building, 1133 E. North Campus Drive, Tucson, AZ 85721, USA;1. Escola de Agronomia, Universidade Federal de Goiás, Goiânia, GO, 74690-900, Brazil;2. Instituto de Química, Universidade Federal de Goiás, Goiânia, GO, 74690-900, Brazil;3. Instituto de Matemática e Estatística, Universidade Federal de Goiás, Goiânia, GO, 74690-900, Brazil;1. Department of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Iran;2. Department of Mechanical Engineering, Sari Branch, Islamic Azad University, Sari, Iran |
| |
| Abstract: | Juniperus communities are found on over 50 × 106 ha in arid and semiarid habitats in southwestern North America. The drought tolerant sedge Carex planostachys occurs below the canopy in some of these communities. Cover and biomass of C. planostachys are high below the canopy and low in associated gaps. The purposes of this study were to investigate the temporal and spatial physiologic response of C. planostachys to abiotic changes, and determine it's light response characteristics from four contiguous microsites. Net photosynthesis was highest in spring when temperature was cooler and soil water higher, but low carbon uptake continued during summer drought. In addition, C. planostachys demonstrates a capacity to recover from extreme drought, despite water potential measured below ?9.0 MPa. Based on physiological light response curves and gas-exchange measurements, C. planostachys appears tolerant of shaded and full sun habitats. Light levels below the canopy were reduced compared to the gaps, but light saturation of C. planostachys did not change and net CO2 uptake was only reduced slightly. Carbon uptake was coupled to light levels and not soil moisture. Observed differences in physiological attributes and variation in C. planostachys cover and biomass correspond to the presence or absence of the canopy. Low light compensation points, coupled with reduced respiratory demand, maximize photosynthetic gain in low light microsites. C. planostachys appears to acclimate across a range of light regimes, suggesting photosynthetic plasticity, allowing growth and survival in diverse light microhabitats. C. planostachys, tolerant of drought, appears anisohydric and demonstrates a capacity to acclimate to sun and shaded habitats, which could allow it to occur across a wider range of arid areas. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
