Prepared by Officials to Support the West Victoria Regional Forest Agreement Process

WEST VICTORIA

Comprehensive Regional

ASSESSMENT REPORT

(VOLUME 2)

October 1999

Prepared by officials to support the West Victoria Regional Forest Agreement Process

Published by the joint Commonwealth and Victorian Regional Forest Agreement (RFA) Steering Committee.

© Commonwealth of Australia 1999

The views expressed in this report are those of the authors and not necessarily those of the Commonwealth of Australia or Victoria. The Commonwealth and Victoria do not accept responsibility for any advice or information in relation to this material.

Copies are available from:

Department of Natural Resources and Environment

Address:8 Nicholson Street

EAST MELBOURNE Vic. 3002

Tel:(03) 9637 8080

Copies will also be available through the Environmental Resources Information Network on its World Wide Web Server. Contact:

For further information about this report, contact the Commonwealth Forests Taskforce

Tel:1800 650 983.

This work is copyright. It may be produced in whole or in part for study or training purposes subject to the inclusion of acknowledgment of the source and no commercial usage or sale. Reproduction for purposes other than those listed above requires written permission from the Commonwealth and Victorian RFA Steering Committee.

Requests should be addressed to:

Commonwealth and Victorian RFA Steering Committee

C/- Commonwealth Forests Taskforce

Department of the Prime Minister and Cabinet

3-5 National Circuit

BARTON ACT 2600

Tel:1800 650 983

ISBN No: 0 642 76004 7

FOREWORD

This report describes those components of the detailed Comprehensive Regional Assessment (CRA) that have been undertaken in Victoria’s West Regional Forest Agreement (RFA) region in relation to:

• old growth; and
• biodiversity assessment (in particular for the Portland and Horsham regions).

Volume 1 of the Comprehensive Regional Assessment Report covered:

• biodiversity (Midlands and Otway regions);
• world heritage;
• social values;
• forest resources;
• tourism and recreation;
• streams and catchments;
• minerals;
• forest based industries; and
• ecologically sustainable forest management.

National Estate values will be covered in a separate report.

Meetings with local communities and interest groups will be held following the release of this Report and the Directions Report for the West region RFA. These consultations and assessments, along with those public meetings already held, will provide a basis for the Victorian and Commonwealth Governments to develop a Regional Forest Agreement for the West region RFA.

The RFA will define the commitments made by both Governments to forest conservation, use and development, and the development of those industries based on the forest resources of the region. The RFA will operate for 20 years.

CONTENTS

FOREWORD......

12.Biodiversity (Part 2)......

12.3Data Review for Terrestrial Species......

12.4Forest Ecosystem Assessment......

12.5Flora Species Assessment......

12.6Terrestrial Fauna Species Assessment (Cont.)......

17.OLD-GROWTH FOREST......

17.1Introduction......

17.2Assessment Methodology......

17.3Analysis of Data and Results......

REFERENCES......

Appendix 1: descriptions of ecological vegetation classes (evcs) occurring in the west victoria rfa region

INDEX......

GREATER GRAMPIANS VEGETATION DESCRIPTIONS......

LIST OF TABLES

Table 12.11: Proportion of Flora Sampling Density Classes for the West Region......

Table 12.12: Adequacy of Terrestrial Vertebrate Fauna Survey, by Species Group.....

Table 12.13: Representative Conservation (percentage reservation status) of EVCs in the West Region (Portland & Horsham FMAs) based on pre-1750s Vegetation Mapping………………………………………………………………………………… 5

Table 12.14: Representative Conservation (percentage reservation status) of EVCs in the West Region (Portland & Horsham) by FMA…………………………………...……12

Table 12.15: The National Forest Reserve (JANIS) Criteria Used to Assess the Conservation Status of EVCs

Table 12.16: Endangered, Vulnerable and Rare Ecological Vegetation Classes in the Portland and Horsham FMAs

Table 12.17: West Region Plant Species Listed (or Recommended for Listing) under the FFG Act and/or ESP Act

Table 12.18: Plant Groupings of Conservation Significance in the West Region……….23

Table 12.19: Plants Occurring in the West Region which are rated as Critically Endangered or Endangered according to the IUCN and RARE Rule Sets

Table 12.20: Tenure in the West Region of Populations of Plant Species Listed under the FFG Act and/or the ESP Act

Table 12.21: Plant Species with High Regional Priority for Management Action......

Table 17.1: Representation and Reservation of Old Growth in the West Region………41

LIST OF FIGURES

Figure 17.1: Relationship between the Typical Eucalypt Growth Stages Described by Jacobs (1955) and those Considered by the West Region Old-growth Study

LIST OF MAPS

Map 1 (Vol. 2)Ecological Vegetation Classes  Pre-1750 Extent

Map 2 (Vol. 2)Extant Ecological Vegetation Classes

Map 3 (Vol. 2)Old Growth Forest

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Chapter 12 Biodiversity

12.Biodiversity (Part 2)

The Biodiversity Chapter for the West region has been produced in two parts: Volume 1 included sections 12.1 Introduction, 12.2 Methods used in Biodiversity Assessment, 12.4 Forest Ecosystem Assessment (Midlands and Otway Forest Management Areas (FMA)), 12.6 Terrestrial Fauna Species Assessment, 12.7 Review of Disturbances and Implications For Flora and Fauna and 12.8 Aquatic Fauna Species Assessment (VicRFASC1999). The second part of the chapter follows and includes sections: 12.3 Data Review for Terrestrial Species, 12.4 Forest Ecosystem Assessment (Portland and Horsham FMAs), 12.5 Flora Species Assessment and 12.6 Terrestrial Fauna Species Assessment (Invertebrates Assessment).

The West region Directions Report will provide EVC information that combines the EVC data presented in Volume 1 and Volume 2.

12.3Data Review for Terrestrial Species

Introduction

The data review process involves systematically working through databases to determine the adequacy of information about the distribution of species within the West region. This information is important for understanding the distribution of flora and fauna and relating this to their habitat requirements. The data review relies on expert knowledge and professional judgement but is supplemented by explicit analyses where appropriate. The methods described here were used for terrestrial flora and fauna only - the data review for aquatic species was included in section 12.8 of Volume 1.

The first step in the process is to select only those survey data which meet required standards of accuracy, precision and reliability. This allows a degree of confidence when analysing the distribution of species.

The next step involves assessing the extent to which the site records for flora and fauna are representative samples of the environmental and geographic variation of the region. This is achieved by dividing the region into units or ‘strata’ which exhibit similar sets of environmental factors or variables. Although there are many variables to choose from (e.g. temperature, rainfall, elevation, slope), those which are considered to most influence the distribution of species in that region are selected to create the stratification. Each stratum may be represented by several discrete areas (or substrata) within a region.

These strata and substrata are then analysed to determine how well each has been surveyed for flora and fauna. That is, the density of survey sites is determined for each (such as number of survey sites per 10000 hectares). Calculations are also made for each stratum of the probability of encountering species that have not previously been recorded in surveys there.

Methods

Analyses of the variation in annual rainfall, temperature extremes and rock types across the region were used to classify the major types of environments occurring in the West region. The classification analysis identified 86 different strata for the region, each characterised by a particular combination of rainfall, temperature and rock type. They ranged in size from 3 to 96 470 ha. It is important to note that only forested areas were considered. Twenty three of the 86 strata had an area of less than 500 ha each. These small strata comprised only 0.3percent of the area under forest cover, and were not evaluated while the 27 largest strata (>10000 ha) occupied 87percent of the forested land area. This environmental stratification was subsequently used for the analyses of flora and fauna databases presented below.

Flora

The dataset used for the assessment of the West flora was derived from the Flora Information System of Victoria. It comprises all available data from vegetation surveys and studies of the region and includes 5515 site records, of which 3540 are on forested land.

The distribution and density of site records (summarised in Table 12.11), together with cumulative species curve analysis (probability that the next species encountered for a stratum would not already have been encountered), were used to evaluate the adequacy of sampling of the environmental variation in the region.

Table 12.11: Proportion of Flora Sampling Density Classes for the West Region

The majority of forested land in the West region (53 per cent) has a moderate survey intensity with 21 and 25 per cent of the region having a high and low survey intensity respectively. The results from a cumulative species curve analysis suggests an adequate data coverage, with 89percent (39 strata) of the forested area of the region having probabilities of 20percent that the next species will be new.

Fauna

In Victoria, much of the existing site data for fauna has come from incidental records from a range of sources supplemented by information from systematic surveys. A lack of surveyed sites in certain strata does not necessarily mean that the strata have not been sampled; rather, it means that the information may not have been appropriate for use in this analysis. To ensure an adequate database of systematic survey records for terrestrial fauna, a general survey covering 122 sites was undertaken in the West region and used to supplement the existing data sets. This data audit includes only data from formal surveys and strata under forest cover.

The site-based biological data sets used in the fauna assessment were drawn from the Atlas of Victorian Wildlife. A number of groups were excluded from the study including marine birds, waders (except Latham’s Snipe), marine mammals, marine reptiles and invertebrate fauna; records with less geographic precision were also excluded. Survey data were analysed for each of the species groups indicated in Table12.12.

As was done for flora, the distribution and density of survey site records were used to evaluate the adequacy of sampling of the environmental variation in the region. The 63 strata larger than 500 ha were included in the evaluation. Strata and large polygons with low densities of sites were identified. The probability of the next species recorded for a particular stratum being new (i.e. not previously recorded in surveys for that fauna group in that stratum) was used as an indication of the adequacy of sampling effort. The analysis was mostly confined to the 27 most extensive strata, which range from 8 percent to 0.84percent of the area (totalling 87percent of the forested area). A summary of results for these strata is given in Table 12.12.

Of the 27 largest strata generated by the stratification of the West region, the majority contained survey sites for each of the fauna groups considered. Diurnal birds are the most comprehensively surveyed groups across the region, based on them having the most strata with low probabilities of new species being detected (Table 12.12). Arboreal mammals, bats and large forest owls have also been well surveyed with between 65-70 per cent of the surveyed large strata having a low probability of detecting new species with further survey. Additional surveys for amphibians are most likely to detect species not previously recorded in surveys.

Table 12.12: Adequacy of Terrestrial Vertebrate Fauna Survey, by Species Group

12.4Forest ecosystem assessment

Introduction

Assessment of forest ecosystems is important to determine whether representative examples of these ecosystems and the natural ecological processes that support them are maintained throughout their natural range. The assessment of forest ecosystems has involved describing, mapping and analysing the distribution and variation of these ecosystems in the region. Due to the size of the region and complexity of the task, the vegetation assessment has been conducted in two parts. One part deals with the sub-region consisting of the Portland and Horsham FMAs, and for which the survey results are presented in this volume, and the other covers the Midlands and Otway Forest Management Areas (FMAs), and is reported in Volume One (VicRFASC 1999). The two parts will subsequently be merged for the purposes of developing a regionwide perspective on ecosystem representation.

Ecological vegetation classes (EVCs) are the basic mapping units used for biodiversity planning and conservation assessment at landscape, regional and broader scales in Victoria. They are derived from large-scale forest type and plant community mapping and are based on the following types of information:

• plant communities and forest types (including species and structural information);
• ecological information relevant to the species that comprise the communities (including life form and reproductive strategies); and
• information that describes variation in the physical environment (including aspect, elevation, geology and soils, landform, rainfall, salinity and climatic zones).

Each EVC represents one or more plant communities that occur in similar types of environments. The communities in each EVC tend to show similar ecological responses to environmental factors such as disturbance (e.g. wildfire). As well as representing plant communities, the EVCs can be used as a guide to the distribution of individual species and groups of species, including animals, and lower plants such as mosses and liverworts.

Ecological Vegetation Classes have been accepted as robust and appropriate units for assessing forest ecosystem diversity and conservation at the landscape scale, provided that the variability within widely distributed EVCs is also considered as part of the assessment (Comprehensive Regional Assessment, East Gippsland: Environment and Heritage Report  ref VicRFASC 1996). A detailed description of the EVC concept can also be found in that report.

A total of 355 EVC unitshave been identified as currently occurring in the Portland and Horsham FMAs. These EVCs have been mapped across all land in the region at a scale of 1:100 000 and are listed in Table 12.13. A description of each EVC is available in Appendix 1. It should be noted that approximately 70 per cent of the EVCs in the Portland and Horsham FMAs are described as mosaics or complexes (see Table 12.13 footnotes for definitions). For the purposes of this report and analysis of representation, 187 of the smallest mosaics and complexes have been grouped. These units are generally too small to be represented on maps and have been determined not to contribute to the vulnerability of their component EVCs. These units are typically less than 50 ha and most are located in permanent reserves (principally the Grampians National Park).

To allow a comparison of the current distribution of each EVC with its approximate distribution prior to European settlement, a map of the pre-1750 distribution of EVCs has been constructed (see Map 1, Vol. 2). The map is based on predictions derived from existing vegetation, a variety of physical environmental attributes, and expert knowledge.

EVCs that were not recorded in the public land vegetation mapping of the region are primarily confined to fertile soils which have been largely cleared for agriculture.

Reservation Status of Ecological Vegetation Classes

A reserve system that is comprehensive, adequate and representative in its regional coverage of forest ecosystems is an important component of the Regional Forest Agreement for the West region. The extent of representation of EVCs in conservation reserves has been used as the basis for evaluating the current reservation status of forest ecosystems in the region.

Table 12.13 shows the distribution of EVCs across all land tenures in the Portland and Horsham FMAs. Descriptions of some of the land tenure categories represented in the table are as follows:

Conservation: includes all dedicated National and State parks and other conservation reserves such as flora and fauna reserves, Regional Parks where timber harvesting does not occur and Heritage Rivers.

Other Parks and Reserves: includes historic and cultural features reserves, where timber harvesting may be permitted.

Other Public Land: includes land managed by Government agencies, such as water supply authorities.

Private Land: includes freehold land and plantations licensed to Hancock Victorian Plantations.

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