A remote sensing perspective: mapping the human footprint in the Zambezi region of Namibia.

The “human footprint” can be used as a general proxy to estimate human activities across the landscape. The human footprint in the Zambezi Region of Namibia is critically important for regional management of conservation efforts and land use planning. The land covers in the Zambezi Region are characteristically difficult to separate spectrally, due to a highly heterogeneous savanna landscape. Object Based Image Analysis (OBIA) and Random Forest (RF) methods are notable for their ability to improve classification accuracies of remotely sensed imagery. In this study, I investigate the extent of the human footprint in the Zambezi Region of Namibia, using OBIA, RF, and a hybrid Object-based Random Forest approach. Results highlight that Object-based approaches score 5-10% better than a pixel-based RF approach in overall accuracy. Further investigation into the human footprint of the Zambezi Region is necessary for regional and local conservation and sustainable development

Micro-topography associated to forest edges

Forest edges are often defined as the discontinuity between the forest habitat and an adjacent open habitat, thus they are based on a clear difference in the structure of the dominant vegetation. However, beside this very general definition, in the field we can observe a large diversity of edges, with often different kinds of micro-topography features: bank, ditch, stone wall, path, etc. As these elements are rather common in many temperate forest edges, it seems important to start to characterize them more clearly and with consistency. From a set of observations in south-western France, we build a first typology of the micro-topographic elements associated to forest edges. For each of them we describe the process, natural or human induced, at their origin, and according to the literature available, we identify some of their key ecological roles. Banks, generated by the differential erosion between forest and crops along slopes, are especially analyzed since they are the most common micro-topographic element in our region. It offers many micro-habitat conditions in the soil used by a wide range of species, notably by several bee species. More research is required to study in details the importance of such micro-topographic elements

Exploring the future land use-biodiversity-climate nexus in East Africa: an application of participatory scenario analysis

Climate change and land-use-land-cover change (LULCC) are expected to have major impacts on global biodiversity. In highly diverse tropical moist forests, future biodiversity trajectories will also depend on political and societal will to undertake the changes needed to reduce those impacts. We present a framework to build participatory spatially-explicit scenarios that can be used to analyse the biodiversity-climate-land-change tradeoffs, which we applied at different scales in East Africa. In Tanzania, under the business-as-usual pattern of economic growth, the Eastern Arc Mountains forests and biodiversity will be heavily impacted on, with increasing pressure on protected areas. Increasing variability of rainfall and temperature are likely to impact on where the LULCC are going to be, with the mountains likely to be refuges that are even more important for local communities. That may intensify impacts on biodiversity. In Taita Hills (Kenya) and Jimma Highlands (Ethiopia), stakeholders expected that adaptation interventions to climate change would generally improve biodiversity state. Preliminary data on birds community diversity in Taita Hills showed that though agroforestry system supports higher diversity than natural forest, species richness of rarer forest specialists remained highest within natural forests. Anticipating future conservation and agriculture interaction under climate change may contribute to set spatial priorities for intervention sites. Further investigations are required that could benefit from integrating local stakeholders’ perceptions and visions for the future

An assessment of tropical dryland forest ecosystem biomass and climate change impacts in the Kavango-Zambezi (KAZA) region of Southern Africa

The dryland forests of the Kavango-Zambezi (KAZA) region in Southern Africa are highly susceptible to disturbances from an increase in human population, wildlife pressures and the impacts of climate change. In this environment, reliable forest extent and structure estimates are difficult to obtain because of the size and remoteness of KAZA (519,912 km²). Whilst satellite remote sensing is generally well-suited to monitoring forest characteristics, there remain large uncertainties about its application for assessing changes at a regional scale to quantify forest structure and biomass in dry forest environments. This thesis presents research that combines Synthetic Aperture Radar, multispectral satellite imagery and climatological data with an inventory from a ground survey of woodland in Botswana and Namibia in 2019. The research utilised a multi-method approach including parametric and non-parametric algorithms and change detection models to address the following objectives: (1) To assess the feasibility of using openly accessible remote sensing data to estimate the dryland forest above ground biomass (2) to quantify the detail of vegetation dynamics using extensive archives of time series satellite data; (3) to investigate the relationship between fire, soil moisture, and drought on dryland vegetation as a means of characterising spatiotemporal changes in aridity. The results establish that a combination of radar and multispectral imagery produced the best fit to the ground observations for estimating forest above ground biomass. Modelling of the time-series shows that it is possible to identify abrupt changes, longer-term trends and seasonality in forest dynamics. The time series analysis of fire shows that about 75% of the study area burned at least once within the 17-year monitoring period, with the national parks more frequently affected than other protected areas. The results presented show a significant increase in dryness over the past 2 decades, with arid and semi-arid regions encroaching at the expense of dry sub-humid, particularly in the south of the region, notably between 2011-2019

Connectivity at the Large Carnivore Scale: The Kafue-Zambezi Interface

The growth and expansion of human populations and resource demands is driving large scale fragmentation and loss of wildlife habitat, isolating wildlife populations and pushing many species towards extinction at local to global scales. Attempts to promote connectivity between wildlife managed areas at transboundary scales has been proposed as a solution to negative effects associated with population isolation. Such approaches commonly require the maintenance of wildlife populations throughout human-dominated landscapes subject to various degrees of effective protection.The aims of this study are to (1) assess the status of the large carnivore guild throughout ten wildlife managed areas comprising the Zambian component of Kavango-Zambezi Transfrontier Conservation Area between Kafue National Park and the Simalaha Wildlife Recovery Sanctuary on the Zambezi River; (2) model habitat suitability and connectivity in this landscape for Lion, Leopard and Spotted hyena; and (3) develop a site-specific map of human footprint pressure for the landscape and test if it can be used a proxy for determining the occurrence of these three species. And further, explore if there are thresholds in human footprint pressure beyond which species are likely extirpated from wildlife managed areas.Methods included library studies to determine historical status of the large carnivore guild and twenty-six common prey species, spoor tracking in conjunction with qualitative surveys and supplemental data analysis to ascertain species current distribution, remote sensing with ground-truthing to build landcover maps, Maximum Entropy and Current Flow models, and extensive use of Geographic Information Systems.The findings conclude that there have been large scale losses in species assemblages throughout majority of southern wildlife managed areas, including the Simalaha Wildlife Recovery Sanctuary. However, no detectable changes were evident in Kafue National Park and surrounding Game Management Areas. Human activities are limiting habitat suitability and scope for occurrence in central southern areas of the landscape, with the likelihood of a connectivity bottleneck occurring. There is significant overlap in habitat requirements and scope for species movement. Human footprint pressure models appear to demonstrate utility as a proxy measure for occurrence of our large carnivore subset, though require some refinements and supplemental data layers to increase predictive power. Human footprint pressure at the wildlife managed area scale indicates threshold levels at which target species occur or are locally extirpated.Analyses have identified important additions to the existing wildlife managed area network in Open communal land that could provide valuable habitat and connectivity for target species given effective management and finance, including containment of negative human disturbance variables modelled (agro-pastoralist activities and infrastructure development). The effects of poaching are also hypothesized to be a significant driver limiting species persistence.Continued expansion of human population, settlement and agro-pastoralist activities will limit scope for expansion of large carnivores and their principle prey throughout the Kafue-Zambezi interface, effectively severing connectivity and isolating the Greater Kafue System from adjacent wildlife managed areas in the Kavango-Zambezi Transfrontier Conservation Area.Narratives surrounding the development of wildlife-based land uses and species-level connectivity benefit from the application of conservation science and generation of empirical data to guide management

Exploring the Effect of Human and Animal Population Growth on Vector-Borne Disease Transmission with an Agent-Based Model of Rhodesian Human African Trypanosomiasis in Eastern Province, Zambia

This paper presents the development of an agent-based model (ABM) to investigate Trypanosoma brucei rhodesiense human African trypanosomiasis (rHAT) disease transmission. The ABM model, fitted at a fine spatial scale, was used to explore the impact of a growing host population on the spread of disease along a 75 km transect in the Luangwa Valley, Zambia. The model was used to gain a greater understanding of how increases in human and domestic animal population could impact the contact network between vector and host, the subsequent transmission patterns, and disease incidence outcomes in the region. Modelled incidence rates showed increases in rHAT transmission in both humans and cattle. The primary demographic attribution of infection switched dramatically from young children of both sexes attending school, to adult women performing activities with shorter but more frequent trips, such as water and firewood collection, with men more protected due to the presence of cattle in their routines. The interpretation of model output provides a plausible insight into both population development and disease transmission in the near future in the region and such techniques could aid well-targeted mitigation strategies in the future

Exploring the Effect of Human and Animal Population Growth on Vector-Borne Disease Transmission with an Agent-Based Model of Rhodesian Human African Trypanosomiasis in Eastern Province, Zambia

This paper presents the development of an agent-based model (ABM) to investigate Trypanosoma brucei rhodesiense human African trypanosomiasis (rHAT) disease transmission. The ABM model, fitted at a fine spatial scale, was used to explore the impact of a growing host population on the spread of disease along a 75 km transect in the Luangwa Valley, Zambia. The model was used to gain a greater understanding of how increases in human and domestic animal population could impact the contact network between vector and host, the subsequent transmission patterns, and disease incidence outcomes in the region. Modelled incidence rates showed increases in rHAT transmission in both humans and cattle. The primary demographic attribution of infection switched dramatically from young children of both sexes attending school, to adult women performing activities with shorter but more frequent trips, such as water and firewood collection, with men more protected due to the presence of cattle in their routines. The interpretation of model output provides a plausible insight into both population development and disease transmission in the near future in the region and such techniques could aid well-targeted mitigation strategies in the future

Ecological effects of willow and poplar invasions at the Río Negro in northern Patagonia, Argentina

Species of the Salicaceae family, particularly Salix species and their hybrids, are typical invaders of river systems throughout the world with severe consequences for native ecosystems. Along Patagonian streams, riparian softwood forests structured by dominant invasive Salicaceae are increasing significantly in abundance, area and species diversity. The region of the Río Negro in northern Patagonia has been invaded by several woody plant species with a dramatical increase in the recent decades. The most dominant taxa are willows of the Salix alba L. - Salix fragilis L. complex, a hybrid of this complex and Salix babylonica L. and Populus spp. Additionally, Elaeagnus angustifolia Willd. and Tamarix spp. have been spreading aggressively in recent years. This thesis provides information on the possible consequences of these invasions for Salix humboldtiana Willd., the only native woody species along the Río Negro, due to interspecific competition and invasion development. Vegetative reproduction is especially for S. fragilis and its hybrids of great importance for the colonisation of new habitats and probably is the most important reason for their invasion success. In the first study (Chapter 2), a greenhouse experiment was conducted in order to assess the vegetative reproduction capacities of native and invasive Salicaceae (S. humboldtiana, S. × rubens Schrank, a S. babylonica hybrid and Populus spec.) under various soil composition and moisture gradients. The invasive willow hybrids showed better vegetative re-sprouting capacities and performed sinificantly better than S. humboldtiana and Populus spec. They developed more living cuttings as well as more and longer sprouts under all treatment combinations and they generated significantly higher above- and belowground biomass. After completely removing the shoot and root biomass of the cuttings re-sprouting capacities were evaluated in a second experiment. Again, the invasive willows had a superior re-sprouting ability and growth performance. These results demonstrate that invasive willows are able to establish more successfully by vegetative reproduction than the native willow and that they have a higher re-sprouting potential after disturbances. This ability in combination with the advantages of vegetative reproduction compared to generative reproduction seems to be the key factor for invasive success and, simultaneously, a potential threat for S. humboldtiana through out-competition. In a further approach (Chapter 3), age structure analyses were carried out which revealed that mixed adult forest stands are the results of joint establishment events with all Salicaceae taxa involved. The analysed 20 stands on islands had low mean ages <15 years. Investigation on growth performance (basal area, crown diameter, tree hight and crown base hight) of adult stands revealed that non-native willows and poplars are able to actively displace the native S. humboldtiana by competitive strength: A significant better growth performance with e.g. higher basal area and crown diameter was found for the non-native willows in adult life stage. Furthermore, adult S. humboldtiana was more frequent at the middle river stretch, while invasive willow hybrids showed an opposing pattern suggesting a downstream directed invasion process. In order to evaluate the competition potential of invasive alien woody plants (Salicaceae, Elaeagnus and Tamarix) for S. humboldtiana, habitat distribution models for different life stages (seedling, juvenile, adult) were developed (Chapter 4). The objective was to identify ecological niches and relationships between species occurrence and different abiotic factors. Data on species (presence/ absence) and explanatory environmental variables were gathered in the field on 167 plots using a grid-based, stratified-randomized sampling design. The environmental variables flood duration, the amount of gravel and the location (upper or middle river valley) proved to be the best explanatory variables to describe the occurrence of the species. For all life stages, a strong niche overlap could be observed for S. humboldtiana and invasive taxa, particularly Salicaceae, with no remaining exclusive habitat for the native willow. Additionally, investigations on vegetation change offer insights into invasion development (Chapter 5). Multispectral satellite images from the years 1986 and 2003 of the upper Río Negro were used to detect land cover changes. This study demonstrated that during this time period floodplain forests expanded considerably their distribution area by almost 150%, probably due to the explosive spread of non-native species. The results of this thesis can be summarized as follows: Invasive willows have significant better vegetative reproduction and re-sprouting capacities, better growth performances in the adult life stage and exhibit a strong niche overlap with the native willow species. These findings indicate a high competition potential of invasive Salicaceae with, consequently, a possible out-competition and suppression of S. humboldtiana

Geospatial environmental data modelling applications using remote sensing, GIS and spatial statistics

This thesis presents novel modelling applications for environmental geospatial data using remote sensing, GIS and statistical modelling techniques. The studied themes can be classified into four main themes: (i) to develop advanced geospatial databases. Paper (I) demonstrates the creation of a geospatial database for the Glanville fritillary butterfly (Melitaea cinxia) in the Åland Islands, south-western Finland; (ii) to analyse species diversity and distribution using GIS techniques. Paper (II) presents a diversity and geographical distribution analysis for Scopulini moths at a world-wide scale; (iii) to study spatiotemporal forest cover change. Paper (III) presents a study of exotic and indigenous tree cover change detection in Taita Hills Kenya using airborne imagery and GIS analysis techniques; (iv) to explore predictive modelling techniques using geospatial data. In Paper (IV) human population occurrence and abundance in the Taita Hills highlands was predicted using the generalized additive modelling (GAM) technique. Paper (V) presents techniques to enhance fire prediction and burned area estimation at a regional scale in East Caprivi Namibia. Paper (VI) compares eight state-of-the-art predictive modelling methods to improve fire prediction, burned area estimation and fire risk mapping in East Caprivi Namibia. The results in Paper (I) showed that geospatial data can be managed effectively using advanced relational database management systems. Metapopulation data for Melitaea cinxia butterfly was successfully combined with GPS-delimited habitat patch information and climatic data. Using the geospatial database, spatial analyses were successfully conducted at habitat patch level or at more coarse analysis scales. Moreover, this study showed it appears evident that at a large-scale spatially correlated weather conditions are one of the primary causes of spatially correlated changes in Melitaea cinxia population sizes. In Paper (II) spatiotemporal characteristics of Socupulini moths description, diversity and distribution were analysed at a world-wide scale and for the first time GIS techniques were used for Scopulini moth geographical distribution analysis. This study revealed that Scopulini moths have a cosmopolitan distribution. The majority of the species have been described from the low latitudes, sub-Saharan Africa being the hot spot of species diversity. However, the taxonomical effort has been uneven among biogeographical regions. Paper III showed that forest cover change can be analysed in great detail using modern airborne imagery techniques and historical aerial photographs. However, when spatiotemporal forest cover change is studied care has to be taken in co-registration and image interpretation when historical black and white aerial photography is used. In Paper (IV) human population distribution and abundance could be modelled with fairly good results using geospatial predictors and non-Gaussian predictive modelling techniques. Moreover, land cover layer is not necessary needed as a predictor because first and second-order image texture measurements derived from satellite imagery had more power to explain the variation in dwelling unit occurrence and abundance. Paper V showed that generalized linear model (GLM) is a suitable technique for fire occurrence prediction and for burned area estimation. GLM based burned area estimations were found to be more superior than the existing MODIS burned area product (MCD45A1). However, spatial autocorrelation of fires has to be taken into account when using the GLM technique for fire occurrence prediction. Paper VI showed that novel statistical predictive modelling techniques can be used to improve fire prediction, burned area estimation and fire risk mapping at a regional scale. However, some noticeable variation between different predictive modelling techniques for fire occurrence prediction and burned area estimation existed.Ihmisen toiminnan seurauksena ympäristön tila on heikentynyt kiihtyvällä vauhdilla. Ilmasto lämpenee, metsähakkuut ja metsäpalot lisääntyvät ja luonnon monimuotoisuus on katoamassa. Ympäristöongelmia ja -uhkia voidaan tutkia ja mallintaa geoinformatiikan menetelmin ja metodein: kaukokartoituksen, paikkatietojärjestelmien (GIS) sekä spatiaalis-tilastollisten ennustemallien avulla. Väitöskirjassa tutkittiin geoinformatiikan menetelmin geospatiaalista aineistoa hyväksi käyttäen: (i) Täpläverkkoperhosen (Melitaea cinxia) esiintymistä Ahvenanmaalla; (ii) Lehtimittarin (Scopulini moths; Lepidoptera: Geometridae, Sterrhinae) esiintymisen spatiaalis-temporaalista levinneisyyttä ja diversiteettiä globaalissa mittakaavassa; (iii) alkuperäismetsien häviämistä ja (iv) asutuksen levinneisyyttä Taita Hills -ylänköalueella Keniassa, sekä (v ja vi) savannipalojen esiintymistä ja paloarpien laajuuden arviointia Itä-Kaprivilla, Namibiassa. Tulokset: (i) Ahvenanmaalla esiintyvälle Täpläverkkoperhoselle luotiin paikkatietokanta, jonka avulla selvitettiin lajin metapopulaation spatiaalis-temporaalisia tekijöitä. Tärkein tulos todisti että paikallisilmaston vaikutus on yksi merkittävimmistä tekijöistä Täpläverkkoperhosen populaatioiden koon vaihtelussa. (ii) Paikkatietomenetelmin pystyttiin selvittämään Lehtimittarin (Scopulini moths; Lepidoptera: Geometridae, Sterrhinae) globaali maantieteellinen levinneisyys ja diversiteetti. Lajia tavataan ympäri maailmaa paitsi arktisilla alueilla. Pääosa lajeista on löydetty troppisilta alueilta. Diversiteetti on erityisen runsasta Saharan eteläpuoleisessa Afrikassa. (iii) Taita Hills ylänköalueella alkuperäismetsät ovat vähentyneet 50% (260 hehtaaria) vuodesta 1955 vuoteen 2004. Kuitenkin metsäpinta-ala oli Taita Hillsin ylänköalueella pienentynyt vain 2% johtuen metsänistutuksista. Maankäytön muutostulkintaan perustuen Taita Hills ylänköalueen alkuperäismetsät ovat pääosin muuttuneet maatalousmaaksi. Alkuperäismetsien tilalle on myös istutettu ns. eksoottisia lajikkeita kuten eukalyptusta, joka on heikentänyt metsien laatua, jolla on haitalliset vaikutukset mm. eliölajien monimuotoisuuteen Taita Hillsin alueella. (iv) Taita Hills ylänköalueen asutuksen levinneisyyttä voidaan mallintaa geospatiaalisilla karttatasoilla ja spatiaalis-tilastollisilla ennustemenetelmillä. Tutkimuksessa ilmeni, että satelliittikuvalta saadut ensimmäisen asteen tilastolliset tekstuuripiirteet ja toisen asteen tilastolliset tekstuuripiirteet, jotka perustuvat ns. Haralickin tekstuuripiirteiden yhtenevyysmatriisiin, olivat parhaita muuttujia selittämään asutuksen levinneisyyttä. Tutkimus paljasti että asutuksen mallintamiseen ei välttämättä tarvita satelliittikuvalta luokiteltua maankäyttökarttatasoa, sillä ensimmäisen ja toisen asteen tilastolliset tekstuuripiirteet olivat parempia selittäviä muuttujia ennustemalleissa. (v) Itä-Kaprivilla spatiaalis-tilastollisella ennustemallilla; yleistetty lineaarinen regressio (generalized linear model, GLM) voidaan arvioida paloalueiden laajuus paikallistasolla tarkemmin kuin käyttämällä olemassa olevaa MODIS satelliittiin perustuvaa (MCD45A1) globaalia paloaluemallia. Spatiaalis-tilastollisissa malleissa on kuitenkin huomioitava palojen spatiaalinen autokorrelaatio kalibrointiprosessissa. (vi) Kahdeksaa eri spatiaalis-tilastollista ennustemallinnusmenetelmää verrattiin palojen esiintymisen ja paloalueiden laajuuden analyysissä Itä-Kaprivilla. GBM (Generalized boosting methods) -menetelmä osoittautui parhaaksi sekä palojen esiintymisen ja paloalueiden laajuuden mallintamisessa. Ennustemalleilla pystyttiin arvioimaan paloalueiden laajuus ja paloriskialueet tarkemmin kuin käyttämällä olemassa olevaa MODIS satelliittiin perustuvaa (MCD45A1) globaalia paloaluemallia

Biodiversity and Protected Areas

Biodiversity and Protected Areas assembles twelve topics from around the world, illustrating the complexities and promise of addressing the biodiversity crisis. Authors from Mongolia, Africa, India, Canada, Iraq, and the United States dwell on particular aspects and challenges relevant to those regions. Lessons and approaches from interesting localities, coupled with global analyses give the reader a synthetic view of emerging problems. The opportunities for understanding common issues across different geographies abound, such as comparing local conservation in sub-Saharan Africa with a distribution of very small protected areas in Massachusetts. Several topics will be of immediate interest to policymakers. The book is illustrated with numerous color maps and figures and the authors strove for clear, uncomplicated writing. The editors provide an overview of chapters, placing them in the context of other biodiversity and protected area literature. Students and conservationists attempting to broaden their views of biodiversity and protected areas should find this collection to be interesting