Suppose that you’re willing to assess how climate affects any ecological attribute of whatever habitat you’re interested with. For example, how algal habitats (as opposed to species or individuals) respond to increasing water temperatures. It’d be fantastic to have long-term data on the ecological attribute(s) and oceanographic data…but…uuuppppsss¡ no data, again. Can we figure out an alternative to respond our question? Well, a group of colleagues, including myself, believe latitudinal gradients in ocean temperature, at places where confounding by other co-varying factors is minimal, may represent an ideal chance. Inspiration for this idea in not new: biogeographers have long look into these issues.
Here, we have examined the relationship between several ocean temperature characteristics and habitat patch characteristics on 24 subtidal temperate reefs along a latitudinal gradient in Western Australia. We obtained a significant temperature-related variation in habitat structure, even though the total landscape cover of kelp and fucalean canopies did not change across the climate gradient: monospecific patches of kelp became increasingly dominant in warmer climates, at the expense of mixed kelp–fucalean canopies. These habitat changes were most closely related to patterns in minimum temperatures and hot temperature thresholds, presumably because temperate algae require cool periods for successful reproduction and recruitment (even if the adults can survive warmer temperatures).
For more info, see: T. Wernberg, Thomsen, M.S., Tuya, F., Kendrick, G.A. 2011. Biogenic habitat structure of seaweeds change along a latitudinal gradient in ocean temperature. Journal of Experimental Marine Biology and Ecology 400: 264-271.