Types Of Forest Ecosystems Research Articles

Monitoring forest biodiversity: a European perspective with reference to temperate and boreal forest zone

Recent state of forest biodiversity at the European level was reviewed and analysed with respect to the current requirements from the environmental policies as well as with respect to scientific findings in the field. The analysis reveals the main deficits and development needs, and outlines some possible courses for future action. Specific reference is given to the boreal, Atlantic and continental regions of Europe. Especially the operational definition of biodiversity, the selection of the scale and consideration of the most appropriate indicators and data collection methods are of primary importance when defining a monitoring approach. The results of a recent assessment at national scale contribute to an improved understanding, but show some shortcomings with respect to the level of detail. The high variability of the distribution, structure and composition of forests in Europe can be comprised only partially when the monitoring follows national borders. To detect changes in time for corrective measures and to be able to apply appropriate threshold values for biodiversity indicators a more detailed approach, which takes into account different bio-geographical regions and forest ecosystem types, is needed. Technically, this could be based on aggregation national forest inventories or European-wide sampling scheme combined with remote sensing data and distinct forest types or categories.

Epiphytic lichens as sentinels for heavy metal pollution at forest ecosystems (central Italy)

The results of a study using epiphytic lichens ( Parmelia caperata) as sentinels for heavy metal deposition at six selected forest ecosystems of central Italy are reported. The woods investigated are characterized by holm oak ( Quercus ilex), turkey oak ( Quercus cerris) and beech ( Fagus sylvatica) and represent the typical forest ecosystems of central Italy at low, medium and high elevations, respectively. The results showed that levels of heavy metals in lichens were relatively low and consequently no risk of heavy metal air pollution is expected for the six forest ecosystems investigated. However, for two of them there are indications of a potential risk: the beech forest of Vallombrosa showed signs of contamination by Pb as a consequence of vehicle traffic due to the rather high touristic pressure in the area, and the holm oak forest of Cala Violina showed transboundary pollution by Mn, Cr and Ni originating from the steel industry in Piombino. Epiphytic lichens proved to be very effective as an early warning system to detect signs of a changing environment at forest ecosystems.

Lepidopteran Community Response to Gypsy Moth Outbreaks is Robust to Guild Reclassification: A Reply to Summerville and Crist: Table 1.

The breadth of individual feeding guilds in ecological studies ultimately depends on the specific objectives of an experiment (Simberloff and Dayan 1991). In this sense, ecological guilds themselves can be thought of as hypotheses of community classification not unlike the way in which phylogenies are hypothesized classifications of evolutionary relationships. The strength of a given hypothesis lies in its ability to withstand reevaluation in light of alternative hypotheses. Summerville and Crist (2002) have proposed an alternative to the classification of Lepidopteran feeding guilds published by Work and McCullough (2000). Here, we reevaluate our original conclusions in light of the proposed changes of Summerville and Crist and provide evidence that these changes do not affect our overall conclusions. In addition, we address several misinterpretations made by Summerville and Crist, and comment more generally on feeding guilds and indicator value analysis. Work and McCullough (2000) compared the abundance, diversity, and species composition of adult Lepidopteran communities in replicated stands of two deciduous forest ecosystem-types that occur in northern lower Michigan. Characteristics of these ecosystems, termed ecological landtype phases (ELTP), including overstory and understory vegetation, were published as part of an ecological classification system developed for the Huron-Manistee National Forests (Cleland et al. 1993). An objective of the study involved assessing the response of the Lepidopteran community to the first gypsy moth outbreaks that occurred in this region of Michigan. One finding from this study, that a subset of oak-feeding species was negatively affected by gypsy moth defoliation, was derived from a guild classification based primarily on host plant preference. One aspect of the original analysis of Work and McCullough (2000) involved classification of 98 species, collected as adults in July or August in oak-dominated stands (defined as ELTP 20 by Cleland et al.1993), into guilds according to host-plant preference reported by …

A comparison of the watershed hydrology of coastal forested wetlands and the mountainous uplands in the Southern US

Hydrology plays a critical role in wetland development and ecosystem structure and functions. Hydrologic responses to forest management and climate change are diverse in the Southern United States due to topographic and climatic differences. This paper presents a comparison study on long-term hydrologic characteristics (long-term seasonal runoff patterns, water balances, storm flow patterns) of three watersheds in the southern US. These three watersheds represent three types of forest ecosystems commonly found in the lower Atlantic coastal plain and the Appalachian upland mountains. Compared to the warm, flat, and shallow groundwater dominated pine flatwoods on the coast, the inland upland watershed was found to have significantly higher water yield, Precipitation/Hamon's potential evapotranspiration ratio (1.9 for upland vs 1.4 and 0.9 for wetlands), and runoff/precipitation ratio (0.53±0.092 for upland vs 0.30±0.079 and 0.13±0.094 for wetlands). Streamflow from flatwoods watersheds generally are discontinuous most of the years while the upland watershed showed continuous flows in most years. Stormflow peaks in a cypress–pine flatwoods system were smaller than that in the upland watershed for most cases, but exceptions occurred under extreme wet conditions. Our study concludes that climate is the most important factor in determining the watershed water balances in the southern US. Topography effects streamflow patterns and stormflow peaks and volume, and is the key to wetland development in the southern US.

Comparative analysis of137Cs bioavailability in forest ecosystems of different type

A quantitative analysis of 137 Cs in forest soils in the long term after the Chernobyl NPP accident based on a 3 years (1996-1998) investigation is presented. Five sites with different trees composition and properties of soil were studied to identify factors determining radiocaesium transfer to trees and different under story species. The following parameters were investigated: 137 Cs activity concentrations and its speciation in various horizons of forest soil, accumulation of this radionuclide by different species of under story vegetation and distribution of their root biomass in the soil profile. It has been shown that one decade after the deposition maximum 137 Cs activity in soil of the experimental sites considered is located in different soil layers dependent on moisture regime, characteristics of litter and soil properties. High level of heterogeneity of 137 Cs specific activity in different parts of tree, which is related to physiological peculiarities of their functions, has been shown. The data obtained have demonstrated a non-uniform character for 137 Cs distribution along trunks, which can be explained by radionuclide fixation by walls of xylem vessels and by changes in geometry along the tree trunk. It has been found that the radial distribution of 137 Cs in the tree trunk is dependent on the availability of 137 Cs in soil, which governs the transfer of this radionuclide via xylem sap, and on the properties of the xylem. The accumulation of 137 Cs by both trees and under story species was influenced by 137 Cs vertical distribution and availability in soil as well as by the root (mycelia) biomass distribution in different soil horizons. A bioavailability factor, which takes into account the above factors, is proposed for comparative analyses of 137 Cs transfer from soil to plants in different types of forest ecosystems.

Patterns and processes in a seasonally flooded tropical plain: the Apure Llanos, Venezuela

AimThe factors and processes determining the ecology and distribution of ecosystems in the Apure lowlands, Venezuela, are critically discussed.LocationThe Middle Apure region, an alluvial Quaternary plain built by the Arauca and Apure rivers, occupies a subsidence area caused by faulting of the geological basement during the last and most active phases of the Andean uplift.MethodsTo assess the determinants of the hydrological and ecological variability in this region, we used remote imagery and field surveys.ResultsThe hydrological and ecological variability responds to a set of interconnected processes of different nature: geological, climatic and paleoclimatic and hydrographic, which together have conditioned the geomorphological history of the regional landscape. This evolution, in turn, has guided the soil forming processes and the functional behaviour of the different types of savanna, forest and wetland ecosystems. The continuously subsiding trend of the Llanos that accompanied the Andean Orogeny, together with the Quaternary climatic oscillations, settled the framework in which successive depositional and erosional events took place. Five Quaternary depositional events, gave rise to the actual landscape pattern. The youngest, Q0a is the actual flood plain, Q0b is the Holocene flood plain, Q1 is from Upper Pleistocene, Q2 from Middle Pleistocene, while Q3 the oldest sedimentary material in this area, is of Lower Pleistocene age. Within each sedimentary unit, we analysed the pattern of land forms, soils and natural ecosystems. The Q0 and Q1 land units show a characteristic unstable drainage system, with frequent changes in the course of rivers and their affluents and diffluents. Soil genesis mainly correlates with the contrasting characteristics of the wet and dry tropical climate, and with the water regime of each land form on each sedimentary unit. So, a sequence from entisols, through inceptisols and alfisols, to ultisols, correlates with the sequence of land units from Q0 to Q3. Different vegetation types predominate on each land form/soil unit. Gallery forest (evergreen and semi‐evergreen) exclusively occurs on Q0a entisols, semi‐deciduous forest characterizes Q0b and Q1 inceptisols, semi‐seasonal savanna is almost entirely restricted to Q0 and Q1 units, hyperseasonal savanna widely dominates on Q2 and Q3 alfisols and ultisols, while seasonal savanna just occurs on the well‐drained Q1 and Q2 alfisols, and on dunes.Main conclusionsThe genesis and dynamics of the various land forms and soils throughout the Quaternary, provide the key to their particular hydrology, and determines the kind of plant formation able to occupy each habitat, thus explaining the complex pattern of quite different ecosystems found in the region.

Identification of processes governing long-term accumulation of 137Cs by forest trees following the Chernobyl accident.

The regularities of 137Cs distribution in trees (Pinus sylvestris and Betula pendula) growing in different types of forest ecosystems were investigated. High levels of heterogeneity of 137Cs activity concentrations in different parts of the trees, resulting from their varied metabolism have been shown. The data obtained demonstrate a non-uniform character of 137Cs distribution along the trunks, which can be explained by radionuclide fixation by the xylem vessel walls and by geometry changes along the tree trunk. It has been found that the radial distribution of 137Cs in the tree trunk is dependent on the availability of 137Cs in soil, which governs the transfer of this radionuclide via xylem sap and on the properties of the xylem. The accumulation of 137Cs by trees was influenced by the vertical distribution and availability of 137Cs in the soil as well as by the root biomass distribution in different soil horizons. A bioavailability factor, which takes into account the vertical distribution of radiocesium in soil, bioavailability of this radionuclide and distribution of root biomass in different soil horizons is proposed for comparative analyses of 137Cs transfer from soil to trees in different types of forest ecosystems.

137Cs availability for soil to understory transfer in different types of forest ecosystems

A quantitative analysis of 137Cs bioavailability in forest soils in the long term after the Chernobyl NPP accident based on a 3-year (1996–1998) investigation is presented. Five forest sites with different trees, composition and properties of soil were studied to identify factors determining radiocaesium transfer to different understory species. The following parameters were investigated: 137Cs activity concentrations and its speciation in various horizons of forest soil, accumulation of this radionuclide by different species of understory vegetation and distribution of root biomass in the soil profile. It has been shown that one decade after the deposition maximum 137Cs activity in soil of the experimental sites considered is located in different soil layers dependent on moisture regime, characteristics of litter and soil properties. A linear dependence between aggregated transfer factors for different species and groups of species of understory vegetation and exchangeable and available fractions of radiocaesium in soil was found. The vertical distribution of 137Cs activity, percentage of exchangeable radiocaesium in each horizon of litter and soil, as well as distribution of root systems (mycelia) over the soil profile are key factors governing variations in the availability of 137Cs for transfer to all forest understory components.

Valuing ecological functions of biodiversity in Changbaishan Mountain Biosphere Reserve in Northeast China

Conservation of biodiversity can generate considerable indirect economic value and this is being increasingly recognized in China. For a forest ecosystem type of a nature reserve, the most important of its values are its ecological functions which provide human beings and other living things with beneficial environmental services. These services include water conservancy, soil protection, CO2 fixation and O2 release, nutrient cycling, pollutant decomposition, and disease and pest control. Based on a case study in Changbaishan Mountain Biosphere Reserve in Northeast China, this paper provides a monetary valuation of these services by using opportunity cost and alternative cost methods. Using such an approach, this reserve is valued at 510.11 million yuan (USD 61.68 mill.) per year, 10 times higher than the opportunity cost (51.78 mill. yuan/ha.a) for regular timber production. While China has heeded United Nations Environmental Program (UNEP)'s call for economic evaluation of ecological functions, the assessment techniques used need to be improved in China and in the West for reasons mentioned.

The biodiversity and dynamics of oribatid mites in rice paddies

Species abundance, biodiversity, distribution and population dynamics within and among oribatid mite communities were studied in rice paddies of China from October 1995 to November 1996. The Shannon-Wiener Index of Diversity and the Evenness Index indicated that the abundance and diversity of oribatids in rice paddies varied among locations and was lower than that of a typical forest ecosystem. The ability to resist environmental disturbance was low in the oribatid communities in sub-tropical monsoon areas and was more stable in monsoon temperate zones. The relative proportion of higher oribatid mites to lower oribatid mites in rice paddies is higher than that of other communities. The oribatid mites in paddy fields were mainly distributed in the upper layers of soil, which is similar to the distribution in the forest ecosystem, but the ability to distribute horizontally indicated their tendency to migrate freely within these layers. Water was an important factor allowing oribatid mites to migrate freely. The spatial distribution on rice plants indicated that mites were aggregated except there was a more even distribution in the later stages of rice maturity. Humidity and temperature, which are known to significantly affect oribatid communities in other habitats, did not significantly influence community structure on rice plants. The oribatid communities on rice was strongly affected by both mite migration and dispersion.

Improvement of tropical vegetation mapping using a remote sensing technique: A case of Khao Yai National Park, Thailand

The forest ecosystems of Thailand are characterized by a diverse and complex vegetation structure. Classification of vegetation types of such forest ecosystems has been experienced as a difficult task, even with large-scale aerial photography. Satellite remote sensing, the digital technique in particular, has not been widely used for vegetation mapping in Thailand until now. The objective of this study was to explore the potential of digital image processing over the existing technique of visual interpretation of Landsat Thematic Mapper (TM) false colour composite (BGR-2, 3, 4) to produce forest cover maps in Thailand. Supervised and unsupervised classification methods were employed with different band combinations to discriminate vegetation types in the Khao Yai National Park using Landsat TM data. The results indicated that thematic classes derived from supervised classification produced higher overall accuracy than unsupervised classification. In addition, the combination of ratio bands R4/3, R5/2, R5/4 and R5/7 ranked the highest in terms of accuracy (65% for unsupervised and 79% for supervised) and the combination of bands 2, 3 and 4 gave the lowest (56% for both methods). Finally, it was concluded that, even within the limit of spectral information available in the image, the digital classification can improve the result of visual interpretation.

Site variation in methane oxidation as affected by atmospheric deposition and type of temperate forest ecosystem

Factors controlling methane oxidation were analyzed along a soil acidity gradient (pH(H2O) 3.9 to 5.2) under beech and spruce forests in Germany. Mean annual methane oxidation ranged from 0.1 to 2.5 kg CH4 ha−1 yr−1 and was correlated with base saturation (r2 = 0.88), soil pH (r2 = 0.77), total nitrogen (r2 = 0.71), amount of the organic surface horizon (r2 = 0.49) and bulk density of the mineral soil (r2 = 0.43). At lower pHs the formation of an organic surface horizon was promoted. This horizon did not have any methane oxidation capacity and acted like a gas diffusion barrier, which decreased the methane oxidation capacity of the soil. In contrast, on sites at the higher end of the pH range, higher burrowing activity of earthworms increased macroporosity and thereby gas diffusivity and methane oxidation. Gas diffusivity was also affected by litter shape: broad beech leaves reduced methane oxidation more than spruce needles. An increase in methane oxidation of most soil samples following sieving indicates that diffusion is the main limiting factor for methane oxidation. However, this “sieving effect” was less in soils with a pH below 5 than in soils with a pH above 5, which we attribute to a direct effect of soil acidity. We discuss our results using a hierarchical concept for the “short‐term” and “long‐term” controls on methane oxidation in forest ecosystems.

Increased atmospheric CO2 and litter quality

There is evidence that N concentration in hardwood leaf litter is reduced when plants are raised in an elevated CO2 atmosphere. Reductions in the N concentration of leaf litter have been found for tree species raised under elevated CO2, with reduction in N concentration ranging from ca. 50% for sweet chestnut (Castanea sativa) to 19% for sycamore (Acer platanoides). However, the effects of elevated CO2 on the chemical composition of litter has been investigated only for a limited number of species. There is also little information on the effects of increased CO2 on the quality of root tissues. If we consider, for example, two important European forest ecosystem types, the dominant species investigated for chemical changes are just a few. Thus, there are whole terrestrial ecosystems in which not a single species has been investigated, meaning that the observed effects of a raised CO2 level on plant litter actually has a large error source. Few reports present data on the effects of elevated CO2 on litter nutrients other than N, which limits our ability to predict the effects of elevated CO2 on litter quality and thus on its decomposability. In litter decomposition three separate steps are seen: (i) the initial stages, (ii) the later stages, and (iii) the final stages. The concept of "substrate quality," translated into chemical composition, will thus change between early stages of decomposition and later ones, with a balanced proportion of nutrients (e.g., N, P, S) being required in the early decomposition phase. In the later stages decomposition rates are ruled by lignin degradation and that process is regulated by the availability of certain nutrients (e.g., N, Mn), which act as signals to the lignin-degrading soil microflora. In the final stages the decomposition comes to a stop or may reach an extremely low decomposition rate, so low that asymptotic decomposition values may be estimated and negatively related to N concentrations. Studies on the effects of changes in chemical composition on the decomposability of litter have mainly been made during the early decomposition stages and they generally report decreased litter quality (e.g., increased C/N ratio), resulting in lower decomposition rates for litter raised under elevated CO2 as compared with control litter. No reports are found relating chemical changes induced by elevated CO2 to litter mass-loss rates in late stages. By most definitions, at these stages litter has turned into humus, and many studies demonstrated that a raising of the N level may suppress humus decomposition rate. It is thus reasonable to speculate that a decrease in N levels in humus would accelerate decomposition and allow it to proceed further. There are no experimental data on the long-term effect of elevated CO2 levels, and a decrease in the storage of humus and nutrients could be predicted, at least in temperate and boreal forest systems. Future works on the effects of elevated CO2 on litter quality need to include studies of a larger number of nutrients and chemical components, and to cover different stages of decomposition. Additionally, the response of plant litter quality to elevated CO2 needs to be investigated under field conditions and at the community level, where possible shifts in community composition (i.e., C3 versus C4 ; N2 fixers versus nonfixers) predicted under elevated CO2 are taken into account.Key words: climate change, substrate quality, carbon dioxide, plant litter, chemical composition, decomposition.

Simulation of landscape pattern of old growth forests of Korean pine by block kriging

The study area was located in Liangshui Natural Reserve. Xaoxing’an Mountains. Northeastern China Korean pine forests are the typical forest ecosystem and landscapes in this region. It is a high degrees of spatial and temporal heterogeneity at different scales, which effected on landscape pattern and processes. In this paper we used the data of 144 plots and semivariogram to analyze spatial heterogeneity of old growth forests of Korean pine in landscape level. Model for forest variations by isotropic semivariogram is linear with sill. The spatial heterogeneity is dependent on scales and directions in Korean pine forests. Patterns of forest types in space were resulted from complex interactions between physical and biological forces. We used 20 metres for interpolation interval to estimate the values of unsampled area. Comparing the results with field data, block kriging and mapping are an effective techniques to simulate landscape pattern.

Forest ecosystems of the Marietta Unit, Wayne National Forest, southeastern Ohio: multifactor classification and analysis

Local forest ecosystem types were identified using an iterative approach consisting of reconnaissance, plot sampling, and multivariate data analysis. Canonical correspondence analysis (CCA) indicated that aspect and other environmental variables were highly correlated with the ground flora and canopy tree species. A multifactor classification comprising 10 ecological land type phases (ELTPs) was based on cluster analysis of the six most important physiographic and edaphic factors. The characteristic vegetation of each ELTP was specified by distinctive groups of mature canopy trees and of ground flora species identified by two-way indicator species analysis. Within this unglaciated area of southeastern Ohio, the majority of the landscape comprises moderately to steeply sloping terrain. Quercus dominated dry and dry-mesic ridgetops and slopes, while Liriodendron tulipiferaL. and Acer saccharumMarsh. dominated mesic slopes and wet-mesic ravine bottoms. In general, many of the 17 ecological species groups of ground flora plants were more closely related to the major environmental gradients than were six groups of canopy tree species. Multiple-response permutation procedures were used to corroborate the differences in these two vegetation layers among ELTPs. This classification system was developed to provide an ecological framework as the basis for ecosystem management on the Wayne National Forest. Resume : Des types d'ecosysteme forestier local ont ete identifies a l'aide d'une approche iterative comportant une reconnaissance, un echantillonnage par parcelles et une analyse multivariee des donnees. L'analyse canonique des correspondances a montre que l'exposition et d'autres variables environnementales etaient fortement correlees avec la flore

Forest mapping from multi‐source satellite data using neural network classifiers—an experiment in Portugal

Abstract The monitoring of forest ecosystems and their biodiversity is a major challenge for satellite remote sensing. The opportunity now exists for operationally using multi‐sensor high resolution satellite data from optical, infrared and microwave parts of the electromagnetic spectrum. An experiment is reported on the integrated use of Landsat Thematic Mapper (TM) imagery combined with ERS‐1 Synthetic Aperture Radar (SAR) imagery for mapping eight identifiable types of forest ecosystem in a test area of approximately 100 x 100 km in western central Portugal. The TM and SAR images were geometrically co‐registered and resampled to a spatial resolution of 25 m. The SAR data were despeckled using a multiple regression method based on the TM scene. The classification of the integrated multi‐sensor dataset was carried out using multi‐layer perceptron neural networks which were trained using ground truth samples taken from test sites within the experimental area. The neural network was used in two separate mapping stages: the first to map nine basic classes of land cover including one of forest, and the second to map eight different types of forest within the generic forest land cover area. The total classification accuracy achieved for the eight forest classes was 77.7% from the integrated TM and SAR dataset, which was 1.7% higher than the accuracy achieved using the TM data alone. Whilst the overall classification accuracy did not improve significantly through the use of SAR data in addition to TM, there were some significant gains for certain individual classes. In particular, the addition of the SAR channel gave a 13.1% improvement in the discrimination of a mixed conifer/broad‐leaf class largely by giving better separation from a pure conifer class.

Nitrous oxide flux and nitrogen transformations across a landscape gradient in Amazonia

Nitrous oxide flux and nitrogen turnover were measured in three types of Amazonian forest ecosystems within Reserva Florestal Ducke near Manaus, Brazil. Nitrogen mineralization and nitrate production measured during 10‐day laboratory incubations were 3–4 times higher in clay soils associated with “terra firme” forests on ridge‐top and slope positions than in “campinarana” forests on bottomland sand soils. In contrast, nitrous oxide fluxes did not differ significantly among sites, but were highly variable in space and time. The observed frequency distribution of flux was positively skewed, with a mean over all sites and all sampling times of 1.3 ng N2O‐N cm−2h−1. Overall, our flux estimates were comparable to or greater than those of temperate forests, but less than others reported for Amazonia. Results from a field fertilization experiment suggest that most nitrous oxide flux was associated with denitrification of soil nitrate.

Changes in the weight and nutrient composition of litter fall in three forest ecosystem types on coastal British Columbia

Changes in weight and nutrient concentrations (N, P, K, Ca, Mg) of foliage and twig litter fall were measured over an 18-month period at three positions along a topographic sequence of ecosystem types. Conifer foliage confined in litter bags was found to lose weight at the same rate on all three sites: about 35% after 12 and 40% after 18 months. Confined broadleaf foliage decomposed at about the same rates on all sites, but unconfined samples decomposed significantly faster on the lower, hygric sites, probably as a result of greater fragmentation losses. Twig weight loss of conifers was extremely variable, ranging from 10 to 28% after 12 months. The total mass of K, Mg, and Ca decreased over the study period in all foliage litter, while N increased and P was variable. K tended to be more mobile on the hygric sites. Ca was found to be the most rapidly lost element in almost all cases. It was concluded that the observed similarity in weight loss of conifer foliage on all sites is partially due to a confinement effect and partially to a substrate chemistry effect. The nutrient data suggest that there may be some differences in decomposition processes on the lower, hygric sites compared with other ecosystem types. This agrees with the observation that the humus form in the hygric site is different (duff mull) from that on the other two sites (felty mor).

Effect of Chronic Gamma Radiation on Parmelia subaurifera in the Enterprise Radiation Forest

In the Enterprise, Wisconsin, Radiation Forest thalli of Parmelia subaurifera Nyl. received varying doses of gamma radiation (137Cs) during the summer of 1972. Thalli which received 122,272 r exhibited radiation damage by the end of the radiation period. The damage was seen in the decrease of thalloid algal cells, bleaching of the thallus, upper cortex breakup and, eventually, the disappearance of the thallus. Thalli receiving 78,797 r initially exhibited temporary damage in the destruction of some algal cells and cessation of thallus growth. By 1973 algal cells appeared normal and by 1974 growth had resumed. No damage was seen in thalli which had received 66,570 r or less. The North Central Forest Experiment Station, at Rhinelander, Wisconsin, began a study in 1969 on the effects of gamma radiation in typical northern forest ecosystems (the Enterprise, Wisconsin, Radiation Forest). In 1972 a 10,000 Ci 137Cs radiation source was placed into operation. The forest ecosystems were irradiated 20 h/day for a total of 166 days and 2717 h. For more detail on the radiation site and preirradiation studies see Rudolph (1974) and for the results of the radiation studies see Zavitkovski (1977). This radiation site provided an opportunity to study the effects of gamma radiation on lichens in their natural habitat. When the study was initiated only two published studies were found which dealt with gamma radiation and lichens in natural habitats. One by Brodo (1964) indicated that the lichen flora was affected more by microclimate changes than radiation damage; whereas Woodwell and Gannutz (1967) indicated that gamma radiation had a greater effect on lichens than environmental conditions. The study undertaken in the Enterprise Radiation Forest was designed to consider both ecological and radiological effects on lichens. After examining the lichen flora in the radiation site, Parmelia sulcata was chosen as the primary study organism because it was found throughout the radiation and control areas (cf. Erbisch, 1974, 1977). Parmelia subaurifera Nyl. occurred on many of the same tree sites with P. sulcata; consequently it was also examined to determine the effects of both gamma radiation and environmental change. 'The work reported here was supported by the U.S. Energy Research and Development Administration under contract E(11-1)-2085. Appreciation is expressed for the assistance received from the personnel of the North Central Forest Experiment Station, Rhinelander, Wisconsin, especially Dr. J. Zavitkovski. I wish to thank E. M. Erbisch for her assistance in this project. 2 Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931. 0007-2745/78/137-143$0.95/0 This content downloaded from 207.46.13.158 on Sun, 10 Apr 2016 06:23:03 UTC All use subject to http://about.jstor.org/terms 138 THE BRYOLOGIST [Volume 81 TABLE 1. Location and radiation data for the Parmelia subaurifera Nyl. thalli on Acer rubrum studied in the Enterprise Radiation Forest.