Jonathan M. Kormann (1), Ernst van der Maaten (2), and Mirko Liesebach (1)*

1. Thuenen Institute of Forest Genetics, 22926 Großhansdorf, Germany.
*E-mail: m.liesebach@t-online.de
2. Chair of Forest Growth and Woody Biomass Production, TU Dresden, 01737 Tharandt,
Germany.

Cryptomeria japonica (Thunb. ex L.f.) D.Don is a conifer species native to Japan that has been tested in several European trials, including in Germany, due to its high growth potential. However, its adaptability to emerging climatic conditions and its response to extreme events such as drought and late frost remain poorly understood. Therefore, we studied trees of C. japonica originating from the northern part of the natural distribution in Japan and planted at a trial site in northern Germany. Using dendroecological methods, we analysed growth responses to extreme drought and late frost events, assessed variation among trees, and examined growth patterns in response to short- and long-term climate variability. Tree growth was primarily limited by moisture availability in February rather than summer drought, yet individuals showed strong sensitivity to extreme years. Within the analysis period, we identified three extreme drought years and one late frost year. Resistance to late frost was lower than to drought, and relative resilience components differed between spring and summer drought events. Although C. japonica achieved high growth rates with diameters up to 58 cm at age 54, its growth in northern Germany was clearly constrained by climatic conditions. Given projected increases in drought and frost extremes, this species may face increased vulnerability under future climate change.

Received: 06 August 2025 / Accepted: 06 March 2026 / Available online: 12 March 2026

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.

Dewi Kresnasari (1,5)*, Muhammad Zainuri (2), Max Rudolf Muskananfola (3),
and Rudhi Pribadi (4)

1. Aquatic Resource Management Doctoral Program, Faculty of Fisheries and Marine Sciences,
Diponegoro University, Semarang 50275, Indonesia. *E-mail: dkresnasari@gmail.com
2. Department of Oceanography, Faculty of Fisheries and Marine Sciences, Diponegoro
University, Semarang 50275, Indonesia. E-mail: muhammadzainuri1962@gmail.com
3. Department of Aquatic Resources, Faculty of Fisheries and Marine Sciences, Diponegoro
University, Semarang 50275, Indonesia. E-mail: maxmuskananfola@lecturer.undip.ac.id
4. Department of Marine Science, Faculty of Fisheries and Marine Sciences, Diponegoro
University, Semarang 50275, Indonesia. E-mail: rudhipribadi@gmail.com
5. Fisheries Science Study Program, Faculty of Science and Technology, Nahdaltul Ulama
Purwokerto University, Purwokerto 53145, Indonesia.
 

Mangrove biomass production is influenced by both structural attributes and leaf level physiological processes. However, empirical field studies linking these components at the stand scale remain limited. This study explored associations among leaf chlorophyll content, foliar damage, biomass accumulation of Sonneratia caseolaris (L.) Engl., and sediment nutrient conditions in the Segara Anakan Mangrove Lagoon, Indonesia. Three sampling stations were established, and field surveys were conducted from May to June 2023. Aboveground and belowground biomass were estimated using established species-specific allometric equations. Chlorophyll concentrations were determined spectrophotometrically, and foliar damage was quantified by the Bioleaf application on a smartphone. Positive associations were observed between biomass estimates and chlorophyll concentrations in both intact and partially damaged leaves, reflecting potential photosynthetic capacity. However, correlation analyses were based on plot-level data (n = 15) with limited replication. Therefore, the results should be interpreted as indicative ecological patterns rather than statistical evidence of causal relationships. Stations with relatively higher biomass also exhibited higher sediment nitrogen concentrations, suggesting a possible role of nutrient availability in supporting structural growth. Despite a high proportion of visibly damaged leaves across stations, measurable chlorophyll levels were maintained, indicating that partial tissue damage does not necessarily correspond to complete physiological impairment. Overall, the findings suggest that leaf-level physiological indicators may contribute to understanding spatial variability in mangrove biomass when interpreted within ecological and methodological constraints. Integrating structural and physiological measurements may support improved assessment of mangrove condition in dynamic estuarine environments.

Received: 24 December 2025 / Accepted: 06 March 2026 / Available online: 12 March 2026

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.

Victor Valdayskikh, Olga Nekrasova*, and Tatiana Radchenko

Department of Earth and Space Science, Ural Federal University, 48 Kuibysheva Str., 620043
Yekaterinburg, Russia. E-mails: v_vald@mail.ru (VV), o_nekr@mail.ru* (ON), tatiana.radchenko@urfu.ru (TR)

Challenges of our time require in-depth studies of the carbon cycle and, consequently,  information about its stocks in soils. Soils play a leading role in the sequestration and emission of carbon. Boreal forests account for nearly 30 % of Earth’s forests. Therefore, the purpose of this study was to establish the features of carbon accumulation in the soils of the southern taiga area within the territory of the supersite ‘Ural-Carbon’ in the Sverdlovsk Region, in the Urals. Geobotanical studies of a profile across the watershed and terrace showed that, despite the similarity in the floral composition and structure of forest communities, with a predominance of dark coniferous trees, there are more spruce trees in the upper site of the studied profile. Additionally, there is an increased proportion of tallgrass species. The soils exposed in 24 pits were classified as Luvisols with a high proportion of clay particles in the particle size distribution. The stocks of organic carbon in the supersite, determined based on the bulk density values obtained for each individual profile, were 9.06 ±3.86 t·ha-1 for the litter layer, 78.11 ±22.41 t·ha-1 for the upper 0–30 cm layer, 96.22 ±30.9 t·ha-1 for 0–50 cm layer, and 111.06 ±37.5 t·ha-1 for 0–100 cm layer. At the same time, soils in the lower site of the profile had significantly higher carbon content compared to those in the upper site, and the differences were statistically significant for the mineral horizons. Obtained data on carbon stocks indicate the heterogeneity of the soil cover and are generally consistent with the available estimates for soils in dark coniferous forests in other regions. These data can be used to create models of carbon stocks in old-growth southern taiga dark conifer forests that form in similar conditions, as well as for climate projects.

Received: 29 December 2025 / Accepted: 18 March 2026 / Available online: 16 April 2026

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.

Ivanna Kulbanska (1)*, Maryna Shvets (2), Anatolii Goychuk (1), Vasyl Zayachuk (3), and Nataliya Horbenko (3)

1. National University of Life and Environmental Sciences of Ukraine 03041, 15 Heroiv Oborony Str., Kyiv, Ukraine. *E-mail: i_kulbanska@ukr.net
2. Polissia National University, 10008, 7 Staryi Blvd., Zhytomyr, Ukraine.
3. National University of Forestry and Wood Technology 79057, 103 General Chuprynky Str., Lviv, Ukraine.

This study investigates the development of transverse oak canker, examines key factors influencing its spread, and evaluates potential ecosystem threats. The results provide a basis for developing recommendations for monitoring and preserving oak stands within Kyiv region of Ukraine. During the study, typical symptoms of tree damage were described, confirming three types of lesion morphogenesis: open, transitional, and closed. A gradation analysis was conducted based on trunk diameter and the number of cankers detected. It was established that the highest proportion of trees with minor damage occurred in the 12–32 cm diameter class, where this indicator exceeded 50.0 %. In trees with a diameter of 48–56 cm, a consistently high level of minor damage was maintained alongside a low share of severe damage (up to 13.0 %), suggesting potential genetic resistance or adaptive defence mechanisms in older age groups. Conversely, the smallest trees (4–8 cm) exhibited the highest percentage of medium and severe damage, indicating a high vulnerability in young plants. The results demonstrate that the severity of oak canker damage is closely correlated with trunk diameter and tree age – factors that must be considered when developing monitoring, prevention, and control strategies.

Received: 08 February 2026 / Accepted: 31 March 2026 / Available online: 16 April 2026

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.

Muh Iriansyah Akram, Andang Suryana Soma*, and Baharuddin Baharuddin

Department of Forestry, Faculty of Forestry, Hasanuddin University, Tamalanrea Campus,
Jalan Perintis Kemerdekaan Km. 10, Makassar 90245, Indonesia. *E-mail: s_andangs@unhas.ac.id
 

Rapid land-cover change in Tallo Watershed, driven by urbanisation and population growth, has intensified environmental degradation. This has increased drought risk, particularly under ongoing climate change and growing pressure on water resources. This study aims to assess spatial drought conditions and formulate adaptive land-use directions in Tallo Watershed. Landsat 8 OLI/ TIRS imagery from 2014 and 2023 was analysed using a band combination of SWIR-1 (band 6), NIR (band 5), and Red (band 4), and drought conditions were evaluated using Normalised Difference Latent Heat Index (NDLI) as primary spatial indicator. Standardised Precipitation Evapotranspiration Index (SPEI) was applied as a climatic classification framework to support interpretation of NDLI-derived drought severity. The results indicate a clear increase in drought-affected areas, reaching 1,253 ha between 2014 and 2023, with distinct spatial patterns across upstream, midstream, and downstream zones. Land-cover change was dominated by expansion of settlements (+1,964 ha) and reduction of rice fields (−1,699 ha), reflecting rapid urban development. Areas experiencing intensive land-cover conversion consistently corresponded with higher drought severity, highlighting strong influence of anthropogenic land transformation on drought dynamics. Compared with recent studies that primarily focus on meteorological drought indicators, this study demonstrates added value of integrating remote sensing-based NDLI for capturing spatial variations in drought linked to land-cover change. Based on drought levels and regional biophysical characteristics, adaptive land-use directives were developed to enhance resilience to climate change. Findings provide critical spatial information for watershed management and adaptive land-use planning in rapidly urbanising regions.

Received: 25 August 2025 / Accepted: 02 April 2026 / Available online: 16 April 2026 

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.