Comparative Studies in Selected Species of Eucalyptus Used in Rehabilitation of the Northern Jarrah Forest, Western Australia. I. Patterns of Xylem Pressure Potential and Diffusive Resistance of Leaves

1984 ◽  
Vol 32 (4) ◽  
pp. 367 ◽  
Author(s):  
IJ Colquhoun ◽  
RW Ridge ◽  
DT Bell ◽  
WA Loneragan ◽  
J Kuo
Keyword(s):  
Western Australia ◽  
Water Loss ◽  
Seasonal Patterns ◽  
Pressure Potential ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Xylem Pressure ◽  
Diffusive Resistance ◽  
Xylem Pressure Potential ◽  
The Impact

Land use which reduces tree canopy density and the impact of Phytophthora cinnamomi are believed to be altering the hydrological balance of parts of the northern jarrah forest, Western Australia. In the drier eastern zones of the forest, replacement plant communities must maintain the soil-salt-water balance to prevent significant increases in salinization of streams in water supply catchments. Daily and seasonal patterns of the diffusive resistance of leaves and xylem pressure potential were determined for the major natural dominant of the region, Eucalyptus marginata, and five other species of Eucalyptus used in rehabilitation. Three types of daily and seasonal patterns were observed. E. marginata and E. calophylla exhibited little stomatal control of water loss, and leaf resistances remained low throughout the study period (type 1). E. maculata, E. resinifera and E. saligna exhibited marked stomatal regulation during summer days when xylem pressure potentials fell below -2.O MPa (type 2). E. wandoo (type 3) also controlled water loss but developed xylem pressure potentials far lower than all other species tested (<-3.0 MPa). Although none of the species tested replicated the summer stomatal resistance and xylem pressure potential patterns of E. marginata, it is suggested that total annual water use should be examined before selecting the most appropriate species to rehabilitate disturbed sites in the eastern zones of the northern jarrah forest region.

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.

Effects of drying soils on survival of young Piceaglauca seedlings

1982 ◽  
Vol 12 (4) ◽  
pp. 1006-1009 ◽  
Author(s):  
E. C. Tear ◽  
K. O. Higginbotham ◽  
J. M. Mayo
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Water Loss ◽  
Growing Season ◽  
Combined Effects ◽  
Pressure Potential ◽  
Greenhouse Soil ◽  
Soil Mixture ◽  
Xylem Pressure ◽  
Xylem Pressure Potential

Drought stress is often suggested as a factor preventing successful field establishment of seedlings of white spruce (Piceaglauca (Moench) Voss) during their first growing season. In this study the combined effects of water stress and seedbed type on 1- and 3-month-old seedlings were examined. Shoot xylem pressure potential decreased to −1.5 MPa in seedlings grown in a greenhouse soil mixture in 9.5 days but took 18.5 days to reach this level in peat. Mortality reached 100% for 1-month-old seedlings grown in greenhouse mix 11 days after watering ceased, while it took 23 days to reach this level in peat. Shoot xylem pressure potentials can be used to predict mortality potential on the two seedbed types. Three-month-old seedlings on either seedbed survived for at least 31 days without watering, indicating development of capability for control of water loss with time.

Tree Species Preferences of Foraging Birds in Jarrah Forest in Western Australia.

1985 ◽  
Vol 12 (3) ◽  
pp. 461 ◽  
Author(s):  
I Abbott ◽  
PV Heurck
Keyword(s):  
Western Australia ◽  
Tree Species ◽  
Bird Species ◽  
Selective Logging ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Silvicultural Treatments ◽  
Species Preferences

A study of foraging by 10 bird species suggests that selective logging of large Eucalyptus marginata will only have affected Melithreptus lunatus, but that proposed silvicultural treatments, including removal of Banksia grandis, may affect several other bird species.

Critical Period of Weed Interference in Transplanted Tomatoes (Lycopersicon esculentum): Growth Analysis

Weed Science ◽  
1983 ◽  
Vol 31 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Susan E. Weaver ◽  
Chin S. Tan
Keyword(s):  
Lycopersicon Esculentum ◽  
Critical Period ◽  
Growth Analysis ◽  
Canopy Temperature ◽  
Dry Weight ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Fruit Number ◽  
Weed Interference ◽  
Xylem Pressure Potential

The critical period of weed interference in transplanted tomatoes (Lycopersicon esculentumMill. 'Springset’) was from 28 to 35 days after transplanting. A single weeding during this period was sufficient to prevent yield reductions. A growth analysis revealed that significant differences in plant dry weight and fruit number between tomatoes from weed-free and weed-infested plots were not apparent until 56 to 70 days after transplanting. The shorter the initial weed-free period, or the longer weeds were allowed to remain in the plots before removal, the earlier reductions in tomato dry weight and fruit number appeared. Weed interference was due primarily to shading rather than water stress. Tomatoes from weed-infested plots had significantly lower stomatal conductances than those from weed-free plots, but did not differ in xylem-pressure potential or in canopy temperature. If tomatoes were kept weed-free for more than 28 days, or when weeds were present for less than 28 days after transplanting, stomatal conductances were not significantly reduced.

Distribution of Phytophthora cinnamomi in the northern jarrah (Eucalyptus marginata) forest of Western Australia in relation to dieback age and topography

2002 ◽  
Vol 50 (1) ◽  
pp. 107 ◽  
Author(s):  
K. L. McDougall ◽  
G. E. St J. Hardy ◽  
R. J. Hobbs
Keyword(s):  
Spatial Distribution ◽  
Western Australia ◽  
Aerial Photography ◽  
Phytophthora Cinnamomi ◽  
Ex Situ ◽  
Patchy Distribution ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Almost All

The spatial distribution of Phytophthora cinnamomi Rands at seven dieback sites in the jarrah (Eucalyptus marginata Donn. ex Smith) forest of Western Australia was determined by the following two baiting techniques: in situ baiting with live Banksia grandis Willd. seedlings and ex situ baiting of sampled soil and root material. Four areas within each site were sampled, reflecting dieback age and position in the landscape. Approximate dieback ages of 50, 20 and 5 years were determined by aerial photography. The 50-year-old age class was divided into wet valley floor and dry gravelly slope. Phytophthora cinnamomi was recovered most frequently from the 5-year-old (dieback fronts) and wet 50-year-old areas by both baiting techniques. It was recovered from more than twice as many areas and about five times as many samples when in situ B. grandis baits were used compared with ex situ soil and root baiting. Almost all recoveries from in situ baits were made between October and December. From both methods, it appears that P. cinnamomi has a patchy distribution within dieback sites in the northern jarrah forest. It is easily detected only on dieback fronts and wet valley floors. On dry gravelly sites affected 20 years or more ago, P. cinnamomi is rare and may even be absent at some sites. This makes confident detection of the pathogen difficult. In situ baiting at least allows a temporal component to the sampling and will be a useful method of detection in areas where P. cinnamomi is rare or transient.

Stomatal control and the development of water deficit in Engelmann spruce seedlings during drought

1979 ◽  
Vol 9 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Merrill R. Kaufmann
Keyword(s):  
Flux Density ◽  
Stomatal Closure ◽  
Absolute Humidity ◽  
Pressure Potential ◽  
Evaporative Demand ◽  
Xylem Pressure ◽  
Full Sunlight ◽  
Engelmann Spruce ◽  
Xylem Pressure Potential ◽  
The Relationship

The effects of soil drying on water relations of Engelmann spruce (Piceaengelmannii Engelm.) were studied by withholding water from 4-year-old potted seedlings in full sunlight and under a shade screen transmitting 55–60% light. During a period of 2 months, xylem pressure potential, water vapor conductance, and transpirational flux density gradually declined compared with well watered controls, with drying being more rapid in full sunlight. As drying progressed, xylem pressure potential at 0 transpiration (predawn potential) decreased and the slope of the relationship between xylem pressure potential and transpirational flux density became more negative. Hysteresis in the relationship occurred when predawn xylem pressure potential was −6 bars (1 bar = 105 Pa) or lower. Needle conductance during daylight hours decreased as the absolute humidity difference from leaf to air increased but conductances were lower in September than in August for given humidity differences. Xylem pressure potentials between −15 and −19 bars had no clear effect on conductance in August but apparently caused significant stomatal closure in September. Because of humidity-induced stomatal closure, evaporative demand had little effect on transpirational flux density over a broad range of humidity gradient. Thus increased leaf-to-air vapor gradients for transpiration are not always accompanied by increased transpiration.

scholarly journals Feeding activity of threatened black cockatoos in mine-site rehabilitation in the jarrah forest of south-western Australia

2013 ◽  
Vol 61 (2) ◽  
pp. 119 ◽  
Author(s):  
Jessica Lee ◽  
Hugh Finn ◽  
Michael Calver
Keyword(s):  
Western Australia ◽  
Feeding Activity ◽  
Vegetation Succession ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Mine Site ◽  
Rehabilitation Protocols ◽  
Small Scales ◽  
Site Rehabilitation ◽  
Feeding Trace

Land clearing threatens three black cockatoo species (forest red-tailed black cockatoo, (Calyptorhynchus banksii naso), Carnaby’s cockatoo (Calyptorhynchus latirostris), and Baudin’s cockatoo (Calyptorhynchus baudinii) endemic to south-western Australia, so revegetation is important to their recovery. Over three years we studied cockatoo activity in 7–14-year-old mine-site rehabilitation in the region’s jarrah (Eucalyptus marginata)–marri (Corymbia calophylla) forest to give the most detailed description to date of the use of rehabilitation by the birds. Pits varied floristically and structurally (despite similar rehabilitation prescriptions), but interior and exterior plots (100 m2) were similar within pits. Using feeding traces (e.g. chewed husks), and behavioural observations we confirmed feeding within eight years of revegetation. Plots containing feeding trace were similar to plots without, so factors determining black cockatoo feeding may not be apparent at small scales. Returning food resources reflected vegetation succession, with regenerating marri and fast-maturing proteaceous species providing most food. Carnaby’s cockatoo ate Banksia and Hakea seeds and Baudin’s cockatoo and the forest red-tailed black cockatoo consumed marri seeds. Banksia squarrosa, Hakea undulata, H. prostrata and marri were common foods in all years. Revegetation efforts elsewhere should consider these species, within the constraints of rehabilitation protocols addressing multiple aims.

Water relations of loblolly pine trees in southeastern Oklahoma following precommercial thinning

1990 ◽  
Vol 20 (9) ◽  
pp. 1508-1513 ◽  
Author(s):  
Bert M. Cregg ◽  
Thomas C. Hennessey ◽  
Philip M. Dougherty
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
Loblolly Pine ◽  
Soil Water Potential ◽  
Basal Area ◽  
Leaf Conductance ◽  
Pressure Potential ◽  
Precommercial Thinning ◽  
Xylem Pressure ◽  
Xylem Pressure Potential

Xylem pressure potential, leaf conductance, transpiration, and soil moisture were measured during three summers following precommercial thinning of a 10-year-old stand of loblolly pine (Pinustaeda L.) in southeastern Oklahoma. The stand was thinned to three target basal-area levels: 5.8, 11.5, and 23 m2•ha−1 (control). Soil water potential increased significantly in response to thinning during the summer of each year studied. However, plant water relations were relatively unaffected by the treatments. Significant thinning effects on diurnal xylem pressure potential were observed on only 7 of 55 measurement periods. Treatment differences in conductance and transpiration observed during the first year of the study appeared to be related to differences in light interception and crown exposure. Regression analysis indicated response of leaf conductance and transpiration to predawn xylem pressure potential and vapor pressure deficit was not affected by the thinning treatments. Overall, the results of this study are consistent with a hypothesis in which transpiration, leaf area, and water potential interact to form a homeostatic relationship.

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