Mechanisms structuring arboreal ant communities along ecological gradients in New Guinea rainforests
PLOWMAN, Nichola Sarah
2018 - English The thesis explores the community ecology and diversity of tropical ants, with a strong focus on the arboreal ants of Papua New Guinea rainforests. The aim was to investigate the drivers of community structure in these diverse communities, and how these change along the ecological gradients of elevation and forest succession. Using unique datasets from censuses of whole forest plots at low, mid and high elevation forests, the effects of vegetation structure and nest microhabitat use on ant community structure and diversity are compared across elevations. Furthermore, a community study of an understorey ant-plant mutualism was undertaken to explore elevational changes in interaction networks and the costs and benefits of mutualistic interaction. For lowland primary and secondary forest, taxonomic, functional and phylogenetic diversity of arboreal ant communities were quantified. In addition, aspects of the methodology of community functional diversity studies are examined, and suggested improvements to data handling in cases where full datasets are not available are discussed. The thesis explores the community ecology and diversity of tropical ants, with a strong focus on the arboreal ants of Papua New Guinea rainforests. The aim was to investigate the drivers of community structure in these diverse communities, and how these change along the ecological gradients of elevation and forest succession. Using unique datasets from censuses of whole forest plots at low, mid and high elevation forests, the effects of vegetation structure and nest microhabitat use on ant community structure and diversity are compared across elevations. Furthermore, a community study of an understorey ant-plant mutualism was undertaken to explore elevational changes in interaction networks and the costs and benefits of mutualistic interaction. For lowland primary and secondary forest, taxonomic, functional and phylogenetic diversity of arboreal ant communities were quantified. In addition, aspects of the methodology of community functional diversity studies are examined, and suggested improvements to data handling in cases where full datasets are not available are discussed. Keywords: ants; Formicidae; New Guinea; tropical forests; elevation; succession; canopy; understorey; vegetation; ecological drivers; ecological gradients Available in the Digital Repository of University of South Bohemia. Mechanisms structuring arboreal ant communities along ecological gradients in New Guinea rainforests

The thesis explores the community ecology and diversity of tropical ants, with a strong focus on the arboreal ants of Papua New Guinea rainforests. The aim was to investigate the drivers of community ...

PLOWMAN, Nichola Sarah
Jihočeská univerzita v Českých Budějovicích, 2018

Non-metabolic use of solar energy in plants
REJŠKOVÁ, Alžběta
2009 - English Non-metabolic use of solar energy in plants can be seen as plant thermoregulation driven directly by solar irradiance. Adaptations leading to warming up are particularly important in cold habitats. Cooling processes are needed everywhere where there is short-term or long-term excess of solar energy. Plants are of utmost importance for ecosystem and landscape functioning. Vegetation has a potential to regulate the Earth{\crq}s surface temperature and improve conditions for other living organisms. By regulating energy and water fluxes between land surface and the atmosphere vegetation is closely related to the climate system. Nemetabolické využití sluneční energie lze u rostlin považovat za termoregulační proces poháněný přímo sluneční energií. Adaptace umožňující zvýšení teploty jsou obzvlášť důležité v chladných oblastech. Chladící procesy jsou zapotřebí všude, kde bývá krátkodobě či dlouhodobě nadbytek sluneční energie. Rostliny jsou nanejvýš důležité pro fungování ekosystémů a krajiny. Vegetace má schopnost regulovat teplotu zemského povrchu a zlepšovat podmínky pro ostatní živé organizmy. Tím, že ovlivňuje toky energie a vody mezi zemským povrchem a atmosférou, je úzce svázaná s fungováním klimatického systému. Keywords: rostlina; termoregulace; sluneční energie; transpirace; evapotranspirace; vodní cyklus; teplota zemského povrchu; klima Available in the Digital Repository of University of South Bohemia. Non-metabolic use of solar energy in plants

Non-metabolic use of solar energy in plants can be seen as plant thermoregulation driven directly by solar irradiance. Adaptations leading to warming up are particularly important in cold habitats. ...

REJŠKOVÁ, Alžběta
Jihočeská univerzita v Českých Budějovicích, 2009

Sex control of common carp (Cyprinus carpio L.)
HULÁK, Martin
2007 - English Available in the Digital Repository of University of South Bohemia. Sex control of common carp (Cyprinus carpio L.)

HULÁK, Martin
Jihočeská univerzita v Českých Budějovicích, 2007

Buněčné a molekulární charakteristiky hemolymfy u raků
KIFAYATULLAH, NA
2023 - English The cellular and molecular components of the hemolymph are the major arm of the innate immune system in decapod crustaceans. In-depth knowledge of the hemolymph components, including hemocytes and hemolymph proteins, can enhance our understanding of innate immunity in crustaceans. We utilized transmission electron microscopy and quantitative proteomics to study the cellular and molecular aspects of coagulation and phagocytosis in the hemolymph. Chapter 2 reviews the cellular and molecular parameters of the innate immune system and the effects of environmental stressors and their abiotic and biotic stress mechanisms in decapod crustaceans. The innate immune system of decapod crustaceans heavily relies on hemocytes in the circulating hemolymph. Generally, three types of hemocytes are accepted based on their morphology, however, there is still a lack of consensus among researchers regarding the classification of hemocyte types. The key innate immune functions such as coagulation and phagocytosis are still poorly understood and require further investigation especially at a molecular level. Environmental stressors can adversely affect the immune responses of decapod crustaceans, increasing their susceptibility to diseases. However, the abiotic stress mechanism is poorly understood due to the lack of available literature and needs further investigation. In Chapter 3, transmission electron microscopy was used to investigate the ultrastructural behavior of hemocytes during coagulation and phagocytosis in the early stages of leg amputation injury in marbled crayfish Procambarus virginalis. The granular hemocytes were the first to be activated, and the morphology of cytoplasmic granules changed from electron-dense to electron-lucent forms in an expanding manner. The transformed granules containing amorphous electron-lucent materials merged and discharged their contents into the extracellular space for coagulation. We observed that the leftover nucleus from degranulated hemocytes participates in the process of coagulation, which could be confused with hyalinocytes in some previous studies. In addition, leg amputation caused massive muscle degeneration, followed by a significant influx of phagocytic hemocytes that removed a substantial amount of muscle fibers and organelles, such as mitochondria, generated from disintegrating and decaying muscle. Furthermore, we found that phagocytic hemocytes contained varying numbers of granules in their cytoplasm and, for the first time, discovered that these cells incorporate necrotic bodies resulting from degenerated muscles into their organelles, such as cytoplasmic granules and nucleus. The granular hemocytes were found to be the main cells that carry out phagocytic activity in the injury site. This study provides a comprehensive description of all the stages of morphological changes in hemocytes during coagulation and phagocytosis after injury in crayfish for the first time. In Chapter 4, proteomic analysis of non-clotted and clotted samples indicated that quantities of most proteins remained unchanged during the coagulation process, suggesting that necessary proteins for coagulation are pre-synthesized and stored before clot formation. Due to their open circulatory system, decapod crustaceans possess robust clotting mechanisms. Upon injury, pre-synthesized clotting factors are released, resulting in clot formation. Therefore, only a few proteins, such as C-type lectin domain-containing proteins, Laminin A chain, and Tropomyosin, were down-regulated during clotting, suggesting their possible roles in the structural integrity of cells. Their downregulation could facilitate degranulation, a crucial step for clot formation. Celulární a molekulární složky hemolymfy jsou hlavní součástí vrozeného imunitního systému u desetinožců. Hlubší znalosti složek hemolymfy, včetně hemocytů a proteinů hemolymfy, mohou zlepšit naše chápání vrozené imunity u korýšů. Pro studium celulárních a molekulárních aspektů koagulace a fagocytózy jsme využili transmisní elektronovou mikroskopii a kvantitativní proteomiku. Kapitola 2 přehledně shrnuje celulární a molekulární parametry vrozeného imunitního systému a účinky environmentálních stresorů a jejich abiotických a biotických stresových mechanismů u desetinožců. Vrozený imunitní systém desetinožců se silně opírá o hemocyty. Obecně jsou přijímány tři typy hemocytů na základě jejich morfologie, avšak stále existuje nedostatek shody ohledně klasifikace typů hemocytů. Klíčové funkce vrozené imunity, jako jsou koagulace a fagocytóza, jsou stále špatně pochopeny a vyžadují další zkoumání zejména na molekulární úrovni. Environmentální stresory mohou negativně ovlivnit imunitní odpovědi desetinožců, čímž zvyšují jejich náchylnost k nemocem. Avšak abiotický stresový mechanismus je špatně pochopen kvůli nedostatku dostupné literatury a vyžaduje další zkoumání. V kapitole 3 byla transmisní elektronová mikroskopie použita k prozkoumání ultrastrukturního chování hemocytů během koagulace a fagocytózy v raných stadiích zranění amputace nohy u raka mramorovaného Procambarus virginalis. Granulární hemocyty byly aktivovány jako první a morfologie cytoplazmatických granulí se změnila z elektronově hustých na elektronově průsvitné formy v expanzivním způsobu. Transformované granule obsahující amorfní elektronově průsvitné materiály se sloučily a vypustily svůj obsah do extracelulárního prostoru pro koagulaci. Pozorovali jsme, že zbývající jádro z degranulovaných hemocytů se podílí na procesu koagulace, což by mohlo být v některých předchozích studiích zaměněno s hyalinocyty. Kromě toho amputace nohy způsobila masivní degeneraci svalů, následovanou významným přílivem fagocytických hemocytů, které odstranily značné množství svalových vláken a organel, jako jsou mitochondrie, generované z rozpadajících se a rozkládajících se svalů. Dále jsme zjistili, že fagocytické hemocyty obsahují různé počty granulí v cytoplazmě a poprvé jsme objevili, že tyto buňky začleňují nekrotická tělíska vzniklá z degenerovaných svalů do svých organel, jako jsou cytoplazmatické granule a jádro. Granulární hemocyty byly nalezeny jako hlavní buňky provádějící fagocytickou aktivitu na místě zranění. Tato studie poskytuje poprvé komplexní popis všech stadií morfologických změn hemocytů během koagulace a fagocytózy po zranění u raků. V kapitole 4 proteomická analýza sražených a nesražených vzorků ukázala, že množství většiny proteinů zůstalo během koagulačního procesu nezměněno, což naznačuje, že nezbytné proteiny pro koagulaci jsou předem syntetizovány a uloženy před vznikem sraženiny. Díky svému otevřenému oběhovému systému mají desetinožci robustní koagulační mechanismy. Po zranění jsou uvolněny předem syntetizované koagulační faktory, což vede ke vzniku sraženiny. Proto byly pouze některé proteiny, jako jsou proteiny obsahující domény C-typu lektinu, laminin A řetězec a tropomyosin, během srážení sníženy, což naznačuje jejich možné role ve strukturní integritě buněk. Jejich snížení by mohlo usnadnit degranulaci, klíčový krok pro vznik sraženiny. Keywords: Vrozená imunita; Srážení hemolymfy; Fagocytóza; Proteomika krevních sraženin Available in the Digital Repository of University of South Bohemia. Buněčné a molekulární charakteristiky hemolymfy u raků

The cellular and molecular components of the hemolymph are the major arm of the innate immune system in decapod crustaceans. In-depth knowledge of the hemolymph components, including hemocytes and ...

KIFAYATULLAH, NA
Jihočeská univerzita v Českých Budějovicích, 2023

Cell segmentation from wide-field light microscopy images using CNNs
GHAZNAVI, Ali
2023 - English Image object segmentation allows localising the region of interest in the image (ROI) and separating the foreground from the background. Cell detection and segmentation are the primary and critical steps in microscopy image analysis. Analysing microscopy images allows us to extract vital information about the cells, including their morphology, size, and life cycle. On the other hand, living cell segmentation is challenging due to the complexity of these datasets. This research focused on developing Artificial Intelligence/Machine Learning methods of single- and multi-class segmentation of living cells. For this study, the Negroid cervical epithelioid carcinoma HeLa line was chosen as the oldest, immortal, and most widely used model cell line. Several time-lapse image series of living HeLa cells were captured using a high-resolved wide-field transmitted/reflected light microscope (custom-made for the Institute of Complex System, Nové Hrady, Czech Republic) to observe micro-objects and cells. Employing a telecentric objective with a high-resolution camera with a large sensor size allows us to achieve a high level of detail and sharper borders in large microscopy images. The collected time-lapse images were calibrated and denoised in the pre-processing step. The data sets collected under the transmission microscope setup were analyzed using a simple U-Net, Attention U-Net, and Residual Attention U-Net to achieve the best single-class semantic segmentation result. The data sets collected under the reflection microscope setup were analyzed using hybrid U-Net methods, including Vgg19-Unet, Inception-Unet, and ResNet34-Unet, to achieve the most precise multi-class segmentation result. Image object segmentation allows localising the region of interest in the image (ROI) and separating the foreground from the background. Cell detection and segmentation are the primary and critical steps in microscopy image analysis. Analysing microscopy images allows us to extract vital information about the cells, including their morphology, size, and life cycle. On the other hand, living cell segmentation is challenging due to the complexity of these datasets. This research focused on developing Artificial Intelligence/Machine Learning methods of single- and multi-class segmentation of living cells. For this study, the Negroid cervical epithelioid carcinoma HeLa line was chosen as the oldest, immortal, and most widely used model cell line. Several time-lapse image series of living HeLa cells were captured using a high-resolved wide-field transmitted/reflected light microscope (custom-made for the Institute of Complex System, Nové Hrady, Czech Republic) to observe micro-objects and cells. Employing a telecentric objective with a high-resolution camera with a large sensor size allows us to achieve a high level of detail and sharper borders in large microscopy images. The collected time-lapse images were calibrated and denoised in the pre-processing step. The data sets collected under the transmission microscope setup were analyzed using a simple U-Net, Attention U-Net, and Residual Attention U-Net to achieve the best single-class semantic segmentation result. The data sets collected under the reflection microscope setup were analyzed using hybrid U-Net methods, including Vgg19-Unet, Inception-Unet, and ResNet34-Unet, to achieve the most precise multi-class segmentation result. Keywords: Categorical segmentation; Neural network; Cell detection; Microscopy image segmentation; U-Net; Tissue segmentation; Semantic segmentation; Bright-Field Microscopy cell segmentation; Cell analysis Available in the Digital Repository of University of South Bohemia. Cell segmentation from wide-field light microscopy images using CNNs

Image object segmentation allows localising the region of interest in the image (ROI) and separating the foreground from the background. Cell detection and segmentation are the primary and critical ...

GHAZNAVI, Ali
Jihočeská univerzita v Českých Budějovicích, 2023

Psychoaktivní sloučeniny ve vodním prostředí a jejich účinky na ryby
SANCHO SANTOS, Maria Eugenia
2021 - English Psychoactive substances are emerging compounds that have received an increasing interest in ecotoxicology as a result of their ubiquitous presence in the environment, and the possible effects over non-targeted fauna. They have been detected in continental waters at concentrations ranging from nanograms to micrograms per litre, mainly as a consequence of the ineffective removal in the sewage treatment plants. Within this group of substances, methamphetamine and tramadol were selected in this dissertation due to the lack of research about their potential effects despite of the high amounts reported in water. Methamphetamine, mainly consumed as an illicit drug, is an addictive psychostimulant with special relevance in Central Europe. Environmental relevant and higher concentrations of methamphetamine in water leaded to histopathological alterations in heart and liver in brown trout (Salmo trutta m. fario). The major changes in heart were microvascular injuries, infiltration and fibrosis; and cytoplasmatic vacuolation of hepatocytes in liver. In addition, apoptotic changes were observed in liver. The findings were very similar to those reported in human and experimental animals. The parent compound and the main metabolite, amphetamine, were detected in trout tissues following the order kidney > liver > brain > muscle > plasma. The concentrations of the metabolite were evidently higher comparing to the parent compound; therefore, the histological findings could be suspected to partially derivate from amphetamine. Behaviour - i.e. activity and place preference - and metabolome changes for the period of withdrawal were observed in trouts, linked to remnants of the parent compound and the metabolite in brain. Tramadol is an extensively used analgesic which singular mode of action provides added antidepressant and anxiolytic effects. Realistic concentration of tramadol in water was found to impair essential behavioural traits in the chub (Squalius cephalus) - a native fish species in Central Europe. The degree of the outcomes was correlated with the individual amounts of tramadol in brain. Exposed fish exhibited anxiolytic-like effects, illustrated by lesser bold and social individuals comparing to controls. In the boldness test, exposed fish were less frequently out of the shelter and moved a shorter distance, therefore, they explored the new environment less than control fish. The novel object recognition experiment indicated that, although they distinguished the new item, their activity was reduced, and they explored the new object less. The increased interindividual distance indicated that the shoal cohesion was disturbed. The behavioural traits were associated to the treatment, suggesting the influence of the pollutant over fish personality. Bioconcentration factors for tramadol and methamphetamine were low in all cases, thus, the probability of bioconcentration for these substances is very low. However, these compounds are continuously released into water, leading to their pseudo-persistence and the consequent presence in tissues. The occurrence in fish, and the parallelism in the target signalization result in similar actions in these organisms comparing to human and experimental models. Here we evidenced that the water pollution with the tested neuroactive substances in the aquatic compartment could lead to unexpected effects over fauna, and subsequent changes in the whole aquatic ecosystem. Psychoaktivní látky patří do skupiny nových kontaminantů životního prostředí a díky jejich všudypřítomnosti a možným účinkům jsou stále častějším předmětem zájmu ekotoxikologických studií. Tyto látky byly detekovány ve vnitrozemských vodách v koncentracích od nanogramů po mikrogramy na litr. Řada z nich není efektivně odstraňována v procesech čištění odpadních vod. Pro experimenty realizované v rámci této disertační práce byly z široké skupiny psychoaktivních látekvybrány metamfetamin a tramadol, a to zejména z důvodu minimálního množství dosud realizovaných ekotoxikologických studií týkajících se působení těchto látek na organismy v životním prostředí a také z důvodu poměrně významných koncentrací těchto látek nalézaných v povrchových vodách. Metamfetamin, užívaný hlavně jako nelegální droga, je návykovým psychostimulantem, který je zejména ve střední Evropě nejčastěji užívanou tzv. "tvrdou" drogou. V rámci práce testované environmentálně relevantní a vyšší koncentrace metamfetaminu ve vodě vedly u pstruha obecného (Salmo trutta m. fario) k histopatologickým změnám v srdci a v játrech. Hlavní změnami pozorovanými v srdci byly mikrovaskulární poranění, infiltrace a fibróza, v játrech pak cytoplazmatická vakuolizace hepatocytů. Kromě toho byly v játrech pozorovány apoptotické změny. Nálezy byly velmi podobné nálezům popisovaným u lidí a laboratorních zvířat. Původní sloučenina a její hlavní metabolit amfetamin byly detekovány ve tkáních pstruhů v pořadí ledviny> játra> mozek> sval> plazma. Koncentrace amfetaminu byly evidentně vyšší ve srovnání s metamfetaminem. Proto lze předpokládat, že histologické nálezy částečně vznikají také působením amfetaminu. U pstruhů vystavených působení metamfetaminu byly v poexpoziční době pozorovány rozdíly v chování mezi exponovanou a kontrolní skupinou. Jednalo se o preference aktivity a místa výskytu a o změny metabolomu mozku, které byly dávány do souvislosti se zbytkovým obsahem metabolitu testované látky v mozku exponovaných jedinců. Tramadol je hojně užívané analgetikum, jehož singulární způsob účinku poskytuje přidané antidepresivní a anxiolytické účinky. Bylo zjištěno, že reálně se vyskytující koncentrace tramadolu ve vodě mění základní způsoby chování jelce tlouště (Squalius cephalus), který je ve střední Evropě původním rybím druhem. Úroveň změn chování korelovala u testovaných jedinců s koncentrací tramadolu v jejich mozku. U exponovaných ryb byly pozorovány anxiolytické účinky, např. menší odvaha a odlišné sociální chování ve srovnání s kontrolními jedinci. V testu smělosti exponované ryby setrvávaly déle v úkrytech a pohybovaly se na kratší vzdálenost, proto prozkoumávaly nové prostředí méně než kontrolní ryby. Experiment zaměřený na schopnost rozpoznávání nových objektů naznačil, že ačkoliv exponovaní jedinci odlišili novou položku, jejich aktivita byla snížena a nový objekt prozkoumávali méně. Zvýšená vzdálenost mezi jedinci naznačovala, že je narušena soudržnost hejna. S expozicí byly spojeny i změny chování, což naznačuje vliv znečišťující látky na osobnost ryb. Biokoncentrační faktory pro tramadol a metamfetamin byly ve všech případech nízké, takže pravděpodobnost biokoncentrace je v případě těchto látek velmi nízká. Tyto sloučeniny se však kontinuálně dostávají do vody, což vede k jejich pseudo-perzistenci a následné přítomnosti ve tkáních. Výskyt u ryb a paralelismus v cílové signalizaci vedou k podobným reakcím v těchto organismech jako jsou pozorovány u lidských a dalších živočišných modelů. V našich experimentech jsme prokázali, že znečištění vody testovanými neuroaktivními látkami může vést k neočekávaným účinkům na faunu a následným změnám v celém vodním ekosystému. Keywords: chování; biokoncentrace; droga; ryba; farmaceutika; znečištění Available in the Digital Repository of University of South Bohemia. Psychoaktivní sloučeniny ve vodním prostředí a jejich účinky na ryby

Psychoactive substances are emerging compounds that have received an increasing interest in ecotoxicology as a result of their ubiquitous presence in the environment, and the possible effects over ...

SANCHO SANTOS, Maria Eugenia
Jihočeská univerzita v Českých Budějovicích, 2021

Vliv antropogenních vstupů dusíku na strukturu a funkci ektomykorhizních společenstev smrkových lesů
CHOMA, Michal
2020 - English The effect of anthropogenic nitrogen (N) inputs on the structure of ectomycorrhizal fungal communities in Norway spruce forests was investigated. With the use of soil DNA amplicon sequencing, ectomycorrhizal communities were described in spruce forests exposed historically to different anthropogenic N deposition and experimental manipulative N treatments. This information was put into context with soil biochemical properties and rates of soil processes involved in C and N cycling in order to reveal possible consequences of ectomycorrhizal community restructuring for soil and ecosystem functioning. Práce se zabývá vlivem antropogenních vstupů dusíku (N) na strukturu společenstev ektomykorhizních hub ve smrkových lesích. Pomocí sekvenace půdní DNA byla popsána ektomykorhizní společenstva v lesích s odlišnou historickou depozicí N a různými experimentálními přídavky N. Získaná informace byla dána do kontextu s měřenými půdními biochemickým parametry a procesy, aby bylo možno odvodit možné důsledky změn v ektomykorhizních společenstev na fungování ekosystému. Keywords: Ektomykorhizní houby; smrkové lesy; půda; atmosférická depozice dusíku; hnojení dusíkem Available in the Digital Repository of University of South Bohemia. Vliv antropogenních vstupů dusíku na strukturu a funkci ektomykorhizních společenstev smrkových lesů

The effect of anthropogenic nitrogen (N) inputs on the structure of ectomycorrhizal fungal communities in Norway spruce forests was investigated. With the use of soil DNA amplicon sequencing, ...

CHOMA, Michal
Jihočeská univerzita v Českých Budějovicích, 2020

Molecular Factors of Cell Antiviral Immunity
SELINGER, Martin
2019 - English The proposed thesis focuses on the description of flavivirus-host interactions in case of tick-borne encephalitis virus (TBEV) and Zika virus (ZIKV). In more detail, the TBEV-induced host responses in human cells of neural origin and interferon-mediated protection were described together with the identification of a new phenomenon of TBEV-induced host transcriptional and translational shut-off. In addition, virus-derived molecules with hypothetical immunomodulatory characteristics, TuORF and ZIKV sfRNA, were analysed for their presence and possible function during the infection. The proposed thesis focuses on the description of flavivirus-host interactions in case of tick-borne encephalitis virus (TBEV) and Zika virus (ZIKV). In more detail, the TBEV-induced host responses in human cells of neural origin and interferon-mediated protection were described together with the identification of a new phenomenon of TBEV-induced host transcriptional and translational shut-off. In addition, virus-derived molecules with hypothetical immunomodulatory characteristics, TuORF and ZIKV sfRNA, were analysed for their presence and possible function during the infection. Keywords: flaviviruses; tick-borne encephalitis virus; Zika virus; host response; neural cells; interferon Available in the Digital Repository of University of South Bohemia. Molecular Factors of Cell Antiviral Immunity

The proposed thesis focuses on the description of flavivirus-host interactions in case of tick-borne encephalitis virus (TBEV) and Zika virus (ZIKV). In more detail, the TBEV-induced host responses ...

SELINGER, Martin
Jihočeská univerzita v Českých Budějovicích, 2019

Systematika zelených kokálních řas tříd Chlorophyceae a Trebouxiophyceae
ŠTENCLOVÁ, Lenka
2020 - English Aim of the review part is to summarize a current situation in the systematics of the green coccal algae, which were traditionally assembled in only one order: Chlorococcales. Their distribution into the lower taxonomical unites (suborders, families, subfamilies, genera) was based on the classic morphological criteria as shape of the cell and characteristics of the colony. Introduction of molecular methods caused radical changes in our insight to the system of green (not only coccal) algae and green coccal algae were redistributed in two of newly described classes: Chlorophyceae a Trebouxiophyceae. Representatives of individual morphologically delimited families, subfamilies and even genera and species were commonly split in several lineages, often in both of mentioned classes. For the practical part, was chosen two problematical groups of green coccal algae: family Oocystaceae and family Scenedesmaceae - specifically its subfamily Crucigenioideae, which were revised using polyphasic approach. Based on the molecular phylogeny, relevance of some old traditional morphological traits was reevaluated and replaced by newly defined significant characteristics. Aim of the review part is to summarize a current situation in the systematics of the green coccal algae, which were traditionally assembled in only one order: Chlorococcales. Their distribution into the lower taxonomical unites (suborders, families, subfamilies, genera) was based on the classic morphological criteria as shape of the cell and characteristics of the colony. Introduction of molecular methods caused radical changes in our insight to the system of green (not only coccal) algae and green coccal algae were redistributed in two of newly described classes: Chlorophyceae a Trebouxiophyceae. Representatives of individual morphologically delimited families, subfamilies and even genera and species were commonly split in several lineages, often in both of mentioned classes. For the practical part, was chosen two problematical groups of green coccal algae: family Oocystaceae and family Scenedesmaceae - specifically its subfamily Crucigenioideae, which were revised using polyphasic approach. Based on the molecular phylogeny, relevance of some old traditional morphological traits was reevaluated and replaced by newly defined significant characteristics. Keywords: green algae; systematics; phylogeny; Chlorophyceae; Trebouxiophyceae; Oocystaceae; Crucigenioideae Available in the Digital Repository of University of South Bohemia. Systematika zelených kokálních řas tříd Chlorophyceae a Trebouxiophyceae

Aim of the review part is to summarize a current situation in the systematics of the green coccal algae, which were traditionally assembled in only one order: Chlorococcales. Their distribution into ...

ŠTENCLOVÁ, Lenka
Jihočeská univerzita v Českých Budějovicích, 2020

The effect of tropical land use change on soil-dwelling ants and termites, their interaction and on ecosystem processes they affect
TŮMA, Jiří
2020 - English In this thesis I explore the role of tropical soil-dwelling ants and termites in driving ecosystem processes, their mutual interaction and their responses to tropical land use change. To do this I use a combination of methods, including a full review of the ant-termite interaction literature, field sampling for ants and termites, DNA barcoding-based inference of ant predation on termites, and creation and implementation of a new protocol for measuring terrestrial bioturbation. I found that the literature mainly documents anecdotal observations of interactions between ants and termites, the vast majority of which are predatory. Many of these appear to be opportunistic predation of termites by non-specific ants, although some ant species have developed sophisticated methods that enable them to specialise on termite predation. My field sampling demonstrated that soil ants and termites are susceptible to habitat degradation, with logging having minimal impacts, but conversion to oil palm affecting both groups to a greater extent. The predation rate of ants on termites differs between ant taxa, but seems to be stable across habitats. Finally, termites are important for soil bioturbation in all habitat types, but overall, this ecosystem function relies only on few species in oil palm plantations, raising concerns about susceptibility of this function to future extinctions. My work emphasizes the importance of maintaining the diversity of these two trophically linked groups for the ecosystem functions they provide. In this thesis I explore the role of tropical soil-dwelling ants and termites in driving ecosystem processes, their mutual interaction and their responses to tropical land use change. To do this I use a combination of methods, including a full review of the ant-termite interaction literature, field sampling for ants and termites, DNA barcoding-based inference of ant predation on termites, and creation and implementation of a new protocol for measuring terrestrial bioturbation. I found that the literature mainly documents anecdotal observations of interactions between ants and termites, the vast majority of which are predatory. Many of these appear to be opportunistic predation of termites by non-specific ants, although some ant species have developed sophisticated methods that enable them to specialise on termite predation. My field sampling demonstrated that soil ants and termites are susceptible to habitat degradation, with logging having minimal impacts, but conversion to oil palm affecting both groups to a greater extent. The predation rate of ants on termites differs between ant taxa, but seems to be stable across habitats. Finally, termites are important for soil bioturbation in all habitat types, but overall, this ecosystem function relies only on few species in oil palm plantations, raising concerns about susceptibility of this function to future extinctions. My work emphasizes the importance of maintaining the diversity of these two trophically linked groups for the ecosystem functions they provide. Keywords: land use; ants; termites; interaction; tropical habitats; soil; oil palm; bioturbation Available in the Digital Repository of University of South Bohemia. The effect of tropical land use change on soil-dwelling ants and termites, their interaction and on ecosystem processes they affect

In this thesis I explore the role of tropical soil-dwelling ants and termites in driving ecosystem processes, their mutual interaction and their responses to tropical land use change. To do this I ...

TŮMA, Jiří
Jihočeská univerzita v Českých Budějovicích, 2020