Transcript Temperature Effects on Upper Latitudinal and Elevation Limits

Forest Ecology
What is forest ecology?
Study of
– Relationships between organisms and their
environments
– Interactions of organisms with one another
– Patterns and causes of abundance and
distribution of organisms in forests
What forest ecology is not
From Gurevitch et al. 2006
Organisms and Their Environment
Climate – temperature, precipitation, etc.
– Note the importance of how these variables are
measured and expressed
Soils
Light
Interactions and combinations
Niche – the range of conditions in which a species
can survive; i.e., where a species’ traits allow it to
successfully interact with its environment
Examples of Niche
Sugar maple
Jack pine
Larch
Sugar Maple
Jack Pine
Larch
What happens when niches overlap?
If there aren’t enough resources to meet the
optimum amount for each individual,
competition will occur, resulting in
– Reduced growth rate for one or both or
– Mortality to one of the competitors
In many situations, the species will have
developed ways to minimize competition, such
as
– Get their nutrients and water from different depths
in the soils
– Flower at different times relative to leaf
development
Trillium
Trilliums flower early, before the hardwood
trees above them leaf out – thus giving them
time to flower before it is too shaded
Forest Communities/Ecosystems
All the species of plants and animals
interacting with
– One another and
– Their environments
Examples
Spruce-Fir
Northern Hardwoods
Forest Changes
Disturbance and Succession
– Forests are always changing due to
Disturbances
Plant growth and mortality
– Examples of disturbances
– “Recovery” after disturbances
Examples of Disturbance - Fire
Examples of Disturbance - Wind
Disturbance Example - Harvesting
Succession
Changes in species composition, structure,
and processes following a disturbance
Those changes will be driven by the
environment and biota
Harvard Forest dioramas illustrate a typical
sequence of land changes from clearing
during settlement to land abandonment
when agriculture in New England went
down hill (for multiple reasons)
Harvard Forest Dioramas
Harvard Forest dioramas illustrate a typical
sequence of land changes from clearing
during settlement to land abandonment
when agriculture in New England went
down hill (for multiple reasons)
Presettlement Forests
1740 - Early Land Clearing
1830 - Height of Cultivation
1850 - Land Abandonment
1910 - Harvest of Old-Field
White Pine
1915 - Hardwoods Follow Pine
Harvest
1930 - Hardwoods Reach Cordwood
Size
Old-Field Succession