Aliens!!!

Introduced species Non-native species kudzu transplanted populations grow exponentially in new area out-compete native species loss of natural controls lack of predators, parasites, competitors reduce diversity examples African honeybee gypsy moth zebra mussel purple loosestrife FIRE ANTS! gypsy moth kudzu

Solenopsis invicta Originally from Argentina and Brazil Believed to have been introduced to the US in the 1930’s http://www.youtube.com/watch?v=2bdry7_5qck Outcompete native species, aggressive. Spread limited by freeze in northern states http://www.livescience.com/12985-fire-ant-invasion-solenopsis-invicta-pest.html

Biological controls Phorid fly! http://www.youtube.com/watch?v=UiJgsPUYahs Research paper

Why should we study invasive species? Understanding behavior, density and distribution is essential to designing effective control measures.

ecological study Involves Planning: Design (research question) Logistics (field work) Analysis (statistical) You need samples

What is a sample? “A portion, piece, or segment that is representative of a whole”

Why do we sample? Because it is usually impossible to know all the plants or animals present in a given area # insect larvae in a pond # coral colonies on a reef # trees on a river terrace # of ants in a field

Why do we sample? or measure every value of a parameter e.g. dissolved nutrients in tide pools e.g. sorting of sand grains on beaches e.g. species along an exposure gradient e.g. plant cover on backshore beaches

NON-INVASIVE SAMPLING Avoid any degradation of the habitat when sampling Removal of whole or parts of organisms should be limited to species that can quickly recover

REPRESENTATIVE SAMPLING Take a number of samples from around the sampling site so as to be reasonably sure that the samples represent the site in general

Necessities… For the samples to represent the whole it is necessary to: take appropriate samples take enough samples avoid bias when sampling

SAMPLING UNITS The type of sample unit is determined by the organisms and the physical nature of the habitat being sampled Volume of water, air, or soil Area of ground surface

Regular Units Standard units enable comparison of results Spatial Temporal

Bottles Provide a standard, volume sampling unit

Nets Also provide a standard, volume sampling unit

Cores Provide a standard, volume sampling unit

QUADRATS Provide a standard, area sampling unit eg. square frame Consistent size and shape is essential for comparing samples from different places and/or times

Quadrat Size Chosen to suit sampling goals A balance between what is best and what is practical is always necessary Should suit: habitat organism practical constraints

Habitat size Appropriate sample unit size and numbers depend on size scale of the habitat Small scale habitats require smaller sized samples Ex. Boulders Large scale habitats require larger sized samples Ex. Forests

Transect sampling Transects are often set up along environmental gradients down a hillside across a streambed out from a source of pollution You can measure at regular intervals or at random intervals

transect undisturbed disturbed

Quadrat sampling

RANDOM SAMPLING Often used when the area being studied is fairly uniform, very large, or when there is a limited amount of time available Random = chosen by chance rather than according to a plan; all outcomes are equally likely

Haphazard Sampling Choose individuals or place “sampling units” arbitrarily This is rarely completely random OR…

How to sample randomly Samples are taken from different positions within a habitat and those positions are chosen randomly Assign numbers to the areas or individuals to be sampled Use a random number table to select which areas or individuals will be sampled

quadrat

Handling of fire ants Basic Lab procedure

Identification of Ant species

IA Lab Prompt: Invasive Species Design an experiment to test the effect of an environmental factor on invasive species populations in Austin.