Use of pyrolysis molecular beam mass spectrometry (py-MBMS) to characterize forest soil carbon: method and preliminary results

The components of soil organic matter (SOM) and their degradation dynamics in forest soils are difficult to study and thus poorly understood, due to time-consuming sample collection, preparation, and difficulty of analyzing and identifying major components. As a result, changes in soil organic matter chemical composition as a function of age, forest type, or disturbance have not been examined. We applied pyrolysis molecular beam mass spectrometry (py-MBMS), which provides rapid characterization of SOM of whole soil samples. to the Tionesta soil samples described by Hoover, C.M., Magrini, K.A., Evans, R.J., 2002. Soil carbon content and character in an old growth forest in northwestern Pennsylvania: a case study introducing molecular beam mass spectrometry (PY-MBMS). Environmental Pollution 116 (Supp. 1), S269-S278. Our goals in this work were to: (1) develop and demonstrate an advanced, rapid analytical method for characterizing SOM components in whole soils, and (2) provide data-based models to predict soil carbon content and residence time from py-MBMS analysis. Using py-MBMS and pattern recognition techniques we were able to statistically distinguish among four Tionesta sites and show an increase in pyrolysis products of more highly decomposed plant materials at increasing sample depth. For example, all four sites showed increasing amounts of older carbon (phenolic and aromatic species) at deeper depths and higher amounts of more recent carbon (carbohydrates and lignin products) at shallower depths. These results indicate that this type of analysis could be used to rapidly characterize SOM for the purpose of developing a model, which could be used in monitoring the effect of forest management practices on carbon uptake and storage.     

Summary of regulatory/policy/economic issues related to nitrogen

This is a summary of the two presentations from the session that dealt with the regulatory, policy and economic issues related to nitrogen compounds and the need to reduce their emissions. The papers were presented by Ronald Evans and Jan Willem Erisman. Information on ecological impacts of nitrogen species and atmospheric relationships are presented in other papers in this special issue. This summary provides an overview of the discussions from the above presentations.     

IRRIGATOR INVOLVEMENT IN THE IMPLEMENTATION OF AGRICULTURAL NONPOINT SOURCE POLLUTION CONTROL PROGRAMS1

ABSTRACT: Recently, Congress designated irrigated agriculture under the “nonpoint source” category, covered by Section 208 of P.L. 92-500 and involves the use of “best management practices.” Generally, the most appropriate solutions for pollution abatement from irrigated agriculture involve the delivery and use of water rather than the treatment of irrigation return flows. 1. Technological alternatives should be utilized that are sensitive to local conditions and acceptable to the farmers. 2. Informational and educational programs to assist farm operators individually and collectively must be instituted prior to the start of the project; imaginatively conceived, and continuously modified and upgraded if motivation for change is to be encouraged. 3. Technical assistance personnel should be given short courses in skills needed for working effectively with irrigators. 4. Communication techniques used for working with farmers as individuals and groups should be designed into the implementation program and evaluated. 5. Credibility and trustworthiness of Federal and state agencies in the eyes of the irrigators provide the important final ingredient in effectively implementing change and reducing nonpoint source pollution from irrigated agriculture.     

COMPARISON OF METHODS TO ESTIMATE DEEP PERCOLATION RATES1

ABSTRACT: Deep percolation rates are normally estimated from a water balance. Results are presented of a study undertaken to evaluate three alternative methods of estimating percolation below the root zone when knowledge about the history of applied water and evapotranspiration are not available. The alternative methods are: 1) use of Darcy's equation to calculate deep percolation rate; 2) measurement of the soil temperature prof and calculation of the deep percolation rate from the shape of the temperature depth curve; and 3) measurement of the tritium concentration in the soil water and its relationship to the history of the tritium concentration in rainfall. At the principal study site, the Darcy velocity of flow ranged from 9 cm per year determined by the temperature method, to 40 cm per year determined by the tritium method. Darcy's equation to calculate seepage rates resulted in an estimation of deep seepage of 18 cm per year. An average deep percolation rate at the principal study site of 22 cm per year was determined using the average of all three methods. Results for other sites based on the temperature method indicated a lower seepage rate.     

The National Forest and Local Agenda 21: An Experiment in Integrated Landscape Planning

The post-Rio environmental accord has offered new opportunities for landscape planning linking global concerns with Local Agenda 21 through concepts of sustainable development. This paper analyses the potential for integrated landscape planning by linking the aims of global sustainability with a major initiative of the UK Government, the National Forest located in the English Midlands. A common commitment to concepts of partnership and participation facilitated by local authorities can be found in the National Forest Strategy and in the principles of Local Agenda 21. Using case studies comparing local fora created to implement parts of the National Forest Strategy with focus groups formed to prepare Local Agenda 21 Action Plans, it is argued that a common consensus between these endeavours has not so far been achieved. Problems associated with the interpretation of national government policy guidance following the Earth Summit coupled with the constitution, membership and goals of specific groups are viewed as the primary reasons for conflict. These have implications for achieving compatibility between the Forest ideals and those enshrined in Local Agenda 21, particularly in localities where mineral exploitation and landfill are contentious planning concerns.     

Ripping Improves Tree Survival and Growth on Unused Reclaimed Mined Lands

There is renewed interest in re-establishing trees on 0.6 million ha of mining-disturbed lands in the Appalachian mountains of Eastern United States. Many coal-mined lands reclaimed to meet requirements of US federal law have thick herbaceous vegetation and compacted soils which impede tree establishment. Mitigation practices were applied on three mine sites and evaluated for success in enabling planted trees to become established. Eastern white pine (Pinus strobus), hybrid poplar (Populus deltoids × Populus trichocarpa), and mixed Appalachian hardwoods were established using weed control only and weed control with subsoil ripping. Trees were measured in October of 2008 after 5 years of growth. Subsoil ripping increased mixed hardwood survival from 43 to 71 %, hybrid poplar biomass index from 1.51 to 8.97 Mg ha^?1, and Eastern white pine biomass index from 0.10 to 0.32 Mg ha^?1. When restoring trees to unused mined sites, subsoil ripping can aid survival and growth to an extent that will result in a valuable forest.