Growth and performance of bare and pot rooted seedlings of Loblolly pine (Pinus taeda L.) after plantation

Seedling production of P. taeda in plastic bags is economically more expensive than bare-rooted method due to limited space for root development (root rotation) and its negative effects on subsequent seedlings growth and performance at field. The aim of the study was to estimate the mortality of the bare-rooted seedlings, particularly after planting at field. The hypothesis was that if the seedling production, transportation and plantation perform in adequate method and time, there will not be significant differences between the bare and the pot rooted seedlings survival and growth. The trial consisted of two stands of P. taeda seedlings (each containing 60 seedlings) with 2×2 m Spacing. The bare and pot rooted seedlings were planted at each stand, separately. The growth and survival parameters were measured annually up to three years at end of growth period. The results showed that although height growth of the pot rooted seedlings was significantly more than the bare-rooted seedlings up to two years after plantation, but there was not significant difference at third year. The collar and breast height diameter of the pot-rooted seedlings was significantly more than the bare-rooted seedlings, where as the quality of the bare-rooted seedlings was significantly better than the pot-rooted seedlings. Moreover, survival of the bare-rooted seedlings (75%) was slightly less than the pot-rooted seedlings (88%)

Leaves polymorphism and fruit shapes variation of Sorbus torminalis (L.) Crantz in Hyrcanian forest

Sorbus torminalis (L.) Crantz as a rare native species in Iran which grows between 70 to 2400 meters high sea level in Guilan province. Sorbus torminalis with yellow autumn color and edible fruit make it as a multipurpose tree for future. The objective of this study was to investigate the morphology type of leaves and fruits shape. Four observation sites were selected in different elevation. The leaves samples were collected at 6 meters height of tree in north and south aspect. Leaves width, leaves length and petiole were measured. Due to scarce fruit, nearly 2 Kg fruit were collected from 6 trees in each site. Fruit shape was distinguished through visual examination of 600 fruits. Length and width of fruit was measured. Obtained results were showed that the Sorbus torminalis revealed high polymorphism in leaves shape. Two distinct Sorbus torminalis fruit type were observed spheroid (apple shape) and ellipsoid (pear shape) rounded. The highest mean value of fruit length was 12.47mm from Gardelehposht site was significantly different with the other studies sites. The highest mean value of fruit width was 9.97mm from Janbehsara site which was highly significant difference with other studies site. This study was the first step in fulfilling the criteria enabling characterization and assessment of variability which facilitate Sorbus torminalis germplasm recognition and exchange

Linear programming approach for optimal forest plantation

The aim of this research was to identify species suitable for plantation. We first identified species for potentially suitable for plantation based on ecological capabilities regarding soil properties. We determined the area of plantation for different species based on ecological capabilities. Then, we collected relevant data such as growth patterns of different species, labor requirements for plantation and plantation cost. A linear programming model and two integer linear programming models were used for optimization. The appropriate species based on ecological capabilities were ash, elm, maple, oak and bald cypress. A linear programming model was used based on ecological capabilities classification to determine the land area of different species for plantation. Then, two integer linear programming models were employed to select the species for plantation. We set ecological properties unequal for all of the species in the first run of the integer programming model. Two groups were classified: group one included maple and ash; group two included bald cypress, oak and elm. The second integer programming model assumed equal ecological properties for all the species. Results of linear programming showed that maple and bald cypress were appropriate for plantation at the site and their plantation areas should be 151.3 and 355.3 ha, respectively. Results of the first integer linear programming model showed that maple and bald cypress would be economically profitable for plantation. The results of the second integer linear programming model showed that only bald cypress would be appropriate for plantation

Genetic variability and heritability of some morphological and physiological traits in Fagus orientalis Lipsky along an elevation gradient in Hyrcanian forests

The purpose of the present study was to evaluate the genetic variability and heritability of some morphological and physiological traits in Fagus orientalis Lipsky along an elevation gradient in northern forests of Iran. Beech leaves were sampled from southern and northern crown parts of healthy mature trees along an elevation gradient comprising sites situated at 700 m, 1,200 m and 1,700 m above the sea level. Our statistical analysis showed that the investigated traits differed significantly between the populations. The results indicated the lowest and the highest coefficients of variation for the high (1,700 m) and middle elevation populations (1,200 m) for leaf length, petiole length, leaf area, specific leaf area, dry weight, specific dry weight, leaf index and petiole index traits. With increasing elevation, mean leaf width, distance from leaf base to the leaf maximum width, dry weight and petiole index increased. The plasticity of leaf length, specific leaf area, specific dry weight, petiole index and petiole length peaked at middle elevation, and with increasing elevation, the plasticity of these traits declined. The distance from leaf base to the leaf maximum width had the highest coefficient of genetic (75.5%) and phenotypic (75.5%) variation. The heritability results showed that there were differences in all traits, and that the highest heritability was recorded for the distance from the leaf base to the leaf maximum width (99.95 %). The results suggest that the studied beech populations responded to the environmental changes by changing their leaf traits in different ways at different altitudes