Stem water transport and freeze-thaw xylem embolism in conifers and angiosperms in a Tasmanian treeline heath

Oecologia ◽  
2001 ◽  
Vol 127 (3) ◽  
pp. 314-320 ◽  
Author(s):  
Taylor S. Feild ◽  
Tim Brodribb
Keyword(s):  
Water Transport ◽  
Xylem Embolism ◽  
Freeze Thaw ◽  
Stem Water

Stem—Water Transport

1984 ◽  
pp. 17-17
Author(s):  
Janice Glimn-Lacy ◽  
Peter B. Kaufman
Keyword(s):  
Water Transport ◽  
Stem Water

scholarly journals Diverging Responses of Two Subtropical Tree Species (Schima superba and Cunninghamia lanceolata) to Heat Waves

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 513
Author(s):  
Luping Qu ◽  
Hans J. De Boeck ◽  
Huihua Fan ◽  
Gang Dong ◽  
Jiquan Chen ◽  
...  
Keyword(s):  
Water Transport ◽  
Tree Species ◽  
Heat Waves ◽  
Cunninghamia Lanceolata ◽  
Negative Effects ◽  
Xylem Embolism ◽  
Schima Superba ◽  
High Vapor ◽  
Use Efficiency ◽  
Coniferous Tree Species

The frequency and intensity of heat waves (HWs) has increased in subtropical regions in recent years. The mechanism underlying the HW response of subtropical trees remains unclear. In this study, we conducted an experiment with broad-leaved Schima superba (S. superba) and coniferous Cunninghamia lanceolata (C. lanceolata) seedlings to examine HW (5-day long) effects on stem water transport, leaf water use efficiency (WUE), morphology and growth, and to elucidate differences in the responses of both species. Our results indicated that HWs can significantly reduce hydraulic conductivity in both species. C. lanceolata experienced significant xylem embolism, with the percentage loss of conductivity (PLC) increasing by 40%, while S. superba showed a non-significant increase in PLC (+25%). Furthermore, HW also caused a reduction in photosynthesis rates (An), but transpiration rates (Tr) increased on the 5th day of the HW, together leading to a significant decrease in leaf WUE. From diurnal dynamics, we observed that the HW caused significant decrease of S. superba An only in the morning, but nearly the all day for C. lanceolata. During the morning, with a high vapor pressure deficit (VPD) environment, the HW increased Tr, which contributed a lot to latently cooling the foliage. In comparing the two tree species, we found that HW effects on S. superba were mostly short-term, with leaf senescence but limited or no xylem embolism. The surviving S. superba recovered rapidly, forming new branches and leaves, aided by their extensive root systems. For C. lanceolata, continued seedling growth initially but with subsequent xylem embolism and withering of shoots, led to stunted recovery and regrowth. In conclusion, apart from the direct thermal impacts caused by HW, drought stress was the main cause of significant negative effects on plant water transport and the photosynthetic system. Furthermore, S. superba and C. lanceolata showed clearly different responses to HW, which implies that the response mechanisms of broad-leaved and coniferous tree species to climate change can differ.

scholarly journals Stem water transport of Lithocarpus edulis, an evergreen oak with radial-porous wood

2005 ◽  
Vol 25 (2) ◽  
pp. 221-228 ◽  
Author(s):  
S. Hirose ◽  
A. Kume ◽  
S. Takeuchi ◽  
Y. Utsumi ◽  
K. Otsuki ◽  
...  
Keyword(s):  
Water Transport ◽  
Stem Water ◽  
Evergreen Oak

scholarly journals Multiple Ceratocystis smalleyi Infections Associated with Reduced Stem Water Transport in Bitternut Hickory

2013 ◽  
Vol 103 (6) ◽  
pp. 565-574 ◽  
Author(s):  
J.-H. Park ◽  
J. Juzwik ◽  
J. Cavender-Bares
Keyword(s):  
Flow Velocity ◽  
Water Transport ◽  
Sap Flow ◽  
Vascular System ◽  
Field Studies ◽  
Growth Rings ◽  
North Central ◽  
The North ◽  
Stem Water ◽  
Sap Flow Velocity

Hundreds of cankers caused by Ceratocystis smalleyi are associated with hickory bark beetle-attacked bitternut hickory exhibiting rapid crown decline in the north-central and northeastern United States. Discolored sapwood colonized by the fungus commonly underlies the cankers. Field studies were conducted to test the hypothesis that C. smalleyi infections cause vascular system dysfunction in infected trees. Fifty C. smalleyi inoculations made at 1.8 to 3.8 m in height on stems of healthy bitternut hickory trees (13 to 28 cm in diameter at 1.4 m in height) resulted in extensive canker formation and sapwood discoloration 12 to 14 months after treatment compared with water-inoculated and noninoculated controls. Sap flow velocity (midday) was significantly lower in the infected trees compared with that in the controls. Sap flow velocity also was inversely correlated with the proportion of bark area with cankered tissues and with tylose abundance in the youngest two growth rings. Tylose formation in current-year vessels associated with C. smalleyi infections is likely responsible for much of the water transport disruption. It is hypothesized that multiple stem infections of C. smalleyi and the resulting xylem dysfunction contribute to crown wilt development in bitternut hickory exhibiting rapid crown decline.

The thermodynamics of water transport in biological cells during a freeze-thaw protocol

Cryobiology ◽  
1974 ◽  
Vol 11 (6) ◽  
pp. 540-541
Author(s):  
O.M. Silvares ◽  
E.G. Cravalho ◽  
C.E. Huggins ◽  
W.M. Toscano
Keyword(s):  
Water Transport ◽  
Biological Cells ◽  
Freeze Thaw

The effects of Phytophthora ramorum infection on hydraulic conductivity and tylosis formation in tanoak sapwood

2009 ◽  
Vol 39 (9) ◽  
pp. 1766-1776 ◽  
Author(s):  
Bradley R. Collins ◽  
Jennifer L. Parke ◽  
Barb Lachenbruch ◽  
Everett M. Hansen
Keyword(s):  
Hydraulic Conductivity ◽  
Water Transport ◽  
Specific Conductivity ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Inoculation Site ◽  
Lithocarpus Densiflorus ◽  
Stem Water ◽  
Spread Of Infection ◽  
Flow Over Time

Tanoak ( Lithocarpus densiflorus (Hook. and Arn.) Rehder) is highly susceptible to sudden oak death, a disease caused by the oomycete Phytophthora ramorum Werres, De Cock & Man in’t Veld. Symptoms include a dying crown, bleeding cankers, and, eventually, death of infected trees. The cause of mortality is not well understood, but recent research indicates that water transport is reduced in infected trees. One possible mechanism causing the reduction in hydraulic conductivity is the presence of tyloses in xylem vessels. The development of tyloses was studied in relation to hydraulic conductivity in P. ramorum-infected sapwood. Inoculated logs showed a greater abundance of tyloses than noninoculated logs after 4 weeks. Inoculated trees with xylem infections had significantly more tyloses than noninoculated trees. In addition, the increase in number of tyloses was associated with a decrease in specific conductivity, suggesting that tyloses induced by infection with P. ramorum may interfere with stem sap flow. Over time, tylosis development increased in tissues farther from the inoculation site, in advance of the vertical spread of infection. The results suggest that infected sapwood contains numerous tyloses, which could significantly impede stem water transport.

Leaf hydraulic vulnerability protects stem functionality under drought stress in Salvia officinalis

2016 ◽  
Vol 43 (4) ◽  
pp. 370 ◽  
Author(s):  
Tadeja Savi ◽  
Maria Marin ◽  
Jessica Luglio ◽  
Francesco Petruzzellis ◽  
Sefan Mayr ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Transport ◽  
Salvia Officinalis ◽  
Summer Drought ◽  
Plant Organs ◽  
Transport Efficiency ◽  
Drought Tolerant ◽  
Hydraulic Vulnerability ◽  
Stem Water ◽  
Salvia Officinalis L

Functional coordination between leaf and stem hydraulics has been proposed as a key trait of drought-resistant plants. A balanced water transport efficiency and safety of different plant organs might be of particular importance for plant survival in the Mediterranean climate. We monitored seasonal changes of leaf and stem water relations of Salvia officinalis L. in order to highlight strategies adopted by this species to survive in harsh environmental conditions. During summer drought, the water potential dropped below the turgor loss point thus reducing water loss by transpiration, whereas the photosynthetic efficiency remained relatively high. Leaves lost their water transport efficiency earlier than stems, although in both plant organs P50 (water potential inducing 50% loss of hydraulic conductivity) indicated surprisingly high vulnerability when compared with other drought-tolerant species. The fast recovery of leaf turgor upon restoration of soil water availability suggests that the reduction of leaf hydraulic conductance is not only a consequence of vein embolism, but cell shrinkage and consequent increase of resistance in the extra-xylem pathway may play an important role. We conclude that the drought tolerance of S. officinalis arises at least partly as a consequence of vulnerability segmentation.

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