elenges in terms of sampling them quantitatively to estimate (below), to more complex electronic devices, such as those usede plants, most animals are highly mobile and present special sampling animals ranges from various types of nets and trapsdistribution and abundance. The equipment available forPlankton netTow ropeBridleKick samplingDirectionof currentPooter (aspirator)Glass collectingtube that sucksup small animalsMetal hoopSpecimentubeCanvas sleeveRocks upstreamof the net aredisturbedCone ofbolting silkPlastic containerfor collectingplankton sampleDirectionof current.Rubber orcork bung2007-2013 BIOZONE InternationalISBN: 978-1-927173-55-8Photocopying ProhibitedTie cordSmall aquaticInvertebrates aredislodged andcollect in the netGauzecoveringopening oftubeClearplastictubeGlass mouthpiece throughwhich operator sucksBeating trayTullgren funnelPitfall trapGround slopesaway from trap toassist drainageJam jar sunkinto ground2. Explain why pitfall traps are not recommended for estimates of population density:3. (a) Explain how mesh size could influence the sampling efficiency of a plankton net:(b) Explain how this would affect your choice of mesh size when sampling animals in a pond:Tree branch isshaken or beatenwith a stickInsects and otherinvertebrates fallFlat rockCanvas stretchedover frame.Light from a battery operatedlamp drives the invertebratesdown through the soil or litter.Large diameter funnelcontaining soil or leaf litterresting on a gauze platform.Gauze allows invertebratesof a certain size to movedown the funnel.Collecting jar traps theinvertebrates that fallthrough the gauze andprevents their escape.1. Describe which of the sampling techniques pictured above provides the best quantitative method for samplinginvertebrates in vegetation. Explain your answer:Support madeof small stonesor sticks3 cm of water or50% ethanolmay be addedas immobiliserRelated activities: Mark & Recapture Sampling, Sampling a LeafLitter PopulationInvestigating EcosystemsRA 2

Planktons are microscopic organisms that float freely in bodies of water such as freshwater lakes, streams, and the ocean. Plankton is made up of microscopic algae plants (called "phytoplankton") and microscopic animals (called "zooplankton"). Plankton is derived from the Greek word "planktos," which means "drifting." Plankton is the first link in the aquatic food chain, and it is consumed by a wide range of organisms, including clams, mussels, fish, and mammals such as whales. Phytoplankton contributes significantly to the global Carbon Cycle by absorbing carbon dioxide from the atmosphere during the process of photosynthesis.1. The beating tray is the best quantitative method for sampling invertebrates in vegetation. This is due to the fact that if you take a sample from a single plant, you can estimate the population size by multiplying the number of invertebrates on that plant by the number of plants. There is also no prior interaction with the landscape with this type of test; in some of the other tests, man-made objects must be inserted into the environment before collecting can begin, and the invertebrates may choose to avoid that object.2. Pitfall traps are not recommended for population density estimates because the structure holding the rock up over the jar may collapse. Animals or invertebrates would not normally go under such conditions. Putting the jar in the ground requires prior disturbance of the area, which may scare them away.3. (a) Mesh size could influence the sampling efficiency of a plankton net because if the mesh size is too large, the smaller species of plankton could slip through the net and not be recorded and measured. (b) This would affect the choice of mesh size when sampling animals in the pond because choosing a small mesh size is more convenient so that we could catch all of the organisms within the pond, or at least the best majority. On the other hand, if someone is trying to catch only larger organisms, he or she would use a very large mesh size.