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Appendix A: Air Masses and Frontal Zones

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Appendix A: Air Masses and Frontal Zones Appendix A: Air Masses and Frontal Zones A body of air in which the temperature and properties of an air mass are derived partly moisture are fairly uniform over a large area from the regions over which it passes. Those is known as an air mass. The boundary land or ocean surfaces that strongly impress between a given air mass and its neighbor is their characteristics on the overlying air masses usually sharply defined. This discontinuity is are called source regions. Air masses are clas- termed a front. In the convergence zone sified according to their latitudinal position between the tropical polar air masses, winds (which determines thermal properties), and are variable and high, and accompanied by underlying surface, whether continent or ocean stormy weather. This zone is called the (determining moisture content). They are polar front. A large number of the Earth’s summarized in Table 1 and illustrated in Fig. 1. cyclonic storms are generated here. The R.G. Bailey, Ecoregions, DOI 10.1007/978-1-4939-0524-9, # Springer Science+Media, LLC 2014 141 142 Appendix A: Air Masses and Frontal Zones Table 1 Properties of air massesa Properties of Major group Subgroup Source region source Polar (including Polar continental Arctic Basin; northern Eurasia and northern North Cold, dry, very arctic) (cP) America; Antarctica stable Polar maritime Oceans poleward of 40 or 50 Cool, moist, (mP) unstable Tropical (including Tropical Low-latitude deserts, especially Sahara and Hot, very dry, equatorial) continental (cT) Australian Deserts stable Tropical Oceans of tropics and subtropics instability toward Warm, moist, maritime (mT) west side of ocean greater aFrom Trewartha et al. (1967) Fig. 1 Source regions of air masses in relation to the polar front and the intertropical convergence zone (ITC). From Elements of Physical Geography, 4th ed., by Arthur N. Strahler and Alan H. Strahler, p. 125. Copyright (c) 1989 by John Wiley & Sons, Inc.; reproduced with permission Appendix B: Common and Scientific Names Oak, cork Quercus suber Plants Ocotillo Fouquieria splendens Acacia Acacia Pine Pinus Ash Fraxinus Pine, lodgepole Pinus contorta Aspen, quaking Populus tremuloides Pine, ponderosa Pinus ponderosa Basswood (linden) Tilia Plum pine Podocarpus Beech, southern Nothofagus Popular (cottonwood) Populus Birch Betula Pinyon Pinus edulis Blackeyed Susan Rudbeckia hirta Redcedar, western Thuja plicata Bluestem, big Andropogon gerardii Redwood Sequoia Bluestem, little Schizachyrium sempervirens scoparium Sagebrush Artemisia Buffalograss Bouteloua Smoketree Psorothamnus dactyloides spinosus Cactus apple (prickly-pear) Opuntina engelmanni Spruce Picea Cactus, saguaro Carnegiea gigantea Spruce, white Picea glauca Cedro espino Pachira quinata Sunflower, common Helianthus annuus Cheatgrass Bromus tectorum Tamarisk (salt-cedar) Tamarix gallica Chestnut (American) Castanea dentata Tuliptree Liriodendron Creosote bush Larrea tridentata tulipifera Douglas-fir Pseudotsuga Walnut Juglans menziesii Willow Salix Eucalyptus (gum) Eucalyptus Animals Elm Ulmus Antelope (see pronghorn) Fir Abies Badger, American Taxidea taxus Hemlock Tsuga Bear Ursidae Hemlock, western Tsuga heterophylla Bear, polar Ursus maritimus Hickory Carya Beaver, American Castor canadensis Hornbeam, American Carpinus caroliniana Bison, American Bison bison Juniper Juniperus Bongo Tragelaphus Kauri Agathis australis eurycerus Larch (tamarack) Larix Buffalo, African (Cape Syncerus caffer Laurel Kalmia buffalo) Locoweed Oxytropis Camel Camelus Magnolia Magnolia Caribou (reindeer) Rangifer tarandus Maple Acer Chipmunk Tamias Maple, sugar Acer saccharum Chipmunk, alpine Tamias alpinus Mesquite Prosopis Crocodile Crocodylus Oak Quercus Deer Cervidae (continued) (continued) R.G. Bailey, Ecoregions, DOI 10.1007/978-1-4939-0524-9, # Springer Science+Media, LLC 2014 143 144 Appendix B: Common and Scientific Names Elephant, African bush Loxodonta africana Moose, American Alces americanus Elephant seal, southern (sea Mirounga leonina Moose, Eurasian (elk) Alces alces elephant) Muskox Ovibos moschatus Elk (red deer) Cervus elaphus Okapi Okapia johnstoni Elk, American (elk, wapiti) Cervus elaphus Panther (see puma) canadensis Penguin Spheniscidae Ermine Mustela erminea Pika, American Ochotona princeps Fox Vulpes and Alopex Plover Pluvialis and Gnu (see wildebeest) Charadrius Goat, mountain Oreamnos Prairie dog Cynomys americanus Pronghorn (antelope) Antilocapra Guanaco Lama glama americana guanicoe Puma (mountain lion, panther) Puma concolor Hamster Muridae: Cricetidae Reindeer (see caribou) Hare, arctic Lepus arcticus Sable Martes zibellina Hippopotamus, common Hippopotamus Sea elephant (see elephant amphibius seal) Hog sucker, northern Hypentelium Turkey, wild Meleagris gallopavo nigricans Walrus Odobenus rosmarus Ibex Capra ibex Whale, blue Balaenoptera Kiwi Apteryx musculus Krill Euphausia superba Whale, fin (finback) Balaenoptera Lemming Dicrostonyx and physalus Lemmus Wildebeest, blue (gnu) Connochaetes Lemur Lemuridae taurinus Lion, mountain (see puma) Wolf, gray Canis lupus Marmot, yellow-bellied Marmota flaviventris Zebra, Burchell’s Equus burchelli Marten, American Martes americana Mink, American Neovison vison (continued) Appendix C: Conversion Factors For readers who wish to convert measurements from the metric system of units to the inch–pound–Fahrenheit system, conversion factors are listed below. Multiply By To obtain Millimeters 0.039 Inches Centimeters 0.394 Inches Meters 3.281 Feet Kilometers 0.621 Miles Square meters 10.764 Square feet Square kilometers 0.386 Square miles Hectares 2.471 Acres Centigrade 1.8 + 32 Fahrenheit R.G. Bailey, Ecoregions, DOI 10.1007/978-1-4939-0524-9, # Springer Science+Media, LLC 2014 145 Appendix D: Comparison of Ecoregion and Related Approaches This appendix provides relevant information ecoregions are based on both biotic and abiotic about the currently available climatic, biotic, features. A geologist might look at a given area in and ecological regionalization maps that cover terms only of geologic formations and structures. the whole globe or large parts of it. An account of In fact, a geologist produced one of the best- the relationship between climate and vegetation, known physiographic maps of the United States and the theory behind defining ecological zones, with this perspective (Fenneman 1928). Where or ecoregions, is given in the main text of this major physiographic discontinuities occur— book. Olstad (2012) reviews the concepts and where mountains meet plains, or where igneous uses of ecoregions and the process of ecoregio- rock ends and sedimentary rock begins—the nalization to illustrate the traditions and boundaries often coincide with changes in the philosophies within the discipline of geography. biota; quite simply: changes in the land can corre- Ecoregions for environmental management is the late to changes in flora and its associated fauna. In subject of a special issue of Environmental Man- areas of little relief, such as the Great Plains, little agement (Loveland 2004). The ecoregions col- or no correlation exists between the geologist’s lection of the Encyclopedia of Earth (Cleveland concept of physiography and the biologist’s con- 2011) holds the results from several of the most cept of ecology. widely used systems to delineate ecoregions. A biologist (c.f. Dice 1943) might examine the The global maps described below primarily same area as the geologist but in terms of the define climatic ecological zones. Some of them, biota’s spatial patterns. Large, relatively homo- such as the World Wildlife Fund (WWF) maps, geneous units of biota at the regional scale are emphasize differences in biogeography or spe- known as biomes (Clements and Shelford 1939; cies origins. Some regional and national maps Brown et al. 1998). Heinrich Walter (1984) refers also emphasize the biogeographical/phyloge- to these as zonobiomes because they are based on netic aspect. Other maps are empirical in that large climatic zones. Subdivisions of biomes they are based on cluster analysis of data or have been mapped by Miklos Udvardy (1975) overlay of thematic maps to identify relative after work started by Raymond Dasmann homogeneous areas. But before we review the (1972); these subdivisions are called “biogeo- various ecological regionalization maps, we graphic provinces.” However, biota constantly look first at other related approaches. changes due to disturbance and succession. For example, either fire or timber harvesting may destroy a forest causing flora-specific fauna either Ecoregions Versus Other Land to emigrate or to perish; either outcome produces Divisions a profound but temporary absence. As the succes- sion process restores the forest to predisturbance Contrasting other land-division categories such as conditions, most if not all of the fauna will repop- physiographic regions and biotic areas (also ulate the forest, though it will do so at varying called “biotic provinces” or “bioregions”), rates according to species. Additionally but quite R.G. Bailey, Ecoregions, DOI 10.1007/978-1-4939-0524-9, # Springer Science+Media, LLC 2014 147 148 Appendix D: Comparison of Ecoregion and Related Approaches separately, the geographic distribution of animal world—the term “ecoregion” is comparable to species or communities may change due to hunt- those regions referred to by other authors. Spe- ing, a circumstance usually independent of habi- cific examples would include, among others, the tat loss. This reality needs to be understood in a following seminal contributions:
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