%0 Research article
%T Stand structure and spatial pattern of regeneration of Pinus sylvestris in a natural treed mire in Latvia
%A Brumelis, Guntis
%A Strazds, Maris
%A Eglava, Zanna
%D 2009
%J Silva Fennica
%V 43
%N 5
%R doi:10.14214/sf.172
%U https://silvafennica.fi/article/172
%X We examined the regeneration patterns of Pinus sylvestris L. in a  natural treed mire in the hemiboreal zone in Latvia. Data on tree stem  age and size was collected in 207 fine-scale plots (10 m<sup>2</sup>) and 4 medium-scale plots (400 m<sup>2</sup>).  Size structure of living and dead trees was also estimated on transects  180-m and 250-m length and 10-m width. In addition, the vegetation was  described in 1-m<sup>2</sup> plots to determine preferred microsites for  P. sylvestris establishment. Pinus sylvestris showed continuous  regeneration by an inverse J-shaped age and size structure. Pulses of  mortality induced by fire were also evident. Regeneration of P.  sylvestris was mostly on Sphagnum magellanicam Brid. hummocks free of  competition from Ledum palustre L. and graminoids, which were found in  small interspersed patches throughout the mire. The spatial pattern of  tree cohorts differed, probably due to changing moisture conditions  altering seedbed conditions and by fire-induced mortality in specific  areas. Recent rapid invasion by Betula pubescens Ehrh. and Picea abies  (L.) Karst. in a post-fire period since 1971 is probably associated with  drier conditions.