Measuring biotic components of a system Ecological Sampling Measuring biotic components of a system

Is the amount of different species found in different areas Is the amount of different species found in different areas. The more biodiversity, the more differences in species found. The most biodiverse area of the world are ecosystems on and near the equator. Biodiversity is key to having life continue under many different circumstances.

Ecological Sampling What is a sample? “A portion, piece, or segment that is representative of a whole” Why do we sample? it is usually impossible to measure the whole https://www.youtube.com/watch?v=HLX76gdXgTA (4 min)

One big assumption… That the sample is representative of the whole It is necessary to take enough samples so that an accurate representation is obtained It is important to avoid bias when sampling

Sampling Methods Transects and Quadrants Lincoln Index Plants and Non-motile animals Lincoln Index Capture –Mark- Recapture Small animals Aerial observations Large trees and animals

Measuring ecosystems Scientists use many methods to study these interactions/ecosystems. Observation is a vital tool. Direct surveys = watch animals with their own eyes and see how they interact Indirect surveys = check for signs of animals and try to guess interactions For plants we use quadrat sampling. Check a small sample area and calculate larger number

Ecological Techniques A variety of universal practical approaches exist for investigating the biotic and abiotic components of ecosystems Field ecologists investigate communities by using random sampling techniques that aim to: eliminate bias reduce the effects of chance minimise errors in obtaining measurements/samples Quadrat and transect sampling are commonly used methods for investigating distribution within plant communities and the more sedentary populations of animals such as those found inhabiting seashores

Frame quadrats are wooden or metal frames of known area (e.g. 0.25 m2, 0.5 m2, 1.0 m2) and are generally square-shaped Various approaches are used to determine the representation of species within an area: Species population density (number of individuals per square metre) is determined by counting all individuals within a series of randomly placed quadrat frames and calculating the mean Percentage cover is determined subjectively by assessing the extent to which different species occupy subdivided quadrat frames or by the use of point quadrat frames Frequency of occurrence of a species is determined using subdivided quadrats and point quadrat frames

Quadrat sampling is a classic tool for the study of ecology, especially biodiversity. In general, a series of squares (quadrats) of a set size are placed in a habitat of interest and the species within those quadrats are identified and recorded.

Simply throw the grid out and find an average number of organisms with some basic math.

Quadrat sampling involves counting all individuals within a known area (or volume). Since density (D) and population size (N) are related, as N = D x area, we can estimate the density for the sample and from this compute the total population. ... Instead, we can calculate the average of these samples.

Quadrats and Population Size Friday Field Lab Page 401 of textbook— Quadrats and Population Size T= N/A T=total population estimate N=#of individuals counted # of quadrats A= total area area of quadrat

Dress in Layers Estimated temperature at time of class in mid 40s-50s degrees

Bio Blitz Dance https://www.youtube.com/watch?v=rgn6QU-P0wI

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