DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 7-10/1975 str. 49     <-- 49 -->        PDF

bala lužnjaka, odnosno 12,2 m3/ha, ali i 56 stabala crne johe sa 50 m3/ha. I
ovaj podatak ukazuje na poremećaj — pored ostalog — u zoni rizosfere (zamočvarenje
uslijed nemogućnosti otjecanja vode jer je cijeli odjel kao kaseta
čije nasipe čini cesta), drvna masa iznosi 308 m3/ha u dobi od 88 godina. Struktura
sastojine je narušena i može se reći da je tu antropogeni faktor odigrao
vidnu ulogu u stvaranju uvjeta koji su doveli do sušenja lužnjaka.


U zajednici hrasta lužnjaka s velikom žutilovkom i drhtavim šašem {Graf.
6 i Tab. 6) — inicijalna — vodni režim s periodičnim poplavama (uglavnom
za vrijeme mirovanja vegetacije) je vrlo povoljan i sušenja hrasta lužnjaka u
proizvodnom dijelu sastojine nije bilo. Drvna masa iznosi 392,2 ms/ha u starosti
od 88 godina. Sastojina je normalnog obrasta.


U zajednici hrasta lužnja i običnog graba — terminalna — (Graf. 4 i Tab.
4) osušilo se 4 stabla lužnjaka s drvnom masom od 7,2 m3/ha. Drvna masa iznosi
423,8 m3/ha u dobi 77 godina. Obrast je normalan, a struktura nije narušena.


Iz prikazanih rezultata — iako su na malom broju pokusnih ploha i relativno
kratkom vremenu istraživanja — vidljivo je da narušavanjem samo
jednog od edafskih činilaca dolazi do poremećaja, a uz djelovanje i nekih
bioloških stvaraju se preduvjeti za propadanje jedne od naših najvrijednijih
vrsta nizinskog područja hrasta lužnjaka.


Summary


INFLUENCE OF THE HEIGHT AND FLUCTUATION OF THE GROUNDWATER
TABLE ON THE DYING OF PEDUNCULATE OAK (Quercus robur L.)


These investigations on experimental plots were carried out by means of probes
down to depth of ca. 7 m. Along with the usual stand description the duration of
floods (number of flooding days), the number of standing trees died back and
their volume were recorded.


From detailed results of investigations (groundwater level in probes and structure
of stands) it is visible that during the investigations there died back on the
experimental plot — in the initial coenosis of the Slavonian forest (Pedunculate
Oak forest with Genista elata and Carex brizoides) — 14%» of the growing stock
of Peduculate Oak in the management unit »Josip Kozarac«, and 1°/» in the management
unit »Žutica«.


In the optimal community of the Slavonian forest during the investigations
there died back on the experimental plot 4 °/o of the growing stock in the management
unit »Josip Kozarac«, and 7%> in the management unit »Žutica«. The plant-
sociological optimum is represented by the community of Pedunculate Oak with
Genista elata and Carex remota (Genista elatae — Quercetum roboris caricetosum
remotae Horv.).


In the terminal coenosis, i. e. in the forest of Pedunculate Oak and Hornbeam
(Carpino betuli-Quercetum roboris typicum Rauš) there died back during the investigations
on the experimental plot 15 /« of the growing stock of Pedunculate Oak
in the management unit »Žutica«.


These result suggest — although obtained in a relatively short interval of investigations
— that the most suitable water regime was in the management unit
»Josip Kozarac« in the forest of Pedunculate Oak with Genista elata and Carex
remota. This forest is exposed to typical periodic floods. There dried up 12 standing
trees of Pedunculate Oak in the productive part (layer) of the stand with a volume
of 13.8 m3/ha out of a total growing stock of 416.0 m3/ha. Neglected were trees from
the understorey. The dried-up trees were of d = 32.2 cm and h = 26.6 m, while the