Description of University Endowment Lands Study Sites
In order to determine the anthropogenic effects on the soil quality and to what degree metapedogenesis is occurring on the University Endowment Lands (UEL), several study sites have been identified. The initial study was carried out by Lavkulich and Rowles (1971) in 1970, and it focused on the impacts of four land-use practices on soil development on a second growth forest, alder (Alnus rubra Bong.) forest, pasture, and an annually cultivated field in the UEL. Pasture has been eliminated, while three other land uses from the initial study are still present on UEL.
The whole area presently occupied by the UEL was originally under Douglas-fir, western hemlock, and western redcedar forest until the late 1800s when it was logged. UEL is located within the Coastal Western-hemlock (CWH) biogeoclimatic zone (and CWHdm subzone). This region is characterized by cool, dry summers, and mild, wet winters. Of all 14 biogeoclimatic zones in BC, the CWH is the rainiest.
Some characteristics common to CWHdm and the UEL are a predominance of Douglas-fir and western red cedar. Additionally, understory plants that are common for this subzone are salal (Gaultheria Shallon Pursh) and bracken fern (Pteridium aquilinum (L.) Kuhn). Those two species are the dominant herbaceous species evident in the UEL forests.
The UEL are characterized by layering of many different sediments. The deepest of these deposited sediments is the bedrock, which formed from 70 to 40 million years ago. The bedrock is often many metres thick and consists of sandstone, mudstone, and sedimentary conglomerates. Approximately 65 million years ago, Vancouver was a much warmer region than it is presently. The area was a lowland tropical forest where upland rivers deposited their sediment load.
Around 10 million years ago the area slowly began cooling as the last Ice Age began. This Ice Age, known as the Pleistocene Epoch, lasted from 2 million years ago to 10,000 years ago. During the Pleistocene Epoch, much of BC was covered by the Cordillean Ice Sheet. The later part of the Ice Age was known as Fraser Glaciation occurring from 30,000 to 12,000 years ago. It began with increased snowfall levels and the formation of permanent snowbanks and glaciers. The Fraser Glaciation was a cycle during which there were repeated advances and retreats of glaciers, which deposited some materials from the mountains to the lower lands. During the most extensive glaciation, the area of today’s Vancouver was covered by glaciers that were estimated to be around a kilometre thick. The glacier depressed the land so that it rested in many places below sea level. The effects of the glaciers is still evidenced by the fact that many of the soils at UEL have compacted subsoils as a result of the glacial pressure exerted during the last Ice Age.
Beginning around 13,000 – 12,000 years ago, the glaciers began retreating. The retreating glaciers deposited till (i.e., unsorted mixture of gravel, sand, silt, and clay), which compacted under the weight of the glacier. The retreat of the glaciers also meant that the depressed land was relieved of glacier’s weight and began to rebound and rise above sea level. As the land rebounded, not all of the land rose out of the water at once; rebounding land gained around 1 metre every 10 years. For example, upland areas of Vancouver such as Point Grey, which lie at or below 200 m above sea level, were below sea level for a time and later became beaches.
The upland areas were characterized by the deposit of glacial-marine sediments, but these sediments were wave washed and many of the finer fragments were lost in either seawater or meltwater, leaving behind parent material dominated by sand and silt size particles. The deposition of Sunnyside sand and Bose gravel deposits occurred on top of the aforementioned compacted till at as the glaciers retreated. Melting glaciers also left erratics from the Coast Mountains, which are granitic rocks ranging from several centimetres to several metres in diameter.
The effects of glaciation can be observed in the three landscape types, which distinguish the southwestern coast of BC: lowlands, uplands, and mountains. Vancouver and the UEL lie on the uplands comprised of the Ice Age sediments left by retreating glaciers. The lowlands (that include Richmond, Delta, and Chilliwack) are the post-ice age sediments, built up over time by the ocean and Fraser River. The mountains, located north and east of Vancouver, are part of the Coast and Cascade Range, and they consist of original bedrock which was not eradicated by glaciation.
Some background resources to better characterize the study sites:
UEL Geology Maps
Use the following UEL maps to further investigate the soil and underlying geology of the sites.