Building upon existing classification systems of natural environments, this visually-oriented guide--from the Arctic Circle to Central America--advocates a universal, biogeographic standard for inventorying regional habitats as now used by the Environmental Protection Agency and some state agencies. The separate digitized map, dramatically unfolding to 42x42", is color-coded to depict gradients in moisture and temperature: factors which delimit vegetation and adaptations by flora and fauna. Annotation copyrighted by Book News, Inc., Portland, OR
Biotic Communities catalogs and defines by biome, or biotic community, the region centered on Arizona, New Mexico, Sonora, Chihuahua, and Baja California Norte, plus portions of California, Nevada, Utah, Colorado, Texas, Coahuila, Sinaloa, and Baja California Sur. This ambitious guide is an essential companion for anyone working in natural resources management and ecological research, as well as nonspecialists looking for solid information about a particular southwestern locale. Biotic Communities is arranged by climatic formation with a short chapter for each biome describing climate, physiognomy, distribution, dominant and common plant species, and characteristic vertebrates. Subsequent chapters contain careful descriptions of zonal subdivisions.
This volume represents a first attempt at holistically classifying and mapping ecological regions across all three countries of the North American continent. A common analytical methodology is used to examine North American ecology at multiple scales, from large continental ecosystems to subdivisions of these that correlate more detailed physical and biological settings with human activities on two levels of successively smaller units. The volume begins with an overview of North America from an ecological perspective, concepts of ecological regionalization. This is followed by descriptions of the 15 broad ecological regions, including information on physical and biological setting and human activities. The final section presents case studies in applications of the ecological characterization methodology to environmental issues. The appendix includes a list of common and scientific names of selected species characteristic of the ecological regions.
South American ecosystems suffered one of the greatest biogeographical events, after the establishment of the Panamian land bridge, called the “Great American Biotic Interchange” (GABI). This refers to the exchange, in several phases, of land mammals between the Americas; this event started during the late Miocene with the appearance of the Holartic Procyonidae (Huayquerian Age) in South America and continues today. The major phases of mammalian dispersal occurred from the Latest Pliocene (Marplatan Age) to the Late Pleistocene (Lujanian Age). The most important and richest localities of Late Miocene-Holocene fossil vertebrates of South America are those of the Pampean region of Argentina. There are also several Late Miocene and Pliocene localities in western Argentina and Bolivia. Other important fossils have been collected in localities of Pleistocene age outside Argentina: Tarija (Bolivia), karstic caves of Lagoa Santa and the recently explored caves of Tocantins (Brasil), Talara (Perú), La Carolina (Ecuador), Muaco (Venezuela), and Cueva del Milodon (Chile), among others. The book discusses basic information for interpreting the GABI such as taxonomic composition (incorporating the latest revisions) at classical and new localities for each stage addressing climate, environments, and time boundaries for each stage. It includes the chronology and dynamics of the GABI, the integration of South American mammalian faunas through time, the Quaternary mammalian extinctions and the composition of recent mammalian fauna of the continent.
North America contains an incredibly diverse array of naturalenvironments, each supporting unique systems of plant and animallife. These systems, the largest of which are biomes, formintricate webs of life that have taken millennia to evolve. Thisrichly illustrated book introduces readers to this extraordinaryarray of natural communities and their subtle biological andgeological interactions. Completely revised and updated throughout, the second edition ofthis successful text takes a qualitative, intuitive approach to thesubject, beginning with an overview of essential ecological termsand concepts, such as competitive exclusion, taxa, niches, andsuccession. It then goes on to describe the major biomes andcommunities that characterize the rich biota of the continent,starting with the Tundra and continuing with Boreal Forest,Deciduous Forest, Grasslands, Deserts, Montane Forests, andTemperature Rain Forest, among others. Coastal environments,including the Laguna Madre, seagrasses, Chesapeake Bay, and barrierislands appear in a new chapter. Additionally, the book covers manyunique features such as pitcher plant bogs, muskeg, the polar icecap, the cloud forests of Mexico, and the LaBrea tar pits.“Infoboxes” have been added; these include biographiesof historical figures who provided significant contributions to thedevelopment of ecology, unique circumstances such as frogs andinsects that survive freezing, and conservation issues such asthose concerning puffins and island foxes. Throughout the text,ecological concepts are worked into the text; these includebiogeography, competitive exclusion, succession, soil formation,and the mechanics of natural selection. Ecology of North America 2e is an ideal first text forstudents interested in natural resources, environmental science,and biology, and it is a useful and attractive addition to thelibrary of anyone interested in understanding and protecting thenatural environment.
The geological closure of the Isthmus of Panama (IP) precipitated one of the greatest biogeographic events of the Cenozoic that indelibly changed composition of biotic communities in South and North America. The precise timing of uplift and final closure of the IP continues to be a topic of intense debate in geology and evolutionary biology. The traditional or Young Isthmus model states that the definitive closure of the IP occurred between 4 and 3 million years ago (Ma). The more recently proposed Old Isthmus model states that the IP was completed during the middle Miocene (15 to 13 Ma). Regardless of the closure data, the fossil record makes clear that at 2.7 Ma began the Great American Biotic Interchange (GABI), a massive interchange of mammalian lineages, many affiliated with dry and open environments. For the Old Isthmus hypothesis to be viable, one must posit the existence of some non-oceanic barrier that delayed the interchange between continents for some 10 million years. Here, we tested the hypothesis that an environmental barrier in the form of a humid, closed-canopy forest was present on the IP prior to the Pleistocene interchange and glacial cycling. Scant paleoenvironmental data are available from the Neogene IP, so here we test our hypothesis indirectly using comparative phylogeography of 69 species of anurans by reconstructing their environmental affinities and estimating the timing of interchange between continents for each lineage. We found that frog species with a preference for dry and open environments all moved between continents after 3 Ma, while the mean date of interchange for those associated with humid forests was 6.1 Ma, including some more recently than 3 Ma. Semi-arid species crossed significantly later than humid forest species, as predicted by the hypothesis that a humid, closed-canopy forest barrier existed during the Late Miocene.
