Term
| (scientific method) Inductive Reasoning |
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Definition
| The process of using observations to reach a general conclusion. |
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Term
| (scientific method) Deductive Reasoning |
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Definition
| The process of using general conclusions or principles to generate specific predictions. |
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Term
| (scientific method) Continuous Variable |
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Definition
A variable that can theoretically take on an infinite range of values
Ex: the size, length, and mass of an organism. These values are simply limited by the resolution of the instruments in use. |
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Term
| (scientific method) Discrete Variable |
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Definition
| A variable we measure by counting its property or by counting the number of times a given event occurs |
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Term
| (scientific method) Categorical Variable |
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Definition
A type of discrete variable. One that has two or more categories, but where there is no intrinsic order to the categories.
Ex: Hair color, gender |
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Term
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Definition
| An explanation for a scientific observation. NOT a prediction. |
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Term
| If.... Then.... Statements |
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Definition
| If..hypothesis..Then..prediction. |
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Term
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Definition
| A statistical hypothesis that predicts that there will be no difference between populations, or not relationship between two variables. |
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Term
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Definition
| also called the average, this is the "measure of central tendency." The mean is calculated by adding up all values of a particular observation and dividing this sum by the number of observations. |
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Term
| (descriptive stats) Median |
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Definition
| The value between all values. |
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Term
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Definition
| The value that occurs most frequently. |
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Term
| (descriptive stats) Variance |
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Definition
| S2.A measure of the dispersion of observations around the mean. Defined as the sum of the squared deviation from the mean value, divided by the sample size minus 1. |
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Term
| (descriptive stats) Standard Deviation |
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Definition
| The square root of the variance and it reflects the degree to which a single observation typically deviates from the mean. Usually, any data more than 2 standard deviations away from the mean signifies that those data sets are outside of the norm for that population. |
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Term
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Definition
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Term
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Definition
| This value describes how well the data points fit the line. If this value equals 1.0, then the line is a perfect fit. |
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Term
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Definition
| compares 2 means to see if measured differences are statistically different. |
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Term
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Definition
comparison between calculated t-value and critical t-value.
calculated t-value > critical t-value, p < 0.05: means of two samples are significantly different
calculated t-value < critical t-value, p > 0.05: means of the two samples are NOT significantly different. |
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Term
| (t-test) 1 tail vs. 2 tail |
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Definition
| the basic difference between the two-tailed and one-tailed t-test is in the cut-off for the critical t-value. The probability of rejecting the null hypothesis for a one-tailed t-test occurs at a smaller critical t-value than for a two-tailed t-test. |
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Term
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Definition
| Determines if frequency of observations are different between two samples |
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Term
| (chi-square test) P-critical vs. P-calculated |
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Definition
| In order to determine whether or not to reject the null hypothesis, you have to compare your P-calculated value to the P-critical values which are determined by different degrees of freedom. |
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Term
| (Ponderosa Pine Lab) What is the Life Zone concept? |
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Definition
| Areas that share similar climatic variables; understanding that similar climatic variables are associated with plants that share similar adaptations. |
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Term
| (Ponderosa Pine Lab) How does elevation effect growing conditions? |
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Definition
Elevations is roughly correlated with with average yearly temperature and rainfall. Elevation is also related to the length of the growing season, wind speed, light exposure, and soil compaction.
As elevation increases, the growing season shortens and wind speed, light exposure, and soil compaction increase. |
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Term
| (Ponderosa Pine Lab) How did we measure the height of trees? |
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Definition
| We used a clinometer to measure the height of the tree. |
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Term
| (Ponderosa Pine Lab) How did we determine the diameter of trees? |
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Definition
| We used DBH Tape to determine the diameter of the trees. This tape is made especially to measure diameter. |
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Term
| (Ponderosa Pine Lab) What test did we use to look at the trend of growth rate at different elevations? |
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Definition
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Term
| (Ponderosa Pine Lab) What test did we use to compare the height of Ponderosa Pines and their nearest non-Ponderosa neighbor? |
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Definition
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Term
| (Isle Royale) Exponential Population Growth Model |
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Definition
This model assumes that the population is increasing at its maximum per capita rate of growth.
dN/dt=rN |
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Term
| (Isle Royale) Logistic Population Growth |
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Definition
In this model, the per capita growth rate (r) decreases as the population density increases. When the population is at its carrying capacity (N=K) the population will no longer grow.
dN/dt=rmaxN[(K-N)/K] |
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Term
| (Isle Royale) Carrying Capacity |
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Definition
| Symbolized as K. This is the maximum number of individuals of a particular species that the local environment can support at a particular time. |
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Term
| (The Stream Assessment Lab) Species Richness |
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Definition
| the total number of species within a habitat or community. It does NOT provide any information on how well each species is represented. |
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Term
| (The Stream Assessment Lab) Species Diversity |
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Definition
| a measure of both the number of species (species richness) and the relative contribution each of these species to the total number of individuals in a community (evenness). |
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Term
| (The Stream Assessment Lab) Shannon-Weiner Index |
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Definition
Takes both species richness and relative abundanceof each of these species in a community into account to determine the uncertainty that an idividual picked at random will be a given species.
H': represents the uncertainty of picking a particular species. When H'=0 there is only 1 species present, as so there is no uncertainty as to what species each individual will be. When H'=4 there is relatively high uncertainty because species are relatively evenly distributed. |
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Term
| (The Stream Assessment Lab) Jaccards Index |
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Definition
Allows us to quantify the degree of overlap between species in two communities.
JI=A/(A+B+C)
A= total number of species present in both communities
B= the number of species present in community 1 but not 2
C= the number of species present in community 2 but not 1 |
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Term
| (The Stream Assessment Lab) EstimateS |
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Definition
Allows the researcher to determine both how well they have sampled a habitat and, given the collecting data, to also estimate the number of species that should be present in the habitat.
Sobs= # of species observed
estimator models= measures ratio of uniques to duplicates found within the pooled sample.
You know when you are done sampling when you find most of the species your estimators predict. |
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Term
| (The Stream Assessment Lab) Stream Quality Index Score |
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Definition
This is the process of using the presence of absence of species to determine the health of the stream. The basic premise is that some speices are more tolerant of pollution and environmental stress than others.
Stream Quality Index is calculated by multiplying the number of species found in a certain taxa by their particular value (1 being pollutant-tolerant and 4 being the most sensitive). You then sum the total value and then divide the total by the total number of taxa that you found.
How healthy is a stream:
3.6+......very healthy
2.6-3.5...good
2.1-2.5...fair
1.0-2.0...poor |
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Term
| (Intermediate Disturbance Hypothesis Lab) What does the intermediate disturbance hypothesis say? How did we test it? |
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Definition
This hypothesis states that intermediate levels of disturbance will lead ot the greatest species diversity: in low-disturbance environments a small number of competitively dominant species will take over; in high-disturbance environments only species that tolerate disturbance will survive.
see page 88 for equation
Simpson's index uses the population size of each species in the study area to generate a single number indicating diversity. |
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Term
| (Intermediate Disturbance Hypothesis Lab) What does Simpson's Diversity index measure? What do the different values indicate? |
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Definition
Simpson's Diversity Index measures the diversity in the study area. A low number indicates low diversity (1 is the minimum) and and high number indicates greater diversity.
D=diversity
S=number of species
pi= the population size of species i divided by the total population size of all species. |
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Term
| (Estimating Life History Tables Lab) Survivorship Curves |
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Definition
Type I: (convex) this is for species that have a high survival rate of the young. Most live out most of their lives and die in old age.
Type II: (linear) this is for species who have a relatively constant death rate throughout their life span.
Type III: (concave) this is for species that have many young, most of which die very early in their life. |
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Term
| (Estimating Life History Tables Lab) What is a life table? |
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Definition
| One way of summarizing key demographic variables, including survivorship, age- and gender-specific mortality rates, and expectations of further life. |
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Term
| (Estimating Life History Tables Lab) What is the difference between static and dynamic life tables? |
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Definition
A static life table gathers information based on age at death to estimate mortality rates and to calculate other vital statistics for the study population. Entries are age-specific and made up of individuals who started life at different times.
A dynamic life table follows a cohort of organisms from birth, recording the age at which each individual dies, until all individuals of the original cohort have died. |
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Term
| (Estimating Life History Tables Lab) What is a cohort? |
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Definition
| A cohort is all members of a particular age class. |
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Term
| (Estimating Life History Tables Lab) What is a mortality curve? |
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Definition
| A mortality curve is the inverse of a survivorship curve. |
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Term
| (Prairie Dog Lab) What is a keystone species? |
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Definition
| A keystone species is an animal whose removal from a particular food web could result in a collapse of that food web. An animal that plays a key role in the ecosystem. In this case, prairie dogs serve as prey for many predators on the prairie. |
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Term
| (Prairie Dog Lab) What is an ecosystem engineer? |
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Definition
| Organisms who have a disproportionately large effecton their particular ecosystems. |
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Term
| (Prairie Dog Lab) What is the rescue effect? |
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Definition
| This refers to the reduced probability of population extinction due to immigration. |
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Term
| (Prairie Dog Lab) What is the refuge effect? |
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Definition
| Boundedness may create a refuge effect for a colony of prairie dogs because they are isolated from their natural predators. Therefore, the population size may increase. |
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Term
| (Prairie Dog Lab) Burrow Density Dispersion |
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Definition
| The number and pattern of prairie dog burrows per unit area. Burrows can be clumped, random, or uniform. |
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Term
| Dispersion statistics: what is indicated if Tcalculated > Tcritical? What does v/m indicate? |
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Definition
If Tcalculated > Tcritical then the null hypothesis is rejected and there is a clumped dispersion pattern.
v/m indicates variance/mean ratio |
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Term
| (Prairie Dog Lab) What is boundedness? |
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Definition
| Boundedness describes the immediate surroundings of a local population and is based on the amount of unsuitable habitait surrounding it. |
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Term
| (Prairie Dog Lab) What is a meta population? |
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Definition
| A set of local populations within some larger area, where migration from one local population to at least some other patches may be possible |
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Term
| (Prairie Dog Lab) What is a local population? |
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Definition
| Sometimes called "demes", these are defined as a set of individuals that live in the same habitat patch and interact with each other. |
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Term
| (Conservation Biology) Define Genetic Diversity |
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Definition
| Refers to both individual variation within a population and variation between populations |
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Term
| (Conservation Biology) Define Species Diversity |
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Definition
| Refers to the variety of species in a particular region. |
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Term
| (Conservation Biology) Define Ecosystem Diversity |
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Definition
| Refers to the variety of earth's ecosystems. |
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Term
| (Conservation Biology) Small-population approach |
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Definition
| Taken into consideration when determining whether a species should be protected under the ESA. Here, the population size is looked at. |
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Term
| (Conservation Biology) Declining population approach |
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Definition
| Taken into consideration when determining whether a species should be protected under the ESA. Here, the population dynamics are looked at. |
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Term
| (Conservation Biology) SLOSS |
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Definition
| One way to increase critical habitat for a species. Here, one is deciding between Single Large OR Several Small preserves. |
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