Veģetācijas sastāva raksturojums Saklaura purva degumos

Abstract

Saklaura purvā 2001. gada vasaras beigās/rudenī cilvēku neuzmanīgas rīcības dēļ izdega nosusināta augstā purva teritorija, bet 2018. gadā izdega daļa aktīva augstā purva. Šī darba mērķis bija izpētīt veģetācijas sastāva atšķirības Saklaura purva teritorijā dažādās pēcugunsgrēka sukcesijas stadijās, salīdzinot ar vietu, kur degums un nosusināšanas ietekme nav bijusi. Katrā deguma vietā un kontrolē ierīkotas divas transektes. Katrā transektē ik pa 10 metriem izvietoti trīs parauglaukumi (10 x 10 m), kuros katrā pieci mazi parauglaukumi (1 x 1 m). Mazajos parauglaukumos novērtēta sugu sastopamība un projektīvais segums (%). Kopumā Saklaura purvā reģistrēta 31 suga, no kurām 14 vaskulāro augu, 14 sūnu un trīs ķērpju sugas. Visās pētītajās vietās sugu sastāvs bija līdzīgs, izņemot dažas indikatorsugas. Atšķīrās sugu segumi veģetācijas stāvos (senajā degumā dominēja sīkkrūmi un ķērpji, nesenajā degumā izteikts sfagnu segums, kontrolē – lakstaugu un sūnu stāvs).

Saklaura Mire has burned twice. Human-caused ignition was fixed in late summer/autumn in 2001 in degraded and drained area near Lake Ramatas Lielezers in northern part of the mire. Another fire was caused by lightning in summer 2018 in active raised bog in south part of the mire. Aim of this study was to compare vegetation composition in Saklaura Mire between both burned sites to analyse different after-burn successions, using natural undamaged area as control. Two transects were established in all three sites. In each transect, three sample plots (size 10 x 10 m) were located with 10 m distance from each other. Five smaller sample plots (1 x 1 m) were established in each large plot to observe species occurrence and percentage cover. In total, 31 species including 14 vascular plant, 14 bryophyte and three lichen species were recorded in all sample plots in Saklaura Mire. Vegetation composition was similar between studied transects, still minor differences were observed in species cover between vegetation layers. In the old burning dominated dwarf shrubs and lichens, while in the recently burned site cover of Sphagnum spp. was much larger. Herbs and bryophytes dominated in the control site.