Treesearch

Phellinus noxius, the cause of brown root-rot disease, is an invasive fungal pathogen that causes a white rot among woody plants in Asia, Oceania, and Africa. Because the origin and diversity of this pathogen are unknown, it is difficult to predict its behavior and invasive capacity, especially under future climatechange scenarios. We characterized genetic relationships and ecological differences among P. noxius lineages across eastern Asia and Oceania to better understand evolutionary responses of the pathogen to environmental changes. Sequences of four loci (nuclear large subunit,...

Ecological resilience is essential for maintaining ecosystem services in an era of rapid global change, but successful attempts to operationalize it for managing ecosystems at risk have been limited. Clear formulation and application of ecological resilience concepts can guide ecosystem management so that it enhances the capacity of ecosystems to resist and recover from disturbances and provides adaptive space for periods of ecological reorganization. As originally defined, ecological resilience measures the amount of perturbation required to change an ecosystem from one set of processes...

The fungal pathogen Pyricularia grisea has been studied to evaluate its production of phytotoxins for the biocontrol of the buffelgrass (Cenchrus ciliaris L.) weed. A first investigation allowed to isolate several new and known phytotoxic metabolites. However, the further investigation on the organic extract obtained from the fungus liquid culture showed the presence of other metabolites possibly contributing to its phytotoxicity. Thus, four known metabolites were isolated and identified by spectroscopic (nuclear magnetic resonance [NMR] and high-resolution electrospray ionization mass...

Conflicting priorities for livestock grazing management in the context of rare plant conservation are common worldwide, especially in semiarid and arid ecosystems, where open-range livestock grazing is a primary land use. Detailed information on the interaction between livestock impacts and rare plant demography would facilitate improved management, yet this information is most often not available. In this study we examined the direct impacts of cattle trampling on dormant season survival of Astragalus holmgreniorum (Fabaceae), a globally endangered perennial spring ephemeral of the...

Complex, reciprocal interactions among climate, disturbance, and vegetation dramatically alter spatial landscape patterns and influence ecosystem dynamics. As climate and disturbance regimes shift, historical analogs and past empirical studies may not be entirely appropriate as templates for future management. The need for a better understanding of the potential impacts of climate changes on ecosystems is reaching a new level of urgency, especially in highly perturbed or vulnerable ecological systems. Simulation models are extremely useful tools for guiding management decisions in an era...

Prairie-forest ecotones are ecologically important for biodiversity and ecological processes. While these ecotones cover small areas, their sharp gradients in land cover promote rich ecological interaction and high conservation value. Our objective was to understand how historical and current fire occurrences and human development influenced the Palouse Prairie-forest ecotone. We used General Land Office survey field notes about the occurrence of bearing trees to locate historical (1870s to 1880s) prairie, pine savanna, and forest at the eastern edge of the bioregion. We combined LANDFIRE...

A solution to the growing problem of catastrophic wildfires in Greece will require a more holistic fuel management strategy that focuses more broadly on landscape fire behavior and risk in relation to suppression tactics and ignition prevention. Current fire protection planning is either non‐existent or narrowly focused on reducing fuels in proximity to roads and communities where ignitions are most likely. A more effective strategy would expand the treatment footprint to landscape scales to reduce fire intensity and increase the likelihood of safe and efficient suppression activities....

Wildland fire and bark beetle outbreaks are both large disturbances in North American forests with the potential to interact over spatial and temporal scales (Hicke et al. 2016; Raffa et al. 2008). The order of the disturbances, fire before bark beetles or fire after bark beetles, influences the outcome of the interaction. Fire and bark beetles are similar in that both can cause massive amounts of tree mortality, alter nutrient cycling, and alter forest structure and species composition, but these disturbances, in isolation and together, also have distinct effects on ecosystems. Several...

Conifer removal in interior woodland ecosystems of the western US is a common management treatment used to decrease fire hazard and shift woodlands to more historical states. Woody material is frequently removed by skidding material off site and via slash pile burning. Assessing the long-term outcomes of seeding treatments after such ground disturbing activities is critical for informing future management and treatment strategies. Using two designed experiments from a central Oregon juniper woodland, we resampled slash piles and skid trails 8 years after seeding. Our objectives were to...

The global COVID-19 pandemic will pose unique challenges to the management of wildland fire in 2020. Fire camps may provide an ideal setting for the transmission of SARS-CoV-2, the virus that causes COVID-19. However, intervention strategies can help minimize disease spread and reduce the risk to the firefighting community. We developed a COVID-19 epidemic model to highlight the risks posed by the disease during wildland fire incidents. Our model accounts for the transient nature of the population on a wildland fire incident, which poses unique risks to the management of communicable...