The Effect of Shrubification on Collared Pikas in a Changing Arctic Ecosystem

https://ncipl.org/

https://ncipl.org/

It is often easy to ignore the effects of climate change when those effects don’t have a direct impact on your immediate surroundings. However, if you take a closer look at the more northern habitats, you will see how climate change is affecting both the local tundra ecosystems and the animals who call that area home. One such animal is the collared pika – a mammal that resembles a small bunny and is part of the same order as rabbits (Lagomorpha). The effect that climate change is having on this mammal is currently being studied by University of Alberta researchers David Hik and Scott Williamson.

David Hik’s research emphasizes plant-herbivore-climate interactions in northern alpine and tundra ecosystems, while Scott Williamson is involved in research on elevation dependent warming (4). Scott Williamson’s research contributions on elevation-dependent warming were published in the journal Nature Climate Change in April, 2015
https://www.nature.com/nclimate/journal/v5/n5/full/nclimate2563.html

https://www.petsmagazine.com.sg/daily-bites/others/629-pika-cute

https://www.petsmagazine.com.sg/daily-bites/others/629-pika-cute

The collared pika is a species of pika that lives in the more extreme northern climates. They have adapted to this colder climate through a combination of different behavoiurs. They burrow under thick snow packs in the winter, which allows them to survive these colder months since they don’t hibernate (2). Collared pikas also gather food in the summer months and store it in a separate pantry or “cache” over the winter (2). In the summer, they hide from predators and shield themselves from the heat in rock “talus” sites at the base of landslides (3).

The food that they gather and store, mostly consists of green grasses and the leaves of alpine meadow plants (2). However, a combination of lower temperatures and other global warming trends is negatively affecting their food supply and ability to shelter themselves from the cold in snow packs. This is a concern considering that their populations are already dropping by 90% over the winter months, as observed by David Hik (2).

Northern habitats are currently being affected by the global warming trend of “shrubification,” which is having an impact on the survival of collared pikas. Shrubification is the colloquial term that describes the process of shrub expansion into more northern areas and at higher altitudes. These shrubs are able to expand farther north due to factors such as lower temperatures, soil disturbances and herbivory (1). For example, reduced temperatures allow for enhanced soil nutrient uptake. Landscape and soil disturbances also contribute to increased shrub abundance and distribution. Grazing herbivores have an impact on shrub distribution by altering seed production and seedbed size, transport of seeds and soil fertilization (1).

https://www.theglobeandmail.com/news/national/growth-of-arctic-shrubs-may-accelerate-global-warming-study-finds/article25333574/

https://www.theglobeandmail.com/news/national/growth-of-arctic-shrubs-may-accelerate-global-warming-study-finds/article25333574/

This process of shrubification is causing the already endangered collared pika populations to dwindle further due to decreasing their food sources and reducing the snow pack cover.

The advancement and canopy thickening of shrubs is causing a reduction in albedo (or, sun reflectance off snow), which contributes to warmer temperatures. It also takes longer for the snow to melt under shrubs, which then covers the meadow plant seedlings for a longer time and delays the growing season (2).

In combination with this, the lower temperatures are also causing more rain and ice and less snow. This then leads to reduced snow pack thickness, and when the rain freezes, it covers any winter vegetation with an impenetrable shell of ice (2). Therefore, the collared pikas face many challenges in their alpine habitats.

https://www.nicolasdory.com/2011-the-year-in-pictures/

https://www.nicolasdory.com/2011-the-year-in-pictures/

To help these creatures, make sure that you are doing all that you can, such as driving less, recycling, drinking water from reusable bottles and reducing your overall energy consumption. These fluffly little bunny-like creatures will surely thank you!

References:

1. Myers-Smith, I. H., Forbes, B. C., Wilmking, M., & Hik, D. S. (2011, December 20). Shrub expansion in tundra ecosystems: Dynamics, impacts and research priorities. Environ. Res. Lett., 6. https://iopscience.iop.org/article/10.1088/1748-9326/6/4/045509/meta

2. Pratt, S. (2016, Spring). Swim or Sink. New Trail (University of Alberta Alumni Magazine), 16-28.

3. https://en.wikipedia.org/wiki/Collared_pika

4. https://www.ualberta.ca/science/about-us/contact-us/faculty-directory/david-hik

5. https://www.theglobeandmail.com/news/national/growth-of-arctic-shrubs-may-accelerate-global-warming-study-finds/article25333574/

6. https://www.ualberta.ca/news-and-events/newsarticles/2015/april/mountains-warming-faster-say-researchers

7. https://esseacourses.strategies.org/module.php?module_id=99

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Big Tree Trail on Meares Island

Tofino is known for its great surfing beaches and community, but there are also some fabulous places to hike. One such place is the Big Tree Trail located on Meares Island about half a kilometre across the water from Tofino. This trail features some of the largest and oldest Western red cedar trees in the world with widths up to 20 feet.

Photo by Jacquie Boivin

Boat taxi trip from Tofino to Meares Island

Meares island is a tribal park of the Tla-o-qui-aht First Nations and got its name in 1862 from George Henry Richards, captain of the HMS Hecate, in honor of John Meares. This island was blockaded to prevent logging by the MacMillan Bloedel company in 1984. As a result of this protest, the Big Tree trail was created with a board walk for the first 1.2 km of the trail. Continue reading

Cycads: Are we pushing them to the edge of extinction?

Encephalartos woodiiCycads are gymnosperms arising from an ancient lineage, and are considered to be the most primitive of the living seed-bearing plants (Norstog 1997, Jones 2002).  Certain aspects of their biology and life cycle, are combining with human activities to push them to the edge of extinction (Norstog 1997, Jones 2002, Terry 2008).

Cycads have been around for at least 250 million years (Raven 1999), but they have been rapidly declining in numbers in recent years.  The cycads belong to a large class of trees known as the gymnosperms, which are non-flowering seed-bearing plants with “naked seeds” in their ovules that are directly exposed to pollen grains (Norstog et al. 1997, Everett).  The gymnosperms are comprised of eight orders, with three extinct (Cordaitales, Bennettitales and Glossopteridales) and five still living (Gingkoales, Cycadales, Pinales, Taxales and Gnetales) (Jones 2002).  The nearest relatives are thought to be the long extinct Pteridospermales (seed ferns) (Norstog 1997). At first glance, they can appear similar in form to palms, and in fact, in America are sometimes called sago-palms (Everett 1968).  But, they are more closely related to ferns than to palms (Everett 1968).

Cycads flourished during the Mesozoic era (Snow 2007), reaching the peak of their evolution by the Jurassic (Norstog 1997).  There are now believed to be upwards of 300 species (Donaldson 2004, Terry 2008) with 10 subspecies in 11 genera (Jones 2002).
The following are biological factors that predispose cycads to extinction:  habitat degradation and fragmentation, obligate insect pollinators, large seed size, and a dioecious life cycle.

Habitat Degradation and Fragmentation:
The world distribution for cycads is mainly tropical, subtropical to warm temperate regions of both the Northern and Southern hemispheres, with the region of greatest diversity occurring in Central America (Jones, 2002).  They are also usually restricted to areas within roughly 30 degrees on either side of the equator (Norstog 1997), but can occur in a variety of habitats, such as moist rainforests, deciduous mesophyll and evergreen sclerophyll forests (Jones, 2002).

However, cycads are usually restricted to particular climates and soil types (Jones 2002).  For example, Zamia Montana, is a mist forest cycad restricted to mist forests in Columbia (Jones 2002).  Therefore, any degradation or fragmentation to these habitats is troublesome.  For example, habitat degradation can lead to an increase in genetic drift, inbreeding, and can negatively impact interactions with pollinators and dispersers (Lopez-Gallego 2010, Terry 2008).  This can be particularly problematic for rare species, such as Dioon sonorense from Sonora, Mexico, due to high genetic differentiation, low diversity and limited to no recruitment of juveniles (Gonzalez-Astorga 2009).

Insect Pollination and Seed Dispersal:
It was long thought that cycads were predominantly wind pollinated (Norstog 1997, Jones 2002), but recent studies have shown that they are almost exclusively insect pollinated (Jones 2002, Terry 2008).  It was also found that insect pollinators, such as beetles, weevils and thrips, are often involved in obligate mutualisms with their host cycads (Jones 2002, Terry 2008), and that these relationships are ancient, dating back more than 200 million years ago (Jones 2002).  However human activities, including the use of pesticides, overcollection, habitat degradation and fire are leading to the loss of these host-specific pollinators (Jones 2002, Terry 2008, IUCN 2003).

Cycads also have large seeds when compared to other gymnosperms, with the largest cycad seeds belonging to Macrozamia species (Jones 2002).  In these cases, faunal extinctions can signal the loss of important seed dispersal mechanisms, as in the case for Macrozamia lucida (Snow 2007).

Another paper looked at Macrozamia platyrhachis of Queensland, Australia (Terry 2008).  This species has a long juvenile stage of 5 to 20+ years, along with low seedling establishment and localized seed dispersal.  This is another reason why habitat destruction and disturbance is problematic, as it can take a long time to re-establish viable adult populations.

Dioecious Life Cycle:
Cycads are generally dioecious (Raven 1999, Jones 2002, Norstog 1997), meaning that both male and female plants have separate forms.  This is beneficial for genetic outcrossing (Norstog 1997), but has negative implications for conservation for various reasons.
In the dioecious life cycle, both male and female plants need to be within the same vicinity for genetic outcrossing to occur. Therefore, at least two separate dispersal events are required if establishment of a new colony is to be successful (Jones 2002).

The dioecious nature of cycads also makes them vulnerable to overcollection of one sex or another, which can lead to sex imbalances.  For example, in the case of Cycas beddomei, of the Eastern Ghats in India, over-collection of male cones for medicinal purposes is threatening this species (Jones 2002).

Human Issues Affecting Conservation:
The biological aspects described above, are combining with human activities to further drive cycads toward extinction.  Examples of human activities include commercialization of cycad products such as starch from stems and seeds, illegal poaching for the nursery trade, and traditional uses (such as medicinal and religious (Perez-Farrera 2006)).  Habitat fragmentation and disturbance is due to agriculture and fire, the construction of highways and dams, mining and other activities. (Jones 2002, Donaldson 2004, Perez Farrera 2006, Norstog 1997).

Solutions and Conservation Management Strategies:
Many efforts are being made to slow or stop the extinction of cycads.  These include networks and rescue schemes (such as “Operation Wildflower”) along with in situ and ex situ conservation strategies (Jones 2002, Whitelock 2002).

Other efforts include the creation and enforcement of local and international laws, such as CITES and IUCN red listing, which are designed to limit the import and export of rare and endangered cycads (Norstog 1997, Whitelock 2002, Jones 2002).  IUCN red listing and taxonomy efforts increase public awareness of vulnerable species, and help to prevent illegal trade (Donaldson, 2004).  Another important effort is educational programs for the general public and of indigenous peoples who do not know the value of the plants being destroyed (Whitelock 2002, Jones 2002).

In conclusion, cycads are beautiful, ancient plants that can offer public enjoyment and insight into an ancient era.  However, their biology and human activities are combining to make them extremely vulnerable to extinction.  Hopefully, with greater public awareness and recent conservation management strategies, cycads will be on earth for many more millennia to come.

References:

Books and Journals:

    1. Alvarez-Yepiz, J., Dovciak, M., Burquez, A. (2011). Persistence of a rare ancient cycad:  Effects of environment and demography. Biological Conservation, 144:  122-130
    2. Donaldson, J., (2004). Saving Ghosts? Concepts and Recommendations:  Chapter:  Saving Ghosts? The Implications of Taxonomic Uncertainty and Shifting Infrageneric Concepts in the Cycadales for Red Listing and Conservation Planning. In Osborne, T., Walters, R.,  Cycad classification:  concepts and recommendations. Cambridge, MA:  CABI Publishing.
    3. Everett, T.H. (1968). Living trees of the world. New York:  Doubleday & Company
    4. Gonzalez-Astorga, J., Vovides, A.P., Cabrera-Toledo, D., Nicolalde-Morejon, F. (2009). Diversity and genetic structure of the endangered cycad Dioon sonorense (Zamiaceae) from Sonora, Mexico:  Evolutionary and conservation implications. Biochemical Systematics and Ecology, 36: 891-899
    5. Jones, D.L. (2002). Cycads of the World:  Ancient Plants in Today’s Landscape. Washington D.C.: Smithsonian Institution Press.
    6. Lopez-Gallego, C., O’Neil, P. (2010). Life-history variation following habitat degradation associated with differing fine-scale spatial genetic structure in a rainforest cycad. Popul Ecol, 52: 191-201
    7. Norstog KJ, Nicholls T. (1997).  The Biology of the Cycads. Ithaca, New York: Cornell University Press.
    8. Perez-Farrera, M., Vovides, A.P., Bol.Soc.Bot.Mex. (2006) The commercial use of the threatened “Espadana” cycad (Dioon merolae, Zamiaceae) by a community of the central depression of Chiapas, Mexico, Bol.Soc.Bot.Mex.,78: 107-113
    9. Raven, P.H., Evert, R., Eichhorn, S.E. (1999) Biology of Plants, Sixth edition. Freeman, Worth.
    10. Snow, E.L., Walter, G.H. (2007). Large seeds, extinct vectors and contemporary ecology:  testing dispersal in a locally distributed cycad, Macrozamia lucida (Cycadales). Australian Journal of Botany, 55: 592-600
    11. Terry, I., Forster, P., Moore, C.J., Roemer, R.B., Machin, P.J. (2008). Demographics, pollination syndrome and conservation status of Macrozamia platyrhachis (Zamiaceae), a geographically restricted Queensland cycad. Australian Journal of Botany, 56: 321-332
    12. Whitelock, L.M., (2002). The Cycads. Portland, OR: Timber Press

Online Resource:

  1. “The Cycad Society, Inc.” www.cycad.org/conservation.htm (Publications section, February 2012). Publication:  IUCN News Release, (2003), Modern Lifestyle Threatens Oldest Seed Plants on Earth.
  2. picture credit: https://www.iucnredlist.org/apps/redlist/details/41881/0

Getting Started with Moodle – Posting #2

I now have a Moodle learning site set up through Ninehub.com and chose a site name:

https://jacbird.freewebclass.com

I chose a theme by clicking on Appearance → Themes → Theme Selector,

and a fully functional Moodle site was ready!

 

My next stop was browsing through the Moodle documentation for teachers, located here:

https://docs.moodle.org/en/Getting_started_for_teachers

You can also experiment on the Moodle demonstration site, which is wiped clean and restored back to normal every hour on the hour:  https://demo.moodle.org

I found that the next step was to Turn Editing On, and Add a New Course.  This takes you to the course settings page where you can define yourself as an administrator and name your course.

Jacbird Test Course

    • Click on the course name, and you will see the administrator settings at the left. Administration area_left
    • Click on the Settings link to edit the course settings, and use the top navigation bar to navigate back to the main course page. Top Navigation Bar

In order to add or alter course activities, you have to Turn Editing On which is a button located at the top right.  Then use the drop-down menus in the centre window to add a resource or activity:

  • Add an activity such as a Forum, Chat, Wiki, Glossary, or Survey
  • Add a resource such as a Text Page or Web Page