Extracting DNA from soil or directly from isolated nematodes indicate dissimilar community structure for Europe-wide forest soils

Nematodes are numerous in soils and play a crucial role in soil food-webs. DNA metabarcoding offers a time-effective alternative to morphology-based assessments of nematode diversity. However, it is unclear how different DNA extraction methods prior to metabarcoding could affect community analysis. We used soils with woody vegetation from a European latitudinal gradient (29 sites, 39 to 79°N, ∼4500 km, covering six biomes) to systematically evaluate the effect of two sources of nematode DNA either directly extracted from soils vs. extracted from nematodes previously isolated from soils hypothesizing that the DNA source material may produce different diversities, community structures and abundances of feeding types. Nematode-sample DNA exhibited a higher richness, while no difference in Shannon diversity was found between the approaches. The DNA sources also created significantly different community structures, with greater differences observed across soil-extracted DNA than nematode-sample DNA. The most overrepresented species in nematode-sample DNA were Heterocephalobus elongatus, Eucephalobus striatus and Hexatylus sp., whereas Phasmarhabditis sp. and Eumonhystera filiformis were overrepresented in soil-extracted DNA. Read abundances of feeding types significantly differed between the DNA sources and across sites, with a significant effect of biome on both ecto- and endoparasitic herbivores in soil-extracted DNA and for ectoparasitic herbivores only in nematode-sample DNA. Collectively, our data suggest that choice of the DNA source material may lead to different patterns of nematode community composition across space and environmental conditions. Improving the sensitivity of the soil-extracted DNA method by developing protocols using larger amounts of soil and designing nematode-specific primers will make this approach an efficient screening tool to analyse nematode diversity and community structure complementing the labour-intensive isolation of intact nematodes from soils (nematode-sample DNA)

Investigation of post-fire natural regeneration in forest plantations of Pinus sylvestris and Larix decidua on the Northern slopes of Rila mountain

Wildfires alter both the vegetation and the soil properties, thus changing the conditions of their regeneration. Each year, forest fires impact significant areas within the lower forest zone, where the coniferous plantations, especially Scots pine plantations are deteriorated. The natural forest recovery processes in fire-affected areas are still insufficiently studied in Bulgaria. Therefore, the aim of the present study was to investigate the possibility of a natural post-fire regeneration of forest vegetation and the conditions, under which it was limited. The natural regeneration of coniferous plantations in the area of Dolna Banya (The Northern slopes of Rila Mt) with dominant tree species of Scots pine (Pinus sylvestris L.) (Object 1) and European larch (Larix decidua Mill.) (Object 2) was studied four years after fire and was found to depend on the slope aspect, the micro-relief and soil humidity. It was found that on the South-western slopes, the diversity of broadleaves tree species recovery (birch, oak, sallow, aspen) was higher in comparison with the coniferous (Scotch pine) ones. On the Eastern slope, the regeneration of coniferous prevailed over that of broadleaves. On the ridges, the regeneration was the lowest one, while on the foot of the slopes was higher

New earthworm (Clitellata: Lumbricidae) records from Vitosha Mts. (Bulgaria)

The paper deals with earthworm diversity from Vitosha Mountain (Bulgaria). During the investigation 10 earthworm species were collected altogether, belonging to 7 genera. Among them, two taxa are reported for the first time from the explored region. Aporrectodea caliginosa (Savigny, 1826) and Lumbricus terrestris Linnaeus, 1758 are proved to be new records from the territory of Vitosha Mountain

Integrated Evaluation of Vegetation Drought Stress through Satellite Remote Sensing

In the coming decades, Bulgaria is expected to be affected by higher air temperatures and decreased precipitation, which will significantly increase the risk of droughts, forest ecosystem degradation and loss of ecosystem services (ES). Drought in terrestrial ecosystems is characterized by reduced water storage in soil and vegetation, affecting the function of landscapes and the ES they provide. An interdisciplinary assessment is required for an accurate evaluation of drought impact. In this study, we introduce an innovative, experimental methodology, incorporating remote sensing methods and a system approach to evaluate vegetation drought stress in complex systems (landscapes and ecosystems) which are influenced by various factors. The elevation and land cover type are key climate-forming factors which significantly impact the ecosystem’s and vegetation’s response to drought. Their influence cannot be sufficiently gauged by a traditional remote sensing-based drought index. Therefore, based on differences between the spectral reflectance of the individual natural land cover types, in a near-optimal vegetation state and divided by elevation, we assigned coefficients for normalization. The coefficients for normalization by elevation and land cover type were introduced in order to facilitate the comparison of the drought stress effect on the ecosystems throughout a heterogeneous territory. The obtained drought coefficient (DC) shows patterns of temporal, spatial, and interspecific differences on the response of vegetation to drought stress. The accuracy of the methodology is examined by field measurements of spectral reflectance, statistical analysis and validation methods using spectral reflectance profiles

Risk of flooding: Activities, parameters and regional peculiarities, Case study: Varbitsa watershed basin, Bulgaria

An overview of the activities overtaken during risk of flooding situations, in one of the more often flooding region - the watershed of Varbitsa river (Southeastern part of Bulgaria) - has been performed. The main cognitive parameters for risk perception and risk definition, depending on regional, social and historical factors have been examined. The existing information and instructions for mass media communication in relation to the process of interaction in a disaster situation have been discussed. In connection to determination of the risky segments in the basin and plans for announcement, the prevention communication measures have been outlined. On the basis of the Bulgarian normative legislation, the activities concerning organization of communications in a risk-of-disaster situation and mutual aid between authorities, which are part of the Integrated Help System have been indicated. It has been accented on the necessity of a more effective realization of the action plans during natural disasters and especially flooding, in order to improve the partnership between authorities and participants in the communication process during risk-of-flooding situations

Post-Fire Forest Vegetation State Monitoring through Satellite Remote Sensing and In Situ Data

Wildfires have significant environmental and socio-economic impacts, affecting ecosystems and people worldwide. Over the coming decades, it is expected that the intensity and impact of wildfires will grow depending on the variability of climate parameters. Although Bulgaria is not situated within the geographical borders of the Mediterranean region, which is one of the most vulnerable regions to the impacts of temperature extremes, the climate is strongly influenced by it. Forests are amongst the most vulnerable ecosystems affected by wildfires. They are insufficiently adapted to fire, and the monitoring of fire impacts and post-fire recovery processes is of utmost importance for suggesting actions to mitigate the risk and impact of that catastrophic event. This paper investigated the forest vegetation recovery process after a wildfire in the Ardino region, southeast Bulgaria from the period between 2016 and 2021. The study aimed to present a monitoring approach for the estimation of the post-fire vegetation state with an emphasis on fire-affected territory mapping, evaluation of vegetation damage, fire and burn severity estimation, and assessment of their influence on vegetation recovery. The study used satellite remotely sensed imagery and respective indices of greenness, moisture, and fire severity from Sentinel-2. It utilized the potential of the landscape approach in monitoring processes occurring in fire-affected forest ecosystems. Ancillary data about pre-fire vegetation state and slope inclinations were used to supplement our analysis for a better understanding of the fire regime and post-fire vegetation damages. Slope aspects were used to estimate and compare their impact on the ecosystems’ post-fire recovery capacity. Soil data were involved in the interpretation of the results

Knowledge synthesis for environmental decisions : an evaluation of existing methods, and guidance for their selection, use and development : a report from the EKLIPSE project

Environmental governance in context: a study of process dynamics, contextual features and outcomes in four empirical case

What does the science say? The diversity of methods to synthesize knowledge

Effective, unbiased and transparent methods of knowledge synthesis are a crucial element of science-policy-society interactions. A vast and rapidly expanding body of knowledge is relevant to many policy decisions. This includes scientific knowledge, technical know-how and experiential knowledge held by experts, and indigenous and local knowledge. Synthesizing knowledge within timescales relevant to policy makers is a real challenge, but many methods are now available to do so. We have identified 21 knowledge synthesis methods that could be used to answer questions from policymakers or other stakeholders [1]. It is not an exhaustive list, but those we consider most useful for current science-policy-society interfaces in environment and natural resource management. The methods range from focus groups, which can be done in just a few days and gather local place-based knowledge, including opinions and values from small groups; to structured systematic reviews, which follow an a priori protocol, can take a year or more, require substantial scientific expertise to complete and address a narrow, well-defined scientific question. The methods can draw on different sources of tacit or codified knowledge: scientific, indigenous and local knowledge, technical know-how, and anecdotal evidence. We have developed concise guidance on each method, providing information on how it works, what it can achieve, what type of questions can be tackled, how much it costs, and what specialist resources are required. The guidance also summarises the relative strengths and weaknesses of each method. We have collected example case studies to illustrate the use of each of the different methods to inform design or implementation of environmental policies across Europe. Building on previous work [2,3], and in partnership with policymakers, we have devised a process for structured dialogue between knowledge-holders and knowledge requesters, to select an appropriate knowledge synthesis methods or set of methods. This talk provides an overview of the methods and describes the method selection process, using recent examples from the EKLIPSE project (www.eklipse-mechanism.eu/). References [1] Dicks, L. V., Haddaway, N., Hernández-Morcillo, M., Mattsson, B., Randall, N., Failler, P., . . . Wittmer, H. (2017). Knowledge synthesis for environmental decisions: an evaluation of existing methods, and guidance for their selection, use and development – a report from the EKLIPSE project. [2] Pullin, A., Frampton, G., Jongman, R. et al. (2016) Selecting appropriate methods of knowledge synthesis to inform biodiversity policy. Biodiversity and Conservation 25: 1285. [3] Cook, C. N., Nichols, S. J., Webb, J. A., Fuller, R. A., & Richards, R. M. (2017). Simplifying the selection of evidence synthesis methods to inform environmental decisions: A guide for decision makers and scientists. Biological Conservation, 213, Part A, 135-145.peerReviewe

Extracting DNA from soil or directly from isolated nematodes indicate dissimilar community structure for Europe-wide forest soils

Nematodes are numerous in soils and play a crucial role in soil food-webs. DNA metabarcoding offers a timeeffective alternative to morphology-based assessments of nematode diversity. However, it is unclear how different DNA extraction methods prior to metabarcoding could affect community analysis. We used soils with woody vegetation from a European latitudinal gradient (29 sites, 39 to 79 degrees N, similar to 4500 km, covering six biomes) to systematically evaluate the effect of two sources of nematode DNA either directly extracted from soils vs. extracted from nematodes previously isolated from soils hypothesizing that the DNA source material may produce different diversities, community structures and abundances of feeding types. Nematode-sample DNA exhibited a higher richness, while no difference in Shannon diversity was found between the approaches. The DNA sources also created significantly different community structures, with greater differences observed across soil-extracted DNA than nematode-sample DNA. The most overrepresented species in nematode-sample DNA were Heterocephalobus elongatus, Eucephalobus striatus and Hexatylus sp., whereas Phasmarhabditis sp. and Eumonhystera filiformis were overrepresented in soil-extracted DNA. Read abundances of feeding types signifi-cantly differed between the DNA sources and across sites, with a significant effect of biome on both ecto-and endoparasitic herbivores in soil-extracted DNA and for ectoparasitic herbivores only in nematode-sample DNA. Collectively, our data suggest that choice of the DNA source material may lead to different patterns of nematode community composition across space and environmental conditions. Improving the sensitivity of the soil -extracted DNA method by developing protocols using larger amounts of soil and designing nematode-specific primers will make this approach an efficient screening tool to analyse nematode diversity and community structure complementing the labour-intensive isolation of intact nematodes from soils (nematode-sample DNA).Peer reviewe