Introduction
You will find yourself in Campbell Valley Park, exploring an area that Metro Parks has been revitalizing by re-introducing ephemeral ponds.
This multi-year project began in 2015 and is designed to convert an area that was hayfelds and rental properties back into seasonal wetlands that support native plant and animal species.
When visiting this part of Campbell Valley Park, please be careful not to obstruct driveways or venture onto private property.
Starting at the first waypoint, walk the trails through the pond area (please stay on the trails) making observations as you go. The questions you need to answer in order to successfully log this Earthcache are found at the end of the description. Please note that "found it" logs not supported by the Earthcache answers (in a separate email or Geocaching.com Message Centre message) may be deleted.
In addition, there is important information contained within the description of this Earthcache page that will assist you in answering the questions.
What is an Ephemeral Pond?
Ephemeral ponds, or vernal pools or ponds, “...are temporary pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe development of natal amphibian and insect species unable to withstand competition or predation by fish.”
https://en.wikipedia.org/wiki/Vernal_pool
Where’s the Water?
Ephemeral ponds generally are filled by surface runoff, but by their very definition, are often dry. Depending on the time of year, and what the weather has been like at the time of your visit, you may find the pond system here in varying states.
As you walk between the waypoints, you should notice that the ponds have an almost “tiered” style of construction using mostly natural materials.
At the points where the ponds empty to the next stream or pond, there are specific water flow controls in place. These are called weirs. A weir has some specific benefits to the ephemeral ponds in this area.
First, they control the rate of flow of water from pond to pond, ensuring that a certain amount of water will remain through the wet season.
Second, because a weir slows the velocity of the upstream water, it increases siltation of the water, creating a beneficial environment for the insect and amphibian species the ponds have been built to accommodate.
Why Build Them?
Ephemeral ponds and streams have disappeared fastest of all pond types from the Fraser Valley and Greater Vancouver area because they are the shallowest and therefore easiest for farmers and land developers to fill in.
These ponds provide habitat for frogs, salamanders, newts, and other macroinvertebrates, as well as many species of plants and insects. A very important aspect of these ponds specific to our area, is that the invasive species of American Bullfrogs can’t survive in ephemeral ponds because they need 2 years of water to mature.
The construction of these geological features that are normally naturally occurring and once were very common to our area, is important to re-introduce an ecological balance to a rapidly developing Greater Vancouver area.
Metro Parks, with some help from volunteers including Metro Vancouver Geocachers, has been hard at work over the past couple of years to reconstitute this area into a series of ephemeral ponds and pollinator meadows. Enjoy your visit!
QUESTIONS:
Q1 - What is another name for an ephemeral pond?
Q2 - Why are these ponds considered ephemeral?
Q3 - What invasive species to this area cannot survive in ephemeral ponds?
Q4 - How is the water flow between the ponds being managed, and why is this method both beneficial and similar to how the ponds would form naturally?
Q5 - How many distinct ephemeral ponds are there in this area?
Q6 - At the time of your visit, how many of the ponds contain water?
Q7 - Does this geologic feature occur naturally in Greater Vancouver, and why might they be difficult to find?
RESOURCES:
Metro Parks
http://www.metrovancouver.org/services/parks/learn/projects-and-initiatives/cambpell-valley-ecological-enhancement/Pages/default.aspx
Univeristy of Wisconsin-Stout
Dr. Mandy Little
Associate Professor of Biology
littlea@uwstout.edu
Dr. Jim Church
Lecturer in Biology
churchjam@uwstout.edu