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Volume 10, Issue 2, 2025
Online ISSN: 2466-4367
Volume 10 , Issue 2, (2025)
Published: 30.12.2025.
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Contents
19.12.2022.
Research paper
Comparing 16-year-old shortleaf and loblolly pine growth and yield on a north Mississippi afforested site
This analysis compares the growth and yield of 16-year-old shortleaf pine (Pinus echinata Mill.) and loblolly pine (Pinus taeda L.) planted on retired fields near Holly Springs in north Mississippi. The 1-0 bareroot shortleaf seedlings were planted in early March of 2005, while bareroot 1-0 loblolly pine 2nd-generation seedlings were planted during the third week of March in 2005. For both species, the site was subsoiled. Within the plantations of each species, four plots were established for each species and total height and diameter at breast height (dbh) were measured. Volumes were then estimated using appropriate combined-variable volume equations. Loblolly pine had substantially greater growth rates relative to shortleaf pine, producing on average across the four plots (n = 4) 48.4 m-2 of basal area ha-1. This basal area was 42.6% greater than the 34.0 m-2 of basal area ha-1 observed within the shortleaf pine. For merchantable volume, defined as all trees with a dbh of 10.16 cm and greater up to a diameter-outside bark (dob) of 5.08 cm, the loblolly pine m-3 volume ha-1 of 424 was 2.36 times greater than that of shortleaf pine. Merchantable volumes were converted to tons and a revenue of $3.61 was assumed per ton of pulpwood. A theoretical 3rd row thinning with no logger select of the remaining rows was conducted – hence the thinning was assumed to remove 33% of the standing merchantable yield. Loblolly pine had a stumpage value of $97.39 ha-1 which was 136% greater than the shortleaf pine economic value of $41.23 ha-1.
Curtis VanderSchaaf, John D Kushla
19.12.2022.
Research paper
The bigger the tree the better the seed – effect of Sessile oak tree diameter on acorn size, insect predation, and germination
Sessile oak is one of the ecologically and economically most important tree species in Europe. Recently, the importance of this species has been particularly highlighted in the context of climate change, where it is expected that these species will play a significant role within their natural range and beyond. To regenerate and expand the range of the sessile oak forests, a large amount of healthy acorns is needed. The acorn production and the acorns themselves are endangered by a large number of abiotic and biotic factors. As oak trees of different sizes do not produce the same amount of seed of the same quality, we investigated how the sessile oak tree diameter affects the acorn size, insect infestation, and germination rate. On the other side, as the acorn size influences the attack rates of the most significant acorn pest – Curculio glandium (Marsham, 1802), and the germination rates of both the damaged and healthy acorns we also investigated how the acorn dimensions influence the insect damage and germination rates, and how the insect damage influences the germination rates. We determined that the oak tree size influences some oak seed characteristics that are important for forest regeneration, while it does not affect others. A greater acorn yield was recorded on the bigger oak trees. The tree dimensions also had a significant influence on the acorn size. Greater average length, as well as greater average acorn diameter, were recorded on bigger trees. Although the tree size affects the acorn size, it does not influence the acorn insect predation rates or its germination rates. These parameters are affected by the acorn size itself. Bigger acorns had a greater germination rate. Insects preferred smaller acorns and had a significantly negative influence on the germination rate.
Jovan Dobrosavljevic, Jovana Devetaković, Branko Kanjevac
19.12.2022.
Research paper
Provenances vs. microhabitat influence on field performance of Quercus robur seedlings
Provenance trials, as the subject of continuous analyses, provide empirical information about the plasticity of tree species. Changing climate and environmental conditions likely favor genotypes with high levels of plasticity. Finding the suitable provenance for the reintroduction of pedunculate oak to habitats that are threatened and where this species no longer exists provides important information for the targeted use of the available gene pool. The dominant ecological factors in the development of pedunculate oak forests are groundwater level and changes in the hydrological regime of habitats. In this study, we established nursery and field provenance trials to test two pedunculate oak seed provenances from different hydrological conditions to investigate the influence of seedlings' provenance and field microhabitat on growth parameters and survival. In the nursery trial, the height and ground level diameter were measured. After three years in the pilot object, the height and diameter were analyzed again, as well as the survival. To determine the microhabitat influence planting area was divided in two ways: three repetitions and two planting blocks. In this study, significant differences in analyzed growth parameters between the chosen provenances were obtained at the end of the first vegetation period. In later ontogenetic phases influence of the provenance is missing. As the difference between provenances disappears, the influence of microhabitat occurs (significant differences between repetition or planting blocks). After the second year of development, no significant difference was observed between the two provenances of different hydrological regimes, but there are significant differences between the microhabitats in the afforested area (established pilot object).
Ivona Kerkez Jankovic, Mirjana Šijačić-Nikolić, Marina Nonić
19.12.2022.
Research paper
Net benefits of silky oak (Grevillea robusta) for small farmers in Musanze District, Rwanda
This study was conducted in Musanze district, Rwanda, to evaluate the net benefits of silky oak (Grevillea robusta) production for small farmers. A semi-structured questionnaire was administered to 100 households distributed in four villages. The cost-benefit ratio was used as a decision-making tool. A diameter tape and a Haga altimeter were used to measure the DBH and height of grevillea and other dominant agroforestry tree species. Results indicate that 66 % of laborers were family members, gaining 625 Rwf per person day with grevillea production (US$ 0.61, with 4-8 hours of work per day. Also, results show that farmers earn 57,950 Rwandan Francs (Rwf) per hectare per year (US$ 57.48 from grevillea products (stakes, poles, charcoal, and timber), whereas the mean investment in grevillea production is 54,200 Rwf ha-1 year-1 (US$ 53.76. The net farm income is 3,225 Rwf (US$ 3.2 ha-1 year-1. The net benefit from grevillea product is affected by poor farmer data record as the majority of67% of respondents has not attended any formal education. However, farmers gain additional benefits of US$ 628, US$ 298, and US$ 224ha-1 year-1 from potatoes, maize, and bean, respectively, depending on their crop choice during intercropping with grevillea. The benefit-cost ratio is 1.06, which highlights the modest profitability of growing grevillea on the farm. In addition, soil erosion control, soil fertility increase, landslide prevention, shade provision, microclimate improvement, and biodiversity conservation were reported as ecosystem services of grevillea on the farm. Growth performance of grevillea (diameter at breast height, tree height, and volume) is analyzed in all four villages. The study shows that growing grevillea is profitable for smallholder farmers via tree products and farm benefits, including ecosystem services aspects.
Rene Niyomfura, Gerald Kapp, Canisius Patrick Mugunga, Jean de Dieu Niyomugabo
19.12.2022.
Research paper
Use of calcium in bareroot pine nurseries
Bareroot nursery managers may apply dolomite, gypsum, or Ca-nitrate to increase Ca in nursery soils. Although a few managers follow S.A. Wilde’s recommendations and maintain soil at levels of 500 to 1,000 μg g-1 Ca, there is no need to keep Ca levels this high. In contrast, managers at sandy nurseries apply Ca when soil tests drop below 200 μg g-1 Ca. In fact, acceptable pine seedlings have been produced in irrigated soil with <100 μg g-1 available Ca. In plantations, asymptomatic wildlings grow when topsoil contains 17 μg g-1 Ca. In sandy soils, applying too much gypsum can result in a temporary Mg deficiency and too much lime will result in chlorotic needles. Managers apply Ca when foliar levels fall below a published “critical value.” The belief that the critical value for Ca varies by stock type is not valid. In fact, numerous “critical” values are invalid since they were not determined using growth response curves. Critical values determined for small seedlings using CaCl2 in sand are apparently not valid for use in bareroot nurseries. At bareroot nurseries, the soil extractable Ca level can decline during a year by 30 μg g-1 or more. Harvesting 1.7 million pine seedlings may remove 20 kg ha-1 of Ca but irrigation can replace this amount or more. When water contains 5 mg l-1 Ca, 600 mm of irrigation will add 30 kg ha-1 Ca. In some areas, 1,000 mm of rainfall will supply 7 kg ha-1 Ca. Even when a Mehlich 1 test shows no exchangeable Ca in the topsoil, pine needles on tall trees may exceed 2,000 μg g-1 Ca due to root growth in subsoil. There are few documented cases of deficient pine needles (<300 μg g-1 Ca) in irrigated nurseries in Australia, New Zealand, Scotland and in the Americas. Even when soil fumigation delays the inoculation of ectomycorrhiza, bareroot pines have adequate levels of Ca. Typically, foliage samples from pine nurseries contain at least 1,000 μg g-1 Ca. Samples from 9-month-old seedlings range from 300 to 11,000 μg g-1 Ca. Although the “critical value” for Pinus echinata foliage is not known, 1-0 seedlings with 300 μg g-1 Ca were not stunted and apparently grew well after ouplanting.
David B. South
19.12.2022.
Research paper
Potential of new planting container in Quercus robur seedlings production – first report
Container production of forest seedlings needs constant improvement, so in the aim to test the new container type this research was conducted. Quercus robur seedlings were produced in the container made of natron paper and compared with seedlings produced in commonly used container types in Serbia. Q. robur seeds were sown in the first week of November 2020 in a total of 30 containers (10 of each type). After the first growing season in the nursery, on November 2021, seedlings’ morphological parameters (root collar diameter - RCD, height - H, dry weight of shoot (SDW) and root (RDW), seedling dry weight (SLDW), shoot to root ratio (S:R), sturdiness coefficient (SQ), dry weight of lateral roots (LRDW), percent of lateral roots (%LR), Dickson’s quality index (QI), root-bound index (RBI) as RBI-diameter and RBI-volume, and rooting intensity (ROIN)) were compared using one-way ANOVA. Seedlings produced in the new container showed better morphological parameters such as H, SQ, SDW, RDW, SLDW, LRDW, QI and ROIN. Differences of seedlings from different containers were not detected for H, RCD, SQ, SDW, %LR, RBI-diameter, so we can conclude that seedlings produced in the new container type are similar with other container seedlings. Larger volume of these cells indicate use for Quercus species which have strong roots. Results obtained from the nursery promote use of the new container in forest seedlings production and testing at the field.
Ljubica Mijatovic, Slavko Pavlović, Lidija Jović, Jovana Devetaković, Dragica Vilotić
19.12.2022.
Research paper
Questions about toppling of pine seedlings
When soil is moist and wind is at a gale force, the term used to describe blow down of old trees is windthrow. In contrast, toppling is a term used when planted pines lean more than 15° during the first decade after transplanting. Pines tend to topple more than other conifers and fast-growing species topple more than slow growing genotypes. Large areas of pine plantations have toppled before age 8 years. This paper describes some toppling events that have occurred in 18 countries and includes 16 questions about toppling.
David B. South
30.06.2021.
Research paper
The effect of temperature on the Fusarium sambucinum growth from the one-year-old Fraxinus excelsior seedlings in Montenegro
Species complex Fusarium sambucinum was frequently isolated from ash stands in Montenegro. Previous researches revealed that it is dangerous pathogen for one-year-old seedlings. The aim of this research was to investigate the influence of temeperature on growth and morphological characteristics of morphotype isolated from one-year-old common ash (Fraxinus excelsior L.) seedlings in Montenegro. Growth of Fusarium sambucinum pure cultures on different temperatures was the fastest on 25°C while the absence of growth occurred on 32.5°C. Cultures on optimum temperature were white reddish, aerial and with a lot hyaline, curved multi septate conidia. This research covers basic ecological and morphological characteristics of Fusarium sambucinum strain responsible for high pathogenicity towards one-year-old common ash seedlings in Montenegro.
Aleksandar Vemić, Zlatan Radulović
30.06.2021.
Research paper
Ecological and histological investigation of species complex Diaporthe eres on Fraxinus excelsior seed from Montenegro
Investigation of different seed diseases of common ash has great significance due to occurrence of ash dieback across Europe caused by Hymenoscyphus fraxineus Baral, Queloz and Hosoya (T.Kowalski) and still not completely defined strategies about regeneration of this species. Species complex Diaporthe eres are familiar pathogens of common ash. During the monitoring of health condition of common ash in Montenegro Diaporthe eres was frequently isolated from common ash seeds. The aim of this research was to investigate temperature conditions that contribute to the growth of Diaporthe eres strains from Montenegro in infected seeds and histological characteristics of Diaporthe eres spread in seeds. Growth of Diaporthe eres pure cultures on tested temperatures showed the fastest growth on 25°C and the absence of growth on 35°C. Mechanical damage did not significantly contribute to occurrence of infection. Microscopic examination of heavy infected seeds showed that hyphae of D.eres were visible on outer parts of seed spreading inside the core. In this research we investigated some basic bio ecological characteristics of D. eres associated with decline of F. excelsior seed in Montenegro.
Aleksandar Vemić
30.12.2021.
Research paper
Two studies of the potential of drought preconditioning to enhance deep root production in seedlings of western larch (Larix occidentalis)
Climate change is increasing the frequency and intensity of drought in the western USA. Evidence suggests that drought preconditioning of plants may improve the survival of planted seedlings under dry conditions through enhanced water uptake by roots, but the mechanisms underlying enhanced survival under drought remain unknown. We tested whether the vertical distribution of roots in root plug cross-sections varied with drought preconditioning and seed source. We subjected western larch (Larix occidentalis Nutt.) seedlings from eight different provenances to Low (50-65% gravimetric water content), Moderate (65-75%), and High (≥75%) watering regimes in a nursery. We then investigated dry root mass across four root-plug sections, including the taproot and three lateral root cross-sections (top 1/3rd, middle 1/3rd, and bottom 1/3rd of root plugs). We also tested for carry-over effect of drought preconditioning on the mass of egressed roots observed among cross-sections of potting soil in a 30-day potted study. Root plug mass varied significantly (P< 0.001) with watering regime, root plug cross-section, and an interaction between watering regime and cross-section. Overall, seedlings that received less water produced lateral root plug cross-sections of greater mass, which coincided with taproots of less mass. In contrast to findings from the root plug study, the distribution of egressed root mass among cross-sections of potting soil did not vary with drought preconditioning. This is the first study to assess seedling root growth in response to drought preconditioning in western larch with a focus on the distribution of root mass in root plugs and egressed root mass among soil cross-sections. We expect this work to facilitate future efforts to improve drought hardiness of western larch seedlings. Future improvement of western larch seedlings will require investigation into whether altered root plug mass distribution translates to improved seedling performance in outplanting trials.
Ashleigh Vale, Ehren Moler, Andrew Nelson