A5040126852- Fire effects on ecosystems
- Forest ecology and management
- Forest Insect Ecology and Management
- Ecology and Vegetation Dynamics Studies
- Forest Management and Policy
- Plant Water Relations and Carbon Dynamics
- Forest Ecology and Biodiversity Studies
- Tree-ring climate responses
- Bioenergy crop production and management
- Botany and Plant Ecology Studies
- Rangeland and Wildlife Management
- Remote Sensing and LiDAR Applications
- Species Distribution and Climate Change
- Plant and Fungal Interactions Research
- Genetic diversity and population structure
- Plant Pathogens and Resistance
- Arctic and Russian Policy Studies
- Plant responses to elevated CO2
- Yeasts and Rust Fungi Studies
- Insect and Pesticide Research
- Remote Sensing in Agriculture
- Peatlands and Wetlands Ecology
- Seedling growth and survival studies
- Plant Pathogens and Fungal Diseases
- Atmospheric and Environmental Gas Dynamics
Northern Arizona University
2015-2024
Pacific Southwest Research Station
2020
Oregon State University
2020
San Diego State University
2020
Astrogeology Science Center
2020
United States Geological Survey
2020
Southwest Biological Science Center
2020
Southern Research Station
2017
University of Montana
2005-2016
Rocky Mountain Research Station
2016
Abstract Interactions between extrinsic factors, such as disruptive selection and intrinsic genetic incompatibilities among loci, often contribute to the maintenance of species boundaries. The relative roles these factors in establishment reproductive isolation can be examined using pairs characterized by gene flow throughout their divergence history. We investigated process speciation boundaries Pinus strobiformis flexilis . Utilizing ecological niche modelling, demographic modelling...
Abstract Extant conifer species may be susceptible to rapid environmental change owing their long generation times, but could also resilient due high levels of standing genetic diversity. Hybridisation between closely related can increase diversity and generate novel allelic combinations capable fuelling adaptive evolution. Our study unravelled the architecture evolution in a hybrid zone formed Pinus strobiformis P. flexilis . Using multifaceted approach emphasising spatial patterns linkage...
A lack of optimal gene combinations, as well low levels genetic diversity, is often associated with the formation species range margins. Conservation efforts rely on predictive modelling using abiotic variables and assessments diversity to determine target populations for controlled breeding, germplasm conservation assisted migration. Biotic factors such interspecific competition hybridization, however, are largely ignored, despite their prevalence across diverse taxa role key evolutionary...
Abstract Oystershell scale (OSS; Lepidosaphes ulmi L.) is an invasive insect that threatens sustainability of aspen (Populus tremuloides Michx.) in the southwestern United States. OSS invasions have created challenges for land managers tasked with maintaining healthy ecosystems ecological, economic, and aesthetic benefits they provide. Active management required to suppress populations mitigate damage ecosystems, but before strategies can be implemented, critical knowledge gaps about biology...
In the past 150 years, southwestern ponderosa pine forests have become less resilient with altered ecological traits, such as higher tree densities, greater crown fire hazard, and lower understory cover. Treatments consisting of density reductions and/or prescribed burning been implemented increasing frequency to counteract effects these changes. The objectives this study were investigate treatments on resiliency attributes in second-growth stands located Vermejo Park Ranch, northern New...
The concept of ecological resilience is an invaluable tool to assess the risk state transitions and predict impact management on ecosystem's response future disturbances. However, difficult quantify factors contributing are often unknown in systems subject multiple Here, we develop demonstrate a framework potential ponderosa pine dry mixed conifer forests be resilient disturbance (recover as same forest type within managerially significant timeframe) by combining indicators short-term...
Finding trees that are resistant to pathogens is key in preparing for current and future disease threats such as the invasive white pine blister rust. In this study, we analyzed potential of using hyperspectral imaging find diagnose degree infection non-native rust southwestern seedlings from different seed-source families. A support vector machine was able automatically detect with a classification accuracy 87% (κ = 0.75) over 16 image collection dates. Hyperspectral only missed 4% infected...
Abstract Background Forest dieback driven by rapid climate warming threatens ecosystems worldwide. The health of forested depends on how tree species respond to during all life history stages. While it is known that seed development temperature-sensitive, little about possible effects and subsequent seedling performance. Exposure seeds high air temperatures may influence performance negatively, though conversely, aid acclimation seedlings thermal stress. Technical challenges associated with...
Over a century of fire exclusion in frequent-fire ponderosa pine and dry mixed conifer forests has resulted increased tree densities, heavy surface fuel accumulations an increase late successional, fire-intolerant trees. Grand Canyon National Park uses prescribed fires wildfires to reduce hazard restore ecosystem processes. Research is needed determine post-fire vegetation response thus enabling future forest succession predictions. Our study focussed on the effects burn entry severity...
The persistence of some tree species is threatened by combinations novel abiotic and biotic stressors. To examine the hypothesis that Pinus strobiformis Engelm., a an invasive forest pathogen changing climate, exhibits intraspecific genetic variation in adaptive traits, we conducted common garden study seedlings at one location with two watering regimes using 24 populations. Four key findings emerged: (i) growth physiological traits were low to moderately differentiated among populations but...
To improve the knowledge of ecosystem dynamics within frequent-fire forests and to develop targets for forest restoration, we dendrochronologically reconstructed four 1-ha plots dry mixed-conifer in northern Arizona, USA. Forest densities study area increased from 139.8 live trees ha−1, 10.26 m2 basal 14.9% canopy cover 1879 (the assumed year fire exclusion) 1,116.8 42.23 55.3% 2014. Shade-tolerant species also became more prevalent. Initial increases tree density occurred near established...
The phenotype of trees is determined by the relationships and interactions among genetic environmental influences. Understanding patterns processes that are responsible for phenotypic variation facilitated studying between environment many individuals across broad ecological climatic gradients. We used Pinus strobiformis, which has a wide latitudinal distribution, as model species to: (a) estimate relative importance different factors in predicting these morphological traits (b) characterize...
Tree mortality rates have been increasing globally with mountainous regions experiencing higher temperatures and impacts from the expansion intensification of pests invasion by non-native agents. Western North American high-elevation forests exemplify these trends, they often include one or more species five-needle white pines (High-5 hereafter). These share many characteristics critical to defining structure function subalpine forests. The main threats High-5 populations pathogen Cronartium...