o. esmailzadeh

In this research, the capability of indicator species analysis with the emphasis of the group combination concept for determining the pre-classified plant communities was investigated.

For this purpose, the yew ecological groups of sites in the Jahan Nama Protected Area (JNPA) yew forests were firstly classified by TWINSPAN method based of vegetation abundance data and then the indicator species of each ecological groups were derived by using group-equalized indicator value analysis as well as the groups combination concept. The indicator value of the species-group was analyzed by ‘multipatt’ function and its statistical significance was evaluated using the permutation test in the ‘indicspecies’ package. Finally, the importance of indicator species analysis results by considering all possible combinations of JNPA yew groups of sites in order to assigning each ecological groups to pre- classified yew communities in the Braun-Blanquet hierarchical synoptic table were illustrated.

Combining groups of sites in the indicator species analysis not only provide indicator species in target combined groups but also presenting the zero fidelity of those species to non-target groups of sites and allows the differentiation and distinction of plant communities/groups of sites based on both features of prescence and absent of indicator species. While, in the typical indicator special analysis only species-target groups of sites association is taken into account. Results also showed that indicator species analysis by combining groups of sites not only provided the pre- classified JNPA yew communities which were determined by Braun-Blanquet synoptic table but also provides their hierarchical order and also higher syntaxa at the next hierarchical rank in Braun-Blanquet synoptic tables as well as dendrogram.

Consequently, the results of this research reiterate that indicator species analysis by combining groups of sites compared with individual ones provides the more reliable indicator species lists for characterizing plant communities in phytosociological studies. So, we believe that applying indicator species analysis by combining groups of sites approach could be useful in the automatic (expert system) classification of plant communities which is inevitable while an extensive database of vegetation composition is available. Consideration of combining groups of sites in indicator species analysis due to providing common occurrence of indicator species at different hierarchical plant community classification, will improve the capability of expert system method in characterizing of the next higher syntaxa than association as the basic unit in the braun-blanquet synoptic table method.

The aim of this study was to evaluate the efficiency of two expert systems in automatic classification of pre-defined yew (Taxus baccata L.) communities in the central and eastern of the Hyrcanian forests. Therefore, initial plant communities were recognized using Two-Way Indicator Species Analysis (TWINSPAN) based on floristic data of 408 relevés with 400 m2 areas each. To determine representative species, the integrative results of Phi-coefficient index, constancy ratio, and the ratio of average cover were used. Five plant communities were introduced after transferring the initial communities to the Braun-Blanquet synthesis table. The assignment of relevés into the fifth yew associations were done by functional and sociological species groups as two different automatic algorithms of expert system for vegetation classification. The results showed that all relevés in the expert system based on functional species groups were correctly assigned to the target groups. This method was in 100% agreement with the existing yew syntaxa. However, 87 relevés were not assigned to any of the five pre-defined yew associations, or they were assigned to more than one unit in the Cocktail method, which showed 78.7% agreement with the previously yew syntaxa. Finally, our results illustrate that application of expert system based on functional species groups is preferred to sociological species groups in automatically plant community classification due to the importance of consistency and flexibility of vegetation classifications and the correct assignment of relevés to the target units.

In a study of growth and morphological differences among Populus caspica Bornm., trees within Hyrcanian biogeographical region, 15 stands were selected from which one-year cuttings were cut from three plus-trees in each stand. The cuttings were planted in March 2017 at Chamestan Research Station, and the rooted cuttings were cut from the collar base after one year. Cuttings were separated from the one-year sprouts in the next winter and planted based on Randomized Complete Block Design with three replications. We sampled five leaves of each stand-tree seedling on late June and 17 leaf morphological and growth traits as well as collar diameter and height of the rooted cuttings. Data were analysed by hierarchical cluster analysis, two-way ANOVA and Duncan comparison of means test. Four groups were separated according to cluster analysis, among which rooted cuttings from Golestan province showed the highest morphological diversity. The maximum and minimum collar diameters and height growth were observed in seedlings originated from Rostam-Abad (Guilan province) and Golestan National Park (Golestan province) respectively, yet they were similar in some of their morphological traits like their minimum leaf width at 10% of the total length, maximum leaf width, lobe depth and number of veins, which id presumably due to the location of their mother stands at the border of Hyrcanian and Irano-Turanian regions. Thus, they can be considered as morphological traits of P. caspica in the ecotone regions. However, the two regions had a high value for conservation, especially in Rostam-Abad due to high growth rate as well as prominent morphological differences in comparison with the other genotypes. Therefore, they are suggested for being integrated in tree improvement programs in the future.

Rowan is a tree with a very limited distribution in the upper treeline in the Hyrcanian forest. In this study, seven habitats of this tree from east to west of the Hyrcanian forest were identified and seed germination behaviors and diversity in leaf morphological traits were evaluated. Multivariate analysis showed that the studied populations were not differentiated from each other in terms of morphological traits. The results of germination percentage showed that in cold treatment and hot and cold treatment, germination reached about 100% after about 70 weeks. The germination rate in the cold treatment reaches its peak at week 55 and about 90% of the seeds germinate at week 55. In the hot and cold combination treatment, although before week 50 the germination rate reaches its maximum with a cumulative germination percentage of about 40%, but from this week to week 55 the germination rate again slows down and from week 55 to week 60 second drops. It experiences its peak with about 80% germination. The results of the present study showed that the Rowan tree species does not have a high morphological diversity in its habitats in the northern Iran. Due to lack of knowledge on the long-term seed germination of this tree, mountain nurseries have been unsuccessful in producing seedling.

In this study, the diversity of morphological traits of needle in male and female yew (Taxus baccata L.) along the topographic and longitude gradients in the Hyrcanian forests was studied. To this aim, a total of 580 needles from 58 trees were measured in three sites (Amlash, Gazu and Afratakhteh) along the longitudinal gradient of the Hyrcanian forests. A hierarchical or nested analysis of variance was used to assess influencing sex and site on the 6 measured morphological traits of needles. In addition, Duncan's test was used for multiple comparisons of means. Furthermore, principal component analysis (PCA) was used to determine the most important traits and environmental factors in differing sites. Results showed that variation of morphological traits of yew needles is only affected by site factor. However, the influence of sex was not significantly assessed. Results also showed that most morphological traits of yew needles except the form factor were highest in Gazu site that comprised moderate slopes, northern aspects, faced northern humid air and experienced higher growing season due to lower elevation. Generally, morphological traits of yew needles were lowest in Amlash site, which included steep slopes (loss of soil depth) and western aspects (decrease in relative humidity). Yew trees in Afratakhteh site showed intermediate values. Our results imply that sites with cool summers and higher relative air humidity (settling in the humid northern valleys) provide more favorable growth conditions to morphological traits of yew needles compared with sites with higher average annual rainfall across the Hyrcanian forests.

The goal of this study is to evaluate the quality of numerical methods (Phi fidelity and indicator value indices) and non-statistical (constancy ratio and total cover ratio indices) in determining the indicator species of Beech plant communities in the eastern Hyrcanian forests. For this purpose, six ecological groups were first classified using two-way indicator analysis or TWINSPAN. Then, by using sum of the indicator value/association indices or TFVI, as a similarity index for assignment of the plot to the plant communities, with emphasizing the result of species and plant communities association (based on 10 algorithms), the groups were reclassified. Evaluating the compatibility of the results of each classification algorithms with the initial plant communities which have been classified by Braun-Blanquet synoptic table showed that reclassification of sample sites by using TFVI when is derived by group-equalized and incidence-based phi index (84%) and constancy ratio method (82%) showed the highest adaptability with the initial plant communities respectively. Totally, the results of this research revealed that group-equalized and incidence-based phi fidelity and constancy ratio indices have the most priority in assessing the association between species and groups of sites or in determining the diagnostic species of plant communities than the other association indices.

The objective of this study was to determine the floristic composition of the persistent soil seed bank and comparison of its seed bank composition with its above- ground vegetations in Khybus protected forest that is one of the best and most virgin Habitats of Box trees in Hyrcanian forest. The study of ground vegetation was carried out with releve method and the soil seed bank was estimated using the seedling emergence method. For this purpose 64 releves with 400 m2 area were made by systematic- selective method and considering indicator stand concept. For sampling of soil seed bank within each releve, two soil samples were randomly collected by hammering a 20 cm × 20 cm square (400 cm2) hollow metal frame into the soil to a depth of 10 cm. 52 species with mean of 3880 seeds per m-2 emerged from soil seed banks. Pteris cretica L., Hypericum androsaemum, Rubus hyrcanus Woron., Carex sylvatica L., Rubus hyrcanus Woron, Athyrium flix- femina (L.) Roth, Atropa belladonna L. and Diospyrus lotus L. with the mean density of 3132, 213, 154, 125.4, 98.5, 34.4 and 17 seeds per m-2 were exhibited as the most abundant taxa respectively. Forbs, with the possession of the 64 percent seed bank flora, were the most numerous growth forms in soil seed bank. The comparison of seed bank and above vegetation revealed that the similarity between soil seed bank and vegetation is low. Finally, we are concluded that persistence soil seed bank of the study area like other areas, is not capable of restoring the ground vegetation of plant communities.