Treesearch

Accurate prediction of dead fuel moisture content (FMC) is critical for wildfire management, particularly in the Hyrcanian forests of Iran. This study evaluates the performance of machine learning models - Random Forest (RF), Support Vector Machine (SVM), Gradient Boosting (GBoost), and Convolutional Neural Network (CNN) versus traditional linear regression methods in predicting FMC for three fuel classes (1-hr, 10-hr, and litter) over Golestan province, NE Iran. Using data collected from 235 plots between March and November 2023, we incorporated meteorological variables including temperatu...

National Forest Inventories monitor forest attributes across a variety of spatial and temporal scales in a given country. Increased interest in reporting and management at smaller scales has driven National Forest Inventories to investigate and adopt small area estimation (SAE) due to the promise of increased precision at these scales. However, comparing and evaluating SAE models for a given application is inherently difficult. Typically, many areas lack enough data to check unit-level modeling assumptions or to assess unit-level predictions empirically; and no ground truth is available...

Nationwide Forest Inventories (NFIs) collect data on and monitor the trends of forests across the globe. Users of NFI data are increasingly interested in monitoring forest attributes such as biomass at fine geographic and temporal scales, resulting in a need for assessment and development of small area estimation techniques in forest inventory. We implement a small area estimator and parametric bootstrap estimator that account for zero-inflation in biomass data via a two-stage model-based approach and compare the performance to a Horvitz-Thompson estimator, a post-stratified estimator, and...

The National Forest Inventory (NFI) for the USA draws sample data from all lands with equal intensity. Non-response in the NFI tends to be low on public lands relative to private lands, but this research documents higher rates of missing and delayed field plot measurements in wilderness areas relative to other federal lands in the contiguous westernUS. Given the extent and unique management directives of federal wilderness, discrepancies in field plot completion rates over this region could induce non-response bias in estimators of forest conditions at county or state levels. Further...

Developing tools for rapidly predicting which introduced species will become invasive is essential for effective management. It’s also notoriously difficult. Quantitative models exist but often require extensive data, precluding timely application. A qualitative modeling approach, Fuzzy Interaction Webs (FIW), offers a practical alternative. FIWs hold the potential to predict impacts, guide early responses, and identify research needs using the limited data commonly available on an invasion front. As a case study, we applied FIWs to predict effects of introduced European praying mantis (...

In 2020, numerous large wildfires, including the largest in Colorado history, burned watersheds that supply agricultural, industrial, and domestic drinking water to both sides of the Continental Divide. Increases in the size and frequency of severe wildfires such as these burning in headwater forests have implications for downstream water supply and aquatic ecosystems across western North America. Here, we evaluate stream water chemistry in 16 tributaries spanning a range of wildfire extent and severity during the first four years after the Cameron Peak Fire. As expected, stream water...

Pile burning is a common practice used to reduce woody debris generated by forestry operations. Combustion of the accumulated fuels generates high temperatures that penetrate into soils, producing highly alkaline, nutrient-rich ash. Little is known about the immediate influence of pile burns on underlying soils or the short-term chemical changes that may regulate post-fire soil microbiome and vegetation recovery. Here we present water-soluble solute concentrations extracted from ash, underlying burned organic matter and mineral soil of six burn piles. Sampling began within days of pile...

This chapter explores the snow and hydrological processes characteristic of steep, cold-region montane forested watersheds, particularly in western North America, which rely heavily on snowmelt as a critical water source for ecosystems and human use. While many hydrological principles discussed in other chapters apply to these high-elevation regions, the unique interactions among surface runoff, shallow lateral flow and baseflow merit special attention, particularly in the context of snow processes and steep terrain. The principles outlined here are broadly relevant to forested ecosystems...

Understanding the factors shaping trophic niche breadth is crucial for predicting species interactions, community assembly, and ecological responses to environmental change. Several hypotheses have been proposed to explain global variation in species’ trophic niches, but empirical tests are limited. Here, we used stable isotope analysis (δ13C and δ15N) to quantify trophic niche breadth of 541 fish populations (358 species, 82 families) from freshwater ecosystems encompassing diverse environmental conditions and six biogeographic regions. Fourteen hypotheses relating niche breadth to...

Hydraulic vulnerability, the sensitivity of xylem embolism to water stress, is a major determinant trait associated with conifer mortality. This study investigated branch P50 (50% hydraulic conductivity loss) of adult and juvenile ponderosa pines across multiple locations in the southwestern United States (SWUS), and examined relationships between P50 and climatic conditions, soil properties and forest management. Juvenile ponderosa pines had significantly more negative P50 values than adults on average. Both age groups exhibited a latitudinal pattern in P50 associated with regional...