Integrated Management to Create New Breeding Habitat for Dalmatian Pelicans (Pelecanus crispus) in Greece

/ An integrated management plan to create favorable nesting habitat for the world-endangered Dalmatian pelicans, was tested at Kerkini irrigation reservoir, a Ramsar wetland. The lake is the major wintering site of Dalmatian pelicans in Europe, where the species lives year-round without breeding. The rise of water level at the reservoir during spring (exceeding 5 m) has an impact on the whole system, including several birds, which lose their nesting habitat. Although the integrity of the wetland demands ecological restoration with changes in its hydrologic regime, local socioeconomic conditions allow only habitat level interventions. During the planning phase of the management plan, both the ecological and social context of the interventions were considered. Monitoring of all pelican habitats and populations provided the scientific basis, while a socioecological survey on knowledge/attitudes of local fishermen toward wetland identified conflicts with specific resources and planned management. To gain public support, a broad information/education program was implemented. The education program for fishermen was based on the findings of the socioecological survey. The in situ management involved experimental construction of floating rafts, platforms over water, dredged-spoil islands, and platforms at various sites of the wetland. Monitoring of the managed habitats showed that most waterbirds used them for resting and roosting. Common terns nested on the rafts, cormorants on the platforms, and Dalmatian pelicans on the man-made island. Under the prevailing hydrologic and weather conditions, islands seem to be the most suitable habitat for pelican nesting. It is concluded that wildlife habitat management should integrate the ecological component, related to the needs of the species and ecosystem, with the social one, expressed by cooperation and involvement of the local community.KEY WORDS: Integrated management; Pelican; Nesting habitat; Habitat management; Reservoir-wetland; Public participation, Greece     

Rough Set Rule Induction for Suitability Assessment

The data that characterize an environmental system are a fundamental part of an environmental decision-support system. However, obtaining complete and consistent data sets for regional studies can be difficult. Data sets are often available only for small study areas within the region, whereas the data themselves contain uncertainty because of system complexity, differences in methodology, or data collection errors. This paper presents rough-set rule induction as one way to deal with data uncertainty while creating predictive if–then rules that generalize data values to the entire region. The approach is illustrated by determining the crop suitability of 14 crops for the agricultural soils of the Willamette River Basin, Oregon, USA. To implement this method, environmental and crop yield data were spatially related to individual soil units, forming the examples needed for the rule induction process. Next, four learning algorithms were defined by using different subsets of environmental attributes. ROSETTA, a software system for rough set analysis, was then used to generate rules using each algorithm. Cross-validation analysis showed that all crops had at least one algorithm with an accuracy rate greater than 68%. After selecting a preferred algorithm, the induced classifier was used to predict the crop suitability of each crop for the unclassified soils. The results suggest that rough set rule induction is a useful method for data generalization and suitability analysis.     

Decline in Endangered Species as an Indication of Anthropic Pressures: The Case of European Mink Mustela lutreola Western Population

Populations of threatened species, especially predators at the top of the food chain, may be affected by anthropic pressures. The endangered western population of European mink Mustela lutreola has shown a large decline over 50% of its natural range. M. lutreola disappeared from northwestern France between 1984 and 1997, and the decline was associated with an increase in mustelid trapping, changes in watercourse quality, and habitat modifications due to agricultural practices. The pattern of decline showed a fragmentation restricting the minks into very small areas. Trapping was the first known cause of mortality. Although feral American mink Mustela vison may compete with autochthonous carnivores, M. lutreola had disappeared from streams before the introduction of the American species, suggesting that competitive interactions were not responsible. Furthermore, American mink has never been found or has remained rare in 62.4% of the area from which M. lutreola has disappeared. During the past 25 years, permanent grassland surfaces were reduced by 40%, whereas fodder culture increased by 470%, causing considerable habitat changes. Furthermore, 55.7% of water courses were classified as being of bad quality or polluted. Therefore, our data suggests that a conjunction of intensive trapping, alterations in water quality and habitat modification was critical for the European mink's decline. Although there are difficulties in ascribing specific cause to distribution changes in a top predator, this decline can be regarded as an indication for anthropic pressures on natural habitats.     

Using Satellite Imagery to Assess Large-Scale Habitat Characteristics of Adirondack Park, New York, USA

Satellite imagery is a useful tool for large-scale habitat analysis; however, its limitations need to be tested. We tested these limitations by varying the methods of a habitat evaluation for white-tailed deer (Odocoileus virginianus) in the Adirondack Park, New York, USA, utilizing harvest data to create and validate the assessment models. We used two classified images, one with a large minimum mapping unit but high accuracy and one with no minimum mapping unit but slightly lower accuracy, to test the sensitivity of the evaluation to these differences. We tested the utility of two methods of assessment, habitat suitability index modeling, and pattern recognition modeling. We varied the scale at which the models were applied by using five separate sizes of analysis windows. Results showed that the presence of a large minimum mapping unit eliminates important details of the habitat. Window size is relatively unimportant if the data are averaged to a large resolution (i.e., township), but if the data are used at the smaller resolution, then the window size is an important consideration. In the Adirondacks, the proportion of hardwood and softwood in an area is most important to the spatial dynamics of deer populations. The low occurrence of open area in all parts of the park either limits the effect of this cover type on the population or limits our ability to detect the effect. The arrangement and interspersion of cover types were not significant to deer populations.     

基于驾驶适宜性检测的沙漠公路驾驶员视觉特性分析

利用动体视力检测仪,对沙漠公路行车途中汽车驾驶员进行包括静视力和动体视力在内的视觉特性的实地测试,并就获得的1004个有效样本的检测数据进行统计整理,对受测驾驶员静、动体视力总体情况及其与驾驶员年龄、驾龄、持续行车时间、检测时的气温等因素之间的关系进行分析研究。对驾驶员视觉特性的实测分析表明:沙漠公路受测驾驶员静视力和动体视力平均值分别为1.3和0.7;动体视力相对于静视力的平均下降幅度为44.75%,远高于绿洲地区。关联度分析也表明,驾驶员的年龄、驾龄、驾车时间以及测试温度4项因素对其静视力、动视力以及视力降幅均具有较强的相关性,关联度均在0.76以上。     

A land suitability model for the evaluation of land-use change

A land suitability model was developed to provide the planner with a quantitative tool for assessing the environmental limitations on proposed land-use changes in the area surrounding Lake Monroe in southern Indiana. The model incorporates a weighting procedure that allows the environmental evaluation of a decision to convert the present land use to another category. The data base for the model was assembled by a multidisciplinary team. A case study is included, which illustrates the advantages and limitations of the land suitability model as it is applied to the evaluation of a site for the Alumni Family Camp.     

EXPERIMENTAL DREDGING TO CONVERT LAKE BOTTOM FROM ABIOTIC MUCK TO PRODUCTIVE SAND1

ABSTRACT: Conversion of muck to sand bottom was tested to increase benthic production in two eutrophic Florida lakes, and preliminary results indicate that benthos will be increased in areas converted to sand. Muck removal with a specially designed dredge, or “Mudcat,” was tested in Trout Lake. The Mudcat removed 41,650 cu. yds. of muck and exposed 17 acres of sand bottom, but 10 of those acres developed thin layers of muck, which proved too soft to be picked up by the Mudcat. Consequently, only 7 acres were satisfactorily converted. Bottom redistribution with a suction-type dredge was tested in Lake Carlton, and 14 acres were converted from muck to sand. Sand covered with muck was pumped from midlake areas to more peripheral areas of the lake where water depths were 11 to 13 feet and muck layer about 1.5 feet deep. The bottom was built up to an elevation above the previous muck elevation. Several methods for depositing the sand were tested. Level areas of sand fill developed accumulations of muck from fallout following dredging activity. Piles or dunes provided the best cost-return ratio. The bottom in filled areas changed very little during a 1½ year period following filling.     

The habitat saturation hypothesis and sociality in an allodapine bee: cooperative nesting is not “making the best of a bad situation”

Several factors thought to be important for the evolution of cooperative breeding in vertebrates have received little attention in facultatively social insects. One of these, the “habitat saturation hypothesis” of Selander (1964), predicts that colony sizes will be greater in breeding units where dispersal opportunities are limited, suggesting that group living is a secondary option to independent reproduction. The Australian allodapine bee Exoneura bicolor exhibits a number of traits that occur in cooperatively breeding bird species, including long life-span, repeated opportunities for reproduction, and vulnerability to brood predation and parasitism. We experimentally examined the effect of a potentially limiting environmental factor, nesting substrate availability, as an agent influencing sociality in E. bicolor. We manipulated nesting substrate availability in two separate locations during a time when foundress dispersal is common. No significant difference was found between colony sizes in cases where dispersal options were abundant and cases where dispersal options were limited. An increase in opportunities for dispersal did not lead to higher rates of independent nesting, suggesting that cooperative nesting is a preferred strategy regardless of distance-related costs of dispersal. Reproductivity per female and brood survival were examined as factors selecting for group living. Low survival of brood in single-female nests has the potential to select for cooperative nesting in this bee. Received: 29 September 1995/Accepted after revision: 24 June 1996     

中国省域城市生态适宜度综合评价

依据城市生态系统原理,从生产位、生活位、环境位3方面构建了综合衡量城市生态适宜度的指标体系和数学方法,以各个省区地级以上城市作为分析样本,通过对评价区的各领域以及生态适宜度水平综合评价,结果表明:中国省域城市生态适宜度具有的明显区域性差异,城市生态适宜度大致呈现:东部高、中西部低,南方高、北方低的格局,既与区域自然生态条件有关,也同地方社会经济发展、城市建设与管理水平相关。     

Echolocation behavior of the bat <Emphasis Type="Italic">Vespertilio murinus</Emphasis> reveals the border between the habitat types “edge” and “open space”

We test the hypothesis that echolocation behavior can be used to find the border between bat habitats. Assuming that bats react to background targets in “edge space” but not in “open space”, we determined the border between these two habitat types for commuting individuals of the parti-colored bat Vespertilio murinus. We recorded sequences of bats’ echolocation signals while they flew parallel to the walls of large buildings and to the ground and determined the signals’ average bandwidth, duration, and pulse interval. These parameters varied systematically with the estimated horizontal and vertical distances between the bats and the background. A distinct effect of horizontal distance to the background on echolocation behavior was found for horizontal distances of less than 6 m, thus indicating the border between edge and open space. Only a few bats flew at vertical distances below 5 m. However, enough passages at vertical distances of 5 m and above indicated that the vertical border is somewhere below a distance of 5 m. Within edge space, V. murinus reacted to the background by reducing signal duration, increasing bandwidth at closer distances, and often emitting one signal per wing beat. In open space, signal parameters did not vary as a function of distance to the background. There, V. murinus emitted the longest signals with the narrowest bandwidth and often made one or two wing beats without emitting a pulse. With our data we support with statistical methods the hypothesis that echolocation behavior reveals the border between the habitat types “edge” and “open space”.