The dynamics of a Mitchell grass (Astrebla spp.) rangeland on the Barkly Tableland, Northern Territory.

1984 ◽  
Vol 6 (2) ◽  
pp. 92 ◽  
Author(s):  
BD Foran ◽  
G Bastin
Keyword(s):  
Water Treatment ◽  
Northern Territory ◽  
Seasonal Effect ◽  
Basal Cover ◽  
Standing Biomass ◽  
Average Rainfall ◽  
Total Plant

The response of an area of Astrebla grassland at Helen Springs Station on the Barkly Tableland to the treatments of exclosure and distance from water were studied from 1974 to 1979. The seasonal effect produced by a number of above average rainfall years was greater than the effects of exclosure and distance from water. The total standing biomass varied from 940 kg hdl in 1974 to 2258 kg ha-' in 1979. Both Aristida latifolia and Astrebla pectinata increased in standing biomass and basal cover while the annual Iseilema vaginiflorunz decreased. Apparent responses of some species to the distance from water treatment were explained by local vegetation patterning within a seemingly uniform grassland. Regression relationships were developed that related basal cover to both species and total plant standing biomass.

Studies of Central Australian Semidesert Rangelands. I. Range Condition and the Biomass Dynamics of the Herbage Layer and Litter.

1981 ◽  
Vol 29 (2) ◽  
pp. 219 ◽  
Author(s):  
MH Friedel
Keyword(s):  
Botanical Composition ◽  
Production Rates ◽  
Decomposition Rates ◽  
Litter Biomass ◽  
Range Condition ◽  
Standing Biomass ◽  
Average Rainfall ◽  
Biomass Dynamics ◽  
Condition Assessments ◽  
Herbage Layer

Following a sequence of years of above-average rainfall, standing biomass, rates of production and quantities of litter were high in the ground storey of three central Australian rangeland plant communities. Standing biomass was of the order of 4000 kg ha-1 in Astrebla grasslands, 2600 kg ha-1 in open woodlands and 1300 kg ha-1 in Acacia shrublands, and litter biomass was c. 1300 kg ha-1, 1600 kg ha-1 and 4000 kg ha-1 respectively. Levels of biomass and production rates were comparable with those of some semiarid and temperate sown pastures in average seasons, but they appeared to have reached their natural limit. Total standing biomass, production rates, species diversity, litter biomass and decomposition rates were not correlated with range condition assessments of the experimental sites. Species frequency was the only characteristic measured which was related to range condition other than botanical composition, the basis of site selection.

Agronomic studies on the productivity of kenaf (Hibiscus cannabinus L. cv. Guatemala 4) under rainfed and irrigated conditions in the Northern Territory

1990 ◽  
Vol 30 (3) ◽  
pp. 395 ◽  
Author(s):  
RC Muchow ◽  
JD Sturtz ◽  
MF Spillman ◽  
GE Routley ◽  
S Kaplan ◽  
...  
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Northern Territory ◽  
Growth And Yield ◽  
Stem Length ◽  
Yield Potential ◽  
Yield Response ◽  
Rainfall Season ◽  
Wide Range ◽  
Average Rainfall

Field experiments were conducted at Berrimah, Douglas Daly and Katherine in the Northern Territory (NT) during the 1987-88 and 1988-89 wet seasons to obtain yield data for kenaf (Hibiscus cannabinzis L. cv. Guatemala 4) grown under rainfed and irrigated conditions. Under rainfed conditions, maximum stem yield was obtained from sowings early in the wet season. Yield decreased with delay in sowing until the late-December-January period. The maximum rainfed stem yield at Katherine in an above-average rainfall season was 18 400 kg/ha. The maximum yield in a below average rainfall season was 11 700 kg/ha at Katherine, 9200 kg/ha at Douglas Daly and 9400 kg/ha at Berrimah. The applicability to the NT of growth and yield relationships established for irrigated kenaf in the Ord Irrigation Area (OIA) was assessed. The yield potential under irrigated conditions in the NT (21 600 kg/ha at 131 days after sowing) was higher than that reported elsewhere in Australia for the same growth period, but similar to that reported elsewhere for longer growth duration (180-300 days). In the NT, in contrast to the OIA, stem yield showed little or no response to N fertilisation. Stem yield was not related to N uptake, and at high levels of N application, there was marked N accumulation in the stem. Kenaf was able to accumulate up to 110 kg N/ha from the soil reserve where no N was applied. The yield response to plant density varied with the yield level and was similar to that in the OIA. Bark and core yield could be estimated directly from biomass, and indirectly from stem length and plant density, over a wide range of yield levels and cultural conditions. It was concluded that data relating to yield potential and response to N fertilisation cannot be transferred directly from the OIA to the NT.

A new relictual species of Earthworm (Oligochaeta: Megascolecidae) from Central Australia

Zootaxa ◽  
2019 ◽  
Vol 4700 (1) ◽  
pp. 146-150
Author(s):  
GEOFFREY R. DYNE
Keyword(s):  
Wide Distribution ◽  
Northern Territory ◽  
The West ◽  
Average Rainfall ◽  
Central Australia

Graliophilus zeilensis is described from Mount Zeil in the West MacDonnell Ranges. While Mt Zeil is the highest mountain in the Northern Territory of Australia, the average rainfall for the bioregion is less than 250 mm annually, well below the limit previously thought to support native earthworms. This record considerably extends the range of Graliophilus, which was formerly restricted to southern Australia. It also provides further evidence of a former continent-wide distribution of earthworms which has been confined to increasingly smaller refugia during the gradual desertification of much of Australia’s interior. 

The pasture dynamics and management of two rangeland communities in the Victoria River District of the Northern Territory.

1985 ◽  
Vol 7 (2) ◽  
pp. 107 ◽  
Author(s):  
BD Foran ◽  
G Bastin ◽  
B Hill
Keyword(s):  
Calcareous Soil ◽  
Management Strategies ◽  
Good Condition ◽  
Similarity Measures ◽  
Northern Territory ◽  
Forage Grass ◽  
Pasture Management ◽  
North West ◽  
Standing Biomass ◽  
Semi Arid

The use of destocking as a means of promoting pasture recovery was evaluated on two important rangeland types of the semi-arid tropics of north west Australia. Recovery on eroded calcareous red soils was substantial within five years. Standing biomass and species composition, particularly the contribution of the major forage grass Enneapogon spp., was then similar to areas in good condition. However, an exotic shrub, Calotropls procera, invaded the area during the study. Grazing limited its increase to 200 bushes ha-1 compared to unstocked areas where it increased to 1,000 bushes ha-1. Destocking had no effect on cracking clay soils in good condition, dominated by Chrysopogon fallax and Iseilema fragile. An index based on similarity measures of herbage standing biomass, followed closely the course of recovery of the eroded calcareous soil during the period. There is a need for range condition assessment and the development and application of appropriate pasture management strategies for the whole district.

scholarly journals Monitoring of the vegetation around artificial watering points (windmills) in the Kalahari Gemsbok National Park

Koedoe ◽  
1990 ◽  
Vol 33 (1) ◽  
Author(s):  
N. Van Rooyen ◽  
D. Bezuidenhout ◽  
G.K. Theron ◽  
J. Du P. Bothma
Keyword(s):  
Plant Species ◽  
National Park ◽  
Vegetation Changes ◽  
Basal Cover ◽  
Average Rainfall ◽  
Artificial Watering

Vegetation changes around artificial watering points were monitored in the Kalahari Gemsbok National Park from 1978 to 1989. Both rainfall and grazing influenced the vegetation but rainfall appeared to be the more significant factor. The above-average rainfall during the years preceding 1978 contributed to a relatively high basal cover in 1978. Since 1978, however, below-average rainfall was recorded resulting in a decline in basal cover, presence, frequency and density of most of the plant species. It seems likely that a wet cycle commenced in 1988, which is reflected in higher rainfall and an increase in basal cover, presence, and density. Some species maintained a relatively constant presence, some increased, and some declined during the study period. The monitoring is being continued.

Composition, leaf area index and standing biomass of eucalypt open forests near Darwin in the Northern Territory, Australia

2000 ◽  
Vol 48 (5) ◽  
pp. 629 ◽  
Author(s):  
A. P. O'Grady ◽  
X. Chen ◽  
D. Eamus ◽  
L. B. Hutley
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Carbon Balance ◽  
Stand Structure ◽  
Northern Territory ◽  
Northern Australia ◽  
Wet Season ◽  
Area Index ◽  
Standing Biomass ◽  
Open Forests

Savanna communities dominate the wet–dry tropical regions of the world and are an important community type in monsoonal northern Australia. As such they have a significant impact on the water and carbon balance of this region. Above the 1200-mm isohyet, savanna’s are dominated by Eucalyptus miniata–E. tetrodonta open forests. We have described in detail the composition and structure as well as seasonal patterns of leaf area index and above-ground biomass in the E. miniata–E. tetrodonta open forests of the Gunn Point region near Darwin in the Northern Territory of Australia. In all, 29 tree species from four phenological guilds were recorded in these forests. Stand structure suggests that the forests were still recovering from the impacts of cyclone Tracy and subsequent frequent fires. Eucalyptus miniata and E. tetrodonta were significant contributors to overstorey leaf area index and standing biomass (>70%), and both leaf area index and biomass were strongly correlated to basal area. Leaf area index was at a maximum (about 1.0) at the end of the wet season and declined over the dry season by about 30–40%. There were proportionally greater changes in the understorey reflecting the greater contribution of deciduous and semi-deciduous species in this strata. Standing biomass was about 55 t ha –1 . Detailed descriptions of leaf area index and biomass are important inputs into the development of a water and carbon balance for the savanna’s of northern Australia.

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