Thursday, May 23, 2019

Sensitive ecosystem loss in Metro Vancouver and the South of Fraser

The Metro Vancouver Regional District has been tracking the loss of sensitive ecosystems and modified ecosystems since 2013. Last summer, the district released region-wide loss statistics which showed that 426 hectares of mature forests, wetlands, and riparian riverbank areas in the Metro Vancouver core had been lost between 2013 and 2018. I posted about this last summer where I noted that this loss was three times the size of all parkland in Langley City! The regional district recently released more detailed analysis and a sub-regional breakdown of sensitive and modified ecosystem loss in that time period.

Two critically sensitive ecosystem types in Metro Vancouver are wetlands and riparian riverbank areas. 120 hectares of our wetlands were lost, and 96 hectares of riparian areas were lost even with seemingly strict regulations. The follow charts shown the reasons for the loss.

Causes of loss for wetland ecosystems in Metro Vancouver. Select chart to enlarge.

Causes of loss for riparian ecosystems in Metro Vancouver. Select chart to enlarge.

One of the things that surprised me was the amount of loss caused by our transportation and communication networks.

While only 7% of all sensitive or modified ecosystems in Metro Vancouver are in the South of Fraser, 33% of the loss of these ecosystems in our region occurred in the South of Fraser which includes Surrey, White Rock, and Langley. 19% of all land in the South of Fraser is considered sensitive or modified ecosystem.

Proportion of regional sensitive or modified ecosystems found within the South of Fraser. Select chart to enlarge.

Proportion of regional loss that occurred within the South of Fraser sub-region. Select chart to enlarge.

The top 3 types of sensitive or modified ecosystems in the South of Fraser are:

  1. Riparian (Sensitive): 4,735 ha
  2. Young Forest (Modified): 2,164 ha
  3. Wetland (Sensitive): 1,952 ha

568 hectares of sensitive or modified ecosystems were lost in the South of Fraser between 2013 and 2018. Of that loss, about 54 hectares was mature forest which is considered a sensitive ecosystem. Modified ecosystem loss included young forests (184 hectares) and old fields (270 hectares).

The top causes of the loss of these ecosystems in the South of Fraser were agriculture, clearing, mowing, and residential development.

In Langley City, we recently strengthen our regulations around development near environmentally sensitive areas. It may be time for other municipalities and the provincial government to do the same to prevent further loss of sensitive ecosystems in Metro Vancouver.

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