Course:EOSC311/2020/Geology and Geography of Bogs

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The integration of geologic knowledge, ecological and socio-cultural systems makes bogs a fascinating topic for those who study geology or geography. Bogs are formed from process connected through the hydrosphere, the biosphere, the lithosphere, and the cryosphere. Bogs, like other geologic features, are a result of long periods of slow change. Glaciers are long-lasting bodies of ice that are effective agents of erosion when glaciers move over sediment or bedrock. When glaciers melt they create glacial formations in the topography, types of depressions and lakes allows for water to pool and sets the stage for the water table needed to form a bog. Terrestrialization, the in-filling of shallow lakes, is especially common in regions of former glaciation. Lakes gave way to swamps, swamps gave way to mosses and shrubs, the process of hydric or hydroseral succession. Bogs are marked by acidic soil and water, nitrogen fixation, suppressed nitrification, and a low influx of nutrients, characteristics created from the transformation from lake to swamp. Bogs have been used for millennia for storm drainage, reduced flooding risks, fur from fur-bearing animals, sustain irrigated agriculture from higher water table, support herding and grazing, timber, fossil fuels, and gemstones. Climate change is felt more through bogs as so few buffers from the effects of drought and fire on bog ecosystems.

Statement of Connection

Geography (Environment and Sustainability) studies the interactions of physical, ecological, economic, socio-cultural, and political systems. These systems are integral to learning about the world we live in as well as shapes the future of life as we know it. This program at UBC combines the fields of Human Geography and Geographical Bio-geo-sciences in order to integrate the learnings found in both of those programs. This interdisciplinary study allows students to see the world with multiple moving parts that influence one another.

Geology is a study similar to Geography. Geologists study the Earth, it’s processes, history, changes, interior, exterior, and the materials that make up the Earth. In order to study all of these, geology takes an interdisciplinary approach using all of the other sciences to inform itself. One of the most important similarities is the dedication to ensuring the safety of Earth and its inhabitants that both disciplines holds to high esteem. One of the most important differences is the aspect of time. Geology has its own timeframe as the processes of the Earth move at incredibly slow rates.[1]

Bogs are a prime example of how the studies of geography and geology can be integrated. Bogs, like other natural features, are created by long term geologic processes- glaciation and lake formation. Bogs provide environments for unique plant and animal habitats, as well as many resources to be extracted by humans. These resources like coal, gemstones, and fossils are governed by geologic principles. Studying bogs requires knowledge of all sciences to get a fulsome picture of The way we take care of our bogs going forward will determine further feedback loops for climate change. This combination of geologic knowledge combined with ecological and socio-cultural systems makes bogs a fascinating topic in both areas of geology and geography.

How Bogs are Formed

A mire is a peat-producing ecosystem, an umbrella term for types of wetlands such as bogs and fens. A bog is an ecosystem of acidic, wetlands with unique plant communities and only receive water through precipitation. A fen is the second type of mire where the wetland receives its water by both rainfall and ground water flow.[2]

The six primary forces in the development of bogs is climate, geomorphology, geology, soils, bio-geography, and human activities.[3]

Geologic Time

In order to understand how bogs form, it is useful to understand how long processes like these take in geologic time scales. Bogs, like other geologic features, are a result of change over long periods of time. Earth’s geological processes are very slow so geologic processes have a different span of time than other scientific processes. Geological time must be very long to account for large changes happening on Earth that can take millions of years to develop. Understanding geological time allows us to fully understand how geological processes can produce the features that they do despite sometimes moving at less than a millimeter per year.[4] Even though we can not see mountains rise, glaciers melt, and canyons eroded away, through the understanding of geologic time they become tangible systems of change.

Bogs are formed from the interactions between the hydrosphere, the biosphere, the lithosphere, and the cryosphere. We are able to understand how bogs have transformed over time via proxy data, or data that can be derived from natural materials with characteristics that are affected by climate in a certain way. Proxy data is often materials that have been preserved over thousands of years. Within bogs, often times the proxy data that is used is peat cores or sediment sampling. Similar to ice cores, peat cores have captured a sample of Earth’s atmosphere including gases and particles, as well as different types of plants that have grown in the bog over time.[5] Within these peat samples, environmental and climatic data can be gathered from microfossils and macro fossils contained in the plant remains.[3] The principle of superposition is the idea that young sedimentary rocks develop on top of older rocks. So as you move down a stratigraphic column you ‘go back in time’.[4] As you examine a peat sample, the deeper the sediment was in the ground the older it is. This idea allows us to see the linear progression of time through sediments, plants, and fossils that exist within the core.

Bogs begin with glaciers that formed over 15,000 years ago.

Glaciers

Glaciers are long-lasting bodies of ice that are several metres thick and hundreds of metres across. The oldest known glacial period is the Huronian Glaciation which lasted from 2.4 to 2.1 Ga. The most intense period of glaciation on Earth was the Cryogenian Period, also known as “Snowball Earth”. During this time, it is believed that glaciers covered the whole planet even the equatorial regions. The most recent glaciation period, and the period that began the process for most bogs, were the Cenozoic Glaciations. In Canada, the creation of bogs came from the melting of much of the massive Laurentide and Cordilleran Ice Sheets.[6]

They move under their massive weight influenced by gravity which pulls them down slopes of the mountains they form on. Under the high pressure conditions of the massive amounts of ice, the ice within glaciers moves plastically over irregularities in rocks. When glaciers move over sediment or bedrock, they become effective agents of erosion. The rocks embedded within the ice abrades against the surfaces under the tremendous pressure of the weight of the glacier. This process allows glaciers to change the topography of the Earth as it moves, even as it moves very slowly. Glacial deposits create distinct erosion features in the land. The most significant features in the creation of bogs are Cols, Cirques, Tarns, Rock Basin Lakes, Finger Lakes, Moraine Lake, and Kettle Lake. These types of depressions and lakes allows for water to pool and sets the stage for the water table needed to form a bog. Glaciers erode land into flat plains, allowing for the topography needed for bogs.

This image describes some of the topographic landscape features created by glaciers. [6]

Sediments transported and deposited by glaciations are important for groundwater reservoirs. Sediments that are moved and deposited by glaciers is known as till.[6] Glacial till consists of clay, silt, sand, and stones that ranges from boulder to pebble sized deposits. This kind of material makes for excellent foundation material based on its high bearing capacity. Glacial sediments create aquifers that can be filled easily by downward infiltration from precipitation.[7] These create aquifers that bogs utilize after glaciers recede.

Glaciers receding and Creation of Glacial Lakes

12,500 years ago, the glaciers that once filled Canada retreated due to changes in the climate of the time.

As glaciers recede, the glacial till provides sediment for which lakes and the subsequent bogs to thrive on. These deposits and their porosity allow for a small aquifer to form that impedes drainage forcing water to collect.[8] When the glacier melts, the till is exposed to be a sheet of well-compacted sediment up to many metres in thickness.[6]

When large ice masses like glaciers are reduced or removed, they leave behind depressions caused by the weight of the ice sheet. Within these depressions, lakes are left behind. 14,000 to 10,000 years ago was the close of the last glaciation where these glacial lakes were created.[3] Lakes form in hollows and depressions that were caused by glacial retreat. [8] Some glacial lakes were short lived and only lasted until they overflowed or were eroded, others survived long enough to create long lasting fresh water lakes.[3]

Lake filled in

Terrestrialization is the in-filling of shallow lakes. Terrestrialization is especially common in regions of former glaciation, such as Scandinavia, northern Russia, northern United States, and much of Canada.[3] This process begins when plants that grow on the edges of the lake grow or decompose into the lake. When these plants start to colonize into the lake, this creates a shallow mat which other plants can start to grow on top of.[9] Plants cover the lake and the water beneath is used to keep the vegetation hydrated and adds to the aquifer below.

Eventually, the water below these mats of plant and soil causes the water to drain away. The area is then left with the lake sediment, decomposing organic material, and the plants that took the lake's place. The combination of vegetation encroaching on the lake's edges, sedimentation of the lake, and creation of plant mats causes lakes to give way to marshy swamps.[8]

Swamp

Lake gave way to lichens, lichens gave way to mosses and shrubs. This is called hydric or hydroseral succession.[8] Hydroseral succession takes several millennia to progress through all of the stages.[3] Paludification is the creation of swamps from poorly drained forests which causes layers begin to develop under the surface.[9] This process happens when groundwater is closer to the surface than in other areas of the woodland and anaerobic soil conditions are created.[3] Shrubs and trees dominated the swamps before when the surface was dry, but the soil and sediment saturated in water most of the year caused the shrubs and trees to give way to marshland.[8]

A swamp differs from a bog as a swamp is a forested wetland whereas bogs do not contain trees or tall shrubs.[2] The differences in rates of bog formation are determined by the size of the area, as well as thickness and age of the peat. Changes in surface drainage also causes ground-water increases and differences in bog formation. Once paludification is established and wetland conditions are created this eventually leads to peat accumulation.[3] Dead, un-decomposed, and slowly decomposing organic matter depletes oxygen supplies and creates anaerobic soil with a high water table. This process gave way for sphagnum to take over the previous swamp.[8]

This diagram represents the growth of a bog starting with the first appearance of Sphagnum moss until it is a fully expanded bog. The diagram is divided into Sphagnum peat, sedge peat, lake sediment, and bog pools to represent the four different layers within bogs. [3]

Growth of Sphagnum Moss

Sphagnum plants are the mosses that make up most of a bog and most peat.[8] Sphagnum is a type of moss that differs from other species of moss because its leaves contain both living cells and inflated dead cells. The dead cells near the bottom of the plant are used to absorb water up to 20 times it's dry weight. The living cells towards the top of the plant are used for photosynthesis.[2] The upper most layer of the bog, often called the acrotelm, is vital to the hydrology of the bog because of its ability to form peat. This layer is the part of the bog that regulates and stores water.[9] The lower layer of a bog is the catotelm. This section is created as the sphagnum mosses grow and their weight increases, the material below this weight becomes compacted.[10]

Peat is partly decomposed sphagnum and other plant debris and is created when plants produce more biomass than can be decomposed under low oxygen and waterlogged conditions. The increased growth of sphagnum that can not be decomposed turns the wetland very acidic and creates favorable conditions for bog species alone.[9] Sphagnum peat is able to grow in this environment because of its shallow roots and warm surface layer it creates from insulating heat. The incredibly porous leaves and dead cells near the bottom of the plant allows these plants to absorb and hold large quantities of water.[8]

Bog

Bogs are marked by acidic soil and water, nitrogen fixation, suppressed nitrification, and a low influx of nutrients.[8] Bogs are carbon sinks due to waters depleted in oxygen prevent plant material from decaying and releasing their carbon back into the carbon cycle as carbon dioxide.[5]There are three types of true bogs - raised bogs, blanket bogs, or tropical bog forests. There are also valley bogs and string bogs, but these are fens rather than bogs.[2] Blanket bogs are rain fed bogs with vegetation growing directly on rock or soil. Raised bogs are rain fed but grow above another type of wetland such as infilled lake, flood plain, or blanket bog. Raised bogs are the most common type of bog, developing in infilled lake basins, wide flood plains, or coastal flats. Valley bogs receive their influx of water from downslope nutrient-poor catchments as well as rain. These tend to be smaller than raised and blanket bogs. Bogs can start on any type of soil or rock. However, it is rare for bogs to be formed above limestone as limestone is dissolved by water and the lime-rich water will be absorbed by the peat. Yet, if the bog sits far enough above the limestone the water is kept far enough away from the limestone.[10]

To promote the preservation of bogs and their unique species, the United States Postal Service created a block of postage stamps that depicts the carnivorous plants that are characteristic of bogs. These plants are trapping native insects, spiders, and other small animals to supplement their nutrient intake. [3]

These wetlands are home to many types of unique plants and animals that find refuge in the waterlogged ground. Bogs are critical in providing habitat to Sandhill Cranes and other estuary waterfowl.[9] Bogs are composed of sphagnum, grasses, pine, and birch that are able to survive with the help of mycorrhiza, a fungi that absorbs minerals.[10] One characteristic of bogs are insectivorous plants that compensate for the low nutrient levels of the soil by trapping and digesting insects.[2]

Due to bogs being such stable ecosystems with little requirements to continue, it is believed that bogs can persist with little change for thousands of years.[8]

Impacts of Climate Change

Climate change is being felt more throughout the world's bogs as so few areas of wild vegetation remain to form a reservoir to help buffer the effects. Drying peat - dried by climate change and other impacts - allows for trees to colonize the land. When there is a loss of peat in large-scale amounts from being dried or drained, the remaining peat shrinks and wastes from lack of ground water.[10] Factors that reduce precipitation, alter nutrient accumulation, changes in temperature, and negatively influence hydrophytic plants and animals could cause the shrinkage of bogs worldwide and release the greenhouse gases that are sunk in these wetlands. Generally, a warmer and drier climate would shrink bogs while a cooler, wetter climate would cause bogs to grow.[3] Feedbacks are a series of interactions that are able to amplify a change that is taking place.[5] This creates a simple feedback where a cooler, wetter climate leads to expanding bogs, burial of organic carbon, as well as drawing in atmospheric greenhouse gases. This would in turn result in a still cooler climate and further growth of bogs. The current shift toward warmer, drier climate is having the opposite consequence, which is a positive feedback as well. Drought conditions due to less precipitation in some areas has promoted fires in bog ecosystems. The bogs in Alaska and Canada are experiencing more frequent fires due to low water tables. These fires are releasing the stored carbon and greenhouse gases back into the atmosphere. Bogs and other wetlands are heavily impacted by climate change as they are important sources of carbon dioxide and methane.[3]

Bogs in British Columbia

Google Map showing the locations of Camosun Bog, Burns Bog, Rithet's Bog, Cinema Bog, Yellowpoint Bog (Ladysmith), and Burnt Cabin Bog.

Camosun Bog

This site was a post-glacial lake before it was a bog. At it's historical maximum around 12,000 years ago, the lake would have been 1,500 m by 300 m, and was 6-8 m deep. Ecological succession caused the terrestrialization of the lake by deposition of organic material on the edges and lake bed 7,000 years ago. This was followed by a swamp, and in turn, was replaced by Camosun bog. Camosun Bog sits in the University of British Columbia's "University Endowment Lands" or Pacific Spirit Park, an area that was once the site of BC's prolific logging industry. There is long time human engagement with this bog, first with the Musqueam First Nation, and then with colonial loggers.[11] Restoration efforts by a group called the "crazy boggers" have put in over 15,000 hours to recover this bog to its state prior to the urban drainage schemes, clearing fires, and land fill that plagued this bog for many years.[8]

Burns Bog

This raised bog covers 3,000 hectares of Fraser River delta. Burns Bog exhibits typical characteristics of a raised bog ecosystem with a peat mound above the regional water table, internal water mound, acidic nutrient-poor water, two-layered peat deposit, and peatland communities of sphagnum moss. This bog exhibits at least 12 distinct species of Sphagnum moss. Burns Bog is an urban bog, meaning it is largely isolated from other natural areas by agriculture, residential areas, and industrial development. Burns bog has been disturbed by peat harvesting, drainage ditches, landfill, and clearing. Due to peat mining, only 29% of this bog's original dynamic water storage is intact, the water in the bog has been affected by rapid discharge ditches built which has lowered the water table 25cm from the 1930s. This has caused an advance in forested vegetation into the bog as well as making the bog at risk to drought.[9]

Rithet's Bog

This bog is located on the Nanaimo Lowlands within the city limits of Victoria. Rithet's is a disturbed bog in the Pacific Temperate wetland region, meaning it has been largely changed by human activity. As a bog affected by human disturbance, Rithet's experiences lower plant species richness and lower pH than the other bogs on Vancouver Island. In this region, Rithet's is exposed to droughts in the summer due to the little precipitation the Island receives in the summer and high evapotranspiration rates from the increased summer heats. This makes this bog especially sensitive to anthropogenic disturbances in the water table during this time and takes a long time to recover the aquifer in the winter. These droughts and other anthropological disturbances could cause a shift from bog ecology to a forest ecosystem as productivity shifts.[12]

Cinema Bog Ecological Reserve

Cinema bog is so far north in British Columbia that it is has a diverse bog habitat which contains many plant species at or near their southern limit of distribution. Cinema Bog is along a north-south trough, likely created by a glacial meltwater channel. The bog is located on the Fraser Basin, 28 miles north of Quesnel and Cinema. This treeless bog land is surrounded by bog forest that is host to logging and other natural resource extraction that is still active today. There has been local peat extraction that has resulted in drainage of this raised bog.[13] Cinema Bog has three distinct vegetation types: central raised bog, forested bog, and fens. This is home to cottongrass, sphagnum, Labrador tea, bog cranberry, cloudberry, and sundews.[14]

Yellowpoint Bog Ecological Reserve (Ladysmith)

Ladysmith bog is located on the northern Nanaimo Lowland of Vancouver Island. This coastal bog acquires some nutrients from atmospheric sea spray. Even though it is on Vancouver Island, like Rithet's bog, it does not experience the same level of drought due to fog restricting the amount of evapotranspiration that occurs in the summer. [12] Ladysmith Bog is a representative bog of this area and has been protected for this purpose. This bog is a sensitive ecosystem associated with rare plant species as well as biodiversity values. Sensitive species, such as waterfowl, and aquatic mammals of beavers and otters, are protected in Ladysmith Bog.[15] The maintenance of the local beaver population is believed to help protect the area from drying out.[16] There are increased intensive urban and agricultural pressures on the bog and its forest sub zones. This reserve is on the historical lands of the Chemainus First Nations, as well as the historical site of an early Chinese community. The thin soils over bedrock is sensitive to erosion and thus has been protected from mountain biking, off road vehicles, horse-riding, and cranberry harvesting.[15] The bog was created by glacially scoured rocks of the cretaceous Nanaimo Formation and the bog occupy the depressions created by the glacial movement.[16]

Burnt Cabin Bog Ecological Reserve

This large wetland lies within the traditional territories of the Wet’suwet’en and Ned’u’ten. Aboriginal Rights are to be honored and protected on these lands. Burnt Cabin is considered a provincially unique ecosystem as a low moor bog and is associated with several rare plant species. Many of these rare species were established as glaciation and are recognized as relics. Adjacent land to the bog is used for forest development, woodlots, private lots, and livestock grazing areas.[17]

How Humans have Utilized Bogs

Bogs have been used for millennia for storm drainage, reduced flooding risks, fur from fur-bearing animals, sustain irrigated agriculture from higher water table, support herding and grazing, timber, fossil fuels, and gemstones.[3]

Surface Resources

Bogs provided plants that were used and continue to be used by Indigenous communities for thousands of years, as well as settler communities as well. Bog plants provide excellent sources of food like blackberries, blueberries, cranberries, Labrador tea, salal, sphagnum.[9] Waterfowl, such as ducks, waders, as well as many land birds, have been a staple meat from bogs.[10] Bog laurel can be utilized to heal skin ailments. Labrador tea can be brewed to soothe sore throats. Sphagnum has been used for bedding, feminine hygiene products, and diapers due to how absorbant this plant is.[9]

Peat can be used for substrates for horticulture for the same reason.[10] Peat has been used for fuel as it is easy to obtain and is a compact form of carbon. Peat has been cut in enormous quantities in some areas. Blocks of peat could be cut by hand or by mechanical cutting. Not only cut into blocks, peat has been cut into round strips called sausages. This kind of peat extraction requires a large bog area as much of the bog biomass is pulled up.[3] Well into the 20th century, peat was still being cut for use as fuel in power stations, especially in Ireland. Present technology allows peat to be removed much faster. After removing peat, the areas that were cut would usually be re-colonized by reed swamp or new peat.[10]

The Tsawwassen First Nation has utilized the networks of water ways connected to bogs in order to gain access to surrounding areas. Bogs were also utilized as canoe portage areas.[9]

Modified wetlands have been used widely for cropland and agricultural zones. Evaporation ponds built into bogs have been used to create salt production sites. This allows for the water to be evaporated and only brine and salt to remain.[3]

Underground Resources

Bogs have existed on Earth as long as the fossil record goes back. As bogs accumulate large amounts of organic deposits, those deposits can be transformed into coal over long periods of time. Ancient bogs and wetlands have produced one third of the today's global coal supply. In the late Paleozoic, there was a massive accumulation of coal after large accumulations of terrestrial vegetation such as mosses and lichens. Permo-Carboniferous coal is found on every modern continent without a distinctive pattern to its distribution. When reconfiguring the continents into the shape the supercontinent Pangea took, it can be seen that coal deposits were created in equatorial and temperate zones. Coal from equatorial zones were formed in the largest swamp environments ever to exist in Earth’s history. Temperate coal was created in the very first non-tropical peatlands at latitudes so high they were able to form under permafrost. Cretaceous coal comes from the expansion of peatlands during the Cretaceous Period. Fossils of dinosaurs, aquatic birds, and flying reptiles are commonly found in coal from this period. During the mass extinction of this time, it is believed that these wetlands served as refuge for the plants and animals that survived.[3]

Conclusion / Your Evaluation of the Connections

Geographers study the interactions of physical, ecological, economic, socio-cultural, and political systems. Geologists study the Earth, it’s processes, history, changes, interior, exterior, and the materials that make up the Earth through an interdisciplinary lens. The integration of geologic knowledge into ecology and socio-cultural systems allows for a greater understanding of the multiple moving parts that influence the Earth, it’s processes, and its inhabitants. Climate change is changing the way in which the world functions and this is does not exclude bogs. Bogs provide environments for unique plant and animal habitats, as well as many resources to be extracted by humans. If we extract resources without caution or further climate change as we have, bogs will not have the buffers of high water tables and peat to protect them from drought, fire, and other factors. In order to protect bogs and other sensitive ecosystems, we require knowledge of all sciences to get a fulsome picture of The way we take care of our bogs going forward will determine further feedback loops for climate change. Bogs, how they’ve come to be and how their future may be impacted, are a prime example of how the studies of geography and geology can be integrated.

References

  1. ↑ Panchuk, Karla (2019). "Chapter 1. Introduction to Geology". Physical Geology. University of Saskatchewan: Crreative Commons Attribution - Non Commercial - ShareAlike 4.0.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 Allaby, Michael (2013). A Dictionary of Plant Sciences. Oxford, UK: Oxford University Press. ISBN 9780199600571.
  3. ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 Sandusky Aber, James; Pavri, Firooza; Ward Aber, Susan (2012). Wetland environments: A global perspective. West Sussex, UK: Wiley-Blackwell. ISBN 978-1-4051-9841-7.
  4. ↑ 4.0 4.1 Panchuk, Karla (2019). "Chapter 19. Measuring Geological Time". Physical Geology. University of Saskatchewan: Creative Commons Attribution.
  5. ↑ 5.0 5.1 5.2 Panchuk, Karla (2019). "Chapter 16. Earth-System Change". Physical Geology. University of Saskatchewan: Creative Commons Attribution.
  6. ↑ 6.0 6.1 6.2 6.3 Panchuk, Karla (2019). "Chapter 17. Glaciation". Physical Geology. University of Saskatchewan: Creative Commons Attribution.
  7. ↑ Turner, Robert; Clague, John; Groulx, Bertrand; Journeay, J. Murray (1997). "Geological Map of the Vancouver Metropolitan Area". CGEN Archive.
  8. ↑ 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 Hermansen, Sally; Wynn, Graeme (Fall 2005). "Reflections on the Nature of an Urban Bog". Urban History Review. 34: 9–27 – via JSTOR.
  9. ↑ 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 Hebda, R.J., K. Gustavson, K. Golinski and A.M. Calder, 2000. Burns Bog Ecosystem Review Synthesis Report for Burns Bog, Fraser River Delta, South-western British Columbia, Canada. Environmental Assessment Office, Victoria, BC.
  10. ↑ 10.0 10.1 10.2 10.3 10.4 10.5 10.6 Haslam, S.M. (2004). Understanding Wetlands: Fen, Bog, and Marsh. London: CRC Press. pp. 1–316. ISBN 9780429212130.
  11. ↑ Szabo-Jones, Lisa; Brownstein, David (2015). "Chapter 4. A Natural History and Dioramic Performance: Restoring Camosun Bog in Vancouver, British Columbia". Sustaining the West: cultural responses to Canadian environments. Wilfrid Laurier University Press. pp. 43–64. ISBN 1-55458-923-1.
  12. ↑ 12.0 12.1 Golinski, Georgina Karen (2005). "Mires of vancouver island, british columbia: Vegetation classification and differences between disturbed and undisturbed mires". Dissertations & Theses Global: 1–112 – via ProQuest.
  13. ↑ Metcalfe, John; Wilkin, Nancy (March 2003). "Cinema Bog Ecological Reserve Purpose Statement" (PDF). Environmental Stewardship Division.
  14. ↑ Beaudry, Pierre; Beaudry, Leisbet; Martin, Marnie; Floyd, Bill (February 28, 2002). "Hydrology and Monitoring of Cinema Bog" (PDF). BC Parks.
  15. ↑ 15.0 15.1 Heath, Dick; Wilkin, Nancy (August 2003). "Ladysmith Bog Ecological Reserve Purpose Statement" (PDF). Environmental Stewardship Division.
  16. ↑ 16.0 16.1 "Yellow Point Detailed Ecological Reserve Description" (PDF). BC Parks. September 14, 2010.
  17. ↑ Markides, Hugh; O'Gorman, Denis (September 2000). "Management Direction Statement for Burnt Cabin Bog Ecological Reserve" (PDF). Ministry of Environment Lands and Parks.
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