Treesearch

The non-native invasive tree, Ailanthus altissima is an increasing threat to the diversity and health of temperate forests. Female trees are prolific producers of wind-dispersed seeds. It is not known if Ailanthus seeds remain viable in natural growing conditions beyond two years. We collected Ailanthus seeds from eleven sources in fall 2010 and incubated outdoors in either mixed oak leaf litter or mineral soil (10 cm depth) for five years to assess seed viability. Each May sets of seeds were retrieved, counted and sown in a greenhouse to measure germination. Initially germination rates...

We analyzed variations in three tree properties: tissue density, carbon fraction, and carbon density within bole tissues of nine Californian conifer species. Model performance for all three tree properties was significantly improved with the addition of covariates related to crown characteristics and position within the tree. This suggests that biomass and carbon mass estimates that rely on fixed wood density and carbon fraction may be inaccurate across tree sizes. We found a significant negative relationship between tissue density and carbon fraction within tree bole tissues, indicating...

IMPORTANCE: Neighborhood physical conditions have been associated with mental illness and may partially explain persistent socioeconomic disparities in the prevalence of poor mental health. OBJECTIVE: To evaluate whether interventions to green vacant urban land can improve selfreported mental health. DESIGN, SETTING, AND PARTICIPANTS: This citywide cluster randomized trial examined 442 community-dwelling sampled adults living in Philadelphia, Pennsylvania, within 110 vacant lot clusters randomly assigned to 3 study groups. Participants were followed up for 18 months preintervention and...

The Forest Service, U.S. Department of Agriculture, defines success in the wildland fire response environment as ìsafely achieving reasonable objectives with the least firefighter exposure necessary while enhancing stakeholder support for our management effortsî. However, persistent information and knowledge gaps challenge the agencyís ability to measure success in coming fire seasons. In this paper, we outline a roadmap to help fill these gaps, describing progress towards developing meaningful fire response key performance indicators (KPIs). We focus on characterizing suppression resource...

Rhizomorpha corynecarpos Kunze was originally described from wet forests in Suriname. This unusual fungus forms white, sterile rhizomorphs bearing abundant club-shaped branches. Its evolutionary origins are unknown because reproductive structures have never been found. Recent collections and observations of R. corynecarpos were made from Belize, Brazil, Ecuador, Guyana, and Peru. Phylogenetic analyses of three nuclear rDNA regions (internal transcribed spacer, large ribosomal subunit, and small ribosomal subunit) were conducted to resolve the phylogenetic relationship of R. corynecarpos....

This report assesses the potential for collaboration in New York State between the arts and field stations: places and programs where scientific researchers conduct long-term studies of diverse ecosystems. It provides an overview of how and where this transdisciplinary work is currently taking place, and makes recommendations to advance this effort across the state. It seeks to encourage further opportunities for artists that, when combined with environmental research, can aid community development and quality of life by advancing awareness of social-ecological systems: how people use,...

Black walnut (Juglans nigra L.), a large tree native throughout the eastern United States, produces a highquality edible nut. Our goal was to maintain the integrity of black walnut breeding programs by verifying the identity of accessions. We sampled 285 ramets of 78 cultivars from the black walnut nut breeding orchards and clonal repositories at the University of Missouri and Kansas State University. We employed both phenotypic and genotypic methods to identify and differentiate cultivars. Phenotypes were evaluated using seven phenological traits. Cultivars varied for all traits among...

The planning units of the National Forest System are beginning to revise their existing land management plans using the 2012 Forest Service regulations. Ecological integrity is a central concept to the regulations. However, implementing the concept is challenging in light of climate change. Historical ecology, particularly the concept of natural range of variation, informs planning for ecological integrity and climate change. This report discusses a March 2016 workshop held for the Intermountain Region to address ecological integrity, NRV, and climate change, all high priority topics for...

The smallmouth bass (Micropterus dolomieu) is a cool-water fish species native to central North America. Widespread introductions and secondary spread outside of its historical range have led to new recreational fisheries and associated economic benefits in western United States, but have also resulted in a number of ecological impacts to recipient ecosystems, including threats to Pacific salmon. Management of introduced smallmouth bass populations, now and into the future, relies on accurate detection and monitoring of this species. To address this need, we developed an environmental DNA...

Due to the interest in status and trends in forest resources, many countries conduct a national forest inventory (NFI). To better understand the characteristics of woody vegetation in areas that are typically not forested, there is an increasing emphasis on urban inventory efforts where all trees both within and outside forest areas are measured. Often, these two inventories are entirely independent endeavours from data collection through analytical reporting. To holistically explore landscape-scale phenomena across the rural-urban gradient, there is a need to combine information from both...