By Stacie Evans – Science Director at Takshanuk Watershed Council
Biodiversity loss is a hot topic these days, often sharing space with climate change in the news. Pithy headlines paint a depressing picture as more species go extinct each day, but many are left to wonder why this really matters. Aren’t there worse things to worry about? Unfortunately, not really. It turns out that humanity needs many different species, from invisible microbes to flocks of birds, to keep our air breathable, our water drinkable, and to grow food for an ever increasing population. In addition, Indigenous Knowledge tells us that biodiversity is essential for our overall wellbeing and mental health (a point that was recently corroborated with Western Science methodology).
Fortunately, some places appear to be somewhat resilient to this trend. Forgive the circular logic, but the best way for an ecosystem to remain biodiverse is to be… well biodiverse. Perhaps it is helpful to envision an ecosystem as a web. The more strands (species) that are woven into the web, the stronger it is. If you throw something at a web made of only a few strands, the whole thing will collapse. If you throw the same object at a web made of many strands, a few strands may break, but the web still functions.
In other words, an ecosystem with low biodiversity is vulnerable to threats like climate change because it can’t withstand the loss of a few species. On the other hand, as some species go extinct in an ecosystem with high biodiversity, others may be able to fill the niche and continue to perform the necessary functions.
When thinking of biodiversity, people are probably more likely to envision a steamy jungle teaming with life, than just about anywhere in Alaska. As a general rule of thumb, the closer the ecosystem is to the equator, the higher its biodiversity; however, as with most things in nature, this rule doesn’t apply equally across the board. For example, a place can experience high biodiversity relative to its latitude. The Chilkat Valley just so happens to be one of those places.
Although situated at a relatively northern latitude, the Chilkat Valley enjoys a spectacular array of local species. In fact, this place boasts the most vascular plant and mammal species found in Alaska, as well as the highest number of breeding bird species detected in Alaska during USGS’s annual breeding bird surveys.
These phenomena can be attributed to the multiple dramatic ecotones at play here. In other words, the Chilkat Valley is located at the nexus of several different types of ecosystems that overlap. Estuaries are a good example of this, with freshwater and saltwater habitats blending to create a zone that is suitable for species from both habitats. Another example is the low lying mountain passes that allow species to easily travel between the higher and dryer habitat of the interior, and the lower and damper habitat of the coast.
One notable species that seems to have found refuge in the ecotone between coastal and interior habitats, is the Canada lynx (lynx canadensis). Lynx are uncommon in coastal regions, so after an influx was observed in 2019 and 2020, curious local researchers and volunteers formed a group dedicated to learning more about lynx populations in the Chilkat Valley. This group, headed by lynx specialist Liz Hofer, launched the Chilkat Valley Lynx Project, which aims to use camera trapping, tracking, fur/skin sampling for diet analysis, and eventually tissue sampling for genetic analysis to discover how, why, and to what extent lynx are finding refuge in the Chilkat Valley.
The project is still in its early stages, and lynx populations, which are cyclical, are currently low, however, images retrieved from remote cameras reveal some pretty stunning examples biodiversity and abundance. Aside from many thousands of pictures of bears, moose, and squirrels, these cameras have also captured wolverines, marten, river otters, beavers, wolves, coyotes, snowshoe hares, porcupines, deer, grouse, bald eagles, multiple other bird species, and even flying squirrels.
Due to this biodiversity, special places like the Chilkat Valley have built in resiliency to ecological threats. Such places will become increasingly valuable each day as species loss occurs across the globe, and it will become increasingly important to protect them. Fortunately, the Chilkat Valley is filled with residents who take pride in the stability it has to offer on this rapidly changing planet. Thanks for caring and thanks for reading.
Watershed weekly is a semi-regular column sponsored by Takshanuk Watershed Council.