1.1-b) Sampling Animals and Plants

• Qualitative: ➞ is descriptive, and regards data that can be observed, but not measured. ↳ (used to inform on what species are present) • Quantative: ➞ regards information about quantities, and therefore numbers. ↳ (allows for statistical analysis and interpretation of trends)

• Sometimes a population is so large that it would be impractical to sample every individual. • In this case, a representative sample of the population is selected. • If a population has a wide range of variations, then a larger representative sample is needed.

• The sample should have the same mean as the population as a whole. • The sample should have the same degree of variation about the mean as the population as a whole. • The sample should be a large sample.

• Simple Random: ➞ each member of the population has an equal chance of being sampled ↳ (e.g. random quadrat sampling) • Systematic: ➞ members of a population are selected at regular intervals ↳ (e.g. sampling an ecosystem every 10 metres along a transect) • Stratified: ➞ the population is divided into categories and then sampled proportionally ↳ (e.g. sampling of three distinct habitats)

• It is important to identify and monitor species for several reasons: 1. monitoring population change 📉 2. monitoring invasive species ❗ 3. monitoring pollution using indicator species ☢️ 4. monitoring the discovery of new species ✨

• Indicator species can be used to determine the impact of pollution on an environment. ➞ The presence, absence or abundance of certain living organisms show if an environment is affected by a particular set of environmental conditions. ↳ (e.g. Lichens can tolerate different levels of atmospheric sulfur dioxide)

• Density: ➞ is the number of individuals of the same species pesent per unit area or unit volume.

• Relative abundance: ➞ is how common or rare a species is relative to other species in a defined area or community (expressed as a percentage of the total number of organisms in an area)

• Frequency: ➞ is the chance of finding a species within a defined area and the number of percentage of samples in which a particular species occurs ↳ (e.g. a quadrat)

• Percentage cover: ➞ is a measure of the amount of cover of a particular species in a quadrat.

• Distribution: ➞ is the manner in which a group is arranged geographically and can change seasonally, in response to resource availability and in response to other external factors.

• A transect is a sampling method which investigates the distribution of organisms in relation to a fixed area by recording all the species found at points, or in a quadrat placed in certain intervals along a line.

• Line: ➞ A line is drawn through the habitat. Any species touching the line is counted and recorded (e.g. a piece of string placed along a habitat and the number of dandelions touching the line can be counted). • Belt: ➞ A quadrat is placed continuously along a transect line of a known length and width (e.g. quadrats placed continuously along a line of a river bank). • Point: ➞ Sampling using simple, random, or systematic methods at known points along the transect line (e.g. quadrats placed every 10m along a transect line).

• Organisms in a quadrat may be wrongly identitified ➞ a.) use a resource (e.g. internet) to identify unknown organisms (+ paired statement keys, reverse imageing, photographs, etc) • Organisms in a quadrat may be wrongly counted ➞ b.) Establish a common rule for counting organisms (i.e. plants/organisms that are half in/out) • Sample may not be representative of the ecosystem ➞ c.) Take several samples and calculate an average (mean)

• The ‘capture-mark-recapture’ technique can be used to estimate the size of a population (invertebrates and vertebrates) • After random sampling has been carried out, the Lincoln Biodiversity Index can be used to determine an estimate of the total population. • A sample of the population is captured and marked (M) and released. • After an interval of time, a second sample is captured (C) ➞ (which allows the population to mix - to have an equal chance of all members of the population to be in the second sample) • The number of recaptures (R) in the second sample is counted. • The total populaton is found using the formula: ➞ Total population (N) = (M x C) /R

• INVASIVE: 1. Quadrats 2. Pitfall traps 3. Net sampling ➞ Sweep nets (insects) ➞ Mist nets (birds/bats) ➞ Drip nets (fish) 4. Capture-mark-recapture 5. Tree beating 6. Pooters • NON-INVASIVE: 1. Drones 2. Camera traps 3. Thermal cameras 4. Observational data 5. Audio recording 6. Motions sensor cameras 7. Faecal sampling 8. Hair trapping

• Biotic indice: ➞ is a scale showing the quality of an environment based on the types of organisms that inhabit it.

• Trent biotic index: ➞ a measure which uses freshwater invertebrates to compare water quality at different points in a stream or river. ↳ These species are indicator species, which give information regarding the quality of the environment based on their presence, absence, or abundance. • Scores range from 0 for highly polluted water to 15 for clean water.

• Simpson’s diversity index: ➞ a measure of diversity which takes into account the number of species present, plus the relative abundance of each species. • The value of D ranges from 0 to 1: ➞ 0 represents infinite diversity = better health of an ecosystem ➞ 1 represents no diversity = worse health of an ecosystem

• Validity: ➞ is the measure of how well a test measures what it is meant to measure (related to variables)

• Reliability: ➞ is the ability of an experimental design to give stable and consistent results (measure of consistency)

• Ensuring your variables are kept constant • Ensuring sampling time/location is kept the same • Using multiple sampling methods to confirm this trend (triangulation) • Comparing findings from your study to previous studies

• Taking more samples • Repeating the experiment • Using a larger number of pieces of sampling equipment (e.g. multiple bat detectors)