Treesearch

Riparian ecosystems, the interface of terrestrial and aquatic systems, are zones of high biodiversity (Naiman et al., 1993), rapid biogeochemical activity (Vidon et al., 2010), complex hydrologic activity (Mayer et al., 2010a), and offer solace that can bestow significant mental health benefits (Alcock et al., 2014). Yet, many riparian zones also represent intersections of policy disputes, economic tradeoffs, and environmental degradation. A clearer understanding of science is necessary to establish better resource policy, identify economic values, stave off environmental impacts to...

We compared plants used as sites for nests and survival of nests of black-chinned hummingbirds (Archilochus alexandri) along two rivers in New Mexico. Along the free-flowing Gila River which was dominated by native plants, most nests were constructed in boxelder (Acer negundo). Along the flow-restricted Middle Rio Grande which was dominated by nonnative plants, most nests were constructed in nonnative plants such as Russian olive (Elaeagnus angustifolia) and saltcedar (Tamarix). Mean nest height varied among species of plants used as nesting sites but was about 4 m at each study area....

I've written the Climate-Aquatics Blog the last several years as a means of rapidly and broadly distributing peer-reviewed research pertaining to climate change and its effects on aquatic ecosystems. My intent in doing so has been to raise awareness, stimulate healthy debates and information exchanges, and engage with those concerned about this global phenomenon across a diversity of backgrounds and aquatic science disciplines. So far, so good, as the blog mailing list continues to grow and I've enjoyed dialogues with people all over the world. Based on the feedback I receive, blogging is...

These proceedings are a compilation of 14 papers that were presented at the regional meetings of the forest and conservation nursery associations in the United States in 2013. The Joint Northeast and Southern Forest Nursery Conference was held at the Holiday Inn City Centre, Lafayette, Indiana, July 22 to 25, 2013. Subject matter for the technical sections included nursery fertilization, black walnut research, and exploring the threat of hybrid Phytopthoras (and how to prevent this). Field trips included tours of the Purdue Department of Forestry and Natural Resources, the Hardwood Tree...

Black cherry (Prunus serotina) is a valuable hardwood timber species, and its value highly depends on the wood quality which is often threatened by insect pests. Transgenic black cherry plants that are more resistant to cambial-mining insects may reduce the occurrence of gummosis and have great economic benefits to landowners and the forest products industries utilizing black cherry lumber and logs. In this review, general information about black cherry and the problem of gummosis are introduced. The various strategies for gene containment, the possibility of using cyanogenesis to enhance...

There are four recognized clonal lineages of the pathogen Phytophthora ramorum. The two major lineages present in North America are NA1 and NA2. With a few exceptions, NA1 is found in natural forest ecosystems and nurseries, and NA2 is generally restricted to nurseries. Isolates from the NA1 and NA2 lineages were used to infect rhododendron, camellia, and California bay laurel in detached leaf assays to study the effects of lineage, temperature, and host on pathogenicity and host susceptibility. Isolates within both lineages were highly variable in their ability to form lesions on each...

Nursery plants are important vectors for plant pathogens. Understanding what pathogens occur in nurseries in different production stages can be useful to the development of integrated systems approaches. Four horticultural nurseries in Oregon were sampled every 2 months for 4 years to determine the identity and community structure of Phytophthora spp. associated with different sources and stages in the nursery production cycle. Plants, potting media, used containers, water, greenhouse soil, and container yard substrates were systematically sampled from propagation to the field. From 674...

Seedlings of three Eastern US forest species Quercus rubra (northern red oak), Quercus prinus (chestnut oak) and Acer rubrum (red maple) were inoculated by applying Phytophthora ramorum sporangia to stems at different inoculum densities with and without wounding. Disease occurred in all treatments involving wounds, and no disease was observed in unwounded treatments. Younger seedlings (2-3 years old) did not differ significantly from older seedlings (5-6 years old) in disease incidence, but older seedlings sustained smaller lesions compared with younger seedlings. For both old and young...

Forests and water are inextricably linked, and people are dependent on forested lands to provide clean, reliable water supplies for drinking and to support local economies. These water supplies are at risk of degradation from a growing population, continued conversion of forests to other land uses, and climate change. Given the variety of threats to surface water, it is important for forest managers to know how much of the drinking water supply originates in forests they manage and what populations and communities are served by that water. In this analysis, we used a hydrologic model,...

In order to better understand the dynamics of fire-atmosphere interactions and the role of micrometeorology on fire behaviour the FireFlux campaign was conducted in 2006 on a coastal tall-grass prairie in southeast Texas, USA. The FireFlux campaign dataset has become the international standard for evaluating coupled fire-atmosphere model systems. While FireFlux is one of the most comprehensive field campaigns to date, the dataset does have some major limitations especially the lack of sufficient measurements of fire spread and fire behaviour properties. In order to overcome this, a new,...