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6.2.2.b
Terrestrial ecosystems are dealt with first in this section. Scroll down for Part B on aquatic ecosystems.
Natural ecosystems will be affected by a changing climate. The list below was made by scientists who have been studying the Great Lakes basin for many years.
Implications of Climate Change on Natural Ecosystems
- Biological productivity is expected to increase with moderate temperature increases.
- Zoo-geographical boundaries move in a changing climate.
- Introduction of invasive species could be exacerbated.
- Existing community structures and interactions may change.
- A changing climate is expected to lead to reduction in some habitats.
- Wetland vegetation communities, functioning, and values may change.
Source: International Joint Commission (IJC) Climate Change and Water Quality in the Great Lakes Region. May2003 www.ijc.org
ACTIVITY 1
1. State what each of the 6 possible impacts listed above means in your own words.
2. Use one local ecosystem and describe the changes that climate change will bring based on this list of changes for natural ecosystems. Hint: Check this website for special references to temperature, precipitation, hydrology, and ecosystems.
A changing climate has a direct impact on the health of ecosystems. If the climate warms in Canada, the range and distribution of vegetation will change. The temperate forest zone, for example, will move towards the north. Soil conditions would limit the rate of forest migration, however. Existing trees are likely to be stressed by weather change before they ever migrate. Note that natural ecosystems are the basis for human health.
As ecosystems are disrupted, some members of the ecosystems will move north, but others will stay. Invasive and colonizing species will move first; sensitive species will not be able to move. Some wildlife and fish populations will become extinct.
Source: Environmental Signals National Environmental Indicator Series, Environment Canada (2003) http://www.ec.gc.ca/soer-ree
ACTIVITY 2
1. What was the number of endangered or threatened species and subspecies populations in Ontario ecozones in May 2001 for Hudson’s Bay? Tundra? Boreal? Southern Ontario mixed forest? Total?
2. What changes have been made to the list since this date?
3. What percent of Ontario is less than strictly protected? has 100% protection?
ACTIVITY 3 Research
The boundaries of the ecosystems seen here will be shifting northward with increased temperatures due to climate change.
Find the new locations of these present ecosystem boundaries in 2050 or 2100 and redraw this map. Hint: some scenarios have done this.
Terrestrial and aquatic ecosystems should be studied for changes in biodiversity, productivity, boundaries, and the arrival and distribution of exotic and invasive species.
The maps below show first the present forest family diversity and then, below, the predicted diversity of forest tree families under a doubled concentration of carbon dioxide. Some scenarios show that tripling of carbon dioxide concentrations should be also considered. Adaptation and mitigation programs need to be planned now for these conditions. Some of the changes predicted for later in the century have already been observed in 2004. See also the past, present and future for ppm of global CO2.
Don MacIver (2000) Forest Families, Forest Biodiversity Integrated Assessment Mapping Project www.utoronto/imap
ACTIVITY 4
At the bottom of the above legend locate the color for forest families at Windsor.
1. What percentage of tropical families did Windsor trees represent in 2000?
2. What is the percentage for Sudbury area family diversity?
Note: There are 4 more whole forest families represented in the southern area.
Source: MacIver, D. C. and H. Auld (2000). The Changing Atmosphere: Forest Biodiversity and Productivity in Ontario, Canada. 14th Conference on Biometeorology and Aerobiology, 14-18 August 2000, Davis, California. 260-261 pg.
ACTIVITY 5
1. Locate the “Windsor” color on the 2xCO2 map. Name the largest city in that area.
2. What percentage tropical are the “Windsor” forest families to become under these conditions? Compare this with the present forest family diversity map found above this one.
3. Where did the species shown in light colours come from?
ACTIVITY 6 Research
What species are typical in Carolinian Canada? In North Carolina USA?
Increases in global temperature increase the instability of our climate and weather systems. Increasing instability of our climate and weather systems affects the amount, the timing, and the intensity of precipitation, whether rain or snow.
Changes in temperature and water availability will cause Ontario ecosystems to undergo change. These increases will affect species presently found or cultivated in natural, agricultural and managed forest ecosystems. Native species will be under additional stress from invasive or introduced species better suited to these new conditions.
Wildlife is susceptible to climate change. Rare and endangered species may be more vulnerable as habitats are reduced though climate change. Wetlands will be especially vulnerable to changes in species as less water is available along with warmer temperatures.
Climate change and variability will also impact agriculture in the Great Lakes region, as well as forests, recreation, and tourism.
The chart below features the scientists’ literature search for papers that have been published on fish and wildlife habitats that are relevant to the work on preparing for climate change. These are the research findings for item number 1 on the list of impaired use benefits mentioned in earlier sections. Italics indicate if it is directly related to impacts of climate change on the Great Lakes basin. Normal type shows the findings outside the Great Lakes basin to show the further range of climate change impacts.
Source: International Joint Commission (IJC) Climate Change and Water Quality in the Great Lakes Region. May2003 www.ijc.org
ACTIVITY 7
1. What is the range of years that the research was published? Earliest to latest.
2. What topics of research would you add to this list?
3. Where would this research be found?
4. What can you contribute locally to this research?
See the PAST Section 4.1e for an Ontario sample of post-glacial pollen core analysis. The rate at which succession occurred at this location is seen through the layers in the pollen core over time, especially when compared to other sites.
A 500 km northward shift in climate over the next century will be faster than vegetation can migrate. Following the last glacial period, 12,000 years ago, maximum tree migration rates averaged from 10 – 40km per century. White spruce had a peak rate of 200 km per century. Present woodlots, unable to keep pace with climate change, will be more likely become too stressed to survive and native biodiversity will be lost.
Temperature is one of the key factors that determines whether a species can live in the climate of a new region. Two other factors are considered in the chart below. A basic understanding of the parts of a leaf in cross-section, photosynthesis, and respiration is needed here. More advanced science studies are needed to understand the workings and the role of the physiological processes listed in below.
Source: International Joint Commission (IJC) Climate Change and Water Quality in the Great Lakes Region. May2003 www.ijc.org
The interactions of species in food chains and struggle for homes in ecosystems will be affected by climate change. This is because the rates of movement of plant and wildlife populations are different.
Wildlife boundaries are moving northward at a faster rate to the cooler habitats the wildlife prefer. Timing changes in insect outbreaks, such as the spruce budworm. change each insect’s place in food chain of the forest community. New food chains influence the biodiversity of the forest.
Warmer temperatures are also expected to expand the ranges, shorten the outbreak cycles, and enhance the survival rates of forest pests, such as spruce budworm and the mountain pine beetle. Insects have short life cycles, high mobility, and high reproductive capacity, all of which allow them to quickly exploit new conditions and take advantage of new opportunities.
Native species in Ontario’s forests are adapted to their local climates. The warmer the climate the greater the number of tree species found in the forest ecosystems. Forest species will become more heat stressed. See the forest family vs. Growing Degree Days (GDD) graph below. Ontario forests show a potential shift in the species range limits under global warming climate conditions. Some species are already showing increased diseases due to heat stresses and changes in precipitation such as wet springs. For example, red maples have mildew outbreaks.
Increased frequency and severity of fire, drought, disease, and infestations will add more stress to native forest species. Disturbances may interact by accumulating- that is that increases in one type of disturbance increase the potential for other types of disturbances. For example, in the boreal forest of western Canada an increase in spruce budworm outbreaks could increase the occurrence of wildfires, especially in drier regions.
Forest biodiversity increases linearly with growing degree-days (GDD) from the poles to the tropics.
Diversity of Present Mixed Hardwood Forest Families in Ontario, 2002.
ACTIVITY 8
1. Find a map of Ontario with degrees latitude. How many degrees latitude does Ontario cover? What is the southernmost point? The northernmost? Check against the graph above and find the average number of tree families represented in each 2 degrees of latitude.
ACTIVITY 9 Research
1. Use the graph showing the number of forest families and the Corn Heat Units (CHU) map below for southern Ontario. How does this compare with GDD graph? What is the basic difference in measurement protocol for these units? Determine the correlation between these two units.
2. Check out the www.carolininancanada.org for species details. Confirm your prediction by checking on the web – Ontario Ministry of Natural Resources, Canadian Forestry Service, Agriculture, etc.
Southern Ontario Average Annual Corn Heat Units (CHU)
Corn Heat Units are based on air temperatures in degrees Celsius. This accumulated value is calculated using the following conditions:
1. Start-up of corn growing season: where the mean daily temperature is> 12.8 oC for three consecutive days during the period May 11 to July 31.
2. End of the season: the first occurrence when the minimum daily temperature drops below -2.0 oC during the period August 1 to October 15.
Southern Ontario Average Annual Corn Heat Units (CHU)
Source: Watson and MacIver (1995) Integrated Assessment Mapping Project www.utoronto/imap
ACTIVITY 10 Questions
1. This is the southernmost part of Ontario and of Canada. What is the range of latitude shown?
2. Check the area shown against the land cover and CHU map of agricultural use in Section 5.2.1 Ecosystems.
3. Check with the map in Section 5.2.1 showing loss of original wetland area. What does correlating these 3 maps explain?
ACTIVITY 11 Research
1. What is the correlation with the hardiness zone map used by gardeners and foresters.
2. List 3 implications of climate change impacts for 3 each of agriculture, natural vegetation, and Ontario’s economy.
3. What are the implications for the species at risk Canada? See the map at the top of this section.
New forests accumulate carbon very slowly as seen in the graph below.