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Punctelia Punctata
''Punctelia'' is a genus of foliose lichens belonging to the large family Parmeliaceae. The genus, which contains about 50 species, was segregated from genus '' Parmelia'' in 1982. Characteristics that define ''Punctelia'' include the presence of hook-like to thread-like conidia (asexual spores), simple rhizines (root-like structures that attach the lichen thallus to its substrate), and point-like pseudocyphellae (tiny pores on the thallus surface that facilitate gas exchange). It is this last feature that is alluded to in the vernacular names speckled shield lichens or speckleback lichens. ''Punctelia'' lichens grow on bark, wood, and rocks. The genus is cosmopolitan, occurring on all continents but Antarctica. Species are found in temperate to subtropical locations. ''Punctelia'' has centres of distribution in the Neotropics and Africa; about half of the known species occur in South America. The photobiont partners of ''Punctelia'' are green algae in the genus ''Treb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hildur Krog
Hildur Krog (22 March 1922 – 25 August 2014) was a Norwegian botanist. She was born in Modum. She took the dr.philos. degree in 1968 with a thesis on Alaskan lichens, was hired as a curator at the Botanical Museum of Oslo in 1971 and served as professor at the University of Oslo from 1987 to 1992. For 15 year from 1969 she collaborated with the British amateur lichenologist Dougal Swinscow to study the macrolichen flora of East Africa. They undertook field collections as well as characterisation and revision of the limited existing lichen knowledge of the region, presented in 33 scientific publications and a book ''The Macrolichens of East Africa'', British Museum (Natural History) in 1988. In 1992 Hildur Krog was awarded the Acharius Medal by the International Association for Lichenology She was a fellow of the Norwegian Academy of Science and Letters. She died in 2014. Several lichen are named in her honour, including ''Krogia'' which a genus of corticolous lichens in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small and usually only have precipitation changes. In temperate climates, not only do latitudinal positions influence temperature changes, but sea currents, prevailing wind direction, continentality (how large a landmass is) and altitude also shape temperate climates. The Köppen climate classification defines a climate as "temperate" C, when the mean temperature is above but below in the coldest month to account for the persistency of frost. However, other climate classifications set the minimum at . Zones and climates The north temperate zone extends from the Tropic of Cancer (approximately 23.5° north latitude) to the Arctic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parmelia Borreri
''Punctelia borreri'' is a species of foliose lichen in the family Parmeliaceae. It is a common and widely distributed species, occurring in tropical, subtropical, and temperate regions of Africa, Asia, Europe, North America, Oceania, and South America. The lichen typically grows on bark of deciduous trees, and less commonly on rock. Some European countries have reported increases in the geographic range or regional frequency of the lichen in recent decades, attributed alternatively to a reduction of atmospheric sulphur dioxide levels or an increase in temperatures resulting from climate change. The lichen is characterised by a greenish-grey to bluish-grey upper thallus surface, a black lower surface, pseudocyphellae on the surface of the thallus (tiny pores that facilitate gas exchange), and chemically, by the presence of gyrophoric acid in the medulla. There are several lookalike ''Punctelia'' species, including '' P. subrudecta'', '' P. perreticulata'', and '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytogeography
Phytogeography (from Greek φυτόν, ''phytón'' = "plant" and γεωγραφία, ''geographía'' = "geography" meaning also distribution) or botanical geography is the branch of biogeography that is concerned with the geographic distribution of plant species and their influence on the earth's surface. Phytogeography is concerned with all aspects of plant distribution, from the controls on the distribution of individual species ranges (at both large and small scales, see species distribution) to the factors that govern the composition of entire communities and floras. Geobotany, by contrast, focuses on the geographic space's influence on plants. Fields Phytogeography is part of a more general science known as biogeography. Phytogeographers are concerned with patterns and process in plant distribution. Most of the major questions and kinds of approaches taken to answer such questions are held in common between phyto- and zoogeographers. Phytogeography in wider sense (or geobot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Metabolism
Secondary metabolism (also called specialized metabolism) is a term for pathways and small molecule products of metabolism that are involved in ecological interactions, but are not absolutely required for the survival of the organism. These molecules are sometimes produced by specialized cells, such as laticifers in plants. Secondary metabolites commonly mediate antagonistic interactions, such as competition and predation, as well as mutualistic ones such as pollination and resource mutualisms. Examples of secondary metabolites include antibiotics, pigments and scents. The opposite of secondary metabolites are primary metabolites, which are considered to be essential to the normal growth or development of an organism. Secondary metabolites are produced by many microbes, plants, fungi and animals, usually living in crowded habitats, where chemical defense represents a better option than physical escape. It is very hard to distinguish primary and secondary metabolites due to often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontogeny
Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the study of the entirety of an organism's lifespan. Ontogeny is the developmental history of an organism within its own lifetime, as distinct from phylogeny, which refers to the evolutionary history of a species. Another way to think of ontogeny is that it is the process of an organism going through all of the developmental stages over its lifetime. The developmental history includes all the developmental events that occur during the existence of an organism, beginning with the changes in the egg at the time of fertilization and events from the time of birth or hatching and afterward (i.e., growth, remolding of body shape, development of secondary sexual characteristics, etc.). While developmental (i.e., ontogenetic) processes can influence sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumscription (taxonomy)
In biological taxonomy, circumscription is the content of a taxon, that is, the delimitation of which subordinate taxa are parts of that taxon. If we determine that species X, Y, and Z belong in Genus A, and species T, U, V, and W belong in Genus B, those are our circumscriptions of those two genera. Another systematist might determine that T, U, V, W, X, Y, and Z all belong in genus A. Agreement on circumscriptions is not governed by the Codes of Zoological or Botanical Nomenclature, and must be reached by scientific consensus. A goal of biological taxonomy is to achieve a stable circumscription for every taxon. This goal conflicts, at times, with the goal of achieving a natural classification that reflects the evolutionary history of divergence of groups of organisms. Balancing these two goals is a work in progress, and the circumscriptions of many taxa that had been regarded as stable for decades are in upheaval in the light of rapid developments in molecular phylogenetics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Pollution
Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types of air pollutants, such as gases (including ammonia, carbon monoxide, sulfur dioxide, nitrous oxides, methane, carbon dioxide and chlorofluorocarbons), particulates (both organic and inorganic), and biological molecules. Air pollution can cause diseases, allergies, and even death to humans; it can also cause harm to other living organisms such as animals and food crops, and may damage the natural environment (for example, climate change, ozone depletion or habitat degradation) or built environment (for example, acid rain). Air pollution can be caused by both human activities and natural phenomena. Air pollution is a significant risk factor for a number of pollution-related diseases, including respiratory infections, heart disease, COPD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioindicator
A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other small water crustaceans that are present in many water bodies can be monitored for changes (biochemical, physiological, or behavioural) that may indicate a problem within their ecosystem. Bioindicators can tell us about the cumulative effects of different pollutants in the ecosystem and about how long a problem may have been present, which physical and chemical testing cannot. A biological monitor or biomonitor is an organism that provides quantitative information on the quality of the environment around it. Therefore, a good biomonitor will indicate the presence of the pollutant and can also be used in an attempt to provide additional information about the amount and intensity of the exposure. A biological indicator is also the name given ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trebouxia
''Trebouxia'' is a unicellular green alga.Silverside, A. J. (2009). Retrieved from http://www.bioref.lastdragon.org/Chlorophyta/''Trebouxia''.html It is a photosynthetic organism that can exist in almost all habitats found in polar, tropical, and temperate regions.Erokhina, L. G., Shatilovich, A. V., Kaminskaya, O. P., & Gilichinskii, D. A. (2004). Spectral Properties of the Green Alga ''Trebouxia'', a Phycobiont of Cryptoendolithic Lichens in the Antarctic Dry Valley. Microbiology,73(4), 420-424. doi:10.1023/b:mici.0000036987.18559Lukesova, A., & Frouz, J. (2007). Soil and Freshwater Micro-Algae as a Food Source for Invertebrates in Extreme Environments. Cellular Origin, Life in Extreme Habitats and Astrobiology Algae and Cyanobacteria in Extreme Environments,265-284. doi:10.1007/978-1-4020-6112-7_14Seckbach, J. (2007). Algae and cyanobacteria in extreme environments. Dordrecht: Springer. doi:https://doi.org/10.1007/978-1-4020-6112-7Seckbach, J. (2002). Symbiosis: Mechanisms and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Algae
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to properly include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae. Many species live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds. A few other organi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photobiont
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( |
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