Treesearch

Over the past few years, a number of improvements have been made to global surface air temperature datasets and climate models that facilitate increased statistical reliability when determining temperature anomalies and trends. Recent measurements show a continued rise in land surface temperatures, both globally and across the United States. These trends have been increasing since the 1970s with the world’s five warmest years on record (based on data since 1880) occurring since 2015. Maintaining consistent, high-quality water resources is a primary issue for public and environmental...

Soil resilience following harvest disturbance was studied at nine Long-Term Soil Productivity sites across the Sierra Nevada mountain range of California. We tested whether soil compaction, surface organic matter (OM) retention, and plant diversity have lasting effects on soil C, N, bulk density, or porosity. Study treatments following clearcut harvesting included soil compaction (none, moderate, severe) in factorial combination with three levels of OM retention (harvest slash retained, [OM2]; no slash retained, [OM1]; bare soil, [OM0]) and two plant diversity treatments (trees only; trees...

Snags (standing dead trees) are important components of forest ecosystems that, among other benefits, provide critical habitat for many species of wildlife, but also represent important safety concerns to firefighters, forest workers, and the public. We identified factors that influence the fall rates of lodgepole pines, Pinus contorta Dougl. ex Loud., killed by bark beetles during a severe regional-scale outbreak of mountain pine beetle, Dendroctonus ponderosae Hopkins, that occurred in 2004–2012. Data were obtained during annual assessments (2010–2019) of a network of 107 0.081-ha...

1. Understanding how plant populations respond to multiple drivers is increasingly critical for biodiversity conservation under global change. Indigenous knowledge can provide guidance for sustainable management, but the outcome of its application in novel ecosystems is rarely known. Simulating the re‐introduction of Indigenous stewardship in contemporary contexts with population models allows for the comparison of different management scenarios and the elucidation of the mechanisms driving population outcomes. 2. Beargrass Xerophyllum tenaxis an ecologically and culturally important...

After natural forest disturbances such as wildfires, windstorms and insect outbreaks, salvage logging is commonly applied to reduce economic losses and mitigate subsequent disturbance risk. However, this practice is controversial due to its potential ecological impacts, and its capacity to mitigate or increase the risk of subsequent disturbances remains unclear. Salvage logging removes and alters the legacies remaining after natural disturbances, and it produces additional management legacies. Consequently, salvage logging has the potential to alter the functional connection between...

Framing environmental issues in a sustainability context requires that we highlight the interdependencies between ecological, social and economic factors. Accordingly, the socio-ecological system (SES), which emphasizes the interplay between environmental and social dynamics, seems to be the appropriate framework for analysis. We applied this view to explore issues concerning the conservation of the remnant forests of the peri‑urban area of Bogota (Colombia). Specifically, we characterized this territory as a SES through a parsimonious set of fundamental, across-domain variables. Using...

Although the use of nonhost plants intercropped among host crops has been a standard agricultural practice for reducing insect herbivory for millennia, the use of nonhost signals to deter forest pests is much more recent, having been developed over the past several decades. Early exploratory studies with synthetic nonhost volatile semiochemicals led to targeted electrophysiological and trapping experiments on a variety of bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) across three continents. This work disclosed a suite of antennally and behaviourally active nonhost...

Mangrove forests have adapted to sea level rise (SLR) increases by maintaining their forest floor elevation via belowground root growth and surface sediment deposits. Researchers use surface elevation tables (SETs) to monitor surface elevation change (SEC) in mangrove forests, after which this information is used to assess SLR resiliency or to dictate active forest management for vulnerable systems. This method requires significant investments in terms of time and human resources and is limited in the number of points it can measure per plot. We use a low‐cost, portable terrestrial laser...

1. In mixed stands, species complementarity (e.g. facilitation and competition reduction) may enhance forest tree productivity. Although positive mixture effects have been identified in forests world‐wide, the majority of studies have focused on two‐species interactions in managed systems with high functional diversity. We extended this line of research to examine mixture effects on tree productivity across landscape‐scale compositional and environmental gradients in the low functional diversity, fire‐suppressed, mixed‐conifer forests of the U.S. Interior West. 2. We investigated mixture...

Host selection behaviour of the walnut twig beetle (WTB) among hardwood trees was investigated in a riparian forest in northern California by monitoring the landing rate of the beetle with sticky traps on branches baited with 3‐methyl‐2‐buten‐1‐ol, the male‐produced aggregation pheromone. The assay was conducted over 7 days (22 May to 29 May 2017) and compared landing rates on branches of six nonhost species paired with northern California black walnut, Juglans hindsii(the host). A total of 2242/1192 WTB were collected on branches of host/nonhost pairs, and more WTB landed on J. hindsiithan...