scholarly journals Distribution attributes of natural canopy gaps in the Hyrcanian mixed-oriental beech forests

2021 ◽  
Vol 67 (No. 8) ◽  
pp. 367-375
Author(s):  
Asadollah Mataji ◽  
Ali Asghar Vahedi
Keyword(s):  
Forest Ecosystems ◽  
Canopy Gaps ◽  
Size Class ◽  
Stand Dynamics ◽  
Natural Disturbances ◽  
Gap Size ◽  
Beech Forests ◽  
Northern Iran ◽  
Size Classes ◽  
Oriental Beech

One of the most important issues indicating the quality and quantity of forest ecosystems is the distribution of natural disturbances resulting in canopy gaps (CGs). The present study was conducted in one of the Hyrcanian beech forests in northern Iran in summer 2018. The gap areas were classified into small (&lt; 200 m<sup>2</sup>), medium (200‒500 m<sup>2</sup>) and large gaps (500–1 000 m<sup>2</sup>) on the basis of full inventory. The univariate Ripley’s L-function was used for introducing the CG spatial pattern. Furthermore, mark correlation function (MCF) and density function (DC) in turns were used for verifying the correlation and frequency of CG size classes in each pattern. The results showed patterns of the gaps in each size class and integrated by the three size classes, they were random and cluster, respectively. Furthermore, the MCF revealed that the gap size classes were independently located in the clusters. The total frequency of the small, medium and large gaps in turns was 32, 49 and 19%, respectively. Although the density share of medium and small gaps in turns was more frequent than the large gap density in the study forest, the results of DC indicated that the frequency of each gap size class was random within each cluster, regardless of their density share. Based on the natural gap aggregations, the base circular mosaic with an area of 5 000 m<sup>2</sup> can be introduced for monitoring and specifying the forest stand dynamics.

scholarly journals Gap characteristics under oriental beech forest development stages in Kelardasht forests, northern Iran

2018 ◽  
Vol 64 (No. 2) ◽  
pp. 59-65 ◽  
Author(s):  
Parhizkar Pejman ◽  
Hassani Majid ◽  
Hallaj Mohammad Hossein Sadeghzadeh
Keyword(s):  
Beech Forest ◽  
Gap Size ◽  
Beech Forests ◽  
Northern Iran ◽  
Development Stages ◽  
Oriental Beech ◽  
Significant Difference ◽  
Gap Characteristics ◽  
Three Stages ◽  
Diameter Classes

This study was carried out to evaluate gap characteristics and gapmakers for different development stages of an oriental beech forest in northern Iran. Development stages of 1 ha square-shaped mosaic patches were identified using 100 × 100 m sampling grid and all gaps within these mosaics were recorded. Gap areas were calculated and classified into four classes and gapmakers were counted and classified into 4 decay and 4 diameter classes as well. Results showed that gaps comprised 13.7, 9.1 and 17.6% of the study area in initial, optimal and decay stages, respectively. There was a significant difference between development stages with respect to gap size and the highest amount was observed in decay stage. Medium-sized gaps were the most frequent in all three stages. Frequency distribution of gapmakers varied among development stages. Our findings revealed that 200–500 m<sup>2</sup> is the most preferable gap size for close-to-nature silvicultural approaches in Hyrcanian beech forests. To achieve this gap size 1–2 trees should be marked for harvesting operations.

Natural regeneration of oriental beech (Fagus orientalis Lipsky) trees in canopy gaps and under closed canopy in a forest in northern Iran

2017 ◽  
Vol 29 (4) ◽  
pp. 1075-1081 ◽  
Author(s):  
Nasrin Nasiri ◽  
Mohammad R. Marvie Mohadjer ◽  
Vahid Etemad ◽  
Kiomars Sefidi ◽  
Leila Mohammadi ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Canopy Gaps ◽  
Northern Iran ◽  
Fagus Orientalis ◽  
Oriental Beech ◽  
Fagus Orientalis Lipsky ◽  
Closed Canopy

Regeneration process in natural uneven-aged Caspian beech forests of Iran (reviewed paper)

2005 ◽  
Vol 156 (12) ◽  
pp. 477-480 ◽  
Author(s):  
Khosro Sagheb-Talebi ◽  
Bahram Delfan Abazari ◽  
Manuchehr Namiranian
Keyword(s):  
Natural Regeneration ◽  
Mixed Forest ◽  
Regeneration Process ◽  
Gap Size ◽  
Beech Forests ◽  
Oriental Beech

Regeneration process was studied within twentytwo gaps produced from natural falling of trees in a semivirgin mixed forest of oriental beech in Iran. The area of the openings varied between 163 m2 and 1683 m2, caused by falling of 1 to 6 trees. Natural regeneration depended on the gap size, and was established within the openings with different compositions.

Canopy gaps and regeneration in old-growth Oriental beech (Fagus orientalis Lipsky) stands, northern Iran

2011 ◽  
Vol 262 (6) ◽  
pp. 1094-1099 ◽  
Author(s):  
Kiomars Sefidi ◽  
Mohammad R. Marvie Mohadjer ◽  
Reinhard Mosandl ◽  
Carolyn A. Copenheaver
Keyword(s):  
Canopy Gaps ◽  
Old Growth ◽  
Northern Iran ◽  
Fagus Orientalis ◽  
Oriental Beech ◽  
Fagus Orientalis Lipsky

Screening of F1 progeny for selection of superior hybrids in mulberry (Morus spp.) - A simple approach PART I: Screening of seedlings in relation to seed size

2017 ◽  
Vol 6 (2) ◽  
pp. 5256
Author(s):  
Daryoush Shafiei ◽  
Prof. Basavaiah*
Keyword(s):  
Seed Size ◽  
Seedling Survival ◽  
Size Class ◽  
Medium Size ◽  
Screening Process ◽  
Size Classes ◽  
Morus Spp ◽  
In The Beginning ◽  
Selection Of ◽  
Size Grading

In mulberry (Morus spp.), the process of selection of promising hybrids from F1 population requires the screening of a large number of progenies and a long period. To develop a simple and faster approach for screening, studies were conducted using F1 seeds of two crosses. The details of screening studies conducted in relation to seed-size and seedling-size are reported separately in two parts. In this part, the F1 seeds were size-graded as small, medium and large seeds; their progenies were raised separately and screened in nursery. There was a considerable degree of variation in size of seeds and medium-size class seeds were in high percentage in both the crosses. The length, width and weight of seeds were also varied between the seed size classes significantly in both the crosses. The seed size classes differ with high significance in shoot length and Root collar diameter and also differ significantly in root length and weight of seedlings. The positive correlation between the seed size and growth of seedlings, seed size and germination, seed size and seedling survival in nursery indicated that size-grading of seeds and rejection of small seeds in the beginning of screening process may help to increase the efficiency of screening by increasing the chances of getting superior hybrids from limited progenies. However, confirmation on the performance of large seedlings from small seed size class may help to draw conclusion. Hence, the studies are continued with size- grading of seedlings in the next part of screening study.

scholarly journals The Abundance of Microcystin-Producing Genotypes Correlates Positively with Colony Size in Microcystis sp. and Determines Its Microcystin Net Production in Lake Wannsee

2003 ◽  
Vol 69 (2) ◽  
pp. 787-795 ◽  
Author(s):  
Rainer Kurmayer ◽  
Guntram Christiansen ◽  
Ingrid Chorus
Keyword(s):  
Growth Rate ◽  
Colony Size ◽  
Population Growth Rate ◽  
Size Class ◽  
Net Production ◽  
Cell Numbers ◽  
Size Classes ◽  
Key Factor ◽  
Genotype Composition ◽  
Working Hypotheses

ABSTRACT The working hypotheses tested on a natural population of Microcystis sp. in Lake Wannsee (Berlin, Germany) were that (i) the varying abundance of microcystin-producing genotypes versus non-microcystin-producing genotypes is a key factor for microcystin net production and (ii) the occurrence of a gene for microcystin net production is related to colony morphology, particularly colony size. To test these hypotheses, samples were fractionated by colony size with a sieving procedure during the summer of 2000. Each colony size class was analyzed for cell numbers, the proportion of microcystin-producing genotypes, and microcystin concentrations. The smallest size class of Microcystis colonies (<50 μm) showed the lowest proportion of microcystin-producing genotypes, the highest proportion of non-microcystin-producing cells, and the lowest microcystin cell quotas (sum of microcystins RR, YR, LR, and WR). In contrast, the larger size classes of Microcystis colonies (>100 μm) showed the highest proportion of microcystin-producing genotypes, the lowest proportion of non-microcystin-producing cells, and the highest microcystin cell quotas. The microcystin net production rate was nearly one to one positively related to the population growth rate for the larger colony size classes (>100 μm); however, no relationship could be found for the smaller size classes. It was concluded that the variations found in microcystin net production between colony size classes are chiefly due to differences in genotype composition and that the microcystin net production in the lake is mainly influenced by the abundance of the larger (>100-μm) microcystin-producing colonies.

The impact of forest roads on understory plant diversity in temperate hornbeam-beech forests of Northern Iran

2017 ◽  
Vol 189 (8) ◽  
Author(s):  
Azade Deljouei ◽  
Ehsan Abdi ◽  
Matteo Marcantonio ◽  
Baris Majnounian ◽  
Valerio Amici ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Beech Forests ◽  
Northern Iran ◽  
Forest Roads ◽  
Understory Plant ◽  
The Impact

Quality of soil from the nickel mining area of Southeast Sulawesi, Indonesia, engineered using earthworms (Pheretima sp.)

2021 ◽  
Vol 8 (4) ◽  
pp. 2995-3005
Author(s):  
Hasbullah Syaf ◽  
Muhammad Albar Pattah ◽  
Laode Muhammad Harjoni Kilowasid
Keyword(s):  
Tap Water ◽  
Soil Aggregates ◽  
Aggregate Size ◽  
Mining Area ◽  
Size Class ◽  
Soil Conditions ◽  
Total N ◽  
Organic C ◽  
Size Classes ◽  
Nickel Mining

Earthworms (Pheretima sp.) could survive under abiotic stress soil conditions. Furthermore, their activities as ecosystem engineers allow for the creation of soil biostructures with new characteristics. Therefore, this study aimed to investigate the effect of the abundance of Pheretima sp. on the aggregate size, physicochemistry, and biology of the topsoil from the nickel mining area of Southeast Sulawesi, Indonesia. It was carried out by first grouping their abundance into zero, two, four, six, and eight individuals per pot and then carrying out tests. The Pheretima sp. were then released onto the surface of the topsoil and mixed with biochar that was saturated with tap water in the pot overnight. The results showed that the abundance of the species had a significant effect on the size class distribution, and aggregate stability of the soil. Furthermore, the size of the soil aggregates formed was dominated by the size class 2.83 - 4.75 mm under both dry and wet conditions. Under dry conditions, three size classes were found, while under wet conditions, there were five size classes. The results also showed that the highest and lowest stability indexes occurred with zero and eight Pheretima sp., respectively. Furthermore, the abundance had a significant effect on pH, organic C, total N, CEC, and total nematodes. However, it had no significant effect on the total P, C/N ratio, total AMF spores, and flagellate. The highest soil pH occurred with zero Pheretima sp., while with six and two members of the species, the total nematode was at its highest and lowest populations, respectively. Therefore, it could be concluded that the species was able to create novel conditions in the topsoils at the nickel mining area that were suitable for various soil biota.

Diet of the endangered spirlin (Alburnoides bipunctatus) at the centre of its distribution in Europe

2018 ◽  
Vol 69 (11) ◽  
pp. 1712
Author(s):  
L. Marszał ◽  
M. Grzybkowska ◽  
D. Błońska ◽  
J. Leszczyńska ◽  
M. Przybylski
Keyword(s):  
Resource Use ◽  
Diet Composition ◽  
Feeding Habits ◽  
Open Water ◽  
Size Class ◽  
Habitat Segregation ◽  
Chironomid Larvae ◽  
Size Classes ◽  
Taxonomic Groups ◽  
Distribution In Europe

The feeding habits of spirlin Alburnoides bipunctatus were investigated in a tributary of the River Vistula (Poland). To evaluate size-related patterns of resource use, fish were assigned to three size classes, defined according to size at first maturation: small (29–70-mm total length, TL), medium (71–90mm TL) and large (91–104mm TL). There was a significant ontogenetic shift in the feeding pattern among size classes, marked by differences in the proportion of the main taxonomic groups of prey consumed: small spirlin primarily consumed chironomid larvae, whereas medium and large spirlin showed a preference for Coleoptera, Ephemeroptera and imagines of unidentified insects. The proportion of prey taken from the water column was significantly lower for small- than medium- and large-sized spirlin. This difference was attributed to the benthic habits of small spirlin compared with medium and large spirlin. The shift to open water feeding in spirlin corresponded with sexual maturation, with habitat segregation between the smallest size class (comprising juveniles) and larger size classes (mature individuals). Size-specific changes in the diet composition of this species have not previously been documented.

Distribution of epicormic branches and foliage on Douglas-fir as influenced by adjacent canopy gaps

2018 ◽  
Vol 48 (11) ◽  
pp. 1320-1330
Author(s):  
John W. Punches ◽  
Klaus J. Puettmann
Keyword(s):  
Branch Length ◽  
Canopy Gaps ◽  
Douglas Fir ◽  
Canopy Gap ◽  
Tree Age ◽  
Gap Size ◽  
Terminal Bud ◽  
Total Branch Length ◽  
A Minor ◽  
Epicormic Branches

The influence of adjacent canopy gaps on spatial distribution of epicormic branches and delayed foliage (originating from dormant buds) was investigated in 65-year-old coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco). Sample trees were selected across a broad range of local densities (adjacent canopy gap sizes) from a repeatedly thinned stand in which gaps had been created 12 years prior to our study. Lengths and stem locations of original and epicormic branches were measured within the south-facing crown quadrant, along with extents to which branches were occupied by sequential (produced in association with terminal bud elongation) and (or) delayed foliage. Epicormic branches, while prevalent throughout crowns, contributed only 10% of total branch length and 2% of total foliage mass. In contrast, delayed foliage occupied over 75% of total branch length, accounted for nearly 39% of total foliage mass, and often overlapped with sequential foliage. Canopy gap size did not influence original or epicormic branch length or location. On original branches, larger gaps may have modestly negatively influenced the relative extent of sequential foliage on branches and (or) slightly positively influenced delayed foliage mass. Delayed foliage appears to contribute substantially to Douglas-fir crown maintenance at this tree age, but canopy gap size had a minor influence, at least in the short term.

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