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Arid and semi-arid ecosystems of the southwestern US are undergoing changes in vegetation composition and are predicted to experience shifts in climate. To understand implications of these current and predicted changes, we conducted a precipitation manipulation experiment on the Santa Rita Experimental Range in southeastern Arizona. The objectives of our study were to determine how soil surface and seasonal timing of rainfall events mediate the dynamics of leaf-level photosynthesis and plant water status of a native and non-native grass species in response to precipitation pulse events. We followed a simulated precipitation event (pulse) that occurred prior to the onset of the North American monsoon (in June) and...
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These plant and soil data were collected by Timothy M. Wertin and Sasha C. Reed in the spring, summer, and fall of 2011 at a climate manipulation experiment site near Moab, UT (38.521411, -109.470567). These data were collected to assess how warming affects leaf photosynthesis, soil CO 2 efflux, and soil chemistry in plots of ambient and warming treatments.
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Larrea tridentata is a xerophytic evergreen shrub, dominant in the arid regions of the southwestern United States. We examined relationships between gasexchange characteristics, plant and soil water relations, and growth responses of large versus small shrubs of L. tridentata over the course of a summer growing season in the Chihuahuan Desert of southern New Mexico, USA. The soil wetting front did not reach 0.6 m, and soils at depths of 0.6 and 0.9 m remained dry throughout the summer, suggesting that L. tridentata extracts water largely from soil near the surface. Surface soil layers (max) occurred in early summer (21.3 � mol m-2 s-1), when pre-dawn xylem water potential (XWP) reached ca. -1 MPa. Although both...
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These data were compiled to assess physiological responses of plants to short-term changes in streamflow, both increased and decreased. Objective(s) of our study were to determine the degree to which plants with different habitat preferences and functional strategies responded to short-term increases or decreases in the elevation of the water table. These data represent streamflow rates, temperature, and metrics of plant water status. These data were collected in Glen Canyon National Recreation Area from March 13-27, 2021, and collected by the U.S. Geological Survey-Grand Canyon Monitoring and Research Center. Streamflow data were obtained from the Lees Ferry gage station, and temperature data were obtained from...
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The following files contain source data for use of the Community Land Model 4.0 at two study sites in Volcanoes National Park, Hawai'i. Included are: Biometric data: 1) Growth increment data for Thurston and Olaa, based on dbh surveys done in four 10 m by 10 m plots at over a 12 year time period at Thurston and at six plots overs a 12 year period at Olaa, 2) Field measured leaf area index data. Measurements were made using LAI-2000 and LAI-2200 instruments, 3) Litterfall from Thurston and Olaa over a 17-mo period from June 2014 to Sep 2015. Data were sorted by species/litter type. Data are weights., 4) Field measured soil respiration data scaled to annual values and compared with tower-based measurements of ecosystem...
? This research tested the hypothesis that experimental infrared warming will reduce photosynthesis for the evergreen shrub Artemisia tridentata and the subalpine, herbaceous Erythronium grandiflorum exposed to an in situ experimental freezing event during the spring snowmelt period. ? Photosynthetic tolerance of freezing was measured for plants growing under infrared (IR) warming at 3050 m in the Rocky Mountains, Colorado, USA. In situ freezing was imposed using cold nitrogen gas (from a pressurized container of liquid nitrogen) passed through a heat exchanger placed on top of stems and leaves. ? Plant water potential, photosynthetic CO2 assimilation, and stomatal conductance to water vapor were higher for both...
Plants of four Great Basin grass species were grown from seed in two greenhouses at low (340 ? l l-1) and high (680 ? l l-1) CO2 concentration. In all four species, high CO2 promoted mean increases in the number of basal stems, leaf area, specific leaf weight and above-ground dry weight. High CO2 resulted in an increase in CO2 assimilation in two C3 grasses but not in a C4 grass, while all three species showed decreases in stomatal conductance. Mean increases of 60% in aboveground dry weight and 80% in water-use-efficiency are consistent with previously reported high CO2 effects on grasses. No consistent differential effects of high CO2 were observed when comparing annual vs perennial species. Global CO2 enrichment...
There is a long-standing controversy as to whether drought limits photosynthetic CO2 assimilation through stomatal closure or by metabolic impairment in C3 plants. Comparing results from different studies is difficult due to interspecific differences in the response of photosynthesis to leaf water potential and/or relative water content (RWC), the most commonly used parameters to assess the severity of drought. Therefore, we have used stomatal conductance (g) as a basis for comparison of metabolic processes in different studies. The logic is that, as there is a strong link between g and photosynthesis (perhaps co-regulation between them), so different relationships between RWC or water potential and photosynthetic...
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These data were compiled to identify potential contributions of drought and inundation tolerance to vegetation composition along the Colorado River. Objective(s) of our study were to quantify physiological and growth responses of different plant species to drought and inundation. These data represent measurements taken on container plants in a greenhouse, and hydrological niche values based on field monitoring data that are published elsewhere. These data were collected in summer of 2022 at the Northern Arizona University Research Greenhouse Complex. These data were collected by Northern Arizona University and U.S. Geological Survey scientists in a greenhouse and laboratory setting. These data can be used to assess...
Categories: Data; Tags: Arizona, Botany, Colorado River, Ecology, Flagstaff, All tags...
The effects of salt stress on growth and development of cheatgrass (Bromus tectorum L.) were investigated in 2 greenhouse studies. The first study assessed developmental and physiological responses of this grass to 4 salinity levels. Salinity stunted growth through reduced leaf initiation and expansion, and reduced photosynthetic rates. Reduction of photosynthetic rates appeared to be primarily due to stomatal limitation. Salinity also reduced carbon isotope discrimination, indicating long-term effects on conductance and carbon gain. Root growth was severely inhibited by high salinity, resulting in a shift in the root to shoot allocation pattern. The second study investigated growth patterns of cheatgrass in relation...
    map background search result map search result map Effects of plant size and water relations on gas exchange and growth of the desert shrub Larrea tridentata Experimental Design Plant and Soil Measurement Data for Achnatherum hymenoides from a warming experiment, Colorado Plateau, 2011 - Data Observed ecological inputs to the Community Land Model at two wet montane study sites, 2004-2016, Volcanoes National Park, Hawai'i Hydric and mesic riparian plant species data for quantifying divergent physiological responses to a Colorado River experimental flow Experimental inundation and drought response data for twelve riparian plants occurring along a local hydrologic gradient in the Colorado River ecosystem Experimental inundation and drought response data for twelve riparian plants occurring along a local hydrologic gradient in the Colorado River ecosystem Observed ecological inputs to the Community Land Model at two wet montane study sites, 2004-2016, Volcanoes National Park, Hawai'i Experimental Design Plant and Soil Measurement Data for Achnatherum hymenoides from a warming experiment, Colorado Plateau, 2011 - Data Effects of plant size and water relations on gas exchange and growth of the desert shrub Larrea tridentata Hydric and mesic riparian plant species data for quantifying divergent physiological responses to a Colorado River experimental flow