Effect of two forest grasses differing in their growth dynamics on the water relations and the growth of Quercus petraea seedlings

1996 ◽  
Vol 74 (10) ◽  
pp. 1562-1571 ◽  
Author(s):  
Catherine Collet ◽  
Henri Frochot ◽  
Jean-Marc Guehl ◽  
André Ferhi
Keyword(s):  
Water Stress ◽  
Carbon Isotope ◽  
Isotope Composition ◽  
Soil Water Potential ◽  
Bare Soil ◽  
Quercus Petraea ◽  
Grass Species ◽  
Basal Diameter ◽  
Root Interactions ◽  
Intrinsic Water Use Efficiency

Interference between 1-year-old sessile oak (Quercus petraea (Mattus.) Liebl.) seedlings and two grass species (Agrostis stolonifera L. and Deschampsia cespitosa (L.) Beauv.) was evaluated during 3 years after seedling transplantation. The seedlings were grown in large containers under crossed levels of watering regimes (regular irrigation that maintained the soil at field capacity or seasonal water stress) and grass competition (with Agrostis, Deschampsia, or bare soil). After 3 years, seedling basal diameter was 2.5 times greater in the absence of competing vegetation than with one of the two grasses. Within the grass-competition treatments, diameter was 1.3 times as great for the seedlings grown in the irrigated treatments than for the seedlings grown in the water-stressed treatments and was 1.3 times greater for the seedlings grown with Agrostis than for the seedlings grown with Deschampsia. During the first 2 years, the seedlings grew much faster in the bare soil than in the weedy treatments, whatever the watering level. During the 3rd year, the seedlings in all the irrigated treatments showed similar relative growth rate values, which were much higher than those in the water-stressed treatments. Each year, soil water potential reached −2.5 MPa under the two grasses and −0.7 MPa under bare soil by the end of summer. On the contrary, competition for nutrients seemed to be low. Assessments of plant carbon isotope composition showed that the seedlings in the weedy water-stressed treatments had higher intrinsic water-use efficiency, and also suggested that the competition exerted by the two grasses occurred mainly for water. We conclude that during the first 2 years, the negative effects of the two grass species on seedling growth seemed to be largely independent of any competition for water. Conversely, during the 3rd year, the influence of the grasses on the seedlings seemed to be related only to competition for water. Keywords: root interactions, water stress, osmotic adjustment, carbon isotope discrimination, classical growth analysis.

scholarly journals Multidecadal records of intrinsic water-use efficiency in the desert shrubEncelia farinosareveal strong responses to climate change

2020 ◽  
Vol 117 (31) ◽  
pp. 18161-18168 ◽  
Author(s):  
Avery W. Driscoll ◽  
Nicholas Q. Bitter ◽  
Darren R. Sandquist ◽  
James R. Ehleringer
Keyword(s):  
Water Stress ◽  
Water Use Efficiency ◽  
Carbon Isotope ◽  
Water Use ◽  
Isotope Ratios ◽  
Entire Study ◽  
Carbon Isotope Ratios ◽  
Population Mean ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

While tree rings have enabled interannual examination of the influence of climate on trees, this is not possible for most shrubs. Here, we leverage a multidecadal record of annual foliar carbon isotope ratio collections coupled with 39 y of survey data from two populations of the drought-deciduous desert shrubEncelia farinosato provide insight into water-use dynamics and climate. This carbon isotope record provides a unique opportunity to examine the response of desert shrubs to increasing temperature and water stress in a region where climate is changing rapidly. Population mean carbon isotope ratios fluctuated predictably in response to interannual variations in temperature, vapor pressure deficit, and precipitation, and responses were similar among individuals. We leveraged the well-established relationships between leaf carbon isotope ratios and the ratio of intracellular to ambient CO2concentrations to calculate intrinsic water-use efficiency (iWUE) of the plants and to quantify plant responses to long-term environmental change. The population mean iWUE value increased by 53 to 58% over the study period, much more than the 20 to 30% increase that has been measured in forests [J. Peñuelas, J. G. Canadell, R. Ogaya,Glob. Ecol. Biogeogr.20, 597–608 (2011)]. Changes were associated with both increased CO2concentration and increased water stress. Individuals whose lifetimes spanned the entire study period exhibited increases in iWUE that were very similar to the population mean, suggesting that there was significant plasticity within individuals rather than selection at the population scale.

scholarly journals Effect of Varying Crop Load on Leaf Photosynthesis and Carbon Isotope Discrimination of `Imperial Gala' Apple Tree

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1010C-1010
Author(s):  
Paolo Sabbatini ◽  
James Flore
Keyword(s):  
Water Stress ◽  
Carbon Isotope ◽  
Photosynthetic Rate ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Carbon Isotope Composition ◽  
Research Station ◽  
Crop Load ◽  
13C Discrimination ◽  
Source Limitation

Crop load (CL) is a critical regulator of production and quality on apple. It affects leaf photosynthetic rate and usually an increase is detected in leaves close to developing sinks. The objective of this work was to test if 13C discrimination during photosynthesis could be an indicator of carbon sink limitation. The natural plant carbon isotope composition (13C/12C ratio: d13C) is an indicator of water use efficiency and it is an effective tool to study environmental stresses in plants. Seven-year-old trees of Imperial Gala/Bud 9 (n=30), field-grown at the Clarksville Horticultural Research Station in Michigan, were hand-thinned to five levels of CL manipulating the leaf to fruit ratio (LFR: 4, 8, 16, 32, 64) after June drop. Net photosynthetic rate (A) of leaves was monitored daily during the season and elevated rates were observed in low LFR. The A was inhibited in low CL trees (LFR 32 and 64) more in the afternoon (from 20% to 42% in relation to normal CL: LFR 16) than in the morning (from 5% to 20%), and stomatal conductance declined over the afternoon. Shoot and fruit growth were affected (fruit size –11/+11%, shoot length –13/+18% from normal CL; LFR 16). Variations of the stable carbon isotope composition of leaves show a significant reduction of 13C discrimination in low CL trees (–3.2%: d13C –25.82) and an increase of 13C discrimination (+2.7%: d13C –27.38) in relation to normal CL trees (LFR 15.63). The results were similar to those reported in 2004, which imply isotopic discrimination in relation to source limitation. This is the opposite of what you would expect under water stress conditions. Although trees were well-watered during the season, the effect of water stress on apple trees and its interaction with source limitation will be discussed.

The influence of hydrodynamics on the carbon isotope composition of inorganically precipitated calcite

2021 ◽  
Vol 565 ◽  
pp. 116932
Author(s):  
Hao Yan ◽  
Wolfgang Dreybrodt ◽  
Huiming Bao ◽  
Yongbo Peng ◽  
Yu Wei ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Isotope Composition ◽  
Carbon Isotope Composition

scholarly journals Which Is More Sensitive to Water Stress for Irrigation Scheduling during the Maturation Stage: Grapevine Photosynthesis or Berry Size?

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 845
Author(s):  
Qingtao Zhang ◽  
Yixuan Chen ◽  
Yujiu Xiong ◽  
Shigeoki Moritani ◽  
Xinyu Wu ◽  
...  
Keyword(s):  
Water Stress ◽  
High Efficiency ◽  
Soil Water Potential ◽  
Net Photosynthesis ◽  
Development Stage ◽  
Irrigation Scheduling ◽  
Maturation Stage ◽  
Vitis Vinifera L ◽  
A Value ◽  
Berry Size

To better understand the sensitivity of berry size and grapevine photosynthesis to water stress, and determine the soil water potential (ψ) threshold for scheduling irrigation during the maturation stage, we simultaneously measured berry size with photographs, leaf net photosynthesis with a portable meter, and ψ with tensiometers during the drying cycles for grapevines (Vitis vinifera L.). Our results showed that in berry development stage III (maturation), photosynthesis was more sensitive to water stress than berry size. When ψ decreased beyond −13.2 ± 0.82 kPa, photosynthesis, stomatal conductance, transpiration, and extrinsic (AN/E) and intrinsic (AN/gs) water use efficiency (WUE) decreased rapidly and did not recover thereafter. In contrast, the berry size remained close to unaffected by the decreasing ψ until it reached a value of −16.2 ± 0.77 kPa and, thereafter, the berry shrank significantly. In conclusion, we suggest that during the maturation stage of grapevines, for the potted mixture used in our experiments, irrigation should be triggered when the ψ reaches a value of −13.2 ± 0.82 kPa. Further, ψ should be kept lower than −6.9 ± 0.15 kPa after irrigation, because the highest values of intrinsic WUE (AN/gs) occurred when ψ decreased from −6.9 ± 0.15 to −14.6 ± 0.7 kPa. In arid areas, the threshold ψ should be considered as −16.2 ± 0.77 kPa during maturation to achieve high-efficiency use of water resources and sustainable production of grapevines.

Sign in / Sign up

Export Citation Format

Share Document