BIO 1070 – Term Test 2 Notes
Biodiversity: refers to the different scales of biological variation
Species richness number of species present in a defined area such as a community or
Species abundance how common a species is in a defined area
Abiotic factors are the physical and chemical features of an environment. Abiotic factors
include light (radiation), temperature, water (availabilty, composition, flow), atmospheric
gases (including pollution), and soil factors such as nutrients and porosity
Biotic factors refer to the living things that live within and shape an ecosystem. Includes
producers (plants that convert the sun’s energy into chemical food), consumers (organims
that eat other plants and/or animals) and decomposers (organisms such as bacteria or fungi
that feed off dead biota, decomposing large organic molecules into smaller units).
Population: A populations refers to the colllection of individuals of a single species within a
defined area at a specified point in time.
Community: A community refers to the collection of species (each with its own population)
living in a given area at a particular point in time. Community ecology is the study of the
structure and dynamics of animal and plant communities.
Ecosystem: An ecosystem is a community of organisms that interact with each other and
environmental factors (e.g., abiotic factors). Ecosystem ecologists focus on the investigating
processes that influence the composition and distribution of organisms. This includes the
transfer of energy and cycling of nutrients.
What is a forest/woodlot?
-different species and layers of trees
-canopy, sub-canopy, shrub layer, moss etc.
Population growth is defined as the change in the number of individuals during some
period of time. This is calculated using demographic data; population growth rate = birth rate
– death rate + immigration – emigration. The calculation of population size is expressed as
Pt2 = Pt1 + (B) – (D) + (I) – (E)
Carrying capacity is defined as the number of individuals that can be survive on the
available resources within a given area. It is not fixed as it can be altered by disturbances
that deplete resources.
Species Interactions: Different species that live in the same ecosystem/community interact
in many different ways
Types of species interacitons:
Mutalism: Both species benefitted
Competition: Both species have a negative effect on each other
Predation/Parasitism: 1 species harmed the other benefits
Commensalism: Species 1 is benefited, but species 2 is neither benefitted nor harmed.
Amensalism: Species 1 has a neg