Biomes

1
Biomes

• A distinct ecological community of plants and
  animals living together in a particular climate
  is called a "biome.

2
(No Transcript)
3
The concept of an ecosystem

• An ecosystem consists of the biological
  community that occurs in some locale, and the
  physical and chemical factors that make up its
  non-living or abiotic environment.

4
Ecosystems
5
(No Transcript)
6
Organisation within an ecosystem

• population
• community
• habitat
• niche

7
Population
8
Community
9
Habitat
10
Niche

• A given animal or plant lives in a
  particular place, is active at particular times
  and eats particular things, and these factors
  define its ecological niche.
• The environment is divided into millions of
  ecological niches, each of which represents a
  potential 'home' for life. Animals and plants
  will always try and take advantage of new
  opportunities, and so will always attempt to make
  a 'home' in an empty niche.
• In general, only one animal or plant can
  occupy a particular ecological niche - when two
  organisms try to occupy the same niche they will
  compete for the same resources, and one will
  always out-compete the other. However, when a
  niche becomes vacant - for example when the
  species which occupied it becomes extinct - there
  is a race to try and fill it. Mass extinctions
  open up a multitude of niches, and there is an
  evolutionary explosion as animals and plants
  adapt to fill the vacant 'homes'.
• As the Earth's environment changes over time
  some niches may be destroyed, driving the species
  which occupied them to extinction - they
  literally lose their ecological home.

11
Physical factors

• temperature
• humidity
• water
• salinity
• light
• pH
• soils
• nutrients
• Wind

12
temperature

• The whale is normally seen in the deep
  northern Atlantic. Scientists have said
  fluctuating ocean temperatures, predators, lack
  of food and even sonar from ships can send whales
  into waters that are dangerous for the mammals

13
humidity
14
water
15
salinity

• Concentration of dissolved salts found in a
  sample of water. Measured as the total amount of
  dissolved salts in parts per thousand. Seawater
  has an average salinity of about 34 parts per
  thousand (ppt).

16
light
17
(No Transcript)
18
pH

• Scale used to measure the alkalinity or
  acidity of a substance through the determination
  of the concentration of hydrogen ions in
  solution. A pH of 7.0 is neutral. Values below
  7.0, to a minimum of 0.0, indicate increasing
  acidity. Values above 7.0, to a maximum of 14.0,
  indicate increasing alkalinity. Soil pH (a
  measure of the acidity or alkalinity of the
  soil)? ???Soil pH is one of the most important
  soil properties that affects the availability of
  nutrients.
• Macronutrients tend to be less available in
  soils with low pH. Micronutrients tend to be less
  available in soils with high pH. Lime can be
  added to the soil to make it less sour (acid) and
  also supplies calcium and magnesium for plants to
  use. Lime also raises the pH to the desired range
  of 6.0 to 6.5. In this pH range, nutrients are
  more readily available to plants, and microbial
  populations in the soil increase. Microbes
  convert nitrogen and sulfur to forms that plants
  can use. Lime also enhances the physical
  properties of the soil that promote water and air
  movement.

19
soils

• Soil Texture (the amount of sand, silt,
  clay, and organic matter in the soil).
• Soil texture affects how well nutrients and
  water are retained in the soil. Clays and organic
  soils hold nutrients and water much better than
  sandy soils. As water drains from sandy soils, it
  often carries nutrients along with it. This
  condition is called leaching. When nutrients
  leach into the soil, they are not available for
  plants to use. An ideal soil contains equivalent
  portions of sand, silt, clay, and organic matter.
  Soils across North Carolina vary in their texture
  and nutrient content, which makes some soils more
  productive than others. Sometimes, the nutrients
  that plants need occur naturally in the soil.
  Othertimes, they must be added to the soil as
  lime or fertilizer.

20
nutrients

• Non-Mineral Nutrients

The Non-Mineral Nutrients are hydrogen
(H), oxygen (O), carbon (C). These
nutrients are found in the air and water.
In a process called photosynthesis, plants use
energy from the sun to change c carbon
dioxide (CO2 - carbon and oxygen) and water (H2O-
hydrogen and oxygen) into starches and
sugars. These starches and sugars are the plant's
food. Photosynthesis means "making things
with light"
21

• The 13 mineral nutrients, which come from the
  soil, are dissolved in water and absorbed through
  a plant's roots. There are not always enough of
  these nutrients in the soil for a plant to grow
  healthy. This is why many farmers and gardeners
  use fertilizers to add the nutrients to the soil.
  
• The mineral nutrients are divided into two
  groups
• macronutrients and micronutrients.
• Macronutrients
• Macronutrients can be broken into two more
  groups
• primary and secondary nutrients.
• The primary nutrients are nitrogen (N),
  phosphorus (P), and potassium (K). These major
  nutrients usually are lacking from the soil first
  because plants use large amounts for their growth
  and survival.
• The secondary nutrients are calcium (Ca),
  magnesium (Mg), and sulfur (S). There are usually
  enough of these nutrients in the soil so
  fertilization is not always needed. Also, large
  amounts of Calcium and Magnesium are added when
  lime is applied to acidic soils. Sulfur is
  usually found in sufficient amounts from the slow
  decomposition of soil organic matter, an
  important reason for not throwing out grass
  clippings and leaves.

22

• Micronutrients
• Micronutrients are those elements
  essential for plant growth which are needed in
  only very small (micro) quantities . These
  elements are sometimes called minor elements or
  trace elements, but use of the term micronutrient
  is encouraged by the American Society of Agronomy
  and the Soil Science Society of America. The
  micronutrients are boron (B), copper (Cu), iron
  (Fe), chloride (Cl), manganese (Mn), molybdenum
  (Mo) and zinc (Zn). Recycling organic matter such
  as grass clippings and tree leaves is an
  excellent way of providing micronutrients (as
  well as macronutrients) to growing plants.

23
wind
24
Relationships of living organisms

• producers
• consumers
• food chains and webs
• competition
• predation
• pollination
• dispersal
• vegetational succession

25
Producers
26
consumers

• Consumers get their energy from the carbon
  bonds made by the producers. Another word for a
  consumer is a heterotroph. Based on what they
  eat, we can distinguish between 4 types of
  heterotrophs
• consumer trophic level
  food source
• Herbivores primary
  plants
• Carnivores secondary or higher animals
  
• Omnivores all levels
  plants animals
• Detritivores ---------------
  detritus

27
competition

• 2 species compete for the same resource if
  there is not enough to support both.
• Examples A Douglas Fir Western Hemlock grow
  together in the mixed conifer forests of Oregon,
  competing for minerals, water, and light. A scrub
  jay and a gray squirrel compete for nuts and
  seeds within the oak forest.

28
predation

• A consumer feeds on another consumer.
• Examples The cougar is a predator of
  black-tailed deer. The great white shark is a
  predator of harbor seals.

29
pollination
Pollination is an important step in the
reproduction of seed plants the transfer of
pollen grains (male gametes) to the plant carpel,
the structure that contains the ovule (female
gamete).
30
dispersal

• The movement of organisms from one place to
  another is called dispersal.

Whirling Nut (Gyrocarpus)
31
Vegetational succession

• SuccessionDirectional cumulative change in the
  types plant species that occupy a given area,
  through time.

32
Energy flows

• photosynthesis
• respiration
• food chains
• food webs

33
Energy Flow Through the Ecosystem
34
photosynthesis
35
respiration
Aerobic respiration is the release of energy from
glucose or another organic substrate in the
presence of Oxygen. Strictly speaking aerobic
means in air, but it is the Oxygen in the air
which is necessary for aerobic respiration.
Anaerobic respiration is in the absence of air.

• Glucose Oxygen Carbon Dioxide Water Energy

36
Food chains

• A food chain is the path of food from a given
  final consumer back to a producer. For instance,
  a typical food chain in a field ecosystem might
  be
• grass ---gt grasshopper --gt mouse ---gt snake ---gt
  haw

37
Food webs
38
Nutrient cycling

• carbon cycle
• nitrogen cycle

39
carbon cycle
40
Nitrogen cycle

• Biological Fixation?
• Legumes, a special group of plants, are able
  to make or "fix" nitrogen. Special bacteria live
  on the roots of legumes. The bacteria receive
  "food" in the form of carbohydrates from the
  plants. In return, the bacteria use elemental
  nitrogen (N2) and change it to organic forms of
  nitrogen that the plant can use.

41
(No Transcript)
42
Resource potential

• biodiversity as a genetic resource
• and as a food base

43
Biodiversity as a genetic resource

• Wild varieties possess genetic resistance to
  pests, therefore represent a form of biological
  insurance. Monocultures are susceptible to pest
  attacks.
• Many major drugs come from tropical plants.
  Undiscovered drugs may be found.

44
Biodiversity as food base

• Plant species need to be maintained as a
  potential source of food.