Influence of some environmental factors on indigenous earthworms in the northern jarrah forest of Western Australia

Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 271 ◽  
Author(s):  
I Abbott
Keyword(s):  
Western Australia ◽  
Negative Binomial ◽  
Predictor Variables ◽  
Annual Rainfall ◽  
Moderate Intensity ◽  
Total Biomass ◽  
Total Density ◽  
Indigenous Species ◽  
Frequency Of Occurrence ◽  
Jarrah Forest

Indigenous species of earthworms (Family Megascolecidae) are widely distributed throughout the northern jarrah forest of Western Australia. They occur not at random, but in an aggregated pattern well described by a negative binomial. Earthworms are only active in the topsoil (to depth of 5.5 cm) when soil moisture (gravimetric) exceeds 4%. This occurs from May until November. The number of species occurring in jarrah forest at any place, and the frequency of occurrence, biomass and density of earthworms, vary with average annual rainfall. In the zone of highest rainfall six or seven species occur together, frequency of occurrence is 40-60%, and total biomass and total density do not exceed 8 g m-2 and 40 m-2 respectively, and generally average much less. In the lowest rainfall zone only one or two species occur in any one locality, with total density much less than 10 m-2. Multiple regression analyses between four earthworm variables and 20 site and soil characteristics were highly successful in that up to three predictor variables yielded coefficients of determination exceeding 0.70. The most useful predictor variables were rainfall zone, forest basal area, soil pH and proportion of silt and clay in the topsoil (to depth of 15 cm). Recurrent low intensity (spring) fires and a single moderate intensity fire (summer) have minor direct and indirect effects on earthworms. Logging also has scant effect on their frequency of occurrence. The land use most adverse to earthworms is the clearing of forest for mining of bauxite or gravel. The effect on earthworms of clearing of forest and subsequent reforestation with pines varies: in one case there was an adverse effect, whereas in two others there was no difference.

Distribution of introduced earthworms in the norhtern jarrah forest of Western Australia

Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 263 ◽  
Author(s):  
I Abbott
Keyword(s):  
Forest Soil ◽  
Introduced Species ◽  
Western Australia ◽  
Eisenia Fetida ◽  
European History ◽  
Indigenous Species ◽  
Jarrah Forest ◽  
Exotic Trees ◽  
Aporrectodea Trapezoides ◽  
History Of

Five species of introduced earthworm were recorded in the northern jarrah forest of Western Australia during 1980-83. These are Aporrectodea trapezoides (Duges), A. caliginosa (Savigny), Eisenia fetida (Savigny), Octolasion cyaneum (Savigny) (all Lumbricidae) and Microscolex dubius (Fletcher) (Megascolecidae). A. trapezoides was recorded most frequently. These introduced species occur within the forest only where there has been major disturbance, especially where forest has been replaced by pasture, orchards or settlement. They have not been recorded in forest that has been logged or in plantations of exotic trees. Introduced species of earthworm were frequently found in association with indigenous species. Most individuals of A. trapezoides kept in jarrah forest soil in the laboratory lost weight over 30 days, in contrast to an indigenous species of earthworm. How and when earthworm species were introduced is discussed in terms of the early European history of the jarrah forest.

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.

Behavioural responses of Australian freshwater crayfish (Cherax cainii and Cherax albidus) to exotic fish odour

2006 ◽  
Vol 54 (6) ◽  
pp. 399 ◽  
Author(s):  
S. G. Height ◽  
G. J. Whisson
Keyword(s):  
Western Australia ◽  
Predatory Fish ◽  
Behavioural Plasticity ◽  
Current Debate ◽  
Freshwater Crayfish ◽  
Indigenous Species ◽  
Exotic Fish ◽  
Behavioural Responses ◽  
Invasive Crayfish ◽  
Australian Freshwater

Exotic finfish and crayfish have been translocated into Western Australia for more than 100 years. Deliberate stocking and subsequent escape from man-made impoundments have resulted in widespread distribution of non-native yabbies (Cherax albidus) and the exotic redfin perch (Perca fluviatilis) in the State’s south-west. Both species are considered invasive and are known to compete with indigenous species for resources. The nature and degree of impact on native marron (Cherax cainii) is unclear and the subject of current debate. Other researchers have hypothesised that invasive species modify their behaviour in the presence of predators in a more rapid and advantageous manner than native species. This greater behavioural plasticity can result in displacement of indigenous species and successful colonisation of invaders. The aim of this study was to investigate behavioural responses of an indigenous crayfish (C. cainii) and an invasive crayfish (C. albidus) to odours from a native predator (Tandanus bostocki) and an exotic predatory fish (P. fluviatilis) present in Western Australia. Crayfish behaviour was observed in individual glass tanks following the addition of odours from native (T. bostocki) or exotic (P. fluviatilis) finfish predators. Marron exhibited minor behavioural modifications when presented with odours from native or exotic finfish. In contrast, the invasive yabby showed greater detection of odours, displaying significant changes in behaviour (P < 0.05). Yabbies also appeared to distinguish between food odour (commercial crayfish feed) and predator odour; however, neither marron nor yabbies displayed behaviour indicating that they could distinguish between a native or exotic fish predator. Results support the hypothesis that invasive crayfish species have a greater capacity for behavioural plasticity than non-invasive crayfish.

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.

Partitioning of Food and Niche Characteristics of Coexisting Accipiter During Breeding

The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 761-779 ◽  
Author(s):  
Richard T. Reynolds ◽  
E. Charles Meslow
Keyword(s):  
Prey Size ◽  
The State ◽  
Total Density ◽  
Frequency Of Occurrence ◽  
Number Of Species ◽  
Accipiter Striatus ◽  
Shrub Canopy ◽  
Northern Goshawks ◽  
Nesting Season ◽  
Cooper's Hawks

AbstractThe abundance of resources and their use by Accipiter in two areas within Oregon from 1969 through 1974 are presented. In the coastal mountains of northwestern Oregon only Sharp-shinned Hawks (Accipiter striatus) and Cooper's Hawks (A. cooperii) nested. In the remainder of the state, A. striatus, A. cooperii, and Northern Goshawks (A. gentilis) were syntopic during the nesting season. The number of species and the total density of birds in eastern Oregon were about one-half those in northwestern Oregon. Mean prey size of A. striatus in northwestern Oregon (12.8 g) was significantly smaller than that of the same species in eastern Oregon (28.4 g). Accipiter striatus diets in both areas were composed almost entirely of birds (<5% mammals). Mean prey size of A. cooperii in both areas was nearly the same (134.7 g vs. 136.3 g) and was significantly larger than mean prey size of A. striatus. The frequency of occurrence and the size of prey taxa in A. cooperii diets, however, varied between areas: 74% birds (x̄ = 79.2 g) and 25% mammals (x̄ = 296.4 g) in northwestern Oregon versus 47% birds (x̄ = 123.7 g) and 53% mammals (x̄ = 147.5 g) in eastern Oregon. Mean prey size of A. gentilis in eastern Oregon (306.6 g) was significantly larger than that of A. cooperii and consisted of 55% birds (x̄ = 195.5 g) and 45% mammals (x̄ = 445.2 g). An analysis of prey sizes, prey taxa, and foraging heights indicated that, in general, food was partitioned in both areas primarily according to prey size. In eastern Oregon, however, where A. cooperii and A. gentilis overlapped broadly in prey size, these species tended to take different prey taxa. Both A. cooperii and A. gentilis foraged primarily in the lower zones (ground-shrub and shrub-canopy), whereas A. striatus foraged in the upper canopy.

Sign in / Sign up

Export Citation Format

Share Document