Mary Power mepower berkeley edu http ib berkeley edu labs power Ecology office hours M W 9 10 am Bio 1b office And by appointment Ecology oikos house logos study Scientific study of interactions of organisms with their environments organism Study of factors that determine the distribution and abundance of organisms Andrewartha and Birch 1954 1 2 Lab results compared caterpillar feeding and growth rates on nitrogen enriched vs non enriched leaves 3 Niemala a Finnish ecologist found that birch leaves were eaten faster by caterpillars and caterpillars grew faster when leaves were enriched with nitrogen as they are from acid rain but that trees growing for 5 10 years in outdoor nitrogen fertilized plots were less grazed than were trees in unfertilized plots 4 Predators overrecruited to fertilized trees in the field plots predators herbivores plants Unfertilized Fertilized 5 6 Methods in Ecology Observations Observations Experiments Models The only way truly new information is acquired Good natural history Consistent long term monitoring Nowadays Advanced mapping sensing and tracing technologies Experiments Field or laboratory replicated manipulated treatments with controls Whole ecosystem experiments lake fertilization and acidification Schindler experiment Hubbard Brook deforestation Likens experiment Models verbal or mathematical simplifications of reality intended to capture key processes that change systems over time Hypotheses suggested explanations subject to test falsifiable 7 Observations Technology and natural history 13 17 species of bats in California Bill Rainey Dixie Pierson husband wife conservation biology team Deduction predicting specific outcomes from general models Models hypotheses 8 ultrasonic acoustic detection to identify most species and estimate collective foraging activity Tests observations or experiments Induction generalizing from specific observations to more general models 9 Remote sensing e g airborne laser altimetry Digital Elevation Models and predictions of environmental conditions e g light temperature regimes 11 10 Airborne Laser Swath Mapping LiDar 1978 2006 12 New sensing mapping and tracing technologies To the Internet and beyond Northern California melted ice cream topography Landslide dominated 13 14 Observations Mo orea French Polynesia pillow stars have colormatched shrimp The only way truly new information is acquired Good natural history Consistent long term monitoring Advanced mapping and sensing technologies Experiments Field or laboratory replicated manipulated treatments with controls Whole ecosystem experiments Berkeley students at UCB Gump Marine Lab Mo orea 15 16 Hypothesis 1 Diet color derived from food shrimp acquires color from eating starfish or diet of starfish Hypothesis 2 Behavioral habitat selection Shrimp select color matched starfish as their habitat 17 18 Transplant experiments to test whether shrimp acquires color from starfish or its environment or diet How would you test these hypotheses In the lab or the field Choice experiment see if shrimp chooses starfish of appropriate color 19 20 Meadow food web response to doubled rainfall and changed seasonal timing Spiders Blake Suttle Ph D dissertation Grasshoppers Melanoplus devastator 5 plant guilds Soil moisture N 21 Tools for dealing with ecological variability Replicates are separate independent units of study that are treated as identically as possible in order to assess variability that arises from factors we didn t manipulate 22 Patterns that demand explanation Marine intertidal grazing halos photos by Wayne Sousa Controls are unmanipulated units that provide a baseline for comparison an understanding of how organisms or systems will change over space or time independent of experimental treatments Statistics tools for distinguishing signal from noise e g test whether differences between treatments e g control vs experimental are greater than differences within treatments 23 24 Grazer exclosure copper paint Site preparation for nutrient diffusing x grazer excluding flower pot experiment Tatoosh Island Bird exclosures above Tim Wootton letter boxes side PVC and bird netting 25 5 light levels X 5 replicates 25 channels Effects of light algal productivity on river food webs 26 Effects of nutrients and animals on algal accrual in rivers Jane Marks Northern Arizona Univ 27 Replication may be difficult or possible at whole ecosystem scales David Schindler experimental lakes added C N and P pea green eutrophied lake vs C and N blue lake 29 28 Experiments Field or laboratory replicated manipulated treatments with controls Whole ecosystem experiments Schindler s lake fertilization and acidification p 1205 Fig 54 8 in Campbell Hubbard Brook deforestation 30 Observations The only way truly new information is acquired Good natural history Consistent long term monitoring Advanced mapping and sensing technologies Experiments Field or laboratory replicated manipulated treatments with controls Whole ecosystem experiments Schindler s lake fertilization and acidification p 1205 Fig 54 8 in Campbell Hubbard Brook deforestation Models verbal or mathematical simplifications of reality intended to capture key processes driving system change over time Hypotheses suggested explanations subject to test falsifiable Deduction predicting specific outcomes from general models Models hypotheses Tests observations or experiments Induction generalizing from specific observations to more general models 31 32 Understanding ecological patterns and processes requires both Reductionist approaches seeking mechanisms causal processes e g caterpillars feed and grow faster on nitrogen rich leaves lab spoon vs chop stick feeders mechanism affects efficiency and Holistic approaches determining boundaries of the system all that must be included necessary for understanding and predicting outcomes of ecological interactions in the real world lab how do diets experience environmental context affect success and eventual composition of foragers on VLSB lawn Zoom lens ecology focus in for mechanism zoom out 33 for context and consequences 2 species Taxon Strong interactions Food chain 34 Environment Lecture 2 Climate microclimates and biomes Lecture 3 Resources conditions and the fundamental niche in aquatic and terrestrial environments energy time 2 species space Food chain Taxon or guild Strong interactions 35 36 Environment 2 Climate microclimates and biomes 3 Resources conditions and the fundamental niche in
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