Spatial Pattern

1] The interest about the exchange of water between streams and aquifers has been increasing among the hydrologic community because of the implications of the exchange of heat, solutes, and colloids for the water quality of aquatic environments. Unfortunately, our understanding of the relevance of the exchange processes is limited by the great number of coupled hydrological and geomorphological factors that interact to generate the complex spatial patterns of exchange. In this context, the present work presents a mathematical model for the surface-subsurface exchange through the streambed of a meandering stream. The model is based on the linearization of the equations that govern the hydrodynamics and the morphodynamics of the system, and it provides a first-order analytical solution of the coupled flow field of both the surface and the subsurface flows. The results show that stream curvature determines a characteristic spatial pattern of hyporheic exchange, with water upwelling and downwelling concentrated near the stream banks. The exchange can drive surface water deep into the sediments, thus keeping deep alluvium regions connected with the stream. The relationships between hyporheic exchange flux and the geometrical and hydrodynamical properties of the stream-aquifer system are also investigated.

Rapid adoption and expansion of the CCTV systems in Turkey as well as all over the world have produced a fair amount of ―technological determinism‖ among many law enforcement officials, which Norris and Armstrong (1999, p. 9) define as ―an unquestioning belief in the power of technology‖. As a matter of technological determinism, politicians and the public continue to myopically expect that the exclusive responsibility of preventing crime rest on the police-monitored CCTV cameras. Conversely, policy makers may be better informed if they consider why the law enforcement agencies should invest in the installation of the CCTV cameras in public areas based on the research. In fact, a well-designed evidence based paradigm in the CCTV literature is likely to reveal the truth about the question of ―does it work?‖
In addition to all previous methodological efforts, empirical evaluations in the CCTV literature are still needed to account for alternative perspectives to measure their effectiveness in the deterrence of crimes. Therefore, the present study focused on the concepts of environmental criminology, namely "crime risk at place". This research also considered the environmental risk values that might identify ―environmental conditions under which cameras would be most effective‖ (Caplan et al., 2011, p.271). Thus, the concept of ―Environmental risk value" provided a unique methodological approach to the police- monitored CCTV literature.
This study examined the impact of the metropolitan city of Bursa‘s city-wide system

and certain individual police-monitored CCTV camera‘s views used to scan the landscape, respectively on street level, including aggravated assault, auto theft, thefts from autos, and larceny theft crime incident numbers in a spatial distribution of locations; and analyzed whether the environmental risk value effects on the deterrent effect of police-monitored CCTV cameras on aforementioned crime types. To accomplish that statistical analyses (paired t test, location quotient, and regression models) and risk terrain modeling (RTM) were conducted in this dissertation.
Three important findings were found in this study. Firstly, city-wide system effect indicated that larceny thefts and thefts from auto experienced significant reduction. However, aggravated assaults and auto thefts were not. Secondly, the results from assessing the deterrent effect of certain individual police-monitored CCTV cameras on aggravated assaults, larceny thefts, thefts from autos and auto thefts were mixed. Finally, each individual CCTV camera has a unique environment – environmental risk value that influences its deterrent effect on – aggravated assaults, larceny thefts, thefts from autos and autos theft. Further, the affect was discernable and in positive direction for each crime type.
Environmental risk value assessments can advance our understanding of the deterrent effect of CCTV cameras at their viewshed areas. So environmental risk sites must be taken into account when the decision process concerning CCTV cameras is made by local and national level policy makers, police agencies and politicians who try to establish where the most appropriate location to install police-monitored CCTV cameras is. In this respect RTM can be considered as a pre intervention tool so that police agencies can measure the deterrent effect of CCTV before installation. Such a pre-evaluation process increases the capacity for effective police management and crime prevention strategies in police agencies.

This paper aims to develop and test methods for spatial mapping of population, food production, consumption, and marketed quantities in Africa. As an initial, exploratory exercise, the paper examines the spatial pattern of population, food production, consumption, and trade in the three countries of Zambia, Malawi and Mozambique. This largely descriptive initial work will lay the empirical foundations for future analytical work modeling regional trade flows of food staples. By mapping population, food production, and trade flows, the paper aims to help policy makers better understand and anticipate spatial interactions in staple food markets. Through visual presentation of market information, these spatial mapping tools offer prospects for animating an ongoing dialogue among public and private stakeholders on key market flows, key bottlenecks, and key opportunities for improving food security in good and bad harvest years.

Characterizing spatial patterns of fire behavior is an important and rarely considered means of understanding patterns of vegetation recovery following a fire event. Using geostatistics, we characterized spatial patterns of pre-burn fuel loads, fire temperature and duration during prescribed burns, and post-burn fuel loads in four longleaf pine stands in the southeastern USA. Fire temperatures exhibited moderate to strong spatial dependence over medium spatial scales. Variograms suggest that 61-99% of sample population variance was spatially dependent at scales of 27-157 m. Patterns of pre-burn fuel loads were only moderately related to patterns of mean fire temperature, confirming that fuel loads alone cannot predict fire patchiness. Other fuel parameters and microscale changes in wind and relative humidity likely influenced patterns of fire intensity as well. Strength and scale of fuel load spatial patterns were altered by fire as indicated by preand post-burn measurements. Spatial analysis provides a useful way to quantify burn patchiness and can help to identify which patch size may be desirable for different management goals. Studies that examine fire effects need to recognize spatial autocorrelation when characterizing fire behavior and account for this variation at appropriate scales.

Eigenvector mapping techniques are widely used by ecologists and evolutionary biologists to describe and control for spatial and/or phylogenetic patterns in their data. The selection of an appropriate subset of eigenvectors is a critical step (misspecification can lead to highly biased results and interpretations), and there is no consensus yet on how to proceed. We conducted a ten-year review of the practices of eigenvector selection and highlighted three main procedures: selecting the subset of descriptors minimising the Akaike information criterion (AIC), using a forward selection with double stopping criterion after testing the global model significance (FWD), and selecting the subset minimising the autocorrelation in the model residuals (MIR). We compared the type I error rates, statistical power, and R² estimation accuracy of these methods using simulated data. Finally, a real dataset was analysed using variation partitioning analysis to illustrate to what extent the different selection approaches affected the ecological interpretation of the results. We show that, while the FWD and MIR approaches presented a correct type I error rate and were accurate, the AIC approach displayed extreme type I error rates (100%), and strongly overestimated the R². Moreover, the AIC approach resulted in wrong ecological interpretations, as it overestimated the pure spatial fraction (and the joint spatial-environmental fraction to a lesser extent) of the variation partitioning. Both the FWD and MIR methods performed well at broad and medium scales but had a very low power to detect fine-scale patterns. The FWD approach selected more eigenvectors than the MIR approach but also returned more accurate R² estimates. Hence, we discourage any future use of the AIC approach, and advocate choosing between the MIR and FWD approaches depending on the objective of the study: controlling for spatial or phylogenetic autocorrelation (MIR) or describing the patterns as accurately as possible (FWD).

At the study area of Xigu District in Lanzhou City, using RS & GIS as tools we apply Diversity, Dominance, Fragmentation, Isolation and so on to study the quantitative, fractal and spatial characters of landscapes" structures in the four sub-regions divided by the morphological features. Using the Fractal Theory to establish the fractal structure models, we analyze the complexity and stability of various landscapes" distribution with fractal dimension value. The spatial distribution characteristics of landscape mosaic structure are also expounded. At the end of the paper we discuss the relevant problems on the main factors which control and effect on the spatial pattern of landscapes as well as on landscape optimization and management.

Spatial patterning of ecosystems can be explained by several mechanisms. One approach to disentangling the influence of these mechanisms is to study a patterned ecosystem along a gradient of environmental conditions. This study focused on hummock-hollow patterning of peatlands. Previous models predicted that patterning in drainage-dominated peatlands is driven by a peat-accumulation mechanism, reflected by higher nutrient availability in hollows relative to hummocks. Alternatively, patterning in evapotranspiration (ET)-dominated peatlands may be driven by a nutrient-accumulation mechanism, reflected by reversed nutrient distribution, namely, higher nutrient availability in hummocks relative to hollows. Here, we tested these predictions by comparing nutrient distributions among patterned peatlands in maritime (Scotland), humid temperate (Sweden), and humid continental (Siberia) climates. The areas comprise a climatic gradient from very wet and drainage-dominated (Scotland) to less wet and ET-dominated (Siberia) peatlands. Nutrient distribution was quantified as resource contrast, a measure for hummock-hollow difference in nutrient availability. We tested the hypothesis that the climatic gradient shows a trend in the resource contrast; from negative (highest nutrient availability in hollows) in Scotland to positive (highest nutrient availability in hummocks) in Siberia. The resource contrasts as measured in vegetation indeed showed a trend along the climatic gradient: contrasts were negative to slightly positive in Scotland, positive in Sweden, and strongly positive in Siberia. This finding corroborates the main prediction of previous models. Our results, however, also provided indications for further model development. The low concentrations of nutrients in the water suggest that existing models could be improved by considering both the dissolved and adsorbed phase and explicit inclusion of both nutrient-uptake and nutrient-storage processes. Our study suggests that future climate change may affect the ecosystem functioning of patterned peatlands by altering the contribution of pattern-forming mechanisms to redistribution of water and nutrients within these systems.

Changes in seasonal patterns of rainfall are key ecological factors. The definition of the spatial scale on which these changes can occur is particularly relevant in Mediterranean areas, where problems related to the variability of the pluviometric regime vary from one place to another. The region of Valencia is a good example of this kind of variability in rainfall regimes. To study changes in seasonal means and variability, we have applied non-parametric (Spearman test) and parametric techniques (linear model) to data from 97 pluviometric stations during the World Meteorological Organization (WMO) normal period, 1961 -1990. Special emphasis has been placed on the analysis of the spatial pattern of trends in means and variability. For this purpose, we have used a modified version of the Cramér-von Mises test in order to define subregional areas with similar rainfall evolution. Our results show a high spatial heterogeneity in rainfall evolution. The striking feature is the progressive dryness in the autumn season accompanied by an increase in interannual variability. Increases in winter and summer interannual variability, and decreases in rainfall amounts in winter are dominant too. We discuss these results in relation to rainfall generation mechanisms and their ecological implications.

Trends in daily precipitation and temperature extremes across western Germany in the second half of the 20th century. Int J Climatol ABSTRACT The evolution of daily extreme precipitation and temperature from 1958 to 2001 was investigated within the German side of the Rhine basin. Trends of a set of extreme precipitation and temperature indices defined on daily time series of precipitation and temperature were calculated at 611 precipitation and 232 temperature stations located within the study area and their corresponding significances were tested using the non-parametric Kendall-tau test. The results obtained indicated that both the daily minimum and maximum extreme temperatures have increased over the investigation period, with the degree of change showing seasonal variability. On an annual basis, the change in the daily minimum extreme temperature was found to be greater than that of the daily maximum extreme temperature. The daily extreme heavy precipitation has shown increasing trends both in magnitude and frequency of occurrence in all seasons except summer, where it showed the opposite trend. The station values of the daily precipitation were also interpolated on a regular grid of 5 km × 5 km so that the changes in the indices could be investigated on areal precipitation by aggregating the interpolated precipitation to any desired scale. This enables assessment of the hydrological consequences of the changes in the extreme precipitation. Although the spatial pattern remained more or less similar with that of the point-scale trends for all indices, the average trend magnitude showed an increase with the scale of the area on which precipitation was aggregated.

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In this paper, we develop an econometric analysis of the intra- and interregional trade flows of the accommodation, restaurant industry, and travel agency sectors in Spain by means of several specifications of the gravity model and three alternative databases containing the monetary flows for 2001 and 2007. The results obtained show the existence of an important border effect in favour of the intraregional trade of tourism, and verify a minor elasticity of the trade flows in some characteristic tourism sectors in relation to distance. Finally, the two main typologies of flows – tourist establishments and second homes – are modelled separately, identifying specific factors for explaining each category.

We analyse the factors controlling seedling establishment of Scots pine at its southernmost geographical limit (southern Spain), by monitoring emergence, survival and growth for up to 4 years in the microhabitats to which seeds are dispersed. Naturally established seedlings were monitored in two mountain ranges, and experimental sowings were performed both in woodlands and in adjacent successional shrublands into which the forest could expand. 2 Emergence was high in all microhabitats, although it was highest under the canopy of shrubs. Overall survival was low, with c. 90% of seedlings dying in the first growing season (c. 98% after several growing seasons). Survival differed among microhabitats, being highest under shrubs and extremely low (or zero) under pines or in bare soil. 3 Seedling growth was the highest in areas of bare soil, intermediate under shrubs, and very low under pines. 4 Establishment under pines was prevented by both mortality and poor performance, and good performance cannot counteract high mortality in the open. Shrubs, however, acted as nurse plants, buffering summer drought without reducing radiation to levels critical for growth, and protecting seedlings from ungulate trampling, hail and frost heave. 5 Patterns of recruitment were similar for woodland stands and successional shrublands. In addition, patterns of survival for naturally established seedlings were similar to those of seedlings originating from experimental sowings. 6 Juveniles were positively associated with shrubs but negatively with bare soil or areas below pine canopies. The facilitative effect of shrubs on seedling survival therefore changes the spatial pattern of recruitment from that determined by germination. 7 Overall, processes controlling seedling establishment in these southern Scots pine forests differ sharply from those operating in its main distribution area. The comparison among contrasting geographical ranges may contribute to an understanding of the role of environmental conditions in the balance between competition and facilitation, and assist in forecasting plant regeneration responses to global climate change.

Primary production on semiarid floodplains supports a diverse local and regional fauna. Reduced flooding from water resource development (WRD) may affect floodplain production by decreasing water and nutrient supply.We investigated the effects of reduced wetting on soil fertility by performing a regional soil survey across a gradient of flood frequency. Soil nitrogen (N), phosphorus (P) and carbon (C) were recorded over a soil-wetting event where heavy rainfall and flooding coincided.Soil nutrient concentrations indicate N limits plant growth and P does not.No spatial patterns in soil P were detected across the floodplain, suggesting that the principal mechanism controlling P fertility is the concentration of P in floodplain source material, and that flood mediated import and export of P are minor processes.Soil N concentrations rose following rainfall and flooding and the greatest increased occurred in flooded areas. Flood deposition of N accounted for only 9% of the boost in soil N in flooded areas, and N concentrations continued to rise when the floods and rains ceased. Elevated soil N levels do not appear to persist because at the start of a growth cycle, when soils were dry, soil N did not vary significantly with flood frequency. This suggests most of the boost in soil N was due to N-fixation, with the subsequent loss of N likely to have resulted from in situ processes such as denitrification.Agricultural export of nutrients appears to not be a significant process in the context of the high phosphorus fertility of floodplain source material and the apparently high rates of in situ processing of nitrogen.Synthesis and applications. Our data suggest that floodplain soil fertility is controlled by mechanisms other than flood frequency or agricultural export, meaning that WRD is unlikely to affect soil fertility; however, the biological implications of the brief pulse in soil N associated with wetting need further investigation.

In the boreal forest, fire, insects, and logging all affect spatial patterns in forest age and species composition. In turn, spatial legacies in age and composition can facilitate or constrain further disturbances and have important consequences for forest spatial structure and sustainability. However, the complex three-way interactions among fire, insects, and logging and their combined effects on forest spatial structure have seldom been investigated. We used a spatially explicit landscape simulation model to examine these interactions. Specifically, we investigated how the amount and the spatial scale of logging (cutblock size) in combination with succession, fire, and spruce budworm outbreaks affect area burned and area defoliated. Simulations included 30 replicates of 300 years for each of 19 different disturbance scenarios. More disturbances increased both the fragmentation and the proportion of coniferous species and imposed additional constraints on the extent of each disturbance. We also found that harvesting legacies affect fire and budworm differently due to differences in forest types consumed by each disturbance. Contrary to expectation, budworm defoliation did not affect area burned at the temporal scales studied and neither amount of logging nor cutblock size influenced defoliation extent. Logging increased fire size through conversion of more of the landscape to early seral, highly flammable forest types. Although logging increased the amount of budworm host species, spruce budworm caused mortality was reduced due to reductions in forest age. In general, we found that spatial legacies do not influence all disturbances equally and the duration of a spatial legacy is limited when multiple disturbances are present. Further information on post-disturbance succession is still needed to refine our understanding of long-term disturbance interactions.

This study concerned an experimental truffle bed of downy oaks infected by the ectomycorrhizal fungus Tuber melanosporum and planted in 1983. The presence of T. melanosporum creates rounded areas with little herbaceous cover, termed AbrulisB, where carpophores are found. Thê investigation was aimed at relating the occurrence and carpophore production of T. melanosporum to soil properties, i.e., organic matter, structure, aeration and fertility, expressed in terms of total organic C, aggregate size classes, DTPA-extractable Fe and Mn, and host plant height. Data were Ž . processed by multivariate geostatistical techniques. A linear model of coregionalization LMC Ž . Ž . Ž . including i a nugget effect, ii a short-range spherical structure with a range of 7 m and iii a long-range spherical structure with a range of 32 m, was fitted to the experimental direct and Ž . cross-variograms of the investigated properties. Factorial kriging analysis FKA was used to separate the sources of variation of the data according to the spatial scale at which they operate, and to summarize and map them in terms of spatial factors. An indicator approach was adopted to estimate and map the conditional probability of presence and fructification of T. melanosporum. The visual comparison between the spatial pattern of the long-range structure of the first regionalized factor with the probability map of finding brulis plus carpophore production revealed ) Corresponding author. A. Castrignano . 0016-7061r00r$ -see front matter q 2000 Elsevier Science B.V. All rights reserved.

One of the key agreements adopted at the Rio Conference in 1992 was the Convention on Biological Diversity (CBD). Both in practice and research biodiversity has been mainly addressed in a non-urban context, often discussed in relation to issues such as the depletion of rainforests and desertification. However, as more than half of the world population are urban dwellers, it is increasingly urgent to discuss the application of the concept of biodiversity within an urban context. Issues approached in this article are: What does it mean to talk about biodiversity in an urban context? Is biodiversity a meaningful goal for urban politics and planning? Is there empirical evidence of implementing biodiversity in urban politics and planning? After an introduction, the article is organized into four sections. In the second section the concept of biological diversity is defined with special reference to its application in an urban context. Biodiversity and its relationship to urban governance is the topic of the third section, followed by a section analysing examples of how this relationship is practised in selected Swedish cities. The final section highlights five major conclusions with regard to the application of biodiversity in an urban context: (1) that all cities studied have adopted overall 'green' policies, including biodiversity as one component; (2) that local coalitions in favour of implementing biodiversity have been established between employees at different offices, between employees and politicians, and between employees and NGOs; (3) that there are in all cases tangible signs of spatial patterns and structures that are favourable to biodiversity; (4) that urban biodiversity, for its successful implementation, needs to be related, and accommodated to other values given priority in current policymaking, such as recreation; (5) that mainstream biodiversity analysis should be complemented by an urban landscape approach. Finally, the article returns to the more general question of what biodiversity could and should mean in urban planning.

From a conservation point of view, species" tolerances towards disturbance are often generalised and lack reference to spatial scales and underlying processes. In order to investigate how average typical species react to habitat fragmentation and disturbance, we adopted a multi-species approach to address occupancy patterns of five specialised dune arthropods (butterflies Hipparchia semele, Issoria lathonia; grasshopper Oedipoda caerulescens; spiders Alopecosa fabrilis, Xysticus sabulosus) in recently fragmented coastal dune habitats which are subjected to varying levels and modes of local disturbance, i.e. trampling by cattle or people. Occupancy patterns were assessed during two successive years in 133 grey dune fragments of the Flemish coastal dunes (Belgium, France). By treating species as a random factor in our models, emphasis was placed on generalisations rather than documenting species-specific patterns. Our study demonstrates that deteriorating effects of local disturbance on arthropod incidence cannot be interpreted independent of its landscape context, and appear to be more severe when patch area and connectivity decrease. When controlled for patch area and trampling intensity, the probability of species occupancy in poorly connected patches is higher under cattle trampling than under recreation. Incidences additionally decrease with increasing intensity of cattle trampling, but increases with trampling by tourists. This study provides empirical evidence of mode-and landscape-dependent effects of local disturbance on species occupancy patterns. Most importantly, it demonstrates that trampling of sensitive dune fragments will lead to local and metapopulation extinction in landscapes where trampling occurs in a spatially autocorrelated way, but that the outcome (spatial patterns) varies in relation to disturbance mode, indicating that effects of disturbance cannot be generalised. Trampling and dune-arthropod occurence-Bonte & Maes 3 Zusammenfassung Aus Sicht des Naturschutzes werden die Toleranzen von Arten gegenüber Störungen häufig verallgemeinert und lassen einen Bezug zu räumlichen Skalen und den zugrundeliegenden Prozessen vermissen. Um zu untersuchen, wie typische Durchschnittsarten auf Habitatfragmentierung und Störung reagieren, verwendeten wir einen Vielartenansatz um die Nutzungsmuster von fünf spezialisierten Dünenarthropoden (Schmetterlinge: Hipparchia semele, Issoria lathonia; Heuschrecken: Oedipoda caerulescens; Spinnen: Alopecosa fabrilis, Xysticus sabulosus) in kürzlich fragmentierten Küstendünenhabitaten zu behandeln, die unterschiedlichen Arten und verschieden starken lokalen Störungen ausgesetzt waren, wie z. B. Vertritt durch Weidevieh oder Menschen. Die Nutzungsmuster wurden in zwei aufeinander folgenden Jahren in 133 Graudünenfragmenten der flämischen Küstendünen (Belgien, Frankreich) untersucht. Durch die Berücksichtigung der Arten als zufällige Faktoren legten wir den Schwerpunkt eher auf Generalisierung als auf die Dokumentation artspezifischer Muster. Unsere Untersuchung zeigt, dass die negativen Effekte lokaler Störungen auf die Arthropodenvorkommen nicht unabhängig vom Landschaftskontext interpretiert werden können, und dass sie ernster sind, wenn die Flächengröße und-vernetzung abnehmen. Wenn wir die Flächengröße und die Vertrittintensität kontrollieren, ist die Wahrscheinlichkeit des Artvorkommens in wenig vernetzten Flächen bei Beweidung größer als bei Freizeitnutzung. Die Vorkommen nehmen außerdem mit zunehmender Intensität des Weideviehvertritts ab, nehmen jedoch mit zunehmendem Vertritt durch Touristen zu. Diese Untersuchung liefert empirische Belege für art-und landschaftsabhängige Effekte lokaler Störungen auf die Nutzungsmuster von Arten. Besonders wichtig ist, dass gezeigt wird, dass der Vertritt von sensiblen Dünenfragmenten zum Aussterben von lokalen und Metapopulationen in Landschaften führen wird, wenn der Vertritt in einer räumlich autokorrelierten Form stattfindet. Das Ergebnis (die räumlichen Muster) variieren jedoch in Relation zur Störungsart und weist darauf hin, dass die Effekte von Störungen nicht generalisiert werden können.

The trends in tropical cyclone (TC) induced wind and precipitation are estimated by applying a quantile regression to station data collected from mainland China. Results indicate that stations located close to the southeast coast show significant decreasing trends in annual windy days, maximum sustained wind and wind gusts, while positive trends in precipitation per TC and maximum 1-hr precipitation dominate over the south of the Yangtze River. The TC frequency is generally decreased over China, especially over south China. The location of significant trends in precipitation seems to be related to the mountains and coastline in southeast China. The influence of local conditions, such as topography and urbanization, on circulation may contribute to the spatial pattern of trends in influence of TC activity. The different behaviors of trends in wind and precipitation also necessitate a more thorough metrics for assessing the impacts of TCs.

Objective: To study temporal and spatial development of EEG patterns in sporadic and iatrogenic Creutzfeldt-Jakob disease patients. Methods: Temporal and spatial development of EEG patterns in 4 patients with sporadic Creutzfeldt -Jakob disease and 2 patients with iatrogenic Creutzfeldt -Jakob disease due to implantation of contaminated brain depth electrodes were investigated. A total of 56 EEGs were analyzed, over time spans ranging from 1272 to 3 days prior to death.

Our ability to demonstrate statistical patterns of invasion by non-native species will determine the success of future management projects. We investigated the suitability of self-organizing maps (SOM, neural network) for patterning habitat invasion by exotic fish species at the regional scale (Southwest France), using a binary dataset of species occurrences. The SOM visualization can be used as an analytical tool to bring out relationships between sample locations and biological variables, but in addition the weight of each species in the output of the SOM can be interpreted as its occurrence probability in various geographic areas. After training the SOM with fish presence/absence data, the k-means algorithm helped to derive three major clusters of sites (headwater, montane, and plain areas). Each cluster was divided into two subsets of sites according to non-native fish, because assemblage compositions delineated different geological areas: Pyrenees Mountains, Massif Central Moun...

Predators can play important roles in structuring their communities through topdown effects on the distribution and abundance of their prey. Sharks are top predators in many marine communities, yet few studies have quantified those factors influencing their distribution and hunting behaviour. Here, we use location data from 340 predatory interactions between white sharks Carcharodon carcharias (Linnaeus), and Cape fur seals Arctocephalus pusillus pusillus (Schreber), data on associated environmental factors, and spatial analysis, including a novel application of geographic profiling -a tool originally developed to analyse serial crime -to investigate spatial patterns of shark attack and search behaviour at Seal Island in False Bay, South Africa. We found that spatial patterns of shark predation at this site are nonrandom. Sharks appear to possess a well-defined search base or anchor point, located 100 m seaward of the seal's primary island entry-exit point. This location is not where chances of intercepting seals are greatest and we propose it may represent a balance among prey detection, capture rates, and competition. Smaller sharks exhibit more dispersed prey search patterns and have lower predatory success rates than larger conspecifics, suggesting possible refinement of hunting strategy with experience or competitive exclusion of smaller sharks from the most profitable hunting locations. As many of the features of this system will be common to other instances of foraging, our conclusions and approach employed may have implications and applications for understanding how large predators hunt and for studying other predator-prey systems.

We present a model that deals with continuous space and functional regions in the form of overlapping, interacting, and constantly changing contact fields associated with the individual actors in a labor market. Simulations illustrate the results of the model, presenting individual histories of firms and workers. The model demonstrates the importance of the relative location of t h e firm and the employee in terms of the effort needed t o construct functional contact fields. Firms and workers located at either the boundary of the region or in isolated interior positions endure two locational effects: the reduced ability t o gather information and t o recruit workers d u e t o a truncated or low-density contact field.

This paper sets out a conceptual framework for modelling events in aquatic ecosystems as coupled processes in catchments, water columns and sediments. This theoretical framework is developed using ideas from the behaviour of complex adaptive systems. I show that it is possible to use similar models for each subsystem and that there are analogous processes in each, differing only in scale. In this framework the phytoplankton appear as 'system canaries'. Nuisance algal blooms appear as a result of perturbations to the system biogeochemistry at a range of scales. Macrophytes are identified as important components of the coupled catchment, water, sediment system.

Past work on tree-to-tree interactions in semi-arid savannas, through the use of nearest neighbour analysis, has shown both a regular dispersion pattern and a positive correlation between the size of a tree and the distance to its nearest neighbour. From these results, the importance of competition has been inferred. In the present study, treeto-tree interactions in a mesic savanna woodland at Marondera, Zimbabwe, dominated by relatively small-sized individuals of Brachystegia spiciformis and Julbernardia globiflora, were examined. Results show that the regular dispersion pattern is uncommon; that there are few significant positive correlations between size of individual and distance to nearest neighbour; and that growth rate is not consistently correlated with size and distance of nearest neighbour. Results of a study of regeneration relative to canopy cover suggest a possible mechanism for these findings: unlike semi-arid savannas, young plants often grow in under-canopy environments so that early spacing of young trees does not occur. Significant positive correlations between the size of a tree and the distance to its nearest neighbour were found in a stand of larger, presumably older, trees, suggesting that such a relationship only develops in mesic miombo woodland through a thinning process as the trees mature. Familial clumping, which is common in the study area, may mask spatial patterns.

The tidal migration, temporal and spatial patterns in feeding of the surface-swimming four-eyed fish Anableps anableps (Anablepidae) were studied in a macrotidal mangrove area in north Brazil to exemplify the ecology of a tropical intertidal fish. Visual censuses in the main channel showed that abundances were high at low water (LW) and low at high water (HW). Anableps anableps entered the intertidal creeks with the first flood rise. They fed in the inundated mangrove at HW and returned gradually after the ebb current maximum to concentrate again in the subtidal parts of the main channel at LW. This pattern occurred at neap, mid and spring tides throughout the year. The tidal migration was triggered by water level, not by time. In the study area the diet of A. anableps caught with block nets was dominated by intertidal red algae (Catanella sp.). Other important food items were Insecta and Grapsidae. The combination of high inundation and daylight (spring tide-day) provided the best foraging conditions, probably emphasizing the importance of the above-water eye. Darkness and low inundation was linked to poorest foraging conditions (neap tide-night). The quantity of food consumed by A. anableps was clearly influenced by the factors tide, time of day and creek location, but not by size and sex. The qualitative composition of the diet was not influenced by any of the factors, except for mud, which was only ingested at neap tides. The temporal and spatial variability in food consumption suggests that food web modelling in macrotidal areas may lead to misinterpretations of the overall systems dynamics if the spring and neap tide alternation and the diurnal cycle are not considered.

We analyze a set of nine regional climate model simulations for the period 1961-2000 performed at 25 and 50 km horizontal grid spacing over a European domain in order to determine the effects of horizontal resolution on the simulation of precipitation. All of the models represent the seasonal mean spatial patterns and amount of precipitation fairly well. Most models exhibit a tendency to over-predict precipitation, resulting in a domain-average total bias for the ensemble mean of about 20% in winter (DJF) and less than 10% in summer (JJA) at both resolutions, although this bias could be artificially enhanced by the lack of a gauge correction in the observations. A majority of the models show increased precipitation at 25 km relative to 50 km over the oceans and inland seas in DJF, JJA, and ANN (annual average), although the response is strongest during JJA. The ratio of convective precipitation to total precipitation decreases over land for most models at 25 km. In addition, there is an increase in interannual variability in many of the models at 25 km grid spacing. Comparison with gridded observations indicates that a majority of models show improved skill in simulating both the spatial pattern and temporal evolution of precipitation at 25 km compared to 50 km during the summer months, but not in winter or on an annual mean basis. Model skill at higher resolution in simulating the spatial and temporal character of seasonal precipitation is found especially for Great Britain. This geographic dependence of the increased skill suggests that observed data of sufficient density are necessary to capture fine-scale climate signals. As climate models increase their horizontal resolution, it is thus a key priority to produce high quality fine scale observations for model evaluation.

Maps of current and potential vegetation spatial patterns can be used to assess land cover changes, and aid in ecosystem management and restoration. The vegetation spatial patterns of subalpine forest species are largely controlled by variation in temperature, water and solar radiation resources. These fundamental resources were quantified across a 1100-km 2 landscape using biophysical models, a digital elevation model (DEM), and weather station data. Field data of species abundances were used to define species-habitat relationships and calibrate maximum likelihood classifications of the biophysical gradients. For comparison, a standard land cover classification of Landsat Thematic Mapper satellite imagery had an overall accuracy 68.3%. Using the biophysical gradients alone gave a similar 67.4% accuracy. The highest accuracy classification (83.2%) used both biophysical and spectral data. The biophysical resources were also used to map the presence or absence of four herb and shrub species that cannot be sensed remotely. These predictions ranged from 60% to 79% accurate. Maps of relative abundance were less accurate, from 61% to 63.2%. This low result may be due to historical and stochastic events, or simply a small data set. The spatial pattern of species and communities that are controlled by resources can be predicted using general biophysical models. The species-habitat relationships can also be used to improve remote sensing products.

Frugivores often track ripe fruit abundance closely across local areas despite the ephemeral and typically patchy distributions of this resource. We use spatial auto-and cross-correlation analyses to quantify spatial patterns of fruit abundance and avian frugivory across a 4-month period within a forested 4.05-ha study grid in Puerto Rico. Analyses focused on two tanager species, Spindalis portoricensis and Nesospingus speculiferus, and their principal food plants. Three broad questions are addressed: (1) at what spatial scales is fruit abundance and frugivory patchy; (2) at what spatial scales do frugivores respond to fruit abundance; and (3) to what extent do spatial patterns of frugivory overlap between bird species? Fruit patch size, species composition, and heterogeneity was variable among months, despite fruit patch locations remaining relatively consistent between months. Positive correlations between frugivory and fruit abundance suggested tanagers successfully tracked fruit abundance. Frugivory was, however, more localized than fruit abundance. Scales of spatial overlap in frugivory and monthly variation in the foraging locations of the two tanager species suggested that interspecific facilitation may have been important in determining bird foraging locations. In particular, S. portoricensis, a specialist frugivore, may have relied on the loud calls of the gregarious generalist, N. speculiferus, to find new foraging areas. Such a mechanism could help explain the formation of mixed species feeding flocks and highlights the potential importance of facilitation between species that share resources.

Using firm-level survey data from Barcelona, Stockholm, Vienna in Europe and Singapore, Penang (Malaysia) and Bangkok in SouthEast Asia the paper enquires into the different R&D and innovation behaviour of multinational and local companies in these Metropolitan Regions. Scrutinizing a set of input, throughput and output indicators as well as information on cooperation characteristics, we try to evaluate a) if the spatial pattern of more (intense) innovation activity in Europe when compared to SouthEast Asia is still valid; and b) if there are reasons to believe that R&D units of multinational corporations in Europe are mainly concerned with the enhancement of the knowledge base and the development of future competitiveness by tapping into localized knowledge and using the particular host regions' innovation systems, while, on the other hand, MNCs in SouthEast Asia use R&D to support existing production facilities in order to exploit an existing competitive advantage. We are able to show that there is still a major gap in the innovation performance between SouthEast Asia and Europe and that there are indeed indications that R&D units in Europe are more orientated towards the augmentation of the company's knowledge base.

Spatial patterns of Emberizidae (Aves:Passeriformes) diversity and selection of priority areas for Cerrado conservation. The aim of this work was to design priority areas for conservation in the Cerrado region, Brazil, based on Emberizidae (Aves) diversity. We analyzed the overlap of complementarity networks of areas in the biome needed to represent all the species of the group (irreplaceability), as well

Samples of polyethylene pellets were collected at 30 beaches from 17 countries and analyzed for organochlorine compounds. PCB concentrations in the pellets were highest on US coasts, followed by western Europe and Japan, and were lower in tropical Asia, southern Africa and Australia. This spatial pattern reflected regional differences in the usage of PCBs and was positively correlated with data from Mussel Watch, another monitoring approach. DDTs showed high concentrations on the US west coast and in Vietnam. In Vietnam, DDT was predominant over its metabolites (DDE and DDD), suggesting the principal source may be current usage of the pesticide for malaria control. High concentrations of pesticide HCHs were detected in the pellets from southern Africa, suggesting current usage of the pesticides in southern Africa. This study demonstrates the utility and feasibility of the International Pellet Watch approach to monitor POPs at a global scale.

Tropical montane forests have been recognised as having global conservation importance. However, they are being rapidly destroyed in many regions of the world. Our study focuses on the rate of loss and patterns of fragmentation in tropical montane forests in the Highlands of Chiapas, Mexico, during a 25-year period. Data from Landsat satellite imagery from 1975 (MSS), 1990 (TM) and 2000 (ETM+) were used to ascertain annual deforestation rates of 1.3 and 4.8% for the 1975-1990 and 1990-2000 periods, respectively. Spatial patterns of forest fragmentation were identified using selected landscape indices. Increases in the number of forest fragments (3520-10,542), patch density (1.0-3.2 patches/100 ha), and total edge length (24,781-38,400 km) were associated with decreases in the mean patch size (65.0-8.7 ha), largest patch index (60.7-4.0%), total core area (99,422-9,611 ha), and mean proximity index (101,369-1405). The observed trends indicate increasing deforestation and fragmentation, particularly during the 1990-2000 period. Circa 50% of the forest cover in the Highlands has been lost in 25 years, and a proportion of the remaining forests have been degraded as a result of human use. Increasing human population and a more demanding use of soils for agriculture and timber arise as the major causes of deforestation in the study area. We suggest that conservation efforts should be focused on the management of the natural system and the management of the external influences on it, particularly the detection of hotspots, passive and active restoration and sustainable forest exploitation by the local indigenous communities. # Maximum probability for evidence derived from expert knowledge was set at 0.8 thus allowing uncertainty to be incorporated in the classification procedure. MCF = montane cloud forest; OF = oak forest; POF = pine-oak forest; PF = pine forest; CP = coffee plantation; NF = non-forest.

Previous studies of the spatial pattern of stream invertebrate drift have focused on spatial variation at microhabitat scales or landscape scales, or temporal variation over diel or seasonal scales. None have examined consistency in spatial variation over longer time scales (>1 year). This study examined invertebrate drift density and composition at fixed locations (terminal ends of 10 riffles) each month at day and night along a 1 km reach of a 2nd order stream over a period of nearly 2 years. Consistent differences in the density of macroinvertebrate drift between riffles over 2 years were observed. The only habitat characteristic observed to be related to invertebrate drift density was the length and size of riffles above sampling sites, with larger and longer riffles producing the highest drift densities. Consistent differences in the supply of drifting macroinvertebrates along a stream reach may have implications for the supply of colonists to substrate patches and the profitability of feeding positions for drift-feeding fish and other predators.

We investigate the formation of transverse patterns in a doubly resonant degenerate optical parametric oscillator. Extending previous work, we treat the more realistic case of a spherical mirror cavity with a finite-sized input pump field. Using numerical simulations in real space, we determine the conditions on the cavity geometry, pump size and detunings for which pattern formation occurs; we find multistability of different types of optical patterns. Below threshold, we analyze the dependence of the quantum image on the width of the input field, in the near and in the far field.

Chandra, S., Chhetri, P. and J. Corcoran (2009).Spatial patterns of urban compactness in Melbourne: an urban myth or a reality. In: Ostendorf B., Baldock, P., Bruce, D., Burdett, M. and P. Corcoran (eds.), Proceedings of the Surveying & Spatial Sciences Institute Biennial ...

We examined spatial patterns of trends in ice phenology and duration for 65 waterbodies across the Great Lakes region (Minnesota, Wisconsin, Michigan, Ontario, and New York) during a recent period of rapid climate warming (1975-2004). Average rates of change in freeze (3.3 d decade 21) and breakup (22.1 d decade 21) dates were 5.8 and 3.3 times more rapid, respectively, than historical rates (1846-1995) for Northern Hemisphere waterbodies. Average ice duration decreased by 5.3 d decade 21. Over the same time period, average fall through spring temperatures in this region increased by 0.7uC decade 21 , while the average number of days with snow decreased by 5.0 d decade 21 , and the average snow depth on those days decreased by 1.7 cm decade 21. Breakup date and ice duration trends varied over the study area, with faster changes occurring in the southwest. Trends for each site were compared to static waterbody characteristics and meteorological variables and their trends. The trend toward later freeze date was stronger in large, low-elevation waterbodies; however, freeze date trends had no geographic patterns or relationships to meteorological variables. Variability in the strength of trends toward earlier breakup was partially explained by spatial differences in the rate of change in the number of days with snow cover, mean snow depth, air temperature (warmer locations showed stronger trends), and rate of change in air temperature. Differences in ice duration trends were explained best by a combination of elevation and the local rate of change in either temperature or the number of days with snow cover.

Reproductive biology and social behaviour of the parrotfish Sparisoma cretense was studied in the Azores Islands, northeast Atlantic, to characterize its spawning season and general reproductive biology in the region, to clarify the species mating system and associated spawning behaviours, and to evaluate the relationship between its reproductive traits and habitat features. S. cretense exhibits a dual mating system where males hold female harems within year-round territories or live in multi-male groups. Group behaviour predominates in smaller size classes, and territoriality in larger size classes. Males mature and become territorial earlier in life than females, and the best territories are held by larger males. The two behavioural modes are usually spatially segregated, with larger territorial fish preferring exposed and deeper reef ledges, and group fish occupying shallower, protected habitats. However, they frequently interact and overlap in space, especially during reproduction in the summer. Our findings indicate a highly competitive system and suggest that high quality spawning sites are important for the reproductive success of both types of fish. Patchiness of habitat along shorelines determines the relative distribution and equilibrium of territorial versus group fish. The complexity of this relationship between social structure and habitat might impact the populations' productivity, and could influence the success of marine protected areas for this species.

Chl-Zr 26 and Chl-ZML relationships. This important role of ocean physics indicates that the observed Chl changes primarily reflect biomass changes due to dampened or increased nutrient fluxes to the upper lit layers. Changes in the photoacclimation state of phytoplankton probably also intervene, without obscuring the global picture, however. Quantifying the respective role of both phenomena would require the parallel examination of Chl and other quantities more directly tied to biomass.

The free particle (< 2.5 [tm) composition data from seven National Park Service locations in Alaska for the period from 1986 to 1995 was performed using a new type of factor analysis, positive matrix factorization (PMF). This method uses the estimates of the error in the data to provide optimum data point scaling and permits a better treatment of missing and below detection limit values. Eight source components were obtained for data sets from the Northwest Alaska Areas and the Ber;mg Land Bridge sites. Five to seven components were obtained for the other Alaskan sites. The solutions were normalized by using aerosol f'me mass concentration data. Squared correlation coefficients between the reconstructed mass obtained from aerosol composition data for the sites and the measured mass were in the range of 0.74-0.95. Two factors identified as soils were obtained for all of the sites. Concentrations for these factors for most of the sites have maxima in the summer and minima in the winter. A sea-salt component was found at five locations. A factor with the highest concentrations of black carbon (BC), H +, and K identified as forest fire smoke was obtained for all data sets except at Katmai. Factors with high concentrations of S, BC-Na-S, and Zn-Cu were obtained at all sites. At three sites, the solutions also contained a factor with high Pb and Br values. The factors with the high S, Pb, and BC-Na-S values at most sites show an annual cycle with maxima during the winter-spring season and minima in the summer. The seasonal variations and elemental compositions of these factors suggest anthropogenic origins with the spatial pattern suggesting that the sources are distant from the receptor sites. The seasonal maxima/minima ratios of these factors were higher for more northerly locations. Four main sources contribute to the observed concentrations at these locations: long-range transported anthropogenic aerosol (Arctic haze aerosol), sea-salt aerosol, local soil dust, and aerosol with high BC concentrations from regional forest fires or local wood smoke. A northwest to southeast negative gradient suggesting long-range transport of air masses from regions north or northwest of Alaska dominated the spatial distribution of the high S factor concentrations.