Transcript Ecology and Conservation

OptionEcology and
Conservation: G1 Community
Ecology
Outline the factors that affect the distribution of plant
species including temperature, water, light, soil pH,
salinity, and mineral nutrients
*High temperature denatures enzymes and retards growth of
plants; the rate of transpiration (loss of :water) is also increased.
*Low temperatures decrease enzyme activity and freezing
temperatures inactivate enzymes
• Water is needed for enzyme activity, transport, photosynthesis,
support, and many other things.
• Light is important for photosynthesis and flowering
• Soil pH is important for absorption of nutrients.
• Salinity has an affect on the absorption through osmosis. High
salinity causes plants to lose water through osmosis.
• Mineral nutrients are needed for many vital functions. Nitrogen
is needed to manufacture proteins, enzymes, nucleotides,
vitamins, and other compounds. Phosphorous is used in the
formation of phospholipid and DNA.
Explain the factors that affect the distribution of animal
species including temperature, water, breeding sites,
food supply and territory
• Temperatures affect the concentration of animals.
Cold-hot tolerances.
• Water is needed for vital functions, so only animals
that can conserve water are found in deserts.
• Breeding sites are needed for growth and
protection of young. Some need specific areas to
breed.
• Food supply is important for survival since animals
are heterotrophs.
• Some animals are territorial and need large areas
for feeding, mating, and protecting their young
Describe one method of random sampling, based on quadrat
methods, that is used to compare the population size of two
plants or two animal species
• A sample = part of a population/area
• In a random sample every individual has
an equal chance of being selected
• Quadrats = sub-sample sizes, within your
sample area
Quadrats, Points and Line (Transect Sampling)
Pop size estimate = mean # of org/quadrat
(x) the total # quadrats in sample area
Niche Concepts
• Niche Concept – the mode of existence of
a species in an ecosystem
• Habitat – where species live in an ecosystem
• Nutrition – how food is obtained
• Interactions/relationships – predator-prey,
competition, symbiosis
• Competitive exclusion principle
• Realized niche - actual
• Fundamental niche - potential
Outline the use of a transect to correlate the
distribution of plant or animal species with an abiotic
variable
Explain what is meant by the niche concept, including an
organism’s spatial habitat, its feeding activities and its
interactions with other species + distinguish between
fundamental and realized niches
Outline the following
interactions between species,
giving two examples of each:
competition, herbivory,
predation, parasitism and
mutualism
Competition – two individuals (intra) or two
species (inter) using the same resources
(food, habitat, mates)
• Terrestrial ex.
• Aquatic ex.
Species Interactions – Herbivory: a
primary consumer feeding on a plant or
other producer.
• Terrestrial ex.
• Aquatic ex.
Predation – consumers feeding on
consumers
• Terrestrial ex.
• Aquatic ex.
Parasitism – when an organism
feeds on a host without killing it.
• Terrestrial ex.
• Aquatic ex.
Mutualism: +,+ relationship between
members of two different species
• Terrestrial ex.
• Aquatic ex.
Explain the principle of competitive exclusion
• First proposed by Lokta and Volterra, competitive
exclusion takes place when two species need the
same resources, and will therefore compete until one
species is removed.
Define biomass & describe one method for the
measurement of biomass of different trophic levels in an
ecosystem
• Biomass is the dry weight of organic matter in
organisms of an ecosystem.
• Measuring biomass is a destructive sampling
technique, so the samples used are as small as
possible.
• Representative samples of all living organisms in the
ecosystem are collected, for example from randomly
positioned quadrats.
• The organisms are dried, by being placed in an oven
at 60-80°C.
• The mass of organisms in each trophic level is
measured using an electronic balance.