Junipers, The Tree That Ate The West:
In the Pacific Northwest, the Western Juniper (Juniperus occindentalus) is found in arid country east of the Cascades, its short, conical form dotting hillsides and mesas from Chelan to the Owyhee. Western Juniper is particularly common in high desert of central Oregon, where some long-lived individuals have stood for over 1500 years, attaining great girth and a sort of gnarled grace. Yet paradoxically, its modern extent is a recent phenomenon, and has come at a severe cost to the high desert ecosystem, where it now effectively functions as an invasive species—albeit a home-grown one. This is because prior to European colonization, junipers were primarily restricted to rocky alcoves with shallow soil and limited moisture, sheltered from frequent wildfire. Following the introduction of cattle in the 1870s, however, the combined effect of grazing pressure on fire-prone native grass and active fire suppression efforts by settlers severely reduced the frequency of rangeland burns. Junipers were thus able to establish in places they had previously been restricted from, rapidly outcompeting sagebrush, cheatgrass, and other native plants. The California Academy of Sciences’ Biographic series has a rundown of this history and its cascading effects, which poses difficult questions about our relationship with the living world. How do we determine whether something is “natural,” and does the concept itself have any value? How do we balance competing instincts to let wild landscapes operate according to their own principles with interventionist approaches to preserve things as they were?
Ranking Climate Change On the List of Conservation Priorities: ...Though important, these questions are themselves often overshadowed by another, more pressing one: in the the face of the existential threat posed by climate change, how much should we worry about the implications of other human-caused environmental damage? A recent comment in the journal Nature suggests the answer is that we should worry quite a bit. In a similar manner to how the CDC ranks the major causes of human death, the authors sought to quantify the leading drivers of biodiversity loss. Their findings suggest the many effects of climate change are currently far down the list, affecting less than 20% of the species they studied. Instead, three-quarters of their focal species were primarily threatened by the conversion of habitat to agricultural land, logging, and overhunting. Of course, as The New Yorker’s Michelle Nijhuis points out, this is no excuse for climate complacency: “While the harms that climate change does to biodiversity—and humanity—lie mostly in the future, and their specifics remain uncertain, their significance is beyond doubt”
On Academics And Social Media: My hunch is that there are very few young scientists who think academics should be more insular than they already are, but the Guardian managed to find one, who published an editorial in the newspaper railing against social media use in the Ivory Tower late last week. “Surely the dedication I show in the lab, and the subsequent data I collect, should speak for itself. I do not–and should not–have to parade myself online to please my employer or to stake my claim as a good researcher,” the anonymous author states. By and large, it hasn’t gone over well: as Small Pond Science’s Terry McGlenn explains, the editorial’s premise rests on the straw argument that academics are sharing their work with the public to please employers. He counters that “[as] an academic, interacting with the public is my job, and social media allows me to do this more and better.”
Geologic Evidence for a Mythic Chinese Flood: According to Chinese tradition, Emperor Yu the Great managed to tame a devastating flood along the Yellow River through dredging, a triumph that signaled the start of the Xia Dynasty and thus the beginning of all Chinese civilization. Over the past century, historians and archaeologists have treated the story with different levels of skepticism, ranging from taking textual accounts of the event more or less verbatim to dismissing it entirely. Now, in an article published in the journal Science this month, Qinglong Wu and colleagues present geologic evidence in support of this myth, including deposits reaching over 240m above the current riverbanks and outburst flood sediments downstream. Taken together, the team suggests these data paint a picture of a six-nine month flood event around 1920 BCE, caused by earthquake-triggered landslides that dammed the Yellow River.