DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu
ŠUMARSKI LIST 9-10/1967 str. 27 <-- 27 --> PDF |
sem u slučajevima kada je na oštećenom mestu došlo do ulančavanja sekundarnih negativnih uticaja abiotičke i biotičke prirode. f) Brzina zatvaranja pukotina, bez obzira na njenu veličinu, u mnogome zavisi od kvaliteta, odnosno ukupne fiziološke snage i aktivnosti ozleđene biljke. Kod jačih sadnica ovaj proces teče znatno brže, jer su zarasle pukotine dužine 117 i 134 cm nađene već polovinom juna. Kao interesantno ostaje i dalje da se vrše osmatranja o ponašanju sadnica oštećenih od mrazopucina. Naročito je važno utvrditi brzinu zarašćivanja ncsraslih mrazopucina, kvalitet drveta na oštećenom mestu, otpornost na vetrolome i snegolome, otpornost na uticaj parazita. Od posebnog je interesa pratiti ponašanje oštećenih sadnica i oštećenih mesta na uticaj niskih temperatura u budućnosti. Navedeni podaci o pojavi pucanja stabala topole ovde su dati samo u onom obimu koji se tiče odnosa sa ekstremnim niskim temperaturama. Međutim, koliko je ova pojava u vezi i sa nekim drugim činiocima a koji se verovatno nalaze u tehnologiji gajenja i fiziološko-anatomskim odlikama na ovaj način uzgajanih biljaka, ostaje da se utvrdi na osnovu izučavanja oštećenih topolika, kao i putem eksperimentalnih ogleda koji su u toku. INJURIES FROM LOW TEMPERATURES TO PLANTS OF EURAMERICAN POPLARS CULTIVATED» IN PLANTATIONS Summary During ihe winter of 1963´64 there occurred a fissuring of stems in a great number of plants in 2-year-old Poplar plantations over larger areas of Eastern Slavonia, Baranja and Bačka. This phenomenon was recorded in all localities where in 1962 new Poplar stands were established irrespective of the various different conditions of the soil, the regime of underground and flood waters, and the degree of applied agrotechnical and silvicultural measures. The numb:r of fissured stems on 1200 ha of these plan´ations in individual localities amounted to 13.0—28.4% in the clone 1-214, and 11.2—12Va in the clone »robusta«. The number of splits occurring most frequently on the southern and southwestern sides is varying in individual plants. It ranges from 1 to 8, averaging 1.96, while the length of the split is from 2 to 178 cm., averaging 32.46 cm. As the mentioned phenomenon was not recorded earlier — although Poplar stands in Baranja have been established since 1956 after similar or identical silvicultural techniques — the splitting of stems is correlated to the detrimental influence of the extreme high and low daily air temperatures characteristic of the late November and December of 1963. Because this phenomenon represents a serious problem in intensively managed plantations for Pcplarwood production, complex investigations were aiming at determining the true causative agent of this phenomenon. |