Native Vegetation Condition Assessment and Monitoring Manual for Western Australia

Native Vegetation Condition Assessment and Monitoring Manual for Western Australia Prepared by: N. Casson, S. Downes, and A. Harris Prepared for: The Native Vegetation Integrity Project 2009 This project is funded by the Australian Government and the Government of Western Australia CONTENTS ACKNOWLEDGEMENTS PURPOSE AND SCOPE 1) INTRODUCTION 1.1) MAINTENANCE OF VEGETATION - “TYPES OF” CHANGE 1.2) ISOLATING THE SIGNS AND SYMPTOMS OF CHANGE 1.3) A PLETHORA OF FACTORS 2) HOW TO USE THIS MANUAL 2.1) ORIENTATION AND SITE SELECTION 2.2) BASIC ASSESSMENT 2.3) STANDARD ASSESSMENT 2.4) LINKING REMOTE SENSING 2.5) QUANTITATIVE ASSESSMENT FOR VARIOUS PURPOSES 2.6) MONITORING 2.7) LIMITATIONS 2.8) USE OF TERMS 3) ORIENTATION– BACKGROUND, RECONNAISSANCE & OBSERVATION 3.1) LITERATURE-BASED APPROACH - FINDING BACKGROUND INFORMATION 3.2) FIELD APPROACH - FINDING REFERENCE POINTS 3.2.1) TIMING OF FIELDWORK 3.2.2) LOCAL RECONNAISSANCE 3.2.3) OBSERVE THAT COVER VARIES & FLUCTUATES 3.2.4) EVALUATION OF ATTRIBUTES AT REFERENCE AREAS 3.2.5) EVALUATING MORE VEGETATION TYPES 3.2.6) FRAGMENTED OR RESTRICTED VEGETATION TYPES. 3.2.7) USING REFERENCE VALUES TO SUPPORT CONDITION ASSESSMENT. 4) SITE SELECTION 4.1) AIDS TO SITE SELECTION 4.2) LOCATION WITHIN A VEGETATION UNIT 4.3) EDGE EFFECTS 5) CONDITION 5.1) SITE LAYOUT 5.2) RECORDING DATA & SCORING ATTRIBUTES 5.3) SUMMATION OF THE SCORES 5.4) PRESENTATION OF THE SCORES 5.5) ASSESSMENT WITH CONDENSED SCALES OF FEW ATTRIBUTES 5.5.1) CONDITION SCALES – THE NATIONAL “VAST” SCHEME 5.5.2) CONDITION SCALES – THE W.A. “KEIGHERY” SCHEME 5.5.3) CONDITION SCALES - AN ALTERNATE SHORT SCALE 5.5.4) CONDITION SCALES - COLOUR CODE FOR DISPLAY 5.6) ASSESSMENT WITH MORE ATTRIBUTES 5.6.1) CONDITION SCALES - A BASIC VERSION 5.6.2) CONDITION SCALES – A TYPICAL LIST OF SITE ATTRIBUTES 5.6.2.1) NOTES ON SOME UNDERLYING CONCEPTUAL MATTERS 5.6.2.2) NOTES ON RESOURCE DOCUMENTS 5.6.2.3) BACKGROUND & GUIDANCE FOR SITE ATTRIBUTES 5.6.3) BALANCING LANDSCAPE CONTEXT & VEGETATION CONDITION ATTRIBUTES 5.6.3.1) CONDITION SCALES - ADDING LANDSCAPE ATTRIBUTES 5.6.4) CONDITION SCALES - ADDING & ADJUSTING ATTRIBUTES 6) PLANT DIVERSITY 6.1) COORDINATION OF PLANT DIVERSITY & CONDITION 7) CONTEMPORARY REMOTE-SENSING ARRAY 7.1) RATIONALE – REMOTE SENSING PIXEL SIZE & ALIGNMENT 7.2) SITE LAYOUT 7.3) BASIC PROTOCOL FOR MEASURES 8) ADDING OTHER FORMS OF ASSESSMENT 8.1) THREE WAYS OF ASSESSING EACH QUADRAT 8.1.1) WHOLE QUADRAT MEASURES 8.1.2) 1 OR 2 DIAGONAL TRANSECTS 8.1.3) NESTED SUBPLOTS 8.1.4) TRENDS AND STATISTICAL ANALYSES OF TIME SERIES 8.2) LINKING AN ARRAY TO REMOTE ASSESSMENT (INCL. CONDITION) 8.2.1) RECOGNISING CHANGE 8.2.2) ESTABLISHING A SENSE OF PATTERN 8.2.3) RECOGNISING IDENTITY OF VEGETATION 9) GENERAL CONSIDERATIONS ON MONITORING & SAMPLE NUMBERS 9.1) CONSIDERATIONS THAT AFFECT THE NUMBER & LAYOUT OF SAMPLING SITES 9.1.1) CHOICE OF MONITORING OPTION 9.1.2) NUMBER OF VEGETATION UNITS BEING SAMPLED 9.1.3) THE LEVEL OF PLOT REPLICATION REQUIRED 9.2) TIMING OF SAMPLING 9.3) FREQUENCY OF SAMPLING 10) REFERENCES 11) APPENDICES APPENDIX 1: LIST OF ATTRIBUTES FOR A SHORT ASSESSMENT APPENDIX 2: AN EXTENDED LIST OF ATTRIBUTES APPENDIX 3: EXPANSION AND ADAPTATION OF THE KEIGHERY VEGETATION CONDITION SCALE & EQUIVALENTS INTO AN ARRAY OF SEPARATE ATTRIBUTES. APPENDIX 4: BUSHLAND SURVEY SHEETS FROM KEIGHERY 1994. APPENDIX 5: SOME TRIAL FIELD SHEETS APPENDIX 6: CARABAN FIELD TRIAL FINDINGS AND DATA ACKNOWLEDGEMENTS NVI Project members Nick Casson, Stephen Van Leeuwen, Susan Downes, Anne Harris, Judith Harvey, Kristen Bleby, Marc Wohling, Mark Garkaklis, Leah Firth, Sophie Moller, Keith Claymore DEC information, input and support Alan Danks, Allan Willis, Amanda Fairs, Anthea Jones, Barbara Wilson, Carolyn Harding, Chris Dunne, Christine Freegard, Cressida Wilson, David Mickle, Deborah Harding, Deon Utber, Geoff Young, Graeme Behn, Greg Durrell, Janine Kinloch, Kate Brown, Katherine Zdunic, Ken Atkins, Ken Wallace, Kevin Vear, Kim Friedman, Lisa Wright, Maria Lee, Mick Davis, Monica Hunter, Neil Gibson, Nicholas Woolfrey, Paul Cory, Paul Rampant, Paul Van Heurck, Penny Hussey, Richard Robinson, Ryan Vogwill, Sarah Barrett, Sarah Comer, Steve Appleyard, Teagan Johnston, Val English, Vanessa Clarke, Verna Tunsell, Wendy Chow, Wendy Thompson External Cindy Ong, Muriel Davies, Paul Novelly, Ray Froend, Tim Munday PURPOSE AND SCOPE This manual has vegetation condition at its core. It has regard for a number of recognisable factors that may influence vegetation condition, or the perception of vegetation condition. It also has regard for how this inevitably interacts with other, inter-related, facets of vegetation assessment, and with how they may be distilled and incorporated as required. Consequently, it is meant to be used incrementally. The extent to which the various elements are deployed will depend on the task at hand and the intent of the assessor. 1) INTRODUCTION This manual covers the establishment of quadrat-based monitoring to determine native vegetation condition. Vegetation condition is discussed in Literature Review: Vegetation Condition Assessment, Monitoring and Evaluation . 1.1) MAINTENANCE OF VEGETATION - CYCLICAL VERSUS DIRECTIONAL (OFTEN ADVERSE) CHANGE A good introduction is provided in two existing references as follows: Change is a natural feature of native vegetation. “Individual plants grow, flower and shed seed. Plants age and die, to be replaced by others, either from seed or by vegetative growth. Changes in a plant community may be cyclic or directional. Broadly speaking, natural cycles in the plant community may be maintained by recurring events such as fire or flood. After these, species already in the habitat, perhaps as soil-stored seed, are recruited and the vegetation gradually regains its former structure. Depending on the sequence of events and weather conditions, slightly different combinations of species may be favoured, but the plant community is essentially self-maintaining. Directional change may be induced by habitat disturbance which alters soil and water properties, and allows recruitment of species not native to the habitat, in particular, exotic weeds. Such changes generally lead to bushland deterioration.” (Benson and Howell 1990). The extent of the change will be dependent on the nature, extent, and duration, of the disturbance, and the associated pace of change. “Activities that adversely affect the self-maintenance of bushlands are commonly called disturbance factors. Such factors include partial clearing, fragmentation, selective removal of species (for example, timber cutting, wildflower picking, mowing), dieback, fire regime, ‘enrichment planting’ (that is planting of species not found in that plant community), weed invasion, animal impact (horses, foxes, rabbits, cats, dogs), soil movement (both removal and dumping), changes in water regimes (flooding, drainage and watering), rubbish dumping, mining (particularly mining for roadworks, grazing (stock, overgrazing by native mammals), proliferation of tracks (fire-breaks and walk trails), off-road vehicle use, use of service corridors (for electricity, gas, roads and water), fertiliser drift and pesticide or nutrient influx along waterways.” “Not all of these factors have the same level of impact but generally they are interrelated, the presence of one type of disturbance leading to further disturbance. The observed disturbance is most often the cumulative result of a series of compounding disturbance factors.” “An assessment of disturbance, in relation to the ability of the bushland to self- maintain, has been used as the basis of defining condition ratings for plant communities. …” Department of Environmental Protection (2000). 1.2) ISOLATING THE SIGNS AND SYMPTOMS OF CHANGE This sets the stage for the central conundrum/s in condition analysis - ‘How is condition and especially directional change (or an adverse trend) in condition to be separated from characteristics of a vegetation type that have little to do with condition in other words how are symptoms of adverse change to be separated from characteristics of identity (and the usual processes which maintain identity)?’ There is no easy answer to this. It requires due diligence in terms of assembling sufficient background (including the current & historical context) on the vegetation type in question to be able to make an informed judgement of how it fits into a spectrum of states. Where the vegetation type is very small the next closest equivalent type may have to suffice. Overall this can be approached in a number of ways. They all have to do with building a strong context for the vegetation and a strong sense of its identity. The most objective is to assess full plant diversity from many sites roundabout and then look at the balance of native species and weeds in light of disturbance (ideally this would be assessed numerically). There are other ways of establishing context and achieving reference points. Many national systems use a benchmark system with information on reference states for set vegetation types (however, this has its limitations, especially in light of the high diversity of species and communities in W.A. and the logistics of setting up such a system, but also due to an incomplete state of knowledge, flux in taxonomy, and differences in scale and voracity of information). There is much value in many years experience of vegetation survey and assessment which can clearly help inform an understanding of condition (but this does not mean that this comes without individual bias). An intermediate approach shadows the sort of approach that those with long- standing experience of vegetation assessment would use. It employs a mixture of: i) reference material ii) preliminary reconnaissance and observation and iii) cultivating a sense of the polarities of state and whether these are due to resident processes or imposed disturbance. It takes time to develop a sense of ecological pattern and process. Unfortunately the whole exercise is likely to get progressively more difficult for each generation as the drift in condition continues. 1.3) A PLETHORA OF FACTORS This endeavour is like making a diagnosis.

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