| 词条 | East European forest steppe |
| 释义 |
|name = Ecoregion: East European forest steppe |image = 20140614 151745 Richtone(HDR).jpg |image_size = 300 |image_alt = |caption = Central Black Earth Nature Reserve, an example of forest steppe terrain, in Kursk Oblast, Russia |map = Ecoregion PA0419.svg |map_size = 300 |map_alt = Ecoregion territory (in purple) |map_caption = Ecoregion territory (in purple) |ecozone = Palearctic |biome = Temperate Broadleaf and Mixed Forests |animals = |bird_species = |mammal_species = |border = |borders = |area = 727269 |country = |countries = Russia, Ukraine, Moldova, Romania and Bulgaria |state = |region_type = |elevation = |coordinates = |geology = |seas = |rivers = |climate = |soil = |conservation = |global200 = |habitat_loss = |habitat_loss_ref = |protected = |protected_ref = }} The East European forest steppe ecoregion (WWF ID:PA0419) is a patchwork of broadleaf forest stands and grasslands (steppe) that stretches 2,100 km across eastern Europe from the middle of Ukraine to the Ural Mountains in Russia. There are also isolated areas of similar character off the western end in eastern Romania, Moldova, and Bulgaria. The region forms a transition zone between the temperate forests to the north, and the steppe to the south. The forest-steppe is an area of Russia in which precipitation and evaporation are approximately equal.[1] The ecoregion is in the Palearctic ecozone, with a Humid Continental climate. It covers {{convert|727269|km2|sqmi|abbr=on}}.[1] Location and descriptionThe ecoregion forms a long band, about 2,100 km long and 600 km wide, from Ukraine in the west to western edge of Siberia at the Ural Mountains in the east. Most of the terrain is rolling hills and some plains. Average elevations range from 150 meters (above sea level) in the lowlands to 250 meters in the hills, with some isolated ranges of low mountains on the edges of the area.[1][1][2]The ecoregion can be divided into sub-provinces from west to east: Dnieper Upland, Dnieper Lowland, Central Russian Upland, Oka-Don Plain, Volga Upland, and the Trans-Volga. Moisture diminishes as the ecoregion stretches to the east, as does the forest fragmentation.[3] ClimateThe region has a Humid continental, cool summer climate (Koppen classification (Dfb)). This climate is characterized by high variation in temperature, both daily and seasonally; with dry winters and cool summers. The "cool summer" designation indicates that at least no month averages above {{convert|22|C|F}}. The summers become hotter and the winters colder as you move east across the ecoregion, due to the movement towards the center of the continent ("continentality"). Flora and faunaFor centuries, scientists have speculated on the causes of variations in stands of trees. It is currently understood that on the macro level, steppes are more arid and that trees thin out in the transition zones. Because the terrain of the ecoregion is relatively flat or low hills, with no physical barriers between the biomes to the north and south, the plant communities tend to be shaped by local variations in water flow. Differences in drainage, variations in soil type (pine trees on sandy soil, deciduous trees on loamy soil, etc.) and salinity, the effects of blowing wind (which drives snow off the hills into depressions, affecting soil quality), and the historic activities of humans all combine to create the mosaic character of the region.[4] Open landscapes show that steppe plant communities can compete with forest. Sedges are characteristic in the steppe areas, resisting low-moisture conditions with much of their biomass underground.[5] ProtectionsThe East European forest steppe has been affected heavily by human pressure: over half is arable land, and the natural forest stands have mostly been cleared. Little of the territory is legally protected as nature reserves, and such reserves that exist tend to be small tracts set aside for study. Representative protected areas in the ecoregion include:
See also
References1. ^1 {{cite web|title=East European forest steppe|url=https://www.globalspecies.org/ecoregions/display/PA0419|website=Ecoregions of the World|publisher=GlobalSpecies.org|access-date=July 23, 2018}} 2. ^{{cite web|title=PA0419: Eastern Europe: Bulgaria, Moldova, Romania, Russia, and Ukraine|url=https://www.worldwildlife.org/ecoregions/pa0419|publisher=World Wildlife Federation|access-date=July 23, 2018}} 3. ^{{cite web|title=Biomes and Regions of Northern Eurasia - Classifications: Zonal and Provincial Differences|url=http://www.rusnature.info/reg/11_5.htm|publisher=Russian Nature|language=|accessdate=August 13, 2018}} 4. ^1 2 {{cite web|title=Biomes and Regions of Northern Eurasia - Steppe and Forest Steppe|url=http://www.rusnature.info/reg/11_1.htm|publisher=Russian Nature|language=|accessdate=August 13, 2018}} 5. ^{{cite web|title=Biomes and Regions of Northern Eurasia - Biological Diversity|url=http://www.rusnature.info/reg/11_6.htm|publisher=Russian Nature|language=|accessdate=August 13, 2018}} External links 3 : Ecoregions of Bulgaria|Ecoregions of Russia|Palearctic ecoregions |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。