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Ecology of grazing lawns on tallgrass prairieShaffer, Monica January 1900 (has links)
Master of Science / Department of Biology / David C. Hartnett / A key feature of many grass-dominated ecosystems is the formation of grazing lawns, distinct patches characterized by intense grazing by mammalian herbivores and a dense short-statured grass canopy. A central concept of grazing lawns is the positive feedbacks between grazing animals and the grass resource. Intraspecific morphological plant trait changes and differences in plant species composition could both or individually play a role in the differences in characteristics of grazing lawns and neighboring tallgrass swards. I studied grazing lawns in North American tallgrass prairie to: a) test the ‘architectural shift hypothesis’ where continued grazing leads to changes in plant architecture resulting in more efficient foraging for grazers, creating a positive feedback that increases grazing and b) examine soil resource (nutrient and water) availability and grass nutritive quality on and off lawns to test the nutrient- and water-based pathways for grazing lawn maintenance. In a separate study (not reported here), we a) examined plant community structure on and off lawns to determine whether species composition differences account for the distinct grazing lawn characteristics and b) assessed effects of grazing lawn formation on tallgrass prairie plant species diversity.
Several differences in morphological traits between dominant grasses on grazing lawns and tallgrass swards support the architectural shift hypothesis. For Sorghastrum nutans, Dichanthelium oligosanthes, and Pascopyrum smithii, leaf-to-stem ratio was twice as high on grazing lawns compared to surrounding matrix tallgrass vegetation and tiller branching was higher and culm internode lengths were shorter on grazing lawns for these species. However, Andropogon gerardii traits did not differ between grazing lawns and tallgrass vegetation. For all four species, above-ground tiller biomass and number of below-ground buds were both higher on grazing lawns. Overall, these morphological responses resulted in a higher grass canopy density (forage biomass per unit canopy volume) on grazing lawns and this increased grass canopy density in turn results in higher grazer foraging efficiency by increasing the amount of forage intake per bite and per unit time.
D. oligosanthes, P. smithii, and S. nutans plants on grazing lawns had a significantly lower carbon-to-nitrogen ratio and higher nitrogen content than plants in the matrix tallgrass vegetation, while A. gerardii showed no significant difference in nitrogen content or in carbon-to-nitrogen ratio between grazing lawns and surrounding matrix tallgrass vegetation. With regards to the total grass canopy (all grass species combined), nitrogen content was significantly higher on grazing lawns compared to tallgrass vegetation for all three field seasons, 2016, 2017, and 2018. All measured soil nutrients, ammonium, nitrate, phosphorus, and sodium, were significantly higher on grazing lawns compared to soils of surrounding tallgrass swards, while water content showed no significant difference between grazing lawns and surrounding tallgrass vegetation.
The results of this study strongly indicate that developmental and morphological shifts result in increased forage density and increased grazing efficiency on grazing lawns and that the frequent and intense activities of large grazers result in increased plant nitrogen content and lower C:N ratios in grasses on tallgrass prairie grazing lawns. Thus, at least two different mechanisms, plant architectural shifts and the nutrient-based pathway could both contribute to the positive feedbacks that encourage further grazing on lawns and grazing lawn maintenance on tallgrass prairie.
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Fire dynamics and carbon cycling in miombo woodlandsBowers, Samuel Jonathan January 2017 (has links)
Savannah ecosystems play a prominent role in the global carbon (C) cycle, yet fluxes are poorly quantified, and the key processes regulating vegetation dynamics are uncertain. Insight is particularly deficient in southern Africa’s miombo woodlands, a woody savannah that is home to over 100 million people. This biome is heavily disturbed, with widespread deforestation and degradation associated with agriculture, charcoal and timber extraction, and frequent fires from anthropogenic sources. In this thesis I combine plot inventory data with remote sensing and modelling techniques to improve our understanding of the miombo woodland C cycle. Using a network of forest inventory plots, I characterise floristic and functional diversity in a savannah-forest mosaic in southeastern Tanzania. Divergent vegetation structures are associated with variation in fire frequency, water supply, and soil chemo-physical properties. Corresponding differences are noted in fire resilience, water-use, and nutrient acquisition plant functional traits, suggesting that multiple interrelated environmental filters act to assemble heterogeneous tree communities. Re-inventory of forest plots was used to quantify key aspects of the woody C cycle. Tree growth rates are slow, calling for careful management of woodland resources, and significantly reduced where stems were damaged. Stem mortality is rare, though elevated in the smallest trees and where damage was recorded. Contemporary strategies to incentivise the conservation of miombo woodland ecosystems, such as the REDD+ programme of the United Nations, advocate payments for sustaining ecosystem services such as C sequestration. I report on a pilot REDD+ project aiming to reduce woodland degradation from frequent high intensity fires in southeastern Tanzania. Model simulations suggest that woody biomass is being gradually lost from the region, and that setting early season fires has the potential to reverse this trend. Realising substantial changes in C storage requires a demanding reduction to late fire frequency, and uncertainty in model predictions remains high. I quantify the C cycle of southern African woodlands by combining observational data with a diagnostic C cycle model under a model-data fusion framework. Model outputs show substantial variation in primary production, C allocation patterns, and foliar and canopy traits, which are associated with differences in woody cover, fire, and precipitation properties. C cycle dynamics correspond poorly to conventional land cover maps, indicating they may be unsuited to upscaling measurements and models of the terrestrial C cycle.
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Morphological and physiological traits as indicators of drought tolerance in tallgrass prairie plantsTucker, Sally Sue January 1900 (has links)
Master of Science / Department of Biology / Jesse B. Nippert / The Konza Prairie in northern Kansas, USA contains over 550 vascular plant species; of which, few have been closely studied. These species are adapted to environmental stress as imposed by variable temperature, precipitation, fire, and grazing. Understanding which plant traits relate to drought responses will allow us to both predict drought tolerance and potential future shifts in plant community composition from changes in local climate. Morphological and physiological measurements were taken on 121 species of herbaceous tallgrass prairie plants grown from seed in a growth chamber. Gas exchange measurements including maximum photosynthetic rate, stomatal conductance to water vapor, and intercellular CO[subscript]2 concentration were measured. All plants were exposed to a drought treatment and were monitored daily until stomatal conductance was zero. At this point, critical leaf water potential (Ψ[subscript]crit), an indicator of physiological drought tolerance was assessed. Other measurements include root length, diameter, volume, and mass, leaf area, leaf tissue density, root tissue density, and root to shoot ratio. Traits were compared using pair-wise bivariate analysis and principal component analysis (PCA). A dichotomy was found between dry-adapted plants with thin, dense leaves and roots, high leaf angle, and highly negative Ψ[subscript]crit and hydrophiles which have the opposite profile. A second axis offers more separation based on high photosynthetic rate, high conductance rate, and leaf angle, but fails to provide a distinction between C[subscript]3 and C[subscript]4 species. When tested independently, grasses and forbs both showed drought tolerance strategies similar to the primary analysis. Matching up these axes with long term abundance data suggests that species with drought tolerance traits have increased abundance on Konza, especially in upland habitats. However, traits that relate to drought tolerance mirror relationships with nutrient stress, confounding separation of low water versus low nutrient strategies. My results not only illustrate the utility of morphological and physiological plant traits in classifying drought responses across a range of species, but as functional traits in predicting both drought tolerance in individual species and relative abundance across environmental gradients of water availability.
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Nature as a template for a new concept of extensive green roofs / La nature comme modèle pour un concept nouveau des toits verts écosystémisésVan Mechelen, Carmen 10 March 2015 (has links)
Au cours de notre ère dite « Anthropocène » et caractérisée par l’urbanisation, la biodiversité est fortement contrainte. Il s’agit d’un problème important car elle est considérée comme le principal moteur du fonctionnement des écosystèmes et comme une source de services écosystémiques. Les toits verts sont un exemple de nouveaux écosystèmes au sein de l’environnement urbain. Ils constituent de nouveaux habitats et peuvent alors limiter la perte de biodiversité en ville. Ils offrent de plus d’autres services écosystémiques comme la régulation thermique, la gestion des eaux pluviales, ainsi qu’une certaine valeur esthétique. Dans cette thèse, nous mettrons notamment l’accent sur les toits verts dit "extensifs" (profondeur du substrat < 20 cm) car ils ont une gamme d'applications plus large et sont plus durables (car autonomes et nécessitant donc moins de maintenance).Dans l’Europe du Sud (région Méditerranéen), les performances des toits verts extensifs sont plutôt faibles, probablement à cause de l'effet des fortes températures et de la sécheresse estivale. On peut même s’attendre à une augmentation du niveau de stress des végétaux des toits verts à cause du changement climatique. La mise en place de systèmes d’irrigation pourrait alors aider en favorisant la croissance des plantes et leur survie. Cependant, cet aménagement est souvent perçu comme une option non soutenable car l'accès à l’eau est limité en région méditerranéenne. Au cours de la période estivale, la pénurie d’eau sera de plus encore plus grave du fait du changement climatique. Par conséquent, une augmentation du nombre de recherches menées sur ce sujet est nécessaire afin de sélectionner les espèces végétales les plus adaptées aux toits verts extensifs non irrigués. Il est également nécessaire d’adapter les éléments structurels des toits extensifs pour mieux répondre aux exigences de ces plantes. Pour les pays plus au nord, avec des climats plus froids (par exemple en climat tempéré maritime), les scénarios de changements climatiques prévoient également une augmentation des températures et des précipitations plus erratiques. Les entreprises de toits végétalisés dans ces régions bénéficieront donc également des résultats d’une telle recherche.L’objectif principal de cette thèse était d’élaborer et de tester un nouveau concept pour la réalisation de toits verts extensifs, comprenant notamment la sélection de la végétation et des éléments de structure (substrat). Le travail est basé sur l’hypothèse de « l’habitat modèle », qui énonce qu’il faut cibler les habitats naturels possédant des caractéristiques similaires aux toits verts extensifs afin de trouver des espèces végétales les plus appropriées. La biodiversité en région Méditerranéenne est très riche et il y a plusieurs habitats qui ressemblent plus au moins aux conditions des toits verts extensifs (sols calcaires et superficielles, drainage rapide, pauvreté en nutriments, fluctuations de température, vents forts). Notre hypothèse est alors qu’il serait possible de trouver des plantes possédant des potentiels pour être introduites sur des toits verts extensifs. Parce que la région Méditerranéenne est très étendue, le sud de la France a été sélectionné comme région d’études. Nous concluons que la végétation méditerranéenne peut être une source d'inspiration pour le développement et l’amélioration de la conception des toits verts extensifs, que ce soit pour le climat méditerranéen actuel ou pour d’autres climats sous l'effet futur des changements climatiques prévus. Un choix de plantes appropriées est alors essentiel, ainsi que la conception en termes de techniques d’irrigation durable, de profondeur et composition du substrat et aussi des possibilités de rétention de l’eau. De plus, il existe encore de nombreuses voies pour la réalisation de recherches supplémentaires qui contribueront à la mise en place de toits verts avec une biodiversité plus importante. / In an era of urbanization, biodiversity is under pressure more than ever. Biodiversity is considered a major driver of ecosystem functioning and the provision of ecosystem services. Green roofs, a prime example of urban novel ecosystems, offer habitats and can hence mitigate some biodiversity loss in cities. Apart from biodiversity, green roofs also offer other ecosystem services, such as thermal regulation, stormwater management, and aesthetic and amenity value. Here we focused on extensive green roofs (substrate depth < 20 cm) as these can be applied widely and are more durable (i.e. less maintenance, self-sustaining). In southern Europe (Mediterranean), the performance of (extensive) green roofs is rather low, probably due to the elevated temperatures and summer drought. One may expect that plant stress on green roofs will further increase as a result of climate change. Irrigation could help plant growth and survival. However, irrigation is often perceived as an unsustainable practice, as water is already a limiting factor in many regions and climate change will lead to an even more severe water scarcity during summer. Therefore, research is needed to select plant species suitable for Mediterranean (unirrigated) extensive green roofs, and to adapt green roof design to meet the requirements of the selected plant species. More northern countries with colder climates (e.g. temperate maritime climate) will also face higher temperatures and erratic precipitation events as a result of climate change. The green roof industries located in these regions will hence also benefit from the outcome of such research. The main goal of this thesis was to elaborate and test a new concept for extensive green roof design, comprising both plant selection and design elements. The work is based on the habitat template theory, which states that natural habitats with similar characteristics as extensive green roofs should be targeted when searching for suitable plant species. Mediterranean regions are a hotspot of biodiversity and contain many habitats that match to some extent the conditions on extensive green roofs (e.g. shallow, free draining, nutrient poor and calcareous soils, high temperature fluctuations, windy). We hence hypothesized that it would be possible to find potential plant species for use on extensive green roofs. Because of practical reasons we selected the southern part of France as study region. At the end of this thesis, we conclude that natural habitats in the Mediterranean region can definitely inspire us as a source for development and improvement of extensive green roof design, whether this is for the current Mediterranean climate itself or for other climates under predicted climate change. Appropriate vegetation choice is essential, as well as the design in terms of sustainable irrigation techniques, appropriate substrate depth and composition, and water retention possibilities. Finally suggestions for further research were made.
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Ecosystem-atmosphere interactions in the Arctic : using data-model approaches to understand carbon cycle feedbacksLópez-Blanco, Efrén January 2018 (has links)
The terrestrial CO2 exchange in the Arctic plays an important role in the global carbon (C) cycle. The Arctic ecosystems, containing a large amount of organic carbon (C), are experiencing ongoing warming in recent decades, which is affecting the C cycling and the feedback interactions between its different components. To improve our understanding of the atmosphere-ecosystem interactions, the Greenland Ecosystem Monitoring (GEM) program measures ecosystem CO2 exchange and links it to biogeochemical processes. However, this task remains challenging in northern latitudes due to an insufficient number of measurement sites, particularly covering full annual cycles, but also the frequent gaps in data affected by extreme conditions and remoteness. Combining ecosystem models and field observations we are able to study the underlying processes of Arctic CO2 exchange in changing environments. The overall aim of the research is to use data-model approaches to analyse the patterns of C exchange and their links to biological processes in Arctic ecosystems, studied in detail both from a measurement and a modelling perspective, but also from a local to a pan-arctic scale. In Paper I we found a compensatory response of photosynthesis (GPP) and ecosystem respiration (Reco), both highly sensitive to the meteorological drivers (i.e. temperatures and radiation) in Kobbefjord, West Greenland tundra. This tight relationship led to a relatively insensitive net ecosystem exchange (NEE) to the meteorology, despite the large variability in temperature and precipitations across growing seasons. This tundra ecosystem acted as a consistent sink of C (-30 g C m-2), except in 2011 (41 g C m-2), which was associated with a major pest outbreak. In Paper II we estimated this decrease of C sink strength of 118-144 g C m-2 in the anomalous year (2011), corresponding to 1210-1470 tonnes C at the Kobbefjord catchment scale. We concluded that the meteorological sensitivity of photosynthesis and respiration were similar, and hence compensatory, but we could not explain the causes. Therefore, in Paper III we used a calibrated and validated version of the Soil-Plant-Atmosphere model to explore full annual C cycles and detail the coupling between GPP and Reco. From this study we found two key results. First, similar metrological buffering to growing season reduced the full annual C sink strength by 60%. Second, plant traits control the compensatory effect observed (and estimated) between gross primary production and ecosystem respiration. Because a site-specific location is not representative of the entire Arctic, we further evaluated the pan-Arctic terrestrial C cycling using the CARDAMOM data assimilation system in Paper IV. Our estimates of C fluxes, pools and transit times are in good agreement with different sources of assimilated and independent data, both at pan-Arctic and local scale. Our benchmarking analysis with extensively used Global Vegetation Models (GVM) highlights that GVM modellers need to focus on the vegetation C dynamics, but also the respiratory losses, to improve our understanding of internal C cycle dynamics in the Arctic. Data-model approaches generate novel outputs, allowing us to explore C cycling mechanisms and controls that otherwise would not have been possible to address individually. Also, discrepancies between data and models can provide information about knowledge gaps and ecological indicators not previously detected from field observations, emphasizing the unique synergy that models and data are capable of bringing together.
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Plant traits as predictors of ecosystem change and function in a warming tundra biomeThomas, Haydn John David January 2018 (has links)
The tundra is currently warming twice as rapidly as the rest of planet Earth, which is thought to be leading to widespread vegetation change. Understanding the drivers, patterns, and impacts of vegetation change will be critical to predicting the future state of tundra ecosystems and estimating potential feedbacks to the global climate system. In this thesis, I used plant traits - the characteristics of individuals and species - to investigate the fundamental structure of tundra plant communities and to link vegetation change to decomposition across the tundra biome. Plant traits are increasingly used to predict how communities will respond to environmental change. However, existing global trait relationships have largely been formulated using data from tropical and temperature environments. It is thus unknown whether these trait relationships extend to the cold extremes of the tundra biome. Furthermore, it is unclear whether approaches that simplify trait variation, such as the categorization of species into functional groups, capture variation across multiple traits. Using the Tundra Trait Team database - the largest tundra trait database ever compiled - I found that tundra plants revealed remarkable consistency in the range of resource acquisition traits, but not size traits, compared to global trait distributions, and that global trait relationships were maintained in the tundra biome. However, trait variation was largely expressed at the level of individual species, and thus the use of functional groups to describe trait variation may obscure important patterns and mechanisms of vegetation change. Secondly, plant traits are related to several key ecosystem functions, and thus offer an approach to predicting the impacts of vegetation change. Notably, understanding the links between vegetation change and decomposition is a critical research priority as high latitude ecosystems contain more than 50% of global soil carbon, and have historically formed a long-term carbon sink due to low decomposition rates and frozen soils. However, it is unclear to what extent vegetation change, and thus changes to the quality and quantity of litter inputs, drives decomposition compared to environmental controls. I used two common substrates (tea), buried at 248 sites, to quantify the relative importance of temperature, moisture and litter quality on litter decomposition across the tundra biome. I found strong linear relationships between decomposition, soil temperature and soil moisture, but found that litter quality had the greatest effect on decomposition, outweighing the effects of environment across the tundra biome. Finally, I investigated whether tundra plant communities are undergoing directional shifts in litter quality as a result of climate warming. Given the importance of litter quality for decomposition, a shift towards more or less decomposable plant litter could act as a feedback to climate change by altering decomposition rates and litter carbon storage. I combined a litter decomposition experiment with tundra plant trait data and three decades of biome-wide vegetation monitoring to quantify change in community decomposability over space, over time and with warming. I found that community decomposability increased with temperature and soil moisture over biogeographic gradients. However, I found no significant change in decomposability over time, primarily due to low species turnover, which drives the majority of trait differences among sites. Together, my thesis findings indicate that the incorporation of plant trait data into ecological analyses can improve our understanding of tundra vegetation change. Firstly, trait-based approaches capture variation in plant responses to environmental change, and enable prediction of vegetation change and ecosystem function at large scales and under future growing conditions. Secondly, my findings offer insight into the potential direction, rate and magnitude of vegetation change, indicating that despite rapid shifts in some traits, the majority of community-level trait change will be dependent upon the slower processes of migration and species turnover. Finally, my findings demonstrate that the impact of warming on both tundra vegetation change and ecosystem processes will be strongly mediated by soil moisture and trait differences among vegetation communities. Overall, my thesis demonstrates that the use of plant traits can improve climate change predictions for the tundra biome, and informs the fundamental rules that determine plant community structure and change at the global scale.
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Differences in plant trait distribution in semi-natural grassland habitats of SwedenVepsäläinen, Viivi January 2020 (has links)
Habitat type has been suggested to be a major factor contributing to differencesin plant trait distribution of grassland habitats. Land use changes in agricultural landscapes have affected the available habitats and the dispersal ability of plants, which may effect plant trait diversity of agricultural landscapes. Little is also known about the effects of landscape openness on plant trait diversity. This study analysed differences in plant traits between different semi-natural grassland habitats in agricultural landscapes in four different regions in Sweden: Skåne, Södermanland, Gävleborg, and Norrbotten. The following research questions were used: (1) How does landscape openness (the amount of open andarable land found in a landscape) affect plant trait values collected from a new database in semi-natural grassland habitats in agricultural landscapes? (2) How does the type of habitat affect plant trait values in semi-natural grassland habitats in agricultural landscapes? (3) How does geographical location in Sweden affect plant trait values in semi-natural grassland habitats in agricultural landscapes? Overall 12 landscapes in each region were surveyed for plant data using 20 sample plots in each landscape. Trait values for biodiversity relevance, nectar production, nitrogen, phosphorus, grazing/mowing, soil disturbance, longevity, pollinator dependence, and seed dispenser were assigned for each plant species based on an external database, and average trait values were calculated for each of the studied traits in each sample. Kruskal-Wallis test andANOVA were performed on average trait values to identify differences between each habitat types and regions. Besides the effect of habitat type, the effect of openness in the landscape on the chosen traits was analysed with Spearman’s and Pearson’s correlations. The results revealed differences between habitat types in almost all studied traits: grazed habitats had plants with higher biodiversity relevance but lower nectar production. Differences were also found between the southern and northern regions. More open landscapes had plants with higher biodiversity relevance as well as higher tolerance for both nitrogen and phosphorus. Less open landscapes had higher tolerance for grazing/mowing and higher nectar production. The results of this study therefore support earlier findings of the importance of habitat in plant trait distribution of grassland habitats.
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The potential of multispectral imaging flow cytometry for environmental monitoringDunker, Susanne, Boyd, Matthew, Durka, Walter, Erler, Silvio, Harpole, W. Stanley, Henning, Silvia, Herzschuh, Ulrike, Hornick, Thomas, Knight, Tiffany, Lips, Stefan, Mäder, Patrick, Motivans Švara, Elena, Mozarowski, Steven, Rakosy, Demetra, Römermann, Christine, Schmitt-Jansen, Mechthild, Stoof-Leichsenring, Kathleen, Stratmann, Frank, Treudler, Regina, Virtanen, Risto, Wendt-Potthoff, Katrin, Wilhelm, Christian 07 December 2023 (has links)
Environmental monitoring involves the quantification of microscopic cells and particles
such as algae, plant cells, pollen, or fungal spores. Traditional methods using conventional
microscopy require expert knowledge, are time-intensive and not wellsuited
for automated high throughput. Multispectral imaging flow cytometry (MIFC)
allows measurement of up to 5000 particles per second from a fluid suspension and
can simultaneously capture up to 12 images of every single particle for brightfield
and different spectral ranges, with up to 60x magnification. The high throughput of
MIFC has high potential for increasing the amount and accuracy of environmental
monitoring, such as for plant-pollinator interactions, fossil samples, air, water or food
quality that currently rely on manual microscopic methods. Automated recognition of
particles and cells is also possible, when MIFC is combined with deep-learning computational
techniques. Furthermore, various fluorescence dyes can be used to stain
specific parts of the cell to highlight physiological and chemical features including:
vitality of pollen or algae, allergen content of individual pollen, surface chemical composition
(carbohydrate coating) of cells, DNA- or enzyme-activity staining. Here, we
outline the great potential for MIFC in environmental research for a variety of
research fields and focal organisms. In addition, we provide best practice
recommendations.
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Faktory určující rozšíření druhů suchých trávníků / Factors determining distribution of species in dry grasslandsPrůchová, Dana January 2010 (has links)
Factors determining distribution of species in semi-natural grasslands Survival and colonization of plant species in fragmented landscapes are topic of many recent studies. Most of them deal with one or just a few species or with overall species diversity. There are also a lot of studies devoted to the effect of abiotic characteristics and other parameters of fragmented habitat patches. Studies that would enable to evaluate behaviour of a large number of individual species are still relatively rare, especially in case of grassland species. Comparison of species traits in conjunction with the knowledge of type of historical land use and abiotic requirements of species can be a key to understanding of current species dispersal and their regional dynamic in fragmented landscape. This method of prediction of species dispersal can be a good implement for landscape planning and conservation of species and also their habitats. Goal of my thesis was to determine which traits of species influence response of species on land-use history in fragmented habitat of dry grasslands. I tried to use effect of land-use history without effect of environmental factors on species composition in phytosociological relevés. Then I tried to explain the reaction of species through their traits. I focused partially on traits...
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Содержание азота и фосфора в листьях однодольных растений с разными способами почвенного питания : магистерская диссертацияРеутова, Н. А., Reutova, N. A. January 2024 (has links)
This research is devoted to the study of nitrogen and phosphorus content in leaves of annual plants. The aim of the present work is to investigate the nitrogen and phosphorus content in leaves of annual plants of five families (Poaceae, Cyperaceae, Orchidaceae, Iridaceae and Amaryllidaceae), which have different adaptations to soil nutrition. In order to achieve the objective, the following objectives have been identified: 1) to determine the availability of N and P for plants in natural conditions and ways of soil nutrition of the studied families of annuals according to the literature data. 2) to determine the content of N and P in the leaves of the studied families of annuals. 3) to reveal the regularities of N and P content in leaves of monocotyledonous plants depending on taxonomic position, belonging to ecological and cenotic group and type of ecological strategy. 4) determine the relationship of soil nutrition methods with the content of N and P in leaves of annual plants. N and P content in leaves was analysed on 41 species of annual plants growing in natural communities (Biological Station of UrFU, forests of Staroutkinsk settlement, territories of Khanty-Mansi Autonomous Okrug) and in botanical gardens of UrFU and Ural Branch of the Russian Academy of Sciences (Ekaterinburg). Also, in order to identify the relationship between the content of N and P in leaves from fertiliser application, an experiment was conducted on Avena sativa. Determination of total nitrogen content was carried out according to the Kjeldahl method using Heating Digestor DK 20. For the analysis of plant material was adapted to the method of determination of gross phosphorus in soils, adopted by the standard GOST 26261 84 «Soils. Methods of determination of gross phosphorus and potassium». As a result of the conducted research, it was found that N and P content is related to taxonomic affiliation and to a lesser extent to ecological and cenotic type of species and is not related to ecological strategy. No differences in N and P content in leaves of fertilised and unfertilised plants were found. Belonging to one or another family in the studied species of annuals is closely related to the ability to mycorrhiza formation and the type of mycorrhiza, which explains the specificity of element content. / Данная работа посвящена изучению содержания азота и фосфора в листьях однодольных растений. Цель настоящей работы — исследовать содержание азота и фосфора в листьях однодольных растений пяти семейств (Poaceae, Cyperaceae, Orchidaceae, Iridaceae и Amaryllidaceae), которые имеют разные приспособления к почвенному питанию. Для достижения поставленной цели были выделены следующие задачи: 1) по литературным данным определить доступность N и P для растений в естественных условиях и способы почвенного питания исследуемых семейств однодольных. 2) определить содержание N и P в листьях исследуемых семейств однодольных. 3) выявить закономерности содержания N и P в листьях однодольных растений в зависимости от таксономического положения, принадлежности к эколого-ценотической группе и типу экологической стратегии. 4) установить связь способов почвенного питания с содержанием N и P в листьях однодольных растений. Анализ содержания N и P в листьях проводился на 41 виде однодольных растений, произрастающих в естественных сообществах (Биологическая станция УрФУ, леса п. Староуткинска, территории ХМАО) и в ботанических садах УрФУ и УрО РАН (г. Екатеринбург). Также с целью выявления связи между содержанием N и P в листьях от внесения удобрений был проведен эксперимент на Avena sativa. Определение содержания общего азота проводилось по методу Къельдаля с использованием блока Heating Digestor DK 20. Под анализ растительного материала была адаптирована методика определения валового фосфора в почвах, принятая стандартом ГОСТ 26261 84 «Почвы. Методы определения валового фосфора и калия». В результате проведённого исследования установлено, что содержание N и P связано с таксономической принадлежностью и в меньшей степени с эколого ценотическим типом вида и не связано с экологической стратегией. Различия в содержании N и P в листьях удобренных и неудобренных растений не обнаружены. Принадлежность к тому или иному семейству у изученных видов однодольных тесно связано со способностью к микоризообразованию и типом микоризы, что объясняет специфику содержания элементов.
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