Treesearch

Accurate estimation of fuels is essential for wildland fire simulations as well as decisionmaking related to land management. Numerous research efforts have leveraged remote sensing and machine learning for classifying land cover and mapping forest vegetation species. In most cases that focused on surface fuel mapping, the spatial scale of interest was smaller than a few hundred square kilometers; thus, many small-scale site-specific models had to be created to cover the landscape at the national scale. The present work aims to develop a large-scale surface fuel identification model using...

Background: Native pinyon (Pinus spp.) and juniper (Juniperus spp.) trees are expanding into shrubland communities across the Western United States. These trees often outcompete with native sagebrush (Artemisia spp.) associated species, resulting in increased canopy fuels and reduced surface fuels. Woodland expansion often results in longer fire return intervals with potential for high severity crown fire. Fuel treatments are commonly used to prevent continued tree infilling and growth and reduce fire risk, increase ecological resilience, improve forage quality and quantity, and/or improve...

Understanding how human infrastructure and other landscape attributes affect genetic differentiation in animals is an important step for identifying and maintaining dispersal corridors for these species. We built upon recent advances in the field of landscape genetics by using an individual-based and multiscale approach to predict landscape-level genetic connectivity for grizzly bears (Ursus arctos) across ~100,000 km2 in Canada's southern Rocky Mountains. We used a genetic dataset with 1156 unique individuals genotyped at nine microsatellite loci to identify landscape characteristics that...

Diverse fungi collected from symptomatic fruit, stem and branch tissues of Theobroma cacao in five T. cacao-producing localities or municipalities of Mérida State, Venezuela, were identified using both morphological methods and sequencing of multiple loci (ITS, LSU, SSU, TEF1, BTUB, RPB2). Cophinforma atrovirens, Lasiodiplodia brasiliensis and Hypoxylon investiens are reported for the first time on T. cacao in Venezuela. Fungi found in association with fruit anthracnose included Cophinforma atrovirens, Fusarium solani and F. oxysporum, whereas species associated with dieback or sudden...

Surface fuel information is an essential input for models of fire behaviour and fire effects. However, spatially explicit, continuous information on surface fuel loads and fuelbed depth is scarce because the collection of field data is laborious, while suitable methods for deriving estimates from remote sensing data are still at an early stage of development. Fine-scale surface fuel mapping using both passive and active remote sensing has not yet been carried out in Central European forest types, and it remains unexplored how prediction uncertainties of different fuel components affect...

Frequent-fire forests were once heterogeneous at multiple spatial scales, which contributed to their resilience to severe fire. While many studies have characterized historical spatial patterns in frequent-fire forests, fewer studies have investigated their temporal dynamics. We investigated the influences of fire and climate on the timing of conifer recruitment in old-growth Jeffrey pinemixed conifer forests in the Sierra San Pedro Martir (SSPM) and the eastern slope of the Sierra Nevada. Additionally, we evaluated the impacts of fire exclusion and recent climate change on recruitment...

Forbs (wildflowers) are essential components of resilient, biologically and functionally diverse communities, but their use in restoration and rehabilitation in the Intermountain West remains limited. This guide is a companion field resource to the “Western Forbs: Biology, Ecology, and Use in Restoration” online book that synthesizes existing research on and practical experience with western forb species. This first volume field guide summarizes plant, seed, and fruit identification information, general species ecology, and important tips related to seed collection and planting. It is...

A deeper understanding of the influence of fine-scale fuel patterns on fire behavior is essential to the design of forest treatments that aim to reduce fire hazard, enhance structural complexity, and increase ecosystem function and resilience. Of particular relevance is the impact of horizontal and vertical forest structure on potential tree torching and large-tree mortality. It may be the case that fire behavior in spatially complex stands differs from predictions based on stand-level descriptors of the fuel distribution and structure. In this work, we used a spatially explicit fire...

The influence of forest treatments on wildfire effects is challenging to interpret. This is, in part, because the impact forest treatments have on wildfire can be slight and variable across many factors. Effectiveness of a treatment also depends on the metric considered. We present and define human-fire interaction, fire behavior, and ecological metrics of forest treatment effects on wildfire and discuss important considerations and recommendations for evaluating treatments. We demonstrate these concepts using a case study from the Cameron Peak Fire in Colorado, USA. Pre-fire forest...

Seed mass is an ecologically important trait that often differs considerably among ecotypes. Yet, because few studies examine the impacts of seed mass on adult life-history traits, its role in local adaptation is unclear. In this study, using accessions of Panicum hallii that spanned the two major ecotypes, we examined whether covariation between seed mass, seedling and reproductive traits impacts ecotypic divergence and local adaptation. The perennial grass P. hallii has two distinct ecotypes - a large-seeded upland ecotype adapted to xeric environments and a small-seeded lowland ecotype...