Last year, I wrote about how the warnings about human-accelerated climate change we’ve been hearing (and those of us in the business have been sending) for decades are, unfortunately, coming true. Almost daily, our news feeds remind us of this, or provide new evidence that Earth’s climate, and the environmental systems affected by it, are approaching unknown territory. We are seeing ocean temperatures, ice loss from the great Antarctic and Greenland ice sheets, storm and flood regimes, heat waves, and fires that are unprecedented in human history and in some cases unprecedented in Earth history, period. 

National Weather Service heat warnings for California

As much as we’d like to think otherwise, the facts (data, analyses, results, observations) do not speak for themselves. As scientists and educators, we are obliged to explain and interpret the facts; to attach meaning to them. As things have come to pass in the scientific world, we are obliged to speak for the facts in English. 

This post was inspired by a discussion posted on researchgate.net by Alejandro Bortolus of the Centro Nacional Patagonico (Argentina): Is the use of English in scientific articles a real need for an international working language, or a sign of long-lasting Colonialism? The lively discussion can be accessed here.

You can’t rely on me for a comprehensive and coherent summary of the comments and reactions, but some key themes are:

•The (obvious) advantages of having a single lingua franca to support global scientific communication. 

Spoiler alert--the answer is: maybe, but I’m not sure.

Argillic horizons are subsoil layers that are enriched in silicate clays. I have long been interested in soil morphology as it relates to argillic horizons. First, it was with respect to soil erosion. As these horizons are by definition formed below the surface, their exposure at or near the ground surface indicates removal of overlying soil. To the extent soils have a characteristic depth, or range of depths, to the top of the argillic horizon, then variations in DTA (depth to argillic) can indicate erosion or deposition. I used this to study soil erosion in the North Carolina coastal plain and piedmont in the late 1980s and 1990s, and in the Ouachita Mountains of Arkansas in the 2000s and 2010s.

Multiple argillic horizons in a Kandiustult in Zambia (source: https://www.uidaho.edu/cals/soil-orders/ultisols).

Some incomplete thoughts and notes on Earth surface system (ESS) evolutionary pathways, focusing on how to think about the enormous variety and large number of possibilities.

ESS encompasses geomorphic and soil landscapes, hydrological systems, and ecosystems. There exists a huge variety of them on our planet. Assuming we could ever inventory or even estimate them all, we can define N_ESS  as the number of ESS. For each of these multiple possible evolutionary pathways exist. So we define

N_i(p) = number of possible evolutionary pathways for each of i = 1, 2, . . . , N_ESS.

Image credit: Turbosquid.com

At any given point in history there were multiple potential evolutionary possibilities, such that N_global(p) = number of total possible pathways = Σ N_i(p). However, only one history has occurred for each individual ESS, so that the number of actual past pathways now manifest = N_ESS.

In ecological systems, structural redundancy refers to the extent to which more than one species (or taxanomic group) can perform a given function or play a given role in the system. Microbial communities or ecosystems, for instance, tend to have high structural redundancy at the species level, as there usually exists multiple bacteria or other microbes that can, say, break down specific forms of organic matter, reduce iron, precipitate calcium, or what have you. Systems with a single keystone species have low redundancy, at least with respect to whatever the keystone organism does (if something else could perform the same function, then it would not be a keystone). Redundancy tends to be inversely correlated to the degree of biotic specialization, and directly related to ecosystem resilience.