Discussion

2. From what we observed, there were 4 groups of producers. They were algae, thistle, grass and trees. Algae are the food base for the organisms that live in the pond such as zooplankton. Thistle and grass are eaten by white tailed deer. One of the dominant species of trees is the trembling aspen. Rough fescue parry oat grass is the dominant species of grass.

3. Competition and Organisms
One of the main adaptations, which we witnessed while we observed the Nose Hill park pond was the grass and the shrubs both growing together within the pond. Both these plants compete for sunlight within a certain amount of area. Because of the competition for sunlight the tall grass grows taller using length to attract the sunlight, while the shrubs and shorter grass spread out more using area.

Summers at Nose Hill Park include a variety of different birds and amphibians. It is during the summer, when these birds go on their hunting spree capturing and consuming their prey. The most common snake in western Canada would be the Garter snake. It is most commonly hunted by both the Northern Harrier and the Hawk. Both these birds compete within each other’s territory in order to capture the snake. Hunting strategies vary, from airborne reconnaissance to perching in likely spots and watching for movement below. Only quickest and most skillful bird can capture its prey for dinner

Another form of competition within Nose Hill Park is between the Coyote and the Long Tailed weasel. Both mammals have a similar diet and live very close to each other. They both have a central diet of rodents such as mice, squirrels and rabbits. The Coyote and the Weasel both have a smaller body similar to a dog and each with four strong legs, which help it run fast and allow them to catch the small prey. These characteristics are needed in or these characteristics are needed in order to catch the pray. They also both have a long nose which helps when they are digging into their prey's body looking for meat. These mammals are adapted in such a way, in order to hunt efficiently and quickly.

4. We didn’t observe any symbiotic relationships while we were at the park. In the deer that live in the park, mutualistic gut fauna exists which helps them digests plant matter. One of the dominant parasites at nose hill is leeches. They form a parasitic relationship with organisms in and around the pond. 

10. Human Impacts

There are significant archaeological sites in the park including stone circles. These were formed by using stones to hold down the edges of tipis and are called "tipi rings." Because of its height, the hill was also a sacred place used for ceremonies and burials. European settlers began using the area in the late 1800's for farming and ranching. Large areas of the plateau have been ploughed large areas of the plateau have been ploughed and planted to agricultural crops. Some of these areas are being returned to native grassland.  There is an old gravel pit on the plateau which is slowly being reclaimed by nature. In the 1980's, much of the park was destined for residential development. However, vigorous citizen action saved the land for the magnificent park we have today. Over the years, the impact of weekly visitors to Nose Hill Park, now numbered at 5,500, have destroyed the wildlife habitat there. More than 300 kilometers of informal trails have developed and their heavy use has contributed to the loss of important species such as sharp-tailed grouse and badger. Nose Hill is home to more than 130 bird species and 25 mammals but many of them are in decline, including Baird's Sparrow and Western Meadowlarks. The City of Calgary has put a revival plan into action and will start making trials for visitors to use while visiting the park. This way the decline of species may slow down.

 

Near the North facing slope the nitrate level of the water was 10 mg/L which is fairly healthy considering there needs to be a concentration of 20 mg/L of nitrates or more to be toxic for fish and other organisms.  Most of the nitrates where likely from run-off entering the pond but some of them were from plant and animal wastes and decaying organic matter.  The level of nitrates near the south facing slope was most likely slightly lower because there was less algae near the south facing slope.  Nitrates are important nutrients for plant growth so there will most likely be more nitrates in the water where there are more plants because the plants need the nitrogen to grow.

 

We were unable to get an acurate test for the level of phosphates in the pond.  The phosphate level was likely slightly above 1 mg/L, which is when algae growth begins to significantly increase, or around mid-level like the nitrates because it would have been brought into the pond by run-off and also from decaying organic matter.  The level of phosphates near the south facing slope would likely be slightly lower than the level at the north facing slope because, like the nitrates, it is an important nutrient for plant growth and there was less algae near the south facing slope.

 

The mid-level of nitrates and phosphates probably promoted the growth of algae in the pond.  The level of nitrates and phospahates might also have caused the low level of dissolved oxygen in the water by the south facing slope.  By promoting the growth of algae it could have cause an algal bloom which leads to greatly decreased levels of dissolved oxygen in the the water.  There weren’t enough nitrates in the pond to cause a full algal bloom but it did cause an increased growth of algae along the shoreline of the pond.  The level of nitrates also might prohibit the type of organisms that live in the pond, as only less sensitive organisms will be able to live in the pond because of the mid-level of nitrates.  Highly sensitive organisms won’t be able to survive in the pond because the nitrate levels will be too high for them and cause toxic affects.

 

The pH level near the north facing slope was 6.7 which is pretty low considering most fish can survive in water with a pH level from 6.5 to 9.0.  Near the south facing slope the pH was likely slightly lower because there was a very low amount of dissolved oxygen in the water meaning that there were a lot of organisms using oxygen and therefore giving off carbon dioxide  which lowers the pH.  The pH of the water can be directly altered by the amount of dissolved carbon dioxide in the water; the more carbon dioxide there is in the water, the lower the pH will be because the carbon dioxide mixes with water to form weak carbonic acid.  There was probably such a low pH because all the algae and decomposers create a lot of carbon dioxide during the night, which greatly reduced the pH of the pond, and the algae hadn’t had enough time yet that day for photosynthesis to remove enough of the carbon dioxide from the water to make it more basic.

 

The low pH level makes it difficult for most organisms to survive because they try to regulate the pH level in their blood so that it is similar to the pH level of the water.  Only less complex organisms or organisms that are more adapted to livng in water that is more acidic will be able to live in the pond because of it’s relatively low pH level.  Algae levels in the pond should continue to increase because very few organisms are able to survive in the water and therefore the algae won’t be consumed as quickly and will continue to flourish.  This will lead to an even lower pH of the pond in the morning because the algae produce lots of carbon dioxide during the night and a farely high pH in the evening because the algae will have been using carbon dioxide during the day for photosynthesis.

In the pond near the north facing slope the dissolved oxygen level was 6.8 mg/L or ppm which is fairly high considering the average range for dissolved oxygen levels in water is 3 to 10 ppm and cold water fish need about 7 ppm of dissolved oxygen in order to survive.  Near the south facing slope the dissolved oxygen level was -0.3 ppm.  The dissolved oxygen level near the south slope was likely negative because the conditions of the pond were most likely slightly different than what the probe was standardized for so it read the level as a negative.  The level of dissolved oxygen in the water was probably low so the probe read it as a negative.  Also there was a large density of algae in the water which would block sunlight from penetrating the surface of the water causing most or all of the other photosynthetic organisms that grow under the water’s surface to die.  This would cause an increase in number of decomposers in the water who would greatly lower the amount of dissolved oxygen in the water because they would feed on the large amount of dead organic matter in the pond.  Runoff to the pond also would have brought large amounts of nutrients such as nitrates and phosphates into the pond as well as a large amount of decaying organic matter.  This would promote large amounts of algae growth and also cause large growth of decomposers.  The decomposers would create a very high biological oxygen demand greatly lowering the level of dissolved oxygen in the pond.

 

The high level of dissolved oxygen in the water near the north facing slope will be able to support a large number of organisms and could potentially support most species of warm water fish, which need about 5 ppm of dissolved oxygen in order to live, and possibly some species of cold water fish, which need about 7 ppm of dissolved oxygen to live.  Many organisms could live in this area because there is plenty of dissolved oxygen for them to be able to carry out cellular respiration and other essential activities.

 

The extremely low level of dissolved oxygen near the south facing slope will most likely cause most of the organisms in that area to die because there is no oxygen for the organisms to use for cellular respiration.  The death of large amount of organisms including plants will cause a huge increase in the number of decomposing bacteria.  The decomposers can survive with very little oxygen and because of all the dead organic matter they will flourish.  As the decomposers eat and break down the organic matter from the organisms that have died and from the run-off, they will use oxygen, further reducing the level of dissolved oxygen.  This will cause even more organisms to die and therefore the decomposers will continue to flourish while the level of dissolved oxygen will continue to decrease because there are more decomposers and less autotrophic organisms that produce oxygen.

Figure 1: Food Chains

Little-seed/Rice Grass ► Barid's Sparrow ► Garter Snake ► Swainson's Hawk

Canadian Rice Grass ► Long-Tailed Weasel ► Red-sided Garter Snake ► Prairie Falcon

Sandhills cinquefoil ► American Badger ► WAndering Garter snake ► Peregrine Falcon

Chickweed ► Sprague's pipit ► Short-eared owl ►Common Nighthawk

Along with Food chains we were able to make up a small Foob web showing different patterns and the diversity in Nose Hill