Sausas mezotrofas priedes mežaudzes izmaiņas skrejuguns ietekmē: otrais gads pēc meždegas

Inglés. The paper presents results of the post-fire succession in a dry mesotrophic pine (Pinus sylvestris) forest in Rucava, Latvia. The results after the first year were summarized in an article published in the previous volume of this journal. Analysis of the succession in a forest stand affected by surface fire in 2014 shows several tendencies. The two years observations suggest that the fire has caused significant impact on the pine stand. In comparison to the undisturbed forest stand, there is an increasing spatial and temporal heterogeneity. It is indicated by the dynamics of the number of species, the vitality of forest stand, recovery processes, and other parameters. Before the fire, the visually estimated cover of the plants in the fire-disturbed and undisturbed forest stands were different for four vascular plant and four moss species (in total, eight species), in 2015 (first year after fire) – for 11 vascular plant and three moss species (in total, 14 species), and in 2016 (two years after fire) – for ten vascular plant and five moss species (in total, 15 species). In the fire-disturbed forest stand, already in the first year after fire significant differences in cover were found for 11 species, in the second year – for 12 plant species. In the first two years after fire, dying of pines and intensive establishment of pioneer species, especially Betula pendula, was observed. The post-fire succession includes several processes that are indicated by changes in the species composition (establishment or expansion of certain species) and are typical for hemiboreal pine forests: expansion of nitrophilous and annual species (Chamaenerion angustifolium, Senecio sylvestris, Taraxacum officinale, Rubus idaeus), expansion of grasses (Deschampsia flexuosa), and increase in substrate wetness (Calamagrostis canescens, Polytrichum commune).

Letón. Rakstā aplūkota vidēja vecuma (63 gadi) normāla mitruma mezotrofas priežu audzes stāvoklis divus gadus pēc meždegām. Analizēti šādi audzes parametri: vaskulāro augu un virsaugsnes sūnu sugu sastopamība, zemsedzes kopējais un sugu acumēra un stratificētais segums, priedes atmirums un vainagu stāvoklis, kā arī dabiskās atjaunošanās procesi. Meždegu skartajā audzes daļā, salīdzinot ar uguns netraucēto audzes daļu, pirmajos divos gados pieaugusi audzes telpiskā un temporālā heterogenitāte: notiek meža pioniersugu – bērza un apses – sējeņu ieviešanās. Sugu sastāva un atsevišķu sugu daudzuma izmaiņas pēc meždegām atspoguļo hemiboreālajos priežu mežos pēc traucējumiem notiekošos procesus – ruderalizāciju, graminifikāciju un higrofitizāciju.