Biological Data Gateway: Introduction
Biology is a truly interdisciplinary science, especially when it comes
to evaluating living resources at map-level
scales. Most broadly, it is helpful to think of the mapped biological
data you will find in the National Atlas as falling into three broad categories
of information.
The first of these is species, both plant and animal. Maps for a wide
variety of species exist, some delineating distribution, some detailing
abundance, and some demonstrating seasonal ranges. Other maps provide
long-range views of how species populations and habitats have changed
across recent years or even decades.
Biologists and ecologists think of the second category, places, in two
distinct ways. Ecoregions, as the term itself suggests, are defined regionally.
Along
with the land cover and soil conditions that contribute to their identities,
geographical placement upon the continent itself is a primary component
in distinguishing one ecoregion from another. Ecosystems, on the other
hand, are habitat and community types that can occur, with some degree
of variation, in various regions. Wetlands, for instance, are widespread
and can be found in all 50 States.
Third, there are special issues. Something of a catchall category, special
issues cut across place and species considerations to focus on problems
of special concern. Invasive species, endangered species, biodiversity,
contaminants, climate change, and wildlife mortality have been identified
by the Nation's ecologists and biologists as among the most pressing challenges
confronting species and habitats today.
Biological Data Gateway: Species
Although trained scientists play a much more important role today than
they did when Thomas Jefferson called for the first national inventory
of American flora and fauna, citizen naturalists have managed to significantly
preserve their roles in such surveys. This is especially the case when
it comes to the job of collecting data about birds, butterflies, and moths.
Each year, thousands of ordinary citizens contribute their time and expertise
to such studies and provide much of the data that allow us to better understand
the numbers and habits of these species groups.
An increased interest in the ecological sciences and the emergence of
modern digital mapping techniques, however, have helped to create a level
of geographically referenced species data undreamed of in Jefferson's
day. For example, herpetologists - scientists who specialize in reptiles
and amphibians - have created comprehensive range and abundance maps of
numerous species since the 1950s. Likewise, national-scale maps exist
for fishes, mammals, vegetation, and, in addition to moths and butterflies,
other invertebrates as well.
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