|
5.1 Description of Natural Heritage Values
Purpose of this section: To describe the Natural Heritage features of the rivers and their immediate environments.
The Three Rivers watershed has been extensively altered by human activities, typical of the Prince Edward Island landscape as a whole. For a river to be judged to have outstanding natural heritage value, it must meet at least one of four CHRS natural heritage value selection guidelines and possess all of the integrity values. Three Rivers does not meet any of the four guidelines and thus is not being nominated based upon its natural heritage values. However, Three Rivers' most significant natural heritage values are briefly highlighted here.
As with the rest of Prince Edward Island, the bedrock of Three Rivers is mainly sandstone as can be seen at the many sites of coastal exposure in the estuaries. This sandstone dates from the Permo-Carboniferous to Triassic (300 to 200 million years ago). As this is highly erodible material, few fossils or other representations of major periods of geological time are found along the river corridors.
Glaciation of the Three Rivers area is evident in both its surficial deposits and drowned forests. Between Panmure Island and Boughton Island, there are seven sites where drowned forests have been identified. This is a significant proportion of the 30 sites known to occur off Prince Edward Island's coast, and represents the greatest concentration of drowned forests around PEI. These forests are proof of lower water levels during the last glaciation, in which ice began to retreat some 13,000 years ago. There are comparatively few glacial erratics in the Three Rivers area, and indeed throughout most of Kings County. Only six locations of these glacial remnants have been found in the area.
The upland areas of Three Rivers are primarily sand or clay-sand phase till and the riparian zones consist of mostly meltwater pond deposits. Areas of ablation moraine occur on the Georgetown peninsula, St. Andrew's Point, and along much of the Valleyfield River. There is a small kame field in the Victoria Cross area, within the meltwater pond deposits of the Montague River. Two small eskers are also found within the meltwater pond deposits of the Brudenell River near New Perth, and two larger ones occur in this zone along the Cardigan River east of Lorne Valley. Minor peat bogs are scattered throughout the area, and there are a few sand beaches or bars (Panmure Island, Georgetown Harbour, north site of Georgetown peninsula, Red Point, Launching, Boughton Island).
A mixture of woodland types extending to the rivers' shores makes for attractive combinations of human influenced landscapes and forest cover. Wildlife and wildlife viewing are strong features for the entire area, with an important Great Blue Heron colony at Boughton Island. Migrating waterfowl use the entire estuary and salmonids are common throughout the watershed. There are at least nine provincially rare vascular plant species known from Three Rivers, and one of these, Rough Avens (Geum laciniatum), is also rare in Quebec. The internationally-endangered Piping Plover has nested on Launching Point as recently as 1984 and as local populations of this bird increase, Three Rivers may regain its role as plover habitat in the future.
The presence of an offshore island in Cardigan Bay, with a variety of habitats and shoreline types is one of the most important natural features of the area. The estuary and tidal area of the Brudenell River area in particular has a beautiful blend of gently sloping shorelines with mixed woods, banks, sandy beaches, small salt marshes and agricultural fields. The Montague/Valleyfield River drains the Caledonia Hills, among the highest elevations in the province. A drowned forest occurs in each of the estuaries, evidence of significant ongoing processes in the evolution and form of the river.
Three Rivers clearly meets part of the natural values guidelines as there are areas of exceptional natural beauty on each system.
5.2 Assessment of Natural Heritage Values
Purpose of this section: To identify which of the natural heritage selection guidelines appear to be met by the river, by quoting each guideline and briefly describing the natural heritage values that appear to meet them.
Outstanding Canadian natural heritage value will be recognized when a river environment meets one or more of the Natural Heritage Values Guidelines for Canadian Heritage Rivers. Three Rivers does not appear to meet any four natural heritage value guidelines, and thus is not being nominated based upon its natural heritage values. The most significant natural heritage values of Three Rivers are outlined in section 5.1.
5.3 Natural Heritage Integrity
Purpose of this section: To describe how the rivers appear to meet the natural integrity guidelines.
As noted in section 5.1, Three Rivers has natural values that are clearly significant in a provincial context, but less so nationally. As is typical of most of Prince Edward Island, Three Rivers is a heavily altered landscape. The strength of the natural values integrity appears to be lower than that for the cultural or recreational values. That is not meant to suggest that there would be no benefit in conservation and promotion of the natural values of Three Rivers. As with all the above identified values of Three Rivers, there is strong potential for maintenance, improvement and enhancement of natural values through wise management. Every effort should be made to highlight these values and enhance them where possible through management plan considerations. It is recognized that a healthy, natural environment is vital to sustaining recreational and cultural values for the Three Rivers.
|
Designed by SueB |
Next