Treesearch

Metagenomics has illuminated our understanding of how microbial communities influence health and disease. Researchers are beginning to characterize what constitutes healthy microbiota in terms of structure, function, and diversity in a variety of environments. Although investigation lags behind the more well-studied human microbiome, a growing body of research is using next-generation sequencing tools and advances in bioinformatics to explore how microbiota and constitutive microbiomes in soils, and plant tissues can affect crop and forest diseases (Damon et al. 2012, Bonito et al. 2014,...

Hawai'i is a biological hotspot with a variety of climates and habitats. While fungal species diversity has been more extensively studied in Hawai'i than other Pacific Islands (e.g. see Gilbertson et al. 2002), there remain many species unreported in the literature. This project attempted to capture a small portion of Hawai'i's fungal diversity in southeast O'ahu by identifying fruit bodies using molecular techniques. The efficacy of using the internal transcribed spacer (ITS) and large subunit (LSU) regions of the nuclear ribosomal DNA (rDNA) to identify Hawai'ian fungi is discussed.

Although the islands of the western Pacific comprise a hotspot of species, including fungi, a large number of these species have not been catalogued or documented in the scientific literature on an island to island basis. Butt- and root-rot fungi were collected from infected wood and fruiting bodies of diverse tropical trees from forest, agricultural, and urban sites during an outreach/survey trip to USA-affiliated islands in the western Pacific including Palau, Yap, Guam, Saipan, Pohnpei, and Kosrae (Figure 1). Collections focused on the aggressive brown root-rot pathogen, Phellinus...

European ash (Fraxinus excelsior) is an important tree species in most temperate forests in Europe. Its future is threatened however, especially by an invasive fungus, Hymenoscyphus fraxineus (Hymenoscyphus pseudoalbidus, Chalara fraxinea). The current study is focused on the health of ash in the Krkonoše Mountains National Park, Czech Republic. On permanent research plots containing mixtures of ash and other species, the stands’ health condition was evaluated annually in 2009-2015, by using radial increment and foliage of 350 trees as indicators, with emphasis on the cenotic arrangement...

Longleaf pine (Pinus palustris Mill.) forests are characterized by unusually high understory plant species diversity, but models describing understory ground cover biomass, and hence fuel load dynamics, are scarce for this fire-dependent ecosystem. Only coarse scale estimates, being restricted on accuracy and geographical extrapolation, are available. We analyzed the dynamics of ground cover biomass under different prescribed burning regimes in longleaf pine stands in the southeastern United States. We developed a set of functions to simulate ground cover biomass dynamics in stands of...

In Western North America, increasing wildfire and outbreaks of native bark beetles have been mediated by warming climate conditions. Bioclimatic models forecast the loss of key high elevation species throughout the region. This study uses retrospective vegetation and fire history data to reconstruct the drivers of past disturbance and environmental change. Understanding the relationship among climate, antecedent disturbances, and the legacy effects of settlement-era logging can help identify the patterns and processes that create landscapes susceptible to bark beetle epidemics.

Large, severe disturbances drive many forest ecosystems over the long term, but pose management uncertainties when human experience with them is limited. Recent continent-scale outbreaks of bark beetles across the temperate Northern Hemisphere have raised major concerns as to whether coniferous forests will regenerate back towards pre-outbreak condition and meet possible reforestation objectives. To date, however, analyses of post-outbreak regeneration across broad spatial and temporal scales have been rare, and entirely lacking for many regions.

The history of land use in the American West has traditionally been one of conflict, but the divisive relationships between ranchers, foresters, land management agencies, recreational users, and conservationists are transforming. Grassroots coalitions have developed among unlikely allies. Together, they are advocating for management approaches that incorporate local knowledge, community needs, and sound environmental stewardship. This "collaborative conservation" is especially appropriate for promoting the conservation of working forests and rangelands, which are critical for maintaining...

Predicting lake level fluctuations of the Great Salt Lake (GSL) in Utah - the largest terminal salt-water lake in the Western Hemisphere - is critical from many perspectives. The GSL integrates both climate and hydrological variations within the region and is particularly sensitive to low-frequency climate cycles. Since most hydroclimate variable records cover less than a century, forecasting the predominant yet under-represented decadal variability of the GSL level with such relatively short instrumental records poses a challenge. To overcome data limitations, this study assesses two...

Sagebrush steppe ecosystems in the United States currently occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus urophasianus) is a landscape-dependent bird that requires intact habitat and combinations of sagebrush and perennial grasses to exist. In addition, other sagebrush-obligate animals also have similar requirements and restoration of...