Comparison of developmental stages in Beech-Hornbeam stands using non-spatial indices of stand structure

Forest stand structural development occurs over time and is commonly studied based on initial, optimal and decay developmental stages. The purpose of this study was to evaluate the capability of non-spatial indices for differentiating among developmental stages of beech-hornbeam stand in Haji-Kola- Tirankoli forest of Sari in Mazandaran province. Three sample plots were selected in each developmental stage (totally 9 sample plots). The characteristics of trees with a diameter > 7.5 cm were measured in each plot, including species, diameter at breast height and total height. The results of analysis of variance revealed significant differences amongst the developmental stages for basal area, volume, density, density of large trees, standard deviation of diameter and height, diameter and height of overstory, leaf area index, relative light intensity, species richness of over story, basal area of large to mature trees, modified Frelich-Lorimer index. Nevertheless, other attributes including DBH, density of trees > 100 cm, deadwood diameter, and number of dead wood, Gini coefficient, Doliucort index, Structural Complexity index, and Cox index did not differentiate among the developmental stages. The structure triangle and the Frelich-Lorimer index were shown to properly determine the stage of stand development

Spatial patterns in untouched beech (Fagus orientalis Lipsky) stands over forest development stages in Kelardasht region of Iran

Determination of trees spatial patterns in each development stage illustrates the dynamic of stands during the time and can provide valuable information on the underlying processes, particularly in case of uneven-aged forests. For this purpose, three one- hectare (100m×100m) plots were closely selected at three development stages of initial, optimal and decay in an untouched, unmanaged and uneven-aged beech (Fagus orientalis Lipsky) dominated forest in the Kelardasht region. Diameter of all trees with dbh greater than 7.5cm together with their coordinates, using azimuth-distance method, were recorded and fully mapped. Spatial point pattern analyses by Ripley's K- function showed that, while the number of stems decreases from initial stage toward decay stage, the spatial pattern of trees in initial, optimal and decay stages are highly aggregated, random and slightly aggregated, respectively. This research emphasizes the application of spatial statistics for investigating tree spatial patterns. It's believed that forest managers for any insight of natural processes, need to such information from untouched stands as a key reference for any close to nature intervention in under managing forests and for sustainable management of forest ecosystems, as well

Effects of position within gap and relative light intensity on quantitative regeneration attributes of six tree species (Case study: Loveh forest- Golestan province)

Identifying regeneration characteristics is a decisive prerequisite in forest stands management. Therefore, the objective of this research was to 1) present the most appropriate tree species for reforestation within stand gaps and 2) study the effect of relative light intensity on regeneration characteristics. Quantitative characteristics were measured in 10 gaps at district one of Loveh forest in Golestan province. Results showed differing frequencies of species depending on gap positions and relative light intensities. Except checker (Sorbus torminalis) regenerations, no significant difference was observed between mean of spring shoot length within gap positions. Annual height growth of checker was maximum for 40% relative light intensity, while the annual diameter growth of hornbeam (Carpinus betulus) and wild cherry (Prunus avium) were maximum for relative light intensity ranging between 30 and 40%, respectively. No significant difference for relative light intensities was observed between other spices characteristics. Therefore, the study concludes that the highest attention should be paid to species mixtures and their ecological requirements for reforestation within the gaps

Effects of various water storage methods on plantation of Greek juniper (Juniperus excelsa M. B.)

This research was carried out in Sirachal Research Station in order to identify the best method for Greek juniper (Juniperus excelsa M. B.) afforestation as one of the most important forest species in Iran. Three year-old juniper saplings were transported to Sirachal and were planted in a Split-Plot Randomized Block Design with water harvesting (in 5 treatments including using organs of native plants and shrubs at the bottom of pits, using 1×1 m plastic film at the surface of pits, using Aquasorb polymers mixed with the pits soil, semi-circular bonds and control) as main factor and shading (in 2 level of using tree sprouts as artificial shading and control) as secondary factor in 3 replication and 16 saplings per replication. Measured variables were survival, collar diameter, height, and crown area and sapling vitality at the end of growing season of 2015 and 2016. Results showed that rainwater harvesting had significant effect on survival juniper saplings for both 2014 and 2015 years and current annual increment of collar diameter. The highest value of these parameters was noticed for plastic film treatment though the highest decrease of survival from 2014 to 2015 was noticed for this treatment too. Both rainwater harvesting and shading had no significant effect on height, crown area, vitality and their changes during the studied years. Overall, results confirmed the possibility of rainfed afforestation of Greek juniper in high altitude of Southern Alborz Mountain. To achieve this goal, usage of nylon at the surface of plantation pits is recommended. There is no need to use artificial shading for planted saplings

Tree and regeneration conditions within development stages in Kelardasht beech forest (Case study: reserve area-Langa)

This study was carried out in the reserve area of district one of Langa region in Kelardasht. Development stages including initial, optimal and decay were identified and one sample plot with one hectare area  (100 m×100 m) was selected in each development stage. Quantitative characteristics of saplings with diameter at breast height less than 7.5cm were determined in the micro plots. One hemispherical photograph was taken by Fish-eye camera lens in order to study the status of light in development stages as well as the relationship between quantitative and qualitative characteristics of saplings and relative light intensity. Light intensity parameters were processed by Gap Light Analyzer (GLA) V.2 software. Results showed that mean frequency of seedlings and saplings and mean annual height growth increased by increasing of relative light intensity in the decay stage. Frequency of trees decreased from initial to optimal stage and then towards decay stages. Maximum and minimum of stocked volume was measured at initial and decay stages, respectively. Stocked volume of larger timber classes in development stages was higher than small timber classes. Considering the obtained results, we can recommend to establish the regeneration in the optimal stage by creating gap and can improve the quality of the regeneration in the initial and decay stages by silvicultural interventions

Effect of gap size and position within gaps on growth characters and survival of chestnut-leaved oak (Quercus castaneifolia C. A. Mey.), Cappadocian maple (Acer cappadocicum Gled.) and Caucasian alder (Alnus subcordata C. A. Mey.)

In this study,six canopy gaps with medium (200-500 m2) and large (> 500m2) sizes were selected in Shastkolate forest. In each gap, micro sample plots (6×6 m) were established at the center and north, east, south and west directions of each gap. Within each micro plot, 12 seedlings of chestnut-leaved oak (Quercus castaneifolia C. A. Mey.), Cappadocian maple (Acer cappadocicum Gled.) and Caucasian alder (Alnus subcordata C. A. Mey.) were planted in spacing of 1×1 m. Height growth and photosynthetic rate of seedlings were studied during the growth season, while the survival rate was calculated in the end of season. Data were analyzed using spilt split plot plan and SNK test. Results showed that survival rate of seedlings of all three species decreased with increasing gap size. Oak seedlings showed the highest survival rate in both large and medium sized gaps. The maple seedlings showed the lowest survival rate in the large gaps. The maximum height growth of seedlings was measured in the center of gaps; this was decreased in north, west, south and east edges of the gaps, respectively. The larger the gap size the higher was the height growth of alder and oak and seedlings, while that of maple was higher in the medium gaps. Therefore one can conclude that planting of oak and alder seedlings in the center of large gaps could bring more promising results, while planting of maple in the center of medium and edges of large gaps would be more effective

Seasonal alteration of peroxidase in branch and leaves of Eucalyptus viminalis Labill.

The morphology of deciduous plants changes seasonally. In addition, deciduous and ever-green plants encounter with internal changes as a consequence of seasons. Enzymes activities alter with changes of temperature, drought and salinity. Plants adapt to environmental changes with alteration of enzymes activities. In this study, the peroxidase activity was measured in leaves and shoots of Eucalyptus viminalis during a year. Peroxidase activity was measured by spectrophotometer (530 nm) by use of Worthington method. Data were analyzed to determine statistical relationship in peroxidase activity of individual trees and seasonal changes of enzyme activity by SPSS software. Results showed that peroxidase activity was different in individual trees. The difference of peroxidase activity in different individual trees was little in April, July and January but differences were higher in September and November. The peroxidase activity decreased in all individual trees from April to July. Peroxidase activity of leaves was higher than those of branches in all of studied months. There was negative correlation between some month of peroxidase activity (