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Knowledge on cheetah population densities across their current range is limited. Therefore, new and efficient assessment tools are needed to gain more knowledge on species distribution, ecology and behaviour. Scat detection dogs have emerged as an efficient and non-invasive method to monitor elusive and vulnerable animal species, like cheetahs, due to the dog’s superior olfactory system. However, the success of locating scat using detection dogs can be significantly improved under suitable weather conditions. We examined the impact of temperature, humidity and wind speed on detection rates of scat from cheetahs during a scat detection dog survey in Northern Kenya. We found that average wind speed positively influences the scat detection rate of detection dogs working on leash. Humidity showed no significant influence. Temperature showed a strong negative correlation with humidity and thus was excluded from our model analyses. While it is likely that wind speed is especially invalid for dogs working off leash, this study did not demonstrate this. Wind speed could thus influence the success of monitoring cheetahs or other target species. Our findings help to improve the survey and thus maximise the coverage of study area and the collection of target samples of elusive and rare species.

In today’s information age, thematic maps increasingly appear in all kinds of media and publications and many users control the map design process themselves. Due to wider prevalence of data, teach...

Maps have been used for centuries to depict the diverse facets of our environment. Thematic maps depict a specific theme and help in revealing geospatial patterns and relations. The study and pract...

The increase in massive volumes of point data that are continuously being generated calls for more powerful solutions to analyze and explore this data. Very often, such data includes a direct or indirect reference to a location on the Earth and can then be referred to as ‘big geospatial data’. Maps are one of the best ways to assist humans with understanding geospatial relationships in such data. In this paper, we present a comprehensive workflow for generating all possible thematic map types from two-dimensional univariate big geospatial point data. The objective is twofold: to facilitate and support thematic map automation, and to make this information accessible to software developers. The workflow illustrates processing steps, design choices and dependencies between them based on the characteristics of input data. Processing steps and design choices that can be automated and those requiring human intervention are identified. The scope of the workflow in this paper was restricted to two-dimensional univariate geospatial point data and planar and true geometrical map depictions. The results presented in this paper support the development of geovisualization and geovisual analytics tools for big geospatial data.

Python programming and the application of web services technology can be considered important skills for geomatics students when looking for employment later. A course on Web Processing Services (WPS) as part of the International Geomatics master programme at Karlsruhe University of Applied Sciences takes this into consideration while using the opportunity of making students aware of less-known thematic mapping methods. Students are introduced to automating a complex geoprocessing task and finally wrapping it into a WPS. It is achieved by following the phases of first conceptualizing the single steps before then using ArcGIS ModelBuilder and Python scripts in combination to build the processing chain. The alternate band map method serves as example in the hands-on exercise. Later students are asked to automate the generation of the geometries for the map face and/or map legend supporting other thematic mapping methods like the square density map or the absolute value raster map. The paper discusses the teaching approach and experiences made so far. Conceptualizing the automatization of a given complex geoprocessing problem proved to be the most challenging part for the students.

A purpose-built mobile data collection application is used to plan and implement community-oriented primary care (COPC) in a pilot project in the City of Tshwane (South Africa). Web reports present the data in the form of tables, graphs and point maps, but other types of thematic maps have not yet been implemented. We describe a proof-of-concept web map application that presents the COPC data in different cartographic representations. To reveal spatio-temporal patterns and correlations in the daily growing dataset, the user can choose between choropleth maps, segmented proportional circle maps, or a combination of these. The data is shown aggregated by administrative unit or by regular grid cell. As the user zooms in, the aggregation level automatically changes to smaller aggregation units. The setting of a threshold ensures data privacy protection. Spider diagrams link households visited by community health workers during a user-specified period to the sending clinic. The web maps can empower those involved in COPC to dynamically tailor health care provision to the complexity of people’s health needs. It is a valuable addition to the mobile application and web reports, and could contribute to more effective and efficient service delivery to meet the specificity of localized needs.

Although climate change is highly prevalent in the media, people in Europe and the United States are often unsure about climate change terms, processes, and its personal consequences. In other word...

To date, most studies on uncertainty visualisations have focused on two-dimensional representations. The closing of the software gap between three-dimensional (3D) graphics and geovisualisation pre...

The Faculty of Information Management and Media (IMM) at Karlsruhe University of Applied Sciences received funding for a project called ‘Fremdsein 4.0’. It targeted experiences about educational migration through applying various media means. Two interdisciplinary workshops were conducted focussing on the German words ‘Fremdsein’ and ‘Heimat’ as main topics, which relate to feelings of “foreignness” or of being at home. Among other results, two Web map apps that help to reflect on the two terms were conceptualized and evolved over time to become part of an exhibition towards the end of the project. The paper starts with describing the various contexts in which the map apps are placed: maps used in exhibitions, a reflection on ‘Fremdsein’, interdisciplinary learning and conceptualizing, and finally Web mapping and personalized maps. Next, the process of the map app development is covered, which led to two robust browser-based offline apps named ‘Ideal Home Finder’ and ‘Emotional Foreignness Ranking’. The former app, based on the research of Hofstede et al., makes use of empirically derived dimensions on cultural differences. By answering six questions, the user can find out in which countries he/she might feel at home. The latter app, which more directly resulted from workshop outcomes and personal experiences of the participants, allows to come up with rankings of emotional “foreignness” for five previously selected countries. We discuss and conclude with reflections on the two workshops, the developed apps and the exhibition.

Geospatial tools in a Web 2.0 environment can encourage citizens to engage with and influence their environment through online participation. In the field of geomatics, today’s students have to develop competencies in current technologies and learn how to adapt to continuously and rapidly changing technologies and applications. At the same time, we live in a globalized world where we increasingly deal with people from different backgrounds or have to commute to unknown places and environments for work. In this paper, we report about the experiences of students and lecturer participants from Germany and South Africa in a summer school on geomatics and participation, held in Karlsruhe, Germany, in July 2016. The starting point was to learn about nature conservation in Germany, particularly about the Rhine floodplains close to Rastatt. Mobile mapping apps were developed for this area with the aim of supporting conservation efforts. Confronting the participants with a new geographic area, a software development environment unknown to them and group work with participants from both universities has led to interesting insights beyond getting to know the partner university. From an evaluation of the summer school by participants, it was evident that the summer school succeeded in raising interest for participation in the student exchange programme and that participants expect clear guidance on the objectives of different activities. The balance between socializing and work provides a unique atmosphere for effective teaching and working, making a summer school such an enjoyable experience for students and lecturers.

Tropical forests are increasingly threatened by anthropogenic activities often resulting in habitat and biodiversity loss. To effectively manage and protect these areas, it is important to have an understanding of the factors affecting their biodiversity. Previous research has shown that birds in tropical regions are severely affected by human-induced habitat conversion and disturbance. The effects, however, are often area and guild-specific and the underlying mechanisms are frequently unclear. In this study, we disentangle and quantify the direct and indirect effects of human population density, distance to forest edge, habitat disturbance, and vegetation structure and composition on the total abundance and species richness of birds in Kakamega Forest, Kenya. Specifically, we use structural equation modeling to develop and test path models, which reflect the potential causal relationships between the bird assemblages and the chosen explanatory factors. Relationships were tested on the overall bird community and on five different guilds, classified according to birds’ forest specialization and feeding preferences (i.e. forest specialists, generalists and visitors, and frugivores and insectivores). Results showed that habitat disturbance, caused by logging, had a weak positive direct effect on the bird communities, but also had a strong detrimental indirect effect, particularly on the total abundance and species richness of forests specialists and insectivores. The negative effect was mediated through changes in the forest’s vegetation structure and composition. Shorter distances to the forest edge also had a negative effect, on all bird categories except on forest visitors, which also benefited from higher levels of disturbance. Our study shows that although in some cases habitat disturbance may have no strong direct negative effects it can still negatively influence bird communities in an indirect way. In the case of Kakamega Forest, we suggest that to conserve bird communities it is important to maintain the forest’s compositional and structural diversity by reducing human-induced habitat disturbance, such as illegal logging activities.

Over the last 100 years the Kakamega-Nandi forests area, western Kenya, experienced a loss of about 60 % in natural forest cover due to human interferences. In order to create awareness for sustainable forest use among the local population, tools for environmental education have been developed. The tools, here among others a jigsaw puzzle and a card game, aim at making use of geospatial data because map reading literacy is considered a prerequisite in any natural resource management and planning. The tools are introduced as well as the chosen participatory approach, which allowed enhancement of prototypes in an iterative manner.

Large-scale modifications of natural ecosystems lead to mosaics of natural, semi-natural and intensively used habitats. To improve communication in conservation planning, managers and other stakeholders need spatially explicit projections at the landscape scale of future biodiversity under different land-use scenarios. For that purpose, we visualized the potential effect of five forest management scenarios on the avifauna of Kakamega Forest, western Kenya using different measures of bird diversity and GIS data. Future projections of bird diversity combined: (1) remotely sensed data on the spatial distribution of different forest management types; (2) field-based data on the biodiversity of birds in the different management types; and (3) forest management scenarios that took into account possible views of various stakeholder groups. Management scenarios based on the species richness of forest specialists were very informative, because they reflected differences in the proportions of near-natural forest types among the five scenarios. Projections based on community composition were even more meaningful, as they mirrored not only the proportions of near-natural forest types, but also their perimeter to area ratios. This highlights that it is important to differentiate effects of the total area of available habitat and the degree of habitat fragmentation, both for species richness and community composition. Furthermore, our study shows that an approach that combines land-use scenarios, remote sensing and field data on biodiversity can be used to visualize future biodiversity. As such, visualizations of alternative scenarios are valuable for successful communication about conservation planning considering different groups of stakeholders in species-rich tropical forests.

A student assignment within the concluding module on map compilation is taken to elaborate on the difference between maps (cartography) and info graphics (information design). By describing the task and approach, the various skills adding to the outcomes — a more traditional newspaper map and an appealing info graphics each for up to now 47 distinct topics — are demonstrated and discussed. This is meant to highlight the still existing need of important original carto-graphic skills in the otherwise rather IT-focused training of nowadays.

Modelling the distribution of human population based on satellite-derived information has become an important field of research, providing valuable input e.g. for human impact assessments related to the management of threatened ecosystems. However, few regional-scale studies have been conducted in developing countries, where detailed land cover data is usually absent, and the potential of very high resolution (VHR) satellite imagery in this context has not been explored yet. This study uses results obtained through object-based image analysis (OBIA) of QuickBird imagery for a subset of a highly populated rural area in western Kenya. Functions are established that approximate frequency distributions of QuickBird-derived locations of houses in relation to five factors. These factors are known to impact settlement patterns and data is available for the entire study area. Based on an overall probability coefficient (weight) calculated from the single functions, human population is redistributed at the smallest administrative level available (version A). In addition, the problem of artefacts remaining at administrative boundaries is addressed by combining the approach with the pycnophylactic smoothing algorithm ( Tobler, 1979 ) (version B). The results show distinct patterns of population distribution, with particular influence of rivers/streams and slope, while version B in addition is free of boundary artefacts. Despite some limitations compared to models based on detailed land cover data (e.g. the ability of capturing abrupt changes in population density), a visual and numerical evaluation of the results shows that using houses as classified from VHR imagery for a study area subset works well for redistributing human population at the regional level. This approach might be suitable to be applied also in other regions of e.g. sub-Saharan Africa.

Combining spatially explicit land cover data from remote-sensing and faunal data from field observations is increasingly applied for landscape-scale habitat and biodiversity assessments, but without modelling changes quantitatively over time. In a novel approach, we used a long-term time series including historical map data to predict the influence of one century of tropical forest change on keystone species or indicator groups in the Kakamega–Nandi forests, western Kenya. Four time steps of land cover data between 1912/13 and 2003, derived from Landsat satellite imagery, aerial photography and old topographic maps, formed the basis for extrapolating species abundance data on the army ant Dorylus wilverthi, the guild of ant-following birds and three habitat guilds of birds differing in forest dependency. To predict the species' spatio-temporal distribution, we combined spatially explicit geographical information system (GIS)-based modelling with statistical modelling, that is, ordinary least square (OLS) ...

Summary 1. It is important to document changes in the population sizes of species to justify and implement conservation programmes. This is often hampered by the absence of historical population count data, particularly for tropical animal species. 2. Here, we developed a predictive habitat distribution model (PHDM) for the army ant Dorylus wilverthi, a keystone species of Central African rainforests. We applied the model to forest cover data in western Kenya from 1913 to 2003 in order to estimate changes in the distribution and population size over the last century. The model was based on a large data set including abundance data of 51 repeatedly monitored 500 m transects in forest and non-forest habitats. 3. Forest cover within 1400 m of the transect lines explained 58% of the variation in abundance of D. wilverthi. The model predicts that the colony abundance of the army ant exponentially increases with increasing forest cover and that colonies are absent from landscapes with less than 11% forest cover. 4. Applying the PHDM to historical and recent forest cover data predicts a 52% decline in the population size of D. wilverthi (from 2801 to 1346 colonies) between 1913 and 2003. Under a worst-case scenario in which the forest area is reduced to the current national/nature reserves, the population size would decrease to fewer than 300 colonies, which is probably too low to ensure the long-term survival of the species. 5. Synthesis and applications. Our study demonstrates that the application of a PHDM on land-cover change time series data may give valuable insights into changes in the population size of species for which no historical population count data are available. Using this approach, we revealed a significant decline in population size of the army ant D. wilverthi over the last century. High protection status should be applied to all of the remaining forest area to prevent the population becoming regionally threatened and to facilitate long-term conservation of this keystone species in Kenya.

Damit die Forschungsergebnisse aus dem BIOTA-Ostafrika-Projekt von direktem, anwendbarem Nutzen sind — hier fur ein partizipatorisches Waldmanagement des Kakamega Forest in Westkenia —, gilt es, die verschiedenen Bevolkerungsgruppen zu informieren, sie zu sensibilisieren und so zu verandertem Handeln zu bewegen. Aus umfangreichen Geodaten entstandene, interaktive Visualisierungen werden vorgestellt und ihr moglicher Einsatz diskutiert. Erkenntnisse aus ersten Untersuchungen bzgl. ihrer Nutzlichkeit vor Ort zeigen die Herausforderungen — Kenianer sind mit dem Kartenlesen nicht vertraut —, aber auch ihr Potential.

A means of deriving a disturbance index reflecting forest use history is demonstrated here to establish a disturbance gradient and enable comparison of different forest areas within and across individual forests. Detailed reference is made to Kakamega Forest in western Kenya for which a long-term time series has been established, although the study is spread to four further forests in Kenya and Uganda. A wide variety of sources are drawn upon for spatially resolved data that are integrated in a geographic information system. Three indices are derived: for commercial disturbance, local disturbance, and forest cover change. Results show a wide range of disturbance values (from low to heavy) for the research sites within Kakamega Forest, while results for Budongo and Mabira Forest sites show low and moderate levels, respectively. Correlations of low disturbance levels with nature or national reserves appear to be marked, while a correlation of disturbance with differing management authority is also suggested with Kenya Wildlife Service achieving the lowest disturbance levels. Results from the index are reviewed against other means of estimating disturbance with the conclusion that disturbance evaluations should be both spatially resolved and long-term in nature. Resume Nous montrons ici un moyen de deriver un indice de perturbation qui reflete l’utilisation historique d’une foret et qui permet d’etablir un gradient de perturbation et de comparer differentes zones forestieres au sein d’une meme foret ou entre des forets differentes. Une reference detaillee est faite a la Foret de Kakamega, dans l’ouest du Kenya, pour laquelle une suite de periodes a eteetablie dans le long terme, mais l’etude s’etend aussi a quatre autres forets en Ouganda et au Kenya. Une grande variete de sources ont servi a obtenir des donnees spatiales qui sont integrees dans un SIG. Trois indices en sont derives : pour la perturbation d’origine commerciale, la perturbation locale et le changement de couvert forestier. Les resultats revelent une large gamme de valeurs de perturbations (de faible aelevee) pour les sites de recherche dans la foret de Kakamega alors que les resultats pour les sites de Budongo et de Mabira presentent respectivement des taux faibles a moderes. Les correlations entre de faibles taux de perturbation et les reserves naturelles ou nationales semblent marquees alors qu’une correlation est aussi suggeree entre les perturbations et les differentes autorites de gestion, le Kenya Wildlife Service obtenant le plus faible taux de perturbation. Les resultats obtenus avec ces indices sont compares a d’autres moyens d’estimer les perturbations, avec la conclusion que les evaluations des perturbations devraient etre determinees spatialement et se faire sur le long terme dans la nature.

Summary Anthropogenic forest fragmentation and other kinds of human disturbance, such as selective logging, can reduce the diversity of plant and animal species. To evaluate the impact of fragmentation and small-scale disturbance on forest regeneration, we assessed species richness and total abundance of adult trees in comparison with seedlings in the heavily fragmented and disturbed Kakamega Forest, western Kenya. In nine differently disturbed 1-ha study blocks distributed across the main forest and fragments, we mapped all trees >10 cm in diameter at breast height. Additionally, we established ninety 1-m 2 seedling plots within these 1-ha study blocks which were monitored over 2.5 years. We recorded altogether 74 species of adult trees (30–43 per block) and 64 seedling species (24–41 per block). Neither fragmentation nor small-scale disturbance had an impact on adult tree species richness or total tree abundance. Yet, fragmentation and especially small-scale disturbance significantly reduced seedling species richness, particularly of late-successional species. While human impact did not affect diversity of adults, the impoverished species richness of seedlings suggests a reduced potential for regeneration and a loss of tree diversity in the long-term.

Biodiversity in tropical rainforests is heavily influenced by land use/cover change (LUCC), but so far there have been few LUCC studies conducted in Africa. We present several methods that make use of remotely sensed data and landscape metrics and allow for assessment of the development of land cover and thus forest fragmentation and disturbance over a substantial period of time. The study covers Kakamega Forest and its associated forest areas in western Kenya, over the last 30 years. The accuracy of a supervised multispectral classification of Landsat time series data encompassing seven time steps between 1972 and 2001 is numerically assessed using ground truth reference data considering the 2001 time step. Here, buffering the forest areas by 1 km, highest user's accuracies for the forest classes ‘near natural + old secondary forest’ (87.50%), ‘secondary forest’ (80.00%) and ‘bushland/shrubs’ (81.08%) are revealed. Images of a spatially distributed fragmentation index derived from the land cover time series by applying a three by 3 pixel-sized moving window to determine forest pixels’ adjacency, highlight trends in forest fragmentation, e.g. the splitting into two separate forests along the Yala/Ikuywa corridor. Calculations of mean fragmentation indices for the Biodiversity Monitoring Transect Analysis in Eastern Africa (BIOTA-East Africa) focus research areas are used to evaluate the fragmentation index and to demonstrate its potential to extrapolate (e.g. biological) field findings in space and time. Here we argue for a correlation of the fragmentation indices results not only with forest management regimes, but with population distribution and accessibility (e.g. by roads). A cluster analysis applying the isodata-algorithm on the classification results of all seven times steps allows for a rapid visual assessment of the distinct pattern of typical land cover development trends since 1972. This reveals that parts of Kakamega Forest have experienced severe forest loss while others, especially in the north-east, show signs of succession. Resume La biodiversite des forets pluviales tropicales est fort influencee par les changements d'utilisation et de couverture du sol (land use/cover change– LUCC), mais il y a eu jusqu’a present fort peu d’etudes des LUCC en Afrique. Nous presentons plusieurs methodes qui utilisent des donnees de teledetection et d’ecologie spatiale et permettent d’evaluer le developpement du couvert forestier et donc de la fragmentation et des perturbations durant une periode substantielle. L’etude concerne la foret de Kakamega et toute les zones forestieres qui lui sont associees dans l'ouest du Kenya, au cours des 30 dernieres annees. L'exactitude d'une classification multispectrale de donnees sur des series temporelles Landsat, qui regroupent sept etapes chronologiques entre 1972 et 2001, est evaluee numeriquement en utilisant les donnees reelles de «verite terrain» correspondant a l’etape de 2001. En quadrillant la foret en unites d'un km de cote, l'utilisateur obtient les plus grandes precisions pour les classes de forets «presque naturelle + ancienne foret secondaire» (87,50%), «forets secondaires» (80,00%) et «Brousse/buissons» (81,08%). Des images de l'index de fragmentation spatialement distribue, derivees de series temporelles de la couverture du sol en appliquant une fenetre glissante de trois pixels sur trois pour determiner l'adjacence des pixels, mettent en evidence les tendances de la fragmentation de la foret, par exemple la separation en deux forets separees le long du corridor Yala/Ikuywa. Les calculs des indices de fragmentation moyens pour les zones centrales de recherche de BIOTA-est servent aevaluer l'indice de fragmentation et a demontrer son potentiel pour extrapoler des decouvertes (ex. biologiques) de terrain dans l'espace et le temps. Nous defendons ici une correlation des resultats des indices de fragmentation non seulement avec les regimes de gestion forestiere, mais aussi avec la distribution de la population et l'accessibilite (routes). Une analyse d'ensemble appliquant l'algorithme de seuillage aux resultats de l'application des sept etapes permet une evaluation visuelle rapide du pattern distinct des tendances typiques du developpement de la couverture vegetale depuis 1972. Ceci revele que des parties de la foret de Kakamega ont connu de graves pertes forestieres alors que d'autres, specialement au nord-est, presentent des signes de succession.

Im Projektverbund BIOTA-Ostafrika ist der Aufbau eines Pools gemeinsam genutzter Geodaten Grundvoraussetzung fur integrative Aussagen zu Veranderungen in der biologischen Artenvielfalt und ihrem Management. Die Konzeption des BIOTA-Ost-Geodatenkatalogs, die Notwendigkeit einer Harmonisierung heterogener Geodatensatze und ein Vergleich mit anderen Online-Geokatalogen sind Gegenstand des Artikels. Der Einsatz von WebGIS-Applikationen, die uber HTML ImageMapper und MapViewSVG realisiert werden und der Unterstutzung des Geodatenkatalogs und der Darstellung von Projektteilergebnissen dienen, wird diskutiert.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. Understanding the causes and effects of species invasions is a priority in ecology and conservation biology. One of the crucial steps in evaluating the impact of invasive species is to map changes in their actual and potential distribution and relative abundance across a wide region over an appropriate time span. While direct and indirect remote sensing approaches have long been used to assess the invasion of plant species, the distribution of invasive animals is mainly based on indirect methods that rely on environmental proxies of conditions suitable for colonization by a particular species. The aim of this article is to review recent efforts in the predictive modelling of the spread of both plant and animal invasive species using remote sensing, and to stimulate debate on the potential use of remote sensing in biological invasion monitoring and forecasting. Specifically, the challenges and drawbacks of remote sensing techniques are discussed in relation to: i) developing species distribution models, and ii) studying life cycle changes and phenological variations. Finally, the paper addresses the open challenges and pitfalls of remote sensing for biological invasion studies including sensor characteristics, upscaling and downscaling in species distribution models, and uncertainty of results.

For the region St-Martin-de-Londres (southern France), information on vegetation formations is available for 5 different years between 1946 and 1979. Isoprenoid emission factors are assigned according to dominant plant species that were related to the vegetation formations. Potential isoprenoid emissions are simulated with the help of the Solar Radiation Model (SORAM) considering spatial effects of the complex terrain as well as temporal effects of photosynthetically active radiation and surface temperature, the main controlling parameters for biogenic volatile organic compound (BVOC) emission. The SORAM is embedded in a geographic information system environment and considers a digital elevation model of the modeling domain. Results illustrate long-term changes of emission fluxes due to plant succession between 1946 and today. By comparing the daily amount of isoprenoid emissions over a time period of 34 years, today's totals have increased by a factor of 4.4 as compared to the 1946 modeling results. The results presented give an example of possible impact of increasing natural plant cover on isoprenoid emissions for the Mediterranean region. These scenarios at the landscape level further emphasize the need for detailed information concerning vegetation (species, distribution, coverage, biomass) as well as the need for reliable emission factors in order to improve inputs of potential BVOC emissions to tropospheric chemistry models.

The diurnal and seasonal emission course from plants is controlled by light and temperature. The pattern of light incident on a surface changes with time and space, which is most obvious in cast shadows. A complex GIS-based solar radiation model (SORAM) which is not restricted to certain test sites was developed. It is used for the first time to scale up biogenic emissions. Our main interest is to evaluate the effects on the amount of biogenic volatile organic compounds emitted caused by the 3-dimensional surface of either a canopy stand or a complex terrain. Therefore a digital elevation model represents the canopy surface of the St. Quercio pine/oak forest (Castelporziano, Italy). Temperature values are linked to the radiation output. This enables us to correct emission factors for light and temperature by using Tingey's (1980) and Guenther's (1993) emission algorithms. The methods are described and results presented for 26 May 1994 and 3 August 1994. The seasonality in the amount and composition of emitted compounds is clearly shown for P. pinea . Representing the canopy stand by a pseudo-3-dimensional surface instead of a surface with a constant height value reduces emission fluxes from Q. ilex by 40%. The “global” emission flux of the test site decreases by 20%. The results are compared with values derived from different measurement techniques and up-scaling methods. Suggestions are made to overcome the limitations of the pseudo-3-dimensional presentation of the canopy stand.

The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon(1-3). With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses(4-9). As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity. A critical constraint in addressing this question has been that data describing a broad array of biodiversity groups have been unavailable for a sufficiently large and representative sample of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world's major tropical regions. Our analysis reveals great variation in reserve `health': about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.

Remote sensing and geoinformation systems (GIS) play an important role in biodiversity research and management, strengthened by the increasing availability of very high resolution (VHR) satellite imagery. The interdisciplinary research project BIOTA East Africa has acquired five QuickBird scenes of early 2005 covering Kakamega Forest (western Kenya) and surrounding farmland. Pre-processing steps applied to the imagery included the correction of atmospheric and orographic influences as well as a mosaicing procedure. This study demonstrates the benefits to object-based image analysis: after a thorough pre-processing, a) objects of the same kind have more consistent characteristics, b) segments do not orientate themselves to the join of adjacent image swaths. A rule-based multi-resolution classification scheme is presented for deriving landscape structures in the agricultural matrix surrounding the forest. The high complexity of the farmland, with extremely small structured parcels, demands analysis strategies that make use of image derivates obtained from cadastral maps as well as ground truth information. Finally, the classification result is compared to one based on the unprocessed imagery, emphasizing implications of pre-processing for object-based image analysis.

Processes of deforestation, known to threaten tropical forest biodiversity, have not yet been studied sufficiently in East Africa. To shed light on the patterns and causes of human influences on protected forest ecosystems, comparisons of different study areas regarding land cover dynamics and potential drivers are needed. We analyze the development of land cover since the early 1970s for three protected East African rainforests and their surrounding farmlands and assess the relationship between the observed changes in the context of the protection status of the forests. Processing of Landsat satellite imagery of eight or seven time steps in regular intervals results in 12 land cover classes for the Kakamega-Nandi forests (Kenya) and Budongo Forest (Uganda) whereas ten are distinguished for Mabira Forest (Uganda). The overall classification accuracy assessed for the year 2001 or 2003 is similarly high for all three study areas (81% to 85%). The time series reveal that, despite their protection status, Kakamega-Nandi forests and Mabira Forest experienced major forest decrease, the first a continuous forest loss of 31% between 1972/1973 and 2001, the latter an abrupt loss of 24% in the late 1970s/early 1980s. For both forests, the temporally dense time series show short-term fluctuations in forest classes (e.g., areas of forest regrowth since the 1980s or exotic secondary bushland species from the 1990s onwards). Although selectively logged, Budongo Forest shows a much more stable forest cover extent. A visual overlay with population distribution for all three regions clearly indicates a relationship between forest loss and areas of high population density, suggesting population pressure as a main driver of deforestation. The revealed forest losses due to local and commercial exploitation further demonstrate that weak management impedes effective forest protection in East Africa.

Today, graduates seek employment in a global marketplace, regardless of the country in which they studied. Comparing academic programs helps students, academics and employers to make informed decisions about study options, program offerings and the employment of recent graduates. In this study, we juxtapose geospatial technologyrelated programs at three universities located in Europe, Africa and America. Initially, the authors contributed information about these programs through a questionnaire comprising several open-ended questions about the origins and development of the respective programs. Subsequently, the proportional thematic compositions of programs at the three universities were compared. As expected, this study was not without challenges. From the outset, we struggled with agreeing on terminology and semantics. Results of the study indicate that there is not a one-size-fits-all strategy for establishing, shaping and sustaining such programs. Program composition is guided by many factors, including staff expertise, university politics, legislation, attractiveness to students, technological developments, demands in the job market and requirements set by a professional body. Some of these factors are strongly influenced by the local (university) environment (e.g. staff expertise), others are of national relevance (e.g. legislation and a national professional body), while some apply globally (e.g. technological developments). The study illustrated how a comparison of proportional program composition can reveal significant differences and similarities that are not obvious when only content is compared. The compositional differences naturally result in graduates with different knowledge and skills that allow different career paths and meet different needs of the job market.

[1] Sensitivity studies for simulations of yearly cycles and terrain effects are presented for the St.-Martin-de-Londres region (southern France). Potential isoprenoid emissions are simulated using the Solar Radiation Model (SORAM), spatial effects of complex terrain, photosynthetically active radiation, and surface temperature. SORAM is embedded in a geographic information system (GIS) environment and considers a digital elevation model (DEM) of the model domain. Compared to the maximum case (i.e., no variation in emission factors and leaf area index (LAI)), seasonality in LAI for that Mediterranean-type landscape mainly covered by evergreen plant species resulted in an annual amount of 3.5% less for total isoprenoids. By including the intra-annual change in emission factors an additional 12.5% reduction was derived for the area. When the SORAM module that accounts for light extinction within the canopy was switched off, modeled yearly amount in emission increased by 48%. Complex terrain effects showed only a weak influence for the rather moderate terrain of the modeling domain (mean difference of approximately −2.5% in daily sums). However, sensitivity studies based on the DEM exaggerated by a factor of 2 (resulting in differences of −11.7% for the light- and temperature-dependent isoprenoids) revealed that in the case of pronounced relief or if highly resolved results are necessary, the orography should be considered when modeling the driving parameters of light and temperature.

Water scarcity is among the many problems faced today by many countries in the world, especially African countries. The Kakamega area in western Kenya is known for plenty of rainfall (around 2000 mm annually), however, rainwater harvesting (RHW) from roofs is not yet a common practice in the region. In this study, we determined the potential of RWH as an alternative or preferred source of safe water for domestic use. Spatial modelling techniques using amount of rainfall, census data and detailed information available from the classification of very high resolution QuickBird satellite imagery as input data were applied to implement various approaches. Four conceptual models were developed at three different levels of detail: the Kakamega-Nandi forests area (3900 km²), the QuickBird imagery covered area (473 km² of farmland) and Buyangu village (1.9 km²). The four models were implemented in ArcGIS ModelBuilder and reveal the potential of such spatially explicit simulations to guide planners and to demonstrate the benefits of RWH to the local people. In the Kakamega-Nandi forests area, it rains enough to meet the annual water demand of 7300 l per person almost throughout the entire area.

The emission mix and source strength of biogenic VOC compounds (BVOC) are strongly triggered by the development, distribution and plant mix of the vegetation. Both are additionally strongly influenced by synergistic effects of the environment on the plants, e.g. higher ozone concentration or water availability. They enhance the formerly mentioned effects but our knowledge of these processes is coarse and therefore only partially considered in actual biogenic emission inventories. The definition of effective directives in environmental policy for the mitigation of hazardous photosmog episodes requires a sound knowledge of emissions with a high temporal and spatial resolution from both anthropogenic and biogenic sources (e.g. forest ecosystems). Anthropogenic emissions are thought to be quite well characterised with respect to emitted compounds and source strength, but large uncertainties exist for the biogenic emissions despite their great importance for the formation of photosmog.

Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle direct from biodiversity-related indirect effects of human disturbance on multiple ecosystem processes. Fragmentation increased decomposition and reduced antbird predation, while selective logging consistently increased pollination, seed dispersal and army-ant raiding. Fragmentation modified species richness or community composition of five taxa, whereas selective logging did not affect any component of biodiversity. Changes in the abundance of functionally important species were related to lower predation by antbirds and higher decomposition rates in small forest fragments. The positive effects of selective logging on bee pollination, bird seed dispersal and army-ant raiding were direct, i.e. not related to changes in biodiversity, and were probably due to behavioural changes of these highly mobile animal taxa. We conclude that animal-mediated ecosystem processes respond in distinct ways to different types of human disturbance in Kakamega Forest. Our findings suggest that forest fragmentation affects ecosystem processes indirectly by changes in biodiversity, whereas selective logging influences processes directly by modifying local environmental conditions and resource distributions. The positive to neutral effects of selective logging on ecosystem processes show that the functionality of tropical forests can be maintained in moderately disturbed forest fragments. Conservation concepts for tropical forests should thus include not only remaining pristine forests but also functionally viable forest remnants.

Fruiting trees in degraded areas are attractive for frugivorous birds and may become centers of regeneration. However, a number of tree species in degraded areas are exotic species. Thus, the question arises whether these exotic species can also act as foci for forest regeneration. In the farmland adjacent to Kakamega Forest, Kenya, we investigated the frugivore assemblage in, and seed rain and seedling establishment under, 29 fruiting exotic guava trees (Psidium guajava) at different distances to the forest. The results show that 40 frugivorous bird species visited guava trees. All of the seed and 82 percent of the seedling species found under the treecrowns were animal dispersed, 58 and 57 percent of them late-successional species, respectively. Path analysis revealed that the abundance of frugivorous birds, seeds, and seedlings did not decrease up to a distance of 2 km from the forest. Surprisingly, the abundance of frugivorous shrubland birds, animal-dispersed seeds, and late-successional seeds showed an increase with increasing distance from forest. Even though they are exotics, fruiting guava trees may have a positive effect on forest regeneration and might prove valuable for management plans concerning forest restoration.