Monday, November 22, 2010

The Nose hill Park Grasslands; A Journey of Discovery

Peter and Kevin
October 28, 2010
Figure 1. Grasslands on Nose Hill park. 

Nose Hill Park is a biological symbol of the city of Calgary. The park is surrounded by 12 communities is covers over 11 square kilometres. Surrounded by 4 major roads, there is a sharp contrast between the subtle beauty of the natural grasslands and the rowdiness of the city streets leading to the tall skyscrapers in the distance. Nose Hill Park has been preserved ever since the 1980’s in the northwest quadrant of Calgary; it is one of the largest municipal parks in North America. This shows that Calgarians do care about the ecology in our area and want to preserve this land for future generations. By examining the grasslands of this area, we learn about biochemical’s cycles, interactions, organisms and human impacts. We can apply the knowledge to the conservation Nose Hill Park in the future. 
Figure 2.  Sign introducing Nose Hill.
Of course going to this park was not just a spur of the moment sort of thing. Careful planning had to be done to make our investigation a successful one. The weather, clothing, instruments, materials must all be considered. What we brought with us were cameras, soil corers, shears, string, stakes, hammer, shovels, and many plastic bags for samples.
On September 20, 2010, my partner and I set off from Sir Winston Churchill High School to the wilderness of Nose hill Park. The wind was blowing after a large rainfall, we could still feel a light drizzle. Of course, we still went anyways. We prepared ourselves and entered Nose Hill’s vicinities.
Figure 3.  Our group at the grasslands.

On a cold wet cloudy day, my partner and I trudged our way through the depth of Nose Hill Park. As we walked down the dirt path, the smell of fresh air and rotting feces filled our nostrils.
            Weary from our trip, we reach our destination. To our left were the vast grasslands; to our right was a dense forest. Of course, we knew ahead of time that the grasslands were our destination. We scaled the hill; our pants got wetter and wetter as we reach our target.
            We examine the area and set up our simple 10 meter by 1 meter transect. Within the artificial boundaries of our transect was a myriad of life. At first glance, all one could see was grass; tall grass short grass, you name it.  Some of these species include: snowberries, asters, wild roses, False Solomon’s Seals, and smooth bromes. With such a rich assortment of biodiversity, we hoped to uncover more about why so many plants can grow in our little transect.

Figure 4.  the grass within our transect.
            After our initial observations, we decided to take some in-depth data. In the cold September weather, the temperatures at a meter above the ground were consistent 0.5°C. While temperatures 5 cm below the soil had respective temperature of -0.1°C, 0.0°C, 0.9°C, 0.0°C, and -0.2°C. The fact that temperatures beneath the ground were colder than temperatures above ground appalled us. We wondered why this would be. Perhaps, water was frozen beneath the ground, or maybe the soil is poor at retaining heat. We actually still can’t verify why this is.

Figure 6.  A second soil correr sample.  Our transect is in the background.

Figure 5.  Grassland soil core sample.
 To further examine our transect we took some soil samples using our soil corer. With limited success, we pulled up two samples. From our samples we could see that the just topsoil extended at least 20 centimeters. The soil from our samples was pretty consistent in their content. It had high humus content as well as decomposing organic matter, as well and some unrecompensed filler. We assumed that this soil composition provided a great abundance and verity of nutrients for the plant.
Figure 7.  Soil characteristics and testing.
Further testing of the soils somewhat backed our initial assumption about the nutritional potential of out soils. We dug a 50 by 50cm pit, 20 cm deep and collected the soil for testing. During this process we found multitudes of earthworms as well as the odd spider. The soil sample was going to be tested for ammonium, ph, phosphates, iron, calcium, and nitrates.

Figure 8.  Drawing of a Berlese funnel used to extract soil arthropods.
Figure 9.  Soil sample in the Berlese funnel.
The soils were tested by testing the possible nutrients that may have dissolved into distilled water after filtering a distilled water and soil mixture. Each nutrient was tested 5 times. The results were as follows. Ammonium had an average concentration of 2.6ppm, phosphates had an average of 0 ppm, iron had an average concentration of 0 ppm, Calcium had a average concentration of less than 20ppm, and nitrate had an average concentration of 2ppm. 
From these tests we could tell that two essential products from the process of nitrogen fixation and nitrification were present. Ammonium and nitrate are the basic essentials of plant growth. The abundance of these nutrients may explain the variety and abundance of plant life in these grasslands. However, we could not find existing data on the nutrient levels grassland soils so no comparisons could be made.  Of course the decomposers like the earthworms probably helped the soil to get to this state. With so much plant life, the soil must depend on the decomposition of dead plants for its nutrients.
Water was found on average to make up 13.3 percent of the soils mass. This was done by finding the mass of 50g of soil after it was dried. The difference in mass must be the water that was evaporated. Organic material was also found to make up about 15.4 percent of the mass of the soil. Again, this was done by drying the soil, submerging it in water and collecting the debris that floats to the surface. The debris (organic material) is then dried and weighed again. Again, no reliable values could be found to compare this data. Therefore, it cannot be determined if a soil in this state is more beneficial or detrimental to plant growth. However, we can infer that this soil composition if beneficial due to the fact that there was such an abundance of producers in the ecosystem. 
We had one last test for the soil before moving on; and that was the Berlese funnel. Any animals in our soil sample should fall into the methanol so escape the heat of the light, or so we thought.
However, after two trials, only specs of dirt fell down the beaker. Perhaps our soils did not host as much life as we thought. Although, one has to consider that the soil was left in a Ziploc bag for a week.

Figure 10.  Arthropods on the Erlenmeyer flask after
24 hours in the Berlese funnel.
Figure 11.  Conversions of biomass to energy.
Of course, there was more to our transect than just soil. To increase our understanding of the ecology of our transect. We gathered all the bio mass in a 0.25m2 area. Our dried producer biomass was 133.44g, our decomposer (a worm) biomass was 2.38g, and our consumer’s (an aphid and dwarf spider) biomass was 1.78g. In total this came to be 137.60g or biomass per 0.25m. According to this ratio, there should be 5504.00kg of biomass per hectare. 
From the previous data, we can also find the energy in the biomass of the various organisms. If one calorie is equivalent to 4.18 joules, and there is 1.5kcal/g in animal tissue and 4.23 kcal/g in leaves, the energy in 133.44g of plant/leaf tissue is 2359.41kj. The energy in the worm, spider, and aphid combined is 26.08kj. Such a disparity in energy supports the idea of highly inefficient energy transfers in a ecosystem 
We can also calculate that there are 40000 aphids, worms, and spiders per hectare of grasslands. However these calculations are likely to be completely inaccurate due the fact they are likely to be more consumers in our sample area but they were just too hard to spot.
In total there is 2386.21kj of energy per 0.25m2. According to this ratio, there is 95 448 400kjof energy per hectare.
From what we found in our transect, a food web can be produced as shown in figure 12.
Figure 12.  A food web for Nose Hill grassland.
The species on the first row include: snowberries, asters, wild roses, False Solomon’s Seals, and smooth bromes
            From the species found in this web, we can only conclude the existence of interspecific and intraspecific competition and predation Various plant species compete other species for the space. This suggests interspecific competition. However these species also compete with other in their own species; suggesting intraspecific competition. Finally, aphids ingest the various producers and he spider eats the aphids. These are fine examples of predation.
 Unfortunately, due to the lack of time and availability of species, this food web is likely a small fraction of the actual food web of the nose hill park grasslands.
            And that concludes the part 1 of 3 part series on the ecology of the Nose Hill Park grasslands. We have observed many different species of plants and animals and found many quantitative relationships in our little transect. Tune to our podcast for the 2nd instalment of the Grassland Ecology of Nose Hill Park: The Transfer of Energy!

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