Glossary of terms relating to biodiversity and nature.
Resources for You
General term describing any bird that spends part of its life
in or near water, particularly swimming and diving birds and waders.
A plant that is in or on water throughout the entire growing
season. For the purposes of the Rideau River Biodiversity
Project, aquatic plants are defined as those growing in a half-metre
or more of water.
|
|
| Painted turtle (Chrysemys picta)
basking in the sun. |
Basking sites are spots such as rocks or fallen logs
where cold-blooded animals or "sunbathe" after eating a meal. Cold-blooded
animals such as turtles require the heat of the sun to increase their body temperature
in order to increase their metabolism rate, which helps them digest their food.
The Shannon-Wiener biodiversity index is a mathematical
formula used by biologists to describe the species diversity (number of species)
and abundance (number of specimens of each species) in a given area. [32]
Indices of different "subjects" cannot be compared.
(A "subject" could be a single species or an entire category of organism,
such as aquatic plants). Rather, it is possible to compare the status of a single
subject in different environments, or in one environment at different times.
The indices for the Project are calculated for categories
of organisms, and are presented according to four sections of the River.
Any given value on the biodiversity index does not necessarily
accord with an evaluation, such as poor, moderate or good. Such evaluation is
a subsequent interpretation. We have applied such evaluation to our biodiversity
index values in order to aid understanding of their significance, and to facilitate
appropriate comparison of different "subjects" in a given section
of the River. For example, it would not be appropriate to assume that because
the index value for mussels is lower than that of fish, that the situation for
mussels is worse than that for fish; because the number of mussel species in
a river will naturally be smaller than the number of fish species, it is normal
for the index value for mussels to be lower than that for fish.
It should be noted that exotic species have not been
included in the calculation of the indices except in the case of aquatic plants,
where it was sometimes difficult to determine which were indigenous species and
which were exotic.
An organism that feeds on animal flesh.
A living organism that feeds on dead, or waste, organic
material (e.g., corpses, excrement). [30]
Period in which the metabolic activity or development
of an insect is dormant at a certain stage (egg, larva, nymph or adult) of its
maturity, because of the action of internal or external factors. [30]
Diatoms are living organisms, but are neither animal
nor plant. Like plants, however, diatoms contain chlorophyll and produce their
own energy. Each diatom is a single cell, and is encased in silica. This shell
is like a shoebox, with a bottom and a slightly larger top.
A group of organisms and their interactions with their
surrounding environment.
A plant the greater part of which, including the leaves,
floats on the surface of the water, although its roots are under water. Example:
pickerelweed.
The process in which an organism burrows into the flesh
or gills of a host for protection and nourishment. For example, in their larval
stage, freshwater mussels attach to fish gills and use the fish tissue as an energy
source to complete development. They stay there for a varying number of weeks,
depending on the species. Once the juvenile mussels have developed enough to survive
on their own, they drop off the fish gills and settle on the river bottom to grow
into adults.
|
|
| This shoreline has been eroded by the wakes
of passing boats. |
The removal or washing away of soil and rock particles
by the action of wind or running water.
A species that is found outside of its normal area
of distribution. [31]
This term may apply to a species that originated in another region, province or
country. For example, the bullfrog, which is native to eastern Canada, is an introduced
species in British Columbia.
The entire plant, or most of it, especially the leaves,
floats on the surface of the water. Example: yellow
pond lily.
Respiratory organs in aquatic animals. [30]
|
|
| Glochidia of a floater (Pyganodon
sp.), seen through a microscope. |
When freshwater mussels are in their larval stage,
they are called glochidia. They are released from the female mussel then attach
themselves to the gills of fish where they develop until they are able to survive
on their own.
An organism that feeds on vegetable matter.
It is impossible to measure everything in an ecosystem,
so scientists select representative plants or animals. Through monitoring, these
indicator species provide clues to changes in the health of an ecosystem. Species
that respond quickly and dramatically to environmental change give biologists
an early warning of possible problems.
An organism that feeds on insects.
An exotic species that flourishes in its adopted ecosystem
(or natural or semi-natural habitat) to the extent that it successfully competes
with native species, thereby threatening the natural biodiversity. [31]
A young animal that has not yet attained sexual maturity.
Nutrients are elements that can be assimilated by an
organism without there being any digestive function. [30]
A distinction is made between macronutrients, which an organism needs in large
quantities, and micronutrients, which an organism consumes only in minute quantities.
Macronutrients include calcium, phosphorus and nitrogen. Micronutrients include
copper, zinc and manganese.
A gathering point along a migratory route where birds
stop to feed, rest and moult. Birds moult at the end of the summer or the beginning
of the autumn, depending on the species. During moulting sessions, until their
new plumage grows in, birds are not able to fly very far. Wetlands are often used
as staging areas because high quality food and shelter are close by.
A species naturally found living in an area, without
having been introduced.
An organism that feeds on a variety of substances,
whether animal or vegetable.
Sediment is made of particles of earth from sources
such as clay, topsoil or sand. Sediment can originate with agricultural irrigation,
destruction of the riverbanks, or any other cause. Sedimentation in a river or
other watercourse is said to occur when it has excessive quantities of sediment.
Such sediment ultimately covers the bottom of the watercourse and can suffocate
the aquatic organisms that live there.
Most or all of the plant, including the leaves, grows
under the water. Example: tape
grass.
A morphologically distinct subdivision of a species
that predominates in a defined region of the area occupied by the species and
is rarely found outside of that region. [30]
The term "terrestrial plant" covers a vast
range that includes not only plants that grow on land but also water (aquatic)
plants, as these are land (terrestrial) plants whose evolution brought them to
an aquatic environment.
Division of species into groups on the basis of diet
(carnivore, herbivore, etc.).
The clouding of water that is caused by tiny particles
of eroded soil and rock that remain suspended in the water column.
The natural geographical region drained by one or more
watercourses and their tributaries. [30]
Breadth of a bird's wings when fully extended.
