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2652. Assessing institutional determinants of MP behaviour: survey data from the Baltic States
- Creator:
- Pettai, Vello
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2653. Assessing shade stress in leaves of turf-type tall fescue (Festuca arundinacea Schreb.)
- Creator:
- He, Q. and Li, D.
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- lawn, low light, photosynthesis, senescence, and vegetation index
- Language:
- Multiple languages
- Description:
- Shade treatment was applied to tall fescue with 30% full light. The results showed that shade increased chlorophyll (Chl) content per unit leaf mass, decreased the Chl a/b ratio in the mature leaves, and decreased effective quantum yield based on Chl fluorescence compared to the full light treatment. Shade stress did not cause increased contents of malondiadehyde at the early stages of leaf development. However, normalized vegetation indices were able to detect shade stress. Chloroplasts in the shaded leaves are arranged tightly against the periclinal cell wall and are in a spindle shape. There were no differences in the number of grana per chloroplast or grana size (thylakoids per granum) between shade and full light treatment. In conclusion, tall fescue leaves showed unique ultrastructure changes. Turfgrass managers could use vegetation indices developed from the leaf light reflection spectrum as an effective tool to assess shade stress levels and make management decisions.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2654. Assessing temporal variation and autocorrelation in fish habitat use
- Creator:
- Vilizzi, Lorenzo, Copp, Gordon H., and Roussel, Jean-Marc
- Type:
- article and TEXT
- Subject:
- PHABSIM, fish behaviour, individual-based models (IBMs), PCA, semi-variogram, log-linear analysis, and pseudoreplication
- Language:
- English
- Description:
- We assessed the xtent of temporal variation and autocorrelation in fish habitat use based on an experimental study of individual 0+ juvenile barbel, Barbus barbus, in an artificial flume. Five treated and five control fish were individually subjected to an increase in discharege (intervention) hlfway through each experiment and kept at baseline discharge throughout, respectively. Preference surves for velocity were generated for each of 60 trials per experiment and for each combination of treated/control (fish) x before/after-intervention. There were large between- and within-individual differences in velocity preference, both in treated and in control fish. Most barbel explored the entire range of velocities, whereas some individuals used a more limited range. Temporal variation in behavioural responses was assessed by a PCA-based methodology. Autocorrelation (i.e. correlation between sequential trials) was diagnosed in most response profiles, supporting recent fidings that individuals may have a "memory" of their past velocity usage. The relevance of the results for numerical habitat models of fish habitat assessment is discussed, as well as the importance of incorporating temporal variability into fish habitat use models (e.g. PHABSIM), not only as ontogenetic intervals but also as longitudinal data of individual behaviours. A warning is also re-issued about the erroneous belief of "pseudoreplication" simly arising from repeated measurements in time.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
2655. Assessing the after-effects of changes in the river flow regime due to different hydrotechnical constructions upon floodplain ecosystems
- Creator:
- Kouzmina, J.V., Treshkin, S.Y., Avetjan, S.A., and Henrichfreise, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- regulated river flow, floodplain ecosystem, environment conservation, regulovaný prietok riek, ekosystémy záplavových území, and ochrana životného prostredia
- Language:
- Slovak
- Description:
- The complex environmental research (hydrology, vegetation, soils and ground water) has been carried out in nature reserves, located on the Danube banks within the zone of broad-leaved forests in Germany. Under comparison were terrestrial ecosystems along the regulated and natural rivers. It was established that the weirs, dams with low head of water and small artificial reservoirs affects upon the vegetation and soils of floodplains to be manifested some decades later. A comprehensive analysis of trends in mean annual water level, water flow and the precipitation for the long period revealed the significant influence of natural long-term variability of the water content on the vegetation dynamics in floodplains. The methods, suggested by the authors made possible to assess the after-effects upon floodplain ecosystems due to changes in the river flow regime caused by different hydrotechnical constructions. and V prírodných rezerváciách v blízkosti Dunaja (v Nemecku) v oblasti pokrytej listnatými lesmi bol vykonaný komplexný environmentálny výskum (hydrológia, vegetácia, pôdy a podzemné vody). Porovnávali sa ekosystémy pozdĺž regulovaných a prirodzených tokov. Zistilo sa, že hate a priehrady s relatívne malým vzdutím, ako aj malé vodné nádrže ovplyvňovali vegetáciu a pôdy v záplavových územiach tak, že sa to prejavilo už o niekoľko desaťročí neskôr. Vyčerpávajúca analýza trendov priemernej ročnej výšky hladín, prietokov a zrážok počas dlhého obdobia pomohla objasniť významný vplyv prirodzenej dlhodobej variability obsahu vody na dynamiku vegetácie v zátopových územiach. Metóda navrhnutá autormi umožňuje určiť následné vplyvy zmien vodného režimu tokov spôsobených hydrotechnickými stavbami na ekosystém v záplavovom území.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2656. Assessing the efficiency of using passive hair traps as a method for non-invasive sampling from European beavers (Castor fiber L.)
- Creator:
- Sobkowiak, Marta, Kochan, Joanna I., and Kruszyński, Wojciech
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- Castor sp., genetic monitoring, hair collecting, and DNA
- Language:
- English
- Description:
- Using passive hair traps to obtain genetic material from wild mammals is an effective form of testing the abundance of animal populations. Based on genetic analysis of collected hair, it is possible to estimate the number and sex of individuals present in a given area. The aim of this study was to confirm the success of the method of collecting hair from beavers in a non-invasive way, as well as to determine the effectiveness of using passive hair traps as sampling tools that can be applied in different regions. The study was carried out in the area of Stobrawa Landscape Park (southwestern Poland) between December 2017 and May 2018. For 17 control days, 12 samples were obtained, which gave the result of 0.7 samples per control day. This study shows that the proposed method, due to its simplicity and efficiency, could be a cost-effective way of collecting hair from free-ranging beavers without the need for capturing individuals.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2657. Assessing the efficiency of UV LEDs as light sources for sampling the diversity of macro-moths (Lepidoptera)
- Creator:
- Infusino, Marco, Brehm, Gunnar, Di Marco, Carlo, and Scalercio, Stefano
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, lesní ekosystémy, motýli, butterflies, forest ecosystems, Středozemní moře (oblast), Itálie, Mediterranean area, Italy, Lepidoptera, light trapping, UV LEDs, diversity, 2, and 59
- Language:
- English
- Description:
- Light trapping is the most widely used tool for determining the diversity of nocturnal Lepidoptera, but UV LEDs have yet to be used as light sources for the large-scale monitoring of Lepidoptera. We assessed the efficiency of this novel light source for sampling moths using a Heath type moth equipped with a strip of 150 high brightness UV LEDs (emission peak 398 nm, ~ 15 W) powered by a 12 V battery. We compared the number of individuals, the number of species and the Geometridae / Noctuidae ratio recorded for the samples collected using UV LED traps with those collected in two monitoring programs carried out in the same geographic region using two different light sources: a 200 W incandescent lamp (Rothamsted trap) and a 160 W mercury vapour lamp (manual catch). The total catch consisted of 61,120 individuals belonging to 699 species. The species richness rarefaction curves revealed that the Rothamsted trap collected fewer species and individuals than UV LED traps. Furthermore, the median numbers of species and individuals caught by UV LED traps fell within the range of those caught by mercury vapour lamp traps. In addition, the community composition recorded using incandescent lamps and UV LEDs was similar. The data obtained using UV LED traps, in absolute terms and in comparison with the other light sources and different sampling methods, clearly reveal that this light source is suitable for sampling macro-moth communities. For field work UV LEDs have many advantages, as they are resistant to mechanical damage, easily protected from heavy rain and energy efficient., Marco Infusino, Gunnar Brehm, Carlo Di Marco, Stefano Scalercio., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2658. Assessing the relationship between photosynthetic C accumulation and symbiotic N nutrition in leaves of field-grown nodulated cowpea (Vigna unguiculata L. Walp.) genotypes
- Creator:
- Belane, A. K. and Dakora, F. D.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, N2 fixation, photosynthetic fixed-N use efficiency, transpiration efficiency, δ15N, 2, and 581
- Language:
- Multiple languages
- Description:
- a1_This study evaluated the relationship between photosynthetic carbon accumulation and symbiotic nitrogen nutrition in young fully expanded leaves of 30 nodulated cowpea genotypes grown in the field at Manga, Ghana, in 2005 and 2006. Estimates of fixed-N in photosynthetic leaves revealed greater symbiotic N in genotypes with higher photosynthetic rates and increased leaf transpiration rate/efficiency. There was also greater C accumulation in genotypes with higher symbiotic N and/or total N. Additionally, genotypes with high contents of C per unit of leaf total N exhibited greater C per unit of leaf N-fixed. The C/N and C/Rubisco-N ratios were generally similar in their magnitude when compared to the C/N-fixed ratio due possibly to the fact that Rubisco accounts for a high proportion of photosynthetic leaf N, irrespective of whether the enzyme was formed from soil N or symbiotic N. Cowpea genotypes that relied heavily on soil N for their N nutrition exhibited much higher C/N-fixed ratios, while conversely those that depended more on symbiosis for meeting their N demands showed markedly lower C/N-fixed values. For example, genotypes Omondaw, Bensogla, IT93K-2045-29, and Sanzie, which respectively derived 83.9, 83.1, 82.9, and 76.3% N from fixation, recorded lower C/N-fixed ratios of 10.7, 12.2, 12.1, and 13.0 mg mg-1 in that order in 2005. In contrast, genotypes Botswana White, IT94D-437-1, TVu1509, and Apagbaala, which obtained 14.8, 15.0, 26.4, and 26.0% of their N nutrition from fixation, showed high C/N-fixed values of 84.0, 69.0, 35.2, and 40.6 mg.mg-1, respectively, in 2005., a2_This clearly indicates that genotypes that obtained less N from symbiosis and more N from soil revealed very high C/N-fixed values, an argument that was reinforced by the negative correlations obtained between the three C/N ratios (i.e. C/N, C/Rubisco-N, and C/N-fixed) and leaf N concentration, percentage nitrogen derived from fixation, total N content, amount of N-fixed, and Rubisco N. These data suggest a direct link between photosynthetic C accumulation and symbiotic N assimilation in leaves of nodulated cowpea, and where genotypes derived a large proportion of their N from fixation, photosynthetic C yield substantially increased., A. K. Belane, F. D. Dakora., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2659. Assessing the retention capacity of a floodplain using a 2D numerical model
- Creator:
- Valentová, Jana, Valenta, Petr, and Weyskrabová, Lenka
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- two-dimensional numerical modeling, floodplain retention capacity, transformation of a flood wave, dvourozměrné numerické modelování, retenční kapacita nivy, and transformace povodňové vlny
- Language:
- Slovak
- Description:
- This paper presents a method for assessing the retention capacity of a floodplain in the course of flooding and for estimating the significance of its water storage for transforming a flood wave. The method is based on two-dimensional numerical modeling of the flood flow in a river channel and in the adjacent floodplains, and is suitable for cases when the morphology of the flooding area is variable and complex, e.g. broad inundation areas with meandering channels. The approach adopted here enables us to quantify the retention capacity for inundation areas of various characters and with various land uses, and provides a tool for estimating the efficiency of possible measures for increasing the water storage capacity of a floodplain. The retention capacity is estimated using an evaluation of a series of detailed flood flow modeling results; the flood wave transformation effect is predicted with the aim of creating a non-linear reservoir model. A parametric study of the floodplain retention capacity for the upper branch of the Lužnice River is presented here, and the results for the current state and for various hypothetical scenarios of changes in geometry and land use are evaluated and compared. and V příspěvku je prezentována metodika pro stanovení retenční kapacity inundačního území při povodňových průtocích a jeho význam pro transformaci povodňové vlny. Metoda využívá dvourozměrný numerický model proudění vody korytem a přilehlým inundačním územím a je vhodná pro případy, kdy charakter nivy je proměnlivý a velmi komplikovaný, např. široká inundační území s meandrujícími toky. Navržený způsob řešení umožňuje kvantifikovat retenční schopnosti niv různého charakteru při různých způsobech využívání a umožňuje případně navrhnout úpravu inundačního území tak, aby transformační účinek při průchodu povodňové vlny byl co největší. Retenční kapacita inundačního území je stanovena na základě výsledků podrobného modelování proudění vody při různých průtokových stavech a transformace povodňové vlny je řešena pomocí iteračního postupu založeného na Bratránkově metodě. V příspěvku je uvedena parametrická studie kvantifikace retenční kapacity nivy na základě vyhodnocení a porovnání transformační schopnosti pro nivu Lužnice v jejím horním úseku pro současný přirozený stav a pro různé teoretické scénáře změněného charakteru a způsobu využívání nivy.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2660. Assessing the role of vertical leaves within the photosynthetic function of Styrax camporum under drought conditions
- Creator:
- Feistler, A. M. and Habermann, G.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, Brazilian savanna, chlorophyll fluorescence, gas exchange, leaf surface, paraheliotropism, Styracaceae, 2, and 58
- Language:
- Multiple languages
- Description:
- Previous evidence has demonstrated that vertical leaves of Styrax camporum, a woody shrub from the Brazilian savanna, have a higher net photosynthetic rate (PN) compared with horizontal leaves, and that it is detected only if gas exchange is measured with light interception by both leaf surfaces. In the present study, leaf temperature (T leaf), gas exchange and chlorophyll (Chl) a fluorescence with light interception on adaxial and also on abaxial surfaces of vertical and horizontal mature fully-expanded leaves subjected to water deficit (WD) were measured. Similar gas-exchange and fluorescence values were found when the leaves were measured with light interception on the respective surfaces of horizontal and vertical leaves. WD reduced N values measured with light interception on leaf surfaces of both leaf types, but the effective quantum yield of PSII (ΦPSII) and the apparent electron transport rate (ETR) were reduced only when the leaves were measured with light interception on the adaxial surface. WD did not decrease the maximum quantum yield of PSII (Fv/Fm) or increase T leaf, even at the peak of WD stress. Vertical leaf orientation in S. camporum is not related to leaf heat avoidance. In addition, the similar P N values and the lack of higher values of ΦPSII and ETR in vertical compared with horizontal leaves measured with light interception by each of the leaf surfaces suggests that the vertical leaf position is not related to photoprotection in this species, even when subjected to drought conditions. The exclusion of this photoprotective role could raise the alternative hypothesis that diverse leaf angles sustain whole plant light interception efficiency increased in this species., A. M. Feistler, G. Habermann., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public