Desert dogma revisited: coupling of stomatal conductance and photosynthesis in the desert shrub, <i>Larrea tridentata</i>

Ogle, Kiona; Reynolds, James F.

doi:10.1046/j.1365-3040.2002.00876.x

Cited by 67 publications

(61 citation statements)

References 78 publications

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“…Although previous studies have demonstrated growth temperature effects on stomatal function (Ogle and Reynolds 2002, and references therein), our results showed no evidence of a growth temperature effect on conductance or transpiration at 18 or 28°C or at maximum photosynthetic rate. Even though we did not find direct effects of growth temperature on conductance, transpiration is inevitably higher at higher temperatures, and when coupled with the decline in photosynthetic capacity in plants grown at high temperatures results in a significant reduction in WUE at the higher growth temperature.…”

Section: Discussioncontrasting

confidence: 96%

Leaf shape linked to photosynthetic rates and temperature optima in South African Pelargonium species

et al. 2007

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The thermal response of gas exchange varies among plant species and with growth conditions. Plants from hot dry climates generally reach maximal photosynthetic rates at higher temperatures than species from temperate climates. Likewise, species in these environments are predicted to have small leaves with more-dissected shapes. We compared eight species of Pelargonium (Geraniaceae) selected as phylogenetically independent contrasts on leaf shape to determine whether: (1) the species showed plasticity in thermal response of gas exchange when grown under different water and temperature regimes, (2) there were differences among more- and less-dissected leafed species in trait means or plasticity, and (3) whether climatic variables were correlated with the responses. We found that a higher growth temperature led to higher optimal photosynthetic temperatures, at a cost to photosynthetic capacity. Optimal temperatures for photosynthesis were greater than the highest growth temperature regime. Stomatal conductance responded to growth water regime but not growth temperature, whereas transpiration increased and water use efficiency (WUE) decreased at the higher growth temperature. Strikingly, species with more-dissected leaves had higher rates of carbon gain and water loss for a given growth condition than those with less-dissected leaves. Species from lower latitudes and lower rainfall tended to have higher photosynthetic maxima and conductance, but leaf dissection did not correlate with climatic variables. Our results suggest that the combination of dissected leaves, higher photosynthetic rates, and relatively low WUE may have evolved as a strategy to optimize water delivery and carbon gain during short-lived periods of high soil moisture. Higher thermal optima, in conjunction with leaf dissection, may reflect selection pressure to protect photosynthetic machinery against excessive leaf temperatures when stomata close in response to water stress.

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Section: Discussioncontrasting

confidence: 96%

Leaf shape linked to photosynthetic rates and temperature optima in South African Pelargonium species

et al. 2007

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“…This supports a growing body of literature on the importance of effects of soil texture on water and nutrient relations in arid and semiarid ecosystems (McAuliffe 1994;Hamerlynck et al 2000Hamerlynck et al , 2002Hook and Burke 2000;Barrett and Burke 2002). Finally, the similarity in leaf N within species, coupled with differences in patterns of covariation between d 13 C with C pd and leaf N between species, indicates that stomatal closure appears to drive differences in d 13 C. This supports recent modeling and empirical work demonstrating that stomatal response to C pd , not mesophyll demand, largely controls differences in water use strategies in desert shrubs (Ogle and Reynolds 2002;Hamerlynck et al 2004). …”

Section: International Journal Of Plant Sciencessupporting

confidence: 80%

Plant Responses to an Edaphic Gradient across an Active Sand Dune/Desert Boundary in the Great Basin Desert

Rosenthal

Ludwig

Donovan

2005

International Journal of Plant Sciences

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In arid ecosystems, variation in precipitation causes broad-scale spatial heterogeneity in soil moisture, but differences in soil texture, development, and plant cover can also create substantial local soil moisture heterogeneity. The boundary between inland desert sand dunes and adjacent desert habitats exhibits abrupt changes in soil and vegetation characteristics that may be associated with differences in plant-available water and nutrients. We hypothesized that differences in plant water status between habitats would mirror changes in soil texture and vegetation cover. Because the dunes have higher water availability, we predicted that plants on dunes would have higher plant water potential (C) and be less water use efficient than plants off dunes. We tested these predictions for three species-Psoralidium lanceolatum (a C 3 perennial N-fixing subshrub), Stipa hymenoides (a C 3 perennial bunchgrass), and Salsola iberica (a C 4 annual)-on actively moving desert dunes and adjacent stabilized dunes at Little Sahara Dunes, Utah. Plants on the dunes maintained higher predawn (C pd ) water potentials (>ÿ1.5 MPa) throughout the summer season, whereas off-dune plants were water stressed from July on (C pd < ÿ1:5 MPa). Midday water potential (C md ) generally mirrored C pd . As predicted, off-dune plants were more water use efficient, on the basis of leaf carbon isotope ratios (d 13 C) for the C 3 species. The observed differences in soil particle size, soil water content, and the concomitant effect on soil C likely explain the observed differences in C pd . Soil N was significantly lower on dunes, while soil P was similar across habitats. In contrast, leaf N was similar across habitats, but leaf P was significantly higher on dunes, possibly because of species-specific differences in nutrient relations or differences in habitat nutrient availability. Abrupt changes in water and nutrient availability associated with soil texture are likely to be important selective forces shaping plants' strategies in this and other desert boundary communities.

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“…The ensuing slow development of leaf area per unit ground area should result in low maximum rates of transpiration and a conservative water use. Furthermore, a study of stomatal conductance in Larrea shrubs in New Mexico [Ogle and Reynolds, 2002] found that conductance is confined to the range 0.0 -0.1 mol m À2 s…”

Section: W06d02mentioning

confidence: 99%

Tragedy of the commons in plant water use

Zea-Cabrera

Iwasa

Levin

et al. 2006

Water Resources Research

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In this paper we address the following question: how can efficient water use strategies evolve and persist when natural selection favors aggressive but inefficient individual water use? A tragedy of the commons, in which the competitive evolutionary outcome is lower than the ecosystem optimum (in this case defined as maximum productivity), arises because of (1) a trade‐off between resource uptake rate and resource use efficiency and (2) the open access character of soil water as a resource. Competitive superiority is determined by the lowest value of the steady state soil moisture, which can be minimized by increasing water uptake or by increasing drought tolerance. When the competing types all have the same drought tolerance, the most aggressive water users exclude efficient ones, even though they produce a lower biomass when in monoculture. However, plants with low water uptake can exclude aggressive ones if they have enough drought tolerance to produce a lower steady state soil moisture. In that case the competitive superior is also the best monoculture, and there is no tragedy of the commons. Spatial segregation in soil moisture dynamics favors the persistence of conservative water use strategies and the evolution of lower maximum transpiration rates. Increasing genetic relatedness between competing plants favors the evolution of conservative water use strategies. Some combinations of soil moisture spatial segregation and intensity of kin selection may favor the evolution and maintenance of multiple types of plant water use. This occurs because a cyclical pattern of species replacement can arise where no single type can exclude all other types.

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Desert dogma revisited: coupling of stomatal conductance and photosynthesis in the desert shrub, Larrea tridentata

Cited by 67 publications

References 78 publications

Leaf shape linked to photosynthetic rates and temperature optima in South African Pelargonium species

Leaf shape linked to photosynthetic rates and temperature optima in South African Pelargonium species

Plant Responses to an Edaphic Gradient across an Active Sand Dune/Desert Boundary in the Great Basin Desert

Tragedy of the commons in plant water use

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