BIOEE 1610 1st Edition Lecture 14Outline of previous lectureI. Trophic cascadesII. DiversityA) ComponentsB) Shannon indexC) Rank-abundance curvesIII. Spatial scales of diversityA) Alpha, beta, gamma diversityOutline of current lectureI. AnnouncementsII. Geographical ecologyIII. Species-area relationshipsIV. The theory of island biogeographyV. Design of core natural reservesVI. DiversityCurrent lectureI. Announcements*Prelim:-Thursday March 16 (contains material through THIS lecture)-Students with last names A-K: Riley Robb 125-Students with last names L-Z: Plant Science 233*Review sessions: Sunday March 22 5-6pm, Tuesday March 24 5-6pm*Section: meet at Triphammer footbridge on Beebe LakeII. Geographical ecology*The study of ecological structure and processes at large special scales*” the search for patterns f plant and animal life that can be put on a map”III. Species-area relationships*Alexander von Humboldt (1807): larger areas harbor more species than smaller areas*Exemplified by the finches on the Galapagos Islands… larger islands have more species, in general*Not limited to islands in the middle of the ocean… can also be observed in “sky islands” (a mountaintop among lower elevation lands around it) and other fragmented areas*Also: the closer the island is to mainland tends to harbor more species than those far away of the same sizeThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.IV. The theory of island biogeography*The number of species on an island is a dynamic equilibrium between rates of immigration and rates of extinctionImmigration rate Extinction rateEquilibrium# of species on island*If the island is closer to the mainland: the immigration graph will be shallower because the immigration rates are lower*If island is larger in size: the extinction curve will be shallower because the extinction rates are lower*Immigration rates are mostly affected by distance from mainland*Extinction rates are mostly affected by island size*In terms of # of species: Large & near>small & near>large & far>small & far*Study of island biogeography-Fumigated mangrove islands, killing all herbivorous arthropods, measured rates of its subsequent immigration from the nearby islandsNear islandFar island-His next experiment was to use a chainsaw to lower the size of the mangrove islands: the results fit the model*Habitat loss and fragmentation-Lowers “island” size and distance from other islands-Example: the loss and fragmentation of the forest of the golden lion tamarin *Another study:-Plots of 1, 10, 100, and 1000 hectares surrounded by deforested land (or not for controlgroups)-Numbers of bird species in each matched the model, both in expected immigration and in expected extinction-What size do you need for an effective conservation area?V. Design of core natural areasBetter WorseReserve size SLOSSReserve proximityReserve connectivityReserve shapeVI. Diversity*In general, diversity if greater at latitudes closer to the equator*Tropical rainforests are more diverse than temperate (biome is important)*Patterns with DECRESING LATITUDE:-Higher local diversity-Higher regional diversity-Higher species turnover-Higher functional group/guild diversity-Higher evenness *Exceptions to these rules: Seabird diversity is actually lower in the tropics than the poles (this isbecause of higher ocean productivity in the polar and temperate oceans)*Why are the tropics so diverse?-Need to distinguish between origin and maintenance -More than 25 hypothesis (more time of species diversification because of no glaciation, larger areas to support more species [species-area], favorable climate [energy hypothesis], higher productivity, greater intensity of biotic interactions [temperate: few species with large niches because of lower competition; tropical: many species with narrower niches because of higher competition], predation). These are also not mutually