Treesearch

Over the course of 1681 hours between May 5 and September 30, 2006, air temperatures measured at the 1.5-m height at seven sites in and near the city of Baltimore, MD were used to empirically model Δ Tˆ R-p , the difference in air temperature between a site in downtown Baltimore and the six other sites. Variables in the prediction equation included difference between the downtown reference and each of the other sites in upwind tree cover and impervious cover as obtained from 10-m resolution geographic information system (GIS) data. Other predictor variables included an index of atmospheric...

Plant species with wide distributions may differ in their population dynamics across their range, especially in contrasting habitats. Most tiller recruitment of perennial grasses occurs vegetatively from the belowground bud bank rather than from seed. Seed reproduction often occurs under a narrower range of environmental conditions than vegetative reproduction. As a result flowering and seedling recruitment patterns of a species often differ between contrasting habitats and across its range. How vegetative reproduction and bud bank dynamics of a species vary between contrasting habitats...

In this Natural Inquirer Freshwater edition, you will learn many new things about Earth’s freshwater. In "Green Means Clean," you will learn how scientists and managers are protecting U.S. drinking water supplies using better land management practices. Water pollution that cannot be traced to a particular source is the subject of "What’s the Nonpoint?" You will learn how the amount and type of living, or once-living, matter in a waterway changes over time in "Caribbean Cruise." Have you ever wondered whether chemicals flowing into urban waterways are dangerous? You will learn whether those...

Tiller recruitment from the belowground bud bank of caespitose grasses influences their ability to monopolize local resources and, hence, their genet fitness. Differences in bud production and outgrowth among tiller types within a genet and among species may explain co-occurrence of caespitose grasses. This study aimed to characterize genet bud-bank and tiller production and dynamics in two co-occurring species and compare their vegetative reproductive strategies.This publication was published prior to the author's employment with the US Forest Service. The "Download" button on this page...

In 2002, a wildfire burned over an ongoing sediment flux study in the steep, chaparral-covered foothills of the San Gabriel Mountains of southern California. The study area had previously burned in 1960. Southern California experiences a Mediterranean climate with cool wet winters and hot dry summers. Average annual rainfall for the study area is 714 mm (80-year record) with an average two-year 30-minute peak intensity of 29 mm hr-1. Hillslope erosion was measured in 30 cm collector traps. These traps were serviced multiple times per year to distinguish wet season from dry season erosion....

Models that quantify the probability of stump sprouting P(s) and sprout characteristics for predominant tree species in the southern Appalachian Mountains, USA are lacking. In this study, 375 plots (0.01 ha) were installed across five stands in eastern Tennessee and western North Carolina. Trees C3.8 cm diameter at 1.37 m above groundline (dbh) were tagged, and dbh and species recorded. Stands were regenerated using a two-aged silvicultural system (residual basal area (BA) \6.3 m2 ha-1 ). One growing season post-harvest, we recorded (1) sprouting (yes/no), (2) the number of sprouts per...

The mountain pine beetle-killed lodgepole pine (Pinus contorta) wood treated with iron (III) nitrate solution was used for the preparation of Fe-cored carbon nanomaterials (Fe-CNs) under various carbonization temperatures. The carbonization yield of Fe-treated sample (5% as Fe) was always 1–3% higher (after ash compensation) than that of the non-treated samples heated at the same condition.The lowest carbonization temperature required to produce Fe-CNs was 700° C. The carbon shell was composed of 30–40 well-aligned layers of graphitic carbon nanostructure.The iron captured by graphitic...