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Dominant C 3 tussock grasses are resilient to the re‐introduction of fire in long‐unburned temperate grasslands
Author(s) -
Morgan John W.,
Salmon Karina L.
Publication year - 2020
Publication title -
applied vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.096
H-Index - 64
eISSN - 1654-109X
pISSN - 1402-2001
DOI - 10.1111/avsc.12476
Subject(s) - tussock , grassland , temperate climate , forb , fire regime , basal area , agronomy , ecology , biology , environmental science , ecosystem
Questions The recovery of dominant tussock grasses following fire is crucial as they contribute disproportionately to the structure and function of grasslands. To determine how resilient native grasslands are to the re‐introduction of fire, we quantify how fire affects the resprouting of the dominant C 3 tussock grasses in long‐unburned grasslands ( Austrostipa spp.) and compare this to the recovery of C 4 tussock grasses ( Themeda triandra ) in grasslands that have had regular exposure to fire. We also quantify if these two grassland types burn in different ways as a result of their different dominant grass compositions. Location Temperate native tussock grasslands on the Victorian volcanic plain, Australia. Methods To determine how fire affects tussock mortality, and whether this differs between C 4 (regularly ) and C 3 (long‐unburned) grasslands, tussocks were permanently marked pre‐fire and re‐censused for survival and growth at seven weeks after fire. To assess whether C 3 grasslands burn in a different way to C 4 grasslands, fire behaviour was quantified at 11 sites. Results Fire behaviour was similar in both grassland types. Both C 3 and C 4 grass tussocks were resilient to fire, despite decades of fire suppression in C 3 grasslands. Tussock mortality was low (<5%) in both C 3 and C 4 grasses. Survival was independent of basal circumference in C 4 Themeda tussocks, but smaller‐sized tussocks (<10 cm circumference) were less likely to survive fire in C 3 Austrostipa grasslands. Basal area declined in both grasses after fire but rate of tiller regrowth after fire was similar for both grass types. Conclusion Long‐unburned C 3 grass tussocks were resilient to a single fire. Future studies should examine the response of C 3 grasses to a fire regime that comprises frequent return intervals to which C 4 grasses are resilient; this may indicate whether C 3 grasses are sensitive to short fire‐return intervals despite resilience to an individual fire event.