Treesearch

Large-diameter trees provide vital ecological functions in forested ecosystems. Old, large-diameter trees may also be vulnerable to climate-driven mortality events, but past work on large tree populations has been geographically limited. Here, we characterize the population of large-diameter trees from two size categories, 50 to 100 cm diameter at breast height (DBH) (medium) and >100 cm DBH (big), within the United States using Forest Inventory and Analysis data. Although populations of big trees are concentrated along the west coast, populations of medium trees are more evenly distributed...

The forests of coastal Alaska and British Columbia are globally significant for their high carbon storage capacity and complex forest structure, hosting some of the densest values of aboveground biomass in the world. These ecosystems support biodiversity, provide critical habitat, and serve as long-term carbon sinks, offering resilience to climate change. However, comprehensive, spatially continuous estimates of forest structure across this region have been limited, particularly across political boundaries. In this study, we used a Gradient Nearest Neighbor (GNN) modeling approach to...

Different sizes and shapes of field plots relative to raster grid cells were found to negatively affect lidar augmented forest inventory. This issue is called the “change of spatial support problem (COSP)” and caused biases and reduction in estimation efficiency (precision per number of plots). For a ∼14 000 km2 study area in Oregon State, USA, we examined three different plot shapes, both fixed-radius and cluster plots, alongside grid cell sizes ranging from 5 to 70 m. Effect size varied with the magnitude of spatial mismatch between plots and raster grid cells. There was up to 15% bias...

Temperature regulates the location, frequency, and extent of irruptive forest insect herbivore outbreak cycles. Across the Pacific coastal temperate rainforest, recent outbreaks by a native defoliator, western blackheaded budworm, have impacted the greatest land area recorded since the advent of aerial detection programs and led to widespread losses of canopy leaf area and forest growth. Evidence suggests that the geographic distribution of budworm outbreaks has tracked a poleward shift in suitable temperature across the ecoregion. In this manuscript, we compile aerial observer estimates...

High-elevation subalpine forests are experiencing rapid changes in climatic conditions, biological disturbances, and wildfire regimes. Despite this, evidence is mixed as to whether they will undergo major ecological transformation or be resilient to a confluence of global change drivers. Here we use subalpine fir (Abies lasiocarpa) and Englemann spruce (Picea engelmannii), which form co-dominant forests through much of the western United States, to investigate how species' demographic responses to global change influence forest community-wide resilience. We do this by adapting and building...

Ground-based measurements of smoke from prescribed fires in the southeastern US during the burning seasons of 2021 through 2024 are used to assess ozone (O3) and PM2.5 mass formation and their changes with age in 69 smoke events. O3 production occurred in nearly all plumes (31 out of 32) measured between 12:00 and 18:00. The O3 to carbon monoxide ratio (ΔO3/ΔCO) increased from 5.32 to 143 ppb ppm−1 as plumes aged from 1 to 480 min, showing a rapid initial increase, doubling in approximately 60 min, followed by a gradual slow down. Residual O3 from daytime fires was detected during the...

Managers often rely on predictions of species distributions and habitat suitability to inform conservation and management decisions. Although numerous approaches are available to develop models to make these predictions, few approaches exist to update existing models as new data accumulate. There is a need for updatable models to ensure good modeling practices in an aim to keep pace with change in the environment and change in data availability to continue to use the best-available science to inform decisions. We demonstrated a workflow to deliver predictive models to user groups within...

Gray fox (Urocyon cinereoargenteus) populations have apparently declined across the Midwestern United States which may be reflected in their distributional patterns and occupancy. To assess the severity of gray fox population declines and potential changing space use patterns, we used two temporally independent datasets collected using camera traps at the same sites during 2008–2010 and 2022–2023 within a 16,058-km2 area of southern Illinois, USA. We then developed three predictive occupancy models that allowed comparison of gray fox spatial patterns and occupancy estimates over time. We...

Riverine fishes face many challenges including habitat degradation and climate change, which alter the productivity of the riverscapes in which fish live, reproduce, and feed. Understanding the watershed portfolio of foraging and growth opportunities that sustain productive and resilient fish populations is important for prioritizing conservation and restoration. However, the spatiotemporal distribution and availability of fish food are poorly understood relative to other factors such as abiotic habitat quantity and quality (e.g., water temperature). In this paper, we build on the concept...

Food webs vary in space and time. The structure and spatial arrangement of food webs are theorized to mediate temporal dynamics of energy flow, but empirical corroboration in intermediate-scale landscapes is scarce. River-floodplain landscapes encompass a mosaic of aquatic habitat patches and food webs, supporting a variety of aquatic consumers of conservation concern. How the structure and productivity of these patch-scale food webs change through time, and how floodplain restoration influences their dynamics, are unevaluated. We measured productivity and food-web dynamics across a mosaic...