Human Impact on Grasslands of Nose Hill, by Jason Ma

"You never know how precious something is until you finally lose it." This famous saying expresses how I felt after one of my research studies on the grasslands of Nose Hill. Although Nose Hill has an area of 11.3 km squared, it is one of the largest urban parks in Canada and in North America. This is horrendous in the fact itself. A natural area as small as 11.3 km squared is now the largest or second largest park on an entire continent! However this wasn't what gave me a sense of despair. It was during one of my Adopt a Park activities provided me with a realization of the devastation of human impact to the Nose Hill grasslands.

First of all, to give everyone a better understanding of the beauty and importance of Nose Hill's grasslands, let’s take a look at the wild life and vegetation. The grasslands were dominated by native plants such as Rough Fescue-Parry Oat grass, Rough Fescue - Golden Beans and Western Wheat Grass. As for the wild life, there were 151 species of vertebrate wildlife reported to occur in Nose Hill Park in 1993 conducted by Kansas Et Al. This list included 127 bird, 22 mammal and 2 amphibian species. Also it was noticed that native Rough Fescue grassland, are the primary breeding habitat for the largest number of bird species. Hence you can see there was great biodiversity in Nose Hill's natural ecology.

Nevertheless as the City of Calgary's population boomed, thousands and thousands of people now use and used Nose Hill as a recreation site. The magnificent Nose Hill Grasslands have and has been dramatically affected by human activities. It was recorded that as of 1997, an average of 5,426 persons per week visited Nose Hill Park during summer. It can be logically assumed that the numbers in 2010 are multiple times greater. These cyclists and dog walkers have and have caused the introduction of invasive species,

An exponential decrease in the population of wildlife species, fragmentation and alienation of rare habitats and finally higher mortality rates.

Currently the Grasslands occupied by native plants comprise of 452.8-ha which is 46.2% of the Park’s grasslands. The majority of the grasslands (53.8%) are now invasive or non-native grassland communities. These invasive species includes: Bluegrass (203.6-ha), Western Wheatgrass – Bluegrass phase (157.3-ha), Smooth Brome (114.8-ha), Smooth Brome-Quack Grass (43.1-ha), and Alfalfa-Wheatgrass (8.8-ha). It’s absolutely frightening that in less than a few decades of human interference that the primary vegetation in Nose Hill's Grasslands is composed of invasive plants from Asian and Europe. However whats worse is that anthropogenic introduction of this invasive vegetation has directly impacted the animals of Nose Hill. It has been noted that the lowest bird species richness was observed in non-native grasslands especially in the Western Wheatgrass –bluegrass phase plant community. Furthermore the invasive vegetation has brought destruction upon the natural fescue grass habitats, causing many species to relocate to other areas.

Another massive anthropogenic effect on Nose Hill was the habitat fragmentation as well as alienation that the rough trails cyclists and dog walkers made as they randomly roamed the Park. The creation of hundreds of trails around the park greatly disturbed the livelihood of natural wild life. Fragmentation of habitat occurs when large contiguous patches of native land are broken up into smaller, isolated pieces (Noss and Csuti 1997). Fragmentation can take the form of blocks of land or linear strips. These fragments of habitat render the wildlife to be immovable and subjected to isolation in its local area. This Initial exclusion occurs for species that occur only in the areas subject to development. These are usually animals with a very narrow distribution occurring in only a few patches of suitable habitat. Isolation

Of habitats through barriers to movement can then occur, effectively reducing habitat availability. In addition wildlife may avoid using habitat that is floristically and structurally intact because of the presence of human activity and associated sensory disturbance. This is known as habitat alienation. Due to habitat alienation and fragmentation, species like the Swainson's Hawk, Prairie Falcon, Peregrine Falcon, Short-eared Owl, Common Night Hawk, Sprague's Pipit, Baird's Sparrow, Long tailed Weasel, American Badger, Wandering Garder Snake and the Red-sided Garder Snake are now classified as scarce or rare. This isn't too surprising since bio indicators like the American Badger and the Sharp tailed Grouse, which are very sensitive to human disturbance hasn't been spotted for over a decade.

Finally another major problem that dramatically increases the mortality rate of wildlife is the dogs. As cute and loyal as our canine friends may be, they are incredibly troublesome in Nose Hill Park. They chase and disturb the natural community so often that almost all of the sensitive species of wild life has to relocate or face being chased to death. In fact some dogs will even kill and prey on little rodents such as mice and gophers.

After learning of all these terrible effects of human impact, my environment club and I decided to visit Nose Hill Park and do a litter pick up as part of Parks Calgary's Adopt a Park program. The litter pickup that day validated some of the habitat destruction and loss that people are causing. First off, there were fields and fields of invasive species. Then the thirty four students picked up over 60 pounds of trash in merely an hour! When I saw the overly stuffed bags of garbage, the disappointment and frustration was overwhelming. Yet this just comes to illustrate the disastrous effects human impact on Nose Hill. Despite the work the City of Calgary has been doing to minimize and mitigate the anthropogenic effects, we must all take action! Doing simple things such as being part of the Churchill Environment Club and going to the park to pick up litter or even just to educate your family and friends can accumulate to make a real difference.

Jason Ma

Check the actual blog at http://www.grasslands-nosehill.blogspot.com/

Grasslands

Nose Hill Park

Welcome to the group six blog on the grasslands of Nose Hill Park. Our main focus here will be to explore the influence that we as human beings have had on the park itself as an ecosystem.

As to be expected , public use of this natural park has had varying influences on its inhabitants both plants and animals. Over the years of being used publicly the park has undergone some noticeable changes. What once used to be an animal and plant sanctuary has not turned into a jogging and hiking location for those that live around it. Plant life and animals alike have made way for pathways and a man made pond. Due to the constant traffic of humans that flows through the park many of the plant life has been damaged severely. The pathways created for the ease of human travel have caused the death of grasses along the paths. Litter , which is not a major problem at the park but still an issue makes it that much harder for the growth of natural organisms.

The allowance of dogs in the park has caused mayor problems pertaining to the animal life. These dogs which are of leash in the are terrorize and kill the animal life in the area which causes them to stay away form the feeding areas used by humans. This intern affects the grasslands as no animals graze.

This has been meant to inform the public about the need to respect out natural parks.

Nose Hill Grassland Blog, by Wesley and Marina

            Nose hill Park is a very interesting and unique park to Calgary; it is the second largest park and will no doubt be affected by human impact over the years. It has been known to have diverse organisms in both plants and animals. Marina and I went to Nose Hill on September to research and collect samples. We noticed a lot of things about the park. First we made a transect (1mx10m; see Figure 1) to collect soil, biomass, plant and animal species to identify and test in the lab. A transect is an area that is made for studying a piece of land and everything inside of it. The climate was very dry and cold. The temperature we recorded was 16 degrees Celsius.

Figure 1.  A photo of the transect Marina and
 I created to research and take samples
for nose hill.

           The grassland biome is very exposed to the sun and sunlight can reach into the biome with ease. There is however an exception of how taller grasses and plants will out compete the smaller plants and shorter grasses. This is both an interspecific and intraspecific competition between the plants in this biome. This kind of competition exists because the taller grasses and plants will continue to grow and lean towards the sunlight for energy while the smaller plants are not growing and start to wear down and decompose. Speaking of decomposers we actually stumbled by a worm while I was collecting soil in our transect (see Figure 1). 

Figure 2.  Photo taken by Marina shows a
worm appearing when retrieving our
soil sample from our transect.

  




  

  
 
 
 
 
 
 
 
 
          Worms show that the area is rich in organic matter and valuable nutrients. Going back to the lab we did a soil profile and found out what exactly was in the water of the soil to see if it is normal and healthy. We found through many tests that the soil contained:

·       0.25mg/L phosphate

·       10. mg/L calcium

·       50 mg/L calcium carbonate

·       0mg/L ammonia

·       2.5mg/L Nitrate

·       pH of 5.0 (slightly acidic)

The soil chemistry indicates that first; the pH of the soil is pretty standard compared to other soils. The average pH for soil is around 5.0-8.0 pH. The nitrate and phosphate levels are very poor which contradicts the statement I made earlier on how healthy the soil is. But this could be due to the many sources of error when I was testing the soil sample in the lab. Firstly there is the human error, I could have read the instructions wrong, timing was inaccurate, forgot to shake etc. Second I noticed a portion of the tests were expired or really old which could have affected the result and outcome for the data. We retrieved the soil through the tool as shown in Figure 3. This tool allows us to see the different layers of soil and the characteristics of it. The soils temperature was 9 degrees Celsius.

Figure 3.  I’m collecting soil into a plastic bag
for further analysis in the lab. You can
observe the soils layer and how it changes as
it gets deeper.

 

Figure 3:

I’m collecting soil into a plastic bag for further analysis in the lab. Can observe the soils layer and how it changes as it gets deeper.

            Since nose hill park is the second largest park in Calgary it obviously going to be affected by humans. We humans have a big impact on this park and how it develops in the next generations.  The park is a great recreational area and good for hiking as well as walking dogs. The problem is when humans come in contact with the environment in a negative way such as littering, polluting and contaminating the park during their visit.

Figure 4.   A photo of a rotting and
decomposing banana we found near
our transect.

            I’m sure biologists and environmentalists would be upset when they see such a scene. Humans are the biggest contributing factor of whether Nose Hill Park can stay a healthy park or be damaged and polluted. Many different plant species were seen at the transect Marina and I created. Some of these species include:

·         Wild Rose (berries)

·         Prairie Rose (Rosa ark ansana porter)

·         Western Snowberry

·         Canadian Thistle

·         Squirrel tail

We did not find much living animal organisms we found in our transect other than the worm and a spider. The role or niche of the worm is to act as a decomposer. Decomposers feed on detritus which are waste from plants and animals, which also include their dead remains. The spider we found at nose hill was identified as a wolf spider which is a secondary consumer and its role is to feed on the primary consumers in the biome to keep their numbers low.

Public use of this park is changing the ecosystem and affecting the organisms. Humans, however, can be ecological friendly and leave a smaller ecological footprint by not littering or disrupting the food chain. This can be achieved without too much difficultly as long as humans are informed and educated. Humans decide the future of Nose Hill park and it is up to the choices of them for what will happen in Nose Hill. 

Forest, by Ali and Rob

Nosehill Ecology

         

Figure 1. This is a photo of Nosehill’s forest
ecosystem.

As a class we headed to Nosehill Park, located in northwest Calgary.  It was an intriguing experience as we all picked up some sort of knowledge in an indescribable way. Nosehill Park exhibits a variety of ecosystems. Along with the variety of ecosystems, Nosehill promotes biodiversity. Focusing on the Forest ecosystem, the biotic (living) and abiotic (non-living) factors provided an opportunity to observe and absorb the wonderful surroundings. The focus of our research was on the health of the forest.

            A few aspects led us to determine the state of the forests health. Soil samples played a major part in determining the soils health.

Figure 2. Table shows results from
soil testing. The soil sample

was collected from Nosehill
Park forest ecosystem.

It is said that “Forests are only as healthy as the soil they grow on.” (Macphail Woods Ecological Forestry et all..., 2010)The soil data strongly supports that the forest is not healthy as it can potentially be. The table shows that the forest soil contains low amounts of calcium. This data suggests that the forest is not at optimal health. Calcium is essential to plants in many ways, such as proper cell division and cell wall development. These processes require Calcium in order to keep various species of plants at their healthiest. Enzyme activity is fuelled by calcium, which is important for maintaining a healthy population of plants. An example of the importance of enzymes can be understood by the modification of isoflavonoids, natural plant products that help plants resist fungal infections. The pH of the soil also allows us to identify the health of the soil. A pH of 4 was recorded after a pH test, which was another indication that the forest was not at optimal health. A pH of 6-7 promotes availability of plant nutrients. However, Nosehill has an acidic soil structure, which creates obstacles for bacteria. Bacteria are vital for decomposition and the formation of healthy, fertile soil. Nitrate and ammonia are connected by processes in soil, and are very important in the development of healthy, fertile soil. All life depends on nitrogen fixation, a process where nitrogen gas is converted to ammonia. Without nitrate in the soil important processes such as cellular respiration cannot be performed. With the levels of nitrate at 2.5 mg/ L (ppm), and ammonia at 0.12 mg/L (ppm), Nosehill has a reasonable amount of nitrate and ammonia concentration, which is vital for life on Earth.

Figure 3.  A hand-drawn picture showing the

importance of soil bacteria resulting in the

nutrition of plants

The interactions and the diverse arrangement of species supported our research on the health of the Nosehill Park forest.



Figure 4.  Yarrow was found throughout the forest. Yarrow thrives in poor, dry soil, suggesting that Nosehill Park does not have the healthiest soil.



Figure 5. Wood’s Rose (Rosa Woodsii)

          A Wood’s Rose is a deciduous shrub that is capable of living in a variety of climates. Wood’s Rose prefer access to sunlight, but are able to tolerate shaded areas. The Nosehill forest does not provide the best living conditions for Wood’s Rose as canopy of foliage blocks some sunlight.         

Although the forest is not ideal for species such as Yarrow and Wood’s Rose, it does support other species. The forest has a diverse arrangement of species including insects, animals, and plants. This suggests that the forest is adequately healthy and allows for the development of various forms of life.

Figure 6.  An external view of the forest is
shown in this photo.

  With the data and observations recorded, we have questions regarding the treatment, lack of nutrients, and sub-optimal pH levels. Should urban planners take these signs as a cause of human development? Or are the changes a result of the natural course of these forests? The answers to these questions can help shape public policy regarding urban green space, or help obtain the most durable forests.

Visit the following website for more information

http://www.calgary.ca/portal/server.pt/gateway/PTARGS_0_0_771_203_0_43/http%3B/content.calgary.ca/CCA/City+Hall/Business+Units/Parks/Find+a+Park+or+Pathway/Major+Parks/NW+Parks/Nose+Hill+Park.htm

               

               

How Do Organisms Interactions in Nose Hill’s Forest by Caryna, Sarah, Livia, Eric, Kassy and Erin

Nose Hill Park is the second largest environmental park in Calgary, Alberta, with over 198 wildlife species identified on the hill. It is located in the northwest quadrant of Calgary. This park contains three ecosystems, ranging from a shallow pond to a populated forest area, as well as thick grassland. Plants and animals living on this land interact and compete amongst each other for food and habitat. They engage in both interspecific competition (competition between members of different species for resources needed to survive) and intraspecific competition (competition between members of the same species for resources needed to survive). Intraspecific competition generally occurs within a specific trophic level (a group of organisms that occupy the same position in a food chain) with organisms of the same species, while interspecific competition occurs within an entire food chain (the sequence of transfers of matter and energy from organism to organism in the form of food) as well as a specific trophic level – as long as the organisms in the trophic level are not of the same species.. Parasitism (a symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host), mutualism (a symbiotic relationship where both organisms of different species rely on one another for nutrients, protection, and other life functions), and commensalism (a symbiotic relationship between members of two different species of organisms in which one individual is usually only slightly benefited, while the other member is not affected at all by the relationship) also come into play. In the forest, animals interact with animals, plants interact with plants, and animals and plants both interact with each other in many different ways for many different purposes.

Figure 1.  Spider crawling on a sapling.

In the forest ecosystem at Nose Hill, there are many animals of different species with varying sizes. There are large animals, such as deer, smaller animals like ants, and many in between. For example, in an area measuring 0.5m X 0.5m, sixteen ants were crawling on the surface of the grass. Extending that area to a transect of 1m X 10m, one a spider was spotted wrapping a smaller insect in its web. Porcupines and mice have both been seen in the forest at Nose Hill, and for these animals to be able to survive; their food sources must also find a home in Nose Hill. Since all animals of every type of species in any ecosystem have to share food sources amongst their trophic level, this would be interspecific competition. An example of this in a forest would be Black Bears and the Swainson Hawk both vying for squirrels. Intraspecific competition in the forest would include two male Red Deer’s fighting for the attention of a female Red Deer to reproduce with. The Red-billed Oxpecker interacts with deer in a mutually beneficial relationship. The Oxpecker is a bird that eats ticks and other small insects off of the deer’s fur, providing the Oxpecker receives a source of food, and the deer in return gets a clean coat of fur free from ticks and other insects. Birds following army ant raids on a forest floor are an example of commensalism in the forest of Nose Hill. As the army ant colony travels on the forest floor, they stir up various flying insects. As the insects try and escape from the army ants, the birds following the ants catch the insects. In this relationship the birds benefit while the army ants are unaffected. Parasitism in a forest ecosystem is shown with an example of the cuckoo bird. The cuckoo bird does not build its own nest, rather deposits its eggs in the nests of other birds in the forest. The host bird then treats this new egg as its own, since the cuckoo throws an original egg out of the host’s nest so the host will not find a new egg strange. The egg count with remain the same. Once hatched, the newborn cuckoo bird can throw the host’s eggs and newborns from the nest. The cuckoo bird is the parasite in this example, and the bird whose nest the cuckoo is placed in becomes the host, as well as the eggs in the nest.

Figure 2.  A parsitic infection; red fungus on
bark.

Plant to plant interactions also occurs frequently in the forest ecosystem at Nose Hill. In an area

measuring 0.5m X 0.5m, two saplings were counted. Extending that area to 1m X 10m, there were seven saplings and ten smaller bushes counted as well as native grass.  These species of plants in forests, as well as many more, all compete for resources. If a tree species in a forest grows taller than surrounding tree species, it is able to absorb more of sunlight. This example of interspecific competition means that less sunlight will reach the trees that are shaded by the taller tree species. Intraspecific competition in the forest can be two trees of the same species growing close together. These two trees will compete for light, water, and nutrients in the soil. Mycorrhizal is a mutulistic association between plant roots and fungi that takes place in 80% of all plant species. The plan proves carbohydrates to the fungus, and the fungus returns the favour by providing the plant with phosphate and nitrogenous compounds. In this interaction, both the fungus and the plant are benefiting from the interaction, defining this as mutualism. Commensalism is also prominent in the forest ecosystem, with examples such as moss growing on trees. Moss is a plant that can have a commensal relationship with trees. The moss grows on the trunks or branches of trees, and receives light as well as nutrients that run down the tree. As long as the moss is not too heavy, the tree is not affected. Parasitism in the forest is closely related to an example of mutualism in the forest. Mycorrahizal is a mutulistic plant-fungi relationship, where as myco-heterotroph is a relationship very similar. However instead of the plant providing resources such as carbon to the fungus, myco-heterotrophs decide to take carbon from a fungus. The fungus becomes the host, and the plant species becomes the parasite. The parasite is benefitting from this relationship, and the host is being harmed and depleted of its carbon supply.

An animal interacting with plants happens frequently in ecosystems, especially in forest ecosystems. In an area measuring 0.5m X 0.5m, small insects, later found identified as mites, were crawling on the bark of a tree. The tree bark was spotted red due to this parasitic interaction. Extending that area to 1m X 10m, one owl was perched on the branch of a sapling tree. Interspecific competition occurs often between plants and animals in the forest, especially when large trees dominate the canopy. This allows little light to reach the animals in the forest, and the animals may have a harder time hunting their food source. Intraspecific competition, however, does not exist between plants and animals, since they are not of the same species. The Whistling Thorn plant and ants coexists in a relationship based on mutualism. The ants live inside the plant's thorns, and in exchange for shelter, the ants reduce competition for light from other plants by trimming back vegetation that would shade the Whistling Thorn from much needed sunlight. Since both the plant and the animal are benefiting from this relationship in the forest, the relationship is classified as mutualism. Commensalism in the forest takes place in many different ways. Plant seeds are moved by animals to other areas of the forest. For example, buts and other stick-tight seeds gather on the fur of animals as they brush past, and when the animal roughly brushes past an obstacle, the seeds fall off and eventually begin to grow into a new plant. Since the animal is not harmed by moving the seed, and the generally seed is moved to a place with little competition for nutrients, light, and water, this relationship is known as commensalism. Mites make a habitat in forests, and seem to find their homes in the bark of trees. The tree bark then begins to have red patchy spots on it, and although the red spots do not seriously harm the tree and leave when the mites leave, this interaction is still classified as parasitism.

Figure 3.  Transect ares measuring
 1 m X 10 m.

                Animals interact with animals while plants interact with plants, and these two different living entities also interact with one other. Nose Hill shows how these organisms interact in different ecosystems, and the in the forest it provides visual examples of the different types of interactions and how they positively or negatively affect the organisms in question. Regardless of the nature of the interaction, a relationship between organisms keeps the forest in Nose Hill consistent with how it has been for decades. Both intraspecific competition and interspecific competition keep the forest from becoming overpopulated, while mutualism, commensalism, and parasitism contribute to the diverse population that is able to thrive in Nose Hill’s forest.

Bio Mini Lab for Nose Hill (Lab in Vodcast)

Problem: What effect does the number of consumers in an ecosystem have on the amount of producers that are consumed?

Hypothesis: If the number of consumers in an ecosystem increases, then the amount of producers that are consumed will decrease, because a higher number of consumers mean that there is a higher need for food.

Materials:

-3 clear plastic cups

-9 leaves of similar size, and identical species

-20 ants

-1 square foot of saran wrap

-3 rubber bands

Procedure:

1.       Number the cups one, two, and three

2.       Place three leaves in each cup

3.       Cover the opening of cup one with saran wrap and secure it with a rubber band

4.       Poke five small holes in the saran wrap

5.       Place five ants in cup two

6.       Repeat steps 3 to 4 with cup two

7.       Place fifteen ants in cup three

8.       Repeat steps 3 to 4 with cup three

9.       Leave cups indoors for three days

10.   On the third day, observe and record the amount of producers consumed in each cup

Observations:

	Cup 1 (No ants)	Cup 2 (5 ants)	Cup 3 (20 ants)
After 3 days	No change	No change	Small amounts nibbled off from the sides of the leaves.
After 7 days	No change	Small amounts nibbled off from the sides of the leaves.	Approximately a quarter of the leaves were consumed.

Sources of Error:

-Sizes of leaves may be inconsistent.

-Ant’s appetite size and preference may differ

Conclusion:

From our data collected, we have observed that the higher amount of consumers there are in an ecosystem, the more producers will be consumed.

Blog References

1.       EverythingBio. Life Science Glossary. 2005. Web. 23 Oct. 2010. <http://www.everythingbio.com/glos/index.php>.

2.       "TreeHelp.com: Trees: Diseases." Treehelp.com - Tree Care Made Easy. Web. 23 Oct. 2010. <http://www.treehelp.com/trees/trees-diseases.asp>.

3.       Copyright Nearctica.com, Inc. "Nearctica - Ecology - Population Ecology - Commensalism." Commensalism. 2004. Web. 23 Oct. 2010. <http://www.nearctica.com/ecology/pops/commens.htm>.

4.       "Symbiosis in the Forest." Web. 23 Oct. 2010. <http://web.fccj.org/~dbyres/mutualism.html>.

5.       "Competition." Marietta College. 2008. Web. 23 Oct. 2010. <http://www.marietta.edu/~biol/biomes/competition.htm>.

6.       The City of Calgary. "The City of Calgary: Nose Hill Park." 2010. Web. 23 Oct. 2010. <http://www.calgary.ca/portal/server.pt/gateway/PTARGS_0_0_771_203_0_43/http;/content.calgary.ca/CCA/City Living/Facilities and Programs/Parks/Natural Environment Parks/Locations/Natural Areas in NW Calgary/Nose Hill Park/Nose Hill Park.htm>.

Vodcast References

1.       Learn Science at Scitable." Nature Publishing Group : Science Journals and Information. Web. 26 Oct. 2010. <http://www.nature.com/scitable/knowledge/library>.

2.       "Mutualism." Encyclopedia of Earth. Web. 26 Oct. 2010. <http://www.eoearth.org/article/Mutualism>.

3.       Dictionary.com | Find the Meanings and Definitions of Words at Dictionary.com. Web. 26 Oct. 2010. <http://dictionary.reference.com/>.

4.       "Interactions of Organisms." Oracle ThinkQuest Library. Web. 26 Oct. 2010. <http://library.thinkquest.org/CR0210243/Science Station/How living things interact with their environment/interactions of organisms.htm>.

5.       "Predator-Prey Relationships." The Global Change Program at the University of Michigan. Web. 26 Oct. 2010. <http://www.globalchange.umich.edu/globalchange1/current/lectures/predation/predation.html>.

6.       "Tree Infections - EHow.com." EHow | How To Do Just About Everything! | How To Videos & Articles. Web. 26 Oct. 2010. <http://www.ehow.com/tree-infections/>.

7.       "Commensalism." The Department of Biodiversity & Conservation Biology - UWC. Web. 26 Oct. 2010. <http://www.bcb.uwc.ac.za/Sci_Ed/grade10/ecology/symbiosis/commen.htm>.

Podcast References

1.       "TreeHelp.com: Trees: Diseases." Treehelp.com - Tree Care Made Easy. Web. 23 Oct. 2010. <http://www.treehelp.com/trees/trees-diseases.asp>.

2.       Malmstrom, Carolyn M. "Ecologists Study the Interactions of Organisms and Their Environment | Learn Science at Scitable." Nature Publishing Group : Science Journals, Jobs, and Information. 2010. Web. 23 Oct. 2010. <http://www.nature.com/scitable/knowledge/library/ecologists-study-the-interactions-of-organisms-and-13235586>.

3.       Advameg, Inc. "Competition - Biology Encyclopedia - Body, Examples, Different, Organisms, Specific, Types, Water, Produce, Role." Biology Reference. 2010. Web. 23 Oct. 2010. <http://www.biologyreference.com/Ce-Co/Competition.html>.

4.       "Behaviour - How Does Interspecific Competition Affect Organisms?" Biology Revision Online. Web. 23 Oct. 2010. <http://www.easyscience.co.nz/ubbiology/behaviour/lesson3.htm>.

5.       TurorVista. "Interactions Among Organisms | Tutorvista.com." Tutorvista.com - Online Tutoring, Homework Help for Math, Science, English from Best Online Tutor. 2010. Web. 23 Oct. 2010. <http://www.tutorvista.com/biology/interactions-among-organisms>.

Human Interference and the Forest by victoria, David and Fejiro

How does human interference in abiotic factors affect the biotic factors of the forest ecosystem at Nose Hill?

By Victoria, David, and Fejiro

An ecosystem is comprised of many different aspects. Within abiotic factors are temperature, water, soil, and many others, while biotic factors include biomass, biodiversity, and food webs. Each part of an ecosystem is linked to every other part, which makes an ecosystem a unit that functions as one. If one factor changes even slightly, it can alter everything else in the system. Biotic and abiotic factors are constantly changing, but a big cause of change in natural areas can be human impact. When looking at Nose Hill Park, situated in Calgary, Alberta, it is obvious that the same is true for its ecosystems. Nose Hill Park is predominantly grassland, but also has extensive forest areas. These forest areas have their own particular characteristics that define them as ecosystems, and because the park is located in the middle of a large city, it can be assumed that humans have impacted the forests of the park in more than one way. By analyzing various factors and comparing them with other related research, we can discover exactly how humans have affected Nose Hill Park of Calgary, Alberta, Canada.

            Temperature plays a large role in the type of ecosystems that can exist in a region and what those ecosystems are like. In Alberta, which is primarily situated in boreal forest and grassland biomes, temperatures can range from 30°C in the height of summer to -30°C in the depths of winter. Because of these rather severe seasons, organisms must be adapted to survive in both the warm and cold months. In the forest of Nose Hill Park, there are many deciduous poplar trees, shrubs and wildflowers which inhabit boreal forest regions. There is also an abundance of grass found on the hills of the forest, even though it is not in the grassland part of the park. During the winter, trees are of course less active. During the other seasons, trees work to store water and nutrients to survive the winter. As for other leafy plants, many of them die in the winter and return in the spring, since the individual plants cannot survive the harsh temperatures but instead can reproduce each season. Animals are also affected by temperature; hares and coyotes, for example, develop thicker winter coats to insulate body heat while ground squirrels hibernate in the tunnels they have built underground. Although humans do not impact temperature directly or acutely, a well-known human impact on the environment is global warming through greenhouse gases. Greenhouse gases have a larger potential to affect Nose Hill Park because it is situated in the middle of a city where carbon dioxide is constantly being emitted due to industrial and domestic pollution in large quantities; these pollutants will affect local areas first. Greenhouse gases get trapped in the atmosphere and absorb heat, increasing the atmospheric temperature. This results in a slow increase in temperatures worldwide. Even slight temperature changes can drastically impact an ecosystem because organisms are accustomed to a particular climate and often do not have enough time to adapt to changes in that environment. As atmospheric temperatures increase, the types and populations of organisms in the Nose Hill forest could easily change. Organisms who survive in cooler climates may see decreases in populations which would decrease the biomass of the forest. Biodiversity would also decrease because many organisms would either be eliminated from the forest or migrate further north to a climate more similar to what they are adapted to. 

            In forests, having an abundance of available water in the ecosystem is crucial. Because trees require large amounts of water (they transpire more than other plants due to their size and must maintain a large water supply for functioning), regular rainfall and adequate ground water is very important. A main characteristic of forest ecosystems is the amount of water (grasslands have noticeably lower amounts of water) because it is required to sustain the types of vegetation and animals that are a part of that ecosystem. In the Nose Hill forest, a soil sample was found to contain 40.7% water. The canopy cover at the Nose Hill forest was rather sparse since the trees tended to grow upward as opposed to outward, so the amount of evaporation from soil and transpiration from plants will be higher. Because of this, it is a good thing that the forest has an adequate percentage of water in its soil.

            Ever-present in a forest is evapotranspiration. Evapotranspiration is the loss of water through evaporation from soil and transpiration from plants (Biology-Online.org, 2005). The chemistry of the forest depends on evapotranspiration; this is especially true at Nose Hill where the facing of a slope is crucial to the evapotranspiration, and therefore to the entire forest. Most of the forested areas at Nose Hill are along north-facing slopes. In the Northern Hemisphere, the rate of evapotranspiration tends to be higher on south-facing slopes. This is because, following the path of the sun, north-facing slopes have morning sun while south-facing slopes have afternoon sun, and in the afternoon, the heat from the sun tends to be hotter than in the morning. The hotter an area is, the more evapotranspiration is going to occur (water will evaporate into vapour from the soil, while plants will lose more water in the heat to transpiration). Therefore, it makes sense that most of the forests at Nose Hill Park tend to be on north-facing slopes; the sun they receive in the morning is less intense heat-wise than the sun they would receive in the afternoon on a south slope. On a north-facing slope, they will lose less water through transpiration, and there will be less water loss from the soil. Water is a limiting factor for the growth and survival of trees, so trees will survive better in areas where the water content is higher and there is less transpiration (Bachman, 2004). However, just because this is a natural occurrence doesn’t mean that human impact isn’t involved. Global warming is once again affecting environments everywhere, and Nose Hill is certainly no exception. If climate change continues at its current rapid rate, higher temperatures worldwide will result in higher rates of evapotranspiration. Since the forests at Nose Hill Park are already accustomed to the specific temperature conditions in Calgary, rapid rates of climate change will only negatively impact the situation. If the amount of evapotranspiration on even north-facing slopes becomes too much for the trees in the forest to handle, it may very likely result in the trees failing to survive, which will lower the biodiversity in the forest and impact the rest of the food chain in the forest ecosystem.

Soil content is a main factor in the health of a forest. It can dictate what the health of the plant life is, and therefore what the health of the animal life is. However, just as soil majorly affects an ecosystem, an ecosystem can majorly affect soil. Soil provides water, nutrients, and stability to plants, which all transfers to the organisms in the next level of the food chain. For example, the pH level of the Nose Hill forest soil is 5, which is good because healthy pH levels in boreal forests are found to be slightly acidic (USDA Forest Service, 2008). Trees adapted to a low pH can often have difficulty surviving in soil that is too alkaline (basic) because it can result in deficiencies of key nutrients such as iron (Buchdahl, 2004). With acid rain, we see the negative effects of high amounts of water in the soil. Acid rain (precipitation containing harmful amounts of nitric/sulphuric acid formed by sulphur oxides and nitrogen dioxides released into the atmosphere during fossil fuel combustion) acidifies the soils and waters where it falls. The more water there is in the soil of an area, the more likely acid rain is to dissolve in that water and enter the food chain through the root uptake of plants (Buchdahl, 2004). Because Nose Hill is situated in the middle of a city, the possibility of it being directly impacted by fossil fuel combustion is high. Industrial sources in the city, such as factories and power plants, emit large amounts of CO₂ (which contributes largely to global warming) and can release other harmful substances into the atmosphere, such as those that contribute to acid rain.  However, returning to the idea of slopes, the slope of the hill on which we set up our forest transect was quite steep (see Figure 4). During precipitation, some of the water that falls on the forest is partly absorbed into the ground water supply, while some of the water travels down the hill as run-off. Because of the rather steep slope of the hill on which the forest is situated, it is likely that much precipitation will not enter the soil and ground water of the forest and instead travel down the hill. In this way, the slope of the hill helps to protect the forest from absorbing too much acid rain too quickly. This in turn benefits the biotic community of the forest because it means healthier soil, healthier plants, healthier animals, and an overall healthier ecosystem.

Nose Hill Park is a stubbornly natural area amidst suburbs, cars, and skyscrapers, and despite Calgary’s efforts to keep Nose Hill unaffected by human impact, that is an impossible goal. There will always be factors indirectly affecting the ecosystems of Nose Hill, and the forest ecosystem in particular. Nose Hill is a fragile place and must be guarded by the City of Calgary, but there is only so much we can do. In truth, the way to change what is happening to the park and dozens of other natural areas all over the world lies not just in local actions, but global actions. Each person’s decisions influence the global environment. If people begin to take responsibility for their decisions and work towards a healthier natural global community, it would not only benefit the plants and animals of Nose Hill Park; it would benefit every park and every person in every location anywhere in the world.