ECOSYSTEMS AND HABITATS AT ISLAND VIEW BEACH REGIONAL PARK Updated: April 9, 2015
The Dune/Beach/Spit Complex
Ecosystems and Habitats
This section will cover terrestrial ecosystem mapping (TEM) and related habitat themes: •
A general description of dune, coastal marsh and old field habitats.
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Background on TEM as a standardized mapping approach.
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Deriving interpreted habitat maps.
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The effect of cultural history on ecosystems.
Dune Ecosystems
Dune Ecosystems Plant communities on coastal sand ecosystems shift as you move away from the influence of the sea. The primary drivers are salt, moisture and wind. Sand in the fore dunes is the least stable habitat and only specialized plants can thrive there. Many of these harsh unstable sites can provide critical habitat for rare or uncommon species. As you move shoreward, the sandy substrate becomes more stable, vegetation cover and diversity increase, and you see changes in both soil moisture and nutrients. Further upland, species diversity can decrease as you move into forested land. These associations are classified and mapped as ecosystems. Adapted from: http://greenfieldgeography.wikispaces.com/IGSE=Coasts+and+GCSE+Coasts
Dune Ecosystems
Beach Flat/Low Dune
Fore Dune
Dune Slack
Backshore and Wooded Mature Dunes
Dune Ecosystems These are typical ecosystems you see at Island View Beach Regional Park: •
Beach flats and low dunes near the shore are devoid of vegetation.
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Low fore dunes like this example are covered by dune grass.
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Backshore dune slacks where saltgrass and standing water can be seen.
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In the far backshore, the stable mature dunes and bluffs are forested with tall shrubs and then trees as you move upslope.
Stacey and Filatow. 2000. Terrestrial Ecosystem Mapping of TIXEN/Cordova Spit Final Report. Unpublished Manuscript. CRD Regional Parks. 89 pp.
Coastal Wetlands
Coastal Wetlands Dune habitat dominates the immediate backshore at Island View Beach Regional Park but most of the park is low lying wetland and old fields. Groundwater is at or near the surface throughout the year forming a complex of habitats. These definitions may help to understand the different components: •
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A marsh forms a transition between aquatic and terrestrial ecosystems and is dominated by grasses, rushes or reeds. If woody plants are present they tend to be low-growing shrubs. Wet meadows occur on the land between shallow marshes and upland areas. Wet meadows often have very high plant diversity and are regularly flooded but often dry in the summer. Under the current drainage regime at Island View Beach Regional Park, much of the landscape is wet meadow habitat. Salt marshes are found where a marsh is influenced by the tides through groundwater intrusion or surface flow. They are sporadically covered with water and are most commonly found in lagoons, estuaries, and on the sheltered side of a sandspit or beach berm.
These features are important to the Tsawout First Nation for food gathering, medicines and other cultural purposes. They are also important habitat for birds, amphibians and small mammals as well as a high diversity of plants. Adapted from: USGS Public Domain Graphics
Wetland Ecosystems
Brackish Meadow (silverweed)
Old Field (seasonal flooding)
sea asparagus
Brackish Woodland
Salt Marsh (saltgrass)
Wetland Ecosystems These are typical wetland ecosystems you see at Island View Beach Regional Park. They are often defined by salt-tolerant vegetation. Brackish meadows:
Potentila egedii (silverweed).
Old Fields: a mix of agronomic pasture grasses and native species including Distichylis spicata (saltgrass). Brackish woolands: Juncus articus (Arctic rush) blends into Rosa nootkana (Nootka rose). Salt Marsh: Dominated by salt grass and salicornia virginica (sea asparagus). Stacey and Filatow. 2000. Terrestrial Ecosystem Mapping of TIXEN/Cordova Spit Final Report. Unpublished Manuscript. CRD Regional Parks. 89 pp.
Terrestrial Ecosystem Mapping (TEM)
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International standards Mapping- 2008 • 61 map units • 39 field plots
•11 “in the park”
• 21 ecosystem types •15 “in the park”
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Complex data has many uses
Terrestrial Ecosystem Mapping Terrestrial Ecosystem Mapping (TEM) follows international standards to classify landscapes by reflecting differences in climate, geology, landform, soils and vegetation. High resolution photo interpretation is used. The photo scale is 1:15,000 (1mm on the photo equals 15m on the ground). Areas of common characteristics are separated with lines to create polygons and ground plots are established in the field to confirm findings. Although a mapping technician strives for pure polygons, complex polygons are often created to reflect the patchiness of a natural landscape. Although we put hard lines on a map for classification, the landscape varies continuously. The data can be combined with other information and summarized for conservation planning, communications and education, risk assessment and emergency response planning. Ecosystem mapping was conducted in 2008 by the BC Ministry of Environment including the larger Cordova shoreline surrounding the park. Sixty one polygons or unique areas were mapped with 39 field plots and 21 ecosystem types. The park makes up about 1/3 of the area mapped and contains 11/39 plots and 15/21 described ecosystem types. Stacey and Filatow. 2009. Terrestrial Ecosystem Mapping of TIXEN/Cordova Spit Final Report. Unpublished Manuscript. CRD Regional Parks. 89 pp.
Terrestrial Habitat
Terrestrial Habitat Using a geographic information system (GIS) you can combine attributes to highlight the features you are most interested in. This map is an interpretation depicting the dominant habitat types that occur across the landscape of Island View Beach Regional Park. Yellow: sand flats are along the beach in yellow. Pink: is the shrubby dune habitat described in the previous slide. We know that this area is predominantly shrubby dunes but open dune habitat (orange) is also part of this zone. Orange: these areas show the transition to a more open herbaceous habitat toward the northern park boundary (north of the artificial berm). The backshore is a complex of brackish meadow and woodlands shown as green zones on this map. These habitat boundaries reflect elevation. The lower areas are meadows in summer and are seasonally flooded during the winter. The bright green zone to the top left of the map is wetted at or near the surface for most of the year and is dominated by salt-tolerant vegetation. Take note of the sinuous nature of the backshore boundaries and the more linear or abrupt boundaries toward the southern end of the park. These will be explored in the next few slides.
Elevation Model
Land at or below a moderate tide Elevation 2.4 m above mean sea level (amsl)
Elevation Model The sinuous meadow and marsh habitat boundary is reflected very closely by the low elevation areas that are subjected to high water table, seasonal flooding and high salinity. Using LiDAR data, this image depicts land elevations that are below a 2.4 m tide. This reflects a moderately high tide for this area. The low lying areas in the backshore are affected by the high water table and the vegetation reflects that.
Land Use History
Old Field Pasture Transferred to Park 1966
Old Field Pasture Transferred to Park 1992
Old Field Cultivated Transferred to Park 2010 Active Field Cultivated Mowed 2014
Land Use History We spoke about the sinuosity of low lying habitats but not the linear transitions. These reflect the human element of landscape change. Island View Beach was managed for thousands of years by the Tsawout people and continues to be important to them. The backshore wetlands provide resources such as plants for medicine, food and technology; and waterfowl or deer for hunting. The beaches provide nearshore marine resources for seafood, transportation (canoes), recreation and other cultural activities. In the past 150 years or so, many people have come to this area to settle. Island View Beach has been influenced by the local agricultural community and more recently has become an important recreational site for the region. The long history and hard work of settlers in this area to maximize agricultural use of this land is still evident today. If you look at the park landscape from north to south, there are subtle changes in texture and pattern that correlate with old property boundaries and land use changes like cultivation. Page, N. 2010. Cordova Shore Conservation Strategy. Unpublished report prepared for CRD Regional Parks, Tsawout First Nation, and Canadian Wildlife Service. 66 pp + appendices.
Ecosystems and Habitats Summary Island View Beach Regional Park is dominated by dune, coastal marsh and old field habitats. TEM is a standardized mapping approach representing physical and biological features. Interpretation is limited by scale and resolution. Terrestrial ecosystems of Island View Beach Regional Park reflect the dynamic processes of a coastal landscape. Cultural history affects ecosystem expression and function.