Issue image

Online ISSN:
2466-4367

Volume 8 , Issue 1, (2023)

Published:
04.07.2023.

Open Access

Powered by

Opus logo

Vol 8, No 1 (2023)

Published: 04.07.2023.

Authors in this issue:

David B. South, Dušan Jokanović, Ilan Stavi, Kristina Živanović, Vladan Ivetić,

04.07.2023.

Research paper

Thematic Workshop: Challenges, opportunities, and adaptation strategies to climatic changes in dryland forestry systems

As a part of networking activities of PEN-CAFoRR COST Action (CA19128), the combined meeting took place in Mitzpe Ramon, Israel from 15 to 16 March 2023. In addition to the Core Group and Working Groups Meeting, a Thematic Workshop was organized by the local organizer Dr Ilan Stavi.

Ilan Stavi, Vladan Ivetić

04.07.2023.

Research paper

Variability of morpho-anatomical features of black pine needles at the area of Jastrebac and Goč

In this paper the variability of morphological (needle length and needle width) and anatomical (needle thickness, resin ducts width, epidermis thickness, hypodermis height and number of the hypodermis layers) properties of black pine (Pinus nigra J.F. Arnold) needles were studied at the intra- and inter-population levels. Two mountains in Serbia, Jastrebac and Goč, were selected as experimental plots. Three black pine trees were selected from both localities (6 in total). Obtained results showed that trees on Goč had bigger dimensions of the following elements: needle length, needle width, hypodermis height, number of hypodermis layers, needle thickness and epidermis thickness. On the other hand, only resin ducts width was greater by the trees from Jastrebac. The results of the analysis of variance showed that variation between studied populations, as well as variation between trees within populations was statistically significant for all needle traits except resin ducts width and hypodermis height.

Kristina Živanović, Dušan Jokanović

04.07.2023.

Research paper

Use of sulphur in bareroot pine and hardwood nurseries

During the 20th century, managers at sandy nurseries utilized sulphur (S) to lower soil pH and mitigate the risk of iron deficiency. During that time, however, applying S as a fertilizer was a rare event. At many nurseries, S in rain and irrigation water was sufficient to avoid visual deficiency symptoms. The S status of soil and foliage was typically unknown, and many researchers did not test for S due to the additional cost. Consequently, S became the most neglected macronutrient. While a few nursery trials demonstrated that elemental S reduced damping-off and increased height growth, a majority showed no benefit after applying S at rates lower than 100 kg ha-1.  Even so, by 1980, S-deficiencies occurred at bareroot nurseries in Alabama, Oklahoma, Virginia, Wisconsin, the United Kingdom, and likely in North Dakota and New York. The risk of a deficiency increases when N-only fertilizers are applied to seedbeds. Due to research, experience and the precautionary principle, several managers transitioned to using ammonium sulfate instead of, less expensive, N-only nitrogen fertilizers. After soil tests became affordable, managers began to ask questions about the need to apply S to seedbeds. Only a few hydroponic trials with small pine seedlings have been used to estimate “threshold” or “critical values” for foliar S.  Since an initial 1,500 μg g-1 S value is “unreliable” for pine seedlings, some authors lowered the value to 1,100 μg g-1 and even as low as 500 μg g-1 S. Others ignore all estimates based on total S concentrations and, instead, monitor only foliar SO4 levels.

David B. South