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This article advances geographic scholarship about conservation and protected areas (PAs) through a focuson biocultural geographies. Biocultural geographies derive from relationships between heterogenousIndigenous stewardship practices, biological diversity, and trans-scalar multidimensional social, political, andecological processes. The concept brings together insights from political ecology and biocultural conservationto address the interplay between environmental governance, cultural change, and biodiversity. We drawfrom collaborative, transdisciplinary research with Siona, Siekopai, and Cofan Indigenous communities inthe northern Ecuadorian Amazon, a site of global importance for its biodiversity and cultural heritage. Thisis also a region of rapid and extensive social-ecological change driven by expanding agricultural frontiers,intensifying extractive industries, and new infrastructure development for regional integration. It is from thiscontext that we call for a timely and critical conversation between human–environment geographers and thefield of biocultural conservation, two approaches that have reshaped thinking about PAs and the role ofIndigenous stewardship in an era of accelerating global challenges to social-ecological well-being. Data forour analysis derive from a multiyear study that investigates strategies used to ensure social-ecological well-being in the face of change. Our findings show that Siona, Siekopai, and Cofan stewardship sustains thebiological diversity that characterizes many Amazonian PAs through locally adapted institutions based onknowledge, innovation, and practices they collectively hold. Such stewardship advances self-determinationthat challenges conventional conservation and PA models by centering Indigenous territorial governance. 

The use of stone hammers to produce sharp stone flakes—knapping—is thought to represent a significant stage in hominin technological evolution because it facilitated the exploitation of novel resources, including meat obtained from medium‐to‐large‐sized vertebrates. The invention of knapping may have occurred via an additive (i.e., cumulative) process that combined several innovative stages. Here, we propose that one of these stages was the hominin use of ‘naturaliths,’ which we define as naturally produced sharp stone fragments that could be used as cutting tools. Based on a review of the literature and our own research, we first suggest that the ‘typical’ view, namely that sharp‐edged stones are seldom produced by nonprimate processes, is likely incorrect. Instead, naturaliths can be, and are being, endlessly produced in a wide range of settings and thus may occur on the landscape in far greater numbers than archaeologists currently understand or acknowledge. We then explore the potential role this ‘naturalith prevalence’ may have played in the origin of hominin stone knapping. Our hypothesis suggests that the origin of knapping was not a ‘Eureka!’ moment whereby hominins first made a sharp flake by intention or by accident and then sought something to cut, but instead was an emulative process by hominins aiming to reproduce the sharp tools furnished by mother nature and already in demand. We conclude with a discussion of several corollaries our proposal prompts, and several avenues of future research that can support or question our proposal. 

Conductometric titrations were used to measure sulfate concentrations in ground and surface water samples taken from land reclaimed after open-air coal mining. Sulfate concentrations ranged from 460 mg/L in surface water upstream of the former coal mine’s location to almost 3500 mg/L in groundwater sampled at the spoil site. Data from the titration measurements were benchmarked against EPA-approved ion chromatography (IC) measurements and results agreed to within ±3.6% (averaged over 36 samples) with a range of +10.4 and −11.3%. To test the generality of conductometric titration as a method for measuring dissolved constituents in environmental aquatic systems, additional measurements testing for chloride were performed with surface water samples collected from four different sites in south central and southwest Montana. Chloride concentrations ranged from 2.2 to 12 ppm. Based on measurements with control samples prepared in the laboratory, the environmental sample measurements are believed to be accurate to within ±6.4%. These conductometric titration studies highlight the technique’s simplicity, accuracy, cost effectiveness, and potential to produce rapid results. Additional analyses suggest that even simpler, non-species-specific conductivity data can provide an on-site, rapid assessment of sulfate levels in ground and surface water when historical speciation data are available. 

Linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and operando Raman spectroscopy were used to study the electrochemical performance and carbon tolerance of SOFCs operating with niobium doped SrTiO 3 (STN) anodes infiltrated with combinations of Ni, Co, and Ce 0.8 Gd 0.2 O 2 (CGO) added to improve catalytic activity. Cell anodes were exposed to fuel feeds of humidified H 2 , pure CH 4 and combinations of CO 2 and CH 4 at an operating temperature of 750 °C. Under pure CH 4 , Raman data show that carbon forms on all anodes containing Ni. In cells with CGO, deposited carbon results in a decreased polarization resistance. This behavior may be due to benefits conferred by CGO to the electrocatalytic activity of triple phase boundaries, presumably through improved oxide ion conductivity and/or due to carbon securing a better electrical connection in the electrodes. Raman spectra from Co-only containing anodes show no sign of carbon deposition. The absence of observable carbon together with low frequency processes observed in the EIS suggest that Co may play a role in oxidizing carbon before measurable amounts accumulate.