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Rural Industries
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Project Title
The impact of trees on the physical environment and productivity of farmlands
Objectives
Field measurements ended in 1997 after 4 years of data collection. 1998 will be spent writing up the results for inclusion in planned journal special edition. All relevant data sets have been passed on to APSRU and CSIRO.
Crop measurements in the lee of 60 field windbreaks have shown microclimate modification can improve yields in dry years. High levels of shelter improved crop water use efficiency and gave large yield increases in years with average or below average rainfall. At sites which have suffered wind erosion, windbreaks protected crops for 20 to 30 times their height and gave very big savings to farmers. Economic modelling has shown the profitability of windbreaks in WA depends on crop species, the degree of competition between the trees and crop and the frequency and severity of wind erosion events.
Preliminary work has shown competition can be virtually eliminated where tree roots are concentrated near the surface and can be root pruned. Where they are not concentrated near the surface root pruning is of little value. Further work is needed to characterise the root morphology of tree species growing on different soil types and the effect of competition management on crop and tree growth.
RIRDC Project No: DAW-49A
Start Date: 2 January, 1994
Finish Date: 21 December, 1998
Researcher: Dr. Ed Barrett-Lennard
Organisation: Agriculture Western Australia, Resource Management, Locked Bag No 4, BENTLEY DELIVERY CENTRE WA 6983
Contacts: Phone:
(08) 9368 3278 Fax:
(08) 9368 3355
E-mail: eblennard@agric.wa.gov.au
Investigating the conservation characteristics of native trees on agricultural land
Objectives
In the last 18 months, a number of components have been completed. A survey of landholders and land managers in the SW Slopes, NSW was undertaken in February-March 1997 to investigate perceptions of and attitudes towards various vegetation management issues (eg. Remnant vegetation protection, revegetation, clearing, shrub planting etc.). A report on this survey is now available.
Bird surveys were completed in June 1997. This data is currently being analysed. Preliminary findings indicate that remnant vegetation on rural land provides a relatively simplified habitat for woodland birds, characterised by lack of shrub understorey and reduced plant species richness. These small remnant patches tend to have fewer bird species occupying them than more complex, less disturbed habitat in nearby state forests and nature reserves.
RIRDC Project No: ANU-20A
Start Date: 1 May, 1994
Finish Date: 30 June, 1999
Researcher: Professor Henry Nix
Organisation:
Centre for Resource and Environmental Studies, Australian National University,
ACT 0200
Contacts:
Phone: (02) 6249 4277 Fax:
(02) 6249 0757
E-mail: nix@cres.anu.edu.au
Project Title
Impact of insects on eucalypt plantations in the Murray Valley
Objectives
Current Progress
Insect damage in plantations of Eucalyptus globulus planted in 1994 and Eucalyptus grandis planted in 1993 has been monitored since planting. Trails of Eucalyptus dunnii, Eucalyptus benthamii and Eucalyptus maculata, planted in 1995 at Deniliquin have been monitored for damage since 1996. Collection of data to determine phenology of major insect pests has also occurred over the same time period. The most important foliage feeding insect pests have been identified as Mnesampela privata (autumn gum moth), Cardiaspina fiscella (brown basket lerp), Phylacteophaga spp. (leafblister sawfly) and Anoplognathus spp. (Christmas beetle). Patterns of resistance and growth at a provenance and family level are currently being analysed for data from the Eucalyptus globulus and Eucalyptus grandis trials. Provenances with resistance to insect attack and with the greatest growth potential have been identified. Analysis of the Eucalyptus globulus data is the most complete and has demonstrated cross-resistance to insect attack at the provenance level. Provenances that are resistant to Christmas beetle attack have also show resistance to leafblister sawfly and autumn gum moth. Also it was found that there was a negative relationship between Christmas beetle attack and subsequent growth rates.
RIRDC Project No: CSE-72A
Start Date: 1 July, 1995
Finish Date: 30 June, 2000
Researcher: Dr. Robert Floyd
Organisation: CSIRO Entomology, GPO Box 1700, CANBERRA ACT 2601
Contacts: Phone:
(02) 6246 4089 Fax:
(02) 6246 4155
E-mail: R.Floyd@ento.csiro.au
Identification of pest resistant eucalypts using near infrared spectroscopy
Objectives
During the past year, we have met the first two milestones. The near-infrared reflectance spectrometer (NIRS) was successfully installed, and it is currently fully operational. We identified trees of four species of Eucalyptus with high and low concentrations of 1,8-cineole and sideroxylonal, which had been hypothesised to correlate with resistance. We have conducted feeding trials with marsupial herbivores and Christmas beetles using those trees identified. Trees with high concentrations of 1,8-cineole and sideroxylonal supported lower leaf consumption by both marsupial herbivores and Christmas beetles than trees with low concentrations of 1,8-cineole and sideroxylonal. We are currently developing calibration equations of NIRS to predict (1) concentrations of 1,8-cineole and sideroxylonal and (2) food intake by marsupial vertebrates based on NIRS spectra. We will be validating NIRS predictions of food intake by conducting feeding experiments using marsupial herbivores.
RIRDC Project No: CSE-78A
Start Date: 1 January, 1997
Finish Date: 31 December, 1999
Researcher: Dr. Robert Floyd
Organisation: CSIRO Entomology, GPO Box 1700, CANBERRA ACT 2601
Contacts: Phone:
(02) 6246 4089 Fax:
(02) 6246 4155
E-mail: R.Floyd@ento.csiro.au
Project Title
The impact of trees on winds, temperature and evaporation rates in farmlands
Objectives
Our research has focussed upon, and almost completed, the following activities:
Start Date: 1 July, 1993
Finish Date: 30 April, 1999
Researcher: Dr. Helen Cleugh
Organisation: CSIRO Land and Water, GPO Box 1666, CANBERRA ACT 2601
Contacts: Phone:
(02) 6246 5574 Fax:
(02) 6246 5560
E-mail: helen.cleugh@cbr.clw.csiro.au
Project Title
Agroforestry design guidelines to balance catchment health with primary production
Objectives
Tree water use under optimal conditions
The experimental plantation of Eucalyptus grandis at Wagga Wagga has been irrigated since planting with sewage effluent. Four levels of thinning (650, 500, 350 and 200 stems/ha) were applied to replicate plots during June and July 1997; tree height and canopy volume of 80 sample trees were measured in August before the spring growth flush commenced and 10 trees were harvested for biomass analysis. Tree water use has been measured on 2 - 5 trees in three treatments (650, 350 and 200 stems/ha) for 3 months prior to thinning and since thinning. Diameter growth response has been largest in the lowest stocked stands and least in the highest stocked stands during every month since thinning. Since September, the average increment in the plots with 200 stems/ha has been more than 2.5 mm per month. Total water use per plot did not change in proportion to stem populations; there are indications that increased evaporation from soil and increased direct evaporative loss during irrigation largely compensated for the reduced tree transpiration in the more open plots.
Review and measure tree water use under stressed conditions
A series of review papers has been produced, covering tree water use and water use efficiency (dry mass produced per unit water transpired), the question of water use per unit leaf area, and whether it differs significantly between species (there is no evidence, at the level of whole trees, that it does), tree root systems and the effects of salinity on tree growth. Four of these reviews are being published by the RIRDC/LWRRDC/FWPRDC Joint Venture Agroforestry Program. It is becoming possible to model, with useful accuracy, the effects of water stress (drought) on tree growth and productivity.
Measurements of tree growth and water use under stressed (saline) conditions are being made on experimental plantings in the Wellington district. Preliminary results from this work (and work reviewed) are beginning to provide the data needed to determine the effects on tree growth of particular levels of salinity, although the highly variable distribution of salt in the soil and the variations in salt concentrations with the amount of water in the soil, make it difficulty to determine these effects with any precision.
Detailed laboratory experiments with trees in cylinders, with precise control of water table depth and salinity, are providing valuable information on the capacity of trees to absorb water from above saline water tables, and on the effects of the salt on tree growth.
Measure and predict the competition between trees and crops for water in different agroforestry systems
Measurements of the water use of trees (Tagasaste) and cereals in an alley-cropping system in Western Australia are proceeding. The growth of the Tagasaste and the cereals is also monitored.
A model (called AGFOR) has been developed to simulate tree and pasture growth under conditions where their root systems compete for water. The model provides the opportunity to examine various root systems and arrangements. It has yet to be thoroughly tested.
Catchment model scenarios
A control program called SCENARIO has been developed for the catchment model TOPOG. Using this program TOPOG can be set up for a catchment with specified topography and soils, vegetation and climate data can be varied to produce a range of scenarios. The system runs TOPOG for these scenarios and collates the output data required to analyse their implications. Software development has been completed and analyses to determine optimum systems and catchment health are currently being carried out.
Guidelines booklet
A booklet of guidelines to support land managers by providing the information they need to help them develop optimum tree/crop/pasture systems has been drafted and the authorship and content of the various sections and chapters agreed. At meeting in July the project team will present their drafts of the booklet contents It is intended that writing work will be completed early in 1999; it will be published later in the year. This booklet will contain, in simple form, all the information obtained from the various aspects of this agroforestry project, and constitutes the major practical product.
RIRDC Project No: CSM-4A
Start Date: 1 July, 1996
Finish Date: 30 June, 1999
Researcher: Dr. Rob Vertessy
Organisation: CSIRO Land and Water, GPO Box 1666, CANBERRA ACT 2601
Contacts: Phone:
(02) 6246 5790 Fax:
(02) 6246 5845
E-mail: rav@cbr.dwr.csiro.au
Project Title
The silvicultural basis for farm forestry in Australia - a national, collaborative review of past and present silvicultural research and proposals for a national network of strategic experiments
Objectives
A national database for farm forestry silviculture (SILVDAT) has been designed, using Microsoft ACCESS. The database will hold data from published and unpublished research trials on silviculture of Australian native species, plus some data from agroforestry trials. SILVDAT stores site and experiment description information, and tree growth data is represented by treatment means and standard errors at each measurement date. The data will be analysed to look for general responses to silvicultural treatments, and whether some responses differ between regions and species. The database is designed to include a minimum data set compatible with CSIRO’s TREEDAT and Victoria’s farm forestry database.
Data entry into the database has commenced. Initially, this has concentrated on published literature and unpublished experiments conducted in Queensland. There are more than 200 published Australian papers on silviculture of eucalypts, hoop pine and rainforest species. Data is being obtained from relevant papers selected from this bibliography. The various forestry research organisations from around Australia have also volunteered data from approximately 150 trials, representing past and current silviculture trials and some farm forestry research trials. This data will be obtained over the next six months.
RIRDC Project No: DAQ-222A
Start Date: 1 April, 1997
Finish Date: 31 March, 2001
Researcher: Dr. Rod Keenan
Organisation: Department of Primary Industries (Qld), PO Box 1138, ATHERTON QLD 4883
Contacts: Phone:
(07) 4030 5267 Fax: (07) 4091 5211
E-mail: keenanr@dpi.qld.gov.au
Project Title
Forecasting tree growth and yield and financial returns of key agroforestry species across southern Australia
Objectives
Collation of existing growth data from high priority trials identified in Victoria and South Australia in the initial scoping study has commenced. Remeasurement in older trials will be completed during winter 1998. A University of Melbourne M.For.Sc. project investigating methodologies for modelling farm forestry species is continuing, including work on modelling stand basal area, modelling diameter distributions, and modelling diameter increment.
Independent reviews of the FARMTREE computer program have been completed. Regarding the tree growth modelling functions within FARMTREE, it was recommended that better indices of competition than stocking should be used, and that two phases of growth are recognised. Firstly, an establishment phase (and where the effects of various silvicultural treatments may be incorporated), and secondly a stand growth phase. In the stand growth phase the stand may be modelled as a whole, whereas in the stand growth phase the growth of individual trees should be modelled. The second review concluded that FARMTREE has the potential to meet an expanding requirement for yield and financial predictions to assist farm foresters. However, the software requires further development to improve its useability and the usefulness of outputs to ensure that it will be readily adopted and be competitive with other products.
RIRDC Project No: DAV-129A
Start Date: 1 April, 1997
Finish Date: 30 June, 1999
Researcher: Dr. Tom Baker
Organisation: Department of Natural Resources & Environment, Centre for Forest Tree Technology, PO Box 137, HEIDELBERG VIC 3084
Contacts: Phone: (03) 9450 8687
Mobile: 018 974 102
Fax: (03) 9450 8644
E-mail: t.baker@nre.vic.gov.au
Project Title
Assessment of the effects of shelterbelts on pasture and crop production in Victoria
Objectives
Following 3 years of research at Dookie in which excessive soil and shelterbelt variability prevented the detection of beneficial effects on crop production, research was focussed on a new site near Rutherglen in 1997. Artificial shelterbelt enclosures (10 x 10 m) were erected and maintained at a height of 1 m above a wheat crop. Measurements were made of crop, soil and meteorological factors. Throughout the season there was no significant difference in plant density, LAI, tiller number or plant biomass between crop within the shelters or in the open field. At harvest, the mean grain yield was 5.43 t/ha for crop within the shelter and 5.70 t/ha for crop in the open. In October and November, soil under the sheltered treatments was slightly wetter than soil under the treatments in the open, especially in the top 80 cm, but water stress did not occur. As would be expected in a season with little wind overall and no significant water deficit, no shelter benefits could be detected. Experimental work for this project has now concluded and the final report is being prepared.
RIRDC Project No: DAV-69A
Start Date: 1 July, 1993
Finish Date: 30 June, 1998
Researcher: Dr. Michael Crawford
Organisation: Department of Natural Resources & Environment, RMB 1145, RUTHERGLEN VIC 3685
Contacts: Phone: (02) 6030 4500
