生态学概念、研究范畴及研究方法

The fittest individual

those that leave the greatest # of descendants those that transport more gene to the next generation

Example

Model: an annual, only one gene, asexual reproduction, reproduce only once in life time.
Methods of studying ecology

To understand, describe, explain, predict and control
Scale Lab experiment, field experiment, natural trajectory experiment, natural snapshot experiment, mathematical model


Secondary production: trout >> Galax
Succession of old fields

Natural trajectory vs. natural snapshot Correlation vs. mechanism

within field comparison indicated introduced sp.↑and prairie sp.↓ as N↑


Energy budget of bumblebee

How to keep warm in cold environment?
Energy gain for feeding – energy loss from flying, feeding and keeping warm Lab and field studies

Field experiment

sp. composition and N supply
Nutrients in the rain forest canopy

Epiphytes mats ~ ½ to 4x of the nutrient content of the foliage of the canopy trees

Ecology of forest birds

5 warbler sp. of similar ecological requirement
Feeding zones In the presence or absence of other species Competition and partitioning
Branches of Ecology
Chemical, Molecular, Physiological, Behavioral, Population, Community, Ecosystem, Landscape, Evolutionary, Theoretical, Conservation and management, Biodiversity
5 genotypes: A, B, C, D, and E

G, S, F = proportion of energy devoted to growth, survival (against predator), and fecundity
# of seed Genotypes Spring/Summer Fall


Number and kinds of flower visited, sugar content of flower Energy loss at different temperature

Brown trout v.s. Native Galaxias


Fish → Mayfly nymph → algae
Fitness


a measure of biological success
# of gene or genome put into the next generation the proportionate contribution that an individual makes to future generation
Journals: Behavioral Ecology, Biological
Conservation, Chemical Ecology, Conservation Biology, Conservation Ecology, Ecological Application, Ecological Modeling, Ecological Monograph, Ecologist, Ecology, Environmental Management, Evolutionary Ecology, Functional Ecology, Journal of Animal Ecology, Journal of Applied Ecology, Journal of Wildlife Management, Landscape Ecology, Molecular Ecology, Oecologia, Oikos, Trends in Evolution and Ecology, etc.
Genotype frequency before after one generation A 10/50=0.2 4/61=0.06 B 0.2 9/61=0.15 C 0.2 8/61=0.13 D 0.2 20/61=0.33 E 0.2 20/61=0.33 Fitness = # of gene/genome put into the next generation Fitness of D&E = 20/10 = 2 Fitness of C = 8/10 = 0.8 Fitness of B = 9/10 = 0.9 Fitness of A = 4/10 = 0.4


Summarizing current knowledge
Approximation and simplification


Hypotheses testing
Exploring scenarios and situations Caution in evaluation and prediction

N=S+L+I dS/dt = (b-d)S -αSI dL/dt = αSI - dL - βL dI/dt = βL - dI - γI α - contact rate β - reaction rate γ - rabies-induced mortality
Merits of model
Survival
10 10 10 10 10 Total
A B C D E
2 large 9 small 2 small 4 medium 5 med-small
2 seeds 1 seeds 4 seeds 5 seeds 4 seeds
4 9 8 20 20 61
G:F:S in A=6:1:1, B=1:1:6, C=1:6:1, D=1:1:1, E=1:1:2
Activity pattern (lab and field exp.) Habitat preference (natural exp.) Community effect (field exp.)

Trophic cascade – effects flowing down from one trophic level to the next and the next Energy flow Primary production: trout >> Galax
Questions


Is the population biologically successful?
Are those genotypes equally successful? What if increase herbivory?
Within species variation

Perennial Achillea lanulosa, transplant and reciprocal transplant Natural selection by pollution
Photosynthesis, migratory birds, bats

Fox-rabies (math model)

Assumptions: no recovery or immune, no migration, random contact Biology: life span 2 yrs., 1 cub/yr, latent phase 28 days, die 5 days after becoming infectious

Abiotic factors

来自百度文库
chemical and physical environment

Biotic factors

competition, predation, mutualism, etc.

Dispersal Behavioral factors Human factors
Factors affecting the abundance and distribution of species

Historical factors

evolution and speciation continental drift geological and climatic changes
Definition of Ecology



1866 Ernst Haeckel: the comprehensive science of the relationship of the organism to the environment 1927 Charles Elton: Scientific natural history 1963 E. P. Odum: The study of the structure and function of nature 1972 C. J. Krebs: The scientific study of the interactions that determine the distribution and abundance of organisms
Ecological spectrum
Biosphere, Landscape, Ecosystem, Community, Population, Organism, Organ system, Organ, Tissue, Cell, Subcellular organelles, Molecules


Industrial melanism

Natural selection by predation
Darwinian evolution by natural selection

individual variation
variation is heritable
differential reproductive rate

the interaction between the characteristics of individual and the environment