Ecosystems and Species
Ecosystem (community): a distinct assemblage of populations of living things that inhabits a natural area of land or water
- occurs naturally on the landscape wherever certain physical conditions occur
- “natural” is a relative term
Ecosystems and Species
Species: A distinct group of organisms that can reproduce its own kind
- don’t have to look alike- must be able to produce fertile offspring
Ecosystems and Species
How to write a species name:
Genus name (capitalized) + specific epithet (never capitalized)
- if typed, it should be in italics; if written, it should be underlined
For instance: Homo sapiens Felis domesticus
Ecosystems and Species
Native: a species that has existed in a place for a long period of time and is adapted to local conditions
- often has complex interrelationships with other native species
Exotics: species that have been introduced from some other part of the world
Ecosystems and Species
Weeds: plants that move into an area rapidly and spread quickly
- weeds can be native or non-native; native weeds are usually somewhat controlled by their predators
Invasives: species that spread out of control (this is more likely to happen if the species is exotic)
Ecosystems and Species
A natural ecosystem will be made up of a particular assemblage of species occupying a particular landscape feature
- sandhill- saltwater marsh- sinkhole pond- cave, etc.
The species in an ecosystem are genetically adapted to thrive there
Ecosystems and Species
Usually natural ecosystems tend to persist, as long as things don’t change from what they are adapted to
- some ecosystems are adapted to a high level of disturbance (e.g. Carribean coastlines)- some don’t tolerate disturbance well (e.g. tropical rainforests)
Ecosystems and Species
A natural ecosystem often provides services to other ecosystems and to humans:• regulating climate• purifying air and water• moderating floods• producing foods• much more
Florida’s Species
This class will focus on species from three kingdoms:1. plants2. animals3. fungi (to a lesser extent)
We won’t look at microscopic species (but there’s plenty!)
Florida’s Species1. Plants
- We will focus mainly on vascular plants: ferns, flowering plants, and conifers
2. Animals- We will focus mainly on vertebrates: birds, reptiles, amphibians, and fish- We will identify insects where we can (they are the most abundant group on earth!)
3. Fungi- mushrooms, mainly
Florida’s SpeciesFlorida native species number in the tens of thousands
Some exist only in Florida (endemic species)
Species that only live in a limited area are more likely to go extinct
- compared to the rest of the country, Florida has a larger than average
percentage of species at risk for extinction
Florida’s Physical Environment
It’s the physical features of the environment that shape the species that live there (through natural selection)
- climate- topography- soils- waters
Florida’s Physical EnvironmentClimate
- the long-term features and events of the atmosphere- weather is a part of climate but it
describes short-term events
- temperature, humidity, wind speed and direction, types of storms
Florida’s Physical EnvironmentClimate
- because Florida is a long state from north to south, climate conditions vary• mostly temperate• subtropical in south FL• tropical in the Keys
- overall, temperature variations are moderate
Florida’s Physical EnvironmentClimate
- as a peninsula, FL is protected against temperature extremes and is exposed to high humidity
• warm Gulf water plays a big role• most other lands at this latitude are desert
• rainfall is abundant during the rainy season (on average 53 inches per year)
Florida’s Physical EnvironmentClimate
- all of FL has alternating wet and dry seasons, although the timing varies between north and south
• wet summers (June, July, August)• dry fall/winter (Oct., Nov., Dec.)• wet late winter in North (Jan. – April)
- plants and animals must be adapted to go weeks without rain
Florida’s Physical EnvironmentClimate
- hydroperiod (timing of wet and dry periods) is of great importance for some species
- e.g. plants, amphibians
- dry periods with lightning may lead to fires- some species are not only adapted to fire, but depend on it
Florida’s Physical EnvironmentClimate
- tropical storms and hurricanes- high winds, flooding rain, storm surges
- coastal species tend to be very resilient – they come back quickly from storm damage
Florida’s Physical EnvironmentSediments/ Soils
- the southeastern U.S. coastal plain has three main kinds of sediments:
1. marine sediments (laid down when FL was at the bottom of the ocean – limestone and dolomite)
2. clastic sediments (clay, silt, sand, gravel), from the Appalachian mts.
3. organic sediment from the decomposition of living things
Florida’s Physical EnvironmentSediments/ Soils
- FL’s soils are made of some mixture of the three types of sediments
- the more organic sediment, the more water the soil can hold
- but, too much water in the soil means not enough oxygen
Plants can be classified by what kind of soil they prefer: xeric (dry), mesic (moist), or hydric (wet)
Florida’s Physical EnvironmentTopography
- because of past changes in sea level, FL has been both wider and narrower than it is today- high areas in the interior often have the remains of dunes that were once along the shore
Florida’s Physical EnvironmentTopography
- the three topographical zones of FL:
1. highlands/ridges/upland plains- distinguished by the clay to soil ratio
2. lowlands- low and flat, sometimes wet
3. coastal- salty, or a mix of salt and fresh water
Florida’s Physical EnvironmentTopography
- limestone/ karst topography- jagged, porous limestone that may be exposed or may lay under other sediment types
- Floridan Aquifer – the reserve of water-saturated limestone that lies under a large portion of the state