Treesearch

Many Douglas-fir plantations along the north coast of Oregon are exhibiting severe symptoms of Swiss needle cast disease (SNC). These symptoms include premature loss of foliage, abundant fungal pseudothecia on needles, yellowing of foliage, and apparent reduction in diameter and height growth. The development of the disease and its impacts on growth are currently being monitored at three different levels: (l) annual aerial surveys to determine extent of SNC symptoms; (2) plantation surveys to assess the extent of SNC damage and to ground-truth aerial surveys; and (3) intensively measured...

Trees in urban ecosystems play a very significant role in environmental protection by checking air and noise pollutants, abating wind, and handling many other functions, in India, Chandigarh is the most modern and environmentally safe city and qualifies to be called a GREEN CITY because of its rich tree component. This is so in spite of its high population density, currently over 9,443 people per square km, perhaps the highest in the country. It has nearly 42,000 trees growing along the roads in a systematic manner. The drives are identified with the type of multipurpose tree species....

White-tailed deer (Odocoileus virginianus) herbivory has been identified as a major impediment to the survival and growth of forest regeneration in the northeastern United States. As a supplement to direct control of deer densities through hunting, it may be possible for land managers to manipulate habitat and browsing pressure through carefully planned timber harvest. We are developing methods to relate deer habitat use patterns to regeneration condition and complexity across large landscapes. The preliminary research presented here involved development of methodology to efficiently and...

Inventory data of Mexico City's street trees were studied using classical statistical arboricultural and ecological statistical approaches. Multivariate techniques were applied to both. Results did not differ substantially and were complementary. It was possible to reduce inventory data and to group species, boroughs, blocks, and variables.

The aim of this paper is to determine tile optimal physiological indicator in diagnosing the condition of tree stands under the stress of industrial pollution. Based on experimental results of the fumigation on pine seedlings with sulphur dioxide, acid rain treatment, and the effect of heavy metals on the seedlings, it is reasonable to use the secondary substances or the so called stress metabolites for this purpose. The greatest changes under the stress of industrial pollution are in the content of essential oils in pine needles. The contents of essential oils were examined and compared...

A partnership of state and federal agencies and private organizations is developing advanced spatial analysis techniques applied for conservation and restoration of forested wetlands. The project goal is to develop an application to assist decisionmakers in defining the eligibility of land sites for entry in the Wetland Reserve Program (WRP) of the U.S. Department of Agriculture. The WRP is one of the most successful programs in restoring wetlands on marginal agriculture lands. For this effort, three 7.5-minute quadrangles in Louisiana (Indian Lake, Newlight, and Saranac) were used as a...

As interest grows in the role of forest growth in the carbon cycle, and as simulation models are applied to predict future forest productivity at large spatial scales, the need for reliable and field-based data for evaluation of model estimates is clear. We created estimates of potential forest biomass and annual aboveground production for the Chesapeake Bay watershed region from USDA Forest Service Forest Inventory and Analysis data. These estimates were developed primarily for model evaluation and represent the pilot phase of an effort to estimate potential and actual forest biomass and...

A highly-automated procedure for remotely estimating individual tree location, crown diameter, species class, and height has been developed. This procedure will involve the use of a multimodal airborne sensing system that consists of a digital frame camera, a scanning laser rangefinder, and a position and orientation measurement system. Data from the multimodal sensing system will be processed by a model-based procedure for the recognition of individual tree crowns in aerial images. Both the multimodal sensing and tree crown recognition components have been separately tested, and data to...

A model was developed that predicts the probability of survival for individual shortleaf pine (Pinus echinata Mill.) trees growing in even-aged natural stands. Data for model development were obtained from the first two measurements of permanently established plots located in naturally occurring shortleaf pine forests on the Ouachita and Ozark National Forests in western Arkansas and eastern Oklahoma.

Landsat Thematic Mapper (TM) and SPOT Satellite Imagery were used to map wetland plant species in thc Coeur d'Alene floodplain in northern Idaho. This paper discusses the methodology used to create a wetland plant species map for the floodplain. Species mapped included common cattail (Typha latifolia); water horse-tail (Equisetum fluviatile); water potato/arrowhead (Sagittaria spp.); and wild rice (Zizania aquatica). Useful classifications were derived and lessons were learned about the timing of image acquisition and field data collection. This will guide improved classifications in the...