Treesearch

In previous studies of an urban-rural land use gradient in the New York City metropolitan area, urban forest soils had higher heavy metal concentrations, soil temperatures, and abundances of earthworms than rural soils, while rural soils had higher abundances of fungi.

Predictions of future global warming suggest northward shifts of up to 800 km in the equilibrium distributions of plant species. Historical data estimating the maximum rate of tree distribution shifts (migration) suggest that most species will not keep pace with future rates of human-induced climatic change. Previous plant migrations have occurred at rates typically ranging from 15-50 km per century. A simulation model, which incorporates the effects of forest fragmentation and habitat loss, predicts maximum potential migration responses of trees may be only 1-10 km per century, or two...

Processes relating to tree regeneration are many and complex. To develop generalized conceptual models of tree regeneration, we synthesized information from the forest ecology literature.

The USDA Forest Service's Forest Inventory and Analysis (FIA) and the Natural Resource Conservation Service's State Soil Geographic (STATSGO) data bases provide valuable natural resource data that can be analyzed at the national scale. When coupled with other data (e.g., climate), these data bases can provide insights into factors associated with current and future ranges of tree species. However, a significant amount of data distillation is needed prior to such analyses. This paper describes the data base and geographic information system (GIS) processing involved with preparing the data...

We estimated total organic carbon storage (C -- kg m-2) in biomass, forest floor, and soil for a gently undulating glacial outwash landscape in east-central Minnesota (45° 25'N, 93° 10'W). Abandoned agricultural tracts are common, and nearly 40 percent of the area is wet mineral or organic soil. Quantitative models based on 745 point-observations were used to define empirical relationships between C storage and landscape variables describing forest cover type and terrain characteristics. Exponential regressions for individual cover types explained from 31 to 70 percent (p

The geographical ranges and spatial extent of outbreaks of herbivorous insect species are likely to shift with climatic change.

It is widely believed that tropospheric ozone presents a significant anthropogenic stress on forest ecosystems. Although much information has been collected regarding ozone effects at the seedling and leaf level, we do not have a reliable means of estimating the effect on mature, native forests. For the present study, we incorporated leaf-level ozone response information into an ecosystem model of forest production known as PnET-II in order to make whole-forest predictions that account for factors such as light attenuation, canopy ozone gradients and water stress. We ran the model using...

Long-term data sets are described in a catalog to reduce duplication of scientific efforts and to facilitate interaction among researchers.

The use of thermal scanning devices to map underlying terrain surface temperatures has been recognized as a potential tool for estimating evapotranspiration and latent heat flux densities in forest canopies.

In order to develop and evaluate models of net carbon exchange, we have collected profiles of CO2 through and above the canopy for extended periods over three years as well as collected short-term trial data of diurnal CO2, water vapor, and sensible heat fluxes above the canopy as measured by eddy correlation.