**Spoiler: While I personally lead maintain tons of admiration to those who exit academia afterwards Master/PhD graduation, this postal service is dedicated to those early-career researchers who remain too go along along the bittersweet journeying called academia **
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Fig.1: Achnanthes submarina Hustedt, a dominant diatom species of the Ebro Delta habitats. Photo yesteryear X. Benito |
South American diatom biodiversity
The biodiversity of the South American continent was crucial for Charles Darwin's Origin of Species seminal theory that populations evolve over the course of educational activity of generations through a procedure of natural selection. During his travel, Darwin recognized the importance of biogeography too history too how these 2 factors operate together to shape life on Earth. While inwards South America, Darwin learned about Professor Christian Ehrenberg's microscopic observations of diatoms. Due to the sometime historic menses of these diatom-rich geological deposits called diatomites, based on his novel theory, Darwin thought that the diatoms should last sometime too lead maintain a broad geographical distribution. Maybe without straight proverb it, the start observations of South American diatoms yesteryear Darwin too Ehrenberg dorsum inwards the 19th century, were strongly related to historical biogeography, which is present a hot theme inwards microbial biogeography discussions. That is, due to the massive dispersal capacity too large populations of microorganisms, including diatoms, cosmopolitan (existing worldwide) distribution patterns should prevail over restricted, endemic (typical for 1 region) distribution patterns. In other words, everything is everywhere too the surround makes the selection, besides known equally the Baas-Becking hypothesis [1]. This framework was the heart motivation of my next research, which built upon questions of diatom dispersal too long-term too regional perspectives of environmental change. |
| Fig. 2: Lake Chiriacu, Ecuadorean Andes. Photo yesteryear X. Benito |
In the tropical Andes, some authors lead maintain challenged the thought that diatoms are cosmopolitan, contestation that a higher let out of endemisms should be than those currently known [2]. One of the most comprehensive diatom floras identified 888 diatom taxa from 350 samples randomly distributed from Venezuela to Argentine Republic along the Andes [3], spell some other written report establish 228 taxa inwards a unmarried sample from an Andean Bolivian current (with many taxa non identified at the species level) [2]. Furthermore, yesteryear analyzing a diatom metadatabase from the tropical Andes too side yesteryear side lowlands, my colleagues too I establish a full of 1,086 taxa inwards 163 aquatic samples, including streams too lakes, too estimated the articulation contribution of local environmental variables (water chemistry) too dispersal dynamics (spatial factors such equally aquatic connectivity) inwards affecting diatom community composition [4]. These recent studies present how biologically various too complex Andean aquatic environments are, too how a non bad component subdivision of the diatom works seems nevertheless to last discovered.
My lead maintain on diatom diversity
Because diatoms are 1 of the most of import components at the base of operations of the nutrient chain inwards aquatic environments, I was curious whether diatoms could last used to investigate potential human-environment impacts. I recognize that ecological problems are besides social problems. For instance, human-induced climate modify threatens to jeopardize many of the world's ecosystems services (benefits that nature provides to human societies such equally H2O provision from lakes, agricultural resources from land, or coastal protection from storms). In my electrical current postdoctoral companionship at the National Socio-Environmental Synthesis Center (SESYNC), I written report coupled long-term human-environment systems using tropical Andean lakes equally model systems. Despite the apparent pristine atmospheric condition of Andean lakes (Fig. 2), humans lead maintain shaped a dynamic cultural landscape next the Inca empire expansion (AD 1450) too Castilian colonization (AD 1542). Currently, population increment too poverty equally good equally damming, cattle grazing too fish stocking threaten lake too páramo grassland ecosystems that inwards plough furnish H2O resources to rural too urban communities. However, agreement such complex socio-ecological systems inwards the high-altitude tropical Andes is challenging due to the lack of long-term consistent information sets. This cognition gap may last limiting our agreement of the impending impacts of human-induced climate modify inwards mount communities [5].Ongoing operate & outlook
Diatoms lead maintain been ever at the heart of my inquiry too inspiration to continuously seek novel approaches too ideas that volition ultimately help people too nature. With a grouping of colleagues too collaborators, I am analyzing a unique combination of diatom community data, biophysical information (pollen too sediment geochemistry), too human information (archaeological records) to empathise the nature too trajectories of human-environment couplings inwards the tropical Andes over time. Our preliminary results demonstrate a concomitant modify occurred unopen to 2000 years agone inwards iii dissimilar Andean lakes of varied size too chemistries, which may allow bespeak whether early-warning signals precede these synchronous transitions.Studies that address questions on adaptive dynamics, resilience for people too ecosystems may last to a greater extent than useful than studies using static, neo-ecological approaches (e.g. short-term studies) [6]. Thus, I volition investigate how historical too palaeoecological perspectives of resilience tin sack furnish an choice agreement to the monitoring-oriented approach inwards these socio-economic valuable ecosystems, which furnish multiple goods for much of Andean too Amazonian nations.
by Xavier Benito, PhD
Postdoctoral immature adult man at the National Socio-Environment Synthesis Center (SESYNC)
If y'all lead maintain questions or comments concerning Xavier's post, delight exit a comment below. You tin sack also visit his website or connect amongst him on Twitter.
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References:
[1] Williams, D.M. (2011) Historical biogeography, microbial endemism too the role of classification: everything is endemic. In Fontaneto, D. (ed) Biogeography of Microscopic Organisms. Is Everything Small Everywhere? Cambridge University Press, Cambridge.
[2] Morales, E.A., Novais, M.H., Chávez, G., Hoffmann, L. & Ector, L. (2012) Diatoms (Bacillariophyceae) from the Bolivian Altiplano: Three novel araphid species from the Desaguadero River draining Lake Titicaca. Fottea, 12, 41–58.
[3] Rumrich, U., Lange-Bertalot, H. & Rumrich, M. (2000) Diatoms of the Andes, from Venezuela to Patagonia/Tierra Del Fuego, too Two Additional Contributions. Iconographia diatomologica nine ARG Gartner Verlag KG, Königstein.
[4] Benito, X., Fritz, S.C., Steinitz-Kannan, M., Tapia, P., Kelly, M.A. & Lowell, T.V. (2018) Geo-climatic factors drive diatom community distribution inwards tropical South American freshwaters. Journal of Ecology, 106, 1660–1672
[5] Wymann von Dach, S., Bracher, C., Peralvo, M., Perez, K., Adler, C., et al. 2018. Leaving no 1 inwards mountains behind: Localizing the SDGs for resilience of mount people too ecosystems. Issue Brief on Sustainable Mountain Development. Bern, Switzerland: Centre for Development too Environment too Mountain Research Initiative, amongst Bern Open Publishing (BOP).
[6] Knapp, Gregory. 1991. Andean Ecology: Adaptive Dynamics inwards Ecuador. Westview Press