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37-749: The region of Hotzenwald is not precisely defined in the records. In a narrower sense the Hotzenwald is the southernmost region of the Southern Black Forest, bounded in the west roughly by the Wehra , in the north approximately by the upper reaches of the Alb River near St. Blasien , in the east by the hill ridge between the Alb and Schlücht rivers, and in the south by the High Rhine and Klettgau rivers. This definition of

74-537: A temperate grassland , restricting southern tundra to coastal Antarctica and its islands. The flora and fauna of Antarctica and the Antarctic Islands (south of 60° south latitude) are protected by the Antarctic Treaty . Alpine tundra does not contain trees because the climate and soils at high altitude block tree growth. The cold climate of the alpine tundra is caused by the low air temperatures, and

111-750: A local climate in which at least one month has an average temperature high enough to melt snow (0 °C (32 °F)), but no month with an average temperature in excess of 10 °C (50 °F). The cold limit generally meets the EF climates of permanent ice and snows ; the warm-summer limit generally corresponds with the poleward or altitudinal limit of trees, where they grade into the subarctic climates designated Dfd , Dwd and Dsd (extreme winters as in parts of Siberia ), Dfc typical in Alaska, Canada, mountain areas of Scandinavia , European Russia , and Western Siberia (cold winters with months of freezing). Despite

148-479: A river in Baden-Württemberg is a stub . You can help Misplaced Pages by expanding it . Tundra In physical geography , tundra ( / ˈ t ʌ n d r ə , ˈ t ʊ n -/ ) is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: Arctic tundra, alpine tundra , and Antarctic tundra. Tundra vegetation

185-660: A similar period, is an indication of the first settlement of the Hotzenwald. Around 1,000 A. D. spruce superseded beech as the predominant tree species. The raised bogs ( Hochmoore ) and transitional bogs ( Übergangsmoore ) especially in the Ibach / Dachsberg area, as a relic of the ice age, are home to a rich variety of species otherwise rare in the Black Forest such as bog-rosemary , mud sedge and fewflower sedge , rannoch-rush , alpine bulrush , white beak-sedge or purple coltsfoot . The European Arctic starflower has

222-450: A strong presence in the Hotzenwald, which is also the only place in the whole of South Germany where the cross-leaved heath occurs naturally. Especially in the first half of the 20th century, the forestry industry’s attempts at drainage drastically reduced the number of bogs. As a result, several bogs in the Hotzenwald were declared as nature reserves ; in 1998 there were 10 of them. In addition, attempts have been made to regenerated some of

259-479: Is a risk of wildfire, such as the 1,039 km (401 sq mi) of tundra which burned in 2007 on the north slope of the Brooks Range in Alaska. Such events may both result from and contribute to global warming. Carbon emissions from permafrost thaw contribute to the same warming which facilitates the thaw, making it a positive climate change feedback . The warming also intensifies Arctic water cycle , and

296-449: Is characterized by plants that grow close to the ground, including perennial grasses , sedges , forbs , cushion plants , mosses , and lichens . The flora is adapted to the harsh conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation, and a short growing season. Tundra climates ordinarily fit the Köppen climate classification ET , signifying

333-430: Is composed of dwarf shrubs , sedges , grasses , mosses , and lichens . Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus . The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in

370-630: Is light, evaporation is also relatively minimal. During the summer, the permafrost thaws just enough to let plants grow and reproduce, but because the ground below this is frozen, the water cannot sink any lower, so the water forms the lakes and marshes found during the summer months. There is a natural pattern of accumulation of fuel and wildfire which varies depending on the nature of vegetation and terrain. Research in Alaska has shown fire-event return intervals (FRIs) that typically vary from 150 to 200 years, with dryer lowland areas burning more frequently than wetter highland areas. The biodiversity of tundra

407-694: Is low: 1,700 species of vascular plants and only 48 species of land mammals can be found, although millions of birds migrate there each year for the marshes. There are also a few fish species. There are few species with large populations. Notable plants in the Arctic tundra include blueberry ( Vaccinium uliginosum ), crowberry ( Empetrum nigrum ), reindeer lichen ( Cladonia rangiferina ), lingonberry ( Vaccinium vitis-idaea ), and Labrador tea ( Rhododendron groenlandicum ). Notable animals include reindeer (caribou), musk ox , Arctic hare , Arctic fox , snowy owl , ptarmigan , northern red-backed voles , lemmings ,

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444-404: Is similar to polar climate . Alpine tundra is generally better drained than arctic soils. Alpine tundra transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone (the treeline ) are known as Krummholz . Alpine tundra can be affected by woody plant encroachment . Alpine tundra occurs in mountains worldwide. The flora of the alpine tundra

481-569: The Kerguelen Islands . Most of Antarctica is too cold and dry to support vegetation, and most of the continent is covered by ice fields or cold deserts. However, some portions of the continent, particularly the Antarctic Peninsula , have areas of rocky soil that support plant life. The flora presently consists of around 300–400 species of lichens, 100 mosses, 25 liverworts , and around 700 terrestrial and aquatic algae species, which live on

518-468: The mosquito , and even polar bears near the ocean. Tundra is largely devoid of poikilotherms such as frogs or lizards. Due to the harsh climate of Arctic tundra, regions of this kind have seen little human activity, even though they are sometimes rich in natural resources such as petroleum , natural gas , and uranium . In recent times this has begun to change in Alaska , Russia, and some other parts of

555-472: The permafrost , making the tundra soil a carbon sink . As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained greenhouse gases into the atmosphere, creating a feedback cycle that changes climate. The term is a Russian word adapted from the Sámi languages . Arctic tundra occurs in the far Northern Hemisphere , north of

592-472: The taiga belt. The word "tundra" usually refers only to the areas where the subsoil is permafrost , or permanently frozen soil. (It may also refer to the treeless plain in general so that northern Sápmi would be included.) Permafrost tundra includes vast areas of northern Russia and Canada. The polar tundra is home to several peoples who are mostly nomadic reindeer herders, such as the Nganasan and Nenets in

629-533: The Hotzenwald are gneisses and migmatites , which were formed in the Palaeozoic era. The largest part of the Hotzenwald is the granite countryside between Bernau and Bad Säckingen . The granite rocks that occur here are, according to research, up to 335 million years old. Other elements of the terrain are granite porphyry and lamprophyre . Near Laufenburg, the Kleiner Laufen rapids broke through

666-457: The Hotzenwald more or less covers the same area as the territory of the former County of Hauenstein . In a wider sense, other regions may be counted as part of the Hotzenwald that were linked to St. Blaise Abbey or the County of Hauenstein, both of which were historically important in the Southern Black Forest. These additional areas include, for example, the parish of Gersbach (Schopfheim) , which

703-623: The Riß ice age indicate that the glacier flowed from the Alps to a point north of Waldshut-Tiengen. A confluence of the Black Forest Glacier and the Alpine Glacier is highly unlikely to have taken place. After the ice age the Hotzenwald region experienced a tundra climate. There is evidence of beech being the dominant species of tree up to 600 B. C.. In addition, grain pollen, which dates to

740-583: The areas of exposed rock and soil around the shore of the continent. Antarctica's two flowering plant species, the Antarctic hair grass ( Deschampsia antarctica ) and Antarctic pearlwort ( Colobanthus quitensis ), are found on the northern and western parts of the Antarctic Peninsula. In contrast with the Arctic tundra, the Antarctic tundra lacks a large mammal fauna, mostly due to its physical isolation from

777-536: The basement of the Black Forest rocks in their lower reaches. They follow the downslope of the Southern Black Forest from north to south before emptying into the Rhine as right-hand tributaries. The main rivers in the Hotzenwald region, from west to east, are the Wiese, Wehra, Murg , Alb, and Schlücht. The parishes in the heart of the region are Rickenbach , Herrischried , Dachsberg and Görwihl . The oldest rocks occurring in

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814-501: The basement; today they are impounded. In the eastern and southeastern Hotzenwald platform rocks cover the basement. According to field research in the area of Waldshut / Dogern this layer of bunter sandstone is an average of 15 metres thick and divided into three elements: the upper stratum of 8 metre thick Röt clays ; beneath it a roughly 5 metre thick sandstone layer mixed with carnelian (the Carnelian horizon); and, at

851-556: The bottom, above the basement, a roughly 2.5-metre-thick stratum of Mühl sandstone. During the Würm glaciation the Alb valley glacier covered the Hotzenwald from the north to just before Görwihl. The extent of the Black Forest Glacier of the Riß glaciation is no longer precisely known today, but it appears to have extended from the north as well as far as Hottingen . The finds from the Alpine gravels of

888-483: The climate system activated around 2 °C (3.6 °F) of global warming suggested that at this threshold, permafrost thaw would add a further 0.09 °C (0.16 °F) to global temperatures by 2100, with a range of 0.04–0.16 °C (0.07–0.29 °F) Antarctic tundra occurs on Antarctica and on several Antarctic and subantarctic islands, including South Georgia and the South Sandwich Islands and

925-488: The increased amounts of warmer rain are another factor which increases permafrost thaw depths. The IPCC Sixth Assessment Report estimates that carbon dioxide and methane released from permafrost could amount to the equivalent of 14–175 billion tonnes of carbon dioxide per 1 °C (1.8 °F) of warming. For comparison, by 2019, annual anthropogenic emission of carbon dioxide alone stood around 40 billion tonnes. A 2018 perspectives article discussing tipping points in

962-500: The level of the High Rhine (about 300 m above  sea level (NN) ) up to heights of 500 to over 1,000 m above NN across the majority of the area. The region drops from the summits of the Southern Black Forest in the north to the High Rhine in the south and is characterised by sunny plateaux and high valleys . The rivers in the Hotzenwald generally form high valleys in their upper reaches and cut deeply into

999-542: The old bogs. The forests in the Ibach/Dachsberg area and the Upper Forest (Oberwald) consist mainly of firs , beech and spruce. In the poorly drained hollows these are interrupted by bogs or spruce woods. In the second half of the 20th century, several areas of highland pasture were turned into forests. Likewise during this period, reforestation of the steep heads of the valleys, mountainsides and unused valley grasslands

1036-478: The only subantarctic orchids; the royal penguin ; and the Antipodean albatross . There is some ambiguity on whether Magellanic moorland , on the west coast of Patagonia , should be considered tundra or not. Phytogeographer Edmundo Pisano called it tundra ( Spanish : tundra Magallánica ) since he considered the low temperatures key to restrict plant growth. More recent approaches have since recognized it as

1073-607: The other continents. Sea mammals and sea birds, including seals and penguins, inhabit areas near the shore, and some small mammals, like rabbits and cats, have been introduced by humans to some of the subantarctic islands. The Antipodes Subantarctic Islands tundra ecoregion includes the Bounty Islands , Auckland Islands , Antipodes Islands , the Campbell Island group , and Macquarie Island . Species endemic to this ecoregion include Corybas dienemus and Corybas sulcatus ,

1110-614: The permafrost area (and the Sami in Sápmi ). Arctic tundra contains areas of stark landscape and is frozen for much of the year. The soil there is frozen from 25 to 90 cm (10 to 35 in) down, making it impossible for trees to grow there. Instead, bare and sometimes rocky land can only support certain kinds of Arctic vegetation , low-growing plants such as moss, heath ( Ericaceae varieties such as crowberry and black bearberry ), and lichen . There are two main seasons, winter and summer, in

1147-413: The polar tundra areas. During the winter it is very cold, dark, and windy with the average temperature around −28 °C (−18 °F), sometimes dipping as low as −50 °C (−58 °F). However, extreme cold temperatures on the tundra do not drop as low as those experienced in taiga areas further south (for example, Russia's, Canada's, and Alaska's lowest temperatures were recorded in locations south of

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1184-522: The potential diversity of climates in the ET category involving precipitation, extreme temperatures, and relative wet and dry seasons, this category is rarely subdivided, although, for example, Wainwright, Alaska can be classified ETw and Provideniya, Russia ETs , with most of the rest of the tundra fitting into the ETf subcategory. Rainfall and snowfall are generally slight due to the low vapor pressure of water in

1221-444: The subject of habitat conservation programs. In Canada and Russia, many of these areas are protected through a national Biodiversity Action Plan . Tundra tends to be windy, with winds often blowing upwards of 50–100 km/h (30–60 mph). However, it is desert-like, with only about 150–250 mm (6–10 in) of precipitation falling per year (the summer is typically the season of maximum precipitation). Although precipitation

1258-412: The tree line). During the summer, temperatures rise somewhat, and the top layer of seasonally-frozen soil melts, leaving the ground very soggy. The tundra is covered in marshes, lakes, bogs, and streams during the warm months. Generally daytime temperatures during the summer rise to about 12 °C (54 °F) but can often drop to 3 °C (37 °F) or even below freezing. Arctic tundras are sometimes

1295-588: The world: for example, the Yamalo-Nenets Autonomous Okrug produces 90% of Russia's natural gas. A severe threat to tundra is global warming , which causes permafrost to thaw. The thawing of the permafrost in a given area on human time scales (decades or centuries) could radically change which species can survive there. It also represents a significant risk to infrastructure built on top of permafrost, such as roads and pipelines. In locations where dead vegetation and peat have accumulated, there

1332-503: Was begun. By contrast, the terraced slopes of the outer forests were largely cleared. On the high pastures the winged greenweed plays an important role. 47°39′N 8°02′E  /  47.650°N 8.033°E  / 47.650; 8.033 Wehra Wehra is a river of Baden-Württemberg , Germany . It passes through Todtmoos and Wehr and flows into the Rhine downstream of Bad Säckingen . This article related to

1369-532: Was first mentioned in 1166 by the gift of a church to St Blaise Abbey. This parish lies immediately northwest of the Wehra. Others include the regions in the northwest as far as the middle and upper reaches of the Wiese river and in the east to the hill ridge between Schlücht and Steina rivers. Whichever definition is used, the region mainly covers the central and high areas of the Southern Black Forest. It climbs rapidly from

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