male and female leaves and fruits of eleven different taxons of iranian conifers (cupressus sempervirens var. horizontalis, c. sempervirens var. sempervirens, c. sempervirens cv. cereifeormis, juniperus communis subsp. hemisphaerica, j. excelsa subsp. excelsa, j. excelsa subsp. polycarpos, j. foetidissima, j. oblonga, j. sabina, platycladus orientalis and taxus baccata) were collected from diff...

A single 1.41-m-long trunk of Cycas micronesica K.D. Hill was found growing horizontally in natural habitat on the island of Guam. Transverse sections of the trunk showed enhancement of secondary vascular tissues on the lower side by the production of more arcs of accessory vascular cambia and more parenchyma as compared to the upper side. Xylem tracheids were similar in upper and lower sides. ...

Author’s Note: When an Arnold Arboretum volunteer develops an interest in conifers, he inevitably comes under the stimulating influence of Alfred Fordham. So it happened with me. One day Al remarked on a photograph he had taken of Pinus attenuata. The branches were covered with closed cones all the way back to the tree trunk. The conversation then led to the question of how long seeds can remai...

Radiation effects in pine forest Influence of IR on forest ecosystems most clearly revealed itself near the Chernobyl NPP (ChNPP), where magnitudes of absorbed doses reached 'lethal' values, as applied to conifers. Main contribution to absorbed dose was due to beta-radiation of short-living radionuclides. To largest extent the radiobiological effects appeared at injured plantations of pines and...

Long-term investigations revealing the effects of a decay fungus, Chondrostereum purpureum (Pers. Ex Fr.) Pouzar on competition between deciduous and conifer tree species in young forests are missing. Therefore, three different sprout control treatments were tested Norway spruce (Picea abies (L.) H. Karst.) Scots pine (Pinus sylvestris L.) stands by evaluating sprouting ability stumps, level ar...