Forest ecosystems water balance research is very complicated because of forest influence upon individual components of the water balance. Global climate changes represent a real threat for forest ecosystems. In hydric area these changes concern especially thermal balance and resulting increased evapotranspiration, time and spatial distribution of precipitation

This case study confirms the role of air pollution impact on forest susceptibility to other abiotic and biotic detrimental factors. It is however very important to take into account numerous contributing factors in order to interpret or predict the degree of damage correctly

Black pine (Pinus nigra Arn.) was chosen as bioindication species for several reasons. Black pine stands are located throughout Istria, at various distances from the above mentioned power plant. Black pine does not shed needles in the autumn, thus prolonging their exposure to sulphur dioxide emissions. Also neeedles stay on branches for several years, giving us the possibility to analyse the effect on older needles

Pasture management can be effective at sequestering soil organic C. We determined the depth distribution of particulate organic C (POC), non-particulate organic C (NPOC), particulate-to-total organic C (POC-to-TOC) ratio, and particulate organic C-to-N (POC-to-N) ratio under pastures near Watkinsville, GA, USA. POC was highly related with total organic C (TOC), but became an increasingly larger portion of TOC near the soil surface, where both pools were greatest. POC and NPOC were (i) greater under pasture than under conservation-tillage cropland, (ii) greater when pasture was grazed than when hayed, (iii) marginally greater with higher fertilization of pasture, (iv) greater with higher frequency of endophyte infection of tall fescue, and (v) greater under increasing stand age of grass. Soil under pasture comparisons that had greater TOC content had (i) larger improvements in POC than in NPOC and (ii) lower POC-to-N ratios, suggesting improvement in biochemical soil quality, as well as soil C sequestration.

Thirty Atriplex lines were examined for potential habitat improvement and phytoremediation of selenium (Se) contaminated sites. Studies were conducted to determine the biomass production, Se accumulation, and resistance of each line to the beet armyworm, Spodoptera exigua, an agriculturally important insect. Plants were tested using three salinity treatments: (1) control, no Se; (2) NaCl and CaCl2 salts and 1 mg l-1 Se (12.7 μM) added as sodium selenate; and (3) iso-osmotic to treatment 2 containing high concentrations of sulfate and 1 mg l-1 Se added as sodium selenate. Insect bioassays measured survival, growth, and development. Atriplex patula, A. spongiosa 415862, A. hortensis, A. hortensis 379088 and A. hortensis 379092 were among the top biomass producers and Se accumulators, yet they exhibited significantly reduced insect growth, development, and survival. High background sulfate strongly reduced Se accumulation, suggesting that phytoremediation potential is greatest in saline areas having low to moderate sulfate levels. However, these lines grew well in high salinity soils, indicating possible use as a self-seeding cover crop to improve habitat. All plant lines grown in control and high sulfate salinity treatments are acceptable oviposition sites for S. exigua, indicating that these plants would help reduce populations of this key agricultural pest.

In the North Tyrolean Limestone Alps a site was investigated over a four-year period (1998-2001) in order to assess the nitrogen saturation status, the nitrogen budget (quantification of the net uptake of nitrogen by the canopy and of the nitrogen mineralization, nitrogen uptake from roots and N2O emission rates, proof of the origin of nitrate in the soil water with stable isotope analyses, and the effects of the actual nitrogen input on ground water quality. The main goals were to quantify the nitrogen input rate, the nitrogen pools in above-ground and below-ground compartments, nitrogen turnover processes in the soil as well as the output into the groundwater and into the atmosphere. The findings are based on continuous and discontinuous field measurements as well as on model results

Atmospheric carbon dioxide (CO2) and ozone (O3) are increasing by 1-2% per year and are expected to double by the year 2100 compared to the end of the last millennium. Carbon dioxide at twice the current atmospheric concentrations has the potential to increase the productivity of forest trees while increasing ozone is expected to cause significant reductions in growth. The present study was undertaken to investigate the effects of CO2 and O3, singly or in combination, on growth and allocation of two European silver birch (Betula pendula Roth) clones under field conditions to verify the future predicitons in regard to silver birch. Our data show that growth of clone 80 was benefitted by ambient CO2 singly and in combination with ambient O3. Clone 4 was more responsive to ambient O3 than clone 80 which is opposite to results from previous pot experiments with these clones

Carbon sequestration in agricultural soils is controlled by the balance of added organic residues and microbial oxidation of both residues and native organic matter (OM) as moderated by management and tillage. The PC-based model CQESTR predicts decomposition of residues, organic amendments and soil OM, based on cropping practices. CQESTR uses RUSLE (Revised Universal Soil Loss Equation) crop rotation and management practice, crop production, and operation databases. These data are supplemented with residue nitrogen and soil OM, bulk density, and layer thickness. CQESTR was calibrated with soil carbon data from 70-year-long experiments at the Research Center at Pendleton, OR. The calibrated model provides estimates with a 95% confidence interval of 0.33% OM. Validation at 11 independent sites resulted in a matching of observed with calculated OM with a 95% confidence interval of 0.55% OM. A 12th site, with a history of severe erosion, provided a poor match.

Down deadwood (DDW) is a carbon component important in the function and structure of forest ecosystems, but estimating DDW is problematic because these data are not widely available in forest inventory databases. However, DDW data were collected on USDA Forest Service Forest Inventory and Analysis (FIA) plots during Maine's 1995 inventory. This study examines ways to predict DDW biomass from other FIA variables so that DDW could be estimated without tedious measurement. Our results include a regression model that predicts DDW as a function of stand size class, basal area of dead and cut trees, and dummy variables for forest type and forest industry ownership. We also found DDW similar to FIA's standing-tree mortality at a statewide scale.

Waste streams associated with a variety of agricultural runoff sources are major contributors of nutrients, pesticides and enteric microorganisms to surface and ground waters. Water soluble anionic polyacrylamide (PAM) was found to be a highly effective erosion-preventing and infiltration-enhancing polymer, when applied at rates of 1-10 g m (super -3) in furrow irrigation water. Water flowing from PAM treated irrigation furrows show large reductions in sediment, nutrients and pesticides. Recently PAM and PAM+CaO and PAM+Al(SO (sub 4) ) (sub 3) mixtures have been shown to filter bacteria, fungi and nutrients from animal wastewater. Low concentrations of PAM [175-350 g PAM ha (super -1) as PAM or as PAM+CaO and PAM+Al(SO (sub 4) ) mixture] applied to the soil surface, resulted in dramatic decreases (10 fold) of total, coliform and fecal streptococci bacteria in cattle, fish and swine wastewater leachate and surface runoff. PAM treatment also filtered significant amounts of NH (sub 4) , PO (sub 4) and total P in cattle and swine wastewater. This points to the potential of developing PAM as a water quality protection measure in combination with large-scale animal feeding operations. Potential benefits of PAM treatment of animal facility waste streams include: (1) low cost, (2) easy and quick application, (3) suitability for use with other pollution reduction techniques. Research on the efficacy of PAM for removal of protozoan parasites and viruses and more thorough assessment of PAM degradation in different soils is still needed to completely evaluate PAM treatment as an effective waste water treatment. We will present analysis and feasibility of using PAM, PAM+Al(SO (sub 4) ) (sub 3) , and PAM+CaO application for specific applications. Our results demonstrate their potential efficacy in reducing sediment, nutrients and microorganisms from animal production facility effluents. Abstract