Treesearch

Understanding animals' behavioral and physiological responses to pathogenic diseases is critical for management and conservation. One such disease, white-nose syndrome (WNS), has greatly affected bat populations throughout eastern North America leading to significant population declines in several species. Although tricolored bat (Perimyotis subflavus) populations have experienced significant declines, little research has been conducted on their responses to the disease, particularly in the southeastern United States. Our objective was to document changes in tricolored bat roost site use...

Larger and more severe wildfires are becoming more frequent and impacting different communities and human settlements. Much of the scientific literature and media on wildfires has focused on area of ecosystems burned and numbers of structures destroyed. Equally unprecedented, but often less reported, are the increasing socioeconomic impacts different people and communities face from wildfires. Such information seems to indicate an emerging need to account for wildfire effects on peri-urban or wildland urban interface (WUI) areas, newer socio-demographic groups, and disadvantaged communities...

The papers collected in this Special Issue tackle multiple aspects on how hydrological processes and water quality at local watersheds could be affected by climate change through hydrological modeling, statistical analysis, and field measurement. In addition, climate-change implications and adaptions based on research findings are discussed and are highly beneficial to local water resources managers and stakeholders. In addition, the studies in this collection provide a variety of research methods and approaches to tackle challenging questions faced by local watersheds under various...

High frequency (30 Hz) two-dimensional particle image velocimetry data recorded during a field experiment exploring fire spread from point ignition in hand-spread pine needles under calm ambient wind conditions are analysed in this study. In the initial stages, as the flame spreads approximately radially away from the ignition point in the absence of a preferred wind-forcing direction, it entrains cooler ambient air into the warmer fire core, thereby experiencing a dynamic pressure resistance. The fire-front, comprising a flame that is tilted inward, is surrounded by a region of downdraft....

Many dry conifer forests in the western United States were historically adapted to frequent low-to-moderate severity fires, but are increasingly susceptible to large, stand-replacing wildfires due to dramatically altered stand conditions and changing climate. The historic tree spatial patterns of mature stands in fire-adapted forests – individual trees, clumps of trees, and openings (ICO) – are associated with heightened resistance and resilience to fire. How this pattern develops over time, however, is not well understood and could help inform reforestation practices better designed to...

An estimated 128 M trees died during the 2012–2016 California drought, largely in the southern Sierra Nevada Range. Prescribed burning and mechanical thinning are widely used to reduce fuels and restore ecosystem properties, but it is unclear if these treatments improve tree growth and vigor during extreme drought. This study examined tree growth responses after thinning, prescribed burning, and extreme drought at the Teakettle Experimental Forest, a historically frequent fire mixed-conifer forest in the southern Sierra Nevada of California, USA. Mechanical thinning (no thin, understory...

Of the more than five hundred and fifty species of North American bark beetles (Coleoptera: Curculionidae, Scolytinae), approximately twenty species occasionally cause large amounts of tree mortality in conifer forests. During 2000–2020, trends in bark beetle impacts changed dramatically across North America compared to those observed during the mid- to late 20thcentury. We review tools and tactics available for bark beetle suppression and prevention and provide an overview of temporal and spatial trends in bark beetle impacts in North American forests during 2000–2020. Higher impacts were...

During stand initiation, the influences of silvicultural practices such as competing vegetation control and fertilization have been primarily examined in terms of stand-level growth rather than structural complexity. Understanding how intensive silvicultural treatments alter the long-term trajectory of stand development may be critical to meeting management objectives, such as habitat restoration, minimizing ladder fuels, or carbon sequestration. Previous studies have found mixed evidence for an effect of vegetation control and fertilization on structural complexity. Investigating how...

Global climate change has led to rising temperatures and to more frequent and intense climatic events, such as storms and droughts. Changes in climate and disturbance regimes can have non-additive effects on plant communities and result in complicated legacies we have yet to understand. This is especially true for tropical forests, which play a significant role in regulating global climate. We used understory vegetation data from the Tropical Responses to Altered Climate Experiment (TRACE) in Puerto Rico to evaluate how plant communities responded to climate warming and disturbance. The...

Bedrock vadose zone water storage (i.e., rock moisture) dynamics are rarely observed but potentially key to understanding drought responses. Exploiting a borehole network at a Mediterranean blue oak savanna site—Rancho Venada—we document how water storage capacity in deeply weathered bedrock profiles regulates woody plant water availability and groundwater recharge. The site is in the Northern California Coast Range within steeply dipping turbidites. In a wet year (water year 2019; 647 mm of precipitation), rock moisture was quickly replenished to a characteristic storage capacity,...