Sierra Nevada Network high elevation white pine monitoring: 2019 annual report

Nesmith, Jonathan

Five-needle white pines (Family Pinaceae, Genus Pinus, Subgenus Strobus), and in particular whitebark pine (Pinus albicaulis), limber pine (P. flexilis), and foxtail pine (P. balfouriana) are foundation species in upper subalpine and treeline forests of several National Park Service Pacific West Region parks, including Sequoia and Kings Canyon National Parks (SEKI) and Yosemite National Park (YOSE). The Sierra Nevada Network Inventory & Monitoring Program, in collaboration with the Klamath Network, Upper Columbia Basin Network, and Mojave Desert Network have implemented a joint long-term monitoring protocol to assess the current status and future trends in high elevation white pine communities. Key demographic parameters within white pine forest communities will be estimated by monitoring individual trees within permanent plots through time. This report documents the results of the 2019 field season, which was the seventh year of monitoring in SEKI and YOSE. The 2019 goal was to complete the first full re-measure of the first of three rotating panels (Panel 1) for each species-park population: YOSE-whitebark pine, SEKI-whitebark pine, and SEKI-foxtail pine. Each panel consists of 12 permanent 50 x 50 m (2,500 m2) plots that were randomly selected for each of the three populations. The full sampling array thus includes a total of 36 whitebark pine plots in YOSE, 36 whitebark pine plots in SEKI, and 36 foxtail pine plots in SEKI. Data from plot surveys will be used to characterize white pine forest community dynamics in SEKI and YOSE, including changes in tree species composition, forest structure, forest health, and demographics. A partial re-measure of Panel 1 was completed in 2015. In 2019, the remaining three Panel 1 plots that had not been installed in 2011 or 2015 were completed, finishing the installation of all Panel 1 plots. In addition, 2019 was the first year of data collection for a separate pilot project to monitor giant sequoias in SEKI and YOSE. The results of that project are not included in this report. In total, the crew visited 36 sites during the 2019 field season. One of these plots was from Panel 2 and was re-read and uninstalled due to safety concerns and another was a Panel 3 site in SEKI that was tagged, but not measured. Two of the Panel 1 plots were not visited due to time constraints imposed on the field season by the high snowpack. Within the 34 completed Panel 1 plots, a total of 4,894 trees were measured. Species composition, forest structure, and factors affecting tree health and reproduction including incidence and severity of white pine blister rust (Cronartium ribicola) infection, mountain pine beetle (Dendroctonus ponderosae) infestation, dwarf mistletoe (Arceuthobium spp.) infection, canopy kill, and female cone production were recorded. During the 2019 field season crews not only noted the presence or absence of female cones, but also counted the total number of mature cones per tree for whitebark and foxtail pine. In addition, individual seedlings were tagged instead of just being counted by size class and will be tracked through time. In 2019 the crew also continued the use of crown condition codes to assess crown health. All three of these procedures started in 2017 and were conducted by each of the three participating networks and will be evaluated over the next few years to determine whether they should become permanent changes to the monitoring protocol. In YOSE, 11 of 12 Panel 1 whitebark pine plots were re-measured. A total of 2,432 trees were sampled, which included 1,803 live whitebark pine trees and 584 other live conifers. An additional 45 trees (including 14 whitebark) were recorded as dead. White pine blister rust (WPBR) aecia were observed on four whitebark pine in four plots in YOSE in 2019, with an additional two trees showing three or more indicators of WPBR. This is the largest increase in number of plots where WPBR has been observed in YOSE to date, as it had...

Sierra Nevada Network high elevation white pine monitoring: 2019 annual report

Series