Microbiome, antibiotics, Germs R us, appendix = “ bomb shelter ”
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Transcript of Microbiome, antibiotics, Germs R us, appendix = “ bomb shelter ”
Energy Money Land Food Water SewageSolutionsSpace Travel
Third Exam Thursday 3 December 2015Chapters 11-15, 17-18 plus 8 readings
Final Exam -- 9 December -- 2-5 PM
25th Lecture19 November 2015
Dan Janzen
Janzen’s Seedling Ring Model
Pine squirrels (Tamiasciurus) and coniferous food trees (Smith 1970)
Squirrels are very effective seed predators, stockpile cones Chris Smith
Trees reduce squirrel effectiveness in many different ways:1. Cones difficult for squirrels to reach, open, or carry2. Putting fewer seeds in each cone (fake cones without any seeds)3. Increasing thickness of seed coats (seeds harder to harvest)4. Putting less energy into each seed (smaller seeds)5. Shedding seeds from cones early, before young squirrels forage6. Periodic cone crop failures decimate squirrel populations
Individual trees out of synchrony would set fewer seeds and thusbe selected against.
Coevolution
Joint evolution of two (or more) taxa that have close
ecological relationships but do not exchange genes, and in which reciprocal selective pressures operate to make the evolution of either taxon partially dependent on the evolution of the other.
Enterobius Pinworms and Primate Hosts Parallel Phylogenies
Some of the Suggested Correlates of Plant Apparency _____________________________________________________________________________ Apparent Plants Unapparent Plants _____________________________________________________________________________ Common or conspicuous Rare or ephemeralWoody perennials Herbaceous annualsLong leaf life span Short-lived leavesSlow growing, competitive species Faster growing, often fugitive speciesLate stages of succession, climax Early stages of succession, second growth
Bound to be found by herbivores Protected from herbivores by escape in (cannot escape in time and space) time and space (but still encountered by
wide-ranging generalized herbivores)
Produce more expensive quantitative Produce inexpensive qualitative chemical(broad-based) antiherbivore defenses defenses (poisons or toxins) to discourage(tough leaves, thorns, tannins) generalized herbivores
Quantitative defenses constitute Qualitative defenses may be broken downeffective ecological barriers to her- over evolutionary time by coevolution ofbivores, although perhaps only a weak appropriate detoxification mechanisms inevolutionary barrier unless supple- herbivores (host plant-specific herbivoremented with qualitative defenses species result)_____________________________________________________________________________
Paul Feeny
Community and Ecosystem Ecology
Macrodescriptors = Aggregate Variables
Trophic structure, food webs, connectance,
rates of energy fixation and flow, ecological efficiency,
species diversity, stability, relative importance curves,
guild structure, successional stages
Bottom Line. Communities are not designed by natural selection
for smooth and efficient function, but are composed of many
antagonists
(we need to attempt to understand them in terms of interactions
between individual organisms)
Energy Flow and Ecological Energetics
Gross Productivity = rate at which plants capture solar energy
Gross annual production (GAP)
Net productivity = gross productivity minus respiration losses
Net annual production (NAP)
Respiration in tropical rainforest 75-80% of GAP
Respiration in temperate forests 50-75% of GAP
In most other communities, it is 25-50 % of GAP
Only about 5-10% of plant food is harvested by animals
Remainder of NAP is consumed by decomposers
Biogeochemical cycles
Hydrologic Cycle
Biogeochemical Cycle for Calcium
Aldo Leopold, A Sand County Almanac X
CompartmentationTrophic Levels
Autotrophs = producers
Heterotrophs = consumers & decomposersPrimary carnivores = secondary consumersSecondary carnivores = tertiary consumersTrophic continuumHorizontal versus vertical interactionsWithin and between trophic levels
Guild StructureFoliage gleaning insectivorous birds
Food WebsSubwebs, sink vs. source food webs
Connectance [n (n-1)] / 2
Energy Flow and Ecological Energetics
Energy Flow and Ecological Energetics
Energy Flow and Ecological Energetics
At equilibrium (di/dt = 0 for all i), energy flow in the system
portrayed in the figure may thus be represented by a set of
simple equations (with inputs on the left and rate of outflow to
the right of the equal signs):
10 = 01 + 02 + 03 + 04
10 = 21 + 01 + 41
21 = 32 + 02 + 42
32 = 03 + 43
41 + 42 + 43 = 04
Systems Ecology
Food Web
Paine (1966)
Food Web
Bottom Line
Kirk Winemiller
Ecological Pyramids (numbers, biomass, and energy)
Pyramid of energy
Measures of standing crop versus rates of flow
Secondary Succession
Institute Woods in Princeton
Transition Matrix for Institute Woods in Princeton
_________________________________________________________________________Canopy Sapling Species (%)Species BTA GB SF BG SG WO OK HI TU RM BE Total __________________________________________________________________________
BT Aspen 3 5 9 6 6 - 2 4 2 60 3 104Gray birch - - 47 12 8 2 8 0 3 17 3 837Sassafras 3 1 10 3 6 3 10 12 - 37 15 68Blackgum 1 1 3 20 9 1 7 6 10 25 17 80Sweetgum - - 16 0 31 0 7 7 5 27 7 662White Oak - - 6 7 4 10 7 3 14 32 17 71Red Oak - - 2 11 7 6 8 8 8 33 17 266Hickory - - 1 3 1 3 13 4 9 49 17 223Tuliptree - - 2 4 4 - 11 7 9 29 34 81Red Maple - - 13 10 9 2 8 19 3 13 23 489Beech - - - 2 1 1 1 1 8 6 80 405__________________________________________________________________________BTA in next generation = 0.03 BTA + 0.03 SF + 0.01 BG. Grand Total = 3286
Henry Horn
Distributions of Trees Observed in 4 Forests and Predicted Climax__________________________________________________________________ __________________ Age (years) BTA GB SF BG SG WO OK HI TU RM BE __________________________________________________________________ __________________
25 0 49 2 7 18 0 3 0 0 20 1 65 26 6 0 45 0 0 12 1 4 6 0 150 - - 0 1 5 0 22 0 0 70 2 350 - - - 6 - 3 - 0 14 1 76
Predicted climax 0 0 2 3 4 2 4 6 6 10 63__________________________________________________________________ __________________
Data from theInstitute Woods in Princeton (Horn 1975)
Henry Horn
Diversity and Community Stability
Saturation with Individuals and with Species
Species Diversity = Biodiversity
Species Density or Species Richness
Relative Importance
Equitability
Janzen’s Seedling Ring Hypothesis
Tamiasciurus squirrel seed predation
Community and Ecosystem Ecology
Macrodescriptors = Aggregate Variables
Compartment models, trophic structure, food webs,
connectance, rates of energy fixation and flow,
biogeochemical cycles, ecological energetics,
ecological efficiency, trophic continuum, guild structure,
ecological pyramids, successional stages, transition
matrix,
species diversity, stability, relative importance curves.
Diversity and Community Stability
Saturation with Individuals and with Species
Species Diversity = Biodiversity
Species Density or Species Richness
Relative Abundance/Importance
Equitability
Species Diversity, Relative Abundance
Species Site A Site B A 10 91 B 10 1 C 10 1 D 10 1 E 10 1 F 10 1 G 10 1 H 10 1 I 10 1 J 10 1
Relative Abundance / Importance
Ways two systems can differ in diversity
All 10 Sites: Total Number of lizards: 20,990
Total numbers of lizards of 67 species collected on 10 desert study sites from1966-2008 plotted against their ranks inrelative abundance. The 12 most common species (blue) are named, along with 7 of the 54 less common to rare species (red). Samples exceed 30 for 48 of the 67 species.
Discriminant function analysis showing clear separation of rare species based on 10 ecological variables including body size, clutch size, niche breadths and overlaps for diet, microhabitat, and habitat.
Robert H. MacArthur
Geographical Ecology
1. Degree of Saturation
2. Range of Available Resources
3. Average Niche Breadth
4. Average Niche Overlap
Species Diversity = “Biodiversity” Regional <—> Local <—> Point diversity
Saturation with species
Four ways in which diversity can differ
1. Range of available resources
2. Degree of saturation
3. Niche breadth
4. Degree of niche overlap
I was a mere graduate student, wet behind the ears, only 25 years old, when I wrote it. I don’t usually re-read my own papers – but now, 5 decades later, I am pleased to find it cerebral and fairly well written.
Latitudinal gradients in diversity
Time theories, degree of saturation with species
Climatic stability and climatic predictability, niche breadth
Spatial heterogeneity, range of available resources
Productivity and stability of productivity
Competition —> specialization, narrow niches, higher diversity
Disturbance, intermediate disturbance hypothesis, niche overlap
Predation-induced diversity (Paine’s Pisaster experiment)
Productivity Hypothesis
Intermediate Disturbance Hypothesis