Treesearch

Opportunities are rare to study ecological primary succession and physical channel development in brand-new streams. An exception exists in streams recently formed atop extensive pyroclastic materials deposited during the 1980 eruption of Mount St Helens (USA), an area known as the Pumice Plain. Recent work demonstrated unexpectedly high diversity of benthic invertebrates in Pumice Plain streams at <4 decades post eruption, both within and among streams. Given the ecological importance of the hyporheic zone (HZ), we asked if differential development of HZs, both physically and biologically,...

In recent decades, evidence of interactions between aboveground and belowground (i.e., soil) subsystems has accumulated. The effects of aboveground vertebrates on belowground communities have traditionally focused on plant-mediated pathways, but we show that aboveground vertebrates impact belowground communities and ecological functions without plant-mediated pathways via both consumptive and non-consumptive processes. We then show that mobile, aboveground vertebrates have significant but often unrealized potential to structure soil communities from local to macroecological scales by...

The California Condor (CACO; Gymnogyps californianus) is a critically-endangered apex scavenger with multiple reintroduction sites providing population reinforcement. Spent lead ammunition pollution in CACO food (i.e., carrion and gut piles) was most likely responsible for the decline of CACO populations in the twentieth century and continues to be the leading source of condor mortality. To aid condor recovery decisions for the California population, numbering approximately 200 in early 2024, we present results from a female-only, individual-based life cycle model. We simulated future CACO...

Volcanic provinces are among the most active but least well understood landscapes on Earth. Here, we show that the central Cascade arc, USA, exhibits systematic spatial covariation of topography and hydrology that are linked to aging volcanic bedrock, suggesting systematic controls on landscape evolution. At the Cascade crest, a locus of Quaternary volcanism, water circulates deeply through the upper ∼1 km of crust but transitions to shallow and dominantly horizontal flow as rocks age away from the arc front. We argue that this spatial pattern reflects a temporal state shift in the deep...

Monitoring vegetation response to valley-scale floodplain restoration to evaluate effectiveness can be costly and time-consuming. We used publicly available National Agriculture Imagery Program (NAIP) data and commonly used ArcGIS software to assess land cover change over time at five study sites located in semi-arid environments of eastern Oregon and north-central California. Accuracy assessments of our unsupervised classifications were used to evaluate effectiveness. Overall accuracy across sites and years ranged from 64.2% to 89.2% with mean and median accuracy of 79.1% and 80.6%,...

At first glance, wood turtles may look like any other aquatic turtle—but they’re actually quite unique. Their carapace features elevated, concentric rings, resembling growth rings associated with trees. Unlike most other turtles, this semi-aquatic, freshwater species spends a substantial amount of time in terrestrial environments where it’s found in the upper midwestern and northeastern portions of the U.S. and southeastern Canada. Wood turtles are found predominantly in river systems with clean, highly oxygenated and medium- to fast-flowing streams for brumation—similar to hibernation in...

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...