Sensitive Ecosystems Inventory (SEI)

An ecosystem is a portion of the landscape with similar dominant species and non-living features that share similar energy flows and nutrient-cycling processes. An ecosystem’s species include all terrestrial and aquatic life forms and micro-organisms.

Sensitive Ecosystems act as habitat oases for species and ecological communities at risk, and they have one or more of the following characteristics:

• Few examples exist or they are limited to only a few areas.
• They have high biodiversity and many interconnected native species.
• They are critical habitat for rare species.
• They are fragile and sensitive to disturbance and human activity.

The Sensitive Ecosystem Inventory (SEI) is a method created by the BC Ministry of Environment to systematically identify and map at-risk and ecologically fragile terrestrial ecosystems, according to the biodiversity they support. The purpose of an SEI is to encourage land use decisions that protect sensitive ecosystems.

Sensitive Ecosystem mapping is based on classification of sites that share similar climate, vegetation, soil, and moisture characteristics. SEI creates thematic maps that provide an area-inventory of rare, fragile, and biologically diverse ecosystems. DIEM’s SEI categorized ecosystems using methodology defined by BC’s Conservation Data Centre, and the maps were created using 1:20,000 scale air photos and GIS modelling of topographic, terrain, vegetative, fresh water, and intertidal bathymetric information. Ecologists later field-verified 20% (2,252) of the SEI polygons to confirm the digital interpretation and collect additional ecological information.

Sensitive ecosystem maps are used to identify the locations of sensitive ecosystems and provide a guide for planning in specific sites. Sensitive Ecosystems that have been mapped for the Discovery Islands are: Intertidal (IT), Estuarine (ES), Sparsely Vegetated (SV), Herbaceous (HB), Woodland (WD), Riparian (RI), Freshwater Ponds & Lakes (FW), Old Forest (OF); Karst (KA). Other important ecosystems are Young Forest (YF) and Mature Forest (MF).

Protecting sensitive ecosystems contributes to healthy biodiversity and the recovery of rare ecological communities and species-at-risk. Planning for ecosystem-connectivity can also help prevent species from becoming at risk, especially during a time of climate change.