Treesearch

On a high-quality site in the mixed conifer forest of northern California, understory and overstory vegetation along a 3-mile paved county road were manipulated to enhance the view for the traveler. Traditional silvicultural cutting methods and landscape architectural techniques were blended to give contrast and variability to the vegetation along both sides of the highway. Understory vegetation (hardwoods, shrubs, forbs, graminoids, ferns, conifer seedlings); saplings (hardwoods, conifers, shrubs); and trees (California white fir, sugar pine, coast Douglas-fir, incense-cedar, California...

A model of ethnic participation at undeveloped natural areas was developed and tested. The proposed model included the constructs of socio-economic status, perceived discrimination, assimilation, and ethnicity. Undeveloped natural areas were defined as being located outside of cities and primarily natural in composition. A telephone survey of a stratified random sample of Los Angeles County residents resulted in 894 interviews. The results demonstrate the multi-dimensional and complex nature of outdoor recreation participation. Despite close proximity and low entrance fees compared to...

Forests in the Ukraine are affected by environmental pollution, intensive forestry practice, and recreational uses. These factors make them sensitive to impacts of climate change. Since 1989 Ukraine has participated in the International Cooperative Program on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests). A network of monitoring plots has been established in 14 administrative regions and in the Crimea. From 1989 to 1995 the primary estimation criteria by the ICP Level 1 Program -- defoliation and discoloration of forest stands -- have been observed on 215...

In recent years, a forest monitoring program in the Czech Republic was extended into more detailed monitoring that aimed to describe the extent of changes in forest vitality and identify the nature and the main causes of these changes on local and regional scales. Studies were undertaken in six mountain areas in the Czech Republic. The program of regional forest monitoring is divided into three levels according to the extent of evaluation of the parameters of forest stand health and other components of the forest ecosystem. Level 1 is large scale monitoring in a 1 by 1 km grid of permanent...

Because Hungary has about 18 percent forest area, it is not as densely forested as most of the countries in Europe. Forests are dominated by native species such as oaks, beech, hornbeam, and other broadleaves. As a result of an intensive afforestation in the last 50 years, introduced species, such as black locust, Scots pine, and improved poplars were widely planted and forest area increased by 50 percent -- to 18,000 km2. Several observations in Hungary from the early 1980's detected an unusual amount and type of forest damage affecting native and introduced species. A shocking observation...

Growth and productivity of forests are important indicators for understanding the general condition and health of forests. It is very important that indicators detected during monitoring procedures afford an opportunity for direct or indirect evaluation of forest productivity and its natural and anthropogenic changes. Analysis of the U.S. Forest Health Monitoring (FHM) crown indicators showed that primary crown indicators are not enough for biological interpretation of collected data and estimation of potential tree growth. The length of crown is necessary for calculating meaningful crown...

Slovakia is a mountainous and forested country (40.6 percent forest cover) in central Europe and has a large variety of vegetation zones, forest types, and a rich diversity of forest tree species. The most important tree species are beech (Fagus sylvatica L.), Norway spruce (Picea abies Karst.), oak species (Quercus sp.), Scots pine (Pinus sylvestris L.), silver fir (Abies alba Mill.), European hornbeam (Carpinus betulus L.), European larch (Larix decidua Mill.), poplars and willows (Populus L. sp., Salix L. sp.), and other hardwood broadleaves. On the basis of results of the Forest Health...

Systematic assessment and observation (survey, inventory) of forests in Latvia has been underway since the 1700's. Latvia's forests are in the boreal/temperate forest zone and cover 44 percent of the country. Forest growing conditions are subdivided into five site class types: forests on dry mineral, wet mineral, wet peat, drained mineral, drained peat soils. The dominant tree species in Latvia are Scots pine (Pinus sylvestris L.), 39.7 percent; Norway spruce (Picea abies Karst.), 20.6 percent; and common birch (Betula pendula Roth.), 28.4 percent. Systematic assessment of air pollution...

Vitality inventories of Scots pine stands, the most common species in Poland, have been done since 1991 by using the ICP-Forest methodology. In Scots pine stands older than 40 years, 1,040 observation plots were established. Defoliation was used as the primary indicator of stand vitality. During 1991 to 1995, SO2 and NOx were measured at 1,417 forest locations using passive samplers. The interrelation between changes of precipitation amounts during the growing season and vitality of Scots zones with different air pollution levels was studied. The analysis was done in three zones of Poland:...

Effective management of forest resources requires access to current and consistent geospatial information that can be shared by resource managers and the public. Geospatial information describing our land and natural resources comes from many sources and is most effective when stored in a geospatial database and used in a geographic information system (GIS). The information on the location and condition of current vegetation is one of the key elements in resource management. Remote sensing data, such as aerial photographs, satellite imagery, aerial video, and data collected by other remote...