BIOL 228 Lab Quiz Flashcards
Define: Biotic Potential
The characteristic of all populations to produce more individuals than are required to replace those already existing. Biotic potential defines the maximum rate at which a population will grow if
conditions are ideal.
What are the four factors in female life history that determine biotic potential
- The length of time a female reproduces.
- Female age specific survivourship.
- Female births per female per reproduction.
- Delay of reproduction; the time between birth and production of the average number of female
offspring (the generation time T).
Define carrying capacity
the maximum number of individuals the environment can support
Do you know what a exponential vs logistic growth graph look like?
pretty sure I do yeah
Define Flora
Although sometimes used to refer to plants in general, a flora is a list of plant species that occur in a given area where the order of species is related to ease of use. Often the flora for a given area will be arranged in alphabetical order by scientific name.
Define Vegetation
A vegetation is a list of plant species that occur in a given area where the order of species is related to importance or abundance of each species present
Define density
The term density refers to the number of individuals per unit area usually obtained by a simple count of plants in a series of random quadrats
Define Transects
A series of straight lines, either parallel or perpendicular (produces a grid system) to one another, in the study area.
Define Quadrats
Sample reference frames of
known area are then placed along the transects and data is gathered within the frame.
Define Areal Cover
Areal cover can be defined as the vertical
projection of the above-ground parts of each plant onto the ground.
In some circumstances it is the leaf projection that is measured; in others, the area at the base of the plant.
In distinctly layered communities each layer must be considered separately; thus the shrubs are measured by
their crown spread and the herbaceous plants comprising the understory by their leaf spread or their basal area.
In dense sod-forming pastures leaf spread is the criterion because it is impossible to distinguish the basal areas of individual plants.
In trees basal area is measured through the diameter, usually at breast height (abbreviated as dbh in forestry literature), 1.5 m above the ground.
Define the Leaf Area Index (LAI)
The ratio between the total leaf area above the soil surface and the soil surface area.
As there can be more than one layer of leaf material over the same soil surface LAI can range from close to 0 in true
desert to almost 5 in tropical rainforest
Define Photosynthetically Active Radiation (PAR)
The amount of photosynthetic radiation that is available to plants, trees get more than shrubs
Explain Frequency
Frequency relates to the number of times a species occurs in a given number of repeatedly placed small sample plots or sample points.
For comparing different communities, frequency is best expressed as a percentage of the total number of placements, i.e., the frequency percentage or frequency index
Frequency provides an objective assessment, but it is a non-absolute measure. This means that the
result is, in part, a function of the size and shape of the quadrat frame. Results, therefore, have meaning only concerning a particular frame size and shape selected for a determination
Two types of frequency are used: shoot frequency, obtained by recording as present all foliage overlapping into a quadrat, and rooted frequency, which records a species being present only
when it is rooted in the quadrat.
Define and explain: Biomass
Biomass refers to the total dry weight of biological material per unit area and is usually obtained by harvesting plants in a series of random quadrats. These plants are then dried at 60o C until a constant dry weight is achieved.
Do you know the random dispersion curve?
yes it looks kinda like a logistic curve
