Academic literature on the topic 'Biotic factors'
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Journal articles on the topic "Biotic factors"
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NINGSIH, SRI WAHYU, Achyani Achyani, and Handoko Santoso. "FAKTOR BIOTIK DAN ABIOTIK YANG MENDUKUNG KERAGAMAN TUMBUHAN PAKU(Pteridophyta) DI KAWASAN HUTAN GISTING PERMAI KABUPATEN TANGGAMUS LAMPUNG." BIOLOVA 2, no. 1 (2021): 64–71. http://dx.doi.org/10.24127/biolova.v2i1.293.
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ABSTRACT: Tumbuh suburnya Pteridophyta di Kawasan Hutan Gisting Permai Kecamatan Gisting Kabupaten Tanggamus sangat dipengaruhi oleh faktor biotik dan abiotik. Faktor biotik meliputi semua kehidupan makhluk hidup di bumi baik individu, populasi dan komunitas yang di dalamnya termasuk jumlah inang Pteridophyta yang banyak, sedangkan faktor abiotik meliputi seluruh faktor-faktor non hidup dari suatu kondisi lingkungan seperti cahaya matahari, suhu, air, dan tanah, ketinggian. Faktor-faktor abiotik ini tidak hanya menyediakan energi dan materi penting, tetapi juga mempunyai peranan dalam menentukan tumbuhan-tumbuhan dan hewan-hewan yang mampu berada disuatu tempat tertentu sesuai dengan habitatnya. Metode yang digunakan dalam kajian ini adalah berupa kajian kualitatif. Artikel ini dikaji dengan menyatukn referensi dari berbagai sumber diantaranya berasal dari jurnal, buku, arsip dokumen pekon Gisting Permai, dan internet. Pengumpulan data diperoleh dengan menggunakan berbagai referensi yang dikumpulkan sebanyak mungkin yang berkaitan dengn faktor biotik dan abiotik pertumbuhan tumbuhan paku.
 
 Kata kunci: Biotik, Abiotik, Pteridophyta.
 
 ABSTRACT: The growth of Pteridophyta in the Permai Gisting Forest Area, Gisting Sub-District Tanggamus Regency was strongly influenced by biotic and abiotic factors. Biotic factors include all the life of living things on earth both individuals, populations and communities which include a large number of Pteridophyta hosts, while abiotic factors include all non-living factors of an environmental condition such as sunlight, temperature, water, and soil, height. These abiotic factors not only provide important energy and material, but also had a role in determining plants and animals that which are able to be in a certain place according to their habitat. The method used in this study is a qualitative study. This article was reviewed by citing references from various sources including journals, books, Gisting Permai archive documents, and the internet. The data collection was obtained by using as many references as possible related to biotic and abiotic factors for fern growth.
 
 
 Key word: biotic, abiotic, Pteridophyta.
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Main, Christopher L., Lawrence E. Steckel, Robert M. Hayes, and Thomas C. Mueller. "Biotic and abiotic factors influence horseweed emergence." Weed Science 54, no. 6 (2006): 1101–5. http://dx.doi.org/10.1614/ws-06-026r1.1.
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Meshkova, Valentyna, Olena Kuznetsova, Oleksandr Borysenko, Volodymyr Korsovetskyi, and Tetiana Pyvovar. "Biotic Factors Affecting Elm Health in Ukraine." Forests 15, no. 12 (2024): 2209. https://doi.org/10.3390/f15122209.
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Elms (Ulmus spp.) are widely spread in the forest, shelter belts, and urban landscaping. This research aimed to reveal the trends of Ulmus sp. health in Ukraine under biotic damage. The tasks included: (i) analyzing the presence of Ulmus sp. in the forests; (ii) studying the dynamics of Ulmus sp. health for 2001–2015 in the monitoring plots in the frame of the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests); (iii) assessing the prevalence of the dominant biotic factors affecting elm health and the probability of tree death or recovery. As a result of research, elms were found in 3.58% of the area in the stands with other main forest-forming species in the forests subordinated to the State Specialized Forest Enterprise «Forests of Ukraine». Four elm species are present in the forests of all regions of Ukraine. In the Forest zone, U. minor predominates, U. glabra is more common in the western part of the country, and U. pumila in the southern and eastern regions. In the ICP-Forests monitoring plots for 2001–2015, a trend of elm deterioration in 2007–2012 was found. The highest incidence of trees with disease symptoms was recorded for U. pumila. In the sample plots for 2023–2024, the health of three elm species tended to deteriorate. In 2024, mortality occurred among all elm species with symptoms of Dutch elm disease (DED) and among U. pumila trees with symptoms of wetwood. However, several trees have recovered. The results show the gaps in our knowledge that need to be filled, particularly in identifying resistant individuals and using their progeny to create resistant stands.
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Saleh, Abdelaty, and Montserrat Pagés. "Plant AP2/ERF transcription factors." Genetika 35, no. 1 (2003): 37–50. http://dx.doi.org/10.2298/gensr0301037s.
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Transcription factors (TFs) play important roles in plant development and its response to the biotic and abiotic stresses. AP2/ERF transcription factors family is unique to plants and a conserved AP2/ERF domain of about 60 amino acids characterized these transcription factors. AP2/ERF genes have been shown to regulate developmental processes and the response of plants to various types of biotic and environmental stress. Here, we summarize the current knowledge of AP2/ERF plant transcription factor family.
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Kumar, Rakesh, and Vinod Kumar. "A review of phylogeography: biotic and abiotic factors." Geology, Ecology, and Landscapes 2, no. 4 (2018): 268–74. http://dx.doi.org/10.1080/24749508.2018.1452486.
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El Amrani, Belkacem. "Insights into the Biotic Factors Shaping Ectomycorrhizal Associations." Biology 13, no. 12 (2024): 1044. https://doi.org/10.3390/biology13121044.
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Ectomycorrhizal (EM) associations are essential symbiotic relationships that contribute significantly to the health and functioning of forest ecosystems. This review examines the biotic factors that influence EM associations, focusing on plant and fungal diversity, host specificity, and microbial interactions. Firstly, the diversity of host plants and ectomycorrhizal fungi (EMF) is discussed, highlighting how the richness of these organisms affects the formation and success of EM symbioses. Next, host specificity is explored, with a focus on the complex relationships between EMF and their host plants. Microbial interactions are examined in depth, with sections on both positive and negative influences of bacteria and different fungal groups on EM formation. Overall, this review provides a comprehensive overview of the biotic factors that shape EM associations, offering insights into the mechanisms that underpin these critical ecological interactions and their broader implications for ecosystem management and restoration.
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Martínez-Álvarez, Rosa M., Amalia E. Morales, and Ana Sanz. "Antioxidant Defenses in Fish: Biotic and Abiotic Factors." Reviews in Fish Biology and Fisheries 15, no. 1-2 (2005): 75–88. http://dx.doi.org/10.1007/s11160-005-7846-4.
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THIELTGES, D. W., K. T. JENSEN, and R. POULIN. "The role of biotic factors in the transmission of free-living endohelminth stages." Parasitology 135, no. 4 (2008): 407–26. http://dx.doi.org/10.1017/s0031182007000248.
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SUMMARYThe transmission success of free-living larval stages of endohelminths is generally modulated by a variety of abiotic and biotic environmental factors. Whereas the role of abiotic factors (including anthropogenic pollutants) has been in focus in numerous studies and summarized in reviews, the role of biotic factors has received much less attention. Here, we review the existing body of literature from the fields of parasitology and ecology and recognize 6 different types of biotic factors with the potential to alter larval transmission processes. We found that experimental studies generally indicate strong effects of biotic factors, and the latter emerge as potentially important, underestimated determinants in the transmission ecology of free-living endohelminth stages. This implies that biodiversity, in general, should have significant effects on parasite transmission and population dynamics. These effects are likely to interact with natural abiotic factors and anthropogenic pollutants. Investigating the interplay of abiotic and biotic factors will not only be crucial for a thorough understanding of parasite transmission processes, but will also be a prerequisite to anticipate the effects of climate and other global changes on helminth parasites and their host communities.
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Anandham, Rangasamy, and Tongmin Sa. "Editorial for Special Issue “Environmental Factors Shaping the Soil Microbiome”." Applied Sciences 11, no. 21 (2021): 10387. http://dx.doi.org/10.3390/app112110387.
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Soil is a complex system consisting of various abiotic and biotic factors interacting among themselves in a particular time period. These biotic factors are particularly affected by a large number of disturbances or perturbations occurring in the micro-niches. Soil microbiome is the paramount biotic factor responsible for nutrient cycling that in turn determines soil health and quality. However, there are limitations in studying soil systems as there are a number of unknown boxes that need to be checked before understanding their full-fledged contribution to the environment. The microbial diversity in the soil can be affected by salinity, contaminant, fertilization, nutrient accumulation, and cultivation practices. Additionally, plants can also benefit from these changes in microbial community composition, and novel microbial isolates can be used for enhancing their growth under various stress conditions. Collectively, this Special Issue includes various studies that determine key abiotic and biotic factors that can result in changes in microbial community composition in the soil system. These studies are carried out in specified environmental niches rather than microcosms, which provides a broader context in which to understand microbial dynamics.
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Pathak, Hom N. "Biotic Resistance and Fluctuating Resources: Key Factors for Invasion Success?" Multi-Disciplinary Explorations: The Kasthamandap College Journal 2, no. 2 (2024): 73–82. https://doi.org/10.3126/mdekcj.v2i2.74178.
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To explain the process of biological invasion, several hypotheses have been put forward e.g. enemy release hypothesis, invasional meltdown hypothesis, novel weapon hypothesis, fluctuation resources hypothesis, biotic resistant hypothesis, etc. I collected the abstracts from search engines on the internet. I searched for biotic resistance and fluctuation resources hypotheses, collected 25 research papers, and reviewed them. Out of nine studies written for the biotic resistance hypothesis, five were in support and the other five were against the hypothesis. However, there seems only evidence against the fluctuation resources hypothesis. For it, I found four articles in support of this hypothesis. Any hypothesis alone cannot explain the causes behind the invasion's success. Therefore, I have an opinion to establish a combined theory for it.
Dissertations / Theses on the topic "Biotic factors"
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MacDonald, Arthur Andrew Meahan. "Abiotic and biotic factors creating variation among bromeliad communities." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58954.
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Many ecological communities show variation from place to place; understanding the causes of this variation is the goal of community ecology. Differences in community composition will be the result of both stochastic and deterministic processes. However, it is difficult to know to what degree deterministic processes will shape community composition. In this thesis I combined observational and experimental approaches to quantify deterministic processes within a particular ecological community -- they phytotelmata of bromeliad plants. In my thesis I describe three studies at different scales of organization: 1) do organisms of different size respond equally to changes in their environment 2) how do predators interact to influence prey survival 3) what mechanisms underly the response of similar species to the same environmental gradient, bromeliad size. In Chapter 1, I tested an hypothesis developed from previous observational data -- that smaller organisms respond less than larger ones to the same environmental gradient -- different bromeliad species that occur under different forest canopies. After removing variation caused by dispersal, I found that environmental variation explained little variation for bacteria, more for zooplankton and most of all for macroinvertebrates. In my second chapter, I examined ecological determinism on a smaller scale -- within a single trophic level (macroinvertebrate predators). I found that predators may interfere with each other, reducing predation rates and increasing prey survival. In Chapter 3, I examine macroinvertebrate responses to bromeliad volume. I use both null models and a field experiment to show that for at least one such pair, a difference in abiotic tolerances may be the plausible mechanism. Together these results illustrate when, and to what degree, bromeliad communities respond to deterministic factors. All three chapters first demonstrate a pattern, testing it against a suitable null distribution, before attempting to quantify possible mechanisms with a field experiment. This combination of observation and experiment is an approach which can contribute to our understanding of how ecological systems work.<br>Science, Faculty of<br>Graduate
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Black, Kyrsten E. "Root longevity as affected by biotic and abiotic factors." Thesis, University of Aberdeen, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361797.
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Roots and their associated mycorrhizal fungi have long been recognised as major determinants of nutrient cycling. Their measurement has been limited because soil limits accessibility. The use of <I>in-situ</I> camera techniques in conjunction with minirhizotrons and image analysis software now make the acquisition of accurate root longevity data possible. The current literature was reviewed in relation to root longevity - both measurement techniques and available data. Four main experiments were employed to study the root longevity of a number of tree species, grass and clover subject to differing environmental conditions and grass and clover and poplar roots with and without colonisation by Arbuscular Mycorrhizal fungi. The data was analysed in a number of different ways including the use of the powerful statistical technique for censored data - survival analysis. This technique proved to be very useful for analysing temporal changes to root longevity. The data indicate that root longevity can be extremely short but is dependent upon environment and for some species, colonisation by Arbuscular Mycorrhizal fungi. Preliminary calculations were completed to determine the role of root death in nutrient cycling and these predict that large quantities of nitrogen, phosphorus and carbon are flowing from the live to the dead root pool on an annual basis.
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Gerald, Gary Wayne II. "Consequences of abiotic and biotic factors on limbless locomotion." Miami University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=miami1218208497.
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Jones, Lisa. "The role of biotic and abiotic factors in exotic species replacement." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114198.
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Biological invasions are a major component of global environmental change and are increasing in frequency. Most community-level impact studies of invasions are concerned with interactions between exotic and native species. However, interactions among exotic species are becoming increasingly common, potentially altering their respective impacts on invaded ecosystems. This research identifies one possible outcome of such interactions: the growing phenomenon of 'exotic species replacement', whereby a newly arriving exotic species surpasses the abundance of a functionally similar incumbent exotic species. This phenomenon is explored here using two Eurasian dreissenid bivalves that invaded the St. Lawrence River in the early 1990s, the zebra mussel (Dreissena polymorpha) and quagga mussel (D. bugensis). I review the general replacement pattern of the zebra mussel by its congener, and examine environmental factors and life history traits that mediate this replacement in a navigational canal connected to the river. Since the 1990s, quagga mussels have replaced the zebra mussel as the dominant dreissenid mussel, but the contemporary adult distribution and abundance is spatially structured: quagga mussels dominate the deep zone, while zebra mussels remain common in the shallow margins of the canal. Field surveys and in situ field experiments are used to examine the relative importance of pre-settlement, settlement and post-settlement processes, in the context of life history trade-offs and environmental gradients, in determining patterns of adult mussel distribution and abundance. Despite the potential importance of larval supply and behavior, including substrate selection at settlement, none of these processes determined adult dreissenid distribution and abundance. Rather, the main determinants were post-recruitment processes involving condition-specific competition. Adult zebra mussels generally had lower body condition, growth, shell length, and survivorship than quagga mussels, and these differences were most pronounced in the deep zone of the canal. This case highlights the importance of subtle differences in life history and abiotic tolerances among closely-related species in understanding changing patterns of distribution and abundance in an invaded community.<br>Les invasions biologiques sont une composante majeure des changements environnementaux au niveau mondiale et leurs fréquences continuent à augmenter. La plupart des études sur l'impact des invasions à l'échelle communautaire s'intéressent principalement aux interactions entre les espèces exotiques et indigènes. Par contre, on observe de plus en plus des interactions entre des espèces exotiques, ce qui pourrait modifier leurs impacts respectifs sur les écosystèmes envahis. Cette recherche a pour but d'examiner le 'remplacement d'espèces exotiques', un phénomène par lequel l'abondance d'une espèce exotique nouvellement arrivée surpasse l'abondance d'une espèce exotique déjà présente et dominante, qui possède également une similarité fonctionnelle. Ce phénomène est exploré ici à l'aide de deux bivalves Eurasiennes de la famille des Dreissenidés qui ont envahi le fleuve Saint-Laurent au début des années 1990, la moule zébrée (Dreissena polymorpha) et la moule quagga (D. bugensis). J'examine le schéma général de remplacement de la moule zébrée par son congénère dans un canal de navigation relié au fleuve. J'examine également les facteurs environnementaux et les traits d'histoire de vie de ces moules qui peuvent influencer se remplacement. Depuis les années 1990, la moule quagga a remplacé la moule zébrée en tant que le dreissenidé dominant. Par contre, la distribution et l'abondance contemporaines des adultes sont structurées de façon spatiale: les moules quagga dominent la zone profonde, tandis que les moules zébrées demeurent communes dans la région peu profonde du canal. Des études sur le terrain et des expériences in situ ont été utilisées pour examiner l'importance relative des processus de pré-établissement, d'établissement et de post-établissement, sur la distribution et l'abondance des moules adultes. Malgré l'importance potentielle de l'approvisionnement et du comportement larvaire, y compris la sélection du substrat durant l'établissement, aucun de ces processus ne joue un rôle important dans la détermination de l'abondance et la distribution des dreissenidés adultes. Plutôt, les principaux facteurs déterminants étaient les processus de post-recrutement impliquant la compétition mediée par l'environnement. En générale, la condition, la croissance, la longueur de coquille et la survie des moules zébrées adultes étaient inférieures à celles des moules quagga, et ces différences étaient plus prononcées dans la zone profonde du canal. Cette étude met en valeur l'importance des différences subtiles des traits d'histoire de vie et des tolérances abiotiques d'espèces étroitement liées dans la compréhension des schémas changeants de distribution et d'abondance d'individus dans les communautés envahies.
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Ford, Tiiu Kirsti 1972. "Biotic Factors and Temperature Tolerances via Critical Thermal Methodology in Goldfish." Thesis, University of North Texas, 1999. https://digital.library.unt.edu/ark:/67531/metadc279125/.
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CTMinimum and CTMaximum were measured in 620 goldfish to determine if biotic factors, in particular starvation, condition factor and size, affect temperature tolerance. Twenty-eight days of starvation adversely affected both upper and lower temperature tolerance. Condition factor was related to upper but not lower temperature tolerance.
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Urbina, Barreto Ifigenia. "Abiotic and biotic factors determining the nutrient stoichiometry of contrasting terrestrial ecosystems." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/667763.
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Todo en la tierra es química. Esta afirmación tiene profundas implicaciones para las interacciones ecológicas. Los organismos vivos promueven y controlan flujos de materia y energía entre la atmosfera, hidrosfera y litosfera; modificando la composición química de la tierra de muchas maneras diferentes. La estequiometría ecológica estudia el balance y el papel de múltiples elementos químicos en las interacciones ecológicas y nos ayuda a entender patrones y procesos en la naturaleza. Representa el enlace entre la biogeoquímica y el funcionamiento de los ecosistemas, permitiéndonos describir procesos a todos los niveles de organización biológica, desde estructuras sub-celulares a ecosistemas.
En esta Tesis he usado la estequiometría ecológica para describir procesos a nivel de organismo y ecosistema en tres condiciones ambientales terrestres diferentes. La estequiometría de los autótrofos se establece cuando estos usan luz para fijar carbono (C) y simultáneamente asimilan nutrientes. Las plantas son capaces de almacenar nutrientes en la vacuola intracelular y en diferentes órganos, lo que hace que su estequiometría sea muy flexible (baja homeostasis) y se adapten a diferentes ambientes, incluyendo condiciones del suelo limitantes para el desarrollo de las plantas. También, la interacción planta suelo se puede explorar a través de la estequiometría foliar, ya que se ha demostrado en todos los ecosistemas terrestres que el N:P foliar esta correlacionado positivamente con el N:P del suelo, sugiriendo que es un buen indicador de la disponibilidad de nutrientes.
Las adaptaciones de las plantas a condiciones limitantes de nutrientes en el suelo son comunes en todos los ecosistemas terrestres, como es la fijación de nitrógeno, la asociación con micorrizas, producción de fosfatasas o la reabsorción de nutrientes desde las hojas senescentes para el reciclado interno de nutrientes. La composición elemental de las especies es afectada por esas interacciones abióticas y bióticas, y el intercambio de elementos químicos entre las especies y el espacio abiótico determinaran la composición elemental de las diferentes partes del ecosistema.
En el Capítulo 2 exploramos el efecto biótico de la composición de las comunidades sobre la composición química foliar de distintas especies vegetales, a través del nicho biogeoquímico de cada especie. Encontramos que cada especie presenta su propio nicho biogeoquímico y fueron capaces de reajustar su composición química foliar en respuesta a las diferentes condiciones bióticas. Concluimos que las plantas pueden reajustar su composición elemental foliar cuando crecen en comunidades con diferente composición de plantas, a través del desplazamiento del nicho biogeoquímico, sugiriendo un uso diferencial de los recursos cuando los patrones de coexistencia cambian.
En el Capítulo 3 hemos explorado el cambio en la composición química del sistema planta-suelo debido a la expansión de arbustos en los pastizales subalpinos del Pirineo. Esta expansión representa la transición desde pastizales puros a matorrales. Los pastizales son un ecosistema dominado por especies de ciclo de vida corto, rápido intercambio de nutrientes entre los compartimientos planta-suelo, altas concentraciones de nitrógeno (N), fósforo (P) y potasio (K) en el sistema planta-suelo, con alta productividad pero capacidad limitada de acumulación de biomasa. En cambio, los matorrales se caracterizan por ser un ecosistema dominado por especies de ciclo de vida largo, con estrategias más conservativas, con un intercambio de nutrientes más lento (relación de C:nutrientes altos en la biomasa aérea y baja concentración de N y P en el sistema planta-suelo) y mayor almacenamiento de nutrientes en la biomasa aérea de las plantas. La matorralización incrementa la dependencia de la adquisición de nutrientes como el N a través de micorrizas desde los pastizales puros a matorrales. Todos los cambios en el almacenamiento y composición elemental del sistema planta-suelo a lo largo de la sucesión desde pastizales a matorrales sugiere una desaceleración del ciclo biogeoquímico en las áreas montañosas donde la expansión de arbustos está presente.
En el Capítulo 4, describimos la distribución de C y los nutrientes más importantes para el desarrollo de las plantas (N, P, K) en el sistema planta-suelo de bosques tropicales maduros en suelos pobres de la Guyana Francesa. También estudiamos el proceso de reabsorción de nutrientes desde las hojas senescentes, un mecanismo de nutrición de las plantas para evitar la perdida de nutrientes poco estudiado en este ecosistema. Nuestros resultados muestran que el P es el elemento más escaso presente en hojas, hojarasca y suelo. Las eficiencias de reabsorción de K y P fueron más altas que la de N y la estacionalidad solo afecto la reabsorción de K. La reabsorción de P fue la única que mostró una correlación, aunque débil, con el P en el suelo (total y disponible). Las relaciones entre la reabsorción de nutrientes y los rasgos funcionales de las especies (tasa de crecimiento, densidad de madera, diámetro a la altura del pecho y el área foliar específica) fueron débiles y variaron dependiendo del nutriente, en tanto que la relación filogenética no explica la variabilidad en las eficiencias de reabsorción de nutrientes de las especies. Nuestros resultados sugieren que la alta reabsorción de K y P desde las hojas senescentes es una estrategia adaptativa de las especies que les permite lidiar con la escasez de estos nutrientes en el suelo. Asimismo, el nivel de inmovilización de los nutrientes en los compuestos foliares (N > P > K) parece determinar significativamente el proceso de reabsorción. Concluimos que la reabsorción de nutrientes desde las hojas senescentes es un proceso clave de las plantas para la conservación de nutrientes en los bosques tropicales de la Guyana Francesa, especialmente para K y P, elementos que presentan una disponibilidad baja en el suelo, y esta depende principalmente del material parental y del proceso de lixiviación.
En resumen, en esta Tesis hemos demostrado como la composición elemental del sistema planta-suelo refleja procesos e interacciones ecológicas, como son las interacciones intra e inter específica entre plantas (Capítulo 2), procesos fisiológicos poco estudiados en las plantas como la reabsorción de nutrientes (Capítulo 4) y la importancia de los estudios de estequiometría para describir cambios a nivel de ecosistema y predecir escenarios futuros (Capítulo 3). Estos estudios aportan nuevos conocimientos en el campo de la estequiometría ecológica y resaltan la importancia de este enfoque en los estudios ecológicos.<br>Everything on Earth is based on chemistry. This statement has profound implications for ecological interactions. Living organisms generate and control fluxes of energy and matter among the atmosphere, lithosphere and the hydrosphere, shaping the chemistry of the Earth in many different ways. Ecological stoichiometry aims to explore the balance and role of multiple chemical elements in ecological interactions and help us to understand patterns and processes in nature. It represents the link between the biogeochemistry and the ecosystems’ function and allows to describe processes across different levels of biological organization, from cellular structures to ecosystems.
In this Thesis I use ecological stoichiometry to describe processes at organism and ecosystem levels in three contrasting terrestrial environment conditions. Autotrophs’ stoichiometry is established when these organism use light to fix carbon (C) and simultaneously assimilate nutrients. Plants are able to store nutrients in the cells’ vacuole and in different organs, which make them highly flexible (less homeostatic) in terms of their elemental composition. This feature explains the high adaptability of plants to different environments, including soil nutrient limitation conditions. Furthermore, plant-soil interaction could be explored through the foliar stoichiometry, because it has been shown that the foliar N:P is positive correlated with the N:P of soil in all terrestrial ecosystem, suggesting that foliar stoichiometry is a good indicator of the resource availability.
Plant adaptations to soil nutrient limiting conditions are quite common in all terrestrial ecosystems, such as nitrogen fixation, mycorrhiza association, production of phosphatases and nutrient resorption before leave abscission. The species’ chemical composition is affected by all these abiotic and biotic interactions, and these exchange of chemical elements between the species and the abiotic part of the system determine the elemental composition of different components of the ecosystems.
In Chapter 2, we explore the biotic effect of the community composition on the species foliar stoichiometry, taken as a proxy of the species’ biogeochemical niche. We found that each species has its own biogeochemical niche and is able to readjust its chemical composition in response to different biotic conditions. We conclude that plants can readjust their foliar element composition when they grow in communities with contrasting plant composition through the biogeochemical niche displacement, suggesting a differential use of the resources when the patterns of species coexistence change.
In Chapter 3 we explore the plant-soil stoichiometry changes due the shrub expansion into the subalpine grassland in the Pyrenees. Shrub expansion had a clear impact on the plant-soil stoichiometry spectrum. This expansion represents the transition from pure grassland to shrubland. The grassland is an ecosystem dominated by short-lived species, fast nutrient turnover between the plant-soil compartments, high nitrogen (N), phosphorus (P) and potassium (K) concentrations in the plant-soil system, high productivity but low biomass stocks. The shrubland is an ecosystem characterized by long-lived species with more conservative strategy, slow nutrient turnover (low N and P concentrations in the plant-soil compartments, high C:nutrient ratios in the aboveground biomass) and high stocks of C and nutrients in the plant aboveground biomass. Shrub encroachment increase the acquisition of N through mycorrhizal associations. The changes in storage and elemental composition of the plant soil system along the succession from grassland to shrubland suggests that there is a slowdown of the biogeochemical cycle in the subalpine mountain areas where shrub encroachment occurred.
In the Chapter 4, we describe the distribution of C and the most important nutrients for the plant development (N, P, K) in the plant and soil compartments in old-growth tropical forests growing in nutrient-poor soil in French Guiana. We also studied the nutrient resorption from senescent leaves, a poorly explored mechanism that plants use to avoid losing nutrients in this ecosystem. Our results showed that P was the scarcest nutrient in the leaf, leaf-litter and soil. Resorption efficiencies were higher for K and P than for N, and only K resorption efficiency was affected by seasonality. P resorption showed a negative and weak correlation with P in soil (total and available). Relationships between nutrient resorption and species functional characteristics (growth rate, wood density, diameter at breast height and specific leaf area) were weak and varied among the nutrients, and phylogenetic relatedness did not account for the variability in resorption efficiencies. Our results suggest that high K and P resorption from senescent leaves is an adaptive strategy allowing species to cope with soil nutrient scarcity. Furthermore, the level of nutrient immobilization in foliar compounds (N > P > K) seem to significantly determine the resorption process. We conclude that nutrient resorption from senescent leaves is a key process for plants to conserve nutrients in tropical forests of French Guiana, especially for K and P, where soil availabilities are low and depend mainly on soil parent material and leaching process.
To sum up, in this Thesis we have demostrated how the elemental composition of the plant-soil system reflects ecological interactions and processes, such as intra and inter specific plant interactions (Chapter 2), poorly explored physiological processes such as nutrient resorption (Chapter 4) and the importance of stoichiometry studies for describing changes at ecosystem level and predicting future scenarios (Chapter 3). These studies add new knowledge to the ecological stoichiometry field and highlights the importance of this approach in the ecological studies.
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Imeh-Nathaniel, Adebobola. "Evolutionary Ecology of Arabidopsis thaliana: Interactions with Biotic and Abiotic Environmental Factors." Bowling Green State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1351039606.
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Barron, Harley. "Infection of Paulownia by Alternaria and influence of abiotic and biotic factors." Thesis, Barron, Harley (2003) Infection of Paulownia by Alternaria and influence of abiotic and biotic factors. Honours thesis, Murdoch University, 2003. https://researchrepository.murdoch.edu.au/id/eprint/32748/.
Full textAbstract:
Paulownia is a newly developed industry in Western Australia. Relying on high levels of fertiliser and irrigation to attain maximum growth, Paulownia often has nitrogen levels of 4.5 to 5 %. Alternaria, a pathogen with the potential to defoliate trees, has been isolated from blighted leaves of Paulownia for the first time in the literature. It was hypothesised that luxury fertiliser treatments may predispose Paulownia fortunei to disease.
To test for the influence of luxury fertiliser regimes on Alternaria blight of Paulownia fortunei, clonal trees were grown in a glasshouse and fertilised using a nil, low, medium and high fertiliser regime. Plants were measured
for height, stem diameter, gas exchange, chlorophyll, soluble protein and inorganic nutrient concentrations in the leaves.
It was found that rising fertiliser supply resulted in all measures increasing, then plateauing at the two highest fertiliser rates. The only exceptions to this trend were leaf sodium and stem boron and potassium concentrations which dropped with increasing fertiliser. Photosynthesis
and leaf nitrate were the only measures which were significantly higher in the highest fertiliser treatment. Thus, concluding that additional N, up to 46%, is of limited benefit to plant growth and function.
Three inoculation treatments were conducted, leaf disc, excised leaf and in-situ. Each infection trial only produced lesions where leaves were wounded prior to infection. Fertiliser treatments had no effect on disease
development in the leaf disc and excised leaf inoculation treatments. However, the in-situ inoculation trial had significantly (p < 0.01) larger lesions in the nil fertiliser treatment than all other fertiliser treatments.
Unfortunately, there was no significant difference between the inoculated and control leaves within the nil fertiliser treatment.
A systemic fungicidal influence on Paulownia by VAM was also examined. Seedlings inoculated with VAM were measured by the same methods as the nutrition trial with the exception of gas exchange. The presence of VAM increased plant height, root weight and approximately half of the
nutrients analysed. Fertiliser treatment significantly increased the majority of plant biomass and function measurements. However, the inorganic nutrient analysis of the leaves revealed that the soil sterilisation process
resulted in more nutrients becoming available to the plants.
The infection of the VAM trial with Alternaria resulted in no lesions on the leaves and stems.
There is no evidence to suggest that the luxurious fertiliser applied to field grown Paulownia predisposes them to infection by Alternaria. However, there is evidence that this pathogen may be opportunistic as only wounded leaves produced lesions during all nutrient infection trials. The impact of VAM on Paulownia growth is limited and needs further research.
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Ersoy, Zeynep. "Biotic and environmental factors shaping body size distributions in freshwater planktonic food webs." Doctoral thesis, Universitat de Vic - Universitat Central de Catalunya, 2018. http://hdl.handle.net/10803/665387.
Full textAbstract:
Les interaccions basades en la mida individual dels organismes tenen un paper important en la dinàmica de la comunitat i en els processos dels ecosistemes aquàtics, ja que la mida d’un individu és un tret clau dels organismes molt vinculat a la seva taxa metabòlica. El canvi climàtic i les pertorbacions afecten a les xarxes tròfiques planctòniques d'aigua dolça, debilitant les interaccions basades en la mida dels individus.
En aquesta tesi es van desenvolupar quatre estudis relacionats però independents per obtenir una comprensió més profunda de les interaccions tròfiques basades en la mida individual dels organismes. L’objectiu era demostrar com els factors biòtics i ambientals afecten les interaccions basades en la mida dels individus de xarxes tròfiques planctòniques utilitzant aproximacions observacionals i experimentals en diferents localitats a Europa.
Generalitzant, les nostres troballes clau d'aquesta tesi ressalten la importància d’integrar les relacions basades en la mida dels organismes i la resiliència de les comunitats amb la variació intraespecífica dels organismes a l’hora d’estudiar les interaccions tròfiques entre els organismes d’un ecosistema aquàtic. La comprensió d'aquestes interaccions ens permetrà gestionar i restaurar millor els ecosistemes aquàtics davant el canvi climàtic i altres pertorbacions induïdes per l'home.<br>Individual size-based interactions play a significant role in the community dynamics and ecosystem processes of aquatic ecosystems, because body size is a key trait of organisms that is highly linked to metabolic rates. Climate change and disturbances influence freshwater planktonic food webs, weakening the strength of size-based interactions.
In this thesis, we conducted four related but independent studies to obtain a deeper understanding of the size-based trophic interactions. We aimed to demonstrate biotic and environmental factors influencing size-based interactions in planktonic food webs using observational and experimental approaches at different locations in Europe. Overall, our key findings from this thesis suggest that integrating size-based relationships and resilience of communities together with intraspecific variation is important while studying trophic interactions. Understanding these interactions will allow us to better manage and restore aquatic ecosystems in the face of climate change and other human-induced disturbances.
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Gworek, Jennifer R. "Interacting abiotic and biotic factors affecting Jeffrey pine regeneration along an elevational gradient." abstract and full text PDF (free order & download UNR users only), 2005. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1433401.
Full textBooks on the topic "Biotic factors"
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Singh, Ashutosh, Saurabh Pandey, and Amarjeet Kumar. Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704.
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Wani, Shabir Hussain, Vennampally Nataraj, and Gyanendra Pratap Singh, eds. Transcription Factors for Biotic Stress Tolerance in Plants. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-12990-2.
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Salomon, Anne K. Investigating the relative roles of natural factors and shoreline harvest in altering the community structure, dynamics and diversity of the Kenai Peninsula's rocky intertidal. Exxon Valdez Oil Spill Trustee Council, 2006.
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Strong, W. L. Ecoclimatic regions of Canada : first approximation. Sustainable Development Branch, Canadian Wildlife Service, 1989.
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R, Allenby Braden, Richards Deanna J, and National Academy of Engineering, eds. The greening of industrial ecosystems. National Academy Press, 1994.
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Ismailov, Nariman. Globalism and ecophilosophy of the future. INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1212905.
Full textAbstract:
From the point of view of the new science of globalism, the problems of the ecological, socio-economic state of the world and countries are considered through the prism of the interaction of the human psyche and society and the inhabited world. The criteria of ecological civilization of countries and peoples are justified. Optimizing the consumption of natural bio-and energy resources is becoming a fundamental environmental factor for sustainable development. The "Law of the maximum for humanity" as the law of the biosphere can be the arbitration court, the neutral force that will explain the historical need for mutual understanding, taking into account the interests of ecology and economy for the survival of man as a biovid on Earth; a new reality will begin to form — the phenomenon of co-residence of the world society with the biosphere. The world's population, its energy and bio-consumption, as well as all living matter on the planet, must correspond to the biological capacity of the Earth and not go beyond its boundaries. The task of the society is to implement a worldview breakthrough at the current stage of development, its own cultural mutation, which in the future will create the basis for adaptive technological and socio-cultural development. The task is to classify the entire Earth as a "Green Book" and to solve systemic environmental problems of a global nature. An integral part of sustainable development should be the principle of "vital consumption" at both the personal and social level, instead of the dominant principle of"expanded production and consumption". The indicator of the" culture of consumption "of natural resources, both at the individual level and at the level of society, should be included as an integral part of the integral indicator in the "True Indicator of Progress" and the "Human Development Index".
 The book is interdisciplinary in nature; it is a kind of scientific and philosophical poetic essay intended for teachers and students of universities in the field of sociology, ecology, biology and related fields, as well as for everyone who cares about the future of society.
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Nataraj, Vennampally. Transcription Factors for Biotic Stress Tolerance in Plants. Springer International Publishing AG, 2023.
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Vennampally, Nataraj, Shabir Hussain Wani, and Gyanendra Pratap Singh. Transcription Factors for Biotic Stress Tolerance in Plants. Springer International Publishing AG, 2022.
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Orcutt, David M., and Erik T. Nilsen. Physiology of Plants under Stress: Soil and Biotic Factors. Wiley & Sons, Incorporated, John, 2008.
Find full textBook chapters on the topic "Biotic factors"
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Chithra, M., S. Senthilkumar, R. S. Afiya, and S. Manivannan. "Molecular Mechanism of Melatonin Interaction on Biotic Stress Tolerance in Horticulture Crops." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-9.
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Majhi, Prasanta Kumar, Tanmaya Kumar Bhoi, Ipsita Samal, et al. "The Exploitation of Next-Generation Breeding Strategies to Build Biotic Stress Resilience in Crops." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-11.
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Nagalakshmi, R. M., R. Sangeetha Vishnu Prabha, K. Shamini, and R. Ponmani. "Recent Advances on the Impact of Climate Change on Host Plant Resistance and Its Molecular Mechanisms." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-7.
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Ray, Swati. "DNA Helicase: The Futuristic Instrument to Increase Biotic Crop Stress Tolerance." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-15.
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Kuniyal, Kanupriya, and Niki Nautiyal. "Molecular Mechanism of Host-Pathogen Interaction in Crop Plants." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-4.
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Agarwal, Priyanka, Ajay Kumar Chandra, Alka Bharati, Radheshyam Kumawat, Pramod Kumar Pandey, and Amarjeet Kumar. "Applications and Recent Advances in CRISPR-Cas Editing for Biotic Stress Management in Cereals." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-12.
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Chandra, Ajay Kumar, Priyanka Agarwal, Alka Bharati, Radheshyam Kumawat, Pramod Kumar Pandey, and Amarjeet Kumar. "Resilient Agriculture in Cereal Crops and Its Tolerance Mechanism." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-16.
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Dinkar, Vishal, Jagmohan Singh, Charishma Krishnappa, et al. "Insights into the Molecular Mechanism of Plant-Pathogen Interactions in Fungal Diseases of Crop Plants." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-5.
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Afiya, R. S., S. Senthilkumar, M. Chithra, and S. Manivannan. "Recent Advances in CRISPR-Cas for Biotic Stress Management in Fruits." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-13.
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Ramkumar, Manisha Chaudhary, Prince Sahu, et al. "Effect of Humidity on Pest and Disease Incidence in Crops." In Climate Change and Biotic Factors. Apple Academic Press, 2025. https://doi.org/10.1201/9781003568704-2.
Full textConference papers on the topic "Biotic factors"
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Kearns, J. R., C. R. Clayton, G. P. Halada, J. B. Gillow, and A. J. Francis. "The Application of XPS to the Study of MIC." In CORROSION 1992. NACE International, 1992. https://doi.org/10.5006/c1992-92178.
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Abstract The biotic and abiotic factors that contribute to Microbiologically Influenced Corrosion (MIC) involve the transformation of chemical species at a metal surface. X-ray Photoelectron Spectroscopy (XPS) is utilized in conjunction with conventional microbiological and Quantitative Chemical Analytical techniques to better understand the effect of environmental conditions on microbial behavior as well as the ability of bacteria to alter local environmental conditions. Specifically, the interaction of Fe, Cr, Ni, Mo ions with Desulfovibrio sp. under anoxic conditions were studied. This is the first phase of a systematic study of microbial activity and the effects of alloy elements and thermo-mechanical treatments on the MIC resistance of stainless steels.
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Yu, Xueping, and Takeshi Hayakawa. "Investigation of influence factors of embedded droplet printing for generation of cancer cell spheroids with controllable size*." In 2024 IEEE International Conference on Cyborg and Bionic Systems (CBS). IEEE, 2024. https://doi.org/10.1109/cbs61689.2024.10860319.
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Chen, hongyu. "Effect factors study of ultrasonic nondestructive testing of residual stress." In 4th International Conference on Automation Control. Algorithm and Intelligent Bionics, edited by Jing Na and Shuping He. SPIE, 2024. http://dx.doi.org/10.1117/12.3040236.
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Brossia, C. Sean, and Lietai Yang. "Studies of Microbiologically Influenced Corrosion Using a Coupled Multielectrode Array Sensor." In CORROSION 2003. NACE International, 2003. https://doi.org/10.5006/c2003-03575.
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Abstract A newly developed multielectrode array sensor (MASS) was used to conduct a series of abiotic and biotic tests to determine if the probe can detect corrosion induced by microbial activity. The probe was able to determine the maximum corrosion rate in the presence of sulfate reducing bacteria (SRB) and showed that this rate was at least a factor of 10 greater than in the absence of SRBs. In addition, the corrosion rates obtained using the probe were much higher than those determined using linear polarization resistance further demonstrating its inherent better sensitivity to localized corrosion.
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Horn, Joanne M., Angel Rivera, Tiangan Lian, and Denny A. Jones. "MIC Evaluation and Testing for the Yucca Mountain Repository." In CORROSION 1998. NACE International, 1998. https://doi.org/10.5006/c1998-98152.
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Abstract Assessment of candidate waste package materials for nuclear waste disposal requires determination of any microbiological contribution to overall corrosion. Two systems employing characterized bacterial isolates from the Yucca Mountain site were designed to assess the rates of MIC on carbon steel C1020 and Alloy 400 in simulated groundwater. Microbial activities increased rates of carbon steel corrosion by a factor of 5-6-fold compared to abiotic corrosion rates on the same material. Rates of biocorrosion of Alloy 400 was 7-8-fold lower than that of C1020. Cathodic reactions were equivalent between biotic and abiotic systems on C1020, while the anodic reaction was activated on inoculated C1020 coupons. Further, while passivity was observed on sterile carbon steel, no such effect was demonstrated on inoculated samples. Novel corrosion cell designs were successful in obtaining rates of MIC on more corrosion-resistant candidate alloys.
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Washington, Peter, Karina G. Samuel-Gama, Shirish Goyal, Ashwin Ramaswami, and Ingmar H. Riedel-Kruse. "Prototyping Biotic Games and Interactive Experiments with JavaScript." In CHI '18: CHI Conference on Human Factors in Computing Systems. ACM, 2018. http://dx.doi.org/10.1145/3170427.3186510.
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Maramokhin, E. V., M. V. Sirotina, and A. S. Dyukova. "THE ROLE OF SUBSTRATE FACTOR IN DISTRIBUTION OF CERTAIN XYLOTROPHIC BASIDIOMYCETES IN BIRCH AND ASPEN FORESTS OF KOSTROMA REGION." In SAKHAROV READINGS 2021: ENVIRONMENTAL PROBLEMS OF THE XXI CENTURY. International Sakharov Environmental Institute, 2021. http://dx.doi.org/10.46646/sakh-2021-1-290-294.
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The distribution of xylotrophic basidiomycetes, as any other species, depends on ecological elasticity in relation to abiotic, biotic and anthropogenic environmental factors. A special role among biotic factors for these organisms is assigned to substrate specialization. The high significance of the substrate factor is distinctive for the destructor fungi, which is reflected in the special enzymatic apparatus of these organisms capable of destroying lignin and cellulose. This article comprehensively examines the impact of the substrate factor on the distribution of the studied phytopathogens in small-leaved forests of Kostroma region.This will make it possible to better understand the biology and ecology of xylotrophic basidiomycetes.
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Maramokhin, E. V., M. V. Sirotina, and A. S. Dyukova. "THE ROLE OF SUBSTRATE FACTOR IN DISTRIBUTION OF CERTAIN XYLOTROPHIC BASIDIOMYCETES IN BIRCH AND ASPEN FORESTS OF KOSTROMA REGION." In SAKHAROV READINGS 2021: ENVIRONMENTAL PROBLEMS OF THE XXI CENTURY. International Sakharov Environmental Institute, 2021. http://dx.doi.org/10.46646/sakh-2021-1-290-294.
Full textAbstract:
The distribution of xylotrophic basidiomycetes, as any other species, depends on ecological elasticity in relation to abiotic, biotic and anthropogenic environmental factors. A special role among biotic factors for these organisms is assigned to substrate specialization. The high significance of the substrate factor is distinctive for the destructor fungi, which is reflected in the special enzymatic apparatus of these organisms capable of destroying lignin and cellulose. This article comprehensively examines the impact of the substrate factor on the distribution of the studied phytopathogens in small-leaved forests of Kostroma region.This will make it possible to better understand the biology and ecology of xylotrophic basidiomycetes.
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Litvinova, V., and Natal'ya Kozulina. "THE INFLUENCE OF BIOTIC AND ABIOTIC FACTORS ON SOIL FERTILITY." In «PROBLEMS OF SOIL FERTILITY IN MODERN AGRICULTURE». Krasnoyarsk Scientific Research Institute of Agriculture is a separate division of the Federal Research Center KSC SB RAS, 2024. http://dx.doi.org/10.52686/9785605087878_368.
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The article considers biotic and abiotic factors affecting the soil. The features of the climatic conditions of the steppes and methods of soil restoration in steppe erosion-hazardous areas of Siberia are presented. Recommendations for soil protection and improvement of soil fertility in Mongolia are proposed.
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Suryani, Lilis, Henny Pramoedyo, Sri Andarini, and Sudarto. "The biotic environmental as risk factors human leptospirosis in Yogyakarta, Indonesia." In TOWARDS THE SUSTAINABLE USE OF BIODIVERSITY IN A CHANGING ENVIRONMENT: FROM BASIC TO APPLIED RESEARCH: Proceeding of the 4th International Conference on Biological Science. Author(s), 2016. http://dx.doi.org/10.1063/1.4953509.
Full textReports on the topic "Biotic factors"
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Daniel P. Molloy. EVALUATION OF BIOTIC AND TREATMENT FACTORS RELATING TO BACTERIAL CONTROL OF ZEBRA MUSSELS. Office of Scientific and Technical Information (OSTI), 2002. http://dx.doi.org/10.2172/811387.
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Harms, Nathan, Judy Shearer, James Cronin, and John Gaskin. Geographic and genetic variation in susceptibility of Butomus umbellatus to foliar fungal pathogens. Engineer Research and Development Center (U.S.), 2021. http://dx.doi.org/10.21079/11681/41662.
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Large-scale patterns of plant invasions may reflect regional heterogeneity in biotic and abiotic factors and genetic variation within and between invading populations. Having information on how effects of biotic resistance vary spatially can be especially important when implementing biological control because introduced agents may have different Impacts through interactions with host-plant genotype, local environment, or other novel enemies. We conducted a series of field surveys and laboratory studies to determine whether there was evidence of biotic resistance, as foliar fungal pathogens, in two introduced genotypes (triploid G1, diploid G4) of the Eurasian wetland weed, Butomus umbellatus L. in the USA. We tested whether genotypes differed in disease attack and whether spatial patterns in disease incidence were related to geographic location or climate for either genotype. After accounting for location (latitude, climate), G1 plants had lower disease incidence than G4 plants in the field (38% vs. 70%) but similar pathogen richness. In contrast, bioassays revealed G1 plants consistently received a higher damage score and had larger leaf lesions regardless of pathogen. These results demonstrate that two widespread B. umbellatus genotypes exhibit different susceptibility to pathogens and effectiveness of pathogen biological controls may depend on local conditions.
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Lindsay, Denise, Xin Guan, John Mylroie, and Richard Lance. Detection and decay of different classes of environmental RNA (eRNA) from zebrafish (Danio rerio). Engineer Research and Development Center (U.S.), 2024. http://dx.doi.org/10.21079/11681/48780.
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This technical note contributes to the growing body of knowledge about macroscopic eukaryotic environmental RNA (eRNA) by exploring detection and decay for several different zebrafish (Danio rerio) eRNAs in a mesocosm setting. The study addressed four basic hypotheses: (1) D. rerio would deposit detectable levels of eRNA into water, (2) different classes of eRNA would be detected, (3) different eRNA sequences (for example, loci) would degrade at different rates, and (4) abiotic and biotic factors would influence rates of degradation. For the last hypothesis, we tracked eRNA concentration decay under treatments with different water temperatures and levels of microbiological activity, two factors known to significantly influence environmental DNA (eDNA) decay (Barnes et al. 2014; Lance et al. 2017; Nielsen et al. 2007; Strickler et al. 2015).
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Bonneau, L., N. Hitt, K. Jayachandran, and M. Marchetti. Freshwater Ecosystems and Biodiversity. American Museum of Natural History, 2010. http://dx.doi.org/10.5531/cbc.ncep.0105.
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Freshwater ecosystems are important for many reasons, including their ecosystem services to humans. However, this module invites students to think critically about the ecological structure, function, and distribution of freshwater systems. Freshwater ecosystems are driven by physical habitat, energy sources, water quality biotic interactions, hydrology, and connectivity. Variations in these factors result in significantly different environments, including upland streams and rivers, large lakes, floodplain rivers and wetlands, and xeric freshwaters. In the exercise, student groups will generate hypotheses about how freshwater habitats support biodiversity (richness and endemism). Students will then collect data from the Freshwater Ecoregions of the World (FEOW) database to test their hypotheses and answer a set of related questions.
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DeSaix, Matthew. Bird community monitoring at New River Gorge National River, Gauley River National Recreation Area, and Bluestone National Scenic River, 1997 - 2018. National Park Service, 2022. http://dx.doi.org/10.36967/nrr-2289846.
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Birds are prominent features of National Park Service lands and are effective indicators for monitoring ecosystem health. Assessing the temporal change of avian species abundance depends on long-term monitoring of bird communities and trends, however long-term monitoring programs are generally uncommon. In this report, we summarize 22 years (1997-2018) of point count data across five sites on West Virginia National Park Service lands (three in New River Gorge National River, one in Gauley River National Recreation Area, and one in Bluestone National Scenic River) and compare these results to our analysis of Breeding Bird Survey data for the same time period across all of West Virginia. The objectives of this analysis are two-fold: 1) describe the biotic integrity of the National Park Service lands in West Virginia and 2) Quantify trends in guilds and species abundance. During the 20-year period of this survey, 85 breeding resident species were detected. The West Virginia National Park Service lands are home to stable populations of Wood Thrush and Yellow-billed Cuckoo, both species of continental concern by Partners in Flight. Seven species have declined precipitously on NPS lands during this time period. Three of these species are also experiencing declines across the rest of West Virginia (Blue-gray Gnatcatcher, Carolina Chickadee, Kentucky Warbler), but the other 4 species are stable across West Virginia (Acadian Flycatcher, Black-throated Green Warbler, Northern Parula, Swainson’s Warbler). Four species that are declining across West Virginia (Great Crested Flycatcher, Indigo Bunting, Red-eyed Vireo, and Worm-eating Warbler) are stable on southern West Virginia NPS lands. Additionally, the upper-canopy foraging guild of species has decreased significantly on NPS lands in southern West Virginia. An analysis of community biotic integrity revealed that the southern West Virginia NPS lands have been stable at a rating of high biotic integrity every year for the duration of this survey. Future research should delve into the underlying factors that may be driving the trends in abundance at different scales.
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Tsybekmitova, G. Ts, L. D. Radnaeva, N. A. Tashlykova, et al. THE EFFECT OF CLIMATIC SHIFTS ON BIODIVERSITY OF PHYTOCENOSIS: LAKE ARAKHLEY (EASTERN SIBERIA, RUSSIA). DOICODE, 2020. http://dx.doi.org/10.18411/0973-7308-2020-35-3-77-90.
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Lake Arakhley is located within the Lake Baikal basin in Eastern Siberia, Russia. The area is characterized by continental subarctic climate with considerate diurnal temperature range, long cold dry winters and short hot summers with more precipitation occurring during the latter half of the summer. Climatic shifts in high water years and low water years result in morphometric changes in the lake and in the chemical and physical parameters of the ecosystem. During low water years, concentrations of ammonium nitrogen and nitrite nitrogen are decreased, whereas nitrate concentration increases. High water years feature average concentrations of ammonium ions 1.5–2 times higher than the values of recent dry years. Redundancy analysis (RDA) of abiotic factors and biotic community indicated that the community structure shows the greatest correlation with physical and chemical parameters of water and biogenic elements (nitrites, ammonium, phosphates) along the first axis, and with the lake depth and transparency along the second axis. Changes in abiotic factors induce functioning and formation of characteristic communities of the primary producers in the trophic structure of the ecosystem. During low water years, with increased level of autochthonous organic matter, Lindavia comta dominance is observed, while during high water years, with increased allochthonous organic matter Asterionella formosa appeared as dominant. Currently, during low water years, the hydrophytes community is monodominant and composed of Ceratophyllum demersum. Meanwhile, such species indicating eutrophic conditions as Myriophyllum sibiricum, Potamogeton pectinatus are found in the lake vegetation.
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McFarland, Victor A., Charles H. Lutz, and Francis J. Reilly. Factors Influencing Bioaccumulation of Sediment-Associated Contaminants by Aquatic Organisms: Factors Related to Biota. Environmental Effects of Dredging. Defense Technical Information Center, 1989. http://dx.doi.org/10.21236/ada292547.
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Venäläinen, Ari, Sanna Luhtala, Mikko Laapas, et al. Sää- ja ilmastotiedot sekä uudet palvelut auttavat metsäbiotaloutta sopeutumaan ilmastonmuutokseen. Finnish Meteorological Institute, 2021. http://dx.doi.org/10.35614/isbn.9789523361317.
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Climate change will increase weather induced risks to forests, and thus effective adaptation measures are needed. In Säätyö project funded by the Ministry of Agriculture and Forestry, we have summarized the data that facilitate adaptation measures, developed weather and climate services that benefit forestry, and mapped what kind of new weather and climate services are needed in forestry. In addition, we have recorded key further development needs to promote adaptation. The Säätyö project developed a service product describing the harvesting conditions of trees based on the soil moisture assessment. The output includes an analysis of the current situation and a 10-day forecast. In the project we also tested the usefulness of long forecasts beyond three months. The weather forecasting service is sidelined and supplemented by another co-operation project between the Finnish Meteorological Institute and Metsäteho called HarvesterSeasons (https://harvesterseasons.com/). The HarvesterSeasons service utilizes long-term forecasts of up to 6 months to assess terrain bearing conditions. A test version of a wind damage risk tool was developed in cooperation with the Department of Forest Sciences of the University of Eastern Finland and the Finnish Meteorological Institute. It can be used to calculate the wind speeds required in a forest area for wind damage (falling trees). It is currently only suitable for researcher use. In the Säätyö project the possibility of locating the most severe wind damage areas immediately after a storm was also tested. The method is based on the spatial interpolation of wind observations. The method was used to analyze storms that caused forest damages in the summer and fall of 2020. The produced maps were considered illustrative and useful to those responsible for compiling the situational picture. The accumulation of snow on tree branches, can be modeled using weather data such as rainfall, temperature, air humidity, and wind speed. In the Säätyö project, the snow damage risk assessment model was further developed in such a way that, in addition to the accumulated snow load amount, the characteristics of the stand and the variations in terrain height were also taken into account. According to the verification performed, the importance of abiotic factors increased under extreme snow load conditions (winter 2017-2018). In ordinary winters, the importance of biotic factors was emphasized. According to the comparison, the actual snow damage could be explained well with the tested model. In the interviews and workshop, the uses of information products, their benefits, the conditions for their introduction and development opportunities were mapped. According to the results, diverse uses and benefits of information products and services were seen. Information products would make it possible to develop proactive forest management, which would reduce the economic costs caused by wind and snow damages. A more up-to-date understanding of harvesting conditions, enabled by information products, would enhance the implementation of harvesting and harvesting operations and the management of timber stocks, as well as reduce terrain, trunk and root damage. According to the study, the introduction of information is particularly affected by the availability of timeliness. Although the interviewees were not currently willing to pay for the information products developed in the project, the interviews highlighted several suggestions for the development of information products, which could make it possible to commercialize them.
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Fait, Aaron, Grant Cramer, and Avichai Perl. Towards improved grape nutrition and defense: The regulation of stilbene metabolism under drought. United States Department of Agriculture, 2014. http://dx.doi.org/10.32747/2014.7594398.bard.
Full textAbstract:
The goals of the present research proposal were to elucidate the physiological and molecular basis of the regulation of stilbene metabolism in grape, against the background of (i) grape metabolic network behavior in response to drought and of (ii) varietal diversity. The specific objectives included the study of the physiology of the response of different grape cultivars to continuous WD; the characterization of the differences and commonalities of gene network topology associated with WD in berry skin across varieties; the study of the metabolic response of developing berries to continuous WD with specific attention to the stilbene compounds; the integration analysis of the omics data generated; the study of isolated drought-associated stress factors on the regulation of stilbene biosynthesis in plantaand in vitro. Background to the topic Grape quality has a complex relationship with water input. Regulated water deficit (WD) is known to improve wine grapes by reducing the vine growth (without affecting fruit yield) and boosting sugar content (Keller et al. 2008). On the other hand, irregular rainfall during the summer can lead to drought-associated damage of fruit developmental process and alter fruit metabolism (Downey et al., 2006; Tarara et al., 2008; Chalmers et al., 792). In areas undergoing desertification, WD is associated with high temperatures. This WD/high temperature synergism can limit the areas of grape cultivation and can damage yields and fruit quality. Grapes and wine are the major source of stilbenes in human nutrition, and multiple stilbene-derived compounds, including isomers, polymers and glycosylated forms, have also been characterized in grapes (Jeandet et al., 2002; Halls and Yu, 2008). Heterologous expression of stilbenesynthase (STS) in a variety of plants has led to an enhanced resistance to pathogens, but in others the association has not been proven (Kobayashi et al., 2000; Soleas et al., 1995). Tomato transgenic plants harboring a grape STS had increased levels of resveratrol, ascorbate, and glutathione at the expense of the anthocyanin pathways (Giovinazzo et al. 2005), further emphasizing the intermingled relation among secondary metabolic pathways. Stilbenes are are induced in green and fleshy parts of the berries by biotic and abiotic elicitors (Chong et al., 2009). As is the case for other classes of secondary metabolites, the biosynthesis of stilbenes is not very well understood, but it is known to be under tight spatial and temporal control, which limits the availability of these compounds from plant sources. Only very few studies have attempted to analyze the effects of different environmental components on stilbene accumulation (Jeandet et al., 1995; Martinez-Ortega et al., 2000). Targeted analyses have generally shown higher levels of resveratrol in the grape skin (induced), in seeded varieties, in varieties of wine grapes, and in dark-skinned varieties (Gatto et al., 2008; summarized by Bavaresco et al., 2009). Yet, the effect of the grape variety and the rootstock on stilbene metabolism has not yet been thoroughly investigated (Bavaresco et al., 2009). The study identified a link between vine hydraulic behavior and physiology of stress with the leaf metabolism, which the PIs believe can eventually lead to the modifications identified in the developing berries that interested the polyphenol metabolism and its regulation during development and under stress. Implications are discussed below.
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Ginzberg, Idit, and Walter De Jong. Molecular genetic and anatomical characterization of potato tuber skin appearance. United States Department of Agriculture, 2008. http://dx.doi.org/10.32747/2008.7587733.bard.
Full textAbstract:
Potato (Solanum tuberosum L.) skin is composed of suberized phellem cells, the outer component of the tuber periderm. The focus of the proposed research was to apply genomic approaches to identify genes that control tuber skin appearance - smooth and shiny skin is highly preferred by the customers while russeted/netted skin potatoes are rejected. The breeding program (at Cornell University) seeks to develop smooth-skin varieties but has encountered frequent difficulties as inheritance of russeting involves complementary action by independently segregating genes, where a dominant allele at each locus is required for any degree of skin russeting. On the other hand, smooth-skin varieties frequently develop unsightly russeting in response to stress conditions, mainly high soil temperatures. Breeding programs in Israel aimed towards the improvement of heat tolerant varieties include skin quality as one of the desired characteristics. At the initiation of the present project it was unclear whether heat induced russeting and genetically inherited russeting share the same genes and biosynthesis pathways. Nevertheless, it has been suggested that russeting might result from increased periderm thickness, from strong cohesion between peridermal cells that prevents the outer layers from sloughing off, or from altered suberization processes in the skin. Hence, the original objectives were to conduct anatomical study of russet skin development, to isolate skin and russeting specific genes, to map the loci that determine the russet trait, and to compare with map locations the candidate russet specific genes, as well as to identify marker alleles that associated with russet loci. Anatomical studies suggested that russet may evolve from cracking at the outer layers of the skin, probably when skin development doesn’t meet the tuber expansion rate. Twodimensional gel electrophoresis and transcript profiling (cDNA chip, potato functional genomic project) indicated that in comparison to the parenchyma tissue, the skin is enriched with proteins/genes that are involved in the plant's responses to biotic and abiotic stresses and further expand the concept of the skin as a protective tissue containing an array of plantdefense components. The proteomes of skin from heat stressed tubers and native skin didn’t differ significantly, while transcript profiling indicated heat-related increase in three major functional groups: transcription factors, stress response and protein degradation. Exceptional was ACC synthase isogene with 4.6 fold increased level in the heat stressed skin. Russeting was mapped to two loci: rusB on chromosome 4 and rusC on chromosome 11; both required for russeting. No evidence was found for a third locus rusA that was previously proposed to be required for russeting. In an effort to find a link between the russeting character and the heat-induced russeting an attempt was made to map five genes that were found in the microarray experiment to be highly induced in the skin under heat stress in the segregating russet population. Only one gene was polymorphic; however it was localized to chromosome 2, so cannot correspond to rusB or rusC. Evaluation of AFLP markers tightly linked to rusB and rusC showed that these specific alleles are not associated with russeting in unrelated germplasm, and thus are not useful for MAS per se. To develop markers useful in applied breeding, it will be necessary to screen alleles of additional tightly linked loci, as well as to identify additional russet (heat-induced and/or native) related genes.