Forest Health Assessment and Monitoring – Issues for Consideration

Part of this paper has been prepared for the lecture Forest Health Assessment-Criteria,Methods and Problems given by the author at the UIMPuniversity course Sanidad Forestal en el Bosques Mediterraneos yTemplados. Implicacion de la Contaminacion Atmosferica y del Cambio Global, held in Valencia, Spain, October, 1995. Assessment and monitoring of forest health representsa key point for environmental policy and for the management ofenvironmental resources. With the renewed interest in assessment andmonitoring of forest health generated by the suspected occurrence ofa widespread forest decline in Europe and North America, manyactivities have been undertaken: however, some questions should beconsidered and clarified when attempting to estimate forest health.Particularly, the objective(s) of the assessment and monitoringprogram should be carefully identified. Identification of a program‘stask has a number of implications and consequences: it implies adefinition of what concept of forest health (forest ecosystem health,forest health or forest trees health?) is assumed, what will be thetarget entity to be monitored, and therefore the identification of therelevant assessment questions and assessment endpoints.Consequences concern the definition of the spatial scale (frominternational to landscape and plot scale monitoring) and ecologicalcoverage (from single species population to population ofecosystems) of the program, which can have a considerable influenceon the choice of the proper sampling strategy and tactic, as well ason the most suitable methods, indicators and indices to be used.Although much of the work in the field of forest health and airpollution has concentrated on surveys on crown transparency anddiscoloration, there is an entire range of methods, indicators andindices developed to assess the health status of forests. The decisionas to which ones should be used will depend on the aim of theprogram and on economic and practical considerations. A furtherconsideration concerns the time span of the program, but anydecision in this field is subject to many limitations due to difficultiesin predicting future monitoring needs. All these points should becarefully considered and implemented according to a rigorousQuality Assurance procedure since any decision will influence futurework for many years.     

Integrating disciplinary research into an interdisciplinary framework: A case study in sustainability research

The complexity of today’s research problems increasingly demands that scientists move beyond the confines of their own discipline. In this special issue, the basics of a transdisciplinary framework are established and problems analyzed in a specific discipline are successfully integrated in this transdisciplinary network. The intent has been to go beyond only statements about the importance of enabling early stage researchers to work across disciplinary boundaries, and to show that important discoveries are being made at the intersection of disciplines. Embedding various research projects in a more global framework can meet the demands of an interdisciplinary or transdisciplinary approach (especially for early stage researchers) and contribute significantly to sustainable research.     

A study on the orbit of air temperature movement

In this paper, we describe an air temperature movement by mapping its time series to the polar coordinates: the value of the time series is plotted on the radial coordinate and the time on the angular coordinate. In this way, both the yearly and daily air temperature movements from five different locations of China are used to demonstrate that, in an intuitionistic view, air temperature movement is neither random nor chaotic, but has its own orbit. We then propose an elliptic orbit model for the air temperature movement. Our proposed model provides quite good results when it is applied to the evaluation of yearly air temperature movements in eight locations in various parts of the world, and the evaluation of daily air temperature movements in five locations in Hunan Province of China on December 17, 2005. Results show that our approach provides a concise and helpful model for air temperature analysis.     

Documentation of cumulative impacts in environmental impact statements

The National Environmental Policy Act (NEPA) of 1969 and the Council on Environmental Quality (CEQ) regulations in the United States require federal agencies to apply an environmental impact assessment (EIA) in decision-making related to their actions. One aspect requires an examination of direct, indirect and cumulative impacts (CIs). Historically, cumulative impact assessment (CIA) has been given limited attention in EIA and resultant environmental impact statements (EISs), not because of its lack of importance, but owing to limitations in methodologies and procedures, including documentation consistency. The objectives of this study were to identify deficiencies in the documentation of CIs and CIA in EISs and to formulate appropriate recommendations (potential solutions) related to such deficiencies. The study involved the systematic review of 33 EISs (11 each from the U.S. Department of Agriculture: Forest Service, the U.S. Army Corps of Engineers, and the U.S. Department of Transportation: Federal Highway Administration). The results indicate that improvements have been made in documentation practices since 1990; however, inconsistencies and inadequacies still exist. Therefore, the following recommendations were developed: (1) CIs should be reported in a separate part of the “Environmental Consequences” section, and they should be addressed for each pertinent environmental resource; (2) a summary of CIs should be included; (3) any CIs considered not significant should be mentioned plus the reason(s) for their non-significance; (4) spatial and temporal boundaries addressed within the CIA process should be defined for pertinent environmental resources; and (5) utilized guidelines and methodologies should be described.     

Overstory mortality as an indicator of forest health in California

The interagency Forest Health Monitoring Program involves a network of about 4200 forest plots on a triangular grid across the United States. We present data on recent mortality of trees 27.9 cm diameter from the first three years of measurements in California (1992–1994). Three plot designs were used to collect data representative of a 1-ha stand at each site; the designs differed primarily in total area sampled (0.067, 0.4 and 1.0 ha). Approximately 50 sites were visited each year yielding a total of about 150. Field tallies showed few cases of recent mortality in the smallest plot size. Cumulative distribution functions of recent dead tree densities in the 0.067-ha plots differed significantly from those generated by tallies from entire 1-ha stands. We conclude that an area of 0.067 ha is unsuitable to assess and monitor overstory mortality in Pacific Coast forests.The U.S. government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.     

Techniques and methods for the determination of haloacetic acids in potable water

Haloethanoic (haloacetic) acids (HAAs) are formed as disinfection byproducts (DBPs) during the chlorination of natural water to make it fit for consumption. Sundry analytical techniques have been applied in order to determine the concentrations of the HAAs in potable water supplies: gas chromatography (GC-MS, GC-ECD); capillary electrophoresis (CE); liquid chromatography (LC), including ion chromatography (IC); and electrospray ionization mass spectrometry (ESI-MS). Detection limits required to analyze potable water samples can be regularly achieved only by GC-ECD and ESI-MS. Without improvements in preconcentration or detector sensitivity, CE and LC will not find application to potable water supplies. The predominant GC-ECD methods use either diazomethane or acidified methanol to esterify (methylate) the carboxylic acid moiety. For HAA5 analytes, regulated under the EPA's Stage 1 DBP Rule, diazomethane is satisfactory. For HAA9 data gathered under the Information Collection Rule, acidified methanol outperforms diazomethane, which suffers from photo-promoted side reactions, especially for the brominated trihaloacetic acids. Although ESI-MS can meet sensitivity and selectivity requirements, limited instrumentation availability means this technique will not be widely used for the time being. However, ESI-MS can provide valuable confirmatory information when coupled with GC-ECD in a research setting.     

Temporal variation in a coral reef community at Pattaya Bay,Gulf of Thailand

Changes in the fringing coral reef community of a small island (Ko Nok) at Pattaya Bay, Gulf of Thailand, were examined at the beginning and at the end of a 3-year period using 7m×7m permanent quadrats for benthic organisms, and visual census along 100m transects for fish. The coral community was dominated by Porites lutea in terms of colony number and areal cover throughout the period. Variations in the community structure parameters on opposite sides of the island indicated increasing dissimilarity with time. Little variation in live coral cover was noted, but colony number and species diversity declined on both sides. The abundance of edible fish species dropped while that of non-edible species increased over the 3-year period, indicating selective removal of the former category through fishing. Impacts from both human and natural influences are implicated in these changes.     

Excrement from Heron colonies for environmental assessment of toxic elements

Excrement cast from Great Blue Heron nests was collected during the nesting period of 1978 from four colonies in Washington and Idaho. Cheesecloth strips placed on the ground beneath the nests served as excrement collecting devices. Chemical analysis for lead, mercury and cadmium were performed on dried samples. Lead was the most abundant trace metal found in heron debris. The Idaho colony at Lake Chatcolet had an average concentration of 46 ppm in the beneath-nest samples and 6 ppm in control samples. A heron colony near Tacoma, Washington had beneath-nest samples averaging 28 ppm and control samples averaging 20 ppm. Two colonies located in the interior region of Washington had substantially lower concentrations of lead. The difference observed between colonies was attributed to their associations with a polluted watershed (Chatcolet colony) an interstate highway (Tacoma colony) and an unpopulated largely agricultural area (inland Washington).     

Field scale variability of cadmium and zinc in soil and barley

CaCl₂-extractable soil Cd and Zn contents have been suggested as a measure of bioavailability. To investigate the ability of this measure to reflect spatial patterns of Cd and Zn concentrations in barley (Hordeum vulgare L.) in an arable field, plant and soil samples were taken from a 0.5 ha area sandy soil contaminated with Cd and Zn. Cd and Zn contents in barley and yield were spatially variable. Yield was low, which may have been caused by Zn toxicity or atrazine turnover. For Cd, CaCl₂-extractable soil contents explained only 17% of the variation in Cd contents in grain, and for Zn no significant correlation was observed. Nevertheless, surface plots of CaCl₂-extractable soil contents and contents of barley grain illustrated their corresponding spatial patterns. Despite the poor linear correlation between CaCl₂-extractable soil-Cd and grain-Cd, a stochastic model for long term behaviour of Cd in field soils predicted observed variability in Cd contents of barley grain well from spatial variability of soil pH and organic matter content. The probabilistic model predicted behaviour of Cd in terms of probability, and was more appropriate than the deterministic approach.