Drought and Heat Triggers Sudden and Severe Dieback in a Dominant Mediterranean-Type Woodland Species


Ecosystems in Mediterranean climate regions are projected to undergo considerable changes as a result of shifting climate, including from extreme drought and heat events. A severe and sudden dieback event, occurring in regionally significant Eucalyptus gomphocephala woodland in Western Australia, coincided with extreme drought and heat conditions in early 2011. Using a combination of remote sensing and field- based approaches, we characterized the extent and severity of canopy dieback following the event, as well as highlighted potential predisposing site factors. An estimated 500 ha of woodland was severely affected between February and March 2011. Tree foliage rapidly discolored and died over this period. In the af-fected portion of the woodland, approximately 90% of trees greater than 20 cm DBH were impacted, while in the adjacent unaffected woodland 6% showed signs of damage. Tree density in the unaffected area had approximately 4.5 times more trees than the affected woodland. Precipitation drainage patterns are thought to explain the difference between affected and unaffected woodland. Dropping groundwater levels, a relatively shallow soil profile, and extreme drought and heat in 2010-2011 are thought to predispose water-shedding sites to drought-triggered canopy dieback during extended periods of dryness. Tracking forest health changes in response to severe disturbance is an important key to deciphering past and future vegetation change.

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Matusick, G. , Ruthrof, K. & Hardy, G. (2012). Drought and Heat Triggers Sudden and Severe Dieback in a Dominant Mediterranean-Type Woodland Species. Open Journal of Forestry, 2, 183-186. doi: 10.4236/ojf.2012.24022.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Bates, B. C., Hope, P., Ryan, B., Smith, I., & Charles, S. (2008). Key findings from the Indian Ocean Climate Initiative and their impact on policy development in Australia. Climate Change, 89, 339-354. doi:10.1007/s10584-007-9390-9
[2] Breshears, D. D., Cobb, N. S., Rich, P. M., Price, K. P., Allen, C. D., Balice, R. G., Romme, W. H., Kastens, J. H., Floyd, M. L., Belnap, J., Anderson, J. J., Myers, O. B., & Meyer, C. W. (2005). Regional vegetation die-off in response to global-change-type drought. Proceedings of the National Academy of Sciences, 102, 15144-15148. doi:10.1073/pnas.0505734102
[3] Cai, Y. F., Barber, P., Dell, B., O’Brien, P., Williams, N., Bowen, B., & Hardy, G. (2010). Soil bacterial functional diversity is associated with the decline of Eucalyptus gomphocephala. Forest Ecology and Management, 260, 1047-1057. doi:10.1016/j.foreco.2010.06.029
[4] Close, D. C., Davidson, N. J., Swanborough, P. W., & Corkrey, R. (2011). Does low-intensity surface fire increase waterand nutrient-availability to overstorey Eucalyptus gomphocephala? Plant Soil, 349, 203-214. doi:10.1007/s11104-011-0862-3
[5] Commonweath of Australia, Bureau of Meteorology (2011). Perth in 2010: One of the hottest and driest years on record. URL (last checked 19 September 2011). http://www.bom.gov.au/climate/current/annual/wa/archive/2010.perth.html.
[6] Costa, A., Madeira, M., & Oliveira, A. C. (2008). The relationship between cork oak growth patterns and soil, slope and drainage in a cork oak woodland in Southern Portugal. Forest Ecology and Management, 255, 1525-1535. doi:10.1016/j.foreco.2007.11.008
[7] Croton, J. T., & Reed, A. J. (2007). Hydrology and bauxite mining on the Darling Plateau. Restoration Ecology, 15, S40-S47. doi:10.1111/j.1526-100X.2007.00291.x
[8] Curry, S. J. (1980). The association of insects with eucalypt dieback in South Australia. In K. M. Old, G. A. Kile, & C. P. Ohmart (Eds.), Proceedings of CSIRO conference on Eucalypt Dieback in Forests and Woodlands, Canberra, 4-6 August 1980.
[9] Damesin, C., Rambal, S., & Joffre, R. (1998). Co-occurrence of trees with different leaf habit: A functional approach on Mediterranean oaks. Acts Oecologia, 19, 195-204. doi:10.1016/S1146-609X(98)80024-6
[10] Department of Environment and Conservation, City of Rockingham (2010). Proposed Final Management Plan, Rockingham Lakes Regional Park. Perth: Conservation Commission of Western Australia.
[11] Department of Water, Government of Western Australia (2008). Rockingham-Stakehill Groundwater Management Plan. Perth: Department of Water, Government of Western Australia.
[12] Edwards (2004). Environmental correlates and associations of tuart (Eucalyptus gomphocephala DC.) decline. Master’s Thesis, Perth: Edith Cowen University.
[13] Ellison, A. M., Bank, M. S., Clinton, B. D., Colburn, E. A., Elliott, K., Ford, C. R., Foster, D. R., Kloeppel, B. D., Knoepp, J. D., Lovett, H. M., Mohan, J., Orig, D. A., Rodenhouse, N. L., Sobczak, W. V., Stinson, K. A., Stone, J. K., Swan, C. M., Thompson, J., Con Holle, B., & Webster, J. R. (2005). Loss of foundation species: Consequences for the structure and dynamics of forested ecosystems. Frontiers in Ecology and the Environment, 3, 479-486. doi:10.1890/1540-9295(2005)003[0479:LOFSCF]2.0.CO;2
[14] Fox, J. E. D., & Curry, S. J. (1980). Notes on the tuart tree (Eucalyptus gomphocephala) in the Perth area. Western Australian Naturalist, 14, 174-186.
[15] Galiano, L., Martínez-Vilalta, J., Sabaté, S., & Lloret, F. (2012). Determinants of drought effects on crown condition and their relationship with depletion of carbon reserves in a Mediterranean holm oak forest. Tree Physiology, 32, 478-489. doi:10.1093/treephys/tps025
[16] Giorgi, F., & Lionello, P. (2008). Climate change projections for the Mediterranean region. Global Planet Change, 63, 90-104. doi:10.1016/j.gloplacha.2007.09.005
[17] Jump, A., Hunt, J. M., & Pe?uelas, J. (2006). Rapid climate changerelated growth decline at the southern edge of Fagus sylvatica. Global Change Biology, 12, 2163-2174. doi:10.1111/j.1365-2486.2006.01250.x
[18] Klausmeyer, K. R., & Shaw, M. R. (2009). Climate change, habitat loss, protected areas and the climate adaptation potential of species in Mediterranean ecosystems worldwide. PLoS ONE, 4, e6392. doi:10.1371/journal.pone.0006392
[19] Lloret, F., Siscart, D., & Dalmases, C. (2004) Canopy recovery after drought dieback in holm-oak Mediterranean forests of Catalonia (NE Spain). Global Change Biology, 1, 2092-2099. doi:10.1111/j.1365-2486.2004.00870.x
[20] Mitchell, K. (2001). Quantitative analysis by the point-centered quarter method. New York: Hobart and William Smith Colleges.
[21] Petrone, K. C., Hughes, J. D., Van Biel, T. G., & Silberstein, R. P. (2010). Streamflow decline in southwestern Australia, 1950-2008. Geophysical Research Letters, 37, L11401. doi:10.1029/2010GL043102
[22] Pook, E. W., Costin, A. B., & Moore, C. W. E. (1966). Water stress in native vegetation during the drought of 1965. Australian Journal of Botany, 14, 257-267. doi:10.1071/BT9660257
[23] Sommer, B., & Froend, R. (2011). Resilience of phreatophytic vegetation to groundwater drawdown: is recovery possible under a drying climate? Ecohydrology, 4, 67-82. doi:10.1002/eco.124

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