Shaking things up

It is common to describe our existing ecosystems like finished jigsaw puzzles; every piece, while different in size and shape, fits together snuggly to make the bigger picture work. It would be nice if range shifts due to climate change would just move the whole puzzle somewhere else. If you could just roll up everything in a puzzle mat and put it somewhere safer.  But range shifts are more akin to little brothers who come in and scatter the pieces of your puzzle. They bend pieces so they no longer fit and put pieces in wrong boxes.  You can call it ecological disassociation or community disintegration or whatever you like, but after the sorting is done and you try to shove all the new pieces together the picture will never be the same.

Analysis of the fossil record during the Pleistocene13 and the Holocene7 show just the sort of chaos a younger sibling would cause on a puzzle collection.  Species move at different times, at different speeds and even in different directions, and what was, never reassembles. Trends mean very little for trying to predict where a species will end up as there is more varied responses to climate change within closely related species then from between broader taxonomic groups.3

Spiders fighting

One experiment involving warming of grasslands in New England saw an overlap in the ranges of two spider species, due to shifts from one species, which resulted in intraguild predation, where one species hunts the other until a loser is eradicated from the area.  The resultant loss of spider diversity changed pest populations, which then changed the productivity of primary producers, which hurt herbivores and finally impacted larger carnivores.19  The cascade of trophic disruption seen in this study came as the result of one shift, one puzzle piece being rearranged.  

Competition and intraguild predation pose a real risk for both the Canadian Lynx and the bobcat.  Both cats live sympatrically with cougars, wolves, red foxes, and coyotes.  In most areas these species pursue different prey, but if a principal prey item for one of these predators were to leave an environment, the need to push in on another group’s food source would be great. 
    
One of the biggest threats to the Lynx may actually be the bobcat. With the shortening of winters in the southern parts of the lynx’s habitat, the smaller more aggressive bobcat is slowly pushing the Lynx out.  There seems to be more evidence of hybridization then intraguild predation in these instances, but without the advantage of deep snow to ensure a competitive edge, the Lynx populations are yielding ground.  

Bobcat in snow

Cat Photo by Plasticrevolver Via Tumblr
Spider Photo by BarneyF via Publicnow.com 
Bobcat Photo from stock photos