Monday, December 6, 2010
Both the secondary and tertiary consumers are known as heterotrophs as they do not produce their own food. This food pyramid shows examples of predation as the respective organisms are killing and consuming the organisms in the trophic levels below them. In contrast parasitism does not kill either of the organisms, for example a mosquito (parasite) bites a passerby (host), the mosquito benefits from receiving blood for nourishment and the human suffers from pain and blood loss. In addition we found that the PH of the water was 6.5, indicating a slightly acidic but nearly neutral level – these conditions are hospitable to many life forms and therefore support a wide biodiversity within the pond and with that a greater multitude of organisms. Oh the mysteries of ecology.
As with many grasslands,
was once used for ploughing, the planting of crops, and keeping of cattle. Although it has been decades since these actions were implemented on the park, the effects are still seen today. Early actions by humans have shaped the park since before its creation in the 1980s and even before then when the European settlers and Aboriginal people of Nose Hill Park used the land. Canada has restored itself fairly well since its days of abuse (ranching area has returned to native grassland and natural flora and fauna species have also returned), but now the park is facing other kinds of issues. First, there is the concern of global warming. Grassland areas all over the world are slowly being converted to deserts because of temperature increases in the global climate, which reduce the already low water supply of these areas (grassland biomes receive up to 150cm of precipitation less than boreal forest biomes) (Bourne, et al, 2004). If precipitation levels get too low, combined with increased evapotranspiration due to higher temperatures, there is the potential of grassland destruction. Since global warming includes all biomes, Nose Hill is definitely affected by this trend. Using a 45.75g sample of soil from the Nose Hill Grassland, we found that the soil was 19.3% water. This is a significantly lower value than the water content we measured for the Nose Hill forest, which was 40.7%. From this data we can infer that the grassland uses and requires less water than the forest. This is due to the fact that grasslands tend to be drier than forests through evapotranspiration (they most often cannot support trees, which require large amounts of water), and evaporation of water from the soil is most likely to occur in the grassland because the ground is not as sheltered from the sun, which triggers increased evaporation due to increases in Nose Hill Park temperature, as the forest (trees can block sunlight from reaching the forest floor, therefore preventing extensive water loss from the soil). The amount of water in the soil also helps to explain why Nose Hill is mostly grassland, with small forest communities. Due to the level of precipitation that receives, as displayed in Figure 2, our climate can more easily support grassland ecosystems as opposed to forests. As previously mentioned, forests require a much higher amount of water which is not always available due to low precipitation levels. Therefore, the majority of natural areas in southern Calgary are in fact grasslands. Now, how does this all relate to human impact? The effects of global warming tie in nicely with precipitation levels and water content. As the temperature of the atmosphere increases from trapped greenhouse gases that absorb heat from the sun, worldwide levels of evapotranspiration (the loss of water through evaporation from soil and transpiration from plants) will increase while precipitation will decrease (Biology-Online.org, 2005). A serious threat to the grassland due to these elements is that it may become even drier and eventually turn into a desert. Then, it would not be able to support even the limited biotic community that it does as a grassland. Alberta
Nutrients are a very limiting factor to the types of organisms an ecosystem can support. A noticeable fact about the Nose Hill grassland soil is that it has a rather low phosphate level of 0.25ppm. Phosphate typically comes from two sources: the weathering of sediments and fertilizers. Therefore, from the evidence of a low phosphate level, we can infer that this is either due to a lack of sediments or rock in the Nose Hill grassland (any sediments present would be buried under the soil, and rocks/mountains do not have a direct impact on the grassland), or to a lack of industrial sources of phosphate (fertilizers in particular). This is good because it indicates that the grassland has not been largely impacted by fertilizers, despite run-off from domestic sources in the city such as people’s lawns. However, it is also important that the soil contains some phosphate, as it is essential to root growth in plants and is needed for the transfer and utilization of energy in the bodies of animals (Chase, et al, 1999). The small concentration in the grassland soil can be seen as something positive because the amount is not so high that it saturates the soil and supports the extensive growth of weeds and other pests which can result in interspecific competition (a simultaneous demand for resources within an ecosystem that occurs between individuals of different species) (Biology-Online.org, 2007).
The pH of the grassland is also an indicator of the soil content of the area. The grassland was found to have a pH of 6, which is slightly more basic than the forest pH of 5. The acidity or alkalinity of soil can be affected by the concentration of calcium in the soil; the more calcium there is, the more basic the soil will tend to be (
, Collister, 2006). This information leads us to believe that the level of calcium in the grassland soil is higher than the level in the forest because it is more alkaline. Since the forest and grassland are adjacent to one another in the park, it is likely that they share the same or similar abiotic characteristics. However, since they are classified as being different biomes and therefore ecosystems, differences between them will always exist, no matter how close they are to one another. Kansas
Of the abiotic factors composing climate, wind is a significant one in a grassland. Winds tend to be faster in grasslands because of the open space as opposed to in wooded areas where trees and larger plants can block wind and therefore slow it down. Since Nose Hill is a vast park that consists mainly of grassland, wind speeds can be much higher on the hills than in the rest of the city. Nonetheless, the wind tends to be impacted by the city of
. Urban morphology (the form, function, and layout of a city and the study of these features) can significantly affect the intensity and patterns of wind flowing around and above cities (Hang, J., et al, 2008). Therefore, wind disruptions caused by the infrastructure within the city can impact the grassland community. Some plants are better adapted to windy areas than others, with deep, strong roots to anchor themselves and prevent stress caused by the inability to absorb water and nutrients from the soil if roots are tugged and pulled by the plant swaying in the wind. As the city of Calgary Calgary continues to grow and engage in more construction, this can indirectly impact the grasslands of . The grasslands may have problems adapting to changing wind patterns caused by the growth and expansion of the city that surrounds it. Nose Hill Park
The health and vitality of the grassland at
is a delicate balance, mostly due to the fact that the natural area is in the middle of a large city. Its location contributes to its vulnerability as a sustainable environmental community, and the struggle to keep Nose Hill natural will continue on into the future. Some of the impacts on the grassland are ones that we in Nose Hill Park can help prevent, such as littering, while others are bigger than us, such as climate change. For the benefit of all natural grasslands (as well as other ecosystems), a global effort is required to keep the environment as in-tact as possible. There will always be pollutants and changes in the environment, but that doesn’t mean that we humans can’t do everything in our power to help these ecosystems that are incapable of helping themselves. By analyzing the factors that influence the biotic and abiotic aspects of the Nose Hill grassland, we can determine what there is to be done about keeping the grassland at an optimal state and work on plans of action in terms of this natural maintenance. Calgary
Figure 1. A sign in front of the pond
in Nose Hill. It shows a map of the
park and describes the rules of the park
The focus of this blog will be onthe aspects of the pond located at an altitude of 1152 meters above sea level, at latitude of 51.6°, 6.59 minutes north and a longitude of 114°, 8.31 minutes west. The pond is a stormwater wet pond and is home to many insects; however a flock of ducks also calls the pond home. Organisms that were confirmed to be present due to being collected as samples include, freshwater shrimp, mayfly larvae, damselfly larvae, leeches, caddisfly larvae, snails, phantom midges, predacious water beetle larvae and water boatmen (which are a type of diving beetle).
These organisms were observed under a few conditions, the first one being at 9:50 AM at nosehill pond, when we had just collected the first sample. They were not very active and interacted very little with their surroundings (we placed aquatic plants with them, which were later used as more samples). The second time the organisms were observed was when we collected another sample of different organisms from the same section of the pond. The only difference between these two samples was a temperature change of about 2.5°C. However, in the second sample, the organisms were observed to be much more active. They interacted with each other, as well as with their environment much more than the first sample. The final time the organisms were observed was in the lab. The lab was about 21°C, which is about 13 degrees warmer than the warmest temperature recorded at nosehill. Both of the organisms from our first sample and our second sample were observed at this time. These organisms exhibited hyperactivity, despite being a in a plastic bag for over 4 days. They interacted with their surroundings very actively, as well as with each other.
Clearly the data collected in the observation above says something significant about the effects of temperature on organisms. The temperature is directly linked to the amount of activity from collected organisms. Since the lighting was about the same for the entire session at nosehill, and the lighting at the lab is about as bright as the lighting at nosehill on the day we performed our research, temperature remains to be the only strong factor for these observations. The tables below show data collected about the temperature of the pond during the early morning of September 22, 2010.
Water Temperature (°C)
Ground Temperature (°C)
Air Temperature (°C)
Table 1. Average temperatures taken at different times in the morning
Ground Temperature 30 cm from water (°C)
Ground Temperature at edge of water (°C)
Ground Temperature 15 cm into water (°C)
|Figure 3. A photo of ducks at Nose Hill pond.|
The higher the temperature, the more active all of the animals were. This did not change for any of the species observed. Keep in mind that the organisms did not have a sudden spike of activity the moment the temperature hit a certain level. They became more active over time, eventually shifting from passively hiding in the grass to actively interacting with their surroundings. They did not have equal reactions with the surroundings either. Some organisms did not have large reactions when the temperature changed,
Figure 4. A photo of a salamander that was
found at Nose Hill park.
considerably. This occurred when it was brought into the lab and was warmed up. It moved at over 3 times the speed that it was moving at when it was found at nosehill park. Other species, such as the damselfly larvae, did not have such a large reaction to temperature. Although it did become more active, it did not begin moving at 3 times its pace while cold.
Another observation that was noted was that the population of the organisms in the first sample we collected, compared to the second sample that was collected was that there were about 3 times the amount of organisms in the second sample (the one collected at a warmer temperature), than in the first sample (the one collected at a colder temperature). This is probably related to the activity of the organisms and is definitely an important factor in our study.
As the observations suggest, temperature has a large effect on the way organisms behave. Higher temperatures increase both the amount of activity from the organisms and the population of them, while lower temperatures decrease these values. The amount of species that can also be seen also increases as the temperature increases. Temperature changes have the ability to change the way an ecosystem behaves by altering the behaviour of predators or prey, as well as changing the population of the ecosystem. This is a very important factor in the reason why an ecosystem behaves in a certain way and should definitely be studied to a degree that is much higher than the one that this study has performed.
Due to the large area covered by Nosehill, the terrain from one section can differ greatly from that of another. This allows many different ecosystems to exist. Our focus would be on the forest area within Nosehill. Though the forest area appears to be very similar to the rest of Nosehill at first glance, many differences exist to allow the forest to strive. The differences that will be compared will be mainly focused on soil contents and pH levels. Soil samples were collected at the edge of the forest, 10 metres into the forest, and in the grasslands. 1.00 gram of soil was then taken and mixed with 100mL of diluted water.
The soil content is very useful in the identification of possible reasons to why the forest only exists in one area. Ammonia in soil can cause the soil to acidify. A test showed that the Ammonia contents were the lowest at the edge of the forest with a 0.3mg/L. However, results show that it was the most acidic with a pH of 5.5. The Ammonia contents was much higher in the grassland and 10 metres into the forest with 0.9mg/L and 0.6mg/L respectively, but the pH at both of these two locations were only 6.
Phosphate is essential in the growth of plants. The Phosphate contents both inside the forest and at the edge were 1.00mg/L. The Phosphate content in the grassland area was close to doubling that amount with 1.75mg/L. This is to be expected because trees require much more phosphate than the low shrubs and grasses that grows in the grassland. If the consumption of the Phosphate was taken into consideration, the Phosphate reserve in the forest should much higher than that of the grassland.
Calcium exists in adequate amounts in most soils. It is also essential to plants as it is the substance which is responsible for Nitrate uptake and metabolism, enzyme activity, as well as various other functions within the plant. Inside and at the edge of the forest, Calcium contents exist at the level of 300mg/L and 400mg/L respectively. The Calcium contents in the grassland showed similar relative ratio as Phosphate, with a level of 1080mg/L. Once again, this did not come as a surprise because of the same reason as Phosphate.
Nitrate is another substance which is essential for plant growth because it is a basic component in proteins. Nitrate, nitrite, amides, free amino acids and small peptides make up the most of the part of the Nitrate in the plants which does not form into proteins. The Nitrate contents at both inside and edge of the forest were surprisingly low with 0.0mg/L in both areas. The content level was slightly higher in the grassland with 10mg/L.
Iron is a micro nutrient for plant, this means that although it is required by the plants, it is only in small amounts. The iron contents were quite low in all three areas. It is only 0.1mg/L inside the forest and at the grassland. It is 0.0mg/L at the edge of the forest.
Some other observations made inside the forest area include, species of snowberry shrubs can be found at about a 28/m² density. Grasses can be found at about a 320/m² density. Aspen trees can be found at about a 1/m² density. Saplings of Aspen trees can found at about a 0.8/m² density. From that information, it can be concluded that the forest area is currently at the stage between Shrubland and Young forest in the Succession progress. The area was also in a sheltered dip between two hills. Little to no wind is found within and around the area. Because of these factors, it can be concluded that almost no erosion occurred to the soil in that area. High levels of moisture are also found within the forest area. However, this may be caused by weather conditions.