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COWEETA LTER GLOSSARY OF TERMS
Acidic Deposition
The process by which acids are deposited
in rain, snow, etc., called "wet deposition", and in "dry deposition", when
particles such as fly ash, sulphates and nitrates, and gases such as sulphur
dioxide and nitric oxide are deposited on, or adsorbed onto, surfaces. The dry
particles or gases can be converted into acids after deposition or absorption
when they contact water (Canada, House of Commons 1981).
Algal
Periphyton Assemblages
Allochthonous
Anthropogenic
Scientists have a word we use to
distinguish changes that people have introduced to the environment from
processes which are natural -- anthropogenic. Consider the very fine particles
of dust or smoke suspended in the atmosphere which we call aerosols. If we are
talking about aerosols originating from, say, industrial pollution, we would
call them anthropogenic aerosols. This indicates how they are different from
aerosols originating in dust storms, volcanoes or natural burning.
Archaic People
Individuals that lived during the archaic period (ca. 8000 - 1000 B.C.).
This period was divided up into early, middle, and late. The Archaic period was
characterized by great climatic changes. Until the stabilization of what we now
have as modern climate (about 5,000 years ago), the archaic period began with
cold and wet weather (after the Ice Age) and later, dry and warm weather.
The climate changes allowed different plants and animals to thrive and, as the
large Ice Age animals became scarce and disappeared, people adapted to these
changes in order to survive. Early Archaic peoples tended to occupy brief,
transitory camps widely scattered along floodplain levees and terraces. They
lived in a series of small hunter-gatherer bands and were constantly on the
move. Each band usually had a base camp or series of such repeatedly used
settlements close to diverse food resources like game and wild vegetable foods.
The base camp itself was used by several households, living separately in
shelters scattered along a river terrace. Early Archaic peoples turned from
big-game hunting to the exploitation of forest mammals like the white-tailed
deer as well as to nuts and plant foods. They usually subsisted on a diet of
white-tailed deer, supplemented with black bear and other mammals like elk, fox,
opossum, raccoon, squirrel, and rabbit.
Aquatic Ecologist
An
individual that studies the ecological traits of aquatic systems.
Aquatic Ecosystem
A dynamic
complex of plant, animal and micro-organism communities and their non-living
environment interacting as a functional unit within water.
Aquatic Research at
Coweeta LTER
Aquatic research at Coweeta is facilitated by the detailed characterization of
hydrologic regimes in small (3 ha) to large (760 ha) watersheds, some of which
have been monitored since 1934. These catchments provide one of the longest
continuous hydrologic records in the world. Aquatic research has investigated
the influences of water chemistry, decomposition, organic detritus dynamics, and
stream bed morphology on the relationship of stream primary and secondary
productivity, trophic levels, micro- and macro-arthropod populations, and fish
abundance and diversity.
Basal Area
The cross section area of the stem or stems of a plant
or of all plants in a stand, generally expressed as square units per unit area.
Tree basal is used to determine percent stocking. For shrubs and herbs it is
used to determine phytomass. Grasses, forbs, and shrubs usually measured at or
less then 1 inch above soil level. Trees - the cross section area of a tree stem
in square feet commonly measured at breast height (4.5' above ground) and
inclusive of bark, usually computed by using d.b.h. or tallied through the use
of basal area factor angle gauge.
Biodiversity
Biodiversity,
or biological diversity, is the term for the variety of life and the natural
processes of which living things are a part. This includes the living organisms
and the genetic differences between them and the communities in which they
occur. The concept of biodiversity represents the ways that life is organized
and interacts on our planet. These interactions can take place on scales ranging
from the smallest, at the chromosome level, to organisms, ecosystems, and even
to entire landscapes.
Biomass
A general term for living material –
plants, animals, fungi, bacteria
Biota
Biotic
Pertaining to any aspect of
life, especially to characteristics of entire populations or ecosystems.
Budburst
Canopy Trees
The trees that make up the highest layer
of leaf cover in a forest.
Carbon Storage
Carbon storage can
take place above ground and below ground. Trees store carbon above ground, while
carbon enters the soil through trees below ground. It is more difficult to
measure below ground storage of carbon then above ground storage. Factors
including soil and water quality, the climate and types of trees will determine
if more carbon can be stored above ground or below ground. Soil disturbance is
also a strong factor in the loss of carbon into the atmosphere (Carbon flux-
when carbon is released from where it is stored. Each year about 8 billion
metric tons of carbon is released into the atmosphere through deforestation and
the use of fossil fuels. The majority of this carbon dioxide is removed from the
atmosphere by plants or the ocean, but a significant portion remains airborne.
∂13 C
Virtually every life form on earth takes in isotopes of
carbon, including 14C and 13C, for growth and food. The relative amount of
carbon isotopes in the cells differs with each plant and animal because of a
process called fractionation. Isotopic fractionation occurs when the absorption
of one isotope is favoured over another, often because of the energy differences
between isotopes. For instance, during photosynthesis the isotope 12C is
preferred over 14C. This leaves the plant cells with less 14C for each atom of
12C than in the atmosphere. When this occurs, we say the plant tissue is
depleted in 14C and enriched in 12C. ∂13C indicates the difference between the
sample's 13C/12C ratio and that of a standard. When the value is negative, it
means that the isotope 13C is depleted compared to the standard. The more
negative it is, the more fractionation has occurred.
Cation
An atom or group of atoms with a positive
charge.
Community Ecology
A community is defined as an association of interacting
populations, usually defined by the nature of their associations or the habitat
they use. Community ecology is the study of the processes of these interacting
populations.
Deadfall Traps
Defoliation
Depsides
Detrius
DRG (Digital
Raster Graphic)
Commonly used in GIS
and mapping applications, DRG's are simply digital versions of USGS
topographic maps. Obtainable at a variety of resolutions, DRG's contain
contour information, locations of roads, towns, cities, forests, water (lakes,
rivers, wetlands), as well as many other features that one might expect to find
on a map.
Early Successional
The earliest stage of
development in a ecosystem. An example: vegetative habitat where early
successional is seen as old fields, brushy shrubby type plants, with species
that are shade intolerant.
Ecosystem
A dynamic complex of plant, animal and
micro-organism communities and their non-living environment interacting as a
functional unit. This definition does not specify any particular spatial unit or
scale. Thus, the term "ecosystem" does not, necessarily, correspond to the terms
"biome" or "ecological zone", but can refer to any functioning unit at any
scale. Indeed, the scale of analysis and action should be determined by the
problem being addressed. It could, for example, be a grain of soil, a pond, a
forest, a biome or the entire biosphere. In the words of Eugene Odum "the
grandfather of ecology" an ecosystem is a unit of biological organization
interacting with the physical environment such that the flow of energy and mass
leads to a characteristic trophic structure and material cycles.
Elevational Gradient
Endemism
Environmental Driving Variables
Environmental organisms, processes, or
entities that are responsible for immediate changes in the environment (e.g.,
local climate, soil and water nutrient levels, disturbance dynamics).
Environmental Heterogeneity
On the simplest level, heterogeneity can be
defined as "with parts that are different". Environmental heterogeneity is
resource patchiness.
Extirpation
Extirpation means to no longer existing
in the area of interest.
Fish Shocking or Electrofishing
In order to count all types of fish in a portion of a stream without missing
too many researchers use an electro-shocker. This is the technique of
passing electric current through the water to attract and stun fish, thus
facilitating their capture. Electro-fishing is commonly done on foot using a
backpack-shocking device.
Flavonoids
Foliar
Phenolics
Funnel Traps
Gap Study
Gap studies attempt to evaluate the
effects of gaps in canopies created as the result of natural events and human
intervention. Forest succession in canopy gaps is evaluated at Coweeta
LTER. We are currently measuring microclimatic variables, N mineralization,
and seedling physiology in the gaps that complement long-term studies of seed
rain and seedling demography for assessing recruitment.
Gause, George Francis
Gause's Principle: In competition between species that seek the same ecological
niche, one species survives while the other expires under a given set of
environmental conditions.
GIS
(Geographic Information Systems)
Geographic Information Systems (GIS)
are information management systems tied to geographic data. Various types
of data sets, such as hydrology, road networks, urban mapping, land cover, and
demographic data can contain hundreds of pieces of information about a specific
feature...all tied together geographically to provide spatial context.
Herbivores
Organisms that consume
only plant matter.
Impermeable
Layer
A layer of solid material, such as rock or clay,
which does not allow water to pass through. Coweeta is an ideal place to
study hydrologic processes, due to the underlying bedrock in the area.
Index of Biotic
Integrity (IBI)
A method of looking at
the quality of water and stream habitat using biotic inventories. Usually, the
total number of organisms and the number of different species present are
determined. Then these numbers are applied to an index, or scale, that lists
organisms according to their sensitivity to pollution.
Invertebrates
There are two basic
groups of higher animals. You've got your vertebrates and your INVERTEBRATES.
While both have become quite advanced through the process of evolution, there is
one fundamental difference. Invertebrates do not have backbones. Both groups are
in the Kingdom Animalia, but their bodies are organized differently. Some major
groups of invertebrates include: Protozoans - Very primitive, simple animals
like amoebas; Some of the Metazoa - Porifera (sponges), jellyfish, corals,
tapeworms, flukes, insects, arachnids, crustaceans, mollusks, echinoderms, etc.
Limnology
The sciences of freshwater. The word is derived from "limne"
(pool, marsh) and refers to the study of the ecology of inland waters. It is the
study of the relationships between the physical (ie. rocks or soils), chemical (ie.
ph of the water) and biotic (ie. living things such as plants) components in the
fresh water biotic communities. Limnology is a very broad field of study,
encompassing the sciences of biology, chemistry, geology, and physics as they
are applied to fresh water.
LTER (Long
Term Ecological Network)
The National Science Foundation
established the LTER program in 1980 to support research on long-term ecological
phenomena in the United States. The Coweeta LTER and the Georgia
Coastal Ecosystem LTER have the distinction of being the only two sites
in the network whose technology centers are housed in the same location (The
University of Georgia).
The mission of the LTER Network:
- Understanding ecological phenomena over long
temporal and large spatial scales
- Creating a legacy of well-designed and
documented long-term experiments and observations for future generations
- Conducting major synthetic and theoretical
efforts
- Providing information for the identification
and solution of ecological problems
To learn more, visit the LTER
Network Web Server...
Macroinvertebrates
Large organism without a spinal column. Insects,
crayfish, and worms are examples of macroinvertebrates.
Macrofauna
Macroscopic
Designating a size scale
very much larger than that of atoms and molecules.
Mean
The mean of a collection of numbers
is otherwise known as an average. This is computed by adding the collection of
numbers up and dividing by the total numbers in the collection (eg. 3+4+2=9,
then because there was 3 numbers in the collection, you divide the sum by 3. 9
divided by 3 = 3. Three is the mean.
Metadata
Metadata
is a component of data which describes the data. It is "data about
data." Metadata describes the content, quality, condition, and other
characteristics of data. Without proper documentation a data set is
incomplete.
Why Is Metadata a Vital Component of a Data
Set? Documenting data is critical to preserving its usefulness throughout
time. This documentation, or metadata, serves several functions. For instance,
metadata records important information on how the data were collected and/or
processed. Metadata is frequently utilized as a record in search systems so that
users can locate data sets of interest. In the future, analytic tools will
assess metadata to determine whether one data set can be properly compared or
processed with another.
Metapopulation Dynamics
Populations of many species occupy patches of high quality
habitat and use the neighboring habitat only for movement from one patch to
another. These species exist in a number of populations that are either isolated
from one another or have limited exchange of individuals. Such a collection of
interacting populations of the same species is called a metapopulation. Each
distinct population in a metapopulation may be referred to as a subpopulation, a
local population, or simply as a population.
National Science
Foundation
Long-Term Ecological Research is a program sponsored by the
National Science Foundation's Division of Environmental Biology (DEB Web
Server). A major force in the United States' commitment to research,
the National Science Foundation's mission
and history may
be of interest. The National Science
Foundation Web Server...
A program sponsored by the National Science
Foundation, the Division of
Environmental Biology (DEB) supports
fundamental research on the origins, functions, relationships, interactions, and
evolutionary history of populations, species, communities, and ecosystems.
Scientific emphases include biodiversity, molecular genetic and genomic
evolution, mesoscale ecology, conservation biology, global change, and
restoration ecology.
Oribatid
Arthropods can be found in all temperate
forest ecosystems in leaf litter. 95% of these are normally mites and
colembollas. Oribatid mites are the most abundant group with the highest numbers
found in forested ecosystems. Examples of a few other soil invertebrates are
springtails, mites, fly larvae, beetles, ants, and spiders. Oribatid mites are
the most numerically abundant group in most forested ecosystems and often
compromise about 50% of the total microarthropod fauna.
Ozone
O3, a triatomic form of oxygen; a
pungent, unstable blue gas that in the upper atmosphere forms a protective layer
against excess ultraviolet radiation, and is also an ingredient of photochemical
smog in the lower atmosphere; it is used in purification of drinking water and
as an oxidizing agent.
Paleo
The earliest time period from 8000 to
12,000 years ago and beyond.
Paleoecology
Paleoecology is the science of
reconstructing past environments using fossil materials of plants, animals, or
other indicators of past environments.
Park, Thomas
Waste accumulation and other stress factors can limit population growth..
Classic experiments by R. N. Chapman and by Thomas Park on flour beetles (Tribolium
confusum) proved that environmental stresses can limit population density.
Park demonstrated that male flour beetles release the pheromone ethylquinone
when another beetle interrupts them during mating. Park showed that the presence
of ethylquinone inhibits egg laying by flour beetles.
Pathogens
Any virus, microorganism, or other substance that causes disease; an infecting
agent.
Pleistocene
The most recent ice age whose time period spanned
from 1.8 million to 11,000 years ago. This is the time in earth’s history that
humans evolved and spread throughout most of the world. Pleistocene fossils are
often abundant, well-preserved, and can be dated very precisely. These fossils
allow scientists to determine dramatic shifts in climates and temperatures. For
more information and graphics on ice ages: http://www.hartwick.edu/geology/work/VFT-so-far/glaciers/glacier1.html
Predators
An animal that kills other animals for
food or any organism that kills and consumes other organisms.
Premature Senescence
A productive form of aging leading to organ/plant
death. Plants age productively; as tissues senesce they produce enzymes
necessary to recycle "expensive" materials and reroute the subunits to areas for
use by active growth elsewhere, in the next season, or by the next generation.
Premature senescence is when the plant or organ ages when it is suppose to. An
example is the vegetable and fruit industry is interested in extending the
post-harvest shelf life of produce in the market. This job is difficult,
because any chemical treatments used to prevent senescence must be safe for
human consumption. Apples are harvested before natural senescence, are cooled
immediately to slow respiration, and the storage chamber air is passed
continuously through charcoal to absorb any ethylene produced by a ripening
apple. Because ethylene is the starting hormone signal, one ripening apple will
cause those around it to also ripen. One bad apple spoils the whole barrel .
Productivity
The rate of output per unit of input.
Reference Experiments
Or called
"control". A unit that is representative of the true state of the ecosystem or
what is being tested.
Regionalization
Research at Coweeta LTER
Socioeconomic research in our southern Appalachian regionalization study area
has quantified both the past (1950s) and current land use patterns for selected
study areas. These Geographic Information System (GIS) layers are the bases for
both anthropological and economic studies to determine the causes and
consequences of observed land use patterns and changes over time. In addition,
our socioeconomic studies are predicting land use patterns for the year 2030,
which will provide likely future scenarios depicting the consequences of present
patterns of population growth and land use change. Current trends indicate that
the largest land use shift is from marginal agricultural land back to
successional forested areas, but increased home construction is causing the
forested areas to become more fragmented.
Riparian Research at
Coweeta LTER
The exchange of water, sediment, carbon, and nutrients between terrestrial and
aquatic ecosystems is regulated by riparian zones. More than 73 km of upland
streams exist in the 2185 ha of forest at Coweeta Hydrologic Laboratory.
Therefore, riparian zones constitute a large proportion of the landscape. Most
riparian zones in these forested areas are dominated by Rhododendron maximum, an
evergreen shrub. This keystone species (i.e., it has a greater role than its
coverage would suggest) is slow growing, but has increased in coverage since
fire suppression began in the 1920s. To determine the effect of Rhododendron in
riparian areas, soilwater, groundwater, nutrients, and litter fluxes are being
quantified in areas where Rhododendron has been removed, and compared to
untreated control areas during a multi-year study.
Riparian Zone
Riparian zones are areas of transition
between aquatic and upland ecosystems. These aquatic environments may be
streams, rivers, bogs, or lakes. Coweeta research focuses on the riparian
zones between streams and upland forest. The word riparian is derived from
the Latin word ripa, which means bank.
Sampling Frame
Defining a
set point in time and space which information has been gathered.
Scraper
Functional Feeding Group: Feed on algae and other
organisms attached to the surfaces of under water objects such as leaves,
sticks, or rocks.
Click here for a
picture.
Secondary Growth
A forest that has previously been cut and has
returned to forest.
Sediment
Suspended particles of organic matter (ie.dirt
from erosion) in water. It is a growing problem with our streams and rivers with
increased erosion from land practices.
Seine Net
Used to sample fish in shallow ponds or streams. A wide net that reaches from
top to bottom of the water and is pulled at each end; used to sweep across a
shallow body of water and capture fish.
Shredder
Functional Feeding Group: Consume coarse
particulate organic matter (CPOM), primarily live or dead plant materials
Click here for a
picture.
Spatially Explicit Model
A model that uses geographic information as its
data (constructed with spatial information).
Spatial Variation
The
variation that occurs based on location.
Species Composition
The types of species that are present in
an observed unit.
Stratigraphic Data
Data that addresses geology and the
layering of rocks and sediments.
Stream Habitats
riffle run pool
Stream
Biomonitoring
The use of
organisms living in the aquatic system as a measure of water quality.
Succession
Succession involves the changes that
occur in communities over time. Specifically,
the presence of specific species may provide an environment that is conducive to
the influx of other species. In the southern United States, pine trees,
due to the local environment they provide, are normally considered the
precursors to hardwood trees. Note that, while succession is a considered
a valid model for predicting change in an ecosystem, many factors (human
intervention and weather related events, for example) can interrupt the
successional cycle.
Temporal
Variation
Variation that occurs for a defined period of time.
Temporary variation.
Topographic
What is on the surface of the earth such as elevations
or landforms.
Terrestrial Ecosystems
A
dynamic complex of plant, animal and micro-organism communities and their
non-living environment interacting as a functional unit on land.
Terrestrial Research
at Coweeta LTER
Terrestrial research is organized across the landscape with elevations ranging
from 678 to 1592 m along the complex environmental gradients created by abiotic
factors including elevation, aspect, precipitation, and temperature. Terrestrial
processes including productivity, decomposition, soil nitrogen mineralization,
photosynthesis, respiration, herbivory, seed rain, and seedling demography are
quantified along this gradient. This gradient approach allows the functional
relationships between variables to be defined and also allows the variables to
be extrapolated to the larger landscape of the southern Appalachians.
Type 1 Data
...includes data routinely collected by
staff, Co-PIs or associated investigators supported financially or in-kin by NSF
LTER funds and crucial to multiple research projects. This includes
climatological, hydrological and similar data. These data sets are
available to all interested parties with few or no restrictions other than those
stipulated in the DATA USERS AGREEMENT. Such data must be uploaded to the
Coweeta website and made available within three years of finishing the data
collection. Type 2 data sets are automatically migrated to Type 1 status
after three years have elapsed from the completion of a project.
Type 2 Data
...includes original data collected by
staff, Co-PIs, or associated investigators supported financially or in-kind by
NSF LTER funds. Type 2 data are available only with written permission
from the Co-PIs directing this segment of LTER research. The purpose is to
ensure that data being requested are appropriate for the purposes stated, and
that the PI has sufficient time to process, analyze, synthesize, and publish
results. Data sets of Type 2 status will be maintained for a maximum of
three years after completion of the project, at which time they will be migrated
to Type 1 status.
Vegetation
composition
The types of vegetation that are present in an area.
Watershed
A watershed consists of all the land
and waterways that drain into the same body of water. Smaller watersheds
join with other watersheds to drain into larger watersheds; thousands of smaller
watersheds drain into large rivers like the Mississippi or Colorado
rivers. Coweeta was an ideal place to site a hydrologic lab because the
area contains many sub-watersheds, allowing scientists to carry on numerous
research projects without fear of contamination from adjacent projects.
An excellent primer on watersheds,
including a utility that allows you to find the
watershed where you reside.
Weir
Weirs are concrete basins sited on
streams that measure stream and stormflow by a water level recorder. Scientists
at Coweeta also take weekly samples for chemical analysis. They can see the
effects of any land disturbance, storm, insect infestation, etc. Any water that
is not absorbed by the vegetation or the soil ends up running through the
weir. The location for the lab was originally chosen in the Coweeta Valley
basin because of it's unique sub-watersheds, high rainfall, and tight impermeable
bedrock.
Windthrow
Trees uprooted by excessive wind.
Shallow-rooted trees are almost always affected.
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