Water Relations of Eucalyptus Marginata Sm. Under Natural Conditions

1967 ◽  
Vol 55 (3) ◽  
pp. 597 ◽  
Author(s):  
D. Doley
Keyword(s):  
Water Relations ◽  
Natural Conditions ◽  
Eucalyptus Marginata

Lichen carbon gain under tropical conditions: water relations and CO2 exchange of Lobariaceae species of a lower montane rainforest in Panama

2004 ◽  
Vol 36 (5) ◽  
pp. 329-342 ◽  
Author(s):  
Otto L. LANGE ◽  
Burkhard BÜDEL ◽  
Angelika MEYER ◽  
Hans ZELLNER ◽  
Gerhard ZOTZ
Keyword(s):  
Water Relations ◽  
Carbon Fixation ◽  
Nitrogen Concentration ◽  
Carbon Gain ◽  
Carbon Loss ◽  
Natural Conditions ◽  
Low Light ◽  
Green Algal ◽  
Tropical Conditions ◽  
Montane Rainforest

Diel (24-h) time courses of microclimate, water relations, and CO2 exchange were measured under quasi-natural conditions at a forest edge in a lower montane, tropical rainforest in Panama for six Lobariaceae (Lobaria crenulata, L. dissecta, Pseudocyphellaria aurata, P. intricata, Sticta sublimbata, S. weigelii). Responses to experimentally controlled water content (WC), photosynthetic photon fluence rate (PPFR), and temperature were studied in most detail with P. aurata.Photosynthesis was well adapted to high temperatures, and all species exhibited ‘shade plant’ characteristics with low light compensation points and low light saturation. Lobaria and Pseudocyphellaria species suffered from a strong depression of net photosynthesis (NP) at suprasaturating WC; suprasaturation depression was less in cyphellate Sticta species.Photosynthetic capacity correlated with thallus nitrogen concentration, and maximal NP rates of the cyanobacterial Sticta species was 4 to 5 times higher than that of the green algal Lobaria species. However, high rates of NP were uncommon and brief events under natural conditions; the different environmental factors were rarely optimal simultaneously. Similar to earlier observations with other rainforest lichens, NP ceased during the period of highest irradiation on most days due to desiccation. During moist periods low light often limited carbon fixation, and high thallus hydration was often detrimental to NP. In spite of these limitations the maximal daily integrated net photosynthetic carbon income (ΣNP) was quite high especially for the Sticta species [17·3 and 24·1 mgC (gC)−1 day−1 for S. sublimbata and S. weigelii, respectively]. High nocturnal carbon loss, due to high night temperatures and continuous hydration, resulted in frequent negative diel carbon balances (ΣC) in all species. The average nocturnal carbon loss amounted to 83 and 70% ΣNP for P. aurata and P. intricata, respectively and to 64 and 59% of ΣNP for S. sublimbata and S. weigelii, respectively. Their average diel ΣC was as high as 3·7 and 5·3 mgC (gC)−1 day−1. In contrast, ΣC was much lower for the other species, it amounted to only 0·18 mgC (gC)−1 day−1 for L. crenulata. Thus, the Sticta species stood out amongst the species studied for their most successful adaptation of photosynthetic productivity to the habitat conditions in the lower montane rainforest.

Water Relations of Root-Pruned Jarrah (Eucalyptus marginata Donn ex Smith) Saplings

1987 ◽  
Vol 35 (6) ◽  
pp. 653 ◽  
Author(s):  
DS Crombie ◽  
JT Tippett ◽  
DJ Gorddard
Keyword(s):  
Water Relations ◽  
Phytophthora Cinnamomi ◽  
Leaf Water ◽  
Lateritic Soil ◽  
Root Pruning ◽  
Deep Roots ◽  
Eucalyptus Marginata ◽  
Water Potentials ◽  
Severe Water Stress ◽  
Leaf Shedding

Roots were pruned from jarrah (Eucalyptus marginata Donn ex Smith) saplings to simulate the effects of root loss induced by Phytophthora cinnamomi Rands. Stomatal conductance was more sensitive to root loss than was leaf water potential. Stomatal conductances of trees on moist soils declined when more than 50% of roots were removed but were more variable and were affected more severely by root pruning when soils were dry. Predawn leaf water potentials were unaffected by removal of up to 80% of roots irrespective of whether surface soils were dry or moist. The effects of root pruning on midday water potentials were variable especially when soils were dry. Leaf shedding and efficient stornatal closure prevented severe water stress developing in leaves until nearly 90% of the roots had been removed. It is suggested that destruction of the deep 'sinker' roots by P. cinnamomi has greater effects on jarrah's water relations during summer than does loss of shallow roots. The deep roots are especially important as jarrah grows on highly developed lateritic soil profiles.

scholarly journals WATER RELATIONS IN THE CELL

1945 ◽  
Vol 29 (2) ◽  
pp. 73-78 ◽  
Author(s):  
W. J. V. Osterhout
Keyword(s):  
Water Relations ◽  
Ferric Chloride ◽  
Lead Acetate ◽  
Lead Nitrate ◽  
Inorganic Salts ◽  
Natural Conditions ◽  
Ellipsoid Bodies ◽  
Straight Rod

Chloroplasts may contract under natural conditions and give up water to the rest of the cell, thus indicating changes in metabolism or constitution. Such contractions may be produced experimentally. In Nitella the chloroplasts are ellipsoid bodies which, under natural conditions, may contract to spheres with a loss of volume. This may be brought about by lead acetate, ferric chloride, and digitonin: the contraction may occur while the cell is alive. The contraction in lead acetate is reversible (in lead nitrate little or no contraction occurs). In Spirogyra the chloroplast is a long, spirally coiled ribbon which may contract under natural conditions to a short nearly straight rod with a loss of volume. This can be brought about by inorganic salts and in other ways while the cell is still alive.

Comparative Studies in Selected Species of Eucalyptus Used in Rehabilitation of the Northern Jarrah Forest, Western Australia. II. Wood and Leaf Anatomy

1984 ◽  
Vol 32 (4) ◽  
pp. 375 ◽  
Author(s):  
RW Ridge ◽  
WA Loneragan ◽  
DT Bell ◽  
IJ Colquhoun ◽  
J Kuo
Keyword(s):  
Water Relations ◽  
Leaf Anatomy ◽  
Structural Features ◽  
Stomatal Resistance ◽  
Indigenous Species ◽  
Pressure Potential ◽  
Distinctive Character ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Xylem Pressure Potential

Previous studies have established differences in water relations between the major dominant of the northern jarrah forest, Eucalyptus marginata, which transpires freely except under conditions of extreme drought, and potential replacement species which exhibit some measure of stomatal control. The anatomy of the water-conducting system of three indigenous species (Eucalyptus marginata, E. calophylla and E. wandoo) and four eastern Australian species (E. globulus, E. maculata, E. resinifera and E. saligna) is described with reference to their patterns of stomatal resistance and xylem pressure potential. Vessel and parenchyma distribution generally correlated with taxonomic affinities of the species. Groups based on wood anatomy had little in common with groupings based on eco-physiological behaviour but did tend to confirm the distinctive character of E. marginata. By using leaf anatomy, a third grouping of species was possible. E. globulus, E. maculata and E. wandoo are amphistomatous whereas E. calophylla, E. resinifera, E. saligna and E. marginata are hypostomatous. However, the major structural features associated with previously observed patterns of water relations appear related to differences in vessel size (particularly in E. wandoo) and the presence and size of the stomatal antechambers. The anatomical structures described here confirm the special way in which E. rnarginata responds to environmental factors, and thus emphasize the challenge of finding a substitute species that exhibits similar anatomical and physiological adaptations.

Water relations of crok-oak (Quercus suber L.) under natural conditions

Vegetatio ◽  
1992 ◽  
Vol 99-100 (1) ◽  
pp. 199-208 ◽  
Author(s):  
G. Oliveira ◽  
O. A. Correia ◽  
M. A. Martins-Lou��o ◽  
F. M. Catarino
Keyword(s):  
Water Relations ◽  
Quercus Suber ◽  
Natural Conditions

scholarly journals Growth and water relations of Eucalyptus marginata (jarrah) stands in response to thinning and fertilization

1997 ◽  
Vol 17 (4) ◽  
pp. 267-274 ◽  
Author(s):  
G. L. Stoneman ◽  
D. S. Crombie ◽  
K. Whitford ◽  
F. J. Hingston ◽  
R. Giles ◽  
...  
Keyword(s):  
Water Relations ◽  
Eucalyptus Marginata

Water relations of cork-oak (Quercus suber L.) under natural conditions

1992 ◽  
pp. 199-208 ◽  
Author(s):  
G. Oliveira ◽  
O. A. Correia ◽  
M. A. Martins-Loução ◽  
F. M. Catarino
Keyword(s):  
Water Relations ◽  
Quercus Suber ◽  
Cork Oak ◽  
Natural Conditions
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