Treesearch

The United States Department of Defense (DoD) recognizes growing climate risks across its responsibilities as land manager, operator of hundreds of installations, and in its core mission to protect national security. However, DoD climate risk reduction is complicated by frequent leadership turnover among base commanders, which encourages focus on near-term challenges, and changing US government priorities that downplay climate risk. We used risk-based deliberation, through workshops, with climate scenario-based fire and flood impact modeling to evaluate risk and adaptation opportunities at...

With invasive grasses increasing wildfire occurrence worldwide, a better understanding of the relationships between native plants, fire, and invasive grass is needed to help restoration plans facilitate ecosystem resilience. Invasive grasses are particularly problematic for altering fire regimes in the tropics, yet in Hawai'i, restoration sites are often planted with monocultures of the native tree Acacia koa, which can promote grass growth via nitrogen fixation. This, combined with the difficulty of estimating pre-fire grass cover under thick canopies, complicates attempts to restore...

Climate change, with warming temperatures and shifting precipitation patterns, may increase natural-caused forest fire activity. Increasing natural-caused fires throughout western United States national forests could place people, property, and infrastructure at risk in the future. We used the fine K nearest neighbor (KNN) method coupled with the downscaled Multivariate Adaptive Constructed Analogs (MACA) climate dataset to estimate changes in the rate of natural-caused fires in western United States national forests. We projected changes in the rate of minor and major forest fires from...

In October 2020, under COVID-19 quarantine, AmeriFlux held its largest and one of its most successful annual meetings. Historically, ∼100 scientists attend; this meeting had over 400 registrants and participants. Participants expressed that this was among the best virtual meetings that they had ever attended, and 100% of post-meeting survey respondents stated that they would attend again. Feedback revealed the meeting fostered a strong sense of connection to the AmeriFlux community, especially among early career and international scientists. How did a feeling of strong connection to the...

Expanding the global protected area network is critical for addressing biodiversity declines and the climate crisis. However, how climate change will affect ecosystem representation within the protected area network remains unclear. Here we use spatial climate analogs to examine potential climate-driven shifts in terrestrial ecoregions and biomes under a +2 °C warming scenario and associated implications for achieving 30% area-based protection targets. We find that roughly half of land area will experience climate conditions that correspond with different ecoregions and nearly a quarter...

The cause of recent wildfire catastrophes can be traced to multiple factors, including the expanding urban footprint (Radeloff et al. 2018), human ignitions (Nagy et al. 2018), droughts (Littell et al. 2016) and high-wind events (Abatzoglou et al. 2018). In 2018, over 58,000 wildfires burned 8.8 million acres in the western U.S. (NIFC 2018). As wildfire frequency and intensity increase (Westerling 2016, Abatzoglou et al. 2017), understanding the impacts of high-severity wildfire on ecosystem function is critical, particularly the negative effects on soils (Certini 2005) and drinking water...

Sirex noctilio is a Eurasian species in the woodwasp (Siricidae) insect family, a small and poorly understood group of insects. Several siricid species have invaded various world regions due to their frequent presence in wood moving in international trade. Like most other woodwasps, feeding by S. noctilio occurs in weakened or dying pines in its native range, and populations exist there at relatively low levels. But in non-native regions of the Southern Hemisphere, S. noctilio populations have thrived, colonizing hosts in plantations of non-native pines planted at high densities. Under...

The effects of forest management on native fauna are of key interest to managers and conservationists. Individual studies have expanded our knowledge of management impacts, but meta-analyses of multiple studies are needed to summarize and integrate findings into a more generalizable form. Most meta-analyses on the effects of tree harvesting have focused on mature forest taxa because of concerns for these species; however, early-successional specialists, such as shrubland birds in the eastern United States, are also of key conservation concern. Using data from 34 studies that examined the...

Headwater forest ecosystems of the western USA generate a large portion of the dissolved organic matter (DOM) transported in streams across North America. Land cover changes that alter forest structure and species composition affect the quantity and composition of DOM transferred to aquatic ecosystems. Clear-cut harvesting affects ~1% of the forest area of North America annually, leaving most western forests in varying stages of regrowth and the total area of old-growth forest is decreasing. The consequences of this widespread management practice on watershed carbon cycling remain unknown....

In recent years wildland fires in the United States have had significant impacts on local and regional air quality and negative human health outcomes. Although the primary health concerns from wildland fires come from fine particulate matter (PM2:5), large increases in ozone (O3) have been observed downwind of wildland fire plumes (DeBell et al., 2004; Bytnerowicz et al., 2010; Preisler et al., 2010; Jaffe et al., 2012; Bytnerowicz et al., 2013; Jaffe et al., 2013; Lu et al., 2016; Lindaas et al., 2017; McClure and Jaffe, 2018; Liu et al., 2018; Baylon et al., 2018; Buysse et al., 2019)....