Treesearch

Few studies have quantified pathogen impacts to ecosystem processes, despite the fact that pathogens cause or contribute to regional-scale tree mortality.
We measured litterfall mass, litterfall chemistry, and soil nitrogen (N) cycling associated with multiple hosts along a gradient of mortality caused by Phytophthora ramorum, the cause of sudden oak death.
In redwood forests, the epidemiological and ecological characteristics of the major overstory species determine disease patterns and the magnitude and nature of ecosystem change. Bay laurel (Umbellularia californica) has high...

Anthropogenic nitrogen (N) deposition has had substantial impacts on forests of North America. Managers seek to monitor deposition to identify areas of concern and establish critical loads, which define the amount of deposition that can be tolerated by ecosystems without causing substantial harm. We present a new monitoring approach that estimates throughfall inorganic N deposition from N concentration in lichens collected on site. Across 84 study sites in western North America with measured throughfall, a single regression model effectively estimated N deposition from lichen N concentratio...

Forest systems are increasingly threatened by emergent, exotic diseases, yet management strategies for forest trees may be hindered by long generation times and scant background knowledge. We tested whether nursery disease resistance and growth traits have predictive value for the conservation of Notholithocarpus densiflorus, the host most susceptible to sudden oak death. We established three experimental populations to assess nursery growth and resistance to Phytophthora ramorum, and correlations between nursery-derived breeding values with seedling survival in a field disease trial....

Trabajos IndividualesEstas memorias resumen el resultado de un simposio diseñado para discutir los problemas actuales que confrontan las agencias con responsabilidad para la protección contra incendios forestales a nivel federal y estadual en los EE.UU., al igual que agencias en la comunidad internacional. Los temas discutidos en el simposio incluyen cambio climático e incendios forestales: realidad o ilusión?, teoría y modelos para la planificación estratégica de incendios, análisis económico y el manejo integral del fuego, incendios forestales y manejo sustentable de bosques, políticas...

One of the essential elements for a fire to occur is the flammable material. This is defined as the total biomass that has the ability to ignite and burn when exposed to a heat source. Fuel characterization in Mexican forest ecosystems is very scarce. However, this information is very important for estimating flammability and forest fire risk, fire behavior, environmental impact assessment and critical decision making related to fire management practices. The aim of this study was to determine the fuel load in a Eucalyptus sp. plantation, which has not been given any kind of management...

As provided for in the General Law on Sustainable Forestry Development, the Municipality of Villaflores has worked on a continuous basis since 2002 to reduce the damage caused by forest fires as part of its working agenda, in conjunction with Federal and State agencies and NGOs. The work plan has the following phases: a) Inter-agency coordination: participation of governmental agencies and NGOs; b) Pre-suppression: actions enabling the preparedness of resources (human, material and financial), highlighted by the establishment and operation of a Municipal Forest Fire Control Center; c)...

Algerian forest lands cover 4,115,908 hectares (ha), of which 2,413,090 (58%) ha are bush or maquis. Recent work has shown that forest fires are the main factor explaining (90%) degradation of Algeria forest lands at an annual rate of 45,000 to 50,000 ha. From 1985 to 2010 in 40 provinces of northern Algeria, 42,555 forest fires have burned a total of 910,640 ha. On average, 1,636 fires burn 35,024 ha of forest lands annually. The 1985 to 2010 period saw a general increasing trend in annual fire frequency for the area. As in the entire Mediterranean basin, forest fires in Algeria are...

The objective of this research was to characterize the spatial structure patterns of a Pinus hartwegii forest in the Sierra Madre Oriental, affected by a fire in 1998. Sampling was stratified by fire severity. A total of three fire severity classes (low, medium and high) were defined. Three sample plots of 40m x 40m were established for each severity. Variables obtained for all trees with a diameter at breast height (DBH) ≥ 5 cm in each plot were: DBH (cm) to 1.30 m, height (m), special location by recording the azimuth (°) and distance (m) from the center of the plot to each tree. A total...

Rainwater harvesting systems (RHSs) can be used to improve the efficiency of helicopter firefighting operations. To this end, RHSs need to be strategically located in areas with high wildfire occurrence to maximize their usefulness. In this study, spatial analysis was carried out to determine suitable sites for establishing RHSs intended for air attack operations in three municipalities (Chalco, Ixtapaluca and Tlalmanalco) located in the eastern part of the state of Mexico, Mexico. Five variables were used for site selection: wind speed, distance to roads, runoff, evaporation and wildfire...

The culture of fire in the context of climate change has become a complicated relationship between people and natural areas. The interaction between people and fire is not a new issue. The use of fire by humans in most aspects of life, especially in rural areas, together with rapid and haphazard growth of structures in wildfire-prone areas, has led to the owners and residents living there being less involved due to an urban conception of natural and forest areas. At the same time, rural areas have been decreasing and their populations aging due to migration to cities. Although the authoriti...