White Pine Monitoring

Great Basin bristlecone pine on a talus slope in Great Basin National Park overlooking the sagebrush steppe

NPS photo

Why We Care

While not all parks in the Mojave Desert Network have white pine species, Great Basin National Park (GRBA) contains over ten thousand acres of Great Basin bristlecone pine (Pinus longaeva) and limber pine (P. flexilis) forest (Cogan et al. 2012). White pines in North American forests face unprecedented health challenges, including native pests and pathogens, invasive species, and altered disturbance regimes. These threats are concerning enough that, as of December 2017, GRBA included Great Basin bristlecone pine as a Species of Management Concern for internal park management due to its vulnerability to climate change, white pine blister rust, and possible mountain pine beetle outbreaks. In MOJN’s most collaborative long-term monitoring effort, we are working closely with GRBA staff and other Inventory and Monitoring networks, particularly the Upper Columbia Basin Network, Sierra Nevada Network, and the Klamath Network, to monitor white pine communities in GRBA.

“White Pines” and their Natural History

There are many species of white pines (Family Pinaceae, Genus Pinus, Subgenus Strobus), also called the “five-needle pines” since their needles are in bundles of 5. Limber pine and Great Basin bristlecone pine are the only two white pine species occurring in GRBA, and they are the focus of this monitoring effort.

White pines are foundation species, meaning they create locally stable conditions that are required by many other species, and stabilize fundamental ecosystem processes. Limber pine occupies the broadest elevational distribution, from lower elevation sites to treeline, of all North American white pines and occurs in a wide range of environments. Great Basin bristlecone pine is a high-elevation, long-lived species. With some individuals greater than 5,000 years old, it is debated to be the oldest non-clonal species on earth! This longevity could be related to their powerful plant defense traits against pests (Bentz et al. 2017).

Threats

White pines in the Mojave Desert Network are mostly threatened by organisms that cause damage to foliage, stems, and trunks of the tree, and climate change. All western white pines are threatened by an invasive pathogen (Cronartium ribicola) that causes the disease white pine blister rust. Two native organisms, dwarf mistletoe (Aceuthobium americanum) and mountain pine beetle (Dendroctonus ponderosae), also threaten these trees. Mountain pine beetle attacks have been increasing in high-elevation white pines in recent years, including the Death Valley National Park Great Basin bristlecone and limber pines. When trees are stressed by hotter droughts, they become more susceptible to beetle damage. And warmer temperatures facilitate beetle activity at higher elevations.

Our monitoring documents the effects of these three organisms on GRBA white pines. Nationwide, impacts from these organisms, alongside climate change, have been crippling white pine populations. To date, white pine forests in Great Basin National Park do not show signs of white pine blister rust impacts, but starting in 2023, our field staff have documented mountain pine beetle damage in some trees. Information about change in white pine forests will help park managers work with partners within the region to plan for and address declines.

How We Monitor

MOJN is monitoring limber pine and Great Basin bristlecone pine to better understand the dynamics of forest ecosystems under modern perturbations in GRBA. The monitoring will add to a growing body of information on white pine blister rust spread and epidemiology within white pine forest communities in a variety of biophysical settings. Alongside the three other Inventory & Monitoring networks, this long-term research effort asks the following monitoring questions:

• Are white pine forests changing in structure and species composition?
• Are rates of tree mortality increasing, are rates of recruitment from the seedling class (<137 cm height) into the tree class (≥137 cm height) decreasing, and are there declines in seedling regeneration (<137 cm height; seedlings/m²)?
• Are the key disturbance species—white pine blister rust, mountain pine beetle, and dwarf mistletoe—increasing in incidence and severity?

Pine Monitoring occurs at

Great Basin National Park

Reports and Publications

Monitoring protocols describe why and how we collect, manage, analyze, and report monitoring data about the network's Vital Signs. Each protocol consists of a narrative and an associated set of standard operating procedures (SOPs). Monitoring reports, as they are developed, will summarize data and findings from our Vital Signs monitoring activities and will also be available here.

Monitoring Protocol and Procedures

Source: Data Store Collection 4468 (results presented are a subset). To search for additional information, visit the Data Store.

Briefs
Here you will find project overviews and recent findings as they are available.

Source: Data Store Collection 7919. To search for additional information, visit the Data Store.

Literature Cited

Bentz, B. J., S. M. Hood, E. M. Hansen, J. C. Vandygriff, and K. E. Mock. 2017. Defense traits in the long‐lived Great Basin bristlecone pine and resistance to the native herbivore mountain pine beetle. New Phytologist 213(2):611-624.

Cogan, D, J. E. Taylor, and K. Schulz. 2012. Vegetation inventory project: Great Basin National Park. Natural Resource Report NPS/MOJN/NRR— 2012/568. National Park Service, Fort Collins, Colorado.