Wednesday, November 30, 2011

Grassland Interactions by Andrea and Sophie

Psychopaths, Predators, Prey and Samaritans by Sophie
            One could spend eons of time marveling at the cornucopia of organisms in the grasslands of Nose Hill Park and yet not know everything about them for it is one thing to be able to identify these organisms and another to understand the interactions between them. Organisms depend upon each other and nature depends on them. This blog highlights the kinds of interactions between grassland organisms, looks at the succession of these organisms and of the grasslands of Nose Hill park itself and compares them to the forest and pond biomes as well as Edworthy Park.             Firstly, what is an interaction? An interaction is the quality, state or process of (two or more organisms) acting on each other (Hallworth, 1988). There are many kinds of interactions, and a pair of signs denotes them, such as (+/-), to symbolize how an interaction affects the population of the involved organisms. Let us take a look at interspecific interactions- relationships between the species of a community (an assemblage of populations in an area or habitat).
Commensalism is a +/0 interaction that benefits only one of the species involved while the other species is unaffected. One such example is the Buffalo Bean (Astragalus crassicarpus), also known as the Ground Plum, which produces a plum-like fruit 20mm in diameter, with dry “plums” of previous years stashed away by Ground Squirrels as a food source. The Buffalo Bean is not harmed and Ground Squirrels receive nutrients. Foxtail Barley (Hordeum jubatum) is a grass with fruit that each have 4-8 barbed awns that attach to animals and clothing. It benefits for it regenerates by prolific seed production while transporters of awns are otherwise unaffected.

Mutualism is a +/+ relationship where both species involved benefits, for example the process of pollination, in which bumblebees transfer pollen from the anthers to the stigmas of Bebb’s Willow (Salix bebbiana). The willow is able to reproduce and the pollinator, the bee, attains pollen to meet its energy requirements and to produce offspring. Another example is dung fungus, such as Panaeolus separatus and Stropharia semiglobata, which fruits on mammal droppings. This provides a food source for animals that eat mushrooms, such as rodents, and allows the fungus to thrive.

Predation is a +/- interaction in which an organism (predator) captures and feeds on another organism (prey), thus benefiting one organism while the other suffers. Some prey adaptations such as camouflage, or cryptic coloration, makes them difficult to be spotted against their surroundings. Protective coloration is when species camouflage (make themselves blend in with the environment that they live in) by their color, so that their predators don’t see them. (Campbell, N. & Reece, J., 2002).  Prairie long-tailed weasels, which prey on Hares, Ground Squirrels, Voles and Mice, turn white in the winter to camouflage with their white surroundings and are snuff-brown in the summer. The Ammophilia spp. (thread-waisted wasp) is a predator that consumes a caterpillar (prey) and assassin bugs eat other bugs by stabbing them with their proboscis and injecting a toxin that dissolves their tissue, which they ingest. The Pterostichus melanarius preys on caterpillars, species of beetles, aphids, weevils, and earthworms. Mourning Cloak and Anglewing butterflies (+) lay their eggs on the buds of Willows, Poplars, Nettles and Gooseberries (-) and also use them as food sources.

Parasitism is a +/- symbiotic relationship (any relationship where two species live closely together) between an organism (parasite) that lives inside or on another organism (host) and harms it by obtaining nutrients from the host. Fleas and mosquitoes (parasite) feed on the blood of Richardson Ground Squirrels (host) and mammals in general. The Ammophilia spp. (thread-waisted wasp) uses caterpillars as storage sites for its larvae by stinging and paralyzing the caterpillar, then burrows it, lays an egg on it, and seals the burrow.

Interspecific competition is a  -/- interaction as conflict exists between two or more different species that rely on the same limited resource, including food, water and resting sites. Pasture sage (Artemisia frigida) and broomweed (Gutierrezia sarothrae) are unpalatable plants, leading to them increasing on overgrazed areas of Nose Hill. This creates competition with other species of plants, such as prairie sage (Artemisia ludoviciana), for the land and causes soil erosion. Another example is Marasmius oreades, the Fairy Ring Mushroom, which is constructed from mycelium. It grows in rings that originate from a spore and the mycelium makes the soil of the outer ring nonwettable and droughty, causing conflict with Tulostoma simulans for water.

Intraspecific competition a -/- relationship in which conflict between individuals of the same species arises for a resource that is in short supply. Paradigms of this are assassin bugs for when there is nothing to eat, they compete to eat each other.

Batesian Mimicry is when a harmless species (mimic) copies a harmful species (model) in order to trick predators into keeping their distance from them. The White Admiral or Red-spotted Purple (Basilarchia arthemis rubrofasciata) is a mimic of the poisonous Pipevine Swallowtail (Battus philenor) with its black with iridescent blue hind wings.

Müllerian mimicry is when each species is harmful and resembles the other while serving as a model. The Robber Fly, which has saliva with enzymes that paralyze and digest the insides of its prey when it injects it into them, mimics wasps, which have a powerful sting.

Comparisons to the Pond and Forest Ecosystems of Nosehill

Commensalism is found at the pond between marsh wrens and cattail plants. The marsh wrens build their nests on the stalks of cattails, gaining shelter from predators, but do not affect the plant itself. This is an instance of commensalism because the organisms that are using primary producers as protection gain because they stay safe and the primary producers do not gain or lose anything. Another example of commensalism found is between damselfly and dragonfly nymphs and pondweeds. The nymphs hide at the bottom of the pond among the pondweeds, allowing them safety and camouflage from predators as well as the ability to surprise and attack prey. In turn, the nymphs affect the pondweeds neither positively nor negatively. In the forest, commensalism can be seen when lichens grow on the higher branches of aspen trees. As lichens grow on trees, they receive their needed nutrients, and are able to grow and reproduce. While this benefits the lichens, it doesn’t benefit nor harm the branch or the tree that the lichen is living on. These interactions echo those of the grasslands, in which an organism gains a food source while the other is not impacted, however, roles of protection and reproduction are not mentioned.

At the pond, fungus and algae exemplify mutualism. Fungus provides a tough, waterproof body able to withstand extreme environments on rocks, being good at obtaining water and secreting acids to dissolve minerals from the rocks. It also produces carbon dioxide. All of these materials are then provided for the algae, which use them in photosynthesis to produce sugars, which are then shared with the fungus. Another example is between algae and freshwater snails, where the algae find substrates on the shells or carapaces of the snails, which in turn benefit from the camouflage. At the forest, bumblebees take pollen from flowering plants to make honey for themselves and spreads it to other plants. Both fungi and bumblebees are involved in mutualism at the grasslands.

In the pond ecosystem, the main predators found are the Pond Wolf Spider (Pardosa pseudoannulata), Harvestmen (Opiliones), damselfly and dragonfly nymphs and adults such as the Aeshnidae, Water Boatman (Corixidae), Predacious Diving Beetle (Hydaticus modestus), Flatworm (Dugesia polychroa), Wasp, Mallard duck, and Black-billed magpie. Pond Wolf Spiders commonly capture prey such as damselflies and dragonflies, injecting them with fatal poison using its chelicerae, and then proceed to consume them. (Clifford, 1991) In addition, damselfly and dragonfly nymphs will use their powerful jaws to kill and eat mollusks, other insects, crustaceans, worms, and small fish. Another example is Hydatiscus Modestus (Predacious Diving Beetle) that clings to grasses or pieces of wood along the bottom of the pond, hold perfectly still until prey (e.g. tadpoles, glassworms) pass by, then lunge, trapping their soon-to-be-food between their front legs and killing them by biting down with their pincers. (Clifford, 1991). In the forest ecosystem, the sidewalk carabid is a beetle that is prey to may predators like frogs, toads, and birds. As well, daddy long-legs have fangs for predation and prey/feed on insects and fecal material. These interactions parallel those of the grasslands in the sense that insects feed on other insects.

A case of parasitism in the pond is when a wasp stings and paralyzes a Pond Wolf Spider, afterwards taking it to a nest and laying an egg in it. The larvae will consume the still-living spider; often from the inside out. This is a parasitic relationship as the host, the spider, loses by undergoing fatal harm while the parasite, the wasp larvae, gains as it cannot survive without the nutrients and shelter the spider’s body provides. In the forest, deer ticks attach themselves to white-tailed deer. Those ticks get food, and a place to live in, and reproduce, so they benefit from this relationship. Meanwhile, the deer suffer because they’re letting multiple different ticks (especially after reproduction) feed on it’s blood, and some ticks might carry disease, so the deer can get infected. Both of these examples of parasitism are found in the grassland ecosystem.
One example of interspecific competition is between dragonflies and damselflies for prey. Because of pollution in both the water and air, many organisms the two species prey on do not grow as large or live as long, thus being in short supply. This interaction between insects was not highlighted but was for plants and is applicable to the grasslands.

One example of intraspecific competition is between leeches, fighting over food sources. Due to pollution, organisms in the pond such as snails, frogs, dragonfly and damselfly nymphs are easily put at risk. This is an example of intraspecific competition because leeches of the same species feed on these organisms in short supply, consequently resulting in conflict. Some leeches occasionally even eat other leeches as both a defense mechanism and as a way to gain sustenance. Both leeches lose from expending energy and both are usually harmed in the conflict. This is not seen in the grasslands for leeches do not thrive in dry environments but a shortage of food supply is seen as the source of conflict in the grasslands.

An example of Batesian mimicry present at the Nose Hill pond is when harmless hoverflies mimic bees’ and wasps’ distinctive bright striped coloring. As members of Diptera, all hoverflies have a single functional pair of wings, similar to a wasps’. (Clifford, 1991) They are also brightly colored, with spots, stripes, and bands of yellow or brown on their bodies. Due to this coloring, they are often mistaken for wasps or bees. This interaction between butterflies is also seen in the grasslands.

An example of Mullerian mimicry present in the Nose Hill pond would be where flatworms, which excrete toxic body fluids when dying, mimic the poison-carrying nudibranchs. This interaction is not seen in the grasslands, for this is an organism whose niche is the pond, which generalizes the interactions between the different ecosystems of Nosehill. You will notice that those of the forest and grassland are most similar, with exceptions to insects, which reside in multiple ecosystems.

Succession patterns noticed in the grasslands of Nosehill Park by Andrea I
            In the grasslands of Nosehill there are many diverse species of plants, insects and animals around. The large span of land that Noseshill Park covers enables a suitable habitat for numerous animals. Nosehill is currently home to 136 different kinds of birds and 27 species of mammals. Nosehill Park is a climax community because a natural ecological succession was developed through the many ecosystems. Climax community is the stable, final community that develops from ecological succession (Freeman, 2008). Although it is a great living area for many creatures due to exterior impacts the diversity and the large numbers of each animal has decreased. Nosehill was shaped from the glaciers melting and eroding. Plants started to bloom and grow from rocks and gravel; Nosehill became a grassland-dominated park from rocks, this is called primary succession. Primary succession is the gradual colonization of a habitat of bare rock or gravel, usually after an environmental disturbance that removes all soil and previous organisms (Freeman, 2008). There is also a secondary succession; this is another way that can greatly diminish the diversity and numbers or plants and animals. Secondary succession is the gradual colonization of a habitat after an environmental disturbance (e.g., fire, windstorm, logging) that removes some or all-previous organisms but leaves the soil intact (Freeman, 2008). An example of a secondary succession would be how the grasslands and the forests grew back after the fires that had occurred. The scenery grew back to be how it was even if it went through a disaster.
From the first days of Nosehill until now, the surroundings of this park has change immensely. The days where fields of grasslands covered the many blocks of houses lined up side by side; next to each other have replaced the whole prairie. All these houses are located on top of the hill , spanding over the horizon. This is where the first exterior impact on the diversity and specie number comes into place. Many times where there is a large occurrence of rainfall it often collects many garbage, toxins and contaminated goods within the water itself. When this happens the rainwater that has been collected will gradually run down the hill situation across from Nosehill. Soon the toxin water will become a runoff into the boundaries of Nosehill. Due to the heavy rainfall many times the rain water that is running down the Edgemont hill will flood the whole entire park. The water will be gathered at the bottom pits of Nosehill and will stay situated there for a long period of time. If this happens if becomes extremely dangerous as the toxins from the garbage flowing along side with the water will start to contaminate the plants in the nosehill area and will start to kill many organisms due to the high toxicity level found in garbage’s. From the yearly occurrence many living creatures and plant species have decreased rapidly as they take in the contaminated water through root uptake. This poisons them causing the death of a group of organisms or a crowd of plants from the same family. This is why the bottom of nosehill is evidently lower than the rest of the hill. The bottom was made to indent into the ground so that the running waters from the houses built on top of the hill will be able to directly run into the pit without flooding the rest of the surrounding. The construction of this project also leads the plant, organism and animal rate drop as it is disrupting their habitat by creating a deeper hole.
Another reason that contributes to the declination of plant species, insects and animals is the constant disturbance they receive. Nosehill is a national park where many people enjoy hiking and taking their pets to. Before the regulation that banned dogs from entering Nosehill, many were allowed to freely run around Nosehill Park creating disruptions to habitats and leaving manures behind. This affects the stable living conditions that these plants and animals live in. each time we enter and leave their habitat we create destruction to the wildlife, killing plants and bugs on our way leading to a decrease in numbers. As Calgary expands Nosehill Park becomes a tourist attraction that many people enjoy and prefer to visit once in a while. The scenery that Nosehill brings is what attract many people from other cities to come visit. But as the population of Calgary grows the more disruptive we become to the wildlife in Nosehill. We create tracks behind limiting plants from growing normally and naturally on the pathways we walk on.
From then to now, after the time periods were hunting was permitted, extraction the nature was not ceased the numbers and the diversity of these plants, animals and insects have decreased, this is called sere. Sere is the natural succession of a plant or an animal. As time passed by it is natural for plants and animals to most likely decrease in their numbers.
Comparison between the landscape and interactions in Nosehill Park and Edworthy Park
When comparing the landscape of Edworthy park and Nosehill park we have to consider where the two are located. Edworthy park is 314 acres and is 3660 feet above sea level where as Nosehill is only 11.27 square km and 1125 meters altitude. The size of each park plays a large role into what type of ecosystems are found. In Nosehill there are grasslands, ponds, small forests and shrubs. But in Edworthy there is more of a variety due to its size for example ponds, rivers, forests, woods, grasslands and shrubs. The area of the parks allows more or less interactions and ecosystems to develop. The size of the park also limits the types and diversity of the species that live there. As Edworthy park is only 250 feet from the bow river that allows the ecosystems that are near the bow river to intake more water and other nutrients which will allow them to grow stranger and more in numbers. In Nosehill since there is only a small pond plants and animals often have to compete with each other to obtain that water source. That small pond is also not enough to supply for the whole Nosehill.
Some of the major interactions that you might find in both Edworthy and Nosehill Park is predation, mutualism, commensalism and parasitism. Starting with predation is the killing or eating of one organism (the prey) by another (the predator) (Freeman, 2008). An example of this interaction that can be found in both parks is how birds tend to feed on worms and grasshoppers. The predator becomes the preys environment, if the predator is not able to obtain food then they must adapt to their surroundings and change. They can choose to increase their speed, be stealthy or camouflage with its background. Mutualism interaction is a symbiotic relationship between two organisms that benefits both (Freeman, 2008). An example would be when animals eat the fruits off of the plants. The animals benefit from the nutrients that the fruit gives off and the plant will be benefitted in how the seeds can now be dispersed around the park. Commensalism is a symbiotic relationship in which one organism benefits and the other is not harmed (Freeman, 2008). An example would be how deer’s live in shrubs. The deer is gaining by having a shelter but the shrubs are also not looking any nutrients to the deer so it is not harmed. Parasitism is a symbiotic relationship between two organisms that is beneficial to one organism but detrimental to the other. An example would be when small insects like lice attach itself to the mammal. Due to the difference in the ecosystems that both parks offer the interactions among the bugs, animals and plants you might find will also be different
Figure 1: a picture of the labeled bugs caught in Nosehill Park.
We hope that you have found this blog entry informative and entertaining. Personally, we have learned a deluge of facts about the grasslands of Nosehill and view them with more appreciation than we did before. Not only do organisms depend upon each other- nature depends upon them.

Bullick, T. (1997). Calgary parks and pathways. Canada: Blue Couch Books.

Friends of nose hill society. (2011). Retrieved from

Hallworth, B. (1988). Nose Hill A Popular Guide. Calgary: Calgary Field Naturalists' Society.
Kirker, J., & Kary, D. (1996). Exploring nose hill- a hands on field guide. Calgary: Grassroots N.W.: Environmental Awareness Society.

Nose creek and nose hill park. (1997). Retrieved from

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