Project Spotlight: Oliver Denny – Using nematodes as bioindicators

Ponderosa Pine/Bluebunch wheatgrass Reference Site at Kenna Cartwright Park


Ponderosa Pine/Bluebunch wheatgrass ecosystems are threatened by multiple stressors, including the spread of invasive species, and it can be difficult to prioritize sites for restoration treatments. Soil nematode communities respond to ecosystem disturbances, which allows us to use nematodes as bioindicators. My study links the observed nematode community with established indices, allowing nematode analysis to be used as a tool for assessing ecosystem health.

Study site:

My project takes place in Kenna Cartwright Park, located in Kamloops B.C. The park is within the PPhx zone, classified as a very dry and very hot climate with Ponderosa Pine and Bluebunch wheatgrass as the dominant vegetation. It is a beautiful park and heavily used for hiking, mountain biking, and horseback riding. Much of the park ecosystem is dominated by big sage (Artemeisia tridentata) and bluebunch wheatgrass (Pseudoroegeneria spicata), however the southernmost part of the park is disturbed by the presence of invasive plants spotted knapweed (Centaurea stoebe) and dalmatian toadflax (L. dalmatica). The director of Kenna Cartwright park has expressed interest in finding efficient and novel methods to limit the spread of invasive species throughout the park.



My experiment uses nematodes extracted from the soil from invaded and undisturbed test sites as bioindicators of ecosystem health, and resilience to invasion. Four of every five multicellular animals on the planet are nematodes; they occupy every  niche with available organic carbon and vary in sensitivity to pollutants and other disturbances. Traditionally nematodes have been studied in the field of agriculture as many nematode species are plant parasitic and destroy crops. Nematodes are now further understood as a complex part of the soil food web and various groups are be classified as “beneficial” or “detrimental” to specific crops.

Recently several indices have been developed that use the responses of nematode taxa to disturbances as a basis to analyze soil health and further assess the environmental system.  My experiment uses the Maturity Index (MI) and the Colonizer- Persister scale, or c-p scale. Once nematodes are extracted from a sample they are analyzed with a compound microscope. I count the total nematode community and categorize each species group. Then each group is given a value based on the appropriate index scale, for example a Dorylaimina nematode, a K strategist, is generally ranked 5 c-p.


Some challenges I have encountered in my data collection have been buggy (pun intended) equipment: it can be difficult to get consistent accurate soil moisture readings with soil probes. Also, using a hand auger to drill holes in hard clay/rock is time consuming, and tough work in the sun! In my experience, an expert is needed for learning how to identify and differentiate each nematode species, reading from a book can only go so far and finding guidance from someone with technical experience is a must.

Tools of the Trade: Soil Auger, Probe, Storage Bag, and Field Notebook (not pictured: GPS)

Preliminary results:

So far, I have found that sites disturbed by invasive plants spotted knapweed and dalmatian toadflax have less diverse nematode communities. These sites are dominated by ‘colonizer’ type nematode species. Comparatively, undisturbed bluebunch wheatgrass ecosystems have a similar abundance of nematodes, but nematode diversity is higher than disturbed sites. Furthermore, nematode communities in undisturbed sites are dominated by ‘persitor’ type species.


Restoration applications:

With the completion of my project, Kenna Cartwright Park could use nematode analysis to rank areas in the park by susceptibility to invasion: areas with ‘colonizer type’ species may be less resilient to invasive species than those with ‘persistor types’. This would let Kenna Cartwright Park to prioritize sites for restoration treatments (such as hand pulling, mowing, or fire) in the ecosystem.


Upcoming Event: ERSA Welcome Potluck

Join us Friday, September 7th at 5:30 at Guichon Creek at BCIT to  welcome new students in the program and to catch up with past and present students. There will be games, food, and an all-around good time to be had. We hope to see you there!


We will also be bringing some lawn games, so if you have bocce, croquet, frisbees, a slackline, or other fun games please bring them! We will post a games sign up sheet, so that we know who brought what and can make sure everyone gets their games back at the end of the night 🙂

New Comment (and Compliment) Box

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A beautiful handcrafted comment box has recently been added to the ERSA common room at SFU (TASC II room 7540) and all are encouraged to submit anonymous comments, suggestions and compliments.

These can be suggestions for ERSA (how things are run, major concerns, etc.) that you wish to keep anonymous. We hope this will provide another avenue for communication, transparency and accountability with our student council. As always, you are welcome to come talk to us directly.

The box has already been put to use and received its first bit of feedback, a compliment! The Comment Box will be opened and comments addressed each ERSA meeting. So if you have any comments, compliments or ideas you would like to share, give the Comment Box a try! Also feel free to contact ERSA through email found HERE

Project Spotlight: Ashleigh Westphal


My project involves working with CWS and its partners to determine how hydroelectric development in the West Kootenays may be impacting marsh bird populations. The Canadian Wildlife Service has been surveying marsh bird species in BC’s Southern Interior Mountains since 2010. These surveys focus on marsh bird species that tend to be more secretive in nature, therefore harder to observe and study. In the West Kootenay region, significant sections of the Columbia and Kootenay Rivers and their tributaries have been impounded or otherwise altered by hydroelectric projects. These projects alter the landscape and ecosystem processes in a variety of ways, altering vegetation communities, flood regimes, and nutrient cycling just to name a few. Additionally, large sections of the Creston Valley floodplain have been altered by agricultural development and diking. In 2016, surveys began in the Columbia Wetlands region of the East Kootenays. These wetlands are relatively unaltered and one of the longest intact wetland complexes in North America.


To get a better sense of how differences between regions relate to marsh bird populations, complementary habitat surveys at each survey station have been collected through the years. These surveys consider critical elements of the area which could influence whether birds are present, such as how much of the area is open water versus emergent vegetation. Finally, in 2018 aquatic invertebrate samples were collected at most survey stations. Ideally, these samples will provide a sense of how much food is available, either for the birds directly or generally within the base levels of the food web.

Field work always comes with its own challenges, especially when you are not familiar with your study areas. Invertebrate collection at several survey stations was difficult, as stations were not originally selected for that kind of sampling. Knowledge from those working locally who had been involved with the project for years was invaluable in my planning, as many stations were not safe or feasible to sample for invertebrates. Ultimately, I collected samples where it was possible and was able to get good overall representation of the regions. Early analyses are already showing that certain aspects of the habitat are more important than others, and this varies between species. These initial results are maybe not surprising but having a better understanding about how marsh bird populations and critical aspects of the ecosystem (vegetation communities, invertebrates, etc.) have been impacted can allow us to better tailor restoration efforts to support these species.


Resources: Where to get that ever-important professional development?

Are you looking for opportunities to build skills in data management, project management, and in the field? Workshops and volunteering are a wonderful avenue to do this! The Faculty of Environment (SFU) is hosting a workshop on September 22nd to guide conservation professionals and restoration practitioners in using the Open Source process to increase the efficiency and effectiveness of collaborative efforts of conservation management. To find out more and to register for the event, click here. In addition, the SFU Research Commons offers a variety of workshops to help you build skills in data management, GIS, and scientific writing. Alternatively, check out the College of Applied Biology website for upcoming certification courses to build your repertoire of qualifications in the field. Lastly, don’t forget about all the great skill-building opportunities available through your local ecological society, such as the Stanley Park Ecological Society (SPES).

ID’ing, and surveying, and radio telemetry! Oh my!

As we’ve learned throughout the year, timely monitoring paired with good science is key to developing a baseline of site conditions, and gauging success following restoration. We spent the first few weeks of May learning how to design and implement survey methods in terrestrial and aquatic environments. The first week, focused on terrestrial surveys, included small mammal trapping, radio telemetry, amphibian surveys, as well as bird and vegetation surveys. The highlight of the week was certainly trapping grey voles and deer mice in the old growth and secondary growth at Mission Tree Farm. Fish sampling and ID’ing, in situ water quality analysis, and the Fish Habitat Assessment Procedures (FHAP) were explored during the second week (aquatic). In addition to survey methods, we had our hand at log drilling and cabling. This is a restoration technique in which large woody debris is installed into a river to increase stream complexity for fish. Overall, I’d say those two weeks were an engaging, fun-filled, and great way to end year one of the program!

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Top left to bottom right: Newt caught with a Gee trap; Rock drilling; Grey vole; ID’ing juvenile salmonids; Log drilling; Pole seining; Fish caught in gill net; Tagging a deer mouse; Surveying for nests.