Treesearch

Hawaii is unique among the United States because of its tropical climate, geographic isolation, high rates of species endemism and discontinuous land mass. The year-round warm, wet climate on the windward sides of islands and the high fertility of relatively young volcanically derived soils are ideal conditions for carbon input, storage and carbon sequestration in ecosystems of the main Hawaiian Islands. A number of plot- and stand-level studies examining the physical and biological controls over tropical ecosystem carbon storage and flux provide evidence of the high carbon sequestration...

Ulmus americana (American elm) was an important urban tree in North America prior to the introduction of the Dutch elm disease pathogen in 1930. Subsequently, urban and community forests were devastated by the loss of large canopies. Tree improvement programs produced disease tolerant American and Eurasian elm cultivars and introduced them into the nursery industry. However, consumer acceptance was slow. The National Elm Trial was established to evaluate commercially available taxa of elm across the United States. Established at 16 locations, these plantings monitored survival and growth,...

Hemlock woolly adelgid (HWA), Adelges tsugae Annand, an invasive insect native to the Pacific Northwest and Asia, is responsible for widespread health decline and mortality of native hemlocks (Tsuga spp.) in the eastern United States. Shading and fertilizer has been found to affect the survival and health of both HWA and hemlocks. These abiotic factors have been studied separately but not in combination. In this three year study, eastern hemlock trees (1–2 m tall) were treated with pruning, fertilizer, and shade to determine their effects on hemlock tree health and HWA survival and...