Recurrent fires, natural or anthropogenic, occur in a number of ecosystems, particularly in savannas, Mediterranean shrublands, temperate grasslands and boreal forests. In Hungary, fires might have played an important role in maintaining the openness of the forest steppe on the Hungarian Great Plain during the early Holocene. Recently, fires pose a threat to certain habitats, such as Austrian pine plantations and juniper-poplar steppe woodlands. Furthermore, under a warmer, dryer and more variable climate projected for the near future, fire risk in general is expected to increase. During the last two decades, numerous, mostly foreign studies reported that smoke derived from burning vegetation and its aqueous solution (smoke-water) had beneficial effects on the regeneration of a range of species. Here we review the main results of these studies on the prevalence, physiological mechanism, ecological significance and potential for practical use of this phenomenon, and highlight the importance of such investigations in Hungary. To date, smoke or smoke-water has been shown to stimulate seed germination for more than 1200 species from phylogenetically distant plant families and different continents. The phenomenon is particularly frequent in Mediterranean shrublands, for both dicotyledons and monocotyledons, annuals and perennials, but it has also been recorded for species from non-fire prone semi-deserts, numerous arable weeds and cultivated plants. Based on literature data, enhanced germination in response to the active compounds of smoke has been detected for about half (33) of 65 natural species in the Hungarian flora and for 8 cultivated plants, while negative effects were found for 7 species (10%) only. In addition, smoke can improve seedling growth and vigour, and promote flowering and fruiting. The most probable mechanism of smoke action is that it performs similar functions than endogenous plant growth regulators do or interacts with these hormones, and/or induces stress-like responses similar to that of certain environmental stresses (e.g. drought or temperature extremes). The germination stimulating capacity is mainly attributed to karrikinolide (3-methyl-2H-furo[2,3-c]pyran-2-one, KAR1), a butenolide-type compound identified in smoke. The aqueous solution of KAR1 is effective over a wide range of concentrations (from 10-4 to 10-9 M) for many species. Further studies are needed to assess the significance of the promotive effects of smoke in the composition and structure of plant communities (e.g. diversity, invasive species, fungal colonization of roots) during postfire succession. The beneficial effects of smoke and smoke-water enable the application of smoke-technology in conservation (e.g. habitat restoration, ex-situ conservation of threatened species) and cultivation of several crops and vegetables with lower costs and smaller impacts on the environment.
|Translated title of the contribution||The role of smoke derived from burning vegetation in the regeneration of plants|
|Number of pages||24|
|Journal||Journal of Landscape Ecology|
|Publication status||Published - Jan 1 2012|
ASJC Scopus subject areas
- Nature and Landscape Conservation