Climate change, unpredictable cold waves and possible brakes on plant migration
Article first published online: 24 MAY 2010
© 2010 Blackwell Publishing Ltd
Global Ecology and Biogeography
Volume 19, Issue 5, pages 642–648, September 2010
How to Cite
Jalili, A., Jamzad, Z., Thompson, K., Araghi, M. K., Ashrafi, S., Hasaninejad, M., Panahi, P., Hooshang, N., Azadi, R., Tavakol, M. S., Palizdar, M., Rahmanpour, A., Farghadan, F., Mirhossaini, S. G. and Parvaneh, K. (2010), Climate change, unpredictable cold waves and possible brakes on plant migration. Global Ecology and Biogeography, 19: 642–648. doi: 10.1111/j.1466-8238.2010.00553.x
- Issue published online: 4 AUG 2010
- Article first published online: 24 MAY 2010
- Climate change;
- plant diversity;
- unpredictable cold waves
Aim Increases in annual mean temperature in the course of current climate change are expected to facilitate mass species migration towards higher altitudes and latitudes. However, this migration may be slowed, or even temporarily reversed, by infrequent and unpredictable episodes of low winter temperatures. Iran experienced a severe cold wave in January and February 2008, giving an opportunity to observe the effects on a large number of woody plant species, many growing further north than their natural ranges.
Location The study was carried out in the National Botanical Garden of Iran (35°44′20.06″ N; 51°10′25.66″ E).
Method To estimate the damage caused to each individual woody plant in the garden, we adopted the following protocol; at the start of the growing season, at the end of March and beginning of April 2008, all woody species were inspected for damage. In the case of evergreens this took the form of obvious damage to foliage, usually manifested as severe browning. In the case of deciduous species, damage was recognized by the failure of all or part of the plant to produce new leaves; all affected individual plants were labelled. In July all labelled plants were rechecked and, based on whole or partial above-ground die-back, a final list of damaged individuals was produced.
Results As expected, the majority of native and exotic species introduced from cold temperate habitats showed no freezing injuries. Many woody species in the garden were damaged or killed, despite their previous survival and growth, in many cases for up to 40 years. The majority of taxa (101 out of a total of 145) that suffered freezing-induced damage were evergreens.
Main conclusions The results indicate that despite an increase in mean annual temperature, unpredictable lethal cold waves may retard the expansion of plants towards higher altitudes and latitudes. Broadleaved evergreen species from warm climates were particularly badly affected, with many species suffering high rates of mortality.