Faculty of SITE Northern Territory University Flora & Fauna Survey Techniques
what is flora and fauna survey?
why survey?
factors to consider
preparing to sample
flora survey techniques
vegetation descriptions
sampling concepts
fauna survey techniques
analysing data
presenting data

Vegetation descriptions

Floristic surveys are concerned with an assessment of species composition of vegetation, rather than the structure. These are favoured for large-scale (small area) studies of a detailed botanical nature. The information can be integrated for larger area studies, e.g. vegetation classification and mapping. The identification of species is essential for floristic mapping.

  1. Qualitative Floristic Description - presence/absence
    Qualitative floristic measures document the actual species comprising a community, rather than its physical structure. The simplest floristic description of a vegetation type is simply a list of the species present.

  2. Semi-quantitative and Quantitative Description - measures of abundance
    Often the species list is accompanied by a measure of abundance of each species.
    Measures of abundance include

These areas are detailed below.

Please Read

Please read

Your textbook
pages 111-138

Identificationtop of page
The importance of accurately identifying species is paramount in surveys, as this is the primary unit of measurement.

The use of field guides and taxonomic keys are important components of surveying flora. Many local field guides and keys are available. The identification of specimens should be checked at your state or territory herbarium, where voucher specimens should also be lodged.

Listed below are the some references and local field guides.

Brock J. (1988). Top End Native Plants. Reed, Chatswood NSW.

Cowie I., Short P.S. & Ostercamp Madsen M. (2000). Floodplain flora: a flora of the coastal floodplains of the Northern Territory, Australia. Australian Biological Resources Study, Canberra.

Dunlop C., Leach G. & Cowie I (1995). Flora of the Darwin region. Conservation Commission of the Northern Territory, Palmerston.

Kenneally K.F., Edinger D.C. & Willing T. (1996). Broome and beyond: plants and people of the Dampier Peninsula, Kimberley Western Australia. Western Australian Department of Conservation & Land Management, Perth.

Simon B.K. & Latz P. (1994). A key to the grasses of the Northern Territory. Northern Territory Botanical Bulletin No.17. Conservation Commission of the NT, Palmerston

Smith N.M. (1995). Weeds of natural ecosystems: a field guide to the weeds of the Northern Territory. Environment Centre of the NT, Darwin.

Wheaton T. (1994). (editor). Plants of the Northern Rangelands. NT Department of Lands, Housing and Local Government, Darwin.

Whightman G. (1989). Mangroves of the Northern Territory. Conservation Commission of the Northern Territory, Palmerston.

Covertop of page

Cover is the percentage area of the ground occupied by aerial parts of a species when viewed from above. It includes basal area, canopy cover, ground cover, and leaf area cover. Total cover of an area may exceed 100% because of overlayering of species (stratification).

Various ways of measuring cover include

  • visual estimates within quadrats - can be used to rank the species in order of abundance (i.e. list the most abundant species first, then the second most abundant species and so on)
  • single cover pins (point quadrats)
  • frames of pins or cross-wires.

Adds information about relative abundance. Visual estimates are fast compared to quantitative descriptions. Can be applied to vegetation units of any extent. Good method to use where it is difficult to know where one individual starts and another ends, e.g. grasslands.

Visual estimates become more difficult as the size of the plant increases. The precision of visual estimates varies widely from person to person. Precision of estimates is not linear with cover. Use of pins and frames is tedious and time-consuming.

Densitytop of page

Density is the number of individuals of a species per unit area.

It is accurate, allows direct comparison between different areas and species, and is an absolute measure. For long lived perennial species, measures remain relatively stable from year to year, such that the method may be useful for baseline inventory.

Less suitable for the herbaceous layer, especially when there are numerous plants to count or identification of individuals is difficult (e.g. many grasses and mosses). It is most often applied to larger plants such as trees, shrubs and more prominent perennial forbs. Can be tedious counting small or very dense individuals.

Frequencytop of page

Frequency is the probability of finding a species in a particular area. It can be measured by taking a number of quadrats and recording presence/absence in each, or in each of the sub-divisions of the quadrat.

Simple to measure as it only requires identification of the species in each quadrat, not the number of each species. Useful when individuals cannot be distinguished.

Frequency is dependent on quadrat size, and the frequency obtained reflects the pattern of distributions of the individuals as well as their density. For example, if frequency declines over time, it may be because individual plants are more sparsely scattered over the entire area, or because the range of the species distribution has constricted.

Biomass yieldtop of page

Biomass yield is the fresh or dry weight of vegetation per unit area (for all species or individuasl).

This is an accurate and repeatable method.

This is a destructive method. It is also labour intensive which tends to result in a reduction of samples collected, and therefore the representativeness of overall sampling strategy.

Basal Areatop of page

Basal area is the diameter of an individual plant at breast height (dbh).

This is an accurate and repeatable method which can give a measure of potential forestry yield. Used for trees.

For more information
Please view


1. http://www.rfa.gov.au/rfa/
Appendices 1 and 2 of the Regional Forests Agreement provide details of two plot based floristic surveys.
"Compilation and Validation of State Forests Flora Data - Eden CRA region" - a report undertaken for the NSW CRA/RFA Steering Committee, 24 Nov 1997. Prepared by the State Forests of NSW.

  1. The Eden Burning Study Area Vegetation data
    The objective was to examine the effects of integrated harvesting and fuel reduction burning regimes on dry sclerophyll forests.
    The objectives are
    • to describe pretreatment patterns of floristic variation in relation to broad habitat parameters
    • to investigate impact of treatments on understorey floristic patterns
    • to investigate response of individual species to treatments e.g. changes in abundance, response mechanisms, patterns of recovery and reproduction.

    Details are provided of data collection for understorey species.

  2. Yallumba Catchments Vegetation Project
    The objective was to examine the effects of integrated harvesting and unplanned fire on floristic composition.

2. http://www.affa.gov.au/content/

'Vegetation classification and mapping systems for Australian Forest Management' in National Forest Inventory Australia (copy of publication is in the main collection of theCharles Darwin University library).



Refer to Case Study 2 (see 'assignments' section) and your previous ejournal entries of vegetation/flora measurement. Is there anything you want to add to these notes in this topic?
Do you have any preliminary thoughts on methodologies you might use in Case Study 2?
This will form the basis of your next online tutorial.

back to vegetation descriptions

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last updated by lrp@cdu.edu.au 6 August, 2004
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