Introduction to Ecology Flashcards
is the scientific study of the distribution and abundance of organisms, and their interactions with the environment.
Ecology
The roots of ecology, “oikos” and “logos” mean..
Oikos - House
Logos - Study
The scientific approach dating back to European enlightenment of sixteenth and seventeenth centuries
Hypothetico - deductive approach
The scientific sequence
Observations - Hypothesis - Predictions - Experiment
A suggested explanation for a phenomena, based upon a conceptual working model of how a system works
Hypothesis
If predictions of the hypothesis are not correct, it becomes
Falsified
Result after hypotheses are held true for multiple experiments, they explain how the world works and they inspire future research but limit its direction
Scientific Paradigms
The zonesomata fly experiment tested why the wings evolved, what was confirmed?
They evolved them to scare away jumping spiders because the jumping spiders did not attack zonesemata with their own wings.
Why does ecology lack a single scientific paradigm? In other words, why is it an exciting field where new discoveries can have an enormous impact?
Because many of its underlying ideas have not been suffieciently tested or have crumbled.
The four levels of organization in ecology
Individuals
Populations
Communities
Ecosystems
Is it always easy to identify individuals (single, discrete organisms)?
No. The distinction can be arbitrary or nonexistent like Aspen trees or fungus mycellium which are all interconnected underground.
What kind of ecology examines how a cave cricket finds its way in and out of the entrance of a cave?
Organismal Ecology
Very frequently, these questions concern abundance, density, population growth, and limits to growth. For instance, this ecologist might study the extent to which the number of available nest sites affects the maximum number of tropicbirds an island can sustain.
Population Ecology
This ecologist might ask questions about the extent to which parasitic wasps control outbreaks of pine sawflies, and whether the presence of parasitoids is necessary for the presence of pine trees.
Community Ecologist
interacting assemblages of living things living in a particular area, accounting also for the nonliving components, such as light, water, nutrients, soil, and seasonality, that are important to life.
Ecosystem Ecologist
True/False: There are ecosystems nested within other ecosystems
True
might ask questions about the role of bat guano entering the caves, and the extent to which nutrients and energy brought in by the bats from outside, via their guano, support the nonphotosynthetic ecosystem in the cave.
Ecosystem Ecology
Says that a species is a group of actually or potentially interbreeding organisms that can mate and produce fertile offspring
Biological Species Concept
Says that species are groups of organisms that share certain morphological or biochemical traits, used to study fossils
Morphological species concept
A species is a discrete lineage, propagated, ancestor to descendent through time, which is recognizably different from other such lineages and shares a distinct evolutionary history. It defines a species by its relationship to other species.
Phylogenic Species Concept
Researchers examined the importance of birds in controlling herbivores by putting some trees in cages. This was an example of
Ecological Hypothesis Test
Are ecological experiments often reproducible? Why or why not
No. Conditions vary from year to year and place to place. This yields mixed results.
Shorter than the evolutionary time scale, it represents ecological time scales that may occur over days to millenia.
Ecological Time Scale
broad assemblages of plant and animal communities generally defined by the dominant vegetation
Biomes
Paint a broad swath of an area based upon what the dominant vegetation looks like.
Biomes
Major ecosystems that result from predictable patterns of climate as influenced by latitude, global position, and climate. More specific form of biomes.
Ecoregion
have characteristic vegetation determined by the amount and timing of water, the amount of available sunlight, and by temperature.
Terrestrial Biomes
provides a spatial structure to terrestrial biomes
Vegetation
creates micro-environments important to various different organisms
Spatial Structure
The 4 major physical factors that influence terrestrial biomes
Rainfall
Timing of rainfall
Sunlight
Disturbance
Warm wet areas favor…
Intermediate areas favor….
Little precipitation favors…
Rainforests
Grassland or forest (depending on seasonality)
Tundra and desert
characterized by the lack of trees, the dominant vegetation is lichens, annual grasses, and, in some places, very specially adapted shrubs and woody plants.
Plants and insects flourish during the short growing season
Tundra
occurs in polar climates and at high elevations, where the growing season is very short. Nearly all precipitation falls as snow
Tundra
Cone-bearing trees such as pine, spruce, and fir dominate. most are dominated by one or a few species
Taiga or Coniferous Forest
This biome is very common, covering huge areas at high latitudes or high elevations
Taiga or Coniferous Forest
The cool to warm summers are the growing season
Plants are dormant during the winter, when temperatures drop far too low for photosynthesis.
Often, much of the precipitation falls as snow. Snow melt releases a great deal of water into the communities that make up the taiga
Taiga or Coniferous Forest
Low rainfall, generally less than 30cm per year
Many are very hot (at least during the day), but some, such as the Great Basin and the Gobi, are cold most of the year
Desert
The dry environment often causes a dramatic difference in temperature between day and night
Desert
Grasses are usually found when water is available (they are dormant underground, or as seeds, when there is no water).
Succulents, such as cacti and euphorbs, and shrubs with specialized water-saving adaptations, are present.
Trees are uncommon or totally absent.
Desert
Cool, rainy winters and dry summers
Dense, spiny, evergreen shrubs dominate
Seasonal fires
Most of the plants are fire-adapted. Many species can only reproduce via periodic fires
Chaparral
This biome has high biodiversity, with a great deal of endemism.
Chaparral
This biome is rather uncommon, being confined to relatively few locations with a Mediterranean climate, California, Costal South America, South Africa, the Mediterranean, and Western Australia
Chaparral
Grasses and forbs dominate. Fire and grazing prevent the establishment of shrubs and trees
Moderate to low rainfall and a wide range of temperatures permit grasslands
Grassland
Seasonal drought, occasional fires, and grazing by herbivores prevent the establishment of trees as the dominant vegetation
It is a widespread biome
Grassland
grassland mixed with scattered trees (sometimes it is considered its own biome
Savannah
Moderate rainfall and mild to warm summers with cool to cold winters.
Occur at mid-latitudes, where moisture is sufficient to support the growth of large trees
Temperate Deciduous Forest
Winters are cold enough to prohibit photosynthesis, and most organisms go dormant or hibernate over the winter
Temperate Deciduous Forest
Dense stands of deciduous trees predominate
Trees tend to have distinct vertical layers; including one or two strata of trees and an understory of shrubs
Temperate Deciduous Forest
The most productive biome on the planet, also harbors the most biodiversity.
Most are located near the equator, where temperatures are warm and relatively constant year round
Tropical Rain Forest
Plants are broad-leafed evergreen trees, shrubs, woody vines, and epiphytes.
Tropical Rainforests
plants that live on other plants, usually trees. Examples include orchids and mistletoe
Epiphytes
High rainfall-usually with a pronounced rainy season and dry season.
Competition for light is intense. Pronounced stratification with several layers of trees.
Tropical Rainforest
tend to occur in lowland areas, where the distinction between the wet season and the dry season can be very pronounced
deciduous trees, thorny shrubs, and succulents are very common
Tropical Dry Forests
The broadest categorizations of terrain, divided into divisions and provinces
Domains
The term “biome” is not generally applied to aquatic environments, though the oceans have been broken into
Oceanic Regions
Water provides spatial structure in aquatic environments?
Water columns
Light penetrates the top few meters
Except in areas of upwelling, nutrient concentrations are generally low, because the remains of dead organisms sink to the bottom of the ocean.
Pelagic Zone
All organisms are floating or free-swimming “nekton”. The major producers are photosynthetic algae.
Pelagic Zone
Nutrients reach this zone by falling from pelagic zones.
Light is absent. This zone supports a wide variety of specially-adapted organisms
Abyssal Zone
areas covered in water that support aquatic plants
They range from periodically flooded regions, to soil that is saturated with water during the growing season, to permanently flooded areas
Wetlands
Wetlands that occur at the mouths of rivers
Estuaries
Wetlands that are flooded areas dominated by trees
Swamps
Wetlands that are flooded areas dominated by sedges and grasses
Marshes
Which direction on the earth does biodiversity increase, it’s called the latitudinal gradient
Towards the equator
True/False: Reason for increasing biodiversity towards equator is clear cut
No
Theories of why biodiversity increases towards tropics.
1) greater productivity in tropics
2) history
3) complexity of habitats
4) less disturbance
