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for lessons focussed on
carp, visit FeralFocus
to Unit 3 and follow the link
'The problem with carp'.
forest productivity. Australia spends considerable time and money each year in combating weed problems and protecting ecosystems and primary production on private and public lands.
Along the waterways of the Murray-Darling Basin perhaps the most common weed species are willows and blackberries. There are many different species of willows that have been introduced into Australia, some being more ‘invasive’ and damaging to waterways than others.
Diseases, fungi and parasites
Invasive diseases, fungi and parasites in Australia affect many native plants and animals and agricultural crops. Some diseases have contributed to significant losses of species leading to some becoming threatened or extinct. Among those of concern for aquatic species is the Chytrid amphibian fungus (Chytridiomycosis) (see Module 1.3 in Part 1).
Diseases, fungi and parasites can affect the health of native species, reducing their ability to reproduce or survive. Threatened species with reduced and restricted populations due to other factors are particularly vulnerable to outbreaks caused by these introduced organisms.
Before the activity
1. Visit the portion of the river, stream or wetland you plan to work with and identify the six most common introduced and native species.
2. Explain to students before they go to the site that they will be identifying plants along the river. Demonstrate the use of the field guides, focusing students on leaf shapes, arrangements, buds and seed heads.
3. Describe or show examples of the six local target introduced and native species. (These may be plants or animals).
It will also be helpful
to record any large tree
within the plot, even if it
is not one of the four
dominant species. There might
be less of them but they
are still important!
In the field
1. Divide the class into groups of 3-4 students. Explain that each group will be working in a designated plot. A three by three metre plot is ideal, with one adult assistant per plot for younger students. The plot of each group should border the next so the result is one large, contiguous plot being surveyed.
2. Give each group a copy of the Dominant Species Recording Sheet (see below). Review the categories with the students. Students should describe at least three identifying CHARACTERISTICS of each plant or animal they find. In the REMARKS area, students should note where the organism was found, its health, age or anything unusual about the population.
3. With the aid of field guides, all groups will identify the four dominant species in their plot. In this situation, dominance is based upon which species is the most numerous. Make sure the students also record any of the target introduced species found.
In addition, make sure students do not assume that just because a plant is not one of the target introduced species, that it is native! If students encounter other dominant introduced species in their plot, they should refer to their field guides.
4. If there are too many individuals of one species to count, show the students how to estimate the number by counting the individuals in a one square metre subplot, and then extrapolating for the total area. A section at the bottom of the Dominant Species Chart is provided to compute the percentage of the identified individuals that were native and non-native.
5. While students are identifying the species in their plots, have them draw the major features of their sites and include the locations and names of the plants they found on the back of the sheet. Have them include any feature that could affect the health or make-up of the site.
Analysing the data in the classroom
1. Students may analyse the data from each group or from the class as a whole by developing pie charts and vegetation maps.
Pie Charts: Each group calculates the percentage of the introduced and native species. Combine data from all the groups to develop a classroom pie chart.
Vegetation Maps: The groups combine their plot diagrams showing the locations and identities of plant species. Group members will need to agree on what symbol represents each species.
Carp have invaded most of the rivers, streams and wetlands of the Murray-Darling Basin. They can grow to very large sizes! Photo: copyright The Federal Capital Press Pty Ltd.
2. Have students conduct research on the introduced species found. Ask them to write short reports explaining how the introduced species arrived here, what positive and negative impacts they have had on the environment and wildlife, and what management techniques are, or have been used to control their populations.
3. Ask students to share the findings from their research with the class. Compare the role of wildlife managers and community members. How do community members contribute to the dispersal of introduced species? What can community members do to limit dispersal? Ask the students to reflect on the importance of habitat evaluation in managing introduced species.
Establish with the Catchment Management Authority, natural resource management (or similar body), local council or landholders some long term control plots for the activity.
Establish two plots, three meters square. Leave one plot as the control, and let it develop without disturbances.
For the second plot, try a management technique such as hand removal of all non-native plant species.
This long term project demonstrates how ecosystems change over years. Have classes observe the plots over several years and record, draw or photograph the changes.
With GPS or Google Earth, and GIS mapping programs (if available), have students survey and map native plant communities along their local river reach.
See Invasive or not? worksheet.