Treesearch

Limber pine, designated by Rocky Mountain National Park (RMNP) as a Species of Management Concern, is a keystone species that maintains ecosystem structure, function, and biodiversity. Limber pine is declining in the park due to the interacting effects of recent severe droughts and the climate-exasperated mountain pine beetle (Dendroctonus ponderosae) outbreak, and is threatened by the invasion of the non-native pathogen (Cronartium ribicola) that causes the lethal disease white pine blister rust (WPBR). White pine blister rust was confirmed in the park in 2010 (Schoettle et al. 2011;...

Airborne lidar has become a well-suited technology for predicting and mapping many tropical forest attributes, including aboveground biomass (AGB). However, trade-offs exist between lidar pulse density and acquisition cost. The aim of this study was to evaluate the influence of lidar pulse density on AGB change predictions using airborne lidar and field plot data in a tropical rain forest located near Paragominas, Pará, Brazil. In the field, AGB was computed at 84 square field plots of 50x50m in 2014. The lidar data were acquired 2012 and 2014, and for each dataset the pulse density was...

The three of us, combined, have organized or attended more than 500 events, including meetings, conferences, workshops, and symposia, around the world. After participating in so many events, we concluded that a guide for hosting a successful event is greatly needed. Too often, an event is negatively affected by preventable issues, such as poor planning, a terrible venue, unskilled speakers, ineffective moderators, bad food service, or technical difficulties. In this article, we provide practical guidelines for planning and executing smooth-running, well-received events.

Topographic diversity is the essence of mountain environments in western North America, a diversity that manifests itself hydrologically in a host of forms - rivers, streams, lakes, wetlands, and springs - that constitute habitats for a wealth of fish, amphibians, mussels, and insects. Some of those taxa, such as species of salmon and trout, are well studied icons of the region, whereas others are known only to dedicated naturalists or have yet to be described by science. Climatic controls on the distribution and abundance of aquatic taxa are of longstanding interest to aquatic ecologists...

Drought, a recurring phenomenon with major impacts on both human and natural systems is the most widespread climatic extreme that negatively affects the land carbon sink. Although twentieth-century trends in drought regimes are ambiguous, across many regions more frequent and severe droughts are expected in the twenty-first century. Recovery time - how long an ecosystem requires to revert to its pre-drought functional state - is a critical metric of drought impact. Yet the factors influencing drought recovery and its spatiotemporal patterns at the global scale are largely unknown. Here we...

Wild populations of Malus sieversii [Ldb.] M. Roem are valued genetic and watershed resources in Inner Eurasia. These populations are located in a region that has experienced rapid and on-going climatic change over the past several decades. We assess relationships between climate variables and wild apple radial growth with dendroclimatological techniques to understand the potential of a changing climate to influence apple radial growth. Ring-width chronologies spanning 48 to 129 years were developed from 12 plots in the Trans-Ili Alatau and Jungar Alatau ranges of Tian Shan Mountains,...

Extreme environmental events, such as storm winds, landslides, insect infestations, and wildfire, cause loss of life, resources, and human infrastructure. Disaster riskreduction analysis can be improved with information about past frequency, intensity, and spatial patterns of extreme events. Tree-ring analyses can provide such information: tree rings reflect events as anatomical anomalies or changed growth patterns at an annual- or even sub-annual resolution (Fig. 1). These centuries-long times series of paleo-events are far longer than historical records.

Wildfire increases the probability of debris flows posing hazardous conditions where values‐at‐risk exist downstream of burned areas. Conditions and processes leading to postfire debris flows usually follow a general sequence defined here as the postfire debris flow hazard cascade: biophysical setting, fire processes, fire effects, rainfall, debris flow, and values‐at‐risk. Prediction of postfire debris flow hazards is a problem of identifying and understanding the spatial and temporal interactions within this cascade. Models exist that can predict each or several components of the cascade...