Template-Type: ReDIF-Article 1.0 Author-Name: Asadollah Mataji Author-Workplace-Name: Department of Forestry, Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran Author-Name: Ali-Asghar Vahedi Author-Workplace-Name: Research Department of Natural Resources, Mazandaran Agricultural and Natural Resources Research and Education Center, AREEO, Sari, Iran Title: Distribution attributes of natural canopy gaps in the Hyrcanian mixed-oriental beech forests Abstract: 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 (< 200 m2), medium (200‒500 m2) and large gaps (500-1 000 m2) 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 m2 can be introduced for monitoring and specifying the forest stand dynamics. Keywords: clustered pattern, disturbance, Hyrcanian forest, stand mosaic Journal: Journal of Forest Science Pages: 367-375 Volume: 67 Issue: 8 Year: 2021 DOI: 10.17221/150/2020-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/150/2020-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202108-0001.txt Handle: RePEc:caa:jnljfs:v:67:y:2021:i:8:id:150-2020-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Masoomeh Soleimany Author-Workplace-Name: Department of Forestry, Sari Agricultural Sciences and Natural Resources University, Sari, Iran Author-Name: Jamshid Eslamdoust Author-Workplace-Name: Department of Forestry, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Tehran, Iran Author-Name: Moslem Akbarinia Author-Workplace-Name: Department of Forestry, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Tehran, Iran Author-Name: Yahya Kooch Author-Workplace-Name: Department of Forestry, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Tehran, Iran Title: Soil aggregate stability index and particulate organic matter in response to differently afforested lands in the temperate regions of Iran Abstract: Aggregate Stability Index (ASI) and particulate organic matter (POM) are strongly influenced by land use and management. This work illustrates the effects of plantations on ASI and POM-C and POM-N in northern Iran. Three plantations of P. deltoides (PD), T. distichum (TD), A. subcordata (AS), and a fourth site ‒ adjacent abandoned lands (BL, as control) were selected. Soil samples were taken within 16 quadrats of each plantation and BL from the two depths of 0-15 cm and 15-30 cm during the summer. Soil C was significantly higher under TD (2.10%) than under BL (2.02%) > PD (1.61%) > AS (1.30%). Soil N was found in ranked order of AS (8.99%) > TD (7.82%) > PD (5.30%) > BL (3.68%) (P < 0.019). The significantly higher ASI was found under TD (57.49) in comparison with PD (53.10), BL (51.23), and AS (36.57). The POM-C was as follows: TD (0.209%) > PD (0.141%) > AS (0.139%) > BL (0.075%) (P = 0.020). The highest POM-N was found under TD (0.035), followed by AS (0.0284%), PD (0.0288%), and BL (0.007%). The results indicate the positive effect of afforestation on soil ASI and POM-C and POM-N, especially in the surface layers of soil. Keywords: afforestation, organic matter, soil properties, tree species, land use Journal: Journal of Forest Science Pages: 376-384 Volume: 67 Issue: 8 Year: 2021 DOI: 10.17221/20/2021-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/20/2021-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202108-0002.txt Handle: RePEc:caa:jnljfs:v:67:y:2021:i:8:id:20-2021-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Ondřej Špulák Author-Name: Jana Hacurová Author-Workplace-Name: Forestry and Game Management Research Institute, Research Station at Opočno, Opočno Title: The influence of growing medium composition on pine and birch seedling response during the period of simulated spring drought Abstract: Climate change increases the earliness and effect of spring dry spells. The efforts to reduce their negative effects on tree regeneration include improvement in physical properties of soil aimed at an increase in water retention and availability. Clinoptilolite from the group of zeolites belongs among such water-absorbent natural materials. The article aims to assess the effect of clinoptilolite admixture in a growing medium, along with different fertilizer concentration, on the growth of pine and birch seedlings and their development during simulated drought. A common (reference) growing medium was tested along with 4 treatments of the growing medium with clinoptilolite. The birch responded to the fertilizer concentration more intensively than to the clinoptilolite admixture and was more vulnerable to drought damage due to a closer dependence of physiological responses on a decrease in the growing medium moisture. The onset of pine withering was slowest in the reference growing medium. A positive effect of clinoptilolite addition on the growth of pine seedlings was confirmed but its unambiguously positive effect on overcoming of spring dry spells was not demonstrated. Clinoptilolite addition with higher fertilizer rate was found as fully unsuitable. Keywords: volume moisture, growth, flushing, withering, clinoptilolite, zeolite, dry spells Journal: Journal of Forest Science Pages: 385-395 Volume: 67 Issue: 8 Year: 2021 DOI: 10.17221/39/2021-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/39/2021-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202108-0003.txt Handle: RePEc:caa:jnljfs:v:67:y:2021:i:8:id:39-2021-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Seray Özden Keleş Author-Workplace-Name: Department of Forest Engineering, Kastamonu University, Kastamonu, Turkey Title: Variation in morphological and wood cell traits in coppice stems of Populus nigra L. and Salix alba L. Abstract: Coppice management is an ecologically important silvicultural practice to provide the quicker and higher potential of wood biomass production for industrial demands. Understanding morphological and anatomical responses of coppiced trees could help to determine the quantity and quality of wood and thus provide better management of coppiced tree plantations for short-time biomass production. However, there is a little investigation in morphological and anatomical adaptation in different fast-growing tree species. The present study, therefore, studied how morphology and anatomy vary between two fast-growing coppices of Populus nigra L. (black poplar) and Salix alba L. (white willow). Each coppiced tree was grown in a similar habitat and was at a similar age. However, each coppiced tree showed different morphological and anatomical plasticity in their stems in response to environmental factors. Poplar coppices showed better anatomical properties due to greater vessel diameter, fibre length, fibre width, fibre wall thickness, and ray height; however willow coppices had better morphological plasticity which had higher average stem height and ring width. The results suggest that willow coppices had the greater height growth potential even at 2 years of age than poplar coppices. Keywords: coppicing, fast-growing species, wood cell anatomy, plant morphology Journal: Journal of Forest Science Pages: 396-407 Volume: 67 Issue: 8 Year: 2021 DOI: 10.17221/208/2020-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/208/2020-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202108-0004.txt Handle: RePEc:caa:jnljfs:v:67:y:2021:i:8:id:208-2020-JFS