Ecosystems the Ukrainian Steppe: Status, Threats and Promises of Sustainability Vladimir V
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15. Hickey RJ (1977) The Lycopodium 18. Cody WJ (1988) Plants of Riding obscurum complex in North America. Mountain National Park, Manitoba. American Fern Journal 67:45-48. Research Branch, Agriculture Canada, Publication 1818/E, Supply and services 16. Holub, J (1975) Diphasiastrum, a Canada, Ottawa, ON. new genus in Lycopodiaceae. Preslia 14: 97-100. 19. Tryon RM Jr (1954) The ferns and fern allies of Minnesota. University of 17. Harms VL (2003) Checklist of the Minnesota Press, Minneapolis, MN. vascular plants of Saskatchewan and the provincially and nationally rare native plants in Saskatchewan, including important synonyms, authorities, common names and various status indicators. University Extension Press, Saskatoon, SK ECOSYSTEMS THE UKRAINIAN STEPPE: STATUS, THREATS AND PROMISES OF SUSTAINABILITY VLADIMIR V. KRICSFALUSY School of Environment and Sustainability, University of Saskatchewan, 330 Kirk Hall, 117 Science Place, Saskatoon SK S7N5C8, Canada [email protected] INTRODUCTION Grassland communities are characterized Grasslands and savannas are found in by rich biodiversity. The vegetation most terrestrial ecoregions of the world is dominated by grasses and other and they cover over 40% of the land graminoids such as sedges. Grasses and surface.1 Following the Pleistocene ice many sedges are particularly suited for ages, grasslands expanded in range in the specific ecological conditions because the hotter and drier climates. Eventually, they have intercalary meristems that allow they became the dominant land feature for continued growth under a grazing worldwide. Nowadays, grasslands occupy regime and help ensure survival in dry more of the earth’s surface than the summers and cold continental winters. other major cover types, i.e. forests Most grassland plants also have a well- or agricultural lands. Along with this developed fibrous root system with a large huge sweep of area, grasslands are an surface area, a characteristic which is immensely important environment for important under the condition of low soil humans, plants and animals. moisture. 104 Blue Jay Grasslands have been heavily used Ukraine and nowadays about 82% of its throughout millennia of human history. steppe area is destroyed. Globally, more people inhabit grasslands than any other biome.1 They provide Most of the American prairies and many goods and services that are vital European steppes were plowed by to humans: biodiversity, food, forage, settlers, due to the extremely fertile soil. livestock, biofuels, carbon storage, This has led to tremendous changes, provision of drinking water, tourism and most recently, the loss of much and recreation, as well as playing of this biome occurred primarily due other important supportive ecosystem to agriculture, fragmentation, invasive functions.2 Grasslands are important exotic species, and the lack of a natural repositories of biodiversity: they form dynamic regime. The movement of herds one-quarter of 142 terrestrial ecoregions of grazing animals and wildfire activity identified as priorities for conservation traditionally held back tree growth and by WWF Global 200 and support nearly invasive species, but with those factors half of all endemic birds and one fifth largely gone, remaining grasslands of plant species.3 Grasslands have are slowly reverting to woodland and been the seedbeds for the ancestors forest. The main threats currently facing of virtually every major cereal crop and grasslands in Canada are changes in the pre-domestication home of our most land use and abandonment of traditional important livestock. activities, afforestation and intensification of grassland management.12,13 A long history of human use and abuse of grasslands has substantially shrunk This short outlook illustrates the their area around the world. Nowadays, importance, multiple functions and threats the Temperate grasslands, savannas to temperate grasslands in different parts and shrublands biome has the least of the world. The question one could ask protection globally with mere 2% in strict is: why people on the Canadian prairies protected areas.4 The greatest loss of should be interested in the Ukrainian grasslands is in North America.5,6 Current steppes? First, the steppes and the estimates indicate that, on average, less prairies have many biological similarities than 20% of original grassland habitats at the generic and even species level. in the Central Plains remain, and only Second, there are many examples of 3.5% has been protected overall within native plant species from one area Canada.7,8 Locally, the loss of different that have become invasive weeds in grassland types can be even greater, the other. Third, plants from the steppe e.g. in Saskatchewan, less than 1% have become important forage and crop remains of the once vast fescue prairie.9 species in the prairie. Fourth, settlers from In Europe, grasslands are mostly of the Ukrainian steppe regions brought anthropogenic origin.10 The exceptions their agricultural expertise, seeds, and are the areas in alpine regions, along culture to the Canadian prairie provinces rivers and remnant fragments of steppe enriching the agricultural and cultural vegetation.11 Vast steppe grasslands that fabric. Therefore, the purpose of this originally extended from south-east to paper is to describe the current state central Europe have been destroyed to of the steppes of Ukraine, identify the a greater degree than any other type of main threats to them, and highlight the vegetation. The last big “taming of the potential for collaboration of Canadian steppe” occurred about 200 years ago in and Ukrainian scientists and practitioners in conserving temperate grasslands. 70 (2) June 2012 105 THE STEPPE ENVIRONMENT than the prairies in North America. Ecology of the Steppe Overall, distribution and structure of Grassland vegetation occurs mainly steppe vegetation in Ukraine depends in lowland areas in the middle latitudes on climate and soil factors, and the main in areas with continental climate, where limiting factor of the vegetation is a lack of the summers are warm and dry and the moisture.15 The mean annual temperature winters are cold. Shortage of rainfall and total precipitation change from south limits the growth of woody plants and to north (from 9-10oC to 7-9oC and from prevents the development of a closed 350 mm to 450 mm, respectively). forest cover. Natural grasslands of the temperate zone of Eurasia are called the The Eurasian steppe landscapes steppes. Russian and Ukrainian were the are characterized by far horizons and languages from which the term “steppe” prevalent flat to undulating relief, mostly at was borrowed (etymology of the word is low altitudes. A typical soil matrix is loess, associated with the space, ground, and which covers varied geological bedrock. plain), first appearing in international The steppe ecosystem gave rise to the botanical terminology in the 18th century. world’s most fertile soils, chernozems (Russian and Ukrainian for “black soils”) The Eurasian steppe stretches from named after their characteristic dark- an enclave in Hungary, where it called coloured humus horizon. The soils within puszta (meaning “bare, empty”), through steppe zone in Ukraine change from a chain of small remnants in Romania light and dark chestnut soils occurring in and Moldova to a vast area of south combination with solonetzic soils, through Ukrainian (Fig. 1) and south Russian southern chornozems, to typical humic plains, north Caucasus, south Ural, chernozems. Chernozem soil types also and north Kazakhstan to south Siberia, occur in the prairies of North America. Mongolia and north-east China.14 Often the Eurasian steppe is divided into three Biodiversity of the Steppe main parts – the Pontic steppe, the The steppes of Ukraine are situated in Kazakh steppe, and the Mongol steppe. the west part of the Eurasian temperate Similar vegetation types can also be found grassland biome and occupy about on other continents. In North America, 300,000 square kilometers. common name for grasslands is the prairies (from French, meaning “a treeless The characteristics of the pristine grassy plain”). They form a triangular steppes of Ukraine were described in the area from Alberta, Saskatchewan, and beginning of the 19th century by Pachoski Manitoba in Canada through the Great (1917)16, Kleopov (1933)17 and some Plains to southern Texas in the USA and other authors. Later, steppes became down to Mexico.12 the subject of intense investigations by many Ukrainian and Russian scientists. The Ukrainian steppe (Mariupol station) Bilyk (1973)18 has summarized data lies within the temperate continental on the steppe vegetation of Ukraine climate zone and in comparison with and gave a critical review of previous the central part of the Eurasian steppe studies. There are zonal (geographical, (Semipalatinsk station, Russia) or central ecological) patterns corresponding to the part of the Canadian prairie (Saskatoon climate and soil patterns of the steppe station), is milder and more moist (Fig. 2). community’s distribution in Ukraine.15 Also, annual precipitation is more evenly Overall, vegetation changes towards the distributed through the steppes in Eurasia south from forest-steppe zone (which 106 Blue Jay Figure 1. Map of the Ukrainian steppe with locations of the visited reserves [see back inside cover for colour version]. 70 (2) June 2012 107 Figure 2. Climate diagrams for temperate grasslands. The diagrams include: name of station, elevation (m above sea level), mean