Environmental controls of carbon uptake in two woody species with contrasting distributions at the edge of cliffs

1990 ◽  
Vol 68 (11) ◽  
pp. 2371-2380 ◽  
Author(s):  
U. Matthes-Sears ◽  
D. W. Larson
Keyword(s):  
Water Potential ◽  
Acer Saccharum ◽  
Deciduous Forest ◽  
Light Limitation ◽  
Carbon Gain ◽  
Carbon Uptake ◽  
Severe Drought ◽  
Xylem Water Potential ◽  
Thuja Occidentalis ◽  
Environmental Controls

Thuja occidentalis L. and Acer saccharum Marsh, show mutually exclusive distribution patterns along forested cliff edges of the Niagara Escarpment; T. occidentalis occurs at the cliff edge and on the cliff face, whereas A. saccharum occurs with increasing frequency away from the cliff edge. To reveal the controls of such patterns, seasonal and diurnal courses of net photosynthesis (Pn), stomatal conductance (gs), and xylem water potential were measured in situ and related to fluctuations in light, temperature, and moisture. For each species, saplings growing in the cedar zone near the cliff edge were compared with saplings growing in the deciduous forest zone farther from the cliff edge on the plateau. The carbon uptake of both species was most often limited by light; limitation by temperature, atmospheric, or soil moisture was rare. Acer saccharum was slightly better adapted than T. occidentalis to growth at the low light levels in both zones because of a greater light-use efficiency. During severe drought, both species showed reductions in Pn and gs when growing near the cliff edge. In the deciduous forest, in contrast, Pn of T. occidentalis, but not A. saccharum, was significantly reduced, suggesting that A. saccharum may outcompete T. occidentalis for water. In the spring and fall, T. occidentalis had higher Pn and gs in the deciduous forest than at the cliff edge. However, all differences in gas exchange rates between trees in the deciduous forest and at the cliff edge were small and relatively rare. During most of the growing season, Pn and gs differed little between saplings in the two zones. This suggests that the pattern of abundance is not controlled to a substantial degree by carbon gain at the sapling stage. Key words: photosynthesis, water potential, Acer saccharum, Thuja occidentalis, plant zonation, cliff–forest ecotone.

scholarly journals Optimal stomatal behavior with competition for water and risk of hydraulic impairment

2016 ◽  
Vol 113 (46) ◽  
pp. E7222-E7230 ◽  
Author(s):  
Adam Wolf ◽  
William R. L. Anderegg ◽  
Stephen W. Pacala
Keyword(s):  
Water Potential ◽  
Classical Theory ◽  
Plant Competition ◽  
Carbon Gain ◽  
Alternative Theory ◽  
Xylem Water Potential ◽  
Stomatal Behavior ◽  
Damage Repair ◽  
Functional Forms ◽  
Additional Water

For over 40 y the dominant theory of stomatal behavior has been that plants should open stomates until the carbon gained by an infinitesimal additional opening balances the additional water lost times a water price that is constant at least over short periods. This theory has persisted because of its remarkable success in explaining strongly supported simple empirical models of stomatal conductance, even though we have also known for over 40 y that the theory is not consistent with competition among plants for water. We develop an alternative theory in which plants maximize carbon gain without pricing water loss and also add two features to both this and the classical theory, which are strongly supported by empirical evidence: (i) water flow through xylem that is progressively impaired as xylem water potential drops and (ii) fitness or carbon costs associated with low water potentials caused by a variety of mechanisms, including xylem damage repair. We show that our alternative carbon-maximization optimization is consistent with plant competition because it yields an evolutionary stable strategy (ESS)—species with the ESS stomatal behavior that will outcompete all others. We further show that, like the classical theory, the alternative theory also explains the functional forms of empirical stomatal models. We derive ways to test between the alternative optimization criteria by introducing a metric—the marginal xylem tension efficiency, which quantifies the amount of photosynthesis a plant will forego from opening stomatal an infinitesimal amount more to avoid a drop in water potential.

Organization of the Niagara Escarpment cliff community. II. Characterization of the physical environment

1990 ◽  
Vol 68 (9) ◽  
pp. 1931-1941 ◽  
Author(s):  
R. M. Bartlett ◽  
U. Matthes-Sears ◽  
D. W. Larson
Keyword(s):  
Soil Moisture ◽  
Physical Environment ◽  
Acer Saccharum ◽  
Environmental Gradient ◽  
Deciduous Forest ◽  
Thuja Occidentalis ◽  
Active Radiation ◽  
Niagara Escarpment ◽  
Forest Habitats

In cliff-edge forests along the Niagara Escarpment, an array of species, including Thuja occidentals, is restricted to the cliff edge while different species, including Acer saccharum, are increasingly dominant away from the cliff on the plateau. This paper presents detailed analyses of 13 components of the physical environment, measured over an 18-month period, as they change across the plateau and towards the cliff edge. Statistically significant differences between the cliff-edge habitat and the adjacent deciduous forest were found in most of the 13 variables, and the results indicate a strong environmental gradient between the cliff edge and deciduous forest habitats. Lower and more rapidly fluctuating soil moisture levels combined with low photosynthetically active radiation at the cliff edge suggest that conditions there are frequently more severe for plants than in the deciduous forest in summer. Additionally, the cliff edge was snow free during the winter and the soils were frozen for a more protracted period than the deciduous forest soils. Soil and litter depths decreased significantly from the deciduous forest toward the cliff edge. The effects of these differences are discussed with reference to the characteristics of species that dominate the deciduous and coniferous cliff-edge zones. Key words: cliff, gradient, Thuja occidentalis, Acer saccharum, microclimate, Niagara Escarpment.

scholarly journals Leaf Conductance and Xylem Water Potential of Ecotypes and Cultivars of Acer saccharum and A. nigrum

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 649a-649
Author(s):  
Steve C. Yuza ◽  
Art L. Youngman ◽  
John C. Pair
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Soil Water Potential ◽  
Leaf Conductance ◽  
Physical Factors ◽  
Green Mountain ◽  
Xylem Water Potential ◽  
Old Trees

This study examined physical factors and physiological responses of five different ecotypes and cultivars of Acer saccharum and A. nigrum. The objective was to determine variations in leaf conductance and xylem water potential and correlations associated with their natural geographic distribution. Compared were two ecotypes of sugar maple, Caddo and Wichita Mountains, native to Oklahoma with cultivars Green Mountain and Legacy, plus black maple seedlings from Iowa. Measurements taken included leaf conductance, xylem water potential and soil water potential in a replicated block of 15-year-old trees. The two ecotypes had consistently higher photosynthetic rates, stomatal conductance and transpiration rates than other selections. Xylem water potentials were significantly higher for Caddo maples than Green Mountain, Legacy and Acer nigrum in both predawn and midday samples. This difference in water availability can be associated with a tendency for Caddo to vary its stomatal conductance. The other tree types maintained stable stomatal conductances.

scholarly journals Towards Vine Water Status Monitoring on a Large Scale Using Sentinel-2 Images

2021 ◽  
Vol 13 (9) ◽  
pp. 1837
Author(s):  
Eve Laroche-Pinel ◽  
Sylvie Duthoit ◽  
Mohanad Albughdadi ◽  
Anne D. Costard ◽  
Jacques Rousseau ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Potential ◽  
Large Scale ◽  
Water Status ◽  
Vegetation Indices ◽  
Machine Learning Algorithms ◽  
Severe Drought ◽  
Stem Water Potential ◽  
Stem Water ◽  
Sentinel 2

Wine growing needs to adapt to confront climate change. In fact, the lack of water becomes more and more important in many regions. Whereas vineyards have been located in dry areas for decades, so they need special resilient varieties and/or a sufficient water supply at key development stages in case of severe drought. With climate change and the decrease of water availability, some vineyard regions face difficulties because of unsuitable variety, wrong vine management or due to the limited water access. Decision support tools are therefore required to optimize water use or to adapt agronomic practices. This study aimed at monitoring vine water status at a large scale with Sentinel-2 images. The goal was to provide a solution that would give spatialized and temporal information throughout the season on the water status of the vines. For this purpose, thirty six plots were monitored in total over three years (2018, 2019 and 2020). Vine water status was measured with stem water potential in field measurements from pea size to ripening stage. Simultaneously Sentinel-2 images were downloaded and processed to extract band reflectance values and compute vegetation indices. In our study, we tested five supervised regression machine learning algorithms to find possible relationships between stem water potential and data acquired from Sentinel-2 images (bands reflectance values and vegetation indices). Regression model using Red, NIR, Red-Edge and SWIR bands gave promising result to predict stem water potential (R2=0.40, RMSE=0.26).

scholarly journals Mist Irrigation Reduces Post-transplant Desiccation of Bare-root Trees

1994 ◽  
Vol 12 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Rick M. Bates ◽  
Alex X. Niemiera
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Acer Platanoides ◽  
Sensitive Species ◽  
Xylem Water Potential ◽  
Post Transplant ◽  
Norway Maple ◽  
Relative Water ◽  
Bare Root ◽  
Cherry Trees

Abstract Desiccation during storage and reestablishment is a major factor contributing to poor regrowth of transplanted bare-root trees. The effect of overhead mist irrigation on reducing post transplant water stress in Norway maple (Acer platanoides L. ‘Emerald Lustre’) and Yoshino cherry (Prunus x yedoensis) was examined. Bare-root Norway maple (desiccation tolerant) and Yoshino cherry (desiccation sensitive) trees were transplanted into pine bark-filled containers and subjected to mist or non-mist treatments. Stem xylem water potential, relative water content, and survivability were determined. Xylem water potential increased (became less negative) for misted maple and cherry trees. Water potential increased for non-misted maple and decreased for non-misted cherry trees. Twenty-seven percent of non-misted cherries were evaluated as nonmarketable due to stem dieback compared to 0% for misted trees. Results of this study indicate that mist irrigation effectively reduces desiccation damage for desiccation sensitive species such as cherries and hawthorns.

scholarly journals Oak regeneration at the arid boundary of the temperate deciduous forest biome: insights from a seeding and watering experiment

2020 ◽  
Author(s):  
László Erdős ◽  
Katalin Szitár ◽  
Kinga Öllerer ◽  
Gábor Ónodi ◽  
Miklós Kertész ◽  
...  
Keyword(s):  
Deciduous Forest ◽  
Seedling Emergence ◽  
Deciduous Forests ◽  
Limiting Factors ◽  
Light Limitation ◽  
Pedunculate Oak ◽  
Forest Edges ◽  
Oak Regeneration ◽  
Temperate Deciduous ◽  
Forest Biome

AbstractTemperate deciduous forests dominated by oaks cover extensive areas in European lowlands. These ecosystems have been under intense anthropogenic use for millennia, thus their natural dynamics, and their regeneration in particular, is still not well understood. Previous studies found that pedunculate oak (Quercus robur), one of the most widespread and abundant species in European deciduous forests, regenerates in open habitats and forest edges, but not in closed forest interiors. However, these observations usually come from the core areas of the biome, and much less is known about such processes at its arid boundary, where limiting factors may be different, and climate change may first exert its effects.In a full factorial field experiment, we tested the effects of different habitats and increased growing season precipitation on the early regeneration of pedunculate oak in a forest-steppe ecosystem in Central Hungary, at the arid boundary of temperate deciduous forests. We planted acorns into three neighbouring habitats (grassland, forest edge, forest interior) and studied seedling emergence and plant performance under ambient weather and additional watering for four years.In the grassland habitat, seedling emergence was very low, and no seedlings survived by the fourth year. In contrast, seedling emergence was high and similar at forest edges and forest interiors, and was not affected by water addition. Most seedlings survived until the fourth year, with no difference between forest edge and forest interior habitats in numbers, and only minor or transient differences in size (leaf number, height).The lack of oak regeneration in the grassland contradicts previous reports on successful oak regeneration in open habitats, and may be related to a shift from light limitation to other limiting factors, such as moisture or microclimatic extremes, when moving away from the core of the deciduous forest biome towards its arid boundary. The similar number and performance of seedlings in forest edges and forest interiors may also be related to the decreasing importance of light limitation. The above-average precipitation in the year of seedling emergence (2016) might be a reason why watering had no effect on oak regeneration.Overall, our results highlight that oak regeneration and thus forest dynamics may be limited by different factors at a biome boundary compared to its core areas. Indeed, this very simple mechanism (inability of oak regeneration in grassland habitats) may contribute to the opening up of the closed forest biome, and the emergence of a biome transition zone.

Effects of water stress and soil type on photosynthesis, leaf water potential and yield of olive trees (Olea europaea L. cv. Chemlali Sfax)

2007 ◽  
Vol 47 (12) ◽  
pp. 1484 ◽  
Author(s):  
B. Ben Rouina ◽  
A. Trigui ◽  
R. d'Andria ◽  
M. Boukhris ◽  
M. Chaïeb
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Sandy Soil ◽  
Clay Soil ◽  
Sandy Loam ◽  
Leaf Water ◽  
Severe Drought ◽  
Relative Water ◽  
Olive Trees

In Tunisia, olives are grown under severe rain-fed, arid conditions. To determine the behaviour of olive trees (cv. Chemlali Sfax) during the severe drought affecting Tunisian arid areas in 2002, a range of physiological parameters were investigated in three adjacent orchards. Two olive orchards were rain-fed, one located on a sandy soil, and the other on a sandy-loam clay soil. A third orchard was also located on sandy soil, but received remedial irrigation (415 mm of water per year; ~40% of olive evapotranspiration). Predawn leaf water potential (Ψpd) did not fall below –1.52 MPa for irrigated olive trees. However, a large decrease in Ψpd was observed for rain-fed olive trees in the same period with Ψpd measured at about –3.2 MPa on sandy soil and –3.6 MPa on sandy-loam clay soil. At the same time, the minimal leaf water potential recorded at midday (Ψmin) decreased to –4.15 MPa and –4.71 MPa in the rain-fed trees for sandy and sandy-loam clay soil, respectively. For irrigated trees, the Ψmin was –1.95 MPa. These results were associated with relative water content, which varied from 80% for irrigated trees to 54 and 43.6%, respectively, for rain-fed trees and trees subjected to severe drought. In August, when the relative water content values were less than 50%, a progressive desiccation in the outer layer of canopy and death of terminal shoots were observed in trees, which grew on the sandy-loam clay soil. Furthermore, low soil water availability also affected (negatively) the net photosynthetic rate in rain-fed orchards (10.3 µmol/m2.s for irrigated trees v. 5.3 µmol/m2.s in rain-fed trees on sandy soil) and stomatal conductance (98.5 mmol/m2.s v. 69.3 mmol/m2.s). However, it improved water use efficiency (7.6 v. 4.7 µmol CO2/mmol H2O), which increased by more than 50% in both groups of rain-fed trees compared with the irrigated ones. We can conclude that olive trees respond to drought by showing significant changes in their physiological and biological mechanisms. These results also help our understanding of how olive trees cope with water stress in the field and how marginal soils can restrict growth and lower yields.

scholarly journals Carbon gain phenologies of spring‐flowering perennials in a deciduous forest indicate a novel niche for a widespread invader

2018 ◽  
Vol 221 (2) ◽  
pp. 778-788 ◽  
Author(s):  
J. Mason Heberling ◽  
Steven T. Cassidy ◽  
Jason D. Fridley ◽  
Susan Kalisz
Keyword(s):  
Deciduous Forest ◽  
Carbon Gain
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