Treesearch

Land‐use/cover change (LUCC) is an important driver of environmental change, occurring at the same time as, and often interacting with, global climate change. Reforestation and deforestation have been critical aspects of LUCC over the past two centuries and are widely studied for their potential to perturb the global carbon cycle. More recently, there has been keen interest in understanding the extent to which reforestation affects terrestrial energy cycling and thus surface temperature directly by altering surface physical properties (e.g., albedo and emissivity) and land–atmosphere...

1 Previous research demonstrated that elevated sunlight improves carbon balance and growth of eastern hemlock (Tsuga canadensis (L.) Carrière) seedlings infested with the invasive hemlock woolly adelgid (Adelges tsugae Annand). 2 This study examined the hypothesis that elevated visible and ultraviolet sunlight directly affects the settling behaviour of A. tsugae crawlers. 3 Hemlock seedlings were manually infested with equal densities of A. tsugae and placedintoartificialshadetreatments(0%,40%and80%shade).Thedensityofsettled nymphsoftheensuinggenerationonshadedseedlingswasthreetimeshigherth...

Climate change is shifting both the habitat suitability and the timing of critical biological events, such as flowering and fruiting, for plant species across the globe. Here, we ask how both the distribution and phenology of three food-producing shrubs native to northwestern North America might shift as the climate changes. To address this question, we compared gridded climate data with species location data to identify climate variables that best predicted the current bioclimatic niches of beaked hazelnut (Corylus cornuta), Oregon grape (Mahonia aquifolium), and salal (Gaultheria...

The 2020 RPA Assessment includes climate change as a driver affecting natural resources on forests and rangelands in the United States. This publication describes the process used to select the scenarios, climate models, and climate projections that will be used to project renewable resource conditions 50 years into the future. Downscaled climate data selected are the MACAv2-METDATA developed by Abatzoglou and others at the University of Idaho. The dataset covers the conterminous United States at a grid size of approximately 4 km (1/24 degree) on a side. The two selected scenarios are the...

Removal of stumps and suppression of sprouts after harvesting by conventional methods, such as using heavy machinery or herbicides, alters the physico-chemical characteristics of soil, may cause environmental damage and can be very costly. In this study, the performance of inoculation with edible fungi as a biological alternative for stump degradation, has been examined in walnut plantations of five Spanish provinces. Stumps were inoculated with two species of edible fungi: Pleurotus ostreatus (Jacq. Ex Fr.) P. Kumm and Lentinula edodes (Berk) Pené. Compared with untreated controls, the...

Warming in arctic and boreal regions is increasing shrub cover and biomass. In southcentral Alaska, willow (Salix spp.) and alder (Alnus spp.) shrubs grow taller than many tree species and account for a substantial proportion of aboveground biomass, yet they are not individually measured as part of the operational Forest Inventory and Analysis (FIA) Program. The goal of this research was to test methods for landscape-scale mapping of tall shrub biomass in upper montane and subalpine environments using FIA-type plot measurements (n = 51) and predictor variables from imagery-based structure-f...

Aim: Communities with many species at their climatic niche limits may be vulnerable to species losses, suggesting that niche‐based measures can inform vulnerability assessments. We aimed to quantify spatial variation in community‐level vulnerability indices based on niche limits, not just central tendencies, to predict where climate changes will produce rapid, pronounced shifts in ecological communities. Location: North America. Taxon: Epiphytic lichenized fungi. Methods: We integrated broad‐extent herbarium data (46,343 North American sites, for estimation of realized niches) with...

There is growing interest in using Digital Aerial Photogrammetry (DAP) for forestry applications. However, the performance of pushbroom DAP relative to frame-based DAP and airborne lidar is not well documented. Interest in DAP stems largely from its low cost relative to lidar. Studies have demonstrated that frame-based DAP generally performs slightly poorer than lidar, but still provides good value due to its reduced cost. In the USA pushbroom imagery can be dramatically less expensive than frame-camera imagery in part because of a nationwide collection program. There is an immediate need...

Of California’s almost 100 million ac, about a third are forested (32 million ac). This report, including the accompanying tables, summarizes key findings from the 5,369 Forest Inventory and Analysis (FIA) plots measured in California’s forests during the period 2006–2015. Estimates are provided for forest area, ownership, species composition and distribution, size and age classes, volume, biomass, carbon, dead and downed wood, and understory vegetation. Starting in 2001, plots were measured on a 10-year cycle (10 percent of all plots measured annually). Thus, those plots measured in...

Climate change poses a clear danger to salmon and steelhead in the Columbia River basin. Rising water temperatures increasingly limit their ability to migrate, spawn, and successfully produce the next generation of fish.Steve Wondzell, a research ecologist with the USDA Forest Service’s Pacific Northwest Research Station, conducted a study on the upper Middle Fork of eastern Oregon’s John Day River. By using computer modeling, he and colleagues found that adding shade was the single most effective way to cool the water and preserve habitat for salmon into the future. With enough added...