Resilience and Diversity in a Kelp Forest

Transcription

1 Resilience and Diversity in a Kelp Forest Nicole LaRoche Nicole Peterson Stuart Rogers Kendra Karr Possible Kelp Forest Perturbations Natural Disasters Disease And Human interaction 1

2 Why do we care? Tilman Ecology 1997 and Tilman et al. Science 1997 Nicole LaRoche Byrnes et al. Ecology Letters Nicole LaRoche Rarely tested because the steps involved are extensive and time consuming! How quickly do grazers return after perturbation? Is this dependent on: The specific removed? The number of removed? Food (kelp) abundance?

3 The Pattern: Nicole Peterson The Pattern: After a disturbance. Kelp beds with low diversity and kelp beds with high may look like this diversity may look like this Erlendur Bogason Kendra Karr 3

4 1 Species Richness vs. Days to Return 1 Goal: Removal of one or more decreases resilience, making the system more susceptible to disturbances Removing a single can have a great effect on similar in that community Aaron Baldwin Carrisa Thomas Our goal is to show that the more removed, the less stable a community becomes The less stable the community is, the more likely a disturbance can wipe out an entire system

5 The Location: Kelp Crab Pugettia spp. elasmodiver.com Our Kelp Munchers Blue top snail Callistoma ligatum Abalone Haliotis spp. Aaron Baldwin Carrisa Thomas Norris top snail Norrisa norrisi Diver.net NOAA Blue ring top snail Callistoma annulatum Gumboot Chiton Cryptochiton stelleri Wavy turban snail Lithopoma undosum Red turban snail Lithopoma gibberosum Nicole LaRoche Purple urchin Strongylocentrotus purpuratus Red urchin Strongylocentrotus francisanus Peter J. Bryant 5 L. & L. Langstroth Nicole LaRoche 5

6 Hypothesis 1: Hg: The of a community will determine how resilient and elastic a system is to a perturbance. Hs: If the determines the resilience and elasticity it of a community then communities with a of will be less resilient than, will be less resilient than and will be less resilient than. Experimental Design: Species Richness of Find site with a total possible of grazing. Build a quadrant system allowing for a possible of 5 variations of from. In the quadrant set the controls, for zero grazers and for grazers. Use a computer program to randomize placement of each into our quadrant system. Reduce the 5 quadrants down by 5%. Measure the time it takes to return to original. Species Richness of Find site with a total possible of grazing. Build a quadrant system allowing for a possible of variations of from. In the quadrant set the controls, for zero grazers and for grazers. Use a computer program to randomize placement of each into our quadrant system. Reduce the quadrants down by 5%. Measure the time it takes to return to original. Species Richness of Find site with a total possible of grazing. Build a quadrant system allowing for a possible of variations of from. In the quadrant set the controls, for zero grazers and for grazers. Use a computer program to randomize placement of each into our quadrant system. Reduce the quadrants down by 5%. Measure the time it takes to return to original. Species Richness of Find site with a total possible of grazing. Build a quadrant system allowing for a possible of 5 variations of from. In the quadrant set the controls, for zero grazers and for grazers. Use a computer program to randomize placement of each into our quadrant system. Reduce the 5 quadrants down by 5%. Measure the time it takes to return to original.

7 Our Crazy Equation AKA Fun with Factorials Possible Species A B C D E F G H I J Experimental Quadrants! Thanks Pete!! Quadrants 7

8 Predicted Results: 1 Null is rejected 1 Null is not rejected Species Richness 5 15 days control 5 15 Hypothesis : Hg: During periods of higher algal growth a community s resilience will be higher. h Hs: If a site is to be fertilized yielding higher algal growth then the resilience of that community will be higher than that of a community left un-fertilized.

9 Experimental Design: For this experiment we repeated the first experiment two more times, one with hfertilizer and one without fertilizer for the control. Predicted Results: Null is rejected Null is not rejected 1 1 richness richness richness richness richness richness richness richness fertilized nonfertilized fertilized nonfertilized 9

10 Hypothesis 3: Hg: A certain may have a more drastic effect on the resilience of a community. Hs 1 : If A has a higher resilience factor on a community, then when A is removed the resilience will be lower. Hs : If B has a lower resilience factor on a community then when B is removed the resilience will be higher. Experimental Design: Th d i f th h th i th The design for these hypotheses is the same as before with consideration to each removed

11 Predicted results: Null is rejected Null is not rejected normal randomness when a is removed When A is removed When B is removed when B is removed normal random 11