The impact of radioactive contamination on tree regeneration and forest development in the Chernobyl Exclusion Zone

This paper demonstrates the environmental impacts of the wildfires occurring at the beginning of April 2020 in and around the highly contaminated Chernobyl Exclusion Zone (CEZ). Due to the critical fire location, concerns arose about secondary radioactive contamination potentially spreading over Europe. The impact of the fire was assessed through the evaluation of fire plume dispersion and re-suspension of the radionuclide Cs-137, whereas, to assess the smoke plume effect, a WRF-Chem simulation was performed and compared to Tropospheric Monitoring Instrument (TROPOMI) satellite columns. The results show agreement of the simulated black carbon and carbon monoxide plumes with the plumes as observed by TROPOMI, where pollutants were also transported to Belarus. From an air quality and health perspective, the wildfires caused extremely bad air quality over Kiev, where the WRF-Chem model simulated mean values of PM2.5 up to 300 µg/m3 (during the first fire outbreak) over CEZ. The re-suspension of Cs-137 was assessed by a Bayesian inverse modelling approach using FLEXPART as the atmospheric transport model and Ukraine observations, yielding a total release of 600 ± 200 GBq. The increase in both smoke and Cs-137 emissions was only well correlated on the 9 April, likely related to a shift of the focus area of the fires. From a radiological point of view even the highest Cs-137 values (average measured or modelled air concentrations and modelled deposition) at the measurement site closest to the Chernobyl Nuclear Power Plant, i.e., Kiev, posed no health risk.

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Effects of open-range cattle grazing on deciduous tree regeneration, damage, and mortality following patch logging

Canadian Journal of Forest Research ◽

10.1139/cjfr-2014-0131 ◽

2014 ◽

Vol 44 (7) ◽

pp. 777-783 ◽

Cited By ~ 9

Author(s):

Jillian Kaufmann ◽

Edward W. Bork ◽

Michael J. Alexander ◽

Peter V. Blenis

Keyword(s):

Populus Tremuloides ◽

Sustainable Forest Management ◽

Deciduous Forest ◽

Total Mortality ◽

Cattle Grazing ◽

Tree Regeneration ◽

Deciduous Tree ◽

Populus Balsamifera ◽

Haul Road ◽

The Impact

The impact of summer cattle grazing on deciduous tree regeneration within uncut forests, clearcuts, partially harvested areas, and in-block haul road habitats was examined in four experimental pastures of central Alberta during 2008 and 2009. Sampling of 233 field plots, both inside and outside cattle exclosures, was used to document sapling densities, height, and type of damage. Tree densities (primarily aspen (Populus tremuloides Michx.)) differed among habitats but less so with exposure to cattle. Densities were greatest in clearcuts, followed by partially harvested areas and then uncut forest and haul roads. While exposure to cattle reduced total tree regeneration, sapling densities and sizes remained sufficient to meet postharvest standards for deciduous forest regeneration in Alberta, even with exposure to cattle. Cattle damage in harvested areas was primarily from browsing (≤3.2% of saplings), with proportionally more trees affected in uncut forests (8.6%). Browsing was particularly high on balsam poplar (Populus balsamifera L.) (25%) during 2008. Although sapling damage increased with high cattle stocking in 2008 (to 10.5%), total mortality was limited to 15.5% through 2009. These findings show that despite cattle impacts to some saplings, damage levels were insufficient to alter deciduous regeneration, highlighting the compatibility of cattle grazing and sustainable forest management on public lands in this region.

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Impact of forest fire on the vegetable cover of radioactively contaminated areas

Agroecological journal ◽

10.33730/2077-4893.1.2021.227241 ◽

2021 ◽

pp. 68-80

Author(s):

V. Landin ◽

O. Tishchenko ◽

V. Gurelia ◽

T. Kuchma ◽

V. Feshchenko

Keyword(s):

Remote Sensing ◽

Spectral Data ◽

Nature Reserve ◽

Dry Forest ◽

Exclusion Zone ◽

Space Images ◽

The Earth ◽

Drainage Canals ◽

The Impact ◽

Artificial Reservoirs

This article presents the results of assessing the impact of fires on the vegetation of the Chernobyl Exclusion Zone and the zone of unconditional (mandatory) resettlement, Drevlyansky Nature Reserve using means of remote sensing of the Earth for the period from 1986 to 2020. The methods and criteria for assessing vegetation damage using spectral data obtained from space satellites of the Earth and using methods of geoinformation technologies are proposed. This methodology provides mapping vegetation through remote sensing imagery. Comparing space images of the territory of the exclusion zone and the zone of unconditional mandatory resettlement for 1986, 1999, 2013, 2017, 2018, 2019, 2020, for the period of 34 years after the accident, identified significant changes in the condition of lands belonging to forest and agricultural lands. In the result of the study revealed the changes observed in the boundaries of water bodies because drying of artificial reservoirs, changes in the direction of riverbeds, waterlogging of drainage canals and adjacent forest areas. The identified effect from fires in forests where dry forest materials have accumulated and from consequences of forest management. It is also noted, that according to the spectral data of space images, areas of forest damaged by insects are well defined. The study reveals

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Reference indicators enabling preliminary evaluations of the impact of radioactive releases on agricultural products

10.5194/egusphere-egu21-474 ◽

2021 ◽

Author(s):

Barbara Ferrucci ◽

Chiara Telloli

Keyword(s):

Radioactive Contamination ◽

Food Chain ◽

Geographic Area ◽

Agricultural Products ◽

Accurate Estimation ◽

Specific Reference ◽

Main Concern ◽

Relative Significance ◽

Human Dose ◽

The Impact

<p>After the release of high levels of radioactivity into the environment, one of the main concern relates the contamination foodstuffs. In some exposure scenarios the transfer of radionuclides through the food chain to consumers represents a major contribution to human dose. Therefore an accurate estimation of radionuclide activity concentrations in agricultural products is crucial to evaluate the ingestion dose to the population consuming locally produced food. There are many mechanisms contributing to the radioacive contamination of agricultural products as interception, retention, absorption and translocation, due to mechanisms as deposition to the exposed plant surfaces, and/or root uptake. In the last decades several efforts have been spent in developing mathematical models to predict the potential transfers of radionuclides in plants and their concentration in the edible parts. Nevertheless the relative significance of each pathway depends on a large amount of variables and parameters that increase the complexity of the models, moreover the lack of expermental data, often limit the possibility to make any meaningful results. The main aspect that make difficult to predict the uptake of radionuclides by plants is the dynamic nature of the contamination scenarios due primarly to the the growing of plants. Nevertheless, there are some factors that can be considered as &#8216;static&#8217; for each specific geographic area, and each specific radionuclide, as the soil characteristics, the type of crop, and the behavour of some radionuclides in the environment. In the framework of a preliminary safety assessment of a radioactive release scenario, these factors could be taken as reference indicators of the potential impact on the local human food chain radioactive contamination. In this work we focus on the analysis of the scientific literature pertaining to all experimntal studies in radionuclide plant uptake, from 2000 to 2020. The aims of this analysis is to collect set of some characteristics allowing to classify, in a macroscopic scale, specific reference indicators that most contribute to the radioactive contamination of agricultural products in different geographyc areas.</p>

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Features of the formation of the system of agricultural land use in conditions of radioactive contamination

10.33920/vne-03-2109-04 ◽

2021 ◽

pp. 28-33

Author(s):

Irina Gennadievna Makarova

Keyword(s):

Land Use ◽

Radioactive Contamination ◽

Systematic Approach ◽

Agricultural Land ◽

Import Substitution ◽

Agricultural Land Use ◽

Land Utilization ◽

The Impact

In light of the growing interest in the problem of food import substitution in the EEU member countries the topic of the formation of the system of agricultural land in conditions of radioactive contamination is particularly topical. The paper presents a systematic approach to look at agricultural land utilization. The impact of radioactive contamination on changing the territorial land utilization system is analysed.

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Long-term effects of stump removal and tree species composition on the diversity and structure of soil fungal communities

FEMS Microbiology Ecology ◽

10.1093/femsec/fiaa061 ◽

2020 ◽

Vol 96 (5) ◽

Author(s):

Dixi Modi ◽

Suzanne Simard ◽

Jean Bérubé ◽

Les Lavkulich ◽

Richard Hamelin ◽

...

Keyword(s):

Species Composition ◽

Fungal Community ◽

Tree Species ◽

Management Practice ◽

Tree Regeneration ◽

Root Disease ◽

Fungal Communities ◽

Tree Species Composition ◽

The Impact

ABSTRACT Stump removal is a common forest management practice used to reduce the mortality of trees affected by the fungal pathogen-mediated root disease, Armillaria root rot, but the impact of stumping on soil fungal community structure is not well understood. This study analyzed the long-term impact of stumping and tree species composition on the abundance, diversity and taxonomic composition of soil fungal communities using internal transcribed spacer (ITS) marker-based DNA metabarcoding in a 48-year-old trial at Skimikin, British Columbia. A total of 108 samples were collected from FH (fermented and humus layers), and soil mineral horizons (A and B) from stumped and unstumped plots of six tree species treatments (pure stands and admixtures of Douglas-fir, western red-cedar and paper birch). Fungal α-diversity in the A horizon significantly increased with stumping regardless of tree species composition, while β-diversity was significantly affected by stumping in all the horizons. We also observed that the relative abundance of the saprotrophic fungal community declined while that of the ectomycorrhizal fungal community increased with stumping. In conclusion, increase in ectomycorrhizal fungal associations, which are positively associated with tree productivity, suggests that stumping can be considered a good management practice for mitigating root disease and promoting tree regeneration.

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Short-term effects of cut-to-length versus full-tree harvesting on conifer regeneration in jack pine, mixedwood, and black spruce forests in Manitoba

Canadian Journal of Forest Research ◽

10.1139/x04-064 ◽

2004 ◽

Vol 34 (9) ◽

pp. 1938-1945 ◽

Cited By ~ 13

Author(s):

Isobel Waters ◽

Steven W Kembel ◽

Jean-François Gingras ◽

Jennifer M Shay

Keyword(s):

Picea Mariana ◽

Picea Glauca ◽

Pinus Banksiana ◽

Black Spruce ◽

Abies Balsamea ◽

Jack Pine ◽

Tree Regeneration ◽

Understorey Vegetation ◽

Advance Regeneration ◽

The Impact

This study compares the effects of full-tree versus cut-to-length forest harvesting methods on tree regeneration in jack pine (Pinus banksiana Lamb.), mixedwood (Picea glauca (Moench) Voss Populus tremuloides Michx. Abies balsamea (L.) Mill.), and black spruce (Picea mariana (Mill.) BSP) sites in southeastern Manitoba, Canada. We surveyed tree regeneration densities, disturbance characteristics, and understorey vegetation in replicated control and harvested plots in each site type preharvest (1993) and 1 and 3 years postharvest (1994, 1996). In jack pine sites, the full-tree harvest method promoted regeneration of Pinus banksiana through increased disturbance of soil and the moss layer, and decreased slash deposition relative to the cut-to-length method. Conversely, in mixedwood sites the cut-to-length method resulted in less damage to advance regeneration and proved better at promoting postharvest regeneration of Abies balsamea and Picea glauca relative to the full-tree method. In black spruce sites, there were few differences in the impact of the two harvesting methods on regeneration of Picea mariana, which increased in frequency and density after both types of harvesting.

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The influence of the bamboo Yushania microphylla on regeneration of Abies densa in central Bhutan

Canadian Journal of Forest Research ◽

10.1139/x99-125 ◽

1999 ◽

Vol 29 (10) ◽

pp. 1518-1527 ◽

Cited By ~ 16

Author(s):

G Gratzer ◽

P B Rai ◽

G Glatzel

Keyword(s):

Forest Floor ◽

Height Growth ◽

Tree Regeneration ◽

Average Height ◽

Seedling Density ◽

Tree Seedling ◽

Term Survival ◽

Light Levels ◽

Gap Fraction ◽

The Impact

To assess the impact of a dense understory of the bamboo Yushania microphylla Munro on tree regeneration in monospecific Abies densa Griff. stands of the central Bhutan Himalayas, the age-class distribution of fir regeneration, the microsite preferences, and height growth as well as the relationship between height of the bamboo, gap fraction, and tree seedling density were studied. Seedling densities were much lower on sites with bamboo. Recruitment was more or less continuous, and there was no indication of overall synchronized single-cohort regeneration in bamboo plots. On sites with bamboo understory, the light regime at the forest floor is strongly influenced by the height of the bamboo. A large portion of the variance of tree seedling density could be explained by the height of the bamboo. The mortality of fir seedlings is considerably reduced at elevated microsites. Fir establishment on the forest floor is restricted to sites where bamboo density is low and light levels are higher. On sites with dense, unbrowsed bamboo, light levels are too low for long-term survival of fir seedlings, resulting in a lack of suppressed regeneration with minimal height growth. Because of the absence of this fraction, the average height increment of fir seedlings is higher on sites with bamboo.

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