Mungo National Park Flora and Kangaroo Grazing Monitoring Program

MUNGONATIONAL PARK

FLORA AND KANGAROO

GRAZING MONITORING

PROGRAM

Ray Dayman

NSWNational Parks and Wildlife Service

Lower Darling District

May 1999

CONTENTS

Page

1. Understanding the problem 1,2

2. MungoNational Park flora monitoring 2

3. Flora monitoring - contract brief 2,3,4

4. Contract brief - Costings 4

5. MungoNational Park grazing exclosures - Project format 4,5

6. Exclosure design and materials 5

7. Exclosure costings 6

8. MungoNational Park kangaroo monitoring program 6

9. Discussion 6,7

11. References 7

MUNGO NATIONAL PARK FLORA AND KANGAROO GRAZING MONITORING PROGRAM

Understanding the problem.

The overriding influence upon vegetation recovery appears from past studies in NSW and VIC appears to be climate related. Low and often unpredictable rainfall combined with high evapotransporation during summer are characteristic of the semi-arid landscape of western NSW. While rainfall is obviously crucial in promoting healthy vegetation, the level of grazing pressure which is exerted on vegetation classes and species also plays a large role in the health or otherwise of many of the semi-arid vegetation communities. Climate, grazing pressure and vegetation recovery are interrelated and interdependent, with grazing pressure the only variable open to manipulation by land managers. It is therefore crucial that grazing pressure is maintained at a level that allows for natural regeneration following the infrequent rainfall events that typify the semi-arid region.

MungoNational Park contains 3 main grazing animals which are known to impact on semi-arid environments:

(1) Rabbits. In recent years rabbit numbers have decreased significantly due in part to near drought conditions but primarily the introduction of the calicivirus. In fact since 1997 it has become unusual to see a rabbit in many areas of the park. Ongoing rabbit eradication works are continuing. Rabbit grazing pressure is clearly at its lowest level since the introduction and effect of myxomatosis decades ago.

(2) Feral goats have in previous years been fairly common within the park and have caused substantial damage in areas, especially adjacent to water sources. In recent years the effect of contract musterers within the park and the relatively high demand and prices for goats have led to a reduction in overall numbers across large areas of western NSW. Goats appear at present to contribute little to total grazing pressure (TGP) within MungoNational Park.

(3) Kangaroos (primarily Western Grey and Red) are numerous throughout the park and adjoining pastoral properties. This is due to a number of factors including, the provision of artificial watering points, the removal of stock and in recent years other grazers and the fact that kangaroo harvesting does not occur on park.

Studies conducted in north-west Victoria have shown that during times of good rains and initially low kangaroo numbers, there is likely to be a flush of good pasture growth and an abundance of feed followed by a corresponding increase in kangaroo numbers through improved breeding conditions. Kangaroo numbers will rise relatively quickly to a level which is high enough for the amount of previously abundant feed to run short. This appears to be the critical time for land managers. High kangaroo densities and shortages of preferred feed lead to a switch in diet (usually from grass/pasture to woody perennials). Studies by Coulson and Norbury 1988 have shown that this diet switch is likely to occur if grass forage biomass falls below 400kg DW/ha. Kangaroos may be able to survive for some time on this non-preferred diet in the presence of available ground water, usually ground tanks, some of which may hold water for 12 months or more. As a result, the biomass of palatable plants species is almost certain to decrease severely. Species such as Needlewood Hakea leucoptera, Belah Casuarina pauper, Rosewood Alectryon oliefolius var. canescens, and various Callitris species may be prevented from regenerating altogether.

In the event of prolonged drought conditions, kangaroos are often themselves in poor condition and eventually die in significant numbers with densities again falling to lower levels. The sequence of events described above is likely to recur. The end result over time being severe loss of regeneration of palatable plant species.

In addressing this scenario which appears to be occurring within Mungo National Park, Mallee Cliffs National Park within Lower Darling District and probably other parks and reserves within the Western Region a number of questions remain at present unanswered or with little information available. A few of these questions are:

How many kangaroos are presently on the park and in which vegetation types are the highest concentrations found?

Which grazing animals are having the most effect on vegetation types?

If kangaroo grazing is the potentially severe as thought what effect is this having on various vegetation types? Particularly in regard to species recruitment, species biomass and growth rates.

Would the present situation improve if there was negligible grazing pressure? Or is the state of some vegetation types so degraded already that direct intervention is the only solution.

MUNGO NATIONAL PARK FLORA MONITORING

A crucial component of any grazing impact study is obviously extensive flora monitoring in order to ascertain the impact that grazing animals have on selected vegetation types. Flora monitoring may take many forms depending on the level of information required, the availability of staff/contractors and financial constraints. Within Mungo National Park 3 major vegetation types were identified as being likely to suffer extensive damage from grazing pressure. These were belah woodland, pine woodland and bluebush shrubland.

It is particularly important to measure the grazing impact on 2 major levels, biomass and floristics.

In order to monitor biomass effectively it is necessary to establish a substantial number of monitoring sites. In Mungo National Park 400 square metre quadrats will be established along designated transect lines. Transect lines should traverse all the nominated vegetation types if possible and will be monitored using the modified DWR method as described in Sluiter 1995. In addition 15 (5 in each nominated vegetation type) quadrats will be established for use as standard photographic sets which will enable the determination of comparative yield.

Grazing exclosures will also be comprehensively monitored. All woody perennials will be plotted on an excel spreadsheet and overtime this will provide valuable data on the effects of grazing pressure.

MUNGONATIONAL PARK KANGAROO GRAZING MONITORING PROJECT

CONTRACT BRIEF - DRAFT VERSION ONLY

Aim of study

To establish a baseline vegetation monitoring program which will enable NPWS to effectively monitor vegetation changes relating to kangaroo grazing pressure in 3 major habitat types within Mungo National Park (MNP).

Identify and quantify the effect of kangaroo grazing pressure on 3 major vegetation communities within MNP.

Objectives of study

1) Assess current vegetation condition.

2) Identify current kangaroo grazing levels within vegetation communities within MNP.

3) Identify strategies required to promote vegetation “health” within MNP.

4) Identify prospects and incidence for the regeneration of woody perennial species within MNP.

SERVICES

General

To identify representative transect and site locations within belah woodland (1b), Pine Woodland (1c) and bluebush shrubland (4b) vegetation communities within MungoNational Park as per classifications contained in Westbrooke and Miller, Vegetation of Mungo National Park.

To establish and implement monitoring program of biomass and floristics within MungoNational Park with respect to the major vegetation types listed above in accordance with methods as described in Sluiter 1995. To collect and analise baseline data during contract period and provide a written report on the results of initial sampling.

Particular

Contractor to:

1) Identify major vegetation types ( belah woodland, pine woodland, bluebush shrubland) and potential representative sampling transects/sites within MungoNational Park. Submit proposed methodology to DM - Lower Darling District for appraisal.

2) Install and collect baseline biomass and floristic field data from permanent monitoring sites (sq. m quadrats) along transect lines comprising approx. 400 quadrats using the modified DWR method as described in Sluiter 1995. All transects should include all nominated vegetation types if possible. The Service will supply permanent marker stakes and numbered tags.

Data to be provided in excel format.

3) Establish (approx. 15 - 5 in each identified habitat) standard photographic sets for the determination of comparative yield as described in Sluiter 1995.

4) Undertake collection of biomass and floristic field data entailing the examination of 24 25m by 50m exclusion plots.

5) Draft report to be submitted to District Manager - Lower Darling within 60 days of completion of field sampling. Supply to the satisfaction of the District Manager, Lower Darling 5 bound copies of the final report containing results and analysis at the conclusion of the project. Reports to be tendered within 120 days of completion of field sampling.

6) Analysis as follows:

a) plot monocotyledon and dicotyledon biomass for; belah woodland, pine woodland and bluebush shrubland vegetation types.

b) plot biomass of introduced weeds, native perennial grasses and other monocotyledons.

c) plot the location of woody perennial species and any regeneration on excel chart for each 25m by 50m exclusion plot.

d) for each sq.m quadrat record comparative yield, total ground flora biomass, monocotyledon biomass, dicotyledon biomass, identification of each plant (species level) found within the quadrat and respective contribution to total biomass.

e) supply total species list of all species recorded in excel format

f) identify presence/abundance/location of schedule 1 and 2 species.

g) identify management strategies required to promote vegetation/habitat recovery within MNP.

7) Supply collected biomass and floristic data on computer disc in Excel spread sheet format

Progress payment details -

1st payment - 50% payment will be made after completion of field sampling

2nd payment - 40% payment will be made on receipt draft report.

3rd payment - 10% on receipt of final report.

Report requirements - Final report should reflect the following outline.

Summary: Summary of findings and analysis

Introduction: Scope and objectives of project

Study area: Description and maps showing location of all transects/monitoring

sites

Methods: Schedule of dates on which surveys were employed. Summary of

sampling methods employed.

Results: Overview of significant results, including plots of biomass by

vegetation type and description of floristics for each vegetation type.

Discussion: Interpretation of results including comparison of communities

in respect of grazing pressure, condition of habitat types,

identify/quantify presence of indicator (increaser/decreaser) species,

presence/absence of schedule 1/2 species, identify trends in

vegetation communities, comment on the incidence and prospects for

future regeneration for woody perennial vegetation and sch. 1 and 2

species inparticular.

Recommendations: Supplementary data which may be useful in enhancing further

monitoring. Improvements which could be made to current methods.

Recommendations for future monitoring.

Appendices: Listing of all biomass, floristic and structural data in Excel format.

Special conditions

1) All plant names to correspond with Harden G.J.(ed) Flora of NSW (1990 - 1993)

2) Species to be identified to species level except where there is insufficient fertile material to allow this to be achieved.

3) Off-road use of vehicles is not permitted. Line transects must be walked in the course of data collection.

4) The contractor shall provide the District Manager - Lower Darling with a schedule of field visits.

5) The contractor shall allow NPWS staff to accompany him/her on occasions for the purposes of obtaining field sampling experience.

6) Study methodology and vegetation monitoring site locations must be submitted to the District Manager - Lower Darling for approval prior to field work commencing.

7) Final report to be submitted by-----.

CONTRACT BRIEF - COSTINGS

The costs associated with implementing the contract brief described above would be approx. $30.000.00 in the initial establishment year and $ 20.000.00 thereafter. The cost of the contract can obviously be lessened by deleting elements of the brief. Monitoring of floristics takes considerable time and therefore money so another option is to only monitor biomass within the 400 sq. metre quadrats or to decrease the number of quadrats substantially. Biomass monitoring only of the 400 sq. metre quadrats would decrease costs to approx. $20.000.00 in the initial establishment year. (likely costings provided by Ogyris Ecological Research)

MUNGONATIONAL PARK GRAZING EXCLOSUES - PROJECT FORMAT.

In order to effectively monitor grazing pressure within MungoNational park the establishment of grazing exclosures in selected habitat types will be necessary. Vegetation types targeted will comprise belah woodland, pine woodland and bluebush shrubland as these vegetation types are believed to be subjected to high levels of grazing pressure, generally low levels of seedling recruitment, and decreasing vegetative biomass.

Grazing exclosures will take the form of 24 25m by 50m exclosures. Each vegetation type will contain 2 “sampling sites”.

Each sampling site will comprise 4 separate exclosures as outlined below:

- exclude kangaroos but allow entry to rabbits

- exclude rabbits and goats but allow entry to kangaroos

- exclude all grazing animals

- exclude nothing (control)

Each exclosure within a “sampling site” will be located in similar vegetation communities, aligned in the same direction and be as close as possible to the same elevation and aspect. It is anticipated that exclosures will need to be situated relatively close together to avoid differences in climatic conditions but not so close as to bias the data obtained. i.e. the effect of animals entering one exclosure should not influence other exclosures, therefore a distance of 100 metres should be left between all exclosures.

Monitoring of individual exclosures will provide data relating to the effect of the major grazing animals (rabbits/goats and kangaroos) on vegetation types down to species level in most cases. The monitoring of exclosures combined with other flora monitoring as outlined in the contract brief will provide the data and over time the information required for sound decision making in regard to pest control and other associated management programs

EXCLOSURE DESIGNAND MATERIALS

EXCLOSURE COSTINGS

The costs in materials for the 24 exclosures as discussed above is $12.500.00 (Elders quote,April 1999). This does not include costs associated with erection of exclosures which if contracted to a private company would be approx. $4000.00

MUNGONATIONAL PARK KANGAROO MONITORING PROGRAM

The monitoring of kangaroo densities is a key component in assessing the role and effect that kangaroos may have on particular areas and vegetation types within MungoNational Park. Numerous methods are available for estimating kangaroo densities including aerial survey (fixed wing and helicopter), ground surveys (walking and driving), scat counts within quadrats and computer modeling according to rainfall.

Due to the relatively small area of Mungo National Park, walked line transects appear to be the most appropriate method for determining densities taking in to account availability of staff and volunteers, financial outlay required and this techniques proven reliability. Estimating kangaroo densities through computer modelling according to rainfall events also shows great promise and should be further investigated as funds allow. This technique could prove extremely valuable as it may provide advance estimates of densities which can then be more easily managed if necessary.

The measuring technique to be utilised will be similar to that implemented in S.A. and Victoria and will involve 1 person walking a designated transect line.

Analysis of data can be organised through the Manager - Kangaroo Management Program at relatively little cost to districts.

Information that is required in order to estimate densities is listed below:

Species of kangaroo (break down into male/female and age class, juvenile/sub-adult/adult)

Distance to animal or group of animals

Compass bearing to animal

Vegetation type and distance from start point

Other information that should be included on data sheets:

start/finish time

participants name

other species sighted such as goats, emus, rabbits, pigs

weather conditions such as temperature, cloud cover, wind speed/direction

transect number

date

location

The transect method accuracy is dependent on several factors. These factors are that no animals on the transect line are missed, individuals are detected at their original position and that all distances to the transect are accurately measured.

DISCUSSION

The major constraint in establishing a grazing monitoring project such as outlined above is the cost associated with its establishment and implementation. The methodology would not require substantial modification but obviously with access to more money, the project could be expanded in a number of ways which would provide more data and therefore a higher degree of certainty in drawing conclusions. The major areas that would provide benefit from expansion would include:

inclusion of other vegetation types in analysis
expansion in the number of floristic quadrats
the inclusion of more replicate grazing exclosures (the minimum number of replicates is usually considered to be 3)
increase the size of grazing exclosures, 25m by 50m is considered by many to be on the small side especially in relation to large species communities.
inclusion of a grazing exclosure which allows entry to rabbits only
inclusion of rainfall gauges at each grazing exclosure sampling site
surveying (via walking transects) larger percentages of park/reserve for kangaroos.

REFERENCES

Arundel, J.H. Lee, A.K, Middleton, D.R, Rawlinson, P.A, and Wooley, P.A. 1990, Report on Techniques for Controlling Kangaroo Populations. Department of Conservation and Environment, Victoria.

CONCOM, 1985, Code of Practice for the Humane Shooting of Kangaroos, Australian national Parks and Wildlife Service, Canberra.

Coulson, G. and Norbury, G. 1988, Ecology and Management of Western Grey Kangaroos (Macropus fuliginosus) at Hattah-KulkyneNational Park. Arthur Rylah Institute for Environmental Research, Technical Report Series No. 72.

Department of Conservation and Environment, 1990, Restoring the Balance, A Kangaroo Control Program for the Hattah-Kulkyne National Park, Department of Conservation and Environment, Victoria.