Treesearch

The structural and functional attributes of urban and peri-urban forests are the basis for the provision of a suite of ecosystem services that directly and indirectly benefit residents across scales, tenures and land uses. As such, many local governments promote municipal urban forest initiatives such as maintenance and management plans, ordinances, and tree-giveaway programs (e.g. Orlando, USA and Sydney, Australia). However, the effectiveness and distributional fairness of these activities often overlooks residents’ values and preferences for certain tree functional traits, sizes,...

To determine the effect of nursery lifting dates on field performance of containerized Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings, we lifted and stored seedlings from 2 seed lots on 9 dates from late October 2019 to early March 2020. We planted the seedlings in a field test and in large pots in April 2020. All seedlings broke bud and grew vigorously. No mortality occurred in the pots, and less than 6 percent mortality occurred in the field test. Bud burst was slightly faster for seedlings lifted after mid-January than for those lifted on earlier dates. We found consistent...

Orasema minutissima Howard (Hymenoptera: Eucharitidae) is recorded from the Hawaiian Islands for the first time. It has been established on the island of Hawai‘i since at least 2019. The wasp is a parasitoid of the immature stages of Pheidole and Wasmannia (Formicidae: Myrmicinae), both of which are significant pests on several of the Hawaiian Islands. Already found in substantial numbers, the wasp is a potential biological control agent for Wasmannia auropunctata, the Little Fire Ant.

This chapter considers social vulnerability to climate change by assessing the effects of climate change on outdoor recreation in the Sierra Nevada bioregion (Fischer et al. 2013) (fig. 5.1), and providing the information needed to manage for risk and to minimize loss (Aplet et al. 2010). By considering current and projected effects, we hope to better equip land managers and stakeholders with information that can aid management and planning for socioecological resilience. The report expands the emphasis on recreation provided in a recent science synthesis for the Sierra Nevada (Long et al....

Climate change is currently affecting ecosystems and natural resources in forest ecosystems across the Western United States (Dettinger et al. 2018, Halofsky and Peterson 2017, Wuebbles et al. 2017). To prepare for the effects of increasing temperatures and shifts in precipitation, resource managers working for the U.S. Department of Agriculture, Forest Service (USFS) are currently mandated to integrate climate change information into decisionmaking during land management planning (USDA FS 2012). Climate change adaptation, or taking actions to reduce risks from changing climatic conditions...

The Sierra Nevada Infrastructure and Recreation Vulnerability Assessment and Adaptation Partnership (hereafter Sierra Nevada Partnership) contributed to our understanding of climate change vulnerabilities and responses to potential climate change effects in national forests in the Sierra Nevada (Modoc National Forest [NF], Lassen NF, Plumas NF, Tahoe NF, Lake Tahoe Basin Management Unit, Eldorado NF, Stanislaus NF, Sierra NF, Inyo NF, Sequoia NF). The effort synthesized the best available scientific information to assess climate change vulnerability for recreation and infrastructure,...

The Sierra Nevada region is characterized by high topographical and climatological diversity (Dettinger et al. 2018), extending 400 mi north to south and 70 mi east to west. Elevations are higher in the southern end of the range, with Mount Whitney (14,505 ft) being the highest peak in the contiguous United States; peaks in the northern part of the range are generally less than 8,800 ft (Minnich and Padgett 2003). The western portion of the Sierra Nevada region is characterized by a Mediterranean climate, with cool, wet winters and warm, dry summers. The western portion of the Sierra...

The Sierra Nevada contains 24 major river basins that provide water to downstream ecosystems and human communities. Water resources and ecosystem services are derived from snowpacks accumulated at high elevations, replenishing soil moisture through snowmelt and generating streamflow during the spring and early summer. Streamflows produced from Sierra Nevada snowpack account for about 30 percent of California’s total water supply, provide about 60 percent of water consumed by the state’s population, and generate nearly half of the state’s hydroelectric power (Bales et al. 2011a, Dettinger...

The Sierra Nevada is a biologically diverse and socially important region of California, providing water, timber, rangeland, recreation, and many other ecosystem services. A significant amount of infrastructure (roads, bridges, structures, etc.) is needed to support these services. In recent years, a period of major drought has led to tree mortality and wildfires. Rainstorms following wildfires have caused debris slides, washouts, and erosion. Billions of dollars of damage to roads, trails, culverts, bridges, dams, campgrounds, buildings, and other infrastructure have been caused by...

A vulnerability assessment was conducted on the effects of climate change on infrastructure and outdoor recreation in the Sierra Nevada, including adaptation options that minimize negative impacts of climate change and facilitate a transition to a warmer climate. At vulnerable or flood-prone sites, resilience near stream crossings and in floodplains can be enhanced by designing infrastructure to withstand more frequent and severe flood events, and by upsizing or upgrading existing infrastructure to withstand flooding. Some roads and other infrastructure can be decommissioned or moved to...