Sammanfattning

The seasonal distribution of fires is one fire regime variable which has received little attention with regard to its effects on plants. For species with a short life-span that recruits after fire, the seasonal timing of a fire can be expected to be important due to effects on potential growth period and reproduction. We observed phenology and reproductive output in two annual and fire-dependent Geranium species in the southern part of the European boreal forest. In a garden experiment with the two species under two levels of nutrition, we established cohorts of seedlings at several dates over three summers. Time from germination to flowering and first mature seed differed little between the two species and levels of nutrition; i.e. plant size or level of nutrition had almost no effect on phenology. However, emergence time controlled the timing of reproduction. Most plants emerging before the second week of July in the garden experiment bolted the same year. Plants emerging later behaved as winter-annuals and started to flower in June the following year. A similar dichotomy was observed for populations of Geranium spp at a number of burnt sites that differed in date of fire. This response is likely controlled by photoperiod. Nevertheless, at sites that burnt early some plants did not bolt in the same season; probably an effect of variable seedling emergence dates in the populations. In both the field and garden experiment, there were plants entering reproduction too late to produce mature seeds. Our results indicate that management fires should be conducted either very early, or during July and August to achieve a high seed production in these rare forest plants.

Publicerad i

Forest Ecology and Management
2009, Volym: 257, nummer: 8, sidor: 1725-1731
Utgivare: Elsevier

SLU författare

• Risberg, Lotta

  • Institutionen för skogens ekologi och skötsel, Sveriges lantbruksuniversitet
    

• Granström, Anders

  • Institutionen för skogens ekologi och skötsel, Sveriges lantbruksuniversitet
    

Globala målen

SDG15 Skydda, återställa och främja ett hållbart nyttjande av landbaserade ekosystem, hållbart bruka skogar, bekämpa ökenspridning, hejda och vrida tillbaka markförstöringen samt hejda förlusten av biologisk mångfald


UKÄ forskningsämne

Ekologi
Botanik


Publikationens identifierare

DOI: https://doi.org/10.1016/j.foreco.2009.01.031

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/40668