Seasonal photosynthetic gas exchange and water-use efficiency in a constitutive CAM plant, the giant saguaro cactus (Carnegiea gigantea)

  title={Seasonal photosynthetic gas exchange and water-use efficiency in a constitutive CAM plant, the giant saguaro cactus (Carnegiea gigantea)},
  author={Dustin R. Bronson and Nathan B English and David L. Dettman and David G. Williams},
Crassulacean acid metabolism (CAM) and the capacity to store large quantities of water are thought to confer high water use efficiency (WUE) and survival of succulent plants in warm desert environments. Yet the highly variable precipitation, temperature and humidity conditions in these environments likely have unique impacts on underlying processes regulating photosynthetic gas exchange and WUE, limiting our ability to predict growth and survival responses of desert CAM plants to climate change… 
Seasonal controls on ecosystem-scale CO2 and energy exchange in a Sonoran Desert characterized by the saguaro cactus (Carnegiea gigantea)
The ecosystem showed large (fivefold) seasonal variation in maximum photosynthesis and ecosystem respiration rate at 10 °C that corresponded to seasonal variationIn precipitation and temperature, and recorded a net loss of 10 g C m−2 year−1, which was likely caused by below normal annual precipitation during the study.
Gas exchange characteristics of giant cacti species varying in stem morphology and life history strategy.
The results add to a growing body of evidence that succulent-stemmed plants function along a similar economic spectrum as leaf-bearing plants such that functional traits including stem RGR, longevity, morphology, and gas exchange are correlated across species with varying life-history strategies.
Contribution of stem CO2 fixation to whole-plant carbon balance in nonsucculent species
Stem net photosynthesis (SNP) is proposed, which includes net CO2 fixation by stems with stomata in the epidermis and net corticularCO2 fixation in suberized stems, and stem recycling photoynthesis (SRP), which defines CO2 ling in su berized stems.
Functional trade-offs in succulent stems predict responses to climate change in columnar cacti.
It is proposed that variation in photosynthetic gas exchange, growth, and response to stress is highly constrained by stem V:S, establishing a mechanistic framework for understanding the sensitivity of columnar cacti to climate change and drought.
Carbon dioxide exchange over multiple temporal scales in an arid shrub ecosystem near La Paz, Baja California Sur, Mexico
Arid environments represent 30% of the global terrestrial surface, but are largely under‐represented in studies of ecosystem carbon flux. Less than 2% of all FLUXNET eddy covariance sites exist in a
Dominant Trees in a Subtropical Forest Respond to Drought Mainly via Adjusting Tissue Soluble Sugar and Proline Content
Comparison between the drought treatments for each species indicated that the trees responded species-specific to the short-term and prolonged drought, with S. superba exhibiting larger plasticity and higher adaption than M. macclurei.
Giant cacti - isotopic recorders of climate variation in warm deserts of the Americas.
This work reviews the opportunities, challenges and pitfalls in measuring δ13C, δ2H and δ18O ratios captured in spine tissues and describes how the analysis of all three isotopes can be used in combination to provide potentially robust analysis of photosynthetic function in cacti, and other succulent-stemmed taxa across broad spatio-temporal environmental gradients.
Stable isotope physiology of stem succulents across a broad range of volume-to-surface area ratio
Examination of intrinsic physiological tradeoffs across diverse stem morphologies in three divergent evolutionary groups where stem succulence is common suggests that physiological tradeoff associated with stem V:S are detectable across broad evolutionary groups despite differences in CAM strength.
Could land‐based early photosynthesizing ecosystems have bioengineered the planet in mid‐Palaeozoic times?
The Ordovician and Silurian periods were times of major geological activity as regards palaeogeography, volcanism and climate change, the last of these evidenced by a series of cooling episodes and
The Physiological Effect of a Holoparasite Over a Cactus Along an Environmental Gradient
The data revealed that E. chiloensis response to T. aphyllus infection is sensitive to environmental changes in a way that could be strongly impacted by the desertification projected for this area due to climate change.


Stomatal responses to changes in air humidity are not necessarily linked to nocturnal CO2 uptake in the CAM plant Plectranthus marrubioides Benth. (Lamiaceae)
It is suggested that drought stress was necessary to increase responsiveness of plants to the point where CAM was also inhibited by decreases in air humidity, as well as net night-time carbon gain, nocturnal malic acid accumulation and, thus, relative carbon recycling.
Watering converts a CAM plant to daytime CO2 uptake
The tissue acidity decreases as the organic acids are decarboxylated during the day, when the internally released CO2 is prevented from leaving by the closed stomata, and thus the night-time stomatal opening of CAM plants leads to overall water conservation.
Influences of Seasonal Changes in Leaf Morphology on Water-Use Efficiency For Three Desert Broadleaf Shrubs
Simulated transpiration and photosynthesis for leaves with morphology characteristic of drier periods resulted in water—use efficiencies similar to those for natural conditions, but annual photosynthesis was reduced °24% for Encelia, 17% for Hyptis, and <2% for Mirabilis.
CO2 uptake by the cultivated hemiepiphytic cactus, Hylocereus undatus
Summary The climate of the native tropical forest habitats of Hylocereus undatus , a hemiepiphytic cactus cultivated in 20 countries for its fruit, can help explain the response of its net CO 2
Seasonal variation of net CO2uptake for cactus pear (Opuntia ficus-indica) and pitayo (Stenocereus queretaroensis) in a semi-arid environment
Abstract The objective of this work was to evaluate the effects of seasonal variation in temperature, irradiation, and soil moisture content on the photosynthetic rates of Opuntia ficus-indica and
How important are columnar cacti as sources of water and nutrients for desert consumers? A review
It is argued that the resources provided by saguaros do much to satisfy the energy and water requirements of the birds that reside in hot subtropical deserts during the summer, and an isotopic approach is described that allows quantifying the ecological importance of CAM succulents.
Water relations and photosynthesis of a barrel cactus, Ferocactus acanthodes, in the Colorado desert
  • P. Nobel
  • Environmental Science
  • 2004
The structural characteristics, water relations, and photosynthesis of Ferocactus acanthodes (Lemaire) Britton and Rose, a barrel cactus exhibiting Crassulacean acid metabolism (CAM), were examined in its native habitat in the western Colorado desert, indicating that cool nighttime temperatures are advantageous for gas exchange by F. acanthode.
The Carbon Dioxide Exchange
  • P. Reich
  • Environmental Science
  • 2010
Two papers in this issue contribute to understanding the land-atmosphere exchange by elegantly analyzing rich data sets on CO2 fluxes from a global network of monitoring sites.