Inquiry Case 4
• Urban forests are critically important to the maintenance of
biodiversity, the water quality and the overall health and quality of life
for all species living in that space.
• Brown’s Woods
o Brown’s woods is a small woodlot (1.31 hectare (ha)) but has
importance that is not predicted by its size. By following the
link below, you can read about the history of Brown's woods as
written by emeritus professor, Doug Larson.
• North Campus Ravine
o Brown’s woods is a small woodlot (1.31 hectare (ha)) but has
importance that is not predicted by its size. By following the
link below, you can read about the history of Brown's woods as
written by emeritus professor, Doug Larson.
o The other dominant tree species is the native early succession
species, Manitoba maple (Acer negundo).
• The Arboretum
Inquiry Case 5
• The Edge effect –
o Forest fragments have a long history of study - in particular
how there is a difference between the quality of habitat
between interior habitat and habitat closer to the edge.
o There was a particularly useful review of the principal effects
that an "edge" has on forests
, BIO 1070 MIDTERM INQUIRY CASES
• Abiotic Factors: there is differential movement of solar radiation,
temperature, humidity, moisture, and wind between interior and edge
habitat. Edge habitats often become intermediate between the two
adjacent habitats (e.g. between forest and field, the forest edges
become hotter and drier with solar radiation than the interior)
• Access: when resources are spatially separated and edge
provides access to both resources.
• Species Interactions: many incidences of increased nest predation
for birds nesting in edge habitats.
• Population Growth:
o Population growth is defined as the change in the number of
individuals during some period of time.
o This is calculated using demographic data; population growth
rate = birth rate – death rate + immigration – emigration.
o The calculation of population size is expressed as Pt2 = Pt1 + (B)
– (D) + (I) – (E)
▪ Pt2 is the final population at the final time
▪ Pt1 is the original or starting population size
, BIO 1070 MIDTERM INQUIRY CASES
▪ B is the number of births
▪ D is the number of deaths
▪ I is the number of immigrants
▪ E is the number of emigrants.
• Carrying capacity
o Carrying capacity is defined as the number of individuals that
can survive on the available resources within a given area.
o The carrying capacity for any landscape area is not fixed as it
can be altered by disturbances that deplete resources.
o The depletion of resources is often accompanied by a
decrease in population size.
o As the environment is degraded, carrying capacity actually
shrinks, leaving the environment no longer able to support the
original number of individuals in the population that may have
been sustained for many years.
o No population can live beyond the environment’s carrying
capacity for very long.
• Species Interactions
o Different species that live in the same ecosystem/community
interact in many different ways (see table below).
Note: that some mutualisms may be either obligate (must live
with it’s partner species) or facultative (can live without its
partner species). Community structure includes the species and
their abundances within a specific area and includes different
types of interactions (chart 1)