Ecosystems
What is an ecosystem?
An ecosystem refers to a community of living organisms (like plants, animals, and insects) and their interactions between each other and the physical environment around them.
Ecosystems are diverse, and unique. Their combinations of plants, animals and their physical environment defines the beauty and richness of the natural world. Maintaining this natural diversity is key to preventing species extinctions and is a critical aspect of maintaining natural resilience into the future.
Ecosystems in the Cowichan Valley
The Cowichan region contains a range of rare and sensitive ecosystems that have very high ecological and social values. The majority of the region’s population is within the Coastal Douglas-fir Biogeoclimatic Zone of Vancouver Island. The climate of this zone is often characterized by warm, sunny summers and mild, wet winters. Unlike more exposed coastal areas such as the west coast of Vancouver Island, our zone experiences long dry summers, which are a major factor in its ecology. The Coastal Douglas-fir Zone is home to a unique and sensitive group of ecosystems, and includes seaside parkland, dry forest, rock outcrop, and wetland habitats and contains many rare plants. The area is home to many estuaries, where rivers and streams flow into the sea, which provide habitat for a variety of life. Ecosystems in our region can be categorized into three main groups: terrestrial, marine, and freshwater.
A terrestrial ecosystem is a land-based community of organisms and the interaction of biotic (living) and abiotic (non-living) components in a given area. Terrestrial ecosystems are areas of similar soil, topography and climate – but can be defined at many different scales. The Cowichan Valley is home to a number of unique terrestrial ecosystems, including Garry oak woodlands, old growth forests, riparian areas, and more.
Climate change has an impact on our terrestrial ecosystems. Warmer temperatures may affect the timing of biological cycles, enhance the potential for invasive species, pests, and others that compromise native species in the region.
Learn more about our region's environmentally sensitive areas by visiting our Environmentally Sensitive Areas page.
Additional Resources:
- National Geographic: Terrestrial Ecosystems
- CVRD State of the Environment Report: 2.1: Landbase (2010)
- CVRD State of the Environment Report: 2.2: Sensitive Ecosystems (2010)
- An Inventory of Environmentally Sensitive Areas within the Cowichan Region (2018)
- Developing an Environmentally Sensitive Area Strategy for the Cowichan Region (2018)
- Environmentally Sensitive Areas (ESAs) Mapping in the Cowichan Region - Phase II (2018)
- Terrestrial Biomes and Ecosystems [VIDEO]
Marine ecosystems are aquatic environments with high levels of dissolved salt. Examples of marine ecosystems are the open ocean, the deep-sea ocean and coastal marine ecosystems, each of which has different biological and physical characteristics.
Climate change, land use change, and industry all pose various challenges to marine ecosystems, and can impact their health and biodiversity.
Shoreline ecosystems, which interface between terrestrial and marine environments, are considered sensitive. Many marine species inhabit the intertidal zone for some or all of their life history--including crab, shellfish, and forage fish. Species in intertidal zones are important species in the marine food web, and can feed a diversity of bird species to marine mammals. Estuaries are special areas of extremely high-value shoreline. Their location at the intersection of the terrestrial, aquatic and marine environments results in very high productivity and biodiversity values. These ecosystems are threatened by modification due to human activities, and are vital to protect and restore.
Additional Resources:
- National Geographic: Marine Ecosystems
- State of the Environment Report: 2.2: Sensitive Ecosystems (2010)
- Royal BC Museum: How is Climate Change Affecting Marine Life in BC?
- UBC: Marine Ecosystems
- An Inventory of Environmentally Sensitive Areas within the Cowichan Region (2018)
- Developing an Environmentally Sensitive Area Strategy for the Cowichan Region (2018)
- Environmentally Sensitive Areas (ESAs) Mapping in the Cowichan Region - Phase II (2018)
Freshwater ecosystems are aquatic environments with low salt concentration, typically less than 1%. The plants and animals that live in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration, such as marine ecosystems. Examples of freshwater ecosystems are lakes, rivers, streams, springs, ponds and wetlands.
The Cowichan Valley is renowned for its lakes and rivers, which support a variety of fish and wildlife. Climate change, land use, and pollution are all threats to water quality and quantity, which can directly impact freshwater ecosystem function. Healthy freshwater ecosystems are linked to healthy overall watersheds. Learn more about what we are doing to protect the region's freshwater ecosystems by visiting our water quality, water supply, and watersheds webpages.
Additional Resources:
- National Geographic: Freshwater Ecosystems
- CVRD 2010 State of the Environment Report: 2.5: Fish
- CVRD 2010 State of the Environment Report: 2.6: Water
- An Inventory of Environmentally Sensitive Areas within the Cowichan Region (2018)
- Developing an Environmentally Sensitive Area Strategy for the Cowichan Region (2018)
- Environmentally Sensitive Areas (ESAs) Mapping in the Cowichan Region - Phase II (2018)