Razmatranje pitanja izmene vrsta u monodominantnoj šumi kitnjaka (Quercetum petraeae Čer. et Jov. 1953., subass. tilietosum) – studija slučaja u NP „Đerdap”

Abstract

Na istoj površini na staništu monodominantne šume kitnjaka (Quercetum petraeae Čer. et Jov. 1953., subass. tilietosum) analizirana je struktura sastojina pre i posle prirodne obnove, u fazi kada su u sastojini još zaostala pojedinačna stara stabla kitnjaka. Pre obnove, u sastojini staroj oko 150 godina u 1992. godini, u spratu drveća bio je zastupljen samo kitnjak, stabla su imala pretežno nepravilno izgrađene krošnje i umanjen prirasni potencijal, što su bili elementi na osnovu kojih se planirala obnova u osnovi za gazdovanje šumama. U mladoj sastojini u 2017. godini, pored pojedinačnih, zaostalih, starih stabala kitnjaka, dominira srebrnasta lipa, a u strukturi se ne nalazi biološki potencijal mladih kitnjakovih stabala koji bi predstavljao osnovu za dalji razvoj u sastojini, jer su stabla kitnjaka potisnuta od strane srebrnaste lipe u podstojni i prizemni sprat. Zbog nedefinisanog značaja lipe u sastojini, u osnovi za gazdovanje šumama propisano je prelazno gazdovanje, kojim se predviđa rekonstrukcija sastojine u nekom sledećem uređajnom razdoblju, u cilju vraćanja kitnjaka na stanište s koga je neadekvatnim postupkom obnove istisnut od strane srebrnaste lipe. Na osnovu proučene strukture mlade sastojine predlaže se napuštanje koncepta prelaznog gazdovanja u korist intenzivnog gazdovanja s lipom u aktuelnoj ophodnji. Osnovu za takav pristup dao je dovoljan broj kvalitetnih stabala lipe, odnosno aspiranata za negu i primenu selektivne prorede, kao i njihova dobra prirasna reakcija posle četiri godine od prve prorede. Stara stabla kitnjaka, koja su još uvek prisutna u sastojini, predstavljaju samo prividnu osnovu kontinuiteta s nekadašnjom sastojinom kitnjaka i potrebno ih je ukloniti u sklopu intenzivne i racionanlizovane nege srebrnaste lipe, a delom i integrisati u sastojinu lipe.

Stand structure analysis was conducted before and after natural regeneration (on the same plot) on a site of monodominant sessile oak forest (Quercetum petraeae Čer. et Jov. 1953., subass. tilietosum). In this stage individual old sessile oak trees were still remaining in the stand. Before the regeneration in the 150-yr-old stand in 1992 only sessile oak was rep­resented in the upperstorey. The trees mostly had irregularly developed crowns and reduced growth potential. These were the elements used in planning the regeneration in management plans. Besides the remaining individual old sessile oak trees, silver lime dominates in the young stand in 2017. In the stand structure there is no biological potential of sessile oak trees that could represent the basis for further development because the sessile oak trees are suppressed by silver lime towards the understorey and even the herb layer. Because of the undefined significance of the silver lime in the stand, transient management was prescribed in the man­agement plan so a reconstrucion of the stand should follow in one of the next management periods in order to restore sessile oak on the site as it was suppressed due to an inedequate regeneration procedure. On the basis of the studied stand structure of the young stand, the abandonment of the transient management concept is recommended and introduction of the intensive management approach of slver lime in the current rotation. This was based on the available number of silver lime trees of good quality in the stand, i.e. the aspirants for tending by means of selective thinning and their strong growth response four years after selective thinning. Old sessile oak trees that are still present in the stand are only a simulacrum of the continuity of the current stand with the previous one and they should be removed by means of intensive and rationalized tending of silver lime, and partly integrated in the silver lime stand.