Researchers at La Brea Tar Pits have discovered a previously unknown juniper species, Juniperus scopulorum (Rocky Mountain juniper), through fossilized seeds, providing insights into historical climate changes and the impact of modern climate stressors on juniper populations. This finding reveals the interplay between two juniper species, highlighting their adaptations during periods of drought and how they have shaped the ecosystem in Southern California over thousands of years. The study, published in “New Phytologist,” emphasizes the role of junipers as keystone species that defined the region’s landscape and supported Ice Age megafauna like mammoths.
By radiocarbon dating fossil junipers, scientists observed patterns of reciprocal presence between the drought-tolerant California juniper and Rocky Mountain juniper, correlating these shifts with historical periods of aridity and climate fluctuations. The small size of the fossil seeds presented challenges for identification, necessitating advanced microscopy and analytical techniques. The extinction of Rocky Mountain juniper may have been influenced by climate change, human-caused fires, and loss of habitat, underscoring the ongoing threats faced by junipers today. This research aids conservation efforts by contextualizing past climate events to understand current environmental challenges.
