Monitoring northern biodiversity: picking the right trap for collecting beetles and spiders

Ecological monitoring is an important endeavour as we seek to understand the effects of environmental change on biodiversity. We need to benchmark the status of our fauna, and check-in on that fauna on a regular basis: in this way we can, for example, better understand how climate change might alter our earth systems. That’s kind of important.

A northern ground beetle, Elaphrus lapponicus. Photo by C. Ernst.

A northern ground beetle, Elaphrus lapponicus. Photo by C. Ernst.

With that backdrop, my lab was involved with a Northern Biodiversity Program a few years ago (a couple of related papers can be found here and here), with a goal of understanding the ecological structure of Arthropods of northern Canada. The project was meant to benchmark where we are now, and one outcome of the work is that we are able to think about a solid framework for ecological monitoring into the future.

A few weeks ago our group published a paper* on how to best monitor ground-dwelling beetles and spiders in northern Canada. The project resulted in over 30,000 beetles and spiders being collected, representing close to 800 species (that’s a LOT of diversity!). My former PhD student Crystal Ernst and MSc student Sarah Loboda looked at the relationship between the different traps we used for collecting these two taxa, to help provide guidelines for future ecological monitoring. For the project, we used both a traditional pitfall trap (essentially a white yogurt container stuck in the ground, with a roof/cover perched above it) and a yellow pan trap (a shallow yellow bowl, also sunk into the ground, but without a cover). Traps were placed in grids, in two different habitats (wet and “more wet”), across 12 sites spanning northern Canada, and in three major biomes (northern boreal, sub-Arctic, and Arctic).

Here’s a video showing pan traps being used in the tundra:

Both of the trap types we used are known to be great at collecting a range of taxa (including beetles and spiders), and since the project was meant to capture a wide array of critters, we used them both. Crystal, Sarah and I were curious whether, in retrospect, both traps were really necessary for beetles and spiders. Practically speaking, it was a lot of work to use multiple traps (and to process the samples afterwards), and we wanted to make recommendations for other researchers looking to monitor beetles and spiders in the north.

The story ends up being a bit complicated… In the high Arctic, if the goal is to best capture the diversity of beetles and spiders, sampling in multiple habitats is more important than using the two trap types. However, the results are different in the northern boreal sites: here, it’s important to have multiple trap types (i.e., the differences among traps were more noticeable) and the differences by habitat were less pronounced. Neither factor (trap type or habitat) was more important than the other when sampling in the subarctic. So, in hindsight, we can be very glad to have used both trap types! It was worth the effort, as characterizing the diversity of beetles and spiders depended on both sampling multiple habitats, and sampling with two trap types. There were enough differences to justify using two trap types, especially when sampling different habitats in different biomes. The interactions between trap types, habitats, and biomes was an unexpected yet important result.

Our results, however, are a little frustrating when thinking about recommendations for future monitoring. Using more than one trap type increases efforts, costs, and time, and these are always limited resources. We therefore recommend that future monitoring in the north, for beetles and spiders, could possibly be done with a trap that’s a mix between the two that we used: a yellow, roof-less pitfall trap. These traps would provide the best of both options: they are deeper than a pan trap (likely a good for collecting some Arthropods), but are yellow and without a cover (other features that are good for capturing many flying insects). These are actually very similar to a design that is already being used with a long-term ecological monitoring program in Greenland. We think they have it right**.

A yellow pitfall trap - the kind used in Greenland, and the one we recommend for future monitoring in Canada's Arctic.

A yellow pitfall trap – the kind used in Greenland, and the one we recommend for future monitoring in Canada’s Arctic.

In sum, this work is really a “methodological” study, which when viewed narrowly may not be that sexy. However, we are optimistic that this work will help guide future ecological monitoring programs in the north. We are faced with increased pressures on our environment, and a pressing need to effectively track these effects on our biodiversity. This requires sound methods that are feasible and provide us with a true picture of faunal diversity and community structure.

It looks to me like we can capture northern beetles and spiders quite efficiently with, um, yellow plastic beer cups. Cheers to that!


Ernst, C, S. Loboda and CM Buddle. 2015. Capturing Northern Biodiversity: diversity of arctic, subarctic and northern boreal beetles and spiders are affected by trap type and habitat. Insect Conservation and Diversity DOI: 10.1111/icad.12143


* The paper isn’t open access. One of the goals of this blog post is to share the results of this work even if everyone can’t access the paper directly. If you want a copy of the paper, please let me know and I’ll be happy to send it to you. I’m afraid I can’t publish all of our work in open access journals because I don’t have enough $ to afford high quality OA journals.

** The big caveat here is that a proper quantitative study that compares pan and and pitfall traps to the “yellow roof-less pitfall” traps is required. We believe it will be the best design, but belief does need to be backed up with data. Unfortunately these kind of trap-comparison papers aren’t usually high on the priority list.

How are you doing? Perhaps not “fine”?

When asked “how are you”, many people give a default answer of “fine”. Although that may be true a lot of the time, I worry that not everyone is “fine” all of the time. In my experience, this is especially true at this time of year: the late autumn can be tough on a lot of people, as the semester is no longer new and exciting, and the dark days of November* are ahead.

I’m involved with a lot of initiatives on campus around ‘wellness’ of our community, from mental and physical health, through to trying to best understand our campus resources, and think about ways we can be proactive around well-being. Part of my goal is to increase awareness of services and resources available to everyone, and to ‘check in’ with people as we enter a difficult time of year.

I decided to write a letter to our community, but a member of our communications team suggested a video message may also help to increase awareness. So, here’s the video. It’s low-tech and done without a script, but perhaps the message is relevant to your own community. Please share if that’s the case.


*I personally find November rather tough. A few years ago my amazing and insightful wife suggested I take a photo every day in November, to explore the beauty that the month has to offer. That helped me a lot, and I’m immensely grateful for her suggestion to see beyond the dreariness to embrace colour and texture. Honestly, I think that project helped me with my own mental health, and I no longer dread November to the same degree.


Ecology from geology

I recently asked a geologist* to come to speak to my field biology class. The course is about the “St Lawrence Lowlands“, and throughout the term we visit farms, forests, lakes and streams, and we do natural history research.

Why then, do I have a geologist come and speak to us?

A result of glacial till: it's now supporting biodiversity.

A result of glacial till: it’s now supporting biodiversity.

Ecology is built upon geology. This may seem obvious, but requires a deeper discussion: after hearing this guest lecture year after year, I no longer see my local landscape as some farm fields, patches of forests, and some big bodies of water**. I see lands and waters shaped by a history before our time. The local landscape is a product of past geological events. We have farm fields around the Montérégie because the Champlain Sea deposited its sediments and after it departed; what remained is a flat expanse, perfect for farming. As the sea departed, it left behind remnants of beaches still visible today, as the Plateau district of Montreal, or where apple orchards grow next to Mont St Hilaire. We have some slight elevation here and there because of sandy deposits left by the departure of the last great glacier that covered our land in the very recent past. That’s where we find great white pines, stretching up above the canopies of the deciduous trees. We have Mount Rigaud because of processes hundreds of millions of years ago: an igneous intrusion that happened long, long before the age of dinosaurs. More recent igneous intrusions created the Lachine rapids, historically important as this became a key place where First Nations people, and later Europeans, set up camp along their journey up or down the big river. This was the one of the birthplaces of Montreal.

Our landscape, and the ecology of our landscape, is built upon slow but incredible processes, and I think biologists don’t consider those processes as dynamic forces that are constantly influencing our current view of the world. Ecologists often think of time in scales of decades or centuries, and we spend considerable time looking at time frames that resonate with our own life spans (in contrast, evolutionary biologists and taxonomists look much further back, and are accustomed to time frames of ‘millions of years’. I think We need to meet in the middle a little more).

As field biologists, knowing the origin of those big rocks in the forest matters a great deal: glacial till from the past creates habitats today. Moss creeps on these ancient boulders; centipedes and spiders crawl underneath. Their ephemeral life depends on much longer time frames. It’s hard to imagine how to consider discussion land management or wildlife conservation in the region without appreciating how past geological events can either help or hinder the process. There’s a geological reason why soil development is slow in some parts of our local ecosystems; why the land may be rocky, and why it’s well-drained in some areas, and wet in others. This affects long-term planning around wildlife preserves, or housing developments. There’s good reason why Mont St Hilaire is a biosphere reserve, and how it’s flora and fauna will be different that what we find elsewhere in the St Lawrence Lowlands.

Hiking at Mont St Hilaire: there are so many reasons why it's a special place, including geology.

Hiking at Mont St Hilaire: there are so many reasons why it’s a special place, including geology.

The longer I spend living here and learning about my region’s natural history, the more I recognize the value of some knowledge about geology, and this is why I have a geologist give a guest lecture. The students also tell me, year after year, that they appreciate and value this perspective, and their understanding of this part of the world is enriched by a deeper discussion about ‘why’ the St Lawrence Lowlands exists as it does.

How often do ecological classes include discussion about geology? Perhaps not often enough.

*the geologist in question is Dr. George McCourt, who teaches often in the McGill School of Environment. I am immensely thankful for him taking time to teach us about his passion.

**when I commute to work, this is what I see: forests, field and lakes. Others in the St Lawrence Lowlands will have a different story, perhaps one that involves highrises and concrete.

Landscape structure, insect herbivory, and ecosystem services

I’m pleased to announce a new publication to come out of the lab, with lead author Dorothy Maguire and co-authored by Elena Bennett and Patrick James. In this work, Dorothy ponders and writes about the broader implications of insect herbivory. More specifically, how insect herbivory is affected by landscape connectivity (i.e., the degree to which habitats are linked to each other), and how plant-feeding insects may relate to ecosystem services (i.e., the values and services that humans get from our natural systems).

Female (l) and male (r) Gypsy moth, caught in the act.

Important insects when, as caterpillars, eat a lot of foliate: Female (l) and male (r) Gypsy moth, caught in the act.

We certainly know that insects can do all kinds of damage to plants in ecosystems, but do insects in more (or less) connected habitats do more damage? To address this question Dorothy scoured the literature and got the relatively unsatisfactory answer of “sometimes”: 49% of the papers suggest increased connectivity relates to more insect herbivory and 28% of the papers show less herbivory in more connected patches. The lack of a clear answer actually makes quite a bit of sense since every context can be quite different, and not all insects are equal. It is hard to generalize since effects in forests will not be the same as in fields, and insects that are out-breaking (i.e., with major population explosions) may be affected differently than non out-breaking species. Dorothy certainly found these contexts were important. The results were important to illustrate how we need to adapt any management options with close attention to both landscape feature and their interaction with the life-history of the herbivore.

The second part of Dorothy’s work delved deeper into the literature to ask about the effects of out-breaking versus non out-breaking herbivore species on a select suite of forest ecosystem services: effects on timber production, aesthetics, soil formation and Carbon sequestration. There were some interesting results of this and again, any particular effect of herbivory on an ecosystem service was highly sensitive to the outbreak status of the herbivore. For example, the aesthetics of a forest can be positively affected by low levels of herbivory since this may help create pleasant conditions for light infiltration to the forest floor. However, an out-breaking species may defoliate a tree more completely, thus reducing the aesthetic value. Another example is that low levels of herbivory may positively affect timber production because trees may show “compensatory” growth after light feeding by an insect. In contrast, timber production will be negatively affected by high levels of defoliation as this may reduce a tree’s ability to grow. Although some of these results may seem rather logical, Dorothy’s work was unique as it showed how the scientific literature supports the connections between a herbivore’s life-history and key ecosystem services.

Screen Shot 2015-06-11 at 6.55.21 AM

Visual representations of the hypothesized relationships between insect herbivory and ecosystem services. Specifically (a) timber production, (b) aesthetic value of forests. Graphs are divided into four sections representing positive and negative effects of herbivory on ES, during non-outbreak (low) vs. outbreak (high) levels of herbivory. Quadrants are coloured differently based on the hypothesized strength of the effect of herbivory on ES: weak (light grey), moderate (dark grey) and strong (black). Proposed relationships are derived from synthesis of the available literature. From Maguire et al.

The last part of the work was focused on building a conceptual framework – a framework that ties together landscape structure, the process of herbivory, and ecosystem services. This is meant to be a road map for any stakeholders with an interest in any or all of those factors. For example, should a forest manager be tasked with understanding how to increase or support a particular ecosystem service, she or he needs also to recognize how that service is tied to important processes such as herbivory, and the related connections to the broader landscape.

Screen Shot 2015-06-11 at 7.05.34 AM

This work is novel and important because it links the well known process of insect herbivory to concepts of ecosystem services and to the discipline of landscape ecology. The marrying of these areas is critically important as we face increasing pressures on our natural systems, and the complexity of the systems can be overwhelming. We hope this work piques more interest in this topic, and that the framework Dorothy provides is useful to all the stakeholders.


Maguire, DY, PMA James, CM Buddle & EM Bennett Landscape connectivity and insect herbivory: A framework for understanding tradeoffs among ecosystem services. Global Ecology and Conservation. doi:10.1016/j.gecco.2015.05.006


The Challenges and Opportunities of University Administration: reflections from a Deanlet

A “Deanlet” is a cutesy name for an Associate Dean. I have no idea who came up with this title, but I first heard it from Terry McGlynn about a year ago, just before I started my first year as an Associate Dean of Student Affairs. Yes, it’s been a year. A very quick and exciting year. And a year is a good point to stop, pause and reflect on life as an Associate Dean*.

An Associate Dean is a level of the university administration just below a Dean (who typically oversees a Faculty). A Deanlet helps run a Faculty because there are too many bits and pieces for one person to handle. In my case, I oversee the affairs of undergraduate students in our Faculty (of which there are about 1,400 undergraduates). This includes recruitment efforts, aspects of student records, dealing with and helping students in academic difficulty, sitting on various committees at various levels in the University, working closely with my Faculty’s executive committee to help establish and oversee larger projects, and a myriad of other tasks (for example, reading names at convocation – something I get to do tomorrow!). In my role I spend a lot of time communicating and collaborating with students, staff, professors, and administrators. I see and experience many aspects of our Faculty.

So, let me report and reflect on three challenges with being a Deanlet, and three of the greatest opportunities that the position has offered me in the first year.


1) Perhaps the biggest challenge in my role has been learning how to help students in difficulty. Student wellness is a priority for me, but it’s not always easy to navigate and find the best solutions when students are struggling, and every situation is context-specific so few ‘generalities’ exist. Sometimes the struggles are academic, and sometimes they involve issues of mental or physical health. I’m often on the front line, and have to make difficult decisions: decisions that affect people. This can be stressful and difficult at times, and certainly means the work doesn’t always stay at the office. Thankfully I have received some excellent training, and have a great team to help, I feel supported, and I am gaining experience that will certainly help me into the future.

2) A second challenge is time management: I have meetings scheduled almost every day, and although they are worthwhile and important, they take time. I remain active as a teacher and a researcher, and I will continue to have a lab and teach my classes, but it can be difficult to balance everything. Before becoming a Deanlet I had a high degree of flexibility in my schedule, which is something many Professors value. However, that flexibility is much diminished, and it has required a lot of adapting. I have no regrets and I expected this (and no, I’m NOT complaining about how busy I am), but I would be lying if I didn’t state that this year has been a big adjustment. The other issue around time management is that when many hours are spent in meetings, this means squeezing other work into weird times of the day.

3) Being a Deanlet sometimes places me in a position of having navigate collegiality: being a colleague in one circumstance, but an Associate Dean in another, can be a challenge. I sometime have to make decisions that do not always please my colleagues (e.g., here’s a new policy XYZ that required you to change how you fill in paperwork XYZ), but also collaborate with my colleagues in research projects, in teaching and on committees. Another example is when a student brings an issue to my attention, perhaps in reference to a grade they received – I sometimes need to bring this to the attention of an instructor and these are not necessary simple or easy discussions. We are all adults, of course, but there is sometimes a divide between administrators and academics, and a professor who is an administrator (this is more-or-less the model at my institution) needs to be cognizant of the different hats, when to wear them, and how to strike the right balance. That being said, I can honestly say that my colleagues have truly been collegial. In my opinion, our institution runs relatively smoothly and effectively in part because our administrators keep one foot in the classroom and research lab.


1) It may sound cliché, but the best part of my Deanlet position is the people I get to interact with. A professor sees students in a classroom or research lab, and interacts with her or his peers, and certainly a Departmental chair, on a regular basis. A Deanlet gets to do this, and more: I see students for a suite of reasons (beyond teaching), and I meet Profs from many different corners of the University, largely because of the University-level committees I sit on. I also work in an office with *amazing* staff, who really run the show! These are individuals deeply committed to the University, and who have the students’ best interests in mind. A university runs well because of its staff, and the Deanlet appointment has afforded me very new and important perspectives on this. In general, Academic staff do not always appreciate the administrative and support staff, and the stresses and challenges they face. This is among the most valuable lesson that my Deanlet appointment has given me so far.

2) The second reason being a Deanlet is a great opportunity is because it places you in a position to understand the inner workings of a University. I have been able to see how the different arms of the University operate, and been in a position to compare and contrast operations in different Faculties with those in my own. It has allowed me wonderful insights into my institution, and allowed me to be an active player in the future directions of my Faculty, something I had hoped to do as part of this appointment. It is sometimes easy to criticize the ‘administration’ from the outside, but once being part of the process, I am much more sympathetic and sensitive to the reasons why some processes, policies and procedures are a certain way, and I am learning about how the system of collegiality at a University works to make change, and why that change sometimes takes time.

3) From a more selfish reason, a valuable gift of my Deanlet appointment is the constant learning it has provided: every day is different, there are always new projects, and the academic year brings different waves of activity, with each wave bringing its own sense of adventure. I’m the sort of person who thrives on variation, and thrives on new problems to solve, whether it be learning the finer points of a student assessment policy, or figuring out the best wording for recruitment materials. A University is a complex place, and delightful in this complexity. University Administration is another set of doors, levers and handles, and figuring out what they all do, and where they all go, is a good fit for me.

I hope this post provides some insights into the role of an Associate Dean in a University (don’t believe everything you read!). Of course, every University is different, and many of the challenges and opportunities will depend on institutional contexts and culture, but I would also think that some of the challenges and opportunities are relatively general (any Associate Dean’s out there wish to comment, below?). When others are afforded the opportunity for administrative appointments, I hope it’s considered seriously, as it’s certainly been a rewarding experience for me.

I will end with a sincere thanks to all the people who have supported me over the past year. The learning curve has been steep but my colleagues, staff, mentors, and my family have been patient and supportive. I’m excited and feeling ready for the years ahead.


* I’m not 100% sure why I wrote and published this post. And it was one that I wavered on for a while. However, I suppose it’s a way to time stamp my own thoughts, for selfish reasons – at the end of my term as a Deanlet, in four years from now, it will be interesting to see how my perspectives change. Perhaps it also because many people don’t know what a Deanlet does and I wanted to provide a glimpse into this portfolio.

Beetles from the North

I’m super-excited to announce new research from the lab, published yesterday with lead author Dr. Crystal Ernst.

Crystal’s paper focused on taxonomic and functional diversity of beetles across 12 sites in northern Canada, ranging from Labrador to the Yukon Territory, and from the bottom of James Bay all the way up to the tip of Ellesmere Island. This work is result of the Northern Biodiversity Program: a multi-institutional collaborative project about the ecological structure of northern Arthropods.

Crystal Ernst, on the tundra.

Crystal Ernst, on the tundra.

The paper was titled “Drivers and Patterns of Ground-Dwelling Beetle Biodiversity across Northern Canada” and in this research Crystal sorted and identified over 9,000 beetles from 464 species, and she classified the species by their functional ecology to assess how functional diversity may vary across the large spatial scale of this project. Instead of re-writing a summary here, I thought to use this blog post as an opportunity to reflect on what I see as the critical findings from this work, and why this is a paper that I’m incredible proud to be a part of.

  • To me, one of the more interesting findings of this work was that the functional diversity of beetles varied by latitude: although beetles do many things (e.g., herbivore, decomposers, carnivores), it doesn’t seem like all these functions happen at all latitudes. For example, although we document an impressive number of carnivores at all the sites, they are relatively more common in the more northern locations. This is a bit peculiar, and suggests that food-webs involving arthropods vary in some important ways depending on the biome. We also document that temperature is a major explanatory variable when considering functional diversity, which raises the important question about potential effects due to climate change. Indeed, should temperatures change in the north, this may affect the functional ecology of beetles, which in turn could affect other parts of the system.


Figure 1 from the paper: Fig 1. Map of the 12 study locations (North Pole Azimuthal projection), showing the spatial distribution of functional groups. These were pooled into trophic groups, and the pie charts show the proportion of the total site biomass represented by each trophic group

Figure 1 from the paper: Fig 1. Map of the 12 study locations, showing the spatial distribution of functional groups. These were pooled into trophic groups, and the pie charts show the proportion of the total site biomass represented by each trophic group

  • The research generally supported the well-known pattern in biogeography about how species richness decreases at more northern latitudes. When looking at which environmental variable may explain this pattern, temperature again came out on top. In other words, what beetles are found where is in part due to the temperatures in that region. Climate change scenarios therefore have significant potential effects on beetles in the north: beetles, like most other arthropods, are tightly linked to temperature. Even small changes in temperatures in the north may have big consequences for beetles.
  • One of the other big findings, to me, was the fundamental value of species-level data for an important taxa, across vast areas of Canada. Crystal recorded new Territorial and Provincial records for 15 beetle species, increasing knowledge about northern biodiversity. I’m also pleased that the data are fully available on-line, via Canadensys, so other researchers can access the information, re-analyze data, and benefit from and build upon this work.
  • The Arctic is special: it is a vast, cold, treeless landscape, with blankets of tundra, and permafrost underfoot. But it’s also special for beetles. After Crystal analyzed the community-level beetle data, using ordination methods, it became apparent that assemblages from the Arctic Islands of Canada were distinct from the sub-Arctic and north-Boreal sites. From a conservation perspective this is quite important. To some, the Arctic may come across as a big, ‘life-less’ region, with the odd polar bear roaming about, but in reality it hosts thousands of species, including hundreds of beetle species, and that beetle community is very different from what we find in other parts of North America. Special things deserve recognition and protection.
  • Every journalist I talked to has asked “Why beetles?” This is an easy one to answer: they fill virtually all roles in ecosystems, they are diverse, they are of interest to many people, and they are beautiful. The latter point is an important one, as it is important to capture curiosity and fascination about arthropods.


Carabus vietinghoffi. Photo by Henri Goulet.

A northern beetle: Carabus vietinghoffi. Photo by Henri Goulet.

In sum, this was a terrific project to be involved with, and our lab (and our collaborators) are thrilled that the efforts from the Northern Biodiversity program are showing up in the literature (for more examples, check out this, or this).

And rest assured, there’s more to come…

Earthworms at the Morgan Arboretum

This is a post written by undergraduate student Jessica Turgeon – she’s finishing up a project about earthworms.

When I was a child, you could always find me either in a tree or in the dirt. I liked to follow the ants up into the trees and back down again, where I would switch over to digging for earthworms. I loved the feeling of soil between my hands and thinking to myself that these little worms were responsible for making the soil the way it is. I now know that the process is a bit more complex than this but overall, five year old me was almost right.

JessicaI spent my whole life loving nature, especially those living in it. By high school I became a strong advocate for environmental protection, even helping a teacher create a bylaw in my municipality to stop parents from idling in front of elementary schools. This experience truly opened my eyes to the will power and determination this generation has when it comes to changing old mentalities about the environment.

When choosing a university to go to, there was no doubt in my mind whether I should apply to Environmental Biology at the Macdonald campus of McGill or not. This program combines both of my passions: nature and its diversity and environmental management. I’ve since embarked on an amazing journey that has shaped me as a person.

Being around so many naturalists rekindled my love for earthworms, so much so that I decided that I wanted to conduct a research project about them. With the help of Chris Buddle (McGill) and NSERC USRA, I decided to take on a project detailing their biodiversity at the Morgan Arboretum, a nearby forest.

Earthworms can greatly affect Southern Quebec soils because all of the species found here are invasive1. Forests have evolved without the help of earthworms, meaning that earthworm burrowing action is somewhat of a new experience for the trees1. The worms break up and mix the soil when they crawl, leaving the soil readily susceptible to erosion2. While earthworms are prized by gardeners as natural tillers, this can have drastic effects on hardwood forests2.

It was important to me to find out where certain earthworms were in the Morgan Arboretum and why they were there. Soils vary in their composition and properties, meaning that some are more suitable for earthworms than others. The goal of my project was to analyze three different soil types (sandy, clay, loam) with regard to earthworm species. I did so by sampling in the three soils and by collecting and analysing the soil using basic soil analyses.

I found no earthworms in the sandy soil over the course of the sampling period, strongly suggesting that no earthworms inhabit sandy soils. Sandy soils are too rough and painful for earthworms to crawl through, therefore they are actively avoided. The clay and loam soils had much higher numbers of individuals, with 9 species each. After statistical testing, it was concluded that there is no significant difference between the two soils and it could be said that they are similar in biodiversity. In addition, a strong correlation between particle density (how dense the soil is) and earthworm abundance was found. As particle density increases, to a certain extent, so does abundance.

Earthworm Sampling

To conclude, my data suggests that the clay and loam soils in the Morgan Arboretum are similar in biodiversity, both supporting an equally diverse number of earthworm species. However, the sandy soil does not contain any earthworms, suggesting that this type of soil is incapable of supporting earthworm activities. This is interesting information for soil management, since, in terms of earthworm abundance and biodiversity, clay and loam soils are similar.

Earthworms are essential ecosystem engineers that change the soil to better suit their lifestyle and this is why they are often studied. Hopefully my story has encouraged readers to respect earthworms a bit more; after all, they do much more than be an excellent fish bait!


[1]        Cameron, E. K., Zabrodski, M. W., Karst, J., & Bayne, E. M. (2012). Non-native earthworm influences on ectomycorrhizal colonization and growth of white spruce. Ecoscience, 19(1), 29-37.

[2]        Jouquet, P., Dauber, J., Lagerlöf, J., Lavelle, P., & Lepage, M. (2006). Soil invertebrates as ecosystem engineers: intended and accidental effects on soil and feedback loops. Applied Soil Ecology,  32(2), 153-164.