scholarly journals Long time no see – rediscovery of peculiar ephemeral fern Anogramma leptophylla (L.) Link in Croatia

2017 ◽  
Vol 76 (1) ◽  
pp. 91-94
Author(s):  
Vedran Šegota ◽  
Vladimir Hršak ◽  
Antun Alegro
Keyword(s):  
Environmental Conditions ◽  
Mediterranean Climate ◽  
Balkan Peninsula ◽  
Small Population ◽  
Life Strategy ◽  
Soil Humidity ◽  
Long Time ◽  
Fern Species

Abstract Anogramma leptophylla is one of the rarest fern species in Balkan Peninsula. In Croatia, several localities were noted prior to this study, when its presence was confirmed with a discovery of a small population on the island of Mljet (Southern Adriatic). This was, after almost 80 years, the first reliable finding of this species along Eastern Adriatic. The establishment of A. leptophylla on the western part of the island of Mljet may be attributable to certain favourable environmental conditions, but essentially to higher air and soil humidity. Its unusual bryophyte-like life strategy, with short-living annual sporophytes, facilitates its survival under Mediterranean climate, generally unfavourable for pteridophytes.

scholarly journals Long time no see – rediscovery of peculiar ephemeral fern Anogramma leptophylla (L.) Link in Croatia

2016 ◽  
Vol 0 (0) ◽  
Author(s):  
Vedran Šegota ◽  
Vladimir Hršak ◽  
Antun Alegro
Keyword(s):  
Environmental Conditions ◽  
Mediterranean Climate ◽  
Balkan Peninsula ◽  
Small Population ◽  
Life Strategy ◽  
Soil Humidity ◽  
Long Time ◽  
Fern Species

Abstract Anogramma leptophylla is one of the rarest fern species in Balkan Peninsula. In Croatia, several localities were noted prior to this study, when its presence was confirmed with a discovery of a small population on the island of Mljet (Southern Adriatic). This was, after almost 80 years, the first reliable finding of this species along Eastern Adriatic. The establishment of A. leptophylla on the western part of the island of Mljet may be attributable to certain favourable environmental conditions, but essentially to higher air and soil humidity. Its unusual bryophyte-like life strategy, with short-living annual sporophytes, facilitates its survival under Mediterranean climate, generally unfavourable for pteridophytes.

scholarly journals Genetic and no genetic variability of two-year old seedlings of 13 hybrid plane half-sib lines

2005 ◽  
pp. 69-85 ◽  
Author(s):  
Radmila Knezevic ◽  
Mirjana Sijacic-Nikolic
Keyword(s):  
Genetic Variability ◽  
Environmental Conditions ◽  
Hybrid Sterility ◽  
Soil Humidity ◽  
Frequent Mutations ◽  
Different Levels ◽  
Partial Hybrid

This paper presents the results of the analysis of variability of 8 analyzed morph metric parameters in two-year old seedlings of 13 half-sib lines at different levels. The recorded genetic and no genetic variability is conditioned by numerous different factors. The important causes of genetic variability are: partial incompatibility of parent trees, partial hybrid sterility, predominant inbreeding, frequent mutations with the growth of parent trees, very abundant gene recombination's, etc. The causes of no genetic seedling variability are: external environmental conditions (soil humidity, conditions of cultivation, sylvotechnical interventions, etc) and the internal or the somatic environment of seedling.

scholarly journals ‘Pre-Neolithic’ in Southeast Europe: a Bulgarian perspective

2014 ◽  
Vol 41 ◽  
pp. 95-109 ◽  
Author(s):  
Maria Gurova ◽  
Clive Bonsall
Keyword(s):  
Black Sea ◽  
Resource Availability ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Balkan Peninsula ◽  
The Black Sea ◽  
Future Research ◽  
Upper Palaeolithic ◽  
Southeast Europe ◽  
Site Distribution

 This paper discusses why large areas of the central and northern Balkans lack evidence of Mesolithic settlement and what implications this holds for future research into the Neolithization of the region. A marked shift in site distribution patterns between Upper Palaeolithic and Mesolithic is interpreted as a response to changing environmental conditions and resource availability. It is suggested that some important questions of the pattern, processes and timing of the transition to farming across the Balkan Peninsula may only be answered through new archaeological surveys of the Lower Danube valley and exploration of submerged landscapes along the Black Sea, Aegean and Adriatic coasts.

Comparison of the Environmental Contour Method and Response-Based Analysis Using Response Emulator for Estimating Extreme Ship Responses

2019 ◽  
Author(s):  
Erik Vanem ◽  
Bingjie Guo
Keyword(s):  
Time Series ◽  
Environmental Conditions ◽  
Structural Response ◽  
Bending Moment ◽  
Contour Method ◽  
Extreme Value Analysis ◽  
Value Analysis ◽  
Long Time Series ◽  
Long Time ◽  
Extreme Responses

Abstract Environmental contours are often applied in probabilistic structural reliability analysis to identify extreme environ-mental conditions that may give rise to extreme loads and responses. They facilitate approximate long term analysis of critical structural responses in situations where computationally heavy and time-consuming response calculations makes full long-term analysis infeasible. The environmental contour method identifies extreme environmental conditions that are expected to give rise to extreme structural response of marine structures. The extreme responses can then be estimated by performing response calculations for environmental conditions along the contours. Response-based analysis is an alternative, where extreme value analysis is performed on the actual response rather than on the environmental conditions. For complex structures, this is often not practical due to computationally heavy response calculations. However, by establishing statistical emulators of the response, using machine learning techniques, one may obtain long time-series of the structural response and use this to estimate extreme responses. In this paper, the contour method will be compared to response-based estimation of extreme vertical bending moment for a tanker. A response emulator based on Gaussian processes regression with adaptive sampling has been established based on response calculations from a hydrodynamic model. Long time-series of sea-state parameters such as significant wave height and wave period are used to construct N-year environmental contours and the extreme N-year response is estimated from numerical calculations for identified sea states. At the same time, the response emulator is applied on the time series to provide long time-series of structural response, in this case vertical bending moment of a tanker. Extreme value analysis is then performed directly on the responses to estimate the N-year extreme response. The results from either method will then be compared, and it is possible to evaluate the accuracy of the environmental contour method in estimating the response.

scholarly journals Production of Didymella rabiei Pseudothecia and Dispersal of Ascospores in a Mediterranean Climate

2005 ◽  
Vol 95 (11) ◽  
pp. 1279-1286 ◽  
Author(s):  
E. Gamliel-Atinsky ◽  
D. Shtienberg ◽  
H. Vintal ◽  
Y. Nitzni ◽  
A. Dinoor
Keyword(s):  
Low Temperature ◽  
Environmental Conditions ◽  
Low Temperatures ◽  
Mediterranean Climate ◽  
Temperature Requirement ◽  
Trap Plants ◽  
Series Of Experiments ◽  
The Mediterranean ◽  
Stem Segments

Temperature and wetness conditions required for development and maturation of Didymella rabiei pseudothecia were determined in a series of experiments conducted in controlled-environmental conditions. Initial stages of pseudothecium formation occurred at temperatures ranging from 5 to 15°C. Incubation at low temperatures was essential for subsequent pseudothecium maturation. This requirement was satisfied for chickpea stem segments incubated at 5 or 10°C for three consecutive weeks or during periods of 3 or 5 days, separated by periods at higher temperatures. Following the low-temperature requirement, subsequent pseudothecium development was independent of temperature in the range tested (5 to 20°C). Wetness was essential for pseudothecium production: pseudothecia formed and matured on stem segments maintained continuously wet but also on those exposed to periods of three or five wet days, separated by dry periods. The dispersal of D. rabiei ascospores was studied using chickpea plants as living traps in the field. Trap plants were infected mainly when exposed during rain but also in rainless periods. Results of this study enabled us to describe the developmental events leading to the production of the teleomorph stage and the dispersal of ascospores by D. rabiei in the Mediterranean climate of Israel.

scholarly journals Long time series of daily evapotranspiration in China based on the SEBAL model and multisource images and validation

2021 ◽  
Vol 13 (8) ◽  
pp. 3995-4017
Author(s):  
Minghan Cheng ◽  
Xiyun Jiao ◽  
Binbin Li ◽  
Xun Yu ◽  
Mingchao Shao ◽  
...  
Keyword(s):  
Time Series ◽  
Water Resources ◽  
Observational Data ◽  
Water Resources Management ◽  
Environmental Conditions ◽  
Scale Validation ◽  
Point Scale ◽  
Resources Management ◽  
Basin Scale ◽  
Long Time

Abstract. Satellite observations of evapotranspiration (ET) have been widely used for water resources management in China. An accurate ET product with a high spatiotemporal resolution is required for research on drought stress and water resources management. However, such a product is currently lacking. Moreover, the performances of different ET estimation algorithms for China have not been clearly studied, especially under different environmental conditions. Therefore, the aims of this study were as follows: (1) to use multisource images to generate a long-time-series (2001–2018) daily ET product with a spatial resolution of 1 km × 1 km based on the Surface Energy Balance Algorithm for Land (SEBAL); (2) to comprehensively evaluate the performance of the SEBAL ET in China using flux observational data and hydrological observational data; and (3) to compare the performance of the SEBAL ET with the MOD16 ET product at the point scale and basin scale under different environmental conditions in China. At the point scale, both the models performed best in the conditions of forest cover, subtropical zones, hilly terrain, or summer, respectively, and SEBAL performed better in most conditions. In general, the accuracy of the SEBAL ET (rRMSE = 44.91 %) was slightly higher than that of the MOD16 ET (rRMSE = 48.72 %). In the basin-scale validation, both the models performed better than in the point-scale validation, with SEBAL obtaining results superior (rRMSE = 13.57 %) to MOD16 (rRMSE = 32.84 %). Additionally, both the models showed a negative bias, with the bias of the MOD16 ET being higher than that of the SEBAL ET. In the daily-scale validation, the SEBAL ET product showed a root mean square error (RMSE) of 0.92 mm d−1 and an r value of 0.79. In general, the SEBAL ET product can be used for the qualitative analysis and most quantitative analyses of regional ET. The SEBAL ET product is freely available at https://doi.org/10.5281/zenodo.4243988 and https://doi.org/10.5281/zenodo.4896147 (Cheng, 2020a, b). The results of this study can provide a reference for the application of remotely sensed ET products and the improvement of satellite ET observation algorithms.

scholarly journals Different responses to environmental factors in terpene composition of Pinus heldreichii and P. peuce: Ecological and chemotaxonomic considerations

2019 ◽  
Vol 71 (4) ◽  
pp. 629-637
Author(s):  
Nemanja Rajcevic ◽  
Biljana Nikolic ◽  
Petar Marin
Keyword(s):  
Environmental Factors ◽  
Endemic Species ◽  
Environmental Conditions ◽  
Natural Populations ◽  
Balkan Peninsula ◽  
Substrate Type ◽  
Needle Anatomy ◽  
Germacrene D ◽  
Mixed Populations ◽  
Geological Substrate

Many studies show the influence of the environment on terpene composition, but not many of them deal with the terpene composition variability in correlation with environmental factors in Pinus. We chose two endemic species ? P. heldreichii Christ. (Bosnian pine) and P. peuce Griseb. (Macedonian pine) ? two relict and (sub)endemic species of the Balkan peninsula. They mainly form pure stands but can appear in mixed populations, most commonly with each other. These species belong to different subgenera and thus differ greatly, especially in needle anatomy. ?-pinene, limonene and germacrene D predominated in Bosnian pine leaf oleoresins, while Macedonian pine oleoresin contained high amounts of ?-pinene. Furthermore, there were three chemotypes present in Bosnian, and only one in Macedonian pine. Oleoresins of Bosnian pine did not show correlation with climate, however, its composition changed in response to geological substrate type. Macedonian pine oleoresin showed a high correlation with the climate but changed only a little in response to geological substrate type. The oleoresin profiles showed strong species-dependent composition and variability. However, since each species expressed different responses to tested environmental conditions, it is important to take into consideration these variables when analyzing natural populations of the species.

scholarly journals Fern inventorization in Cunca Rami Waterfall Zone of West Manggarai, East Nusa Tenggara

2021 ◽  
Vol 7 (1) ◽  
pp. 218-234
Author(s):  
Muh Sri Yusal ◽  
Gervinus Toni
Keyword(s):  
Local Government ◽  
Environmental Conditions ◽  
Random Sampling ◽  
Pteris Vittata ◽  
Natural Beauty ◽  
Family Types ◽  
Fern Species ◽  
High Level ◽  
Pityrogramma Calomelanos ◽  
Pteris Vittata L

The tourist area of Cunca Rami Waterfall has natural beauty and environmental conditions allow ferns (pteridophyta) to grow and develop diversity high level. This study aims to inventory the types ferns potential in the Cunca Rami West Manggarai waterfall zone East Nusa Tenggara Province, so that is expected to become important information material for the community and local government in developing natural potential-based tourism owned by West Manggarai Regency. Inventory of ferns was carried out through an exploratory method with random sampling which were subsequently identified by reference to the flora book Steenis, et al (2008). The results showed that there were 15 fern types, namely Adiantum diapahnum L.; Drynaria sparsisora (Desv.) More; Pityrogramma calomelanos Link.; Plagigyra sp.; Asplenium belangeri Bory; Asplenium caudatum forst.; Davalia sp.; Diplazium esculentum Swarz.; Dryopteris ferox; Dryopteris pteroides; Lindsaea decomposita Willd; Nephrolepis exaltata schott.; Nephrolepis sp.; Pteris biaurita L.; Pteris vittata L. Then classified into 8 family types, namely Polypodiaceae, Aspleniaceae, Davalliaceae, Athyriaceae, Dryopteridaceae, Lindsacaceae, Neprolepidaceae, and Pteridaceae. Fern species in the Cunca Rami Waterfall area has great potential, but the surrounding community has not utilized use potential full.

Dietary analysis reveals the vulnerability of the endangered Maugean skate (Zearaja maugeana) to benthic changes in Macquarie Harbour

2019 ◽  
Vol 70 (5) ◽  
pp. 745 ◽  
Author(s):  
Kay Weltz ◽  
Jeremy M. Lyle ◽  
Justin D. Bell ◽  
Jayson M. Semmens
Keyword(s):  
Environmental Conditions ◽  
Environmental Changes ◽  
Trophic Position ◽  
Credible Interval ◽  
Prey Type ◽  
Stomach Content Analysis ◽  
Small Population ◽  
Fish Farms ◽  
Dietary Analysis ◽  
Isotopic Signatures

Species occupying high trophic positions with a small population size, limited diet and restricted range are vulnerable to extinction. The endangered Maugean skate (Zearaja maugeana) in Macquarie Harbour is potentially threatened by changing benthic environmental conditions (declining dissolved oxygen concentrations and decreased macrofaunal diversity). To inform investigations on potential indirect impacts of benthic environmental changes on the Maugean skate and its prey, non-lethal techniques were used to identify dietary composition and trophic position of the species. The Maugean skate occupies a high trophic position (3.70) in the food web, with both stable-isotope (median 86% contribution to isotopic signatures, credible interval (CI)=44–100%) and stomach-content analysis showing crustaceans, particularly brachyuran crabs (58.5% index of relative importance), as the dominant prey type. Aquaculture feed from salmonid fish farms operating in the harbour was not found to be important in skate diet. This study showed that the Maugean skate consumes a small number of benthic prey species, highlighting its vulnerability to changing environmental conditions in the harbour.

Short-term stress for long-lasting otolith morphology — brief embryological stress disturbance can reorient otolith ontogenetic trajectory

2018 ◽  
Vol 75 (10) ◽  
pp. 1713-1722 ◽  
Author(s):  
Matthias Vignon
Keyword(s):  
Environmental Conditions ◽  
Salmo Trutta ◽  
Short Term ◽  
Otolith Shape ◽  
Fisheries Resources ◽  
Otolith Morphology ◽  
Ontogenetic Trajectory ◽  
Brown Trout Salmo Trutta ◽  
Long Time

Long-term plasticity of otolith shape has become a unifying principle to use morphological differences as indicator of environmental conditions. Contrary to the longstanding paradigmatic view that otolith shape can only reflect residency in particular environmental conditions over long time periods, data emphasize that otolith ontogenetic trajectory may be reoriented in case of short-term episodes of environmental disturbance during early lifetime. Using geometric morphometrics, discrimination was posible in absence of growth-related differences between control and brown trout (Salmo trutta Linnaeus, 1758) that have experienced brief thermal stress prior to their emergence but have grown in similar conditions (i.e., cohabiting within the same aquarium) during 6 months. Data emphasize that brief stress during key developmental periods can durably influence ontogenetic trajectories, subsequent otolith development, and can consequently change otolith morphology in juveniles. Therefore, differences in shape between groups of fish may not be exclusively indicative of long-time residency in contrasted and (or) separated habitats as it is generally assumed. Moving beyond long-term assumptions is fundamental if otolith shape is to be used as an effective tool for management of fisheries resources in the future.

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