Study

The potential of prescribed burning to perpetuate snow tussock Chionochloa rigida grassland, Flagstaff Scenic Reserve, Otago, New Zealand

  • Published source details Calder J.A., Wilson J.B., Mark A.F. & Ward G. (1992) Fire, succession and reserve management in a New Zealand snow tussock grassland. Biological Conservation, 62, 35-45

Summary

Deliberate (prescribed) fire management had not previously been used in nature reserve management in New Zealand. An accidental fire burned 70 ha of the 100 ha Flagstaff Scenic Reserve on the outskirts of Dunedin City (southeast South Island), in autumn (March) 1976. Subsequently another 20 ha was deliberately burnt in spring (September) 1976 to assess the potential of prescribed burning to perpetuate narrow-leaved snow tussock Chionochloa rigida grassland.

Four areas were sampled: unburnt tussock grassland/scrub (altitude 500-540 m); spring-burnt grassland (510-600 m); lower autumn-burnt grassland (500-590 m); and upper autumn-burnt grassland (580-668 m; reserve summit).
 
In 1978, 1980, 1984 and 1988, within each area 10 (8 m-long) transects were established at random. Four 0.5 × 0.5 m quadrats were placed along each transect, within quadrats species shoot frequency was determined in 25, 10 x 10 cm squares.
 
Average species frequencies were calculated for the four quadrats in each transect. This data was used to develop a computer model to predict vegetation change.

Average maximum leaf lengths of three important perennial, tussock grassland species after 1976 changed as follows:
 
New Zealand flax Phormium spp. - in 1978 leaves were shorter (significantly so) in autumn-burnt (51 cm) than in spring-burnt areas (60 cm). A significant difference remained in 1980 and 1984, but by 1988 they had converged to around 70 cm.
 
Chionochloa rigida- in 1978 leaves in autumn-burnt (around 40 cm) were shorter than in spring-burnt areas (55 cm). By 1988 the two treatments had converged (leaves around 75 cm). Shoot frequency was low after fire, but generally increased.
 
Astelia nervosa - leaves were shorter initially in 1978 in autumn-burnt (around 35 cm) compared to spring-burnt areas (45 cm). By 1988, leaf length had increased, but was still greater in the spring burnt area (60 cm vs. 51cm)
 
Of numerous non-native species, after both fires common bent Agrostis capillaris frequency increased dramatically (>60% shoot frequency) compared to unburnt controls (20%), but declined more quickly in spring-burnt areas. By 1988, in the unburnt area, a native shrub, manuka Leptospermum scoparium, was replacing Chionochloa. The model predicted medium-term replacement of non-native grassland by Chionochloa tussock grassland, with succession towards Leptospermum scrub after several decades.
 
Based on these results, the authors recommended that Chionochloa grassland at this altitude should be burnt every 15-40 years to maintain the tussock grassland community. Such a low frequency burning regime would prevent loss of tussock grassland to any high intensity fires that might otherwise occur (i.e. if a high fuel load was allowed to accumulate as a result of no burning management taking place), and retard scrub invasion.
 
 
Note: If using or referring to this published study, please read and quote the original paper, this can be viewed at: http://www.sciencedirect.com

Output references

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 17

Go to the CE Journal

Subscribe to our newsletter

Please add your details if you are interested in receiving updates from the Conservation Evidence team about new papers, synopses and opportunities.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust