Spremembe pritalne vegetacije pragozdnih rezervatov Pečka in Strmec v obdobju 1983-2015 : magistrsko delo - 2. stopnja

Javornik, Jernej (author), Nagel, Thomas Andrew (mentor), Rozman, Andrej (co-mentor)

Analizirali smo spremembe pritalne vegetacije (zelišč in grmovnic) v pragozdnih rezervatih Pečka in Strmec na podlagi ponovnega popisa 85 vegetacijskih ploskev iz leta 1983. Ploskve smo ponovno popisali leta 2015 po prvotni, Piskernikovi fitocenološki metodi. Na osnovi primerjave treh kazalcev diverzitete (vrstna pestrost, Shannonov indeks in indeks vrstne poravnanosti) smo ugotovili znatno zmanjšanje vrstne pestrosti pritalne vegetacije v obeh rezervatih. Analiza sprememb številčnosti na podlagi ekofizioloških in funkcionalnih lastnosti rastlin je pokazala, da se je najbolj znižala diverziteta fanerofitov in vrst z večjo potrebo po svetlobi, medtem ko je ostala pestrost večine sencovzdržnih rastlin in geofitov nespremenjena. Prav tako se je znižalo povprečno zastiranje nekaterih vrst z visokimi vrednostmi specifične listne površine (SLA). Sklepamo, da je omenjeno posledica vzajemnih učinkov sestojne dinamike (poslabšanja svetlobnih razmer zaradi povečanega zastiranja podstojnih sestojnih plasti) ter objedanja s strani velikih rastlinojedov. Čeprav v nobenem izmed rezervatov nismo ugotovili termofilizacije (premik k bolj toploljubni vrstni sestavi) združb pa zmanjšanje številčnosti zmerno vlagoljubnih vrst ter zmanjšanje SLA-jev združb (tehtana aritmetična sredina SLA-jev vseh vrst na ploskvi) v Pečki vseeno nakazujejo na vpliv klimatskih sprememb na pritalno vegetacijo v raziskovalnem obdobju, kar pa z zasnovo naše raziskave ne moremo nedvoumno potrditi. Zato bi bile na to temo dobrodošle dodatne raziskave.

• Language: Slovenian
• Keywords: pritalna vegetacija, vegetacijska dinamika, pragozdovi, Pečka, Strmec
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [J. Javornik]
• Year: 2016
• Number of pages: X, 92 f., [43] f. pril.
• PID: 20.500.12556/RUL-115255
• UDC: 630*2(043.2)=163.6
• COBISS.SI-ID: 4367526
• Publication date in RUL: 21.04.2020

Secondary language

• Language: English
• Title: Long-term changes of understory vegetation in old-growth forests reserves Pečka and Strmec between years 1983 and 2015

Abstract

We investigated changes in understory vegetation biodiversity in two old-growth Abies- Fagus forest reserves (Pečka and Strmec) in SE Slovenia between 1983 and 2015. Resurveys of 85 historical semipermanent vegetation plots were done using the same method (Piskernik phytosociological method) as was used in the original surveys. According to changes in diversity measures (species richness, Shannon diversity index and species evenness index) significant diversity losses during the study period were found in both reserves. The largest declines were observed for light-demanding species and phanerophytes highly susceptible to browsing, while diversity of shade-tolerant species, especially geophytes, showed little change. These changes were consistent with the canopy closure and increase in red deer densities in both reserves during the study period. In Pečka we also documented a decline of some shade-tolerant, moisturedemanding species and an overall decrease of community mean specific leaf area (SLA) values. We argue that this could be an influence of climate change (increase in mean annual temperatures and decrease in annual precipitation during study period), but this assumption clearly needs further investigation.