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In the catchments of the Rocky Mountains, peak snowpack is declining in response to warmer spring temperatures. To understand how this will influence terrestrial gross primary production (GPP), we compared precipitation data across the intermountain west with satellite retrievals of solar‐induced fluorescence (SIF), a proxy for GPP. Annual precipitation patterns explained most of the spatial and temporal variability of SIF, but the slope of the response was dependent on site to site differences in the proportion of snowpack to summer rain. We separated the response of SIF to different seasonal precipitation amounts and found that SIF was approximately twice as sensitive to variations in summer rain than snowpack. The response of peak GPP to a secular decline in snowpack will likely be subtle, whereas a change in summer rain amount will have precipitous effects on GPP. The study suggests that the rain use efficiency of Rocky Mountain ecosystems is strongly dependent on precipitation form and timing.

High-elevation environments above 2500 metres above sea level (m.a.s.l.) were among the planet's last frontiers of human colonization. Research on the speed and tempo of this colonization process is active and holds implications for understanding rates of genetic, physiological and cultural adaptation in our species. Permanent occupation of high-elevation environments in the Andes Mountains of South America tentatively began with hunter–gatherers around 9 ka according to current archaeological estimates, though the timing is currently debated. Recent observations on the archaeological site of Soro Mik'aya Patjxa (8.0–6.5 ka), located at 3800 m.a.s.l. in the Andean Altiplano, offer an opportunity to independently test hypotheses for early permanent use of the region. This study observes low oxygen (δ18O) and high carbon (δ13C) isotope values in human bone, long travel distances to low-elevation zones, variable age and sex structure in the human population and an absence of non-local lithic materials. These independent lines of evidence converge to support a model of permanent occupation of high elevations and refute logistical and seasonal use models. The results constitute the strongest empirical support to date for permanent human occupation of the Andean highlands by hunter–gatherers before 7 ka.

The historical development of gender diversity in paleontology may be representative of similar changes across the geosciences. An analysis of the programs of the ten North American Paleontological Conventions held since 1969 shows a steady increase in the participation by women in the discipline. Notably, the proportion of male authorship on abstracts was stable while female authorship contribution increased. Much of the growth in female authorship is due to increased collaboration and recognition of student participation with junior authorship. These changes are just starting to be reflected at more senior levels; strategies need to be implemented to ensure that young female geoscientists are retained and developed.Studies of long-term trends in gender dynamics in science can help identify strategies that are working and highlight additional actions to further reduce barriers to full participation. We examined such long-term changes in meeting participation in paleontology. By examining meeting participation, rather than employment trends (e.g., Holmes and O'Connell 2003), we investigate gender dynamics within the intellectual development of a discipline.Paleontology is a diverse field, and workers in the various subdisciplines often attend different conferences. Every four to five years, however, all flavors of paleontologist converge for the North American Paleontological Convention (NAPC). The first of these was held in 1969 (Yochelson, 1996); the tenth and most recent this past February. The programs of these meetings reflect transformations in how, and by whom, the science of paleontology is practiced.The first NAPC was limited to 79 presentations in organized symposia. Nearly all of the presentations were single-authored, and only two talks were presented by women. In contrast, the 2014 meeting included 315 separate talks, many in posters and contributed sessions. Most were multi-authored, and 130 of the presenters were women, a two order of magnitude increase in female participation since 1969.There clearly have been some fundamental changes in the nature of paleontological conferences and, by implication, the field of paleontology. To track how these changes occurred over time, we analyzed the program and abstract volumes for all ten GSA Today, v. 24, no. 11, NAPCs. For each, we counted the total number of abstracts; the number of authors per abstract; whether an abstract had at least one female or male author and if so, how many; and whether a woman was the senior or sole author. Gender was determined either by first name or by personal knowledge of the author in ambiguous cases. To measure how many times an author appeared on multiple abstracts, we divided the total number of authors on abstracts by the number of unique names of authors (multiple authorship index). We standardized the data by dividing each value by the number of published abstracts. When possible, we recorded whether a woman chaired or co-chaired a session and whether a woman was a keynote or plenary session presenter; this data was i...

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) in lake sediments are increasingly being used to reconstruct past temperatures. However, recent studies suggest that brGDGT distributions and concentrations vary with lake size and environmental conditions such as seasonality and its effects on water column temperature and chemistry. To test their use as a paleothermometer in high-altitude environments of mid-latitude North America, we analyzed brGDGT distributions in lake surface sediments across a range of lake depths and elevations in the Rocky Mountains of Wyoming and Colorado. Our results suggest that brGDGT distributions and the MBT'5Me index correlate with water column temperatures, which are sensitive to both lake water depth and air temperatures. Based on these relationships, we developed a calibration to mean summer air temperatures using a Bayesian regression model that incorporates the MBT' 5Me index and lake water depth. We applied our calibration to lake sediments from Lower Paintrock Lake in northern Wyoming to test its use as a paleothermometer. Reconstructed temperature trends are consistent with pollen-inferred temperatures at the same site and with known regional climate history, demonstrating that our calibration can be successfully applied to infer temperatures in high-altitude environments of midlatitude North America.

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