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1.
Vortices determine the dynamics of biodiversity in cyclical interactions with protection spillovers
Attila Szolnoki, Matjaž Perc, 2015, izvirni znanstveni članek

Opis: If rock beats scissors and scissors beat paper, one might assume that rock beats paper too. But this is not the case for intransitive relationships that make up the famous rock-paper-scissors game. However, the sole presence of paper might prevent rock from beating scissors, simply because paper beats rock. This is the blueprint for the rock-paper-scissors game with protection spillovers, which has recently been introduced as a new paradigm for biodiversity in well-mixed microbial populations. Here we study the game in structured populations, demonstrating that protection spillovers give rise to spatial patterns that are impossible to observe in the classical rock-paper-scissors game.Weshow that the spatiotemporal dynamics of the system is determined by the density of stable vortices, which may ultimately transform to frozen states, to propagating waves, or to target waves with reversed propagation direction, depending further on the degree and type of randomness in the interactions among the species. If vortices are rare, the fixation to waves and complex oscillatory solutions is likelier. Moreover, annealed randomness in interactions favors the emergence of target waves, while quenched randomness favors collective synchronization. Our results demonstrate that protection spillovers may fundamentally change the dynamics of cyclic dominance in structured populations, and they outline the possibility of programming pattern formation in microbial populations.
Ključne besede: cyclical interactions, pattern formation, vortices, phase transitions, selforganization, biodiversity
Objavljeno: 03.07.2017; Ogledov: 203; Prenosov: 111
.pdf Celotno besedilo (1,32 MB)
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2.
Biodiversity in models of cyclic dominance is preserved by heterogeneity in site-specific invasion rates
Attila Szolnoki, Matjaž Perc, 2016, izvirni znanstveni članek

Opis: Global, population-wide oscillations in models of cyclic dominance may result in the collapse of biodiversity due to the accidental extinction of one species in the loop. Previous research has shown that such oscillations can emerge if the interaction network has small-world properties, and more generally, because of long-range interactions among individuals or because of mobility. But although these features are all common in nature, global oscillations are rarely observed in actual biological systems. This begets the question what is the missing ingredient that would prevent local oscillations to synchronize across the population to form global oscillations. Here we show that, although heterogeneous species-specific invasion rates fail to have a noticeable impact on species coexistence, randomness in site-specific invasion rates successfully hinders the emergence of global oscillations and thus preserves biodiversity. Our model takes into account that the environment is often not uniform but rather spatially heterogeneous, which may influence the success of microscopic dynamics locally. This prevents the synchronization of locally emerging oscillations, and ultimately results in a phenomenon where one type of randomness is used to mitigate the adverse effects of other types of randomness in the system.
Ključne besede: biodiversity, cyclic dominance, rock-paper-scissors, physics of social systems
Objavljeno: 23.06.2017; Ogledov: 178; Prenosov: 77
.pdf Celotno besedilo (419,58 KB)
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3.
Mitigating the conflict between pitfall-trap sampling and conservation of terrestrial subterranean communities in caves
Peter Kozel, Tanja Pipan, Nina Šajna, Slavko Polak, Tone Novak, 2017, izvirni znanstveni članek

Opis: Subterranean habitats are known for their rich endemic fauna and high vulnerability to disturbance. Many methods and techniques are used to sample the biodiversity of terrestrial invertebrate fauna in caves, among which pitfall trapping remains one of the most frequently used and effective ones. However, this method has turned out to be harmful to subterranean communities if applied inappropriately. Traditionally, pitfall traps have been placed in caves solely on the ground. Here we present an optimized technique of pitfall trapping to achieve a balance between sampling completeness and minimal disturbance of the fauna in the cave. Monthly we placed traps for two days in two parallel sets, a ground trap and an upper one−just below the ceiling−along the cave. In the upper set, about 10% additional species were recorded compared to the ground set. Greater species diversity in the cave was the consequence of both the increased sampling effort and the amplified heterogeneity of sampled microhabitats. In caves sampled by traditional pitfall trapping, overlooked species may be a consequence of methodological biases, leading to lower biodiversity estimates. In our research, incidence-based estimations mostly surpassed abundance-based ones and predicted 95% coverage of the species richness within about two years of sampling. The sampling used contributes at the same time to both the more effective and less invasive inventory of the subterranean fauna. Thus, it may serve as an optional sampling to achieve optimal balance between required data for biodiversity and ecological studies, and nature conservation goals.
Ključne besede: biodiversity estimators, microhabitats, sampling effort, sampling techniques, biological inventories
Objavljeno: 30.10.2017; Ogledov: 259; Prenosov: 99
.pdf Celotno besedilo (2,53 MB)
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4.
Nature protection in Bosnia and Herzegovina
Samir Đug, Nusret Drešković, 2012, izvirni znanstveni članek

Opis: Bosnia and Herzegovina is distinguished by a very unique mosaic of high biodiversity level. However, current development activities and initiatives for construction of new dams, together with activities in the forestry sector throughout the country, emphasizes the need for establishment of new protected areas in all major ecosystem types that should be ecologically viable and effectively managed. A review of the history of protected areas and administration developments in Bosnia and Herzegovina provide useful input for analysis. However, the data on the current state and size of protected areas in the country are obsolate and inaccurate. The results of the analysis have shown that in spite of a very high biodiversity level, Bosnia and Herzegovina managed to designate only 2.6% of its territory as protected areas, which is far below regional and European level. Lack of protected areas system is one of the main direct threats to biodiversity conservation. The primary objective of establishment of protected area network (PAN) in Bosnia and Herzegovina is to ensure conservation of valuable natural areas, which contain representatives of all main ecosystem types that could be found in the country. Only in this way, sustainable conservation of biodiversity could be achieved.
Ključne besede: protected areas, biodiversity management, Bosnia and Herzegovina
Objavljeno: 10.04.2018; Ogledov: 152; Prenosov: 21
.pdf Celotno besedilo (323,43 KB)
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5.
Agronomski in okoljski vidiki prekrivnih posevkov v ekološki pridelavi zelenjadnic
Martina Robačer, 2019, doktorsko delo/naloga

Opis: Cover crops can reduce the use of external inputs such as pesticides and fertilisers and can at the same time suppress weeds as well as improve or maintain soil fertility. Cover crops can also modify the microclimate which affects pest populations and diseases. Determining cover crop species and management practices is based on the needs and goals of production. The effects of introducing living mulch (LM) and management strategies on cash crop yield, product quality and energy use were studied in certain European countries (Slovenia, Italy, Germany and Denmark) in different climatic and soil conditions. In Slovenia, in organic production of cauliflower and leek, the effects of two terms of sowing white clover with additive design were compared with a production with black foil and with the usual agricultural practice by hoeing. In the field experiments the effect of LM on arthropod dynamics and activity density was investigated. The results demonstrated that the LM systems with a substitutive design, can be effectively implemented in vegetable production if the value of the ecological services (positive externalities) delivered by LM can counterbalance the yield loss due to the cash crop density reduction. If an additive design is used, the LM should be sown several weeks after the cash crop planting. Different cash crop genotypes (i.e., open pollinated/local cultivars in comparison with the hybrids) performed similarly. Use of human labor (HL) and fossil fuel (FF) energy slightly increased in LM systems (7%). The farmers’ acceptance of the LM techniques was quite high (75% of the interviewed sample). The LM technique did not affect the infestation of cabbage caterpillar Pieris spp., showing no detrimental effect of this technique on this key pest of cabbage. In Denmark, aphid populations were higher in the sole crop system than in the LM system. In Italy, a level of larval parasitization was detected and in the first year the percentage of parasitization was higher in LM (88%) than in sole crop (63%). Overall, the LM positively affected the activity density of Carabid beetles, also increasing the diversity and evenness of species (Slovenia and Italy) or activity density of some taxa (Slovenia and Denmark). Due to numerous agroecological services of cover crops, growing simultaneously with vegetables as LM, this could be promising technique for organic and others production systems in the future.
Ključne besede: organic vegetable production, cover crops, agroecological service, living mulch, energy consumption, biodiversity, soil arthropod
Objavljeno: 01.02.2019; Ogledov: 251; Prenosov: 50
.pdf Celotno besedilo (1,43 MB)

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