| Rhizocarpon superficiale | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Rhizocarpales |
| Family: | Rhizocarpaceae |
| Genus: | Rhizocarpon |
| Species: | R. superficiale |
| Binomial name | |
| Rhizocarpon superficiale | |
| Synonyms [1] | |
List
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Rhizocarpon superficiale is a species of saxicolous (rock-dwelling), crustose lichen in the family Rhizocarpaceae. [2] It occurs in Europe and North America.
The lichen was first scientifically described by the Swiss lichenologist Ludwig Schaerer in 1828. He initially classified it in the genus Lecidea . [3] Gustaf Oskar Andersson Malme transferred it to the genus Rhizocarpon in 1914. [4]
Rhizocarpon superficiale predominantly grows on rock surfaces, particularly in harsh environments like arctic and alpine regions, although it can occasionally be found in more temperate zones. This lichen is particularly adept at colonising exposed and windy ridge crests where snow cover is often minimal during the winter. It is commonly found on the summits above the treeline, which varies from about 1900 to 2000 metres in elevation depending on exposure. [5]
The species is extensively documented on reddish slabs of Precambrian argillite in southwestern Alberta, Canada. These locations are known for their accessibility even in midwinter and for the flatness of the rock, which is ideal for scientific study. Rhizocarpon superficiale forms populations on Table Mountain and Prairie Bluff, thriving in conditions where wind exposure maximises sun and air exposure, reducing snow cover and enhancing its survival and growth. [5]
Ecologically, Rhizocarpon superficiale inhabits a niche that allows it to experience a microclimate significantly warmer than the ambient air due to its proximity to the ground. This boundary-layer environment moderates extreme temperatures that might otherwise be detrimental to the lichen. The lichen's ability to endure and adapt to rapid temperature changes and hydration levels is critical for its survival in these alpine conditions. During chinook wind events, for instance, the lichen experiences swift transitions from heavy snowfall to melting conditions, leading to brief but significant periods of hydration essential for photosynthesis and carbon gain throughout the year. [5]
This lichen's ecological success is further evidenced by its ability to remain hydrated across all seasons, a rarity in alpine environments where low temperatures typically prevail. The periods of hydration, crucial for the lichen's metabolic processes, occur during varied weather patterns, including the unpredictable chinook winds which dramatically alter the microclimate. [5]
A microclimate is a local set of atmospheric conditions that differ from those in the surrounding areas, often slightly but sometimes substantially. The term may refer to areas as small as a few square meters or smaller or as large as many square kilometers. Because climate is statistical, which implies spatial and temporal variation of the mean values of the describing parameters, microclimates are identified as statistically distinct conditions which occur and/or persist within a region. Microclimates can be found in most places but are most pronounced in topographically dynamic zones such as mountainous areas, islands, and coastal areas.
Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets lower until it reaches sea level, and alpine tundra merges with polar tundra.
The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions. The tree line is sometimes distinguished from a lower timberline, which is the line below which trees form a forest with a closed canopy.
In archaeology, palaeontology, and geomorphology, lichenometry is a geomorphic method of geochronologic dating that uses lichen growth to determine the age of exposed rock, based on a presumed specific rate of increase in radial size over time. Measuring the diameter of the largest lichen of a species on a rock surface can therefore be used to determine the length of time the rock has been exposed. Lichen can be preserved on old rock faces for up to 10,000 years, providing the maximum age limit of the technique, but it is most accurate when applied to surfaces that have been exposed for less than 1,000 years.
Alpine plants are plants that grow in an alpine climate, which occurs at high elevation and above the tree line. There are many different plant species and taxa that grow as a plant community in these alpine tundra. These include perennial grasses, sedges, forbs, cushion plants, mosses, and lichens. Alpine plants are adapted to the harsh conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation, wind, drought, poor nutritional soil, and a short growing season.
Polar ecology is the relationship between plants and animals in a polar environment. Polar environments are in the Arctic and Antarctic regions. Arctic regions are in the Northern Hemisphere, and it contains land and the islands that surrounds it. Antarctica is in the Southern Hemisphere and it also contains the land mass, surrounding islands and the ocean. Polar regions also contain the subantarctic and subarctic zone which separate the polar regions from the temperate regions. Antarctica and the Arctic lie in the polar circles. The polar circles are imaginary lines shown on maps to be the areas that receives less sunlight due to less radiation. These areas either receive sunlight or shade 24 hours a day because of the earth's tilt. Plants and animals in the polar regions are able to withstand living in harsh weather conditions but are facing environmental threats that limit their survival.
Xerosere is a plant succession that is limited by water availability. It includes the different stages in a xerarch succession. Xerarch succession of ecological communities originated in extremely dry situation such as sand deserts, sand dunes, salt deserts, rock deserts etc. A xerosere may include lithoseres and psammoseres.
Rhizocarpon geographicum is a species of lichen, which grows on rocks in mountainous areas of low air pollution. Each lichen is a flat patch bordered by a black line of fungal hyphae. These patches grow adjacent to each other, leading to the appearance of a map or a patchwork field.
About 1,702 species of plants live on the Arctic tundra, including flowering plants, short shrubs, herbs, grasses, and mosses. These plants are adapted to short, cold growing seasons. They have the ability to withstand extremely cold temperatures in the winter, and grow and reproduce in summer conditions that are quite limiting.
Desiccation tolerance refers to the ability of an organism to withstand or endure extreme dryness, or drought-like conditions. Plants and animals living in arid or periodically arid environments such as temporary streams or ponds may face the challenge of desiccation, therefore physiological or behavioral adaptations to withstand these periods are necessary to ensure survival. In particular, insects occupy a wide range of ecologically diverse niches and, so, exhibit a variety of strategies to avoid desiccation.
The Ecology of the North Cascades is heavily influenced by the high elevation and rain shadow effects of the mountain range. The North Cascades is a section of the Cascade Range from the South Fork of the Snoqualmie River in Washington, United States, to the confluence of the Thompson and Fraser Rivers in British Columbia, Canada, where the range is officially called the Cascade Mountains but is usually referred to as the Canadian Cascades. The North Cascades Ecoregion is a Level III ecoregion in the Commission for Environmental Cooperation's classification system.
Rhizocarpon is a genus of crustose, saxicolous, lecideoid lichens in the family Rhizocarpaceae. The genus is common in arctic-alpine environments, but also occurs throughout temperate, subtropical, and even tropical regions. They are commonly known as map lichens because of the prothallus forming border-like bands between colonies in some species, like the common map lichen.
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial factor in shaping plant community, biodiversity, metabolic processes and ecosystem dynamics for montane ecosystems. Dense montane forests are common at moderate elevations, due to moderate temperatures and high rainfall. At higher elevations, the climate is harsher, with lower temperatures and higher winds, preventing the growth of trees and causing the plant community to transition to montane grasslands and shrublands or alpine tundra. Due to the unique climate conditions of montane ecosystems, they contain increased numbers of endemic species. Montane ecosystems also exhibit variation in ecosystem services, which include carbon storage and water supply.
Alpine vegetation refers to the zone of vegetation between the altitudinal limit for tree growth and the nival zone. Alpine zones in Tasmania can be difficult to classify owing to Tasmania's maritime climate limiting snow lie to short periods and the presence of a tree line that is not clearly defined.
Crustose lichens are lichens that form a crust which strongly adheres to the substrate, making separation from the substrate impossible without destruction. The basic structure of crustose lichens consists of a cortex layer, an algal layer, and a medulla. The upper cortex layer is differentiated and is usually pigmented. The algal layer lies beneath the cortex. The medulla fastens the lichen to the substrate and is made up of fungal hyphae. The surface of crustose lichens is characterized by branching cracks that periodically close in response to climatic variations such as alternate wetting and drying regimes.
Ludwig Emanuel Schaerer was a Swiss pastor and lichenologist. Interested in natural history from a young age, Schaerer trained as a teacher and studied theology in Bern. During his career as a teacher, orphanage director, and pastor, he researched extensively and maintained correspondence with foreign botanists interested in cryptogams. Schaerer was best known for his multi-volume work Lichenum Helveticorum Spicilegium, published in 12 parts from 1823 to 1842. This series catalogued and described the lichens of Switzerland, particularly those in the Alps, where he often went on collecting excursions. In another series, he compiled and distributed dried herbarium specimens acquired from his collections. Several lichen taxa have been named in honour of Schaerer.
Buellia frigida is a species of saxicolous (rock-dwelling), crustose lichen in the family Caliciaceae. It was first described from samples collected from the British National Antarctic Expedition of 1901–1904. It is endemic to maritime and continental Antarctica, where it is common and widespread, at altitudes up to about 2,000 m (6,600 ft). The characteristic appearance of this lichen features shades of grey and black divided into small polygonal patterns. The crusts can generally grow up to 7 cm in diameter, although neighbouring individuals may coalesce to form larger crusts. One of the defining characteristics of the lichen is a textured surface with deep cracks, creating the appearance of radiating lobes. These lobes, bordered by shallower fissures, give the lichen a distinctive appearance and textured surface.
Umbilicaria torrefacta is a species of saxicolous (rock-dwelling), foliose lichen in the family Umbilicariaceae. It is an arctic-alpine species with a circumpolar distribution and is widely distributed within the Holarctic realm, specifically within the Palearctic and Neoarctic biogeographical regions. Characteristic features of Umbilicaria torrefacta include the lace-like fringe in its lobes and the plates on the underside of the thallus. One common name, punctured rock-tripe, refers to the distinctive sieve-like perforations on the thallus margins.
Rhizocarpon austroamphibium is a species of saxicolous (rock-dwelling), crustose lichen in the family Rhizocarpaceae. It is found in alpine environments in southwestern Tasmania, Australia.