Treesearch

The tropical dry forest (TDF) biome has undergone a diversity of severe disturbances, with resulting transformations and continued pressures making this biome type one of the Earth’s most threatened. Supporting large numbers of native, often endemic species, fragments of TDF serve as important but precarious refugia. There are global efforts to restore this once extensive forest type, but the impact of TDF restoration on biodiversity and ecosystem function is poorly understood. Here, we present results from an analysis of 187 unique studies, published between January 1990 and February...

Evidence of unintended introductions of Phytophthoraspecies into native habitats has become increasingly prevalent in California. If not managed adequately, Phytophthoraspecies can become devastating agricultural and forest plant pathogens. Additionally, California’s natural areas, characterized by a Mediterranean climate and dominated by chaparral (evergreen, drought-tolerant shrubs) and oak woodlands, lack sufficient baseline knowledge on Phytophthorabiology and ecology, hindering effective management efforts. From 2018 to 2021, soil samples were collected from Angeles National Forest...

BackgroundThe increasing extent and severity of wildfires in the western USA poses a significant challenge to managers and to society. Forest thinning and prescribed fire treatments reduce fire hazard and improve resilience to climatic stressors. However, expanding the pace and scale of forest management is hampered, in part, by limited understanding and exposure of interested parties and the public to fuel reduction treatments. Virtual tour applications provide an opportunity to extend tours of treatment demonstration areas to anyone with a computer and internet connection. Yet there is...

This illustrated guide provides background information and guidance to help resource management professionals and land managers identify habitat restoration sites that have been affected by introduced root-rotting Phytophthora species. Restoration sites have become persistently infested with soilborne Phytophthora species by the planting of nursery stock with Phytophthora root rot. These infestations can spread beyond planted material into adjoining native vegetation, resulting in expanding areas of plant decline and mortality. Root-rotting Phytophthora species decay fine roots and may...

1. Considerable advances and breakthroughs in wildlife tracking technology have occurred in recent years, allowing researchers to gain insights into the movements and behaviours of a broad range of animals. Considering the accessibility and increase in use of tracking devices in wildlife studies, it is important to better understand the effects on these on animals. 2. Our endeavour revisits a guideline established in 1988, which proposes that bats may encounter body condition or health problems and alter their behaviour when carrying tags weighing more than 5% of their body mass. Through a...

Las pautas propuestas en Monitoreo de árboles urbanos: una guía de recursos (en adelante llamado la Guía de recursos) se crearon y depuraron a lo largo de muchos años para atender la necesidad de protocolos estandarizados para el monitoreo de árboles urbanos. La Guía de recursos ofrece orientación detallada a los encargados e investigadores de bosques urbanos que desean diseñar y poner en práctica un proyecto de monitoreo de árboles urbanos. Esta Guía de recursos es complemento de Monitoreo de árboles urbanos: una guía de campo; no obstante, la Guía de recursos también puede utilizarse por...

Este reporte proporciona protocolos detallados para la recolección de datos de monitoreo de árboles urbanos. Específicamente, se abordan las variables principales necesarias para los proyectos de monitoreo en campo, incluyendo la identificación de brigadistas, nivel de experiencia de brigadistas, registro del identificador del árbol, ubicación, tipo de sitio, uso del suelo, especie, estado de mortalidad, vitalidad de la copa y diámetro del tronco. La intención de esta Guía de campo es servir a los gestores de bosques urbanos e investigadores que recolectan datos de campo longitudinales...

Climate change is driving the emergence of novel tree diseases at the global scale, requiring new approaches for the formal confirmation of the pathogenicity of novel pathogens on novel hosts. At the same time, predictive models need to account for the possible effect of environmental changes and of abiotic stressors on disease severity for all diseases. By wound-inoculating Botryosphaeria dothidea on potted California coast live oaks and Cryptostroma corticale on potted silver maples, simultaneously in well-watered and in water-deprived conditions, I show that drought conditions increase...

We investigated the riverscape genetic structure of Klamath smallscale suckers (Catostomus rimiculus) in the Smith River, California, a population believed to have been introduced and founded by approximately six individuals within the last 100 years. Analyzing 15 microsatellites from larval samples across the species’ entire known Smith River range, we discerned: (1) increased genetic diversity downstream, (2) increased within-site differentiation upstream, and (3) isolation by river distance. These introduced suckers displayed a genetic profile expected for native species in river...

Release from interspecific competition can lead to niche shifts and have positive fitness consequences. I studied two closely related and ecologically similar Empidonaxspecies that breed across an elevational gradient in the southern Sierra Nevada, California: Dusky Flycatcher (Empidonax oberholseri) and Hammond’s flycatcher (E. hammondii). The two species coexisted at low and moderate elevations but only Dusky Flycatchers occurred in high elevation forests. Where they co-occurred, Dusky Flycatchers nested primarily in shrubs but at high elevations they nested primarily in trees and snags....