Thousand Islands – Frontenac Arch
TheThousand Islands – Frontenac Archregion or theFrontenac Axisis an exposed strip ofPrecambrianrock inCanadaand theUnited Statesthat links theCanadian ShieldfromAlgonquin Parkwith theAdirondack Mountain regioninNew York,an extension of theLaurentian mountainsofQuébec.TheAlgonquin to Adirondacksregion, which includes the Frontenac Axis or Arch, is a critical linkage for biodiversity and resilience, and one with important conservation potential.[1]The axis separates theSt. Lawrence Lowlandsand theGreat Lakes Lowlands.It has many distinctive plant and animal species.[1]It is one of fourecoregionsof theMixedwood Plains.
TheThousand Islandsin theSaint Lawrence Riverhave a distinctive flora and fauna and are a part of the biological corridor.
Geology
[edit]Thebedrockis mostlygneiss,granite,andmarble,more than a billion years old.[2]The Frontenacterrainis the youngest of the Ontario portions of the arch, dated at 1.2 billion years old.[3]These rocks were once part of a large mountain chain of the ancientsupercontinentofRodinia.There is also ameteor crater near Holleford,where theshieldmeets thelimestoneplains of southeastern Ontario.[4]
Ecology
[edit]The area is distinctive for having tree species typically found further south, and reaching their northern limits.[5]One example is pitch pine (Pinus rigida). Shallow soils and recurring fire have also produced unusual fire barren communities.[6]These provide habitat for rare plants, such as bear oak (Quercus ilicifolia) and deerberry (Vaccinium stamineum), as well as rare animals, such as the five-lined skink (Plestiodon fasciatus) and gray rat snake (Pantherophis spiloides).[7]There is high bird diversity, including thecerulean warbler,considered nationally endangered owing to the destruction of forests. Although the most important factor producing the fauna and flora is likely the bed rock, the moderating effect of theGreat Lakesmay also be factor. Also, some northern species extend their range south, drawn by the ruggedgranitelandscapes of the Canadian Shield.
The basic ecosystem type of the area istemperate deciduous forest.The area has a long history of logging, which has depleted these forests of larger trees. Settlement tends to have occurred in the areas of deeper soil, and fire has particularly influenced the uplands. Reference to the forest descriptions of early surveyors has documented decline in species such as hemlock, which were preferentially removed for leather tanning.[8]Criteria for restoring these forests have been established, and include increased tree size, spring ephemeral abundance, and coarse woody debris.[9]Pollen cores from Lanark County provide information about longer term trends in forest cover.[10]
There is a wide array of wetlands, ranging from larger marshes along the St. Lawrence river, to smaller marshes and bogs along water courses, and large numbers of beaver ponds. The cycles in vegetation in beaver ponds contribute to further wetland diversity; depending upon the amount of beaver activity, there may be open water, marsh, wet meadows or shrub thickets.[11]Some lakes in the area, such as Bob's Lake, also support uncommon species of turtles, such as themap turtlesandBlanding's turtles.Where there ismarblebedrock, or other sources of calcium,fensmay arise. These often have unusual calcium dependent wetland plants.[12]
A southern portion of this region was designated aBiosphere ReservebyUNESCOin 2002, theFrontenac Arch Biosphere Reserve.[13]Within this biosphere reserve is the relatively smallSt. Lawrence Islands National Park.[14]Although it is small, it has many Frontenac Arch species mentioned above, including deerberry, Blanding's turtle, and five-lined skinks.[15]Further north, there is still a large gap in the ecological link toAlgonquin Park.In this gap are smaller parks such asFrontenac Provincial ParkandBon Echo Provincial Park.
References
[edit]- ^abKeddy, Cathy (November 1995)."The conservation potential of the Frontenac Axis: Linking Algonquin Park to Adirondacks"(PDF).The Canadian Parks and Wilderness Society - Ottawa Valley Chapter:72.Retrieved2023-10-16.
- ^Eyles, Nick. Ontario Rocks. 2002. Three Billion Years of Environmental Change. Fitzhenry and Whiteside, Markham, Ontario. Chapter 9.
- ^Eyles, Nick. Ontario Rocks. 2002. Three Billion Years of Environmental Change. Fitzhenry and Whiteside, Markham, Ontario. Figure 9.2A
- ^Keddy, P.A. 2008. Earth, Water, Fire. An Ecological Profile of Lanark County. General Store Publishing House, Refrew, Ontario. p. 61-63.
- ^Beschel, R.E., P.J. Webber and R. Trippet. 1962. Woodland transects of the Frontenac Axis region, Ontario. Ecology 43:386-396.
- ^Catling, Paul M and Vivian R. Brownell. 1999. The flora and ecology of southern Ontario granite barrens. Pages 392-405 in Anderson, R.C., J.S. Fralish, and J.M. Baskin (eds). Savannas, Barrens, and Rock Outcrop Plant Communities of North America. Cambridge University Press, Cambridge.
- ^Keddy, Cathy J. 1995. The Conservation Potential of the Frontenac Axis: Linking Algonquin Park to the Adirondacks. Canadian Parks and Wilderness Society, Ottawa, Ontario. 59p.
- ^Keddy, Cathy J. 1993. Forest History of Eastern Ontario. A report prepared for the Eastern Ontario Forest Group, Kemptville, Ontario.
- ^Keddy, P.A. and C.G. Drummond. 1996. Ecological properties for the evaluation, management, and restoration of temperate deciduous forest ecosystems. Ecological Applications 6: 748-762.
- ^Keddy, P.A. 2008. Earth, Water, Fire: An Ecological Profile of Lanark County. General Store Publishing House, Renfrew, Ontario.p. 51-52.
- ^Keddy, P.A. 2008. Earth, Water, Fire: An Ecological Profile of Lanark County. General Store Publishing House, Renfrew, Ontario. Fig. 2
- ^Plants of Lanark County, Ontario--2013 Edition David J. White
- ^Frontenac Arch Biosphere Reserve
- ^Thousand Islands National Park
- ^Species at Risk in the 1000 Islands Ecosystem
