Treesearch

Crown attributes respond readily to silvicultural manipulations and mediate many aspects of stand structure, consequently they dynamically influence stand production. Numerous studies reported crown structure responses to intensive cultures or stand density and the relation between foliage quantity and growth efficiency at early stages of stand development. Long-term temporal patterns of crown structure and its relation to growth have been much less studied. With long-term remeasurement data from two loblolly pine culture-by-density studies, the roles of planting density, cultural intensity...

This article offers the Extension community a pathway to drought resilience and climate-related conversations through knowledge exchange workshops. In 2017, a "flash drought" affected eastern Montana, and ranchers in the region faced numerous challenges. Moreover, drought-favorable climate conditions are predicted to increase for the region. We held five workshops to facilitate an exchange of adaptive drought management strategies, focusing on key themes for drought resilience: (a) drought planning and adaptive management, (b) use of local knowledge networks, (c) flexible stocking and...

This method paper explains the i-Tree Cool River model algorithms for simulating the response of river water temperature to urban greening. The model captures the warming and cooling impacts of urban development and restoration through a water and energy budget. The water budget includes river inflows from urban storm sewers and reservoirs, and the associated water temperatures. The energy budget adjusts radiation fluxes due to riparian shading and evapotranspiration, and propagates temperature downstream. Restorative cooling of the river can be simulated through algorithms for cool...

Increasing trends in wildfire severity can partly be attributed to fire exclusion in the past century which led to higher fuel accumulation. Mechanical thinning and prescribed burns are effective techniques to manage fuel loads and to establish a higher degree of control over future fire risk, while restoring fire prone landscapes to their natural states of succession. However, given the complexity of interactions between fine scale fuel heterogeneity and wind, it is difficult to assess the success of thinning operations and prescribed burns. The present work addresses this issue systematic...

Despite the enormous negative consequences of biological invasions, we have a limited understanding of how spatial demography during invasions creates population patterns observed at different spatial scales. Early stages of invasions, arrival and establishment, are considered distinct from the later stage of spread, but the processes of population growth and dispersal underlie all invasion phases. Here, we argue that the spread of invading species, to a first approximation, exhibits scale invariant spatial-dynamic patterns that transcend multiple spatial scales. Dispersal from a source...

Neonicotinoids are one of the most widely used classes of insecticides in the world. The neonicotinoid imidacloprid is commonly applied to hemlock (Tsuga spp.) stands in eastern North America to reduce tree mortality from infestations of the invasive hemlock woolly adelgid (HWA; Adelges tsugae). While laboratory and mesocosm studies have determined that imidacloprid can bioaccumulate in anurans and cause sublethal effects, no field studies have investigated whether salamanders or insects in streams adjacent to HWA treatments bioaccumulate imidacloprid or if sublethal effects are detectable...

The provision of ecosystem services is a prominent rationale for urban greening, and there is a prevailing mantra that 'trees are good'. However, understanding how urban trees contribute to sustainability must also consider disservices. In this perspective article, we discuss recent research on ecosystem disservices of urban trees, including infrastructure conflicts, health and safety impacts, aesthetic issues, and environmentally detrimental consequences, as well as management costs related to ecological disturbances and risk management. We also discuss tradeoffs regarding species...

The earliest reports of balsam woolly adelgid, Adelges piceae (Ratzeburg, 1844), in North America occurred in Maine in 1908 and California in 1928 (Kotinsky 1916, Annand 1928). By the late 1960s, this non-native pest was common throughout the ranges of native true fi r species, Abies spp. (Pinaceae) in the eastern United States and along the Pacifi c Northwest coast. In the interior west, Livingston et al. (2000) detected balsam woolly adelgid in Idaho in 1983, then observed declining health and death of subalpine fir, A. lasiocarpa (Hooker) Nuttall, over the next 15 years, primarily in...

Megafires are large wildfires that occur under extreme weather conditions and produce mixed burn severities across diverse environmental gradients. Assessing megafire effects requires data covering large spatiotemporal extents, which are difficult to collect from field inventories. Remote sensing provides an alternative but is limited in revealing post-fire recovery trajectories and the underlying processes that drive the recovery. We developed a novel framework to spatially reconstruct the post-fire time-series of forest conditions after the 1987 Black Dragon fire of China by integrating...

The photoload technique provides a quick and accurate means of estimating the loadings of six wildland fuel components including 1 hr, 10 hr, 100 hr, and 1,000 hr downed dead woody, shrub, and herbaceous fuels. It involves visually comparing fuel loading conditions observed in the field with a set of photographed sequences to estimate fuel loadings; the photo sequences are a series of downward-looking oblique photographs depicting a series of graduated fuel loadings of synthetic fuelbeds for each of the six fuel components. The photoload technique has been implemented into multiple...