Treesearch

Progress is being made to build the science foundation for effective limber pine management. The power of repeated monitoring assessments now provides valuable condition trends for limber pine (Smith et al. 2013, Cleaver et al. 2015). In Canada, the proportion of dead limber pine increased from 2003-2004 and 2009 and WPBR infection increased from 33% to 43% putting some populations at risk for extirpation (Smith et al. 2013). In northern Colorado, Wyoming, and southeastern Montana 73% of the stands have been invaded by white pine blister rust (WPBR) with an average disease incidence of...

Snowshoe hares (Lepus americanus) are an ecologically important herbivore because they modify vegetation through browsing and serve as a prey resource for multiple predators. We implemented a multiscale approach to characterize habitat relationships for snowshoe hares across the mixed conifer landscape of the northern Rocky Mountains, USA. Our objectives were to (1) assess the relationship between horizontal cover and snowshoe hares, (2) estimate how forest metrics vary across the gradient of snowshoe hare use and horizontal cover, and (3) model and map snowshoe hare occupancy and intensity...

As an international group of taxonomists who study a range of taxa, we consider that you misconstrued the case of a new insect species that was described on the basis of photographs (see Nature 535, 323–324; 2016).

Many pest and beneficial insects overwinter as larvae in a state of diapause, with development resuming in the spring. In these cases, rates of post-diapause development of parasitoids must be synchronised with the vulnerable life stages of their hosts. Phenological asynchrony between introduced parasitoids and their targeted hosts has limited the success of some biological control efforts. Here, we assess the potential synchrony between Collyria catoptron Wahl (Hymenoptera: Ichneumonidae), a parasitoid of the Chinese wheat stem sawfly, Cephus fumipennis Eversmann (Hymenoptera: Cephidae),...

Mountain fens found in western North America have sequestered atmospheric carbon dioxide (CO2) for millennia, provide important habitat for wildlife, and serve as refugia for regionally-rare plant species typically found in boreal regions. It is unclear how Rocky Mountain fens are responding to a changing climate. It is possible that fens found at lower elevations may be particularly susceptible to changes because hydrological cycles that control water tables are likely to vary the most. In this study, we fit models of growing season ecosystem-atmosphere CO2 exchange to field-measured data...

The persistence of ponderosa pine and lodgepole pine forests in the 21st century depends to a large extent on how seedling emergence and establishment are influenced by driving climate and environmental variables, which largely govern forest regeneration. We surveyed the literature, and identified 96 publications that reported data on dependent variables of seedling emergence and/or establishment and one or more independent variables of air temperature, soil temperature, precipitation and moisture availability. Our review suggests that seedling emergence and establishment for both species...

The conventional approach to LiDAR-based forest inventory modeling depends on field sample data from fixed-radius plots (FRP). Because FRP sampling is cost intensive, combining variable-radius plot (VRP) sampling and LiDAR data has the potential to improve inventory efficiency. The overarching goal of this study was to evaluate the integration of LiDAR and VRP data. FRP and VRP plots using different basal-area factors (BAF) were co-located in 6 conifer stands near Alberta, Michigan, in the United States. A suite of LiDAR metrics was developed for 24 different resolutions at each plot...

Information needs associated with sustainable forest management are evolving rapidly as the forest sector works to satisfy an increasingly complex set of economic, environmental, and social policy goals. A barrier to the sustainable management of forests and the provision of ecosystem goods and services under these new pressures is a lack of up-to-date and detailed information with regard to the number and characteristics of forest resources. Accurate inventory systems are required that spatially quantify timber and other nontimber goods and services at multiple scales in order to inform...

Fire is a key earth-system and Anthropocene process (Bowman et al. 2009; Smith et al. 2016a). Fire impacts on the global carbon (C) cycle from both anthropogenic and natural sources, with 1350-3400 Tg C emitted from land-use changes, agricultural practices and residential uses, and 2750-4600 Tg C emitted in wildfire events, which exhibit high interannual variability (Westerling et al. 2006; van der Werf et al. 2010; Wotton et al. 2010; Balch et al. 2013; Lannom et al. 2014; Smith et al. 2016a). Biomass burning emissions can be determined from top-down assessments such as the Global Fire...

Following typical forest inventory protocols, individual tree volume estimates are generally derived via diameter-at-breast-height (DBH)-based allometry. Although effective, measurement of DBH is time consuming and potentially a costly element in forest inventories. The capacity of airborne light detection and ranging (LiDAR) to provide individual tree-level information poses options for estimating tree-level attributes to enhance the information content of forest inventories. LiDAR provides excellent height measurements and, given the physiologic scaling connection of plant height and...